Among the alloying-type anodes,elemental Sb possesses the suitable yet safe plateau,simple lithiation pathway,small voltage polarization,high conductivity,and superior cycle stability.However,challenge is that its int...Among the alloying-type anodes,elemental Sb possesses the suitable yet safe plateau,simple lithiation pathway,small voltage polarization,high conductivity,and superior cycle stability.However,challenge is that its intrinsic capacity is rather low(660 mAh g^(-1)),<1/6 of silicon.Herein,we propose a seamless integration strategy by merging the voltage and capacity of phosphorus and antimony into a solid solution alloy.Interestingly,the enlistment of P is found greatly enlarge the capacity from 660 to 993 mAh g^(-1) for such Sb_(30)P_(30) solid solution,while maintaining a single and stable discharge plateau(~0.79 V)similar to elemental Sb.Various experimental characterizations including XPS,PDF,Raman,and EDS mapping reveal that in such a material the P and Sb atoms have interacted with each other to form a homogenous solid solution alloy,rather than a simple mixing of the two substances.Thus,the Sb_(30)P_(30) exhibits superior rate performances(807 mAh g^(-1) at 5000 mA g^(-1))and cyclability(821 mAh g^(-1) remained after 300 cycles).Furthermore,such Sb_(60-x)P_(x) alloys can even deliver 621 mAh g^(-1) at30℃,which can be served as the alternative anode materials for high-energy and low-temperature batteries.This unique seamless integration strategy based on solid solution chemistry can be easily leveraged to manipulate the capacity of other electrode materials at similar voltage.展开更多
Low-temperature performance and high-rate discharge capability of AB5-type non-stoichiometric hydrogen storage are studied. X-ray diffraction(XRD),pressure-composition-temperature(PCT) curves and electrochemical imped...Low-temperature performance and high-rate discharge capability of AB5-type non-stoichiometric hydrogen storage are studied. X-ray diffraction(XRD),pressure-composition-temperature(PCT) curves and electrochemical impedance spectroscopy(EIS) are applied to characterize the electrochemical properties of ABx(x=4.8,4.9,5.0,5.1,5.2) alloys. The results show that the non-stoichiometric alloys exhibit better electrochemical properties compared with that of the AB5 alloy.展开更多
Achieving an in-depth understanding of the nexus between temperature and phase transitions is paramount for advancing the electrochemical efficiency of aqueous zinc ion batteries.Yet,the intricacies of electrochemical...Achieving an in-depth understanding of the nexus between temperature and phase transitions is paramount for advancing the electrochemical efficiency of aqueous zinc ion batteries.Yet,the intricacies of electrochemical interactions,particularly those associated with the structural evolution over extended periods,remain enigmatic.In this research,we leverage V_(2)O_(5) as an initial structural model of crystals to demystify the kinetics of electrode reactions and the decay mechanism of global electrochemical degradation by meticulously controlling the crystal defects via applying different mechanical grounding intensities.It is noted that the grounding V_(2)O_(5)(GVO)can exhibit a stable crystal structure that suppresses the dissolution/shuttling of vanadium and mitigates Zn anodes by-products caused by electrochemical processes.Thus,the GVO is utilized as the cathode material,achieving excellent Zn storage capacity at both room temperature and low temperatures,e.g.,380 and 246 mA h g^(−1) at room temperature and−20℃,respectively.Remarkably,the GVO cathode retains a specific capacity of 160 mA h g^(−1) with a capacity retention rate of 99%after 1500 cycles at−20℃ and 1 A g^(−1).This work provides a novel insight into the electrochemical crosstalk behavior of aqueous zinc-ion batteries(AZIBs)in a wide range of temperatures.展开更多
Sodium-ion batteries (NIBs) have become an ideal alternative to lithium-ion batteries in the field of electrochemical energy storage due to their abundant raw materials and cost-effectiveness. With the progress of hum...Sodium-ion batteries (NIBs) have become an ideal alternative to lithium-ion batteries in the field of electrochemical energy storage due to their abundant raw materials and cost-effectiveness. With the progress of human society, the requirements for energy storage systems in extreme environments, such as deep-sea exploration, aerospace missions, and tunnel operations, have become more stringent. The comprehensive performance of NIBs at low temperatures (LTs) has also become an important consideration. Under LT conditions, challenges such as increased viscosity of electrolyte, abnormal growth of solid electrolyte interface, and poor contact between collector and electrode materials emerge. The aforementioned issues hinder the diffusion kinetics of sodium ions (Na^(+)) at the electrode/electrolyte interface and cause rapid degradation of battery performance. Consequently, the optimization of electrolyte composition and cathode/anode materials becomes an effective approach to improve LT performance. This review discusses the conduction behavior and limiting factors of Na^(+) in both solid electrodes and liquid electrolytes at LT. Furthermore, it systematically reviews the recent research progress of LT NIBs from three aspects: cathode materials, anode materials, and electrolyte components. This review aims to provide a valuable reference for developing high-performance LT NIBs.展开更多
CsPbX_(3)-based(X=I,Br,Cl)inorganic perovskite solar cells(PSCs)prepared by low-temperature process have attracted much attention because of their low cost and excellent thermal stability.However,the high trap state d...CsPbX_(3)-based(X=I,Br,Cl)inorganic perovskite solar cells(PSCs)prepared by low-temperature process have attracted much attention because of their low cost and excellent thermal stability.However,the high trap state density and serious charge recombination between low-temperature processed TiO_(2)film and inorganic perovskite layer interface seriously restrict the performance of all-inorganic PSCs.Here a thin polyethylene oxide(PEO)layer is employed to modify TiO_(2)film to passivate traps and promote carrier collection.The impacts of PEO layer on microstructure and photoelectric characteristics of TiO_(2)film and related devices are systematically studied.Characterization results suggest that PEO modification can reduce the surface roughness of TiO_(2)film,decrease its average surface potential,and passivate trap states.At optimal conditions,the champion efficiency of CsPbI_(2)Br PSCs with PEO-modified TiO_(2)(PEO-PSCs)has been improved to 11.24%from 9.03%of reference PSCs.Moreover,the hysteresis behavior and charge recombination have been suppressed in PEO-PSCs.展开更多
Purpose–The type 120 emergency valve is an essential braking component of railway freight trains,butcorresponding diaphragms consisting of natural rubber(NR)and chloroprene rubber(CR)exhibit insufficientaging resista...Purpose–The type 120 emergency valve is an essential braking component of railway freight trains,butcorresponding diaphragms consisting of natural rubber(NR)and chloroprene rubber(CR)exhibit insufficientaging resistance and low-temperature resistance,respectively.In order to develop type 120 emergency valverubber diaphragms with long-life and high-performance,low-temperatureresistant CR and NR were processed.Design/methodology/approach–The physical properties of the low-temperature-resistant CR and NRwere tested by low-temperature stretching,dynamic mechanical analysis,differential scanning calorimetryand thermogravimetric analysis.Single-valve and single-vehicle tests of type 120 emergency valves werecarried out for emergency diaphragms consisting of NR and CR.Findings–The low-temperature-resistant CR and NR exhibited excellent physical properties.The elasticityand low-temperature resistance of NR were superior to those of CR,whereas the mechanical properties of thetwo rubbers were similar in the temperature range of 0℃–150℃.The NR and CR emergency diaphragms metthe requirements of the single-valve test.In the low-temperature single-vehicle test,only the low-temperaturesensitivity test of the NR emergency diaphragm met the requirements.Originality/value–The innovation of this study is that it provides valuable data and experience for futuredevelopment of type 120 valve rubber diaphragms.展开更多
The available test methods for optimal moisture content of cold recycled mixture(CRM)as well as its bulk specific gravity,and theoretical maximum relative density were analyzed in this work.Some test improvements were...The available test methods for optimal moisture content of cold recycled mixture(CRM)as well as its bulk specific gravity,and theoretical maximum relative density were analyzed in this work.Some test improvements were suggested to improve test control of the CRM road performance based on the discovered flaws.Besides,the properties of reclaimed asphalt pavement(RAP),including the content of old asphalt,penetration index,passing rate of 4.75 mm sieve,and gradation change rate after extraction,were examined.The effects of RAP characteristics on splitting tensile strength,water stability,the high-and low-temperature performance of emulsified asphalt CRM were studied.The results show that the optimum moisture content of CRM should be determined when the compaction work matches the specimen’s molding work.Among the analyzed methods of bulk specific gravity assessment,the dry-surface and CoreLok methods provide more robust and accurate results than the wax-sealing method,while the dry-surface method is the most cost-efficient.The modified theoretical maximum relative density test method is proposed,which can reduce the systematic error of the vacuum test method.The following RAP-CRM trends can be observed.The lower the content of old asphalt and the smaller the change rate of gradation,the smaller the voids and the better the water stability of CRM.The greater the penetration of old asphalt,the higher the fracture work and low-temperature splitting strength.The greater the penetration,the higher the passing rate of 4.75 mm sieve after extraction,and the worse the high-temperature performance of CRM.展开更多
Rectifying circuit,as a crucial component for converting alternating current into direct current,plays a pivotal role in energy harvesting microsystems.Traditional silicon-based or germanium-based rectifier diodes hin...Rectifying circuit,as a crucial component for converting alternating current into direct current,plays a pivotal role in energy harvesting microsystems.Traditional silicon-based or germanium-based rectifier diodes hinder system integration due to their specific manufacturing processes.Conversely,metal oxide diodes,with their simple fabrication techniques,offer advantages for system integration.The oxygen vacancy defect of oxide semiconductor will greatly affect the electrical performance of the device,so the performance of the diode can be effectively controlled by adjusting the oxygen vacancy concentration.This study centers on optimizing the performance of diodes by modulating the oxygen vacancy concentration within InGaZnO films through control of oxygen flows during the sputtering process.Experimental results demonstrate that the diode exhibits a forward current density of 43.82 A·cm^(−2),with a rectification ratio of 6.94×10^(4),efficiently rectifying input sine signals with 1 kHz frequency and 5 V magnitude.These results demonstrate its potential in energy conversion and management.By adjusting the oxygen vacancy,a methodology is provided for optimizing the performance of rectifying diodes.展开更多
The department of Tillabéri is primarily affected by climatic phenomena, impacting crop yields, growing cycles, and consequently, the economic outcomes of agricultural operations. The objective of this study is t...The department of Tillabéri is primarily affected by climatic phenomena, impacting crop yields, growing cycles, and consequently, the economic outcomes of agricultural operations. The objective of this study is to analyze these impacts of climate disruption on the economic performance of farms. The methodology adopted for this study combined documentary research with field surveys conducted on a sample of 250 randomly selected farmers. The analytical methods used mainly consisted of linear regression, profitability calculations, and linear programming. The findings indicate that all productions across different crops have experienced a decrease over the past 30 years. For instance, the production of millet, sorghum, and cowpea, which were respectively 812 kg/ha, 260 kg/ha, and 100 kg/ha between the last 30 and 20 years, has now dropped to 412 kg/ha, 106 kg/ha, and 46 kg/ha respectively. A negative and significant effect on agricultural net margin was observed due to variables such as flooding, drought, pest invasion in rice fields, and temperature changes. Smallholder farms show a relatively low margin (46%) to cover their fixed costs, which may indicate a risk if fixed expenses are high. Furthermore, the analysis results from linear programming reveal that farmers could achieve an additional net profit per hectare of 116,861 FCFA, 217201.5 FCFA, and 291988.2 FCFA respectively for small, medium, and large producers by managing variable costs and health-related expenses for households.展开更多
This study was designed to determine factors that influence market performance of avocado fruits among smallholder farmers in Mbeya and Songwe regions. A cross section research design entailing 209 farmers from five (...This study was designed to determine factors that influence market performance of avocado fruits among smallholder farmers in Mbeya and Songwe regions. A cross section research design entailing 209 farmers from five (5) districts of two (2) regions and 15 key informants;5 local service providers (LSP), 5 traders/brokers and 5 district extension officers (DEO) were involved in the study. Random selection procedures were used to select avocado producers and purposive selection procedures were used to select key informants. The study employed survey questionnaires to collect data from avocado farmers and structured interview to collect data from key informants. Collected data were analyzed with an aid of descriptive statistics and linear regression model was used to determine significant factors that determine market prices of avocado fruits among smallholder farmers. The demographic characteristics of avocado farmers showed that;61.2% of farmers had age between 36 to 59 years old, 84.7% were married, 74.6% had primary education level, average number of 5 members of the family, average 4.3 acres of owned land and 1.8 acres planted with avocado. Moreover, findings showed that 90.9% grew improved avocado varieties. Farm gate (88.5%) was the major market outlet chosen by avocado farmers. Local merchants and processors were the major buyers of the produced avocado. Results from linear regression analysis showed that variety grown (P P P P < 0.05) were factors that statistically influenced market prices for avocado fruits. The study concluded that despite the remarkable contributions to livelihood of the farmers yet, it is highly fragile on market prices. Therefore, the study recommends the need to establish market systems that will govern avocado fruits marketing for sustainability of the sub-sector.展开更多
NOx sensors, as a core component of diesel engine exhaust treatment system, play an important role in exhaust emission control, which can accurately and quickly detect the NOx and O2 concentration. It has become a nec...NOx sensors, as a core component of diesel engine exhaust treatment system, play an important role in exhaust emission control, which can accurately and quickly detect the NOx and O2 concentration. It has become a necessary option for the detection of existing exhaust emission standards. At present, there is limited and scattered information on knowledge and test methods of NOx sensors, the research of NOx sensors has become a challenging research topic at home and abroad. Based on these requirements, the article systematically integrates the knowledge of principle and testing methods. First of all, through introducing functional description of NOx sensors and the basic principle of NOx sensors, the relevant scholars can have an overall understanding of the product and master the operation mode of products. Secondly, the current status of performance test bench and methods of NOx sensors were described, which can contribute to having a clear understanding of the development process. After that, a new structure of NOx sensors test bench was purposed, which contains six major units including standard gas source, gas mixing unit, analyzer measurement unit, sensor measurement unit, data processing and display unit, exhaust gas treatment unit. And the test bench was validated. The experimental results show that the test bench has the advantages of high-repeatability, high reliability and low cost. And it can realize automatic detection of multiple target values, which is worthy further promotion. Thereby, the article can contribute to the development of its technology indirectly.展开更多
Background: The study’s primary research suggests the relationship between high-school international students in China’s sleep quality and learning efficiency which is academic performance. Considering the effect of...Background: The study’s primary research suggests the relationship between high-school international students in China’s sleep quality and learning efficiency which is academic performance. Considering the effect of Chinese traditional cultural background, this study mainly investigates Chinese international high school students’ sleeping quality and patterns through the Pittsburgh Sleep Quality Index. Methods: A sample of 249 Chinese high school students in the Pearl River Region completed the questionnaire about their sleep quality using PSQI, their academic performance, and socio-demographic factors one month before the final exam in July 2023. Results: None of the students have good sleep quality, according to the PSQI;40.8% of students have poor sleep quality, and 59.2% have significant sleep disturbance. The results of ordinal logistic regression show that good sleep quality is positively associated with good academic performance. Conclusion: Our findings highlight the association between sleep and academic performance on the unique sleep patterns of Chinese international high school students, who often follow very different sleep patterns from other conventional students enrolled in the regular curriculum. High school students suffer from severe sleep deprivation and poor sleep quality. Under great academic stress, Chinese high school students should know the importance of sleep, balance sleep, and study.展开更多
This study was conducted at Fafan Research Center, Golajo research site to evaluate the effect of Moringa stenopetala and pigeon pea leaf supplementation on growth performance of short-eared Somali goat breed. A total...This study was conducted at Fafan Research Center, Golajo research site to evaluate the effect of Moringa stenopetala and pigeon pea leaf supplementation on growth performance of short-eared Somali goat breed. A total of fifteen yearling indigenous short-eared Somali goat breeds with an initial weight of 15.2 ± 0.30 kg were assigned to three treatment groups using completely randomized design. Pigeon pea (Pp) and Moringa stenopetala (MS) feeds were formulated using 0%, 5%, and 10% inclusion levels of MSLM and PPLM as experimental diets, respectively. The feed of the experiment was prepared in two levels (2 kg of Moringa stenopetala and 2 kg of pigeon pea) and was supplemented to experimental animals in treatments one and two, respectively. The average e initial body weight of selected male goats was 18.82 ± 0.37, 18.8 ± 0.37 and 17.8 ± 0.37 kg under treatment groups T1, T2 and control respectively. Data was analyzed using general linear model (GLM) procedure of SAS computer package Version 9.0 (SAS, 2002). The final weights gain (FWG) of goats on T1 and T2 of experimental group was significantly (P 0.05) the final weight gain of goat supplemented on Moringa stenopetala (T1) and pigeon pea levels (T2). The mean average weight gains (AWG) obtained from the supplemented group in this study were 7.50 ± 0.37 and 7.82 ± 0.37 kg for T1 and T2, whereas mean weight gains for un-supplemented goats were found to be 6.26 ± 0.37 kg. Feeding of dried Moringa stenopetala and pigeon pea leaves mixture improved body weights and average daily body weight gain without affecting feed intake and overall health of Somali goat breed. As Moringa stenopetala and pigeon pea leaves are rich nitrogen/protein source, they can be used effectively as substitute for conventional concentrate in the diet of growing goats at small holder farmer’s level where they can be grown in abundance. Therefore, for higher quality of forage and higher total DM yield for animal feeding, moringa should be harvested at wider harvesting intervals of at least 6th- to 8th-week intervals. Similarly, for pigeon peas, 4- to 6-week harvesting interval can result in optimum forage as well as feed quality and resulted in better growth performances for Somali short-eared goat breeds.展开更多
Abscisic acid(ABA)plays a key role in promoting the growth and development of plants,as well as mediating the responses of plants to adverse environmental conditions.Here,we measured the photosynthetic capacity of wil...Abscisic acid(ABA)plays a key role in promoting the growth and development of plants,as well as mediating the responses of plants to adverse environmental conditions.Here,we measured the photosynthetic capacity of wild-type RR,mutant sitiens(sit),and ABA-pretreated sit tomato seedlings following exposure to low-temperature(LT)stress.We found that the net photosynthetic rate,intercellular carbon dioxide concentration,transpiration rate,and stomatal conductance of sit seedlings were lower than those of RR seedlings under LT stress.The chloroplast width,area,and number of osmiophilic granules were significantly larger in sit seedlings than in RR seedlings,while the chloroplast length/width ratio was significantly lower in sit seedlings than in RR seedlings.The photochemical activity of sit seedlings was lower,and the expression of photosynthesis-related genes in sit seedlings was altered following exposure to LT stress.ABA pretreatment significantly alleviated the above phenomenon.We also conducted an RNA sequencing analysis and characterized the expression patterns of genes in tomato seedlings following exposure to LT stress.We constructed 15 cDNA libraries and identified several differentially expressed genes involved in photosynthesis,plant hormone signaling transduction,and primary and secondary metabolism.Additional analyses of genes encoding transcription factors and proteins involved in photosynthesis-related processes showed pronounced changes in expression under LT stress.Luciferase reporter assay and electrophoretic mobility shift assay revealed that WRKY22 regulates the expression of PsbA.The PSII of WRKY22 and PsbA-silenced plants was inhibited.Our findings indicate that ABA plays a role in regulating the process of photosynthesis and protecting PSII in tomato under LT stress through the WRKY22-PsbA complex.展开更多
The occurrence of tetragonal to monoclinic phase(t→m)transformation in zirconia ceramics under humid ambient conditions induces the low-temperature degradation(LTD).Such t→m transformation could be suppressed by gra...The occurrence of tetragonal to monoclinic phase(t→m)transformation in zirconia ceramics under humid ambient conditions induces the low-temperature degradation(LTD).Such t→m transformation could be suppressed by grain size refinement or/and doping small amounts of alumina.Fine-grained dense 3mol%yttria-doped tetragonal zirconia polycrystal(3Y-TZP)ceramics were prepared by pressureless sintering a zirconia powder doped with 0.25wt%alumina.The LTD behaviors of as-prepared 3Y-TZP ceramics were evaluated by accelerated aging at 134℃in water.The samples sintered at 1300℃for 2 h achieve the relative density higher than 99.9%with the average grain size of 147 nm.The 3Y-TZP ceramic exhibits excellent LTD resistance that no t→m transformation takes place after 125 h accelerated aging.Large amounts of defects were observed inside grains evidenced by the high-resolution transmission electron microscopic(HRTEM)analysis.It is proposed that the presence of defects enhances the sintering kinetics and favors the present low-temperature densification.Possible reasons for defects formation were discussed and the mechanical properties of the 3Y-TZP ceramic were reported as well.展开更多
Sweet potato is one of the most important crops in Côte d’Ivoire. However, some constraints related to climate change limit its production. This study evaluated the agronomic and technological performances of ei...Sweet potato is one of the most important crops in Côte d’Ivoire. However, some constraints related to climate change limit its production. This study evaluated the agronomic and technological performances of eight varieties of orange-fleshed of sweet potato (Ipomoea batatas (L.) to identify the most promising ones. The results show three groups of varieties with different agronomic performances. Group 1 composed of Irene and Vita is characterized by low production of small and large tuberous roots, low number of productive plants and low yield. Group 2 consisting mainly of Kabode is characterized by high production and weight of large tuberous roots as well as high yield. Group 3, composed of Tacha-2 Ininda, Ejumula Gloria, TIB-440060, CIP-199062-1, Bela bela is characterized by high production of small and large tuberous roots, high number of productive plants and average yield. The TIB-440060 variety has a recovery rate of 100%. The Irene, Kabode, Vita, Kabode varieties were resistant to viral and fungal diseases. In terms of technological quality, the TIB-440060 and CIP-199062-1 varieties have the best organoleptic qualities. Given the agronomic performances of the Kabode, TIB-440060 and CIP-199062-1 varieties, could be selected as the elites varieties and distributed to producers.展开更多
The article discusses the use of pulse-width modulation signals to generate low-temperature atmospheric plasma in an inert gas environment.The results of studies of the energy consumption of a low-temperature plasma g...The article discusses the use of pulse-width modulation signals to generate low-temperature atmospheric plasma in an inert gas environment.The results of studies of the energy consumption of a low-temperature plasma generation system depending on the duty rate,as well as the pulse repetition rate,are presented.The operating modes of the system have been established,in which a minimum of energy consumption is achieved.The issues of evaluating the interaction of plasma with objects based on the analysis of changes in signal parameters in the high-voltage circuit of the generator are also considered.展开更多
Zinc oxide(ZnO),as a broadband gap semiconductor material,exhibits unique physical and chemical properties that make it highly suitable for optoelectronics,piezoelectric devices,and gas-sensitive sensors,showing signi...Zinc oxide(ZnO),as a broadband gap semiconductor material,exhibits unique physical and chemical properties that make it highly suitable for optoelectronics,piezoelectric devices,and gas-sensitive sensors,showing significant potential for various applications.This paper focuses on the regulation and application of ZnO-based p-n junctions and piezoelectric devices.It discusses in detail the preparation of ZnO materials,the construction of p-n junctions,the optimization of piezoelectric device performance,and its application in various fields.By employing different preparation methods and strategies,high-quality ZnO thin films can be grown,and effective control of p-type conductivity achieved.This study provides both a theoretical foundation and technical support for controlling the performance of ZnO-based piezoelectric devices,as well as paving new pathways for the broader application of ZnO materials.展开更多
As an evaluation index,the natural frequency has the advantages of easy acquisition and quantitative evaluation.In this paper,the natural frequency is used to evaluate the performance of external cable reinforced brid...As an evaluation index,the natural frequency has the advantages of easy acquisition and quantitative evaluation.In this paper,the natural frequency is used to evaluate the performance of external cable reinforced bridges.Numerical examples show that compared with the natural frequencies of first-order modes,the natural frequencies of higher-order modes are more sensitive and can reflect the damage situation and external cable reinforcement effect of T-beam bridges.For damaged bridges,as the damage to the T-beam increases,the natural frequency value of the bridge gradually decreases.When the degree of local damage to the beam reaches 60%,the amplitude of natural frequency change exceeds 10%for the first time.The natural frequencies of the firstorder vibration mode and higher-order vibration mode can be selected as indexes for different degrees of the damaged T-beam bridges.For damaged bridges reinforced with external cables,the traditional natural frequency of the first-order vibration mode cannot be used as the index,which is insensitive to changes in prestress of the external cable.Some natural frequencies of higher-order vibration modes can be selected as indexes,which can reflect the reinforcement effect of externally prestressed damaged T-beam bridges,and its numerical value increases with the increase of external prestressed cable force.展开更多
In this work,an oscillating-body wave energy converter(OBWEC)with a hydraulic power take-off(PTO)system named“Dolphin 1”is designed,in which the hydraulic PTO system is equivalent to a transfer station and plays a c...In this work,an oscillating-body wave energy converter(OBWEC)with a hydraulic power take-off(PTO)system named“Dolphin 1”is designed,in which the hydraulic PTO system is equivalent to a transfer station and plays a crucial role in ensuring the stability of the electrical energy output and the efficiency of the overall system.A corresponding mathematical model for the hydraulic PTO system has been established,the factors that influence its performance have been studied,and an algorithm for solving the optimal working pressure has been derived in this paper.Moreover,a PID control method to enable the hydraulic PTO system to automatically achieve optimal performance under different wave conditions has been designed.The results indicate that,compared with single-chamber hydraulic cylinders,double-chamber hydraulic cylinders have a wider application range and greater performance;the accumulator can stabilize the output power of the hydraulic PTO system and slightly increase it;excessively large or small hydraulic motor displacement hinders system performance;and each wave condition corresponds to a unique optimal working pressure for the hydraulic PTO system.In addition,the relationship between the optimal working pressure P_(m)and the pressure P_(h)of the wave force acting on the piston satisfies P_(m)^(2)=∫_(t_(1))^(t_(2))P_(h)^(2)dt/(t_(2)-t_(1)).Furthermore,adjusting the hydraulic motor displacement automatically via a PID controller ensures that the actual working pressure of the hydraulic PTO system consistently reaches or approaches its theoretically optimal value under various wave conditions,which is a very effective control method for enhancing the performance of the hydraulic PTO system.展开更多
基金the National Natural Science Foundation of China(Grant No.52072138,21571073,51772115)National Key Research and Development Program of China(Grant No.2018YFE0206900)Hubei Provincial Natural Science Foundation of China(Grant No.2019CFA002)。
文摘Among the alloying-type anodes,elemental Sb possesses the suitable yet safe plateau,simple lithiation pathway,small voltage polarization,high conductivity,and superior cycle stability.However,challenge is that its intrinsic capacity is rather low(660 mAh g^(-1)),<1/6 of silicon.Herein,we propose a seamless integration strategy by merging the voltage and capacity of phosphorus and antimony into a solid solution alloy.Interestingly,the enlistment of P is found greatly enlarge the capacity from 660 to 993 mAh g^(-1) for such Sb_(30)P_(30) solid solution,while maintaining a single and stable discharge plateau(~0.79 V)similar to elemental Sb.Various experimental characterizations including XPS,PDF,Raman,and EDS mapping reveal that in such a material the P and Sb atoms have interacted with each other to form a homogenous solid solution alloy,rather than a simple mixing of the two substances.Thus,the Sb_(30)P_(30) exhibits superior rate performances(807 mAh g^(-1) at 5000 mA g^(-1))and cyclability(821 mAh g^(-1) remained after 300 cycles).Furthermore,such Sb_(60-x)P_(x) alloys can even deliver 621 mAh g^(-1) at30℃,which can be served as the alternative anode materials for high-energy and low-temperature batteries.This unique seamless integration strategy based on solid solution chemistry can be easily leveraged to manipulate the capacity of other electrode materials at similar voltage.
基金Project(2006AA11A151) supported by the National Hi-Tech Research and Development Program of China
文摘Low-temperature performance and high-rate discharge capability of AB5-type non-stoichiometric hydrogen storage are studied. X-ray diffraction(XRD),pressure-composition-temperature(PCT) curves and electrochemical impedance spectroscopy(EIS) are applied to characterize the electrochemical properties of ABx(x=4.8,4.9,5.0,5.1,5.2) alloys. The results show that the non-stoichiometric alloys exhibit better electrochemical properties compared with that of the AB5 alloy.
基金supported by the Natural Science Foundation of Xiamen, China (3502Z202372036)the National Natural Science Foundation of China (52372191, 52073286 (to CZ Lu), 22275185 (to CZ Lu))+4 种基金the Scientific Research Funds of Huaqiao University (20221XD027, 20221XD045)the Xiamen Institute of Rare Earth Materials Haixi Institutes (XMIREM)the Autonomously Deployment Project (2023GG01 (to CZ Lu))the Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China (2021ZZ115 (to CZ Lu))the China Postdoctoral Science Foundation (2022TQ0282)。
文摘Achieving an in-depth understanding of the nexus between temperature and phase transitions is paramount for advancing the electrochemical efficiency of aqueous zinc ion batteries.Yet,the intricacies of electrochemical interactions,particularly those associated with the structural evolution over extended periods,remain enigmatic.In this research,we leverage V_(2)O_(5) as an initial structural model of crystals to demystify the kinetics of electrode reactions and the decay mechanism of global electrochemical degradation by meticulously controlling the crystal defects via applying different mechanical grounding intensities.It is noted that the grounding V_(2)O_(5)(GVO)can exhibit a stable crystal structure that suppresses the dissolution/shuttling of vanadium and mitigates Zn anodes by-products caused by electrochemical processes.Thus,the GVO is utilized as the cathode material,achieving excellent Zn storage capacity at both room temperature and low temperatures,e.g.,380 and 246 mA h g^(−1) at room temperature and−20℃,respectively.Remarkably,the GVO cathode retains a specific capacity of 160 mA h g^(−1) with a capacity retention rate of 99%after 1500 cycles at−20℃ and 1 A g^(−1).This work provides a novel insight into the electrochemical crosstalk behavior of aqueous zinc-ion batteries(AZIBs)in a wide range of temperatures.
基金Guangdong High-level Innovation Institute Project,Grant/Award Number:2021 B0909050001National Natural Science Foundation(NNSF)of China,Grant/Award Number:22309162GRINM Young Scholar Funding Project,National Natural Science Foundation of China,Grant/Award Number:12104024。
文摘Sodium-ion batteries (NIBs) have become an ideal alternative to lithium-ion batteries in the field of electrochemical energy storage due to their abundant raw materials and cost-effectiveness. With the progress of human society, the requirements for energy storage systems in extreme environments, such as deep-sea exploration, aerospace missions, and tunnel operations, have become more stringent. The comprehensive performance of NIBs at low temperatures (LTs) has also become an important consideration. Under LT conditions, challenges such as increased viscosity of electrolyte, abnormal growth of solid electrolyte interface, and poor contact between collector and electrode materials emerge. The aforementioned issues hinder the diffusion kinetics of sodium ions (Na^(+)) at the electrode/electrolyte interface and cause rapid degradation of battery performance. Consequently, the optimization of electrolyte composition and cathode/anode materials becomes an effective approach to improve LT performance. This review discusses the conduction behavior and limiting factors of Na^(+) in both solid electrodes and liquid electrolytes at LT. Furthermore, it systematically reviews the recent research progress of LT NIBs from three aspects: cathode materials, anode materials, and electrolyte components. This review aims to provide a valuable reference for developing high-performance LT NIBs.
基金financially supported by the Guangzhou Basic and Applied Basic Research Foundation,China(No.303523)。
文摘CsPbX_(3)-based(X=I,Br,Cl)inorganic perovskite solar cells(PSCs)prepared by low-temperature process have attracted much attention because of their low cost and excellent thermal stability.However,the high trap state density and serious charge recombination between low-temperature processed TiO_(2)film and inorganic perovskite layer interface seriously restrict the performance of all-inorganic PSCs.Here a thin polyethylene oxide(PEO)layer is employed to modify TiO_(2)film to passivate traps and promote carrier collection.The impacts of PEO layer on microstructure and photoelectric characteristics of TiO_(2)film and related devices are systematically studied.Characterization results suggest that PEO modification can reduce the surface roughness of TiO_(2)film,decrease its average surface potential,and passivate trap states.At optimal conditions,the champion efficiency of CsPbI_(2)Br PSCs with PEO-modified TiO_(2)(PEO-PSCs)has been improved to 11.24%from 9.03%of reference PSCs.Moreover,the hysteresis behavior and charge recombination have been suppressed in PEO-PSCs.
基金funded by the Science and Technology Research and Development Plan of the China State Railway Group Company Limited(No.N2023J053).
文摘Purpose–The type 120 emergency valve is an essential braking component of railway freight trains,butcorresponding diaphragms consisting of natural rubber(NR)and chloroprene rubber(CR)exhibit insufficientaging resistance and low-temperature resistance,respectively.In order to develop type 120 emergency valverubber diaphragms with long-life and high-performance,low-temperatureresistant CR and NR were processed.Design/methodology/approach–The physical properties of the low-temperature-resistant CR and NRwere tested by low-temperature stretching,dynamic mechanical analysis,differential scanning calorimetryand thermogravimetric analysis.Single-valve and single-vehicle tests of type 120 emergency valves werecarried out for emergency diaphragms consisting of NR and CR.Findings–The low-temperature-resistant CR and NR exhibited excellent physical properties.The elasticityand low-temperature resistance of NR were superior to those of CR,whereas the mechanical properties of thetwo rubbers were similar in the temperature range of 0℃–150℃.The NR and CR emergency diaphragms metthe requirements of the single-valve test.In the low-temperature single-vehicle test,only the low-temperaturesensitivity test of the NR emergency diaphragm met the requirements.Originality/value–The innovation of this study is that it provides valuable data and experience for futuredevelopment of type 120 valve rubber diaphragms.
文摘The available test methods for optimal moisture content of cold recycled mixture(CRM)as well as its bulk specific gravity,and theoretical maximum relative density were analyzed in this work.Some test improvements were suggested to improve test control of the CRM road performance based on the discovered flaws.Besides,the properties of reclaimed asphalt pavement(RAP),including the content of old asphalt,penetration index,passing rate of 4.75 mm sieve,and gradation change rate after extraction,were examined.The effects of RAP characteristics on splitting tensile strength,water stability,the high-and low-temperature performance of emulsified asphalt CRM were studied.The results show that the optimum moisture content of CRM should be determined when the compaction work matches the specimen’s molding work.Among the analyzed methods of bulk specific gravity assessment,the dry-surface and CoreLok methods provide more robust and accurate results than the wax-sealing method,while the dry-surface method is the most cost-efficient.The modified theoretical maximum relative density test method is proposed,which can reduce the systematic error of the vacuum test method.The following RAP-CRM trends can be observed.The lower the content of old asphalt and the smaller the change rate of gradation,the smaller the voids and the better the water stability of CRM.The greater the penetration of old asphalt,the higher the fracture work and low-temperature splitting strength.The greater the penetration,the higher the passing rate of 4.75 mm sieve after extraction,and the worse the high-temperature performance of CRM.
文摘Rectifying circuit,as a crucial component for converting alternating current into direct current,plays a pivotal role in energy harvesting microsystems.Traditional silicon-based or germanium-based rectifier diodes hinder system integration due to their specific manufacturing processes.Conversely,metal oxide diodes,with their simple fabrication techniques,offer advantages for system integration.The oxygen vacancy defect of oxide semiconductor will greatly affect the electrical performance of the device,so the performance of the diode can be effectively controlled by adjusting the oxygen vacancy concentration.This study centers on optimizing the performance of diodes by modulating the oxygen vacancy concentration within InGaZnO films through control of oxygen flows during the sputtering process.Experimental results demonstrate that the diode exhibits a forward current density of 43.82 A·cm^(−2),with a rectification ratio of 6.94×10^(4),efficiently rectifying input sine signals with 1 kHz frequency and 5 V magnitude.These results demonstrate its potential in energy conversion and management.By adjusting the oxygen vacancy,a methodology is provided for optimizing the performance of rectifying diodes.
文摘The department of Tillabéri is primarily affected by climatic phenomena, impacting crop yields, growing cycles, and consequently, the economic outcomes of agricultural operations. The objective of this study is to analyze these impacts of climate disruption on the economic performance of farms. The methodology adopted for this study combined documentary research with field surveys conducted on a sample of 250 randomly selected farmers. The analytical methods used mainly consisted of linear regression, profitability calculations, and linear programming. The findings indicate that all productions across different crops have experienced a decrease over the past 30 years. For instance, the production of millet, sorghum, and cowpea, which were respectively 812 kg/ha, 260 kg/ha, and 100 kg/ha between the last 30 and 20 years, has now dropped to 412 kg/ha, 106 kg/ha, and 46 kg/ha respectively. A negative and significant effect on agricultural net margin was observed due to variables such as flooding, drought, pest invasion in rice fields, and temperature changes. Smallholder farms show a relatively low margin (46%) to cover their fixed costs, which may indicate a risk if fixed expenses are high. Furthermore, the analysis results from linear programming reveal that farmers could achieve an additional net profit per hectare of 116,861 FCFA, 217201.5 FCFA, and 291988.2 FCFA respectively for small, medium, and large producers by managing variable costs and health-related expenses for households.
文摘This study was designed to determine factors that influence market performance of avocado fruits among smallholder farmers in Mbeya and Songwe regions. A cross section research design entailing 209 farmers from five (5) districts of two (2) regions and 15 key informants;5 local service providers (LSP), 5 traders/brokers and 5 district extension officers (DEO) were involved in the study. Random selection procedures were used to select avocado producers and purposive selection procedures were used to select key informants. The study employed survey questionnaires to collect data from avocado farmers and structured interview to collect data from key informants. Collected data were analyzed with an aid of descriptive statistics and linear regression model was used to determine significant factors that determine market prices of avocado fruits among smallholder farmers. The demographic characteristics of avocado farmers showed that;61.2% of farmers had age between 36 to 59 years old, 84.7% were married, 74.6% had primary education level, average number of 5 members of the family, average 4.3 acres of owned land and 1.8 acres planted with avocado. Moreover, findings showed that 90.9% grew improved avocado varieties. Farm gate (88.5%) was the major market outlet chosen by avocado farmers. Local merchants and processors were the major buyers of the produced avocado. Results from linear regression analysis showed that variety grown (P P P P < 0.05) were factors that statistically influenced market prices for avocado fruits. The study concluded that despite the remarkable contributions to livelihood of the farmers yet, it is highly fragile on market prices. Therefore, the study recommends the need to establish market systems that will govern avocado fruits marketing for sustainability of the sub-sector.
文摘NOx sensors, as a core component of diesel engine exhaust treatment system, play an important role in exhaust emission control, which can accurately and quickly detect the NOx and O2 concentration. It has become a necessary option for the detection of existing exhaust emission standards. At present, there is limited and scattered information on knowledge and test methods of NOx sensors, the research of NOx sensors has become a challenging research topic at home and abroad. Based on these requirements, the article systematically integrates the knowledge of principle and testing methods. First of all, through introducing functional description of NOx sensors and the basic principle of NOx sensors, the relevant scholars can have an overall understanding of the product and master the operation mode of products. Secondly, the current status of performance test bench and methods of NOx sensors were described, which can contribute to having a clear understanding of the development process. After that, a new structure of NOx sensors test bench was purposed, which contains six major units including standard gas source, gas mixing unit, analyzer measurement unit, sensor measurement unit, data processing and display unit, exhaust gas treatment unit. And the test bench was validated. The experimental results show that the test bench has the advantages of high-repeatability, high reliability and low cost. And it can realize automatic detection of multiple target values, which is worthy further promotion. Thereby, the article can contribute to the development of its technology indirectly.
文摘Background: The study’s primary research suggests the relationship between high-school international students in China’s sleep quality and learning efficiency which is academic performance. Considering the effect of Chinese traditional cultural background, this study mainly investigates Chinese international high school students’ sleeping quality and patterns through the Pittsburgh Sleep Quality Index. Methods: A sample of 249 Chinese high school students in the Pearl River Region completed the questionnaire about their sleep quality using PSQI, their academic performance, and socio-demographic factors one month before the final exam in July 2023. Results: None of the students have good sleep quality, according to the PSQI;40.8% of students have poor sleep quality, and 59.2% have significant sleep disturbance. The results of ordinal logistic regression show that good sleep quality is positively associated with good academic performance. Conclusion: Our findings highlight the association between sleep and academic performance on the unique sleep patterns of Chinese international high school students, who often follow very different sleep patterns from other conventional students enrolled in the regular curriculum. High school students suffer from severe sleep deprivation and poor sleep quality. Under great academic stress, Chinese high school students should know the importance of sleep, balance sleep, and study.
文摘This study was conducted at Fafan Research Center, Golajo research site to evaluate the effect of Moringa stenopetala and pigeon pea leaf supplementation on growth performance of short-eared Somali goat breed. A total of fifteen yearling indigenous short-eared Somali goat breeds with an initial weight of 15.2 ± 0.30 kg were assigned to three treatment groups using completely randomized design. Pigeon pea (Pp) and Moringa stenopetala (MS) feeds were formulated using 0%, 5%, and 10% inclusion levels of MSLM and PPLM as experimental diets, respectively. The feed of the experiment was prepared in two levels (2 kg of Moringa stenopetala and 2 kg of pigeon pea) and was supplemented to experimental animals in treatments one and two, respectively. The average e initial body weight of selected male goats was 18.82 ± 0.37, 18.8 ± 0.37 and 17.8 ± 0.37 kg under treatment groups T1, T2 and control respectively. Data was analyzed using general linear model (GLM) procedure of SAS computer package Version 9.0 (SAS, 2002). The final weights gain (FWG) of goats on T1 and T2 of experimental group was significantly (P 0.05) the final weight gain of goat supplemented on Moringa stenopetala (T1) and pigeon pea levels (T2). The mean average weight gains (AWG) obtained from the supplemented group in this study were 7.50 ± 0.37 and 7.82 ± 0.37 kg for T1 and T2, whereas mean weight gains for un-supplemented goats were found to be 6.26 ± 0.37 kg. Feeding of dried Moringa stenopetala and pigeon pea leaves mixture improved body weights and average daily body weight gain without affecting feed intake and overall health of Somali goat breed. As Moringa stenopetala and pigeon pea leaves are rich nitrogen/protein source, they can be used effectively as substitute for conventional concentrate in the diet of growing goats at small holder farmer’s level where they can be grown in abundance. Therefore, for higher quality of forage and higher total DM yield for animal feeding, moringa should be harvested at wider harvesting intervals of at least 6th- to 8th-week intervals. Similarly, for pigeon peas, 4- to 6-week harvesting interval can result in optimum forage as well as feed quality and resulted in better growth performances for Somali short-eared goat breeds.
基金supported by the National Natural Science Foundation of China(32272791 and 32072651)the earmarked fund for CARS(CARS-23)+1 种基金the Joint Fund for Innovation Enhancement of Liaoning Province,China(2021-NLTS-11-01)the support program for Young and Middle-aged Scientific and Technological Innovation Talents,China(RC210293)。
文摘Abscisic acid(ABA)plays a key role in promoting the growth and development of plants,as well as mediating the responses of plants to adverse environmental conditions.Here,we measured the photosynthetic capacity of wild-type RR,mutant sitiens(sit),and ABA-pretreated sit tomato seedlings following exposure to low-temperature(LT)stress.We found that the net photosynthetic rate,intercellular carbon dioxide concentration,transpiration rate,and stomatal conductance of sit seedlings were lower than those of RR seedlings under LT stress.The chloroplast width,area,and number of osmiophilic granules were significantly larger in sit seedlings than in RR seedlings,while the chloroplast length/width ratio was significantly lower in sit seedlings than in RR seedlings.The photochemical activity of sit seedlings was lower,and the expression of photosynthesis-related genes in sit seedlings was altered following exposure to LT stress.ABA pretreatment significantly alleviated the above phenomenon.We also conducted an RNA sequencing analysis and characterized the expression patterns of genes in tomato seedlings following exposure to LT stress.We constructed 15 cDNA libraries and identified several differentially expressed genes involved in photosynthesis,plant hormone signaling transduction,and primary and secondary metabolism.Additional analyses of genes encoding transcription factors and proteins involved in photosynthesis-related processes showed pronounced changes in expression under LT stress.Luciferase reporter assay and electrophoretic mobility shift assay revealed that WRKY22 regulates the expression of PsbA.The PSII of WRKY22 and PsbA-silenced plants was inhibited.Our findings indicate that ABA plays a role in regulating the process of photosynthesis and protecting PSII in tomato under LT stress through the WRKY22-PsbA complex.
基金financially supported by the Foundation of Hubei Province Key Laboratory of Green Materials for Light Industry,Hubei University of Technology。
文摘The occurrence of tetragonal to monoclinic phase(t→m)transformation in zirconia ceramics under humid ambient conditions induces the low-temperature degradation(LTD).Such t→m transformation could be suppressed by grain size refinement or/and doping small amounts of alumina.Fine-grained dense 3mol%yttria-doped tetragonal zirconia polycrystal(3Y-TZP)ceramics were prepared by pressureless sintering a zirconia powder doped with 0.25wt%alumina.The LTD behaviors of as-prepared 3Y-TZP ceramics were evaluated by accelerated aging at 134℃in water.The samples sintered at 1300℃for 2 h achieve the relative density higher than 99.9%with the average grain size of 147 nm.The 3Y-TZP ceramic exhibits excellent LTD resistance that no t→m transformation takes place after 125 h accelerated aging.Large amounts of defects were observed inside grains evidenced by the high-resolution transmission electron microscopic(HRTEM)analysis.It is proposed that the presence of defects enhances the sintering kinetics and favors the present low-temperature densification.Possible reasons for defects formation were discussed and the mechanical properties of the 3Y-TZP ceramic were reported as well.
文摘Sweet potato is one of the most important crops in Côte d’Ivoire. However, some constraints related to climate change limit its production. This study evaluated the agronomic and technological performances of eight varieties of orange-fleshed of sweet potato (Ipomoea batatas (L.) to identify the most promising ones. The results show three groups of varieties with different agronomic performances. Group 1 composed of Irene and Vita is characterized by low production of small and large tuberous roots, low number of productive plants and low yield. Group 2 consisting mainly of Kabode is characterized by high production and weight of large tuberous roots as well as high yield. Group 3, composed of Tacha-2 Ininda, Ejumula Gloria, TIB-440060, CIP-199062-1, Bela bela is characterized by high production of small and large tuberous roots, high number of productive plants and average yield. The TIB-440060 variety has a recovery rate of 100%. The Irene, Kabode, Vita, Kabode varieties were resistant to viral and fungal diseases. In terms of technological quality, the TIB-440060 and CIP-199062-1 varieties have the best organoleptic qualities. Given the agronomic performances of the Kabode, TIB-440060 and CIP-199062-1 varieties, could be selected as the elites varieties and distributed to producers.
文摘The article discusses the use of pulse-width modulation signals to generate low-temperature atmospheric plasma in an inert gas environment.The results of studies of the energy consumption of a low-temperature plasma generation system depending on the duty rate,as well as the pulse repetition rate,are presented.The operating modes of the system have been established,in which a minimum of energy consumption is achieved.The issues of evaluating the interaction of plasma with objects based on the analysis of changes in signal parameters in the high-voltage circuit of the generator are also considered.
基金The Natural Science Foundation of Guangdong Province(Project No.2023A1515012352)。
文摘Zinc oxide(ZnO),as a broadband gap semiconductor material,exhibits unique physical and chemical properties that make it highly suitable for optoelectronics,piezoelectric devices,and gas-sensitive sensors,showing significant potential for various applications.This paper focuses on the regulation and application of ZnO-based p-n junctions and piezoelectric devices.It discusses in detail the preparation of ZnO materials,the construction of p-n junctions,the optimization of piezoelectric device performance,and its application in various fields.By employing different preparation methods and strategies,high-quality ZnO thin films can be grown,and effective control of p-type conductivity achieved.This study provides both a theoretical foundation and technical support for controlling the performance of ZnO-based piezoelectric devices,as well as paving new pathways for the broader application of ZnO materials.
基金supported by Henan Province Science and Technology Research Funding Project(No.222102320129)the Key Research Project of Henan Higher Education Institutions(Grant Nos.22A560004,22A56005).
文摘As an evaluation index,the natural frequency has the advantages of easy acquisition and quantitative evaluation.In this paper,the natural frequency is used to evaluate the performance of external cable reinforced bridges.Numerical examples show that compared with the natural frequencies of first-order modes,the natural frequencies of higher-order modes are more sensitive and can reflect the damage situation and external cable reinforcement effect of T-beam bridges.For damaged bridges,as the damage to the T-beam increases,the natural frequency value of the bridge gradually decreases.When the degree of local damage to the beam reaches 60%,the amplitude of natural frequency change exceeds 10%for the first time.The natural frequencies of the firstorder vibration mode and higher-order vibration mode can be selected as indexes for different degrees of the damaged T-beam bridges.For damaged bridges reinforced with external cables,the traditional natural frequency of the first-order vibration mode cannot be used as the index,which is insensitive to changes in prestress of the external cable.Some natural frequencies of higher-order vibration modes can be selected as indexes,which can reflect the reinforcement effect of externally prestressed damaged T-beam bridges,and its numerical value increases with the increase of external prestressed cable force.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.52071094 and 51979065).
文摘In this work,an oscillating-body wave energy converter(OBWEC)with a hydraulic power take-off(PTO)system named“Dolphin 1”is designed,in which the hydraulic PTO system is equivalent to a transfer station and plays a crucial role in ensuring the stability of the electrical energy output and the efficiency of the overall system.A corresponding mathematical model for the hydraulic PTO system has been established,the factors that influence its performance have been studied,and an algorithm for solving the optimal working pressure has been derived in this paper.Moreover,a PID control method to enable the hydraulic PTO system to automatically achieve optimal performance under different wave conditions has been designed.The results indicate that,compared with single-chamber hydraulic cylinders,double-chamber hydraulic cylinders have a wider application range and greater performance;the accumulator can stabilize the output power of the hydraulic PTO system and slightly increase it;excessively large or small hydraulic motor displacement hinders system performance;and each wave condition corresponds to a unique optimal working pressure for the hydraulic PTO system.In addition,the relationship between the optimal working pressure P_(m)and the pressure P_(h)of the wave force acting on the piston satisfies P_(m)^(2)=∫_(t_(1))^(t_(2))P_(h)^(2)dt/(t_(2)-t_(1)).Furthermore,adjusting the hydraulic motor displacement automatically via a PID controller ensures that the actual working pressure of the hydraulic PTO system consistently reaches or approaches its theoretically optimal value under various wave conditions,which is a very effective control method for enhancing the performance of the hydraulic PTO system.
