In hilly regions,the existence of surface cracks in rock mass induces a potential threat to structural stability.Thus,the present research aims to explore the impact of surface cracks on the loadbearing capacity of st...In hilly regions,the existence of surface cracks in rock mass induces a potential threat to structural stability.Thus,the present research aims to explore the impact of surface cracks on the loadbearing capacity of strip footing placed on the rock mass.By taking into account the various boundary constraints across the surface of crack edges,the study investigates the presence of two categories of surface cracks,namely(1)separated crack,and(2)fine crack.The lower bound limit analysis is employed in conjunction with the finite element method(LBFELA)to conduct the numerical analysis.In order to evaluate rock mass yielding,the power conic programming(PCP)method is utilized to implement the generalized Hoek-Brown(GHB)failure criterion.The stability of the strip footing is analyzed by determining the bearing capacity factor(Nσγ),which is presented in the form of design charts by varying the strength parameters of rock,including the Geological Strength Index(GSI),Hoek-Brown material parameter(mi),Disturbance factor(D),and Normalised Uniaxial Compressive Strength(σci/γB),whereγis the unit weight of rock mass,and B is the width of strip footing.The study also investigates the impact of cracks on strip footings,considering different positions of the crack(LC)and depths of the crack(DC).The results demonstrate that the influence of the fine crack is only noticeable until the LC/B ratio reaches 6.However,for the separated crack,its impact remains significant even when the LC/B ratio exceeds 16.The appearance of fine crack at the edge of the footing results in a decrease in the magnitude Nσγof up to 45%,indicating a substantial reduction in the stability of the footing.The failure patterns are presented and discussed in detail for various cases in this study to examine the effect of surface cracks on the strip footing and to address the extent of the plastic collapse.展开更多
Stripping units take a key role in the neutral particle analyzer(NPA).A renovated gas-stripping unit was constructed for the newly designed E//B NPA.Using H_(2)as the working gas,we measured the gas inlet pressure(P_(...Stripping units take a key role in the neutral particle analyzer(NPA).A renovated gas-stripping unit was constructed for the newly designed E//B NPA.Using H_(2)as the working gas,we measured the gas inlet pressure(P_(0))and vacuum chamber pressure(P_(3)).The pressure distribution inside the gas-stripping room was calculated with Ansys Fluent,using the measured P_(0)and P_(3)as boundary conditions.The stripping efficiency of the stripping unit was then simulated utilizing the Geant4 Monte Carlo code for the H and D particles.The pressure P_(0)=40 Pa,which is one-sixth of what found in the previous design and corresponds to a thickness of 1.27×10^(17)atoms∕cm^(2),was obtained as the optimum working pressure for the upgraded stripping unit.An 50 kV electron cyclotron resonance(ECR)ion source platform was designed and constructed for E//B NPA calibration,and its performance has been measured.Using the ECR ion source platform,we measured the efficiency of the stripping unit through an inverse experiment with proton beams.We compared the current ratios of measurements with and without H_(2)gas to Geant4 simulation results.We found adequate agreement between the overall trends of the experiment and the simulation.The significant deviation for incident energies below 20 keV may result from the scattering effects of low-energy protons,leading to reduced accuracy in single-scattering physics in Geant4 simulations.Applying the scattering corrections observed in the reverse experiments obtains more accurate stripping efficiencies for H and D atoms in the energy range of 20–200 keV and the global efficiency with the maximum values of 95.0%for H atoms and 78.9%for D atoms at 200 keV.展开更多
The complex producing procedures and high energy-consuming limit the large-scale production and application of advanced high-strength steels(AHSSs).In this study,the direct strip casting(DSC)technology with unique sub...The complex producing procedures and high energy-consuming limit the large-scale production and application of advanced high-strength steels(AHSSs).In this study,the direct strip casting(DSC)technology with unique sub-rapid solidification characteristics and cost advantages was applied to the production of low-alloy Si-Mn steel with the help of quenching&partitioning(Q&P)concept to address these issues.Compared this method with the conventional compact strip production(CSP)process,the initial microstructure formed under different solidification conditions and the influence of heat treatment processes on the final mechanical properties were in-vestigated.The results show that the initial structure of the DSC sample is a dual-phase structure composed of fine lath martensite and bainite,while the initial structure of the CSP sample consists of pearlite and ferrite.The volume fraction and carbon content of retained austenite(RA)in DSC samples are usually higher than those in CSP samples after the same Q&P treatment.DSC samples typically demonstrate better comprehensive mechanical properties than the CSP sample.The DSC sample partitioned at 300℃ for 300 s(DSC-Pt300)achieves the best comprehensive mechanical properties,with yield strength(YS)of 1282 MPa,ultimate tensile strength(UTS)of 1501 MPa,total elongation(TE)of 21.5%,and product of strength and elongation(PSE)as high as 32.3 GPa·%.These results indicate that the excellent mechanical properties in low-alloy Si-Mn steel can be obtained through a simple process(DSC-Q&P),which also demonstrates the superiority of DSC technology in manufacturing AHSSs.展开更多
Traditional transgenic detection methods require high test conditions and struggle to be both sensitive and efficient.In this study,a one-tube dual recombinase polymerase amplification(RPA)reaction system for CP4-EPSP...Traditional transgenic detection methods require high test conditions and struggle to be both sensitive and efficient.In this study,a one-tube dual recombinase polymerase amplification(RPA)reaction system for CP4-EPSPS and Cry1Ab/Ac was proposed and combined with a lateral flow immunochromatographic assay,named“Dual-RPA-LFD”,to visualize the dual detection of genetically modified(GM)crops.In which,the herbicide tolerance gene CP4-EPSPS and the insect resistance gene Cry1Ab/Ac were selected as targets taking into account the current status of the most widespread application of insect resistance and herbicide tolerance traits and their stacked traits.Gradient diluted plasmids,transgenic standards,and actual samples were used as templates to conduct sensitivity,specificity,and practicality assays,respectively.The constructed method achieved the visual detection of plasmid at levels as low as 100 copies,demonstrating its high sensitivity.In addition,good applicability to transgenic samples was observed,with no cross-interference between two test lines and no influence from other genes.In conclusion,this strategy achieved the expected purpose of simultaneous detection of the two popular targets in GM crops within 20 min at 37°C in a rapid,equipmentfree field manner,providing a new alternative for rapid screening for transgenic assays in the field.展开更多
The practice of intercropping leguminous and gramineous crops is used for promoting sustainable agriculture,optimizing resource utilization,enhancing biodiversity,and reducing reliance on petroleum products.However,pr...The practice of intercropping leguminous and gramineous crops is used for promoting sustainable agriculture,optimizing resource utilization,enhancing biodiversity,and reducing reliance on petroleum products.However,promoting conventional intercropping strategies in modern agriculture can prove challenging.The innovative technology of soybean maize strip intercropping(SMSI)has been proposed as a solution.This system has produced remarkable results in improving domestic soybean and maize production for both food security and sustainable agriculture.In this article,we provide an overview of SMSI and explain how it differs from traditional intercropping.We also discuss the core principles that foster higher yields and the prospects for its future development.展开更多
Refinery sour water primarily originates from the tops of towers in various units and coker condensate,and cannot be discharged directly to a wastewater treatment plant due to high levels of chemical oxygen demand(COD...Refinery sour water primarily originates from the tops of towers in various units and coker condensate,and cannot be discharged directly to a wastewater treatment plant due to high levels of chemical oxygen demand(COD)and organic sulfur contents.Even after the recovery of H_(2)S from the sour water by the stripping process,the effluent still contains a high concentration of dissolved organic sulfur(DOS),which can have a huge bad influence.While chemical composition of dissolved organic matter(DOM)in refinery wastewater has been extensively studied,the investigation of recalcitrant DOS from sour waters remains unclear.In the present study,chemical composition of sour water DOMs(especially DOS)was investigated using fluorescence spectroscopy(excitation-emission matrix,EEM)and mass spectrometry,including gas chromatography-mass spectrometry(GC-MS)and high-resolution Orbitrap MS.The GC-MS and EEM results showed that volatile and low-aromaticity compounds were effectively removed during the stripping process,while compounds with high hydrophilicity and humification degree were found to be more recalcitrant.The Orbitrap MS results showed that weak-polar oxygenated sulfur compounds were easier to be removed than oxygenated compounds.However,the effluent still contained significant amounts of sulfur-containing compounds with multiple sulfur atoms,particularly in the form of highly unsaturated and aromatic compounds.The Orbitrap MS/MS results of CHOS-containing compounds from the effluent indicate that the sulfur atoms may exist as sulfonates,disulfide bonds,thioethers.Understanding the composition and structure of sour water DOS is crucial for the development of effective treatment processes that can target polysulfide compounds and minimize their impact on the environment.展开更多
The interfacial wettability and heat transfer behavior are crucial in the strip casting of high phosphorus-containing steel.A hightemperature simulation of strip casting was conducted using the droplet solidification ...The interfacial wettability and heat transfer behavior are crucial in the strip casting of high phosphorus-containing steel.A hightemperature simulation of strip casting was conducted using the droplet solidification technique with the aims to reveal the effects of phosphorus content on interfacial wettability,deposited film,and interfacial heat transfer behavior.Results showed that when the phosphorus content increased from 0.014wt%to 0.406wt%,the mushy zone enlarged,the complete solidification temperature delayed from1518.3 to 1459.4℃,the final contact angle decreased from 118.4°to 102.8°,indicating improved interfacial contact,and the maximum heat flux increased from 6.9 to 9.2 MW/m2.Increasing the phosphorus content from 0.081wt%to 0.406wt%also accelerated the film deposition rate from 1.57 to 1.73μm per test,resulting in a thickened naturally deposited film with increased thermal resistance that advanced the transition point of heat transfer from the fifth experiment to the third experiment.展开更多
Counterfeiting of modern banknotes poses a significant challenge,prompting the use of various preventive measures.One such measure is the magnetic anti-counterfeiting strip.However,due to its inherent weak magnetic pr...Counterfeiting of modern banknotes poses a significant challenge,prompting the use of various preventive measures.One such measure is the magnetic anti-counterfeiting strip.However,due to its inherent weak magnetic properties,visualizing its magnetic distribution has been a longstanding challenge.In this work,we introduce an innovative method by using a fiber optic diamond probe,a highly sensitive quantum sensor designed specifically for detecting extremely weak magnetic fields.We employ this probe to achieve high-resolution imaging of the magnetic fields associated with the RMB 50denomination anti-counterfeiting strip.Additionally,we conduct computer simulations by using COMSOL Multiphysics software to deduce the potential geometric characteristics and material composition of the magnetic region within the anti-counterfeiting strip.The findings and method presented in this study hold broader significance,extending the RMB 50 denomination to various denominations of the Chinese currency and other items that employ magnetic anti-counterfeiting strips.These advances have the potential to significantly improve and promote security measures in order to prevent the banknotes from being counterfeited.展开更多
An internal defect meter is an instrument to detect the internal inclusion defects of cold-rolled strip steel.The detection accuracy of the equipment can be evaluated based on the similarity of the multiple detection ...An internal defect meter is an instrument to detect the internal inclusion defects of cold-rolled strip steel.The detection accuracy of the equipment can be evaluated based on the similarity of the multiple detection data obtained for the same steel coil.Based on the cosine similarity model and eigenvalue matrix model,a comprehensive evaluation method to calculate the weighted average of similarity is proposed.Results show that the new method is consistent with and can even replace artificial evaluation to realize the automatic evaluation of strip defect detection results.展开更多
Many spot defects were found on the surface of a cold-rolled Fe-36%Ni alloy strip produced in a factory,which seriously affected the surface quality of the product.Through metallographic microscopy and scanning electr...Many spot defects were found on the surface of a cold-rolled Fe-36%Ni alloy strip produced in a factory,which seriously affected the surface quality of the product.Through metallographic microscopy and scanning electron microscopy analyses,it was found that the spot defects were caused by the residual oxide layer on the surface of the cold-rolled Fe-36%Ni alloy strip after hydrogen annealing.By properly increasing the grinding amount of the blank before cold rolling to remove the oxide layer,the spot defects on the surface of the cold-rolled strip were effectively eliminated,and the surface quality of the product was ensured.展开更多
The annealing process is usually used to heat-treat cold-deformed 304 stainless steel to improve its microstructure and properties to a certain extent;however,it requires a high temperature and a long time.Because the...The annealing process is usually used to heat-treat cold-deformed 304 stainless steel to improve its microstructure and properties to a certain extent;however,it requires a high temperature and a long time.Because the thickness of the ultrathin strip reaches the micrometer level,it has only one or several layers of grains in the thickness direction,and the control of morphology and performance is complex.In this study,pulsed current loading was used to replace traditional annealing for treating ultrathin strips of cold-rolled 304 stainless steel.After loading a 25 W pulsed current treatment for 5 min on the cold-rolled sample,which had a thickness of 0.035 mm and width of 6 mm,complete recrystallization occurred,and the mechanical properties were significantly improved.At this point,the measured temperature was 540°C.When annealing was used to treat the sample with the same temperature and for the same duration,the microstructure was still dominated by deformed crystals,and the mechanical properties were poor.When annealing was used to obtain a microstructure and properties similar to those obtained via 25 W electrical treatment,the required annealing temperature and time were 810°C and 60 min,respectively.Pulsed current can increase the vacancy diffusion flux in the sample,accelerate the atomic movement,reduce the recrystallization activation energy,and make the cold-rolled 304 stainless steel ultrathin strip completely recrystallize at a lower temperature and in a shorter time.As the current power continued to increase,the recrystallized grains grew.When the pulsed current power was increased to 25 W,the recrystallized grains grew negligibly.Both recrystallization and grain growth have power thresholds.This study provides a novel approach for regulating the microstructure and mechanical properties of ultrathin cold-rolled 304 stainless steel strips.展开更多
The strategic geographical location of Palestine, along with its topography, diversity of ecosystems and climatic changes, create a suitable environment for the presence of reptiles. Zoos in the Gaza Strip have a vari...The strategic geographical location of Palestine, along with its topography, diversity of ecosystems and climatic changes, create a suitable environment for the presence of reptiles. Zoos in the Gaza Strip have a variety of zoo animals including terrestrial, freshwater and marine reptiles. The present study aims to document the Palestinian reptiles held in captivity and/or kept stuffed at zoos in the Gaza Strip. Repeated visits to Gaza zoos were conducted over a ten-year period from 2010 to 2019 to achieve the purpose of the study. Digital cameras and guidebooks were used to document and identify Palestinian reptiles. In addition, interviews were carried out with zoo owners and workers and some reptile hunters who provide live and even dead specimens to Gaza zoos and had their specimens identified and photographed. A total of 29 Palestinian reptile species (one crocodile, four turtles, six lizards and 18 snake species), belonging to 3 orders and 15 families, were recorded as live or preserved specimens at Gaza zoos. The Nile Crocodile (Crocodylus niloticus), which went extinct in Palestine since the beginning of the 20th century, is the biggest reptilian encountered in the current study. Nearly all these reptiles were trapped using different means in the marine, freshwater and terrestrial environments of the Gaza Strip. Two of the highly threatened global sea turtle species were encountered: the Loggerhead Sea Turtle (Caretta caretta) and the Green Sea Turtle (Chelonia mydas). The Spur-thighed Tortoise (Testudo graeca), which is classified as vulnerable by the IUCN, is kept in relatively large numbers in cages at Gaza zoos. The Desert Monitor (Varanus griseus), Palestine Viper (Daboia palaestinae), and Syrian Black Snake (Coluber jugularis asianus) were the most occurring lizard and snake species at Gaza zoos. In conclusion, zoos are good tools that contribute to Palestinians’ knowledge of their wildlife resources. The ecological role of reptiles in their ecosystems requires Palestinians to protect and conserve them as well as all forms of wildlife in a sustainable manner.展开更多
In 1948, the colonial authorities began to build a strip of filao on Dakar’s northern coastline to stem the advance of sand dunes and protect the inter-dune basins (Niayes), the site of important market-garden produc...In 1948, the colonial authorities began to build a strip of filao on Dakar’s northern coastline to stem the advance of sand dunes and protect the inter-dune basins (Niayes), the site of important market-garden production. Today, the dynamics of the filao strip in the Dakar region tend to take on significant proportions under the impetus of natural and anthropogenic factors that threaten its sustainability. It is in this context that this study attempts to analyze the relationship between the dynamics of the land-use units of the filao strip and the natural and anthropogenic factors at the origin of its modification. The diachronic study of Landsat Multispectral Scanner System (1978), Thematic Mapper (1990), Enhance Thematic Mapper Plus (2006) and Operational Land Imager (2020) satellite images through the directed pixel-oriented classification method, cartographic information systems and qualitative surveys have been applied. The results based on the analysis of the data obtained show that both natural and anthropogenic factors are at the root of the profound changes observed in the filao strip. They reveal that the average annual progression rates of the open filao strip and the built-up area exceed 100%, and that the closed filao strip classes regressed by −16.2%, the sand dunes by −62.9% and the beach by −18.2% between 1978 and 2020. In short, the study shows that the landscape of the Niayes zone is marked by anthropization, leading to the degradation of the filao strip and natural ecosystems. The shrinking surface area of the increasingly anthropized closed filao strip represents a threat to its future.展开更多
A field plot experiment was conducted to explore the control effects and safety of different post-emergence herbicides on weeds in the field with soybeanmaize strip intercropping.The control effects of five post-emerg...A field plot experiment was conducted to explore the control effects and safety of different post-emergence herbicides on weeds in the field with soybeanmaize strip intercropping.The control effects of five post-emergence herbicides on weeds in soybean rows and five post-emergence herbicides for weeds in maize rows were determined.The results showed that after 14 d of application,the control effects of quizalofop-P-ethyl·fomesafen 35%EW and fluoroglycofen 10% EC on weeds in soybean rows were 85.61% and 84.34%,respectively.The control effects of starane 288 g/L EC and mesotrione·atrazine 30% OD were 90.04% and 87.34%,respectively.The phytotoxicity index decreased gradually over time,which indicated that the herbicides were safe for soybean and maize.Moreover,the herbicides increased the yield of soybean and maize by 11.18%-19.42%and 13.11%-25.77%,respectively.These four herbicides can effectively control annual and perennial weeds in the field with soybean-maize strip intercropping at the recommended dosage and can be widely applied in production.展开更多
A new copper strip production technology combined with continuous extrusion and rolling technology was proposed. The roll velocity must first be matched with the continuous extrusion velocity to achieve continuous ext...A new copper strip production technology combined with continuous extrusion and rolling technology was proposed. The roll velocity must first be matched with the continuous extrusion velocity to achieve continuous extrusion and roll forming. The bite condition of continuous extrusion was determined, and the compatibility equation between the roll velocity and parameters such as the extrusion wheel velocity, reduction, and strip size was established through mechanical by plastic theoretical calculations. The finite element model of continuous extrusion and rolling was then established by using the TLJ400 continuous extrusion machine with a roll diameter of 200 mm. The relationship between the continuous extrusion and rolling velocities was determined through numerical simulations by software DEFORM-3D, and the accuracy of compatibility equation of velocity was verified.展开更多
[Objective] New SSR primers were designed and screened to apply in the backcross breeding for modified resistance against rice stripe virus.[Method] The conventional late japonica rice varieties including 502 with hig...[Objective] New SSR primers were designed and screened to apply in the backcross breeding for modified resistance against rice stripe virus.[Method] The conventional late japonica rice varieties including 502 with high resistance to stripe virus,Xiushui 09 with high susceptibility to stripe virus and their derived strains were adopted as the test materials,SSR and SAPR markers were used to locate RSV1 gene with high resistance against stripe virus,and three pairs of SSR markers （M-11-1,M-11-2,M-11-3） were further designed.Through screening and analysis,M-11-3 was selected as the RSV1 detection marker gene for tracking RSV1 gene,thus RSV1 gene was successfully introduced to the backcross breeding of late japonica rice varieties such as Xiushui 09,and the resistance expression of different strains was identified.[Result]The resistance of improved strains against stripe virus was significantly higher than Xiushui 09,the resistance of most strains was close to the level of donor,and the expression of resistance among years was stable.Therefore,the resistance effect of RSV1 gene used in the test was very obvious,which was accurate with the assisted selection of RSV1 gene linked markers M-11-3.[Conclusion]The study certified the feasibility of molecular markers application in resistance improvement against rice stripe virus,which also showed that optimization and development of new marker genes could effectively improve the efficiency of marker-assisted selection.展开更多
基金supported by the Centre for Development of Advanced Computing (CDAC), Pune
文摘In hilly regions,the existence of surface cracks in rock mass induces a potential threat to structural stability.Thus,the present research aims to explore the impact of surface cracks on the loadbearing capacity of strip footing placed on the rock mass.By taking into account the various boundary constraints across the surface of crack edges,the study investigates the presence of two categories of surface cracks,namely(1)separated crack,and(2)fine crack.The lower bound limit analysis is employed in conjunction with the finite element method(LBFELA)to conduct the numerical analysis.In order to evaluate rock mass yielding,the power conic programming(PCP)method is utilized to implement the generalized Hoek-Brown(GHB)failure criterion.The stability of the strip footing is analyzed by determining the bearing capacity factor(Nσγ),which is presented in the form of design charts by varying the strength parameters of rock,including the Geological Strength Index(GSI),Hoek-Brown material parameter(mi),Disturbance factor(D),and Normalised Uniaxial Compressive Strength(σci/γB),whereγis the unit weight of rock mass,and B is the width of strip footing.The study also investigates the impact of cracks on strip footings,considering different positions of the crack(LC)and depths of the crack(DC).The results demonstrate that the influence of the fine crack is only noticeable until the LC/B ratio reaches 6.However,for the separated crack,its impact remains significant even when the LC/B ratio exceeds 16.The appearance of fine crack at the edge of the footing results in a decrease in the magnitude Nσγof up to 45%,indicating a substantial reduction in the stability of the footing.The failure patterns are presented and discussed in detail for various cases in this study to examine the effect of surface cracks on the strip footing and to address the extent of the plastic collapse.
基金supported by the National MCF Energy R&D Program of China(MOST 2018YFE0310200)in part by the National Natural Science Foundation of China(Nos.11705242,11805138,12175156)in part by the Fundamental Research Funds for the Central Universities(Nos.YJ201820,YJ201954)in China.
文摘Stripping units take a key role in the neutral particle analyzer(NPA).A renovated gas-stripping unit was constructed for the newly designed E//B NPA.Using H_(2)as the working gas,we measured the gas inlet pressure(P_(0))and vacuum chamber pressure(P_(3)).The pressure distribution inside the gas-stripping room was calculated with Ansys Fluent,using the measured P_(0)and P_(3)as boundary conditions.The stripping efficiency of the stripping unit was then simulated utilizing the Geant4 Monte Carlo code for the H and D particles.The pressure P_(0)=40 Pa,which is one-sixth of what found in the previous design and corresponds to a thickness of 1.27×10^(17)atoms∕cm^(2),was obtained as the optimum working pressure for the upgraded stripping unit.An 50 kV electron cyclotron resonance(ECR)ion source platform was designed and constructed for E//B NPA calibration,and its performance has been measured.Using the ECR ion source platform,we measured the efficiency of the stripping unit through an inverse experiment with proton beams.We compared the current ratios of measurements with and without H_(2)gas to Geant4 simulation results.We found adequate agreement between the overall trends of the experiment and the simulation.The significant deviation for incident energies below 20 keV may result from the scattering effects of low-energy protons,leading to reduced accuracy in single-scattering physics in Geant4 simulations.Applying the scattering corrections observed in the reverse experiments obtains more accurate stripping efficiencies for H and D atoms in the energy range of 20–200 keV and the global efficiency with the maximum values of 95.0%for H atoms and 78.9%for D atoms at 200 keV.
基金supported by the National Natural Science Foundation of China(No.52130408)the Natural Science Foundation of Hunan Province,China(No.2022JJ10081).
文摘The complex producing procedures and high energy-consuming limit the large-scale production and application of advanced high-strength steels(AHSSs).In this study,the direct strip casting(DSC)technology with unique sub-rapid solidification characteristics and cost advantages was applied to the production of low-alloy Si-Mn steel with the help of quenching&partitioning(Q&P)concept to address these issues.Compared this method with the conventional compact strip production(CSP)process,the initial microstructure formed under different solidification conditions and the influence of heat treatment processes on the final mechanical properties were in-vestigated.The results show that the initial structure of the DSC sample is a dual-phase structure composed of fine lath martensite and bainite,while the initial structure of the CSP sample consists of pearlite and ferrite.The volume fraction and carbon content of retained austenite(RA)in DSC samples are usually higher than those in CSP samples after the same Q&P treatment.DSC samples typically demonstrate better comprehensive mechanical properties than the CSP sample.The DSC sample partitioned at 300℃ for 300 s(DSC-Pt300)achieves the best comprehensive mechanical properties,with yield strength(YS)of 1282 MPa,ultimate tensile strength(UTS)of 1501 MPa,total elongation(TE)of 21.5%,and product of strength and elongation(PSE)as high as 32.3 GPa·%.These results indicate that the excellent mechanical properties in low-alloy Si-Mn steel can be obtained through a simple process(DSC-Q&P),which also demonstrates the superiority of DSC technology in manufacturing AHSSs.
基金supported by the Scientific and Innovative Action Plan of Shanghai(21N31900800)Shanghai Rising-Star Program(23QB1403500)+4 种基金the Shanghai Sailing Program(20YF1443000)Shanghai Science and Technology Commission,the Belt and Road Project(20310750500)Talent Project of SAAS(2023-2025)Runup Plan of SAAS(ZP22211)the SAAS Program for Excellent Research Team(2022(B-16))。
文摘Traditional transgenic detection methods require high test conditions and struggle to be both sensitive and efficient.In this study,a one-tube dual recombinase polymerase amplification(RPA)reaction system for CP4-EPSPS and Cry1Ab/Ac was proposed and combined with a lateral flow immunochromatographic assay,named“Dual-RPA-LFD”,to visualize the dual detection of genetically modified(GM)crops.In which,the herbicide tolerance gene CP4-EPSPS and the insect resistance gene Cry1Ab/Ac were selected as targets taking into account the current status of the most widespread application of insect resistance and herbicide tolerance traits and their stacked traits.Gradient diluted plasmids,transgenic standards,and actual samples were used as templates to conduct sensitivity,specificity,and practicality assays,respectively.The constructed method achieved the visual detection of plasmid at levels as low as 100 copies,demonstrating its high sensitivity.In addition,good applicability to transgenic samples was observed,with no cross-interference between two test lines and no influence from other genes.In conclusion,this strategy achieved the expected purpose of simultaneous detection of the two popular targets in GM crops within 20 min at 37°C in a rapid,equipmentfree field manner,providing a new alternative for rapid screening for transgenic assays in the field.
基金supported by the National Natural Science Foundation of China(31971853)。
文摘The practice of intercropping leguminous and gramineous crops is used for promoting sustainable agriculture,optimizing resource utilization,enhancing biodiversity,and reducing reliance on petroleum products.However,promoting conventional intercropping strategies in modern agriculture can prove challenging.The innovative technology of soybean maize strip intercropping(SMSI)has been proposed as a solution.This system has produced remarkable results in improving domestic soybean and maize production for both food security and sustainable agriculture.In this article,we provide an overview of SMSI and explain how it differs from traditional intercropping.We also discuss the core principles that foster higher yields and the prospects for its future development.
基金supported by the National Natural Science Foundation of China(42003059)State Key Laboratory of Coal Mining and Clean Utilization(2021-CMCU-KF009)the Science Foundation of China University of Petroleum,Beijing(No.2462023YJRC003)。
文摘Refinery sour water primarily originates from the tops of towers in various units and coker condensate,and cannot be discharged directly to a wastewater treatment plant due to high levels of chemical oxygen demand(COD)and organic sulfur contents.Even after the recovery of H_(2)S from the sour water by the stripping process,the effluent still contains a high concentration of dissolved organic sulfur(DOS),which can have a huge bad influence.While chemical composition of dissolved organic matter(DOM)in refinery wastewater has been extensively studied,the investigation of recalcitrant DOS from sour waters remains unclear.In the present study,chemical composition of sour water DOMs(especially DOS)was investigated using fluorescence spectroscopy(excitation-emission matrix,EEM)and mass spectrometry,including gas chromatography-mass spectrometry(GC-MS)and high-resolution Orbitrap MS.The GC-MS and EEM results showed that volatile and low-aromaticity compounds were effectively removed during the stripping process,while compounds with high hydrophilicity and humification degree were found to be more recalcitrant.The Orbitrap MS results showed that weak-polar oxygenated sulfur compounds were easier to be removed than oxygenated compounds.However,the effluent still contained significant amounts of sulfur-containing compounds with multiple sulfur atoms,particularly in the form of highly unsaturated and aromatic compounds.The Orbitrap MS/MS results of CHOS-containing compounds from the effluent indicate that the sulfur atoms may exist as sulfonates,disulfide bonds,thioethers.Understanding the composition and structure of sour water DOS is crucial for the development of effective treatment processes that can target polysulfide compounds and minimize their impact on the environment.
基金supported from the National Natural Science Foundation of China(Nos.52204356,52274342,and 52130408)the Natural Science Foundation of Hunan Province,China(Nos.2023JJ40762 and 2021JJ40731)。
文摘The interfacial wettability and heat transfer behavior are crucial in the strip casting of high phosphorus-containing steel.A hightemperature simulation of strip casting was conducted using the droplet solidification technique with the aims to reveal the effects of phosphorus content on interfacial wettability,deposited film,and interfacial heat transfer behavior.Results showed that when the phosphorus content increased from 0.014wt%to 0.406wt%,the mushy zone enlarged,the complete solidification temperature delayed from1518.3 to 1459.4℃,the final contact angle decreased from 118.4°to 102.8°,indicating improved interfacial contact,and the maximum heat flux increased from 6.9 to 9.2 MW/m2.Increasing the phosphorus content from 0.081wt%to 0.406wt%also accelerated the film deposition rate from 1.57 to 1.73μm per test,resulting in a thickened naturally deposited film with increased thermal resistance that advanced the transition point of heat transfer from the fifth experiment to the third experiment.
基金Project supported by the National Key Research and Development Program of China (Grant No.2021YFB2012600)the Shanghai Aerospace Science and Technology Innovation Fund,China (Grant No.SAST-2022-102)。
文摘Counterfeiting of modern banknotes poses a significant challenge,prompting the use of various preventive measures.One such measure is the magnetic anti-counterfeiting strip.However,due to its inherent weak magnetic properties,visualizing its magnetic distribution has been a longstanding challenge.In this work,we introduce an innovative method by using a fiber optic diamond probe,a highly sensitive quantum sensor designed specifically for detecting extremely weak magnetic fields.We employ this probe to achieve high-resolution imaging of the magnetic fields associated with the RMB 50denomination anti-counterfeiting strip.Additionally,we conduct computer simulations by using COMSOL Multiphysics software to deduce the potential geometric characteristics and material composition of the magnetic region within the anti-counterfeiting strip.The findings and method presented in this study hold broader significance,extending the RMB 50 denomination to various denominations of the Chinese currency and other items that employ magnetic anti-counterfeiting strips.These advances have the potential to significantly improve and promote security measures in order to prevent the banknotes from being counterfeited.
文摘An internal defect meter is an instrument to detect the internal inclusion defects of cold-rolled strip steel.The detection accuracy of the equipment can be evaluated based on the similarity of the multiple detection data obtained for the same steel coil.Based on the cosine similarity model and eigenvalue matrix model,a comprehensive evaluation method to calculate the weighted average of similarity is proposed.Results show that the new method is consistent with and can even replace artificial evaluation to realize the automatic evaluation of strip defect detection results.
文摘Many spot defects were found on the surface of a cold-rolled Fe-36%Ni alloy strip produced in a factory,which seriously affected the surface quality of the product.Through metallographic microscopy and scanning electron microscopy analyses,it was found that the spot defects were caused by the residual oxide layer on the surface of the cold-rolled Fe-36%Ni alloy strip after hydrogen annealing.By properly increasing the grinding amount of the blank before cold rolling to remove the oxide layer,the spot defects on the surface of the cold-rolled strip were effectively eliminated,and the surface quality of the product was ensured.
基金Supported by National Natural Science Foundation of China(Grant Nos.51974196,51804215)China Postdoctoral Science Foundation(Grant No.2020T130463)+1 种基金Shanxi Provincial Key Research and Development Program(Grant No.201903D421047)Shanxi Provincial Science and Technology Major Projects(Grant No.20181102015)。
文摘The annealing process is usually used to heat-treat cold-deformed 304 stainless steel to improve its microstructure and properties to a certain extent;however,it requires a high temperature and a long time.Because the thickness of the ultrathin strip reaches the micrometer level,it has only one or several layers of grains in the thickness direction,and the control of morphology and performance is complex.In this study,pulsed current loading was used to replace traditional annealing for treating ultrathin strips of cold-rolled 304 stainless steel.After loading a 25 W pulsed current treatment for 5 min on the cold-rolled sample,which had a thickness of 0.035 mm and width of 6 mm,complete recrystallization occurred,and the mechanical properties were significantly improved.At this point,the measured temperature was 540°C.When annealing was used to treat the sample with the same temperature and for the same duration,the microstructure was still dominated by deformed crystals,and the mechanical properties were poor.When annealing was used to obtain a microstructure and properties similar to those obtained via 25 W electrical treatment,the required annealing temperature and time were 810°C and 60 min,respectively.Pulsed current can increase the vacancy diffusion flux in the sample,accelerate the atomic movement,reduce the recrystallization activation energy,and make the cold-rolled 304 stainless steel ultrathin strip completely recrystallize at a lower temperature and in a shorter time.As the current power continued to increase,the recrystallized grains grew.When the pulsed current power was increased to 25 W,the recrystallized grains grew negligibly.Both recrystallization and grain growth have power thresholds.This study provides a novel approach for regulating the microstructure and mechanical properties of ultrathin cold-rolled 304 stainless steel strips.
文摘The strategic geographical location of Palestine, along with its topography, diversity of ecosystems and climatic changes, create a suitable environment for the presence of reptiles. Zoos in the Gaza Strip have a variety of zoo animals including terrestrial, freshwater and marine reptiles. The present study aims to document the Palestinian reptiles held in captivity and/or kept stuffed at zoos in the Gaza Strip. Repeated visits to Gaza zoos were conducted over a ten-year period from 2010 to 2019 to achieve the purpose of the study. Digital cameras and guidebooks were used to document and identify Palestinian reptiles. In addition, interviews were carried out with zoo owners and workers and some reptile hunters who provide live and even dead specimens to Gaza zoos and had their specimens identified and photographed. A total of 29 Palestinian reptile species (one crocodile, four turtles, six lizards and 18 snake species), belonging to 3 orders and 15 families, were recorded as live or preserved specimens at Gaza zoos. The Nile Crocodile (Crocodylus niloticus), which went extinct in Palestine since the beginning of the 20th century, is the biggest reptilian encountered in the current study. Nearly all these reptiles were trapped using different means in the marine, freshwater and terrestrial environments of the Gaza Strip. Two of the highly threatened global sea turtle species were encountered: the Loggerhead Sea Turtle (Caretta caretta) and the Green Sea Turtle (Chelonia mydas). The Spur-thighed Tortoise (Testudo graeca), which is classified as vulnerable by the IUCN, is kept in relatively large numbers in cages at Gaza zoos. The Desert Monitor (Varanus griseus), Palestine Viper (Daboia palaestinae), and Syrian Black Snake (Coluber jugularis asianus) were the most occurring lizard and snake species at Gaza zoos. In conclusion, zoos are good tools that contribute to Palestinians’ knowledge of their wildlife resources. The ecological role of reptiles in their ecosystems requires Palestinians to protect and conserve them as well as all forms of wildlife in a sustainable manner.
文摘In 1948, the colonial authorities began to build a strip of filao on Dakar’s northern coastline to stem the advance of sand dunes and protect the inter-dune basins (Niayes), the site of important market-garden production. Today, the dynamics of the filao strip in the Dakar region tend to take on significant proportions under the impetus of natural and anthropogenic factors that threaten its sustainability. It is in this context that this study attempts to analyze the relationship between the dynamics of the land-use units of the filao strip and the natural and anthropogenic factors at the origin of its modification. The diachronic study of Landsat Multispectral Scanner System (1978), Thematic Mapper (1990), Enhance Thematic Mapper Plus (2006) and Operational Land Imager (2020) satellite images through the directed pixel-oriented classification method, cartographic information systems and qualitative surveys have been applied. The results based on the analysis of the data obtained show that both natural and anthropogenic factors are at the root of the profound changes observed in the filao strip. They reveal that the average annual progression rates of the open filao strip and the built-up area exceed 100%, and that the closed filao strip classes regressed by −16.2%, the sand dunes by −62.9% and the beach by −18.2% between 1978 and 2020. In short, the study shows that the landscape of the Niayes zone is marked by anthropization, leading to the degradation of the filao strip and natural ecosystems. The shrinking surface area of the increasingly anthropized closed filao strip represents a threat to its future.
文摘A field plot experiment was conducted to explore the control effects and safety of different post-emergence herbicides on weeds in the field with soybeanmaize strip intercropping.The control effects of five post-emergence herbicides on weeds in soybean rows and five post-emergence herbicides for weeds in maize rows were determined.The results showed that after 14 d of application,the control effects of quizalofop-P-ethyl·fomesafen 35%EW and fluoroglycofen 10% EC on weeds in soybean rows were 85.61% and 84.34%,respectively.The control effects of starane 288 g/L EC and mesotrione·atrazine 30% OD were 90.04% and 87.34%,respectively.The phytotoxicity index decreased gradually over time,which indicated that the herbicides were safe for soybean and maize.Moreover,the herbicides increased the yield of soybean and maize by 11.18%-19.42%and 13.11%-25.77%,respectively.These four herbicides can effectively control annual and perennial weeds in the field with soybean-maize strip intercropping at the recommended dosage and can be widely applied in production.
基金Supported by the National Natural Science Foundation of China under Grant No.60173039(国家自然科学基金)the Special Foundation of 985 Project of SUN YAT-SEN University of China (中山大学985工程专项资金)
基金Project(51175055) supported by the National Natural Science Foundation of ChinaProject(201102020) supported by the Natural Science Foundation of Liaoning Province,ChinaProject(2011BAE23B01) supported by the National Key Technology R&D Program of China
文摘A new copper strip production technology combined with continuous extrusion and rolling technology was proposed. The roll velocity must first be matched with the continuous extrusion velocity to achieve continuous extrusion and roll forming. The bite condition of continuous extrusion was determined, and the compatibility equation between the roll velocity and parameters such as the extrusion wheel velocity, reduction, and strip size was established through mechanical by plastic theoretical calculations. The finite element model of continuous extrusion and rolling was then established by using the TLJ400 continuous extrusion machine with a roll diameter of 200 mm. The relationship between the continuous extrusion and rolling velocities was determined through numerical simulations by software DEFORM-3D, and the accuracy of compatibility equation of velocity was verified.
基金Supported by Major Projects in Zhejiang Province(2006E10053)National Science and Technology Support Program (2006BAD01A01-5)~~
文摘[Objective] New SSR primers were designed and screened to apply in the backcross breeding for modified resistance against rice stripe virus.[Method] The conventional late japonica rice varieties including 502 with high resistance to stripe virus,Xiushui 09 with high susceptibility to stripe virus and their derived strains were adopted as the test materials,SSR and SAPR markers were used to locate RSV1 gene with high resistance against stripe virus,and three pairs of SSR markers （M-11-1,M-11-2,M-11-3） were further designed.Through screening and analysis,M-11-3 was selected as the RSV1 detection marker gene for tracking RSV1 gene,thus RSV1 gene was successfully introduced to the backcross breeding of late japonica rice varieties such as Xiushui 09,and the resistance expression of different strains was identified.[Result]The resistance of improved strains against stripe virus was significantly higher than Xiushui 09,the resistance of most strains was close to the level of donor,and the expression of resistance among years was stable.Therefore,the resistance effect of RSV1 gene used in the test was very obvious,which was accurate with the assisted selection of RSV1 gene linked markers M-11-3.[Conclusion]The study certified the feasibility of molecular markers application in resistance improvement against rice stripe virus,which also showed that optimization and development of new marker genes could effectively improve the efficiency of marker-assisted selection.
