Despite the growing demand for transparent conductive films in smart and wearable electronics for electromagnetic interference(EMI)shielding,achieving a flexible EMI shielding film,while maintaining a high transmittan...Despite the growing demand for transparent conductive films in smart and wearable electronics for electromagnetic interference(EMI)shielding,achieving a flexible EMI shielding film,while maintaining a high transmittance remains a significant challenge.Herein,a flexible,transparent,and conductive copper(Cu)metal mesh film for EMI shielding is fabricated by self-forming crackle template method and electroplating technique.The Cu mesh film shows an ultra-low sheet resistance(0.18Ω□^(-1)),high transmittance(85.8%@550 nm),and ultra-high figure of merit(>13,000).It also has satisfactory stretchability and mechanical stability,with a resistance increases of only 1.3%after 1,000 bending cycles.As a stretchable heater(ε>30%),the saturation temperature of the film can reach over 110°C within 60 s at 1.00 V applied voltage.Moreover,the metal mesh film exhibits outstanding average EMI shielding effectiveness of 40.4 dB in the X-band at the thickness of 2.5μm.As a demonstration,it is used as a transparent window for shielding the wireless communication electromagnetic waves.Therefore,the flexible and transparent conductive Cu mesh film proposed in this work provides a promising candidate for the next-generation EMI shielding applications.展开更多
With the increasing demand for terahertz(THz)technology in security inspection,medical imaging,and flexible electronics,there is a significant need for stretchable and transparent THz electromagnetic interference(EMI)...With the increasing demand for terahertz(THz)technology in security inspection,medical imaging,and flexible electronics,there is a significant need for stretchable and transparent THz electromagnetic interference(EMI)shielding materials.Existing EMI shielding materials,like opaque metals and carbon-based films,face challenges in achieving both high transparency and high shielding efficiency(SE).Here,a wrinkled structure strategy was proposed to construct ultra-thin,stretchable,and transparent terahertz shielding MXene films,which possesses both isotropous wrinkles(height about 50 nm)and periodic wrinkles(height about 500 nm).Compared to flat film,the wrinkled MXene film(8 nm)demonstrates a remarkable 36.5%increase in SE within the THz band.The wrinkled MXene film exhibits an EMI SE of 21.1 dB at the thickness of 100 nm,and an average EMI SE/t of 700 dBμm^(−1)over the 0.1-10 THz.Theoretical calculations suggest that the wrinkled structure enhances the film’s conductivity and surface plasmon resonances,resulting in an improved THz wave absorption.Additionally,the wrinkled structure enhances the MXene films’stretchability and stability.After bending and stretching(at 30%strain)cycles,the average THz transmittance of the wrinkled film is only 0.5%and 2.4%,respectively.The outstanding performances of the wrinkled MXene film make it a promising THz electromagnetic shielding materials for future smart windows and wearable electronics.展开更多
Previous studies have suggested that the incidence of post-traumatic stress disorder in earthquake rescue workers is relatively high. Risk factors for this disorder include demographic characteristics, earthquake-rela...Previous studies have suggested that the incidence of post-traumatic stress disorder in earthquake rescue workers is relatively high. Risk factors for this disorder include demographic characteristics, earthquake-related high-risk factors, risk factors in the rescue process, personality, social support and coping style. This study examined the current status of a unit of 1 040 rescue workers who participated in earthquake relief for the Wenchuan earthquake that occurred on May 12th, 2008. Post-traumatic stress disorder was diagnosed primarily using the Clinician-Administered Post-traumatic Stress Disorder Scale during structured interviews. Univariate and multivariate sta-tistical analyses were used to examine major risk factors that contributed to the incidence of post-traumatic stress disorder. Results revealed that the incidence of this disorder in the rescue group was 5.96%. The impact factors in univariate analysis included death of family members, contact with corpses or witnessing of the deceased or seriously injured, near-death experience, severe injury or mental trauma in the rescue process and working at the epicenter of the earthquake. Correlation analysis suggested that post-traumatic stress disorder was positively correlated with psychotic and neurotic personalities, negative coping and low social support. Impact factors in mul-tivariate logistic regression analysis included near-death experience, severe injury or mental trauma, working in the epicenter of the rescue, neurotic personality, negative coping and low social support, among which low social support had the largest odds ratio of 20.42. Findings showed that the oc-currence of post-traumatic stress disorder was the result of the interaction of multiple factors.展开更多
Organic solar cells(OSCs)have attracted much interest in the past few decades because of their advantages,such as being lightweight,low cost,simple preparation process,and environmental friendliness.While researchers ...Organic solar cells(OSCs)have attracted much interest in the past few decades because of their advantages,such as being lightweight,low cost,simple preparation process,and environmental friendliness.While researchers have made significant progress on the active layer materials of OSCs,the interface engineering is another entry point for upgrading the photovoltaic performance of OSCs.Significantly,the interface modification materials,including anode interfacial materials and cathode interfacial materials,are two essential parts of interfacial layers for OSCs,in which the excellent interfacial materials can realize the very high-performance photovoltaic cells.Among these interfacial materials,the anode interfacial layers(AILs)play a crucial role in improving photovoltaic performance.This review expresses a detailed conclusion of the development of anode interfacial materials and an outlook on future trends for OSCs.展开更多
What is already known about this topic?The level of molybdenum(Mo)in a mother’s urine has been linked to the growth rate of the fetus and the blood pressure levels in children.What is added by this report?We evaluate...What is already known about this topic?The level of molybdenum(Mo)in a mother’s urine has been linked to the growth rate of the fetus and the blood pressure levels in children.What is added by this report?We evaluated the variations in maternal plasma Mo concentrations throughout pregnancy and their potential association with the risk of spontaneous preterm birth(SPB).What are the implications for public health practice?Future research must determine the Mo levels in pregnant women across various regions in China.Moreover,particular attention needs to be given to the potential increase in Mo concentration throughout pregnancy and its possible adverse impacts on the health of both the mother and the fetus.展开更多
Based on 14C dating and core sediments survey, phytolith records are employed to reconstruct paleovegetation and paleoclimate in the Jianghan Plain in the middle reach of the Yangtze River. Phytoliths identified are a...Based on 14C dating and core sediments survey, phytolith records are employed to reconstruct paleovegetation and paleoclimate in the Jianghan Plain in the middle reach of the Yangtze River. Phytoliths identified are assigned into 21 well-described morphotypes and divided into four groups （Poaceae, fern, coniferous and broad-leaved）. The phytolith assemblages together with warmth index （Iw） are divided into 18 ecological zones, which reflect a complete vegetation history related to climate change in the middle reach of the Yangtze River during the past 15000 years. On the basis of the correlation ofphytolith records with the paleoclimatic indicators from stalagmite, peatland, North Atlantic deep-sea sediments, Loess Plateau of Central China, and Arabic Sea sediments, eight climatic phases are identified included Last Glacial Maximum （LGM） （20- 14.8 cal kaBP）, Last Deglaciation （LDG） （14.8-11.9 cal kaBP）, low-temperature phase in the Early Holocene （11.9-8 cal kaBP）, Holocene Opti- mum （8-4.9cal kaBP）, Holocene Katathermal （4.9- 1.1 cal kaBP）, Medieval Warmth Period （MWP） （1.1- 0.7 cal kaBP）, Little Ice Age （LIA） （0.7-0.15 cal kaBP）, and Modem Warming （0.15 cal kaBP-present）. Climatic events such as Bolling-Allerod warm intervals, Older Dryas, Inter-Allerod Cold Period, and Younger Dryas, and eight Holocene Bond events （B1-8） have been identified since the LDG. Our results demonstrate that the evolution of the climate in the research area has a strong link with the Indian Summer Monsoon （SW Monsoon）, Asian Summer Monsoon （SE Monsoon）, and Holocene events in North Atlantic simultaneously, which might indicate that solar variability affects the Earth surface climate system at the centennial and millennial scales.展开更多
Lipids in stalagmites have been shown the potential for the paleoclimate reconstruction. However, the low lipid content leads to the difficulty in gaining high resolution lipid record in stalagmites because large mass...Lipids in stalagmites have been shown the potential for the paleoclimate reconstruction. However, the low lipid content leads to the difficulty in gaining high resolution lipid record in stalagmites because large mass of samples are required. Previous studies have validated that the acid digestion can improve the yield of lipids, especially fatty acids （FAs） and 3-hydroxy fatty acids （3- OH-FAs）. In order to obtain more content of FAs and 3- OH-FAs with limited stalagmite sample weight, we investigate here how the acid digestion conditions （HC1 concentration, heating temperature and time duration） could affect the yields of FAs and 3-OH-FAs. Under different concentration of HC1, from 2.0 to 6.0 mol/L, the FAs keep the same step in content variation with 3-OH- FAs, and the highest yields of both two appeared under the 3 mol/L HCl. The content of 3-OH-FAs increases posi- tively with the heating temperature from 80℃ to 150℃, while FAs showed the highest content at 130℃. Both of FAs and 3-OH-FAs firstly increased to a high content and then decreased as the heating time duration varies from 1.0 to 4.0 h, with the highest yields of both two being at 3.0 h. Consequently, we suggest the optimized acid digestion condition is under 3 mol/L HC1, heating at 130℃ for 3 h and 5 g of each stalagmite sample are sufficient for the lipid analysis.展开更多
Owing to the conductance-adjustable performance,the emerging two-terminal memristors are promising candidates for artificial synapses and brain-spired neuromorphic computing.Although memristors based on molybdenum dis...Owing to the conductance-adjustable performance,the emerging two-terminal memristors are promising candidates for artificial synapses and brain-spired neuromorphic computing.Although memristors based on molybdenum disulfide(MoS_(2))have displayed outstanding performance,such as thermal stability and high energy efficiency,reports on memristors based on MoS_(2) as the functional layer to simulate synaptic behavior are limited.Herein,a homologous Mo_(2)C/MoS_(2)-based memristor is prepared by partially sulfuring two-dimensional Mo_(2)C crystal.The memristor shows good stability,excellent retention(~104 s)and endurance(>100 cycles),and a high ON/OFF ratio(>10^(3)).Moreover,for comprehensively mimicking biological synapses,the essential synaptic functions of the device are systematically analyzed,including paired-pulse facilitation(PPF),short-term plasticity(STP),long-term plasticity(LTP),long-term depression(LTD),and the transitions from STP to LTP.Notably,this artificial synapse could keep a highlevel stable memory for a long time(60 s)after repeated stimulation.These results prove that our device is highly desirable for biological synapses,which show great potential for application in future high-density storage and neuromorphic computing systems.展开更多
The Ediacaran Period(~635–539 Ma)was a critical time in Earth history due to large increases in atmospheric and oceanic oxygen levels and rapid evolution of early animals[1].It was also an interval of major climatic ...The Ediacaran Period(~635–539 Ma)was a critical time in Earth history due to large increases in atmospheric and oceanic oxygen levels and rapid evolution of early animals[1].It was also an interval of major climatic and geochemical perturbations,such as the~580-Ma Gaskiers Glaciation[2](Fig.S1 online)and the late Ediacaran Shuram Excursion(SE;also known as DOUNCE or EN3 in South China,see Fig.S2 online),which was the largest negative carbonate carbon isotope(δ13Ccarb)excursion in Earth history[3,4].In contrast to established redox,biological,and C-cycling records for the Ediacaran,however,no secular,high-resolution paleotemperature record with climatic significance has been reported to date,impeding our understanding of the relationships among major environmental,biological,geochemical,and climatic processes and milestones.展开更多
The use of bio-based biomass construction materials has the advantage of helping to reduce fossil energy demand,protecting the environment from carbon dioxide emission and reducing the production of non-degradable was...The use of bio-based biomass construction materials has the advantage of helping to reduce fossil energy demand,protecting the environment from carbon dioxide emission and reducing the production of non-degradable waste.This paper used resin-modified soy protein(SP)adhesive to combine rice straw stalks,and made straw-soy protein composites(SSPC)material.The physical properties,compressive behavior and stability during wetting drying cycles of SSPC were measured.Due to water evaporation,the SP matrix is full of connected pores,resulting to its physical properties of small density,high shrinkage ratio and low thermal conductivity,which are 0.24 g/cm^(3),16.2%,and 0.065 W/(m•K),respectively.Adding straw is helpful to the physical properties of SP matrix,leading to an obvious decrease in shrinkage ratio and thermal conductivity of SSPC,which are 8.51%and 0.075 W/m•K.Furthermore,the compressive load-displacement curves of SSPC groups divide into two types:divergent and convergent.The compressive strength of divergent samples is decided by the critical displacement determined according to the convergent specimens.It shows that straw stalk proves the positive effect on the compressive property of SP matrix.As to the mass of SSPC samples during the wetting drying cycles,it drops apparently in the initial three cycles,and becomes negligible from the fifth cycle,meaning that the stability of SSPC during wetting drying cyclic process is quite good.The research result would be helpful for using SSPC as building material,especially as thermal insulation material.展开更多
基金This work was financially supported by the National Natural Science Foundation of China(Grant No.523712475,2072415 and 62101352)Shenzhen Science and Technology Program(RCBS20210706092343016).
文摘Despite the growing demand for transparent conductive films in smart and wearable electronics for electromagnetic interference(EMI)shielding,achieving a flexible EMI shielding film,while maintaining a high transmittance remains a significant challenge.Herein,a flexible,transparent,and conductive copper(Cu)metal mesh film for EMI shielding is fabricated by self-forming crackle template method and electroplating technique.The Cu mesh film shows an ultra-low sheet resistance(0.18Ω□^(-1)),high transmittance(85.8%@550 nm),and ultra-high figure of merit(>13,000).It also has satisfactory stretchability and mechanical stability,with a resistance increases of only 1.3%after 1,000 bending cycles.As a stretchable heater(ε>30%),the saturation temperature of the film can reach over 110°C within 60 s at 1.00 V applied voltage.Moreover,the metal mesh film exhibits outstanding average EMI shielding effectiveness of 40.4 dB in the X-band at the thickness of 2.5μm.As a demonstration,it is used as a transparent window for shielding the wireless communication electromagnetic waves.Therefore,the flexible and transparent conductive Cu mesh film proposed in this work provides a promising candidate for the next-generation EMI shielding applications.
基金supported by the National Natural Science Foundation of China(Grant nos.52371247,91963205,62101352,61988102 and 12274424)the National Key Research and Development Program of China(Grant nos.2019YFA0210200,2019YFA0210203,2022YFA1203500,and 2022YFA1206600).
文摘With the increasing demand for terahertz(THz)technology in security inspection,medical imaging,and flexible electronics,there is a significant need for stretchable and transparent THz electromagnetic interference(EMI)shielding materials.Existing EMI shielding materials,like opaque metals and carbon-based films,face challenges in achieving both high transparency and high shielding efficiency(SE).Here,a wrinkled structure strategy was proposed to construct ultra-thin,stretchable,and transparent terahertz shielding MXene films,which possesses both isotropous wrinkles(height about 50 nm)and periodic wrinkles(height about 500 nm).Compared to flat film,the wrinkled MXene film(8 nm)demonstrates a remarkable 36.5%increase in SE within the THz band.The wrinkled MXene film exhibits an EMI SE of 21.1 dB at the thickness of 100 nm,and an average EMI SE/t of 700 dBμm^(−1)over the 0.1-10 THz.Theoretical calculations suggest that the wrinkled structure enhances the film’s conductivity and surface plasmon resonances,resulting in an improved THz wave absorption.Additionally,the wrinkled structure enhances the MXene films’stretchability and stability.After bending and stretching(at 30%strain)cycles,the average THz transmittance of the wrinkled film is only 0.5%and 2.4%,respectively.The outstanding performances of the wrinkled MXene film make it a promising THz electromagnetic shielding materials for future smart windows and wearable electronics.
基金supported by the Chinese Police OfficeSichuan Police OfficeYunnan Police Office
文摘Previous studies have suggested that the incidence of post-traumatic stress disorder in earthquake rescue workers is relatively high. Risk factors for this disorder include demographic characteristics, earthquake-related high-risk factors, risk factors in the rescue process, personality, social support and coping style. This study examined the current status of a unit of 1 040 rescue workers who participated in earthquake relief for the Wenchuan earthquake that occurred on May 12th, 2008. Post-traumatic stress disorder was diagnosed primarily using the Clinician-Administered Post-traumatic Stress Disorder Scale during structured interviews. Univariate and multivariate sta-tistical analyses were used to examine major risk factors that contributed to the incidence of post-traumatic stress disorder. Results revealed that the incidence of this disorder in the rescue group was 5.96%. The impact factors in univariate analysis included death of family members, contact with corpses or witnessing of the deceased or seriously injured, near-death experience, severe injury or mental trauma in the rescue process and working at the epicenter of the earthquake. Correlation analysis suggested that post-traumatic stress disorder was positively correlated with psychotic and neurotic personalities, negative coping and low social support. Impact factors in mul-tivariate logistic regression analysis included near-death experience, severe injury or mental trauma, working in the epicenter of the rescue, neurotic personality, negative coping and low social support, among which low social support had the largest odds ratio of 20.42. Findings showed that the oc-currence of post-traumatic stress disorder was the result of the interaction of multiple factors.
基金National Natural Science Foundation of China,Grant/Award Number:52373175High-level Innovative Talents Foundation of Guizhou Province,Grant/Award Number:QKHPTRC-GCC[2023]024+3 种基金Science and Technology Innovation Team of Higher Education Department of Guizhou Province,Grant/Award Number:QJJ[2023]053Natural Science Foundation of Guizhou University,Grant/Award Number:GZUTGH[2023]12National Key Research and Development Program of China,Grant/Award Numbers:2022YFB3803300,2023YFE0116800Strategic Priority Research Program of Chinese Academy of Sciences,Grant/Award Number:XDB36000000。
文摘Organic solar cells(OSCs)have attracted much interest in the past few decades because of their advantages,such as being lightweight,low cost,simple preparation process,and environmental friendliness.While researchers have made significant progress on the active layer materials of OSCs,the interface engineering is another entry point for upgrading the photovoltaic performance of OSCs.Significantly,the interface modification materials,including anode interfacial materials and cathode interfacial materials,are two essential parts of interfacial layers for OSCs,in which the excellent interfacial materials can realize the very high-performance photovoltaic cells.Among these interfacial materials,the anode interfacial layers(AILs)play a crucial role in improving photovoltaic performance.This review expresses a detailed conclusion of the development of anode interfacial materials and an outlook on future trends for OSCs.
基金Supported by Beijing Hospitals Authority’Ascent Plan(DFL20191402)National Natural Science Foundation of China(82171671)+2 种基金Scientific Research Common Program of Beijing Municipal Commission of Education(KM202110025007)the National Key Research and Development Program of China(2016YFC1000304)Beijing Natural Science Foundation(7222248).
文摘What is already known about this topic?The level of molybdenum(Mo)in a mother’s urine has been linked to the growth rate of the fetus and the blood pressure levels in children.What is added by this report?We evaluated the variations in maternal plasma Mo concentrations throughout pregnancy and their potential association with the risk of spontaneous preterm birth(SPB).What are the implications for public health practice?Future research must determine the Mo levels in pregnant women across various regions in China.Moreover,particular attention needs to be given to the potential increase in Mo concentration throughout pregnancy and its possible adverse impacts on the health of both the mother and the fetus.
文摘Based on 14C dating and core sediments survey, phytolith records are employed to reconstruct paleovegetation and paleoclimate in the Jianghan Plain in the middle reach of the Yangtze River. Phytoliths identified are assigned into 21 well-described morphotypes and divided into four groups （Poaceae, fern, coniferous and broad-leaved）. The phytolith assemblages together with warmth index （Iw） are divided into 18 ecological zones, which reflect a complete vegetation history related to climate change in the middle reach of the Yangtze River during the past 15000 years. On the basis of the correlation ofphytolith records with the paleoclimatic indicators from stalagmite, peatland, North Atlantic deep-sea sediments, Loess Plateau of Central China, and Arabic Sea sediments, eight climatic phases are identified included Last Glacial Maximum （LGM） （20- 14.8 cal kaBP）, Last Deglaciation （LDG） （14.8-11.9 cal kaBP）, low-temperature phase in the Early Holocene （11.9-8 cal kaBP）, Holocene Opti- mum （8-4.9cal kaBP）, Holocene Katathermal （4.9- 1.1 cal kaBP）, Medieval Warmth Period （MWP） （1.1- 0.7 cal kaBP）, Little Ice Age （LIA） （0.7-0.15 cal kaBP）, and Modem Warming （0.15 cal kaBP-present）. Climatic events such as Bolling-Allerod warm intervals, Older Dryas, Inter-Allerod Cold Period, and Younger Dryas, and eight Holocene Bond events （B1-8） have been identified since the LDG. Our results demonstrate that the evolution of the climate in the research area has a strong link with the Indian Summer Monsoon （SW Monsoon）, Asian Summer Monsoon （SE Monsoon）, and Holocene events in North Atlantic simultaneously, which might indicate that solar variability affects the Earth surface climate system at the centennial and millennial scales.
基金Acknowledgements This work was supported by the National Basic Research Program of China （No. 2011CB808800）, the National Natural Science Foundation of China （Grant Nos. 40930210 and 41130207）, and the 111 Project of Education of Ministry of China （No. B08030）, and the MOST Special Fund from the State Key Laboratory of Geological Processes and Mineral Resources （MSFGPMR200804, MSFGPMR200904）. We thank Dr. Yang Pu and Miss Jun Cao for their help during samples preparation and experiments and two anonymous reviewers for comments on the manuscript.
文摘Lipids in stalagmites have been shown the potential for the paleoclimate reconstruction. However, the low lipid content leads to the difficulty in gaining high resolution lipid record in stalagmites because large mass of samples are required. Previous studies have validated that the acid digestion can improve the yield of lipids, especially fatty acids （FAs） and 3-hydroxy fatty acids （3- OH-FAs）. In order to obtain more content of FAs and 3- OH-FAs with limited stalagmite sample weight, we investigate here how the acid digestion conditions （HC1 concentration, heating temperature and time duration） could affect the yields of FAs and 3-OH-FAs. Under different concentration of HC1, from 2.0 to 6.0 mol/L, the FAs keep the same step in content variation with 3-OH- FAs, and the highest yields of both two appeared under the 3 mol/L HCl. The content of 3-OH-FAs increases posi- tively with the heating temperature from 80℃ to 150℃, while FAs showed the highest content at 130℃. Both of FAs and 3-OH-FAs firstly increased to a high content and then decreased as the heating time duration varies from 1.0 to 4.0 h, with the highest yields of both two being at 3.0 h. Consequently, we suggest the optimized acid digestion condition is under 3 mol/L HC1, heating at 130℃ for 3 h and 5 g of each stalagmite sample are sufficient for the lipid analysis.
基金financially supported by the National Natural Science Foundation of China (grant no.52072415)Guangdong Basic and Applied Basic Research Foundation (grant nos.2021A1515012387,and 2021A1515110980)。
文摘Owing to the conductance-adjustable performance,the emerging two-terminal memristors are promising candidates for artificial synapses and brain-spired neuromorphic computing.Although memristors based on molybdenum disulfide(MoS_(2))have displayed outstanding performance,such as thermal stability and high energy efficiency,reports on memristors based on MoS_(2) as the functional layer to simulate synaptic behavior are limited.Herein,a homologous Mo_(2)C/MoS_(2)-based memristor is prepared by partially sulfuring two-dimensional Mo_(2)C crystal.The memristor shows good stability,excellent retention(~104 s)and endurance(>100 cycles),and a high ON/OFF ratio(>10^(3)).Moreover,for comprehensively mimicking biological synapses,the essential synaptic functions of the device are systematically analyzed,including paired-pulse facilitation(PPF),short-term plasticity(STP),long-term plasticity(LTP),long-term depression(LTD),and the transitions from STP to LTP.Notably,this artificial synapse could keep a highlevel stable memory for a long time(60 s)after repeated stimulation.These results prove that our device is highly desirable for biological synapses,which show great potential for application in future high-density storage and neuromorphic computing systems.
基金supported by the National Natural Science Foundation of China(41825019,42130208,41821001,and 42102343)the Programme of Introducing Talents of Discipline to Universities(BP0820004)+1 种基金China Postdoctoral Science Foundation(2020M682515)an award from “Laboratoire Excellence”LabexMER(ANR-10-LABX-19)。
文摘The Ediacaran Period(~635–539 Ma)was a critical time in Earth history due to large increases in atmospheric and oceanic oxygen levels and rapid evolution of early animals[1].It was also an interval of major climatic and geochemical perturbations,such as the~580-Ma Gaskiers Glaciation[2](Fig.S1 online)and the late Ediacaran Shuram Excursion(SE;also known as DOUNCE or EN3 in South China,see Fig.S2 online),which was the largest negative carbonate carbon isotope(δ13Ccarb)excursion in Earth history[3,4].In contrast to established redox,biological,and C-cycling records for the Ediacaran,however,no secular,high-resolution paleotemperature record with climatic significance has been reported to date,impeding our understanding of the relationships among major environmental,biological,geochemical,and climatic processes and milestones.
基金supported by 2024 Beijing Forestry University Student Innovation and Entrepreneurship Training Program(Grant Number:X202410022059).
文摘The use of bio-based biomass construction materials has the advantage of helping to reduce fossil energy demand,protecting the environment from carbon dioxide emission and reducing the production of non-degradable waste.This paper used resin-modified soy protein(SP)adhesive to combine rice straw stalks,and made straw-soy protein composites(SSPC)material.The physical properties,compressive behavior and stability during wetting drying cycles of SSPC were measured.Due to water evaporation,the SP matrix is full of connected pores,resulting to its physical properties of small density,high shrinkage ratio and low thermal conductivity,which are 0.24 g/cm^(3),16.2%,and 0.065 W/(m•K),respectively.Adding straw is helpful to the physical properties of SP matrix,leading to an obvious decrease in shrinkage ratio and thermal conductivity of SSPC,which are 8.51%and 0.075 W/m•K.Furthermore,the compressive load-displacement curves of SSPC groups divide into two types:divergent and convergent.The compressive strength of divergent samples is decided by the critical displacement determined according to the convergent specimens.It shows that straw stalk proves the positive effect on the compressive property of SP matrix.As to the mass of SSPC samples during the wetting drying cycles,it drops apparently in the initial three cycles,and becomes negligible from the fifth cycle,meaning that the stability of SSPC during wetting drying cyclic process is quite good.The research result would be helpful for using SSPC as building material,especially as thermal insulation material.
