Structural shape monitoring plays a vital role in the structural health monitoring systems.The inverse finite element method(iFEM)has been demonstrated to be a practical method of deformation reconstruction owing to i...Structural shape monitoring plays a vital role in the structural health monitoring systems.The inverse finite element method(iFEM)has been demonstrated to be a practical method of deformation reconstruction owing to its unique advantages.Current iFEM formulations have been applied to small deformation of structures based on the small-displacement assumption of linear theory.However,this assumption may be inapplicable to some structures with large displacements in practical applications.Therefore,geometric nonlinearity needs to be considered.In this study,to expand the practical utility of iFEM for large displacement monitoring,we propose a nonlinear iFEM algorithm based on a four-node inverse quadrilateral shell element iQS4.Taking the advantage of an iterative iFEM algorithm,a nonlinear response is linearized to compute the geometrically nonlinear deformation reconstruction,like the basic concept of nonlinear FE analysis.Several examples are solved to verify the proposed approach.It is demonstrated that large displacements can be accurately estimated even if the in-situ sensor data includes different levels of randomly generated noise.It is proven that the nonlinear iFEM algorithm provides a more accurate displacement response as compared to the linear iFEM methodology for structures undergoing large displacement.Hence,the proposed approach can be utilized as a viable tool to effectively characterize geometrically nonlinear deformations of structures in real-time applications.展开更多
Excess molar enthalpies,H^E,for the binary mixtures of 2-pentanol with n-alkanes(n-heptane,n-octane,and nnonane)have been determined at three different temperatures T=(293.15,298.15 and 303.15)K and normal atmospheric...Excess molar enthalpies,H^E,for the binary mixtures of 2-pentanol with n-alkanes(n-heptane,n-octane,and nnonane)have been determined at three different temperatures T=(293.15,298.15 and 303.15)K and normal atmospheric pressure over the entire composition range using a Calvet microcalorimeter.All mixtures show endothermic mixing with the maximum values of the excess enthalpies occurring in the n-alkane-rich region.The H^Edata are smoothed using Redlich–Kister equation.The applicability of the Treszczanowicz–Benson,ERAS,Renon–Prausnitz and Chen–Bagley models to correlate H^Eof studied mixtures is tested,and the agreement between experimental and theoretical results is satisfactory.Each model includes a self-association equilibrium constant that represents hydrogen bonding and an adjustable parameter that reflects physical interactions.展开更多
This study proposed a damage identification method compared with the existing ones,based on relative curvature difference and frequency perturbation theory,showing sensitivity to local damage by changes in the curvatu...This study proposed a damage identification method compared with the existing ones,based on relative curvature difference and frequency perturbation theory,showing sensitivity to local damage by changes in the curvature mode and high recognition accuracy of frequencies.Considering the relative curvature difference as a damage index,numerical simulation is used for a simply supported beam under single and multiple damage conditions for different damage degrees.The damage is located according to the curvature mode curves,and the damage degree is qualitatively determined.Based on the perturbation theory,the damage equations are established by the changes between frequencies before and after damage,and the damage localization and degree are verified and determined.Effectiveness of the proposed method for identifying damage at different conditions is numerically investigated.This method potentially promotes the development of damage identification of beam structures.展开更多
To guarantee the blue skies for the 2022 Winter Olympics held in Beijing and Zhangjiakou from February 4 to 20,Beijing and its surrounding areas adopted a series of emission control measures.This provides an opportuni...To guarantee the blue skies for the 2022 Winter Olympics held in Beijing and Zhangjiakou from February 4 to 20,Beijing and its surrounding areas adopted a series of emission control measures.This provides an opportunity to determine the impacts of large-scale temporary control measures on the air quality in Beijing during this special period.Here,we applied the WRF-CMAQ model to quantify the contributions of emission reduction measures and meteorological conditions.Results show that meteorological conditions in 2022 decreased PM_(2.5)in Beijing by 6.9 and 11.8μg/m^(3)relative to 2021 under the scenarios with and without emission reductions,respectively.Strict emission reduction measures implemented in Beijing and seven neighboring provinces resulted in an average decrease of 13.0μg/m^(3)(-41.2%)in PM_(2.5)in Beijing.Over the entire period,local emission reductions contributed more to good air quality in Beijing than nonlocal emission reductions.Under the emission reduction scenario,local,controlled regions,other regions,and boundary conditions contributed 47.7%,42.0%,5.3%,and 5.0%to the PM_(2.5)concentrations in Beijing,respectively.The results indicate that during the cleaning period with the air masses from the northwest,the abatements of PM_(2.5)were mainly caused by local emission reductions.However,during the potential pollution period with the air masses from the east-northeast and west-southwest,the abatements of PM_(2.5)were caused by both local and nonlocal emission reductions almost equally.This implies that regional coordinated prevention and control strategies need to be arranged scientifically and rationally when heavy pollution events are forecasted.展开更多
In this paper, to investigate the influence of soil inhomogeneity on the bending of circular thinplates on elastic foundations, the static problem of circular thin plates on Gibson elasticfoundation is solved using an...In this paper, to investigate the influence of soil inhomogeneity on the bending of circular thinplates on elastic foundations, the static problem of circular thin plates on Gibson elasticfoundation is solved using an iterative method based on the modified Vlasov model. On the basisof the principle of minimum potential energy, the governing differential equations and boundaryconditions for circular thin plates on modified Vlasov foundation considering the characteristics ofGibson soil are derived. The equations for the attenuation parameter in bending problem are alsoobtained, and the issue of unknown parameters being difficult to determine is solved using theiterative method. Numerical examples are analyzed and the results are in good agreement withthose form other literatures. It proves that the method is practical and accurate. Theinhomogeneity of modified Vlasov foundations has some influence on the deformation andinternal force behavior of circular thin plates. The effects of various parameters on the bending ofcircular plates and characteristic parameters of the foundation are discussed. The modified modelfurther enriches and develops the elastic foundations. Relevant conclusions that are meaningful toengineering practice are drawn.展开更多
In this work, Bi2XO6(X = W, Mo) are synthesized at different temperatures. The results of tests find the optimal temperatures of Bi_(2)WO_(6) and Bi_(2)MoO_(6) are 180 and 160 °C(BW-180, BM-160). Then, BW-180 and...In this work, Bi2XO6(X = W, Mo) are synthesized at different temperatures. The results of tests find the optimal temperatures of Bi_(2)WO_(6) and Bi_(2)MoO_(6) are 180 and 160 °C(BW-180, BM-160). Then, BW-180 and BM-160 are further compounded with different contents of CuS. The results of photoelectrochemical(PEC) tests show that CuS can improve the PEC performance of semiconductor materials, and it has better performance when CuS mass fraction is 5%. These maybe the photoelectron potentials generated by Cu S/Bi_(2)XO_(6)(X = Mo, W) heterojunction reduce the combination of photogenerated electrons and holes. When the PEC sensor based on 5%-CuS/BW-180 detects Cr(VI), it has a linear range of 1–80 μmol/L with detection limit of 0.95 μmol/L, while the PEC sensor based on 5%-CuS/BM-160 detects Cr(VI) has a linear range of 0.5–230 μmol/L and a detection limit of 0.12 μmol/L. Thus, 5%-CuS/Bi_(2)XO_(6) has potential application in hexavalent chromium detection.展开更多
Convective cooling by wind is crucial for large-scale photovoltaic(PV)systems,as power generation inversely correlates with panel temperature.Therefore,accurately determining the convective heat transfer coefficient f...Convective cooling by wind is crucial for large-scale photovoltaic(PV)systems,as power generation inversely correlates with panel temperature.Therefore,accurately determining the convective heat transfer coefficient for PV arrays with various geometric configurations is essential to optimize array design.Traditional methods to quantify the effects of configuration utilize either Computational Fluid Dynamics(CFD)simulations or empirical methods.These approaches often face challenges due to high computational demands or limited accuracy,particularly with complex array configurations.Machine learning approaches,especially hybrid learning models,have emerged as effective tools to address challenges in heat transfer design optimization.This study introduces a method that combines Physics-Informed Machine Learning with a Deep Convolutional Neural Network(PIML-DCNN)to predict convective heat transfer rates with high accuracy and computational efficiency.Additionally,an innovative loss function,termed the“Pocket Loss”,is developed to enhance the interpretability and robustness of the PIML-DCNN model.The proposed model achieves relative estimation errors of 2.5%and 2.7%on the validation and test datasets,respectively,when benchmarked against comprehensive CFD simulations.These results highlight the potential of the proposed model to efficiently guide the configuration design of PV arrays,thereby enhancing power generation in real-world operations.展开更多
Dear Editor,Maize(Zea mays L.)is one of the most widely cultivated crops worldwide(Ranum et al.,2014),accounting for about 37.2%of the global cereal crop production.Maize production yield has increased over sevenfold ...Dear Editor,Maize(Zea mays L.)is one of the most widely cultivated crops worldwide(Ranum et al.,2014),accounting for about 37.2%of the global cereal crop production.Maize production yield has increased over sevenfold since single-cross maize hybrids were deployed in the beginning of the last century(Andorf et al.,2019).展开更多
Dear Editor,Exaptation is defined as characters evolved for other usages(or for no function at all)and later“coopted”for their current role(Gould and Vrba,1982).Exaptation has occurred in many organisms,sometimes as...Dear Editor,Exaptation is defined as characters evolved for other usages(or for no function at all)and later“coopted”for their current role(Gould and Vrba,1982).Exaptation has occurred in many organisms,sometimes as an outcome of organ specialization for adaptation.This process is exemplified in the family Triglidae,commonly known as gurnards or sea robins.展开更多
Background:Elimination of hepatitis B virus(HBV)is a striking challenge for countries with high or moderate disease burden.Therefore,using China as a practical case to share experiences for similar countries may accel...Background:Elimination of hepatitis B virus(HBV)is a striking challenge for countries with high or moderate disease burden.Therefore,using China as a practical case to share experiences for similar countries may accelerate the achievement of the WHO 2030 target of 90%reduction in HBV-related incidence.We aim to evaluate the impact of national HBV immunization strategies in China;and the feasibility to achieve WHO 2030 targets under diferent scenarios.Methods:We constructed an expanded Susceptible-Exposed-Infectious-Recovered(SEIR)model and decision treeMarkov model to estimate the epidemic of HBV in China,assess the feasibility of 2030 Elimination Goals through the projections and conduct the economic analysis.Least square method was used to calibrate the expanded SEIR model by yearly data of laboratory-confrmed HBV cases from 1990 to 2018.Two models were separately used to evaluate the impact and cost-efectiveness of HBV vaccine by comparing prevalence of chronic HBV infections,qualityadjusted life-years(QALYs),incremental cost efectiveness ratio and beneft–cost ratio(BCR)under various intervention options,providing a basis for exploring new containment strategies.Results:Between 1990 and 2020,the number of chronic HBV infections decreased by 33.9%.The current status quo would lead to 55.73 million infections(3.95%prevalence)in 2030,compared to 90.63 million(6.42%prevalence)of the“Without the NIP”scenario(NIP:National Immunization Program),114.78 million(8.13%prevalence)without any interventions.The prevention of mother to child transmission(PMTCT)strategy showed a net beneft as 12,283.50 dollars per person,with BCR as 12.66,which is higher than that of universal vaccination at 9.49.Compared with no screening and no vaccination,the PMTCT strategy could save 7726.03 dollars for each QALY increase.Conclusions:Our fndings proved the HBV vaccination has demonstrated a substantial positive impact on controlling the epidemic of HBV in terms of efectiveness and economy after about 30 years of implementation of the national hepatitis B immunization program which also provided containment experience for high or medium burden countries.As for China,the next step should focus on exploring strategies to improve diagnosis and treatment coverage to reduce the burden of HBV-related deaths and ultimately eliminate HBV.展开更多
Overuse of fossil fuels led to energy crises and pollution.Thus,alternative energy sources are needed.Hydrogen,with its clean and high-density traits,is seen as a future energy carrier.Producing hydrogen from electric...Overuse of fossil fuels led to energy crises and pollution.Thus,alternative energy sources are needed.Hydrogen,with its clean and high-density traits,is seen as a future energy carrier.Producing hydrogen from electricity can store renewable energy for a sustainable hydrogen economy.While much research on water electrolysis hydrogen production systems exists,comprehensive reviews of engineering applications are scarce.This review sums up progress and improvement strategies of common water electrolysis technologies(alkaline water electrolysis,proton exchange membrane water electrolysis,solid oxide water electrolysis,and anion exchange membrane water electrolysis,etc.),including component and material research and development.It also reviews these technologies by development and maturity,especially their engineering applications,discussing features and prospects.Bottlenecks of different technologies are compared and analyzed,and future directions are summarized.The aim is to link academic material research with industrial manufacturing.展开更多
Solar nowcasting over the 0–4-h horizon is essential to the intra-day scheduling of power systems with high solar penetration.It is,now,widely acknowledged that methods leveraging the geostationary weather satellite ...Solar nowcasting over the 0–4-h horizon is essential to the intra-day scheduling of power systems with high solar penetration.It is,now,widely acknowledged that methods leveraging the geostationary weather satellite data are the most promising options,for such data is able to offer spatio-temporal information that is absolutely vital to capturing the variability of irradiance and thus solar power.Satellite-based irradiance nowcasting takes three general steps:(1)irradiance retrieval from the top-of-the-atmosphere reflectance images,(2)time-forward advection of the irradiance field,and(3)post-processing the forecasts.Since nowcasting applications demand some irradiance retrieval techniques that are computationally light,semi-empirical algorithms such as Heliosat-2 are often favored.On the other hand,optical flow,contrasting other means of acquiring the cloud motion vectors,is commonly regarded as more competitive.On this point,this study presents a concise technical review of several fundamental optical flow algorithms and demonstrates them,with data from Fengyun-4A,which is China's latest-generation geostationary weather satellite that has hitherto been somewhat under-utilized for solar energy meteorology.Using high-quality measurements from a research-grade radiometric station as verifications,it is found that the 0–4-h nowcasting yields 19.5%–26.7%and 42.4%–53.2%nRMSEs for global horizontal irradiance and beam normal irradiance,respectively,outperforming previous results obtained with Fengyun-4A.Furthermore,ensemble optical flow,which acts as a form of post-processing,is emphasized,as combining the outcomes generated by several peers can shrink the forecast errors of the two irradiance components by 2.2%and 3.0%.展开更多
Owing to the robust scalability,ease of control and substantial industrial applications,the utilization of electrospinning technology to produce piezoelectric nanofiber materials demonstrates a significant potential i...Owing to the robust scalability,ease of control and substantial industrial applications,the utilization of electrospinning technology to produce piezoelectric nanofiber materials demonstrates a significant potential in the development of wearable products including flexible wearable sensors.However,it is unfortunate that the attainment of high-performance piezoelec-tric materials through this method remains a challenging task.Herein,a high-performance composite nanofiber membrane with a coherent and uniformly dispersed two-dimensional network topology composed of polyvinylidene fluoride(PVDF)/dopamine(DA)nanofiber membranes and ultrafine PVDF/DA nanofibers was successfully fabricated by the electrospinning technique.Based on the evidence obtained from simulations,experimental and theoretical results,it was confirmed that the unique structure of the nanofiber membrane significantly enhances the piezoelectric performance.The present PVDF/DA composite nanofibers demonstrated a remarkable piezoelectric performance such as a wide response range(1.5–40 N),high sensitivity to weak forces(0–4 N,7.29 V N^(-1)),and outstanding operational durability.Furthermore,the potential application of the present PVDF/DA membrane as a flexible wearable sensor for monitoring human motion and subtle physiological signals has also been validated.This work not only introduces a novel strategy for the application of electrospun nanofibers in sensors but also provides new insights into high-performance piezoelectric materials.展开更多
基金supported by the NationalNatural Science Foundation of China(Grant No.11902253)the Fundamental Research Funds for the Central Universities of China.The authors are grateful for this support.
文摘Structural shape monitoring plays a vital role in the structural health monitoring systems.The inverse finite element method(iFEM)has been demonstrated to be a practical method of deformation reconstruction owing to its unique advantages.Current iFEM formulations have been applied to small deformation of structures based on the small-displacement assumption of linear theory.However,this assumption may be inapplicable to some structures with large displacements in practical applications.Therefore,geometric nonlinearity needs to be considered.In this study,to expand the practical utility of iFEM for large displacement monitoring,we propose a nonlinear iFEM algorithm based on a four-node inverse quadrilateral shell element iQS4.Taking the advantage of an iterative iFEM algorithm,a nonlinear response is linearized to compute the geometrically nonlinear deformation reconstruction,like the basic concept of nonlinear FE analysis.Several examples are solved to verify the proposed approach.It is demonstrated that large displacements can be accurately estimated even if the in-situ sensor data includes different levels of randomly generated noise.It is proven that the nonlinear iFEM algorithm provides a more accurate displacement response as compared to the linear iFEM methodology for structures undergoing large displacement.Hence,the proposed approach can be utilized as a viable tool to effectively characterize geometrically nonlinear deformations of structures in real-time applications.
文摘Excess molar enthalpies,H^E,for the binary mixtures of 2-pentanol with n-alkanes(n-heptane,n-octane,and nnonane)have been determined at three different temperatures T=(293.15,298.15 and 303.15)K and normal atmospheric pressure over the entire composition range using a Calvet microcalorimeter.All mixtures show endothermic mixing with the maximum values of the excess enthalpies occurring in the n-alkane-rich region.The H^Edata are smoothed using Redlich–Kister equation.The applicability of the Treszczanowicz–Benson,ERAS,Renon–Prausnitz and Chen–Bagley models to correlate H^Eof studied mixtures is tested,and the agreement between experimental and theoretical results is satisfactory.Each model includes a self-association equilibrium constant that represents hydrogen bonding and an adjustable parameter that reflects physical interactions.
基金supported by the National Natural Science Foundation of China under Grant No.51278420the Natural Science Foundation of Shaanxi Province under Grant No.2017JM5021.
文摘This study proposed a damage identification method compared with the existing ones,based on relative curvature difference and frequency perturbation theory,showing sensitivity to local damage by changes in the curvature mode and high recognition accuracy of frequencies.Considering the relative curvature difference as a damage index,numerical simulation is used for a simply supported beam under single and multiple damage conditions for different damage degrees.The damage is located according to the curvature mode curves,and the damage degree is qualitatively determined.Based on the perturbation theory,the damage equations are established by the changes between frequencies before and after damage,and the damage localization and degree are verified and determined.Effectiveness of the proposed method for identifying damage at different conditions is numerically investigated.This method potentially promotes the development of damage identification of beam structures.
基金supported by the National Natural Science Foundation of China (Nos.42175084,21577126,and 41561144004)the Department of Science and Technology of China (Nos.2018YFC0213506,2018YFC0213503,and 2016YFC0202702)+4 种基金the National Research Program for Key Issues in Air Pollution Control in China (No.DQGG0107)supported by the“Zhejiang 1000 Talent Plan”and Research Center for Air Pollution and Health in Zhejiang UniversityPengfei Li is supported by the National Natural Science Foundation of China (No.22006030)the Initiation Fund for Introducing Talents of Hebei Agricultural University (No.412201904)the Hebei Youth Top Q15 Fund (No.BJ2020032)。
文摘To guarantee the blue skies for the 2022 Winter Olympics held in Beijing and Zhangjiakou from February 4 to 20,Beijing and its surrounding areas adopted a series of emission control measures.This provides an opportunity to determine the impacts of large-scale temporary control measures on the air quality in Beijing during this special period.Here,we applied the WRF-CMAQ model to quantify the contributions of emission reduction measures and meteorological conditions.Results show that meteorological conditions in 2022 decreased PM_(2.5)in Beijing by 6.9 and 11.8μg/m^(3)relative to 2021 under the scenarios with and without emission reductions,respectively.Strict emission reduction measures implemented in Beijing and seven neighboring provinces resulted in an average decrease of 13.0μg/m^(3)(-41.2%)in PM_(2.5)in Beijing.Over the entire period,local emission reductions contributed more to good air quality in Beijing than nonlocal emission reductions.Under the emission reduction scenario,local,controlled regions,other regions,and boundary conditions contributed 47.7%,42.0%,5.3%,and 5.0%to the PM_(2.5)concentrations in Beijing,respectively.The results indicate that during the cleaning period with the air masses from the northwest,the abatements of PM_(2.5)were mainly caused by local emission reductions.However,during the potential pollution period with the air masses from the east-northeast and west-southwest,the abatements of PM_(2.5)were caused by both local and nonlocal emission reductions almost equally.This implies that regional coordinated prevention and control strategies need to be arranged scientifically and rationally when heavy pollution events are forecasted.
基金financially supported by the National Natural Science Foundation of China (Grant 51278420)the Natural Science Foundation of Shaanxi Province (Grant 2017JM5021)
文摘In this paper, to investigate the influence of soil inhomogeneity on the bending of circular thinplates on elastic foundations, the static problem of circular thin plates on Gibson elasticfoundation is solved using an iterative method based on the modified Vlasov model. On the basisof the principle of minimum potential energy, the governing differential equations and boundaryconditions for circular thin plates on modified Vlasov foundation considering the characteristics ofGibson soil are derived. The equations for the attenuation parameter in bending problem are alsoobtained, and the issue of unknown parameters being difficult to determine is solved using theiterative method. Numerical examples are analyzed and the results are in good agreement withthose form other literatures. It proves that the method is practical and accurate. Theinhomogeneity of modified Vlasov foundations has some influence on the deformation andinternal force behavior of circular thin plates. The effects of various parameters on the bending ofcircular plates and characteristic parameters of the foundation are discussed. The modified modelfurther enriches and develops the elastic foundations. Relevant conclusions that are meaningful toengineering practice are drawn.
基金financial support from the National Natural Science Foundation of China(Nos.21205030,2198073 and NSFC-U1903217)by the key project of Hubei provincial education department(No.D20171001)Key Laboratory of regional development and environmental response in Hubei Province(No.2019(0A)003)。
文摘In this work, Bi2XO6(X = W, Mo) are synthesized at different temperatures. The results of tests find the optimal temperatures of Bi_(2)WO_(6) and Bi_(2)MoO_(6) are 180 and 160 °C(BW-180, BM-160). Then, BW-180 and BM-160 are further compounded with different contents of CuS. The results of photoelectrochemical(PEC) tests show that CuS can improve the PEC performance of semiconductor materials, and it has better performance when CuS mass fraction is 5%. These maybe the photoelectron potentials generated by Cu S/Bi_(2)XO_(6)(X = Mo, W) heterojunction reduce the combination of photogenerated electrons and holes. When the PEC sensor based on 5%-CuS/BW-180 detects Cr(VI), it has a linear range of 1–80 μmol/L with detection limit of 0.95 μmol/L, while the PEC sensor based on 5%-CuS/BM-160 detects Cr(VI) has a linear range of 0.5–230 μmol/L and a detection limit of 0.12 μmol/L. Thus, 5%-CuS/Bi_(2)XO_(6) has potential application in hexavalent chromium detection.
基金supported by the Research Grants Council of the Hong Kong Special Administrative Region,China(Project No.C6003-22Y)supported by the Hong Kong Polytechnic University Undergraduate Research and Innovation Scheme(Project No.P0043659).
文摘Convective cooling by wind is crucial for large-scale photovoltaic(PV)systems,as power generation inversely correlates with panel temperature.Therefore,accurately determining the convective heat transfer coefficient for PV arrays with various geometric configurations is essential to optimize array design.Traditional methods to quantify the effects of configuration utilize either Computational Fluid Dynamics(CFD)simulations or empirical methods.These approaches often face challenges due to high computational demands or limited accuracy,particularly with complex array configurations.Machine learning approaches,especially hybrid learning models,have emerged as effective tools to address challenges in heat transfer design optimization.This study introduces a method that combines Physics-Informed Machine Learning with a Deep Convolutional Neural Network(PIML-DCNN)to predict convective heat transfer rates with high accuracy and computational efficiency.Additionally,an innovative loss function,termed the“Pocket Loss”,is developed to enhance the interpretability and robustness of the PIML-DCNN model.The proposed model achieves relative estimation errors of 2.5%and 2.7%on the validation and test datasets,respectively,when benchmarked against comprehensive CFD simulations.These results highlight the potential of the proposed model to efficiently guide the configuration design of PV arrays,thereby enhancing power generation in real-world operations.
基金supported by the National Natural Science Foundation of China(32361143514,32272190)Nanfan Special Project+2 种基金Chinese Academy of Agricultural Sciences(YBXM2407)Alibaba FoundationInnovation Program of Chinese Academy of Agricultural Sciences(CAAS-CSIAF202303)。
文摘Dear Editor,Maize(Zea mays L.)is one of the most widely cultivated crops worldwide(Ranum et al.,2014),accounting for about 37.2%of the global cereal crop production.Maize production yield has increased over sevenfold since single-cross maize hybrids were deployed in the beginning of the last century(Andorf et al.,2019).
基金supported by the National Key Research and development Program of China(2022YFC3400300)the National Natural Science Foundation of China(32122021,32370452,32100367)+3 种基金the Postdoctoral Fellowship Program of CPSF(GZC20233518)the Fundamental Research Funds for the Central Universities(G2022KY05107)NWPU Scientific Research Initiation Grant(23GH02027)the Financial Fund of the Ministry of Agriculture and Rural Affairs,China(125C0505)。
文摘Dear Editor,Exaptation is defined as characters evolved for other usages(or for no function at all)and later“coopted”for their current role(Gould and Vrba,1982).Exaptation has occurred in many organisms,sometimes as an outcome of organ specialization for adaptation.This process is exemplified in the family Triglidae,commonly known as gurnards or sea robins.
文摘Background:Elimination of hepatitis B virus(HBV)is a striking challenge for countries with high or moderate disease burden.Therefore,using China as a practical case to share experiences for similar countries may accelerate the achievement of the WHO 2030 target of 90%reduction in HBV-related incidence.We aim to evaluate the impact of national HBV immunization strategies in China;and the feasibility to achieve WHO 2030 targets under diferent scenarios.Methods:We constructed an expanded Susceptible-Exposed-Infectious-Recovered(SEIR)model and decision treeMarkov model to estimate the epidemic of HBV in China,assess the feasibility of 2030 Elimination Goals through the projections and conduct the economic analysis.Least square method was used to calibrate the expanded SEIR model by yearly data of laboratory-confrmed HBV cases from 1990 to 2018.Two models were separately used to evaluate the impact and cost-efectiveness of HBV vaccine by comparing prevalence of chronic HBV infections,qualityadjusted life-years(QALYs),incremental cost efectiveness ratio and beneft–cost ratio(BCR)under various intervention options,providing a basis for exploring new containment strategies.Results:Between 1990 and 2020,the number of chronic HBV infections decreased by 33.9%.The current status quo would lead to 55.73 million infections(3.95%prevalence)in 2030,compared to 90.63 million(6.42%prevalence)of the“Without the NIP”scenario(NIP:National Immunization Program),114.78 million(8.13%prevalence)without any interventions.The prevention of mother to child transmission(PMTCT)strategy showed a net beneft as 12,283.50 dollars per person,with BCR as 12.66,which is higher than that of universal vaccination at 9.49.Compared with no screening and no vaccination,the PMTCT strategy could save 7726.03 dollars for each QALY increase.Conclusions:Our fndings proved the HBV vaccination has demonstrated a substantial positive impact on controlling the epidemic of HBV in terms of efectiveness and economy after about 30 years of implementation of the national hepatitis B immunization program which also provided containment experience for high or medium burden countries.As for China,the next step should focus on exploring strategies to improve diagnosis and treatment coverage to reduce the burden of HBV-related deaths and ultimately eliminate HBV.
基金the National Natural Science Foundation of China(Grant No.22478423)for the support.
文摘Overuse of fossil fuels led to energy crises and pollution.Thus,alternative energy sources are needed.Hydrogen,with its clean and high-density traits,is seen as a future energy carrier.Producing hydrogen from electricity can store renewable energy for a sustainable hydrogen economy.While much research on water electrolysis hydrogen production systems exists,comprehensive reviews of engineering applications are scarce.This review sums up progress and improvement strategies of common water electrolysis technologies(alkaline water electrolysis,proton exchange membrane water electrolysis,solid oxide water electrolysis,and anion exchange membrane water electrolysis,etc.),including component and material research and development.It also reviews these technologies by development and maturity,especially their engineering applications,discussing features and prospects.Bottlenecks of different technologies are compared and analyzed,and future directions are summarized.The aim is to link academic material research with industrial manufacturing.
基金supported by the National NaturalScience Foundation of China(Grant Nos.42375192,52406230)the China Meteorological Administration Climate Change Special Program(GrantNo.QBZ202315)+2 种基金the China Postdoctoral Science Foundation(Grant No.2023M740908)the National Key Research and Development Program of China(Grant No.2024YFF0809202)the Key Research and Development and Achievement Transformation Program of Inner Mongolia Autonomous Region(Grant No.2025YFDZ0014)。
文摘Solar nowcasting over the 0–4-h horizon is essential to the intra-day scheduling of power systems with high solar penetration.It is,now,widely acknowledged that methods leveraging the geostationary weather satellite data are the most promising options,for such data is able to offer spatio-temporal information that is absolutely vital to capturing the variability of irradiance and thus solar power.Satellite-based irradiance nowcasting takes three general steps:(1)irradiance retrieval from the top-of-the-atmosphere reflectance images,(2)time-forward advection of the irradiance field,and(3)post-processing the forecasts.Since nowcasting applications demand some irradiance retrieval techniques that are computationally light,semi-empirical algorithms such as Heliosat-2 are often favored.On the other hand,optical flow,contrasting other means of acquiring the cloud motion vectors,is commonly regarded as more competitive.On this point,this study presents a concise technical review of several fundamental optical flow algorithms and demonstrates them,with data from Fengyun-4A,which is China's latest-generation geostationary weather satellite that has hitherto been somewhat under-utilized for solar energy meteorology.Using high-quality measurements from a research-grade radiometric station as verifications,it is found that the 0–4-h nowcasting yields 19.5%–26.7%and 42.4%–53.2%nRMSEs for global horizontal irradiance and beam normal irradiance,respectively,outperforming previous results obtained with Fengyun-4A.Furthermore,ensemble optical flow,which acts as a form of post-processing,is emphasized,as combining the outcomes generated by several peers can shrink the forecast errors of the two irradiance components by 2.2%and 3.0%.
基金supported by JST SPRING,Grant Number JPMJSP2144(Shinshu University).
文摘Owing to the robust scalability,ease of control and substantial industrial applications,the utilization of electrospinning technology to produce piezoelectric nanofiber materials demonstrates a significant potential in the development of wearable products including flexible wearable sensors.However,it is unfortunate that the attainment of high-performance piezoelec-tric materials through this method remains a challenging task.Herein,a high-performance composite nanofiber membrane with a coherent and uniformly dispersed two-dimensional network topology composed of polyvinylidene fluoride(PVDF)/dopamine(DA)nanofiber membranes and ultrafine PVDF/DA nanofibers was successfully fabricated by the electrospinning technique.Based on the evidence obtained from simulations,experimental and theoretical results,it was confirmed that the unique structure of the nanofiber membrane significantly enhances the piezoelectric performance.The present PVDF/DA composite nanofibers demonstrated a remarkable piezoelectric performance such as a wide response range(1.5–40 N),high sensitivity to weak forces(0–4 N,7.29 V N^(-1)),and outstanding operational durability.Furthermore,the potential application of the present PVDF/DA membrane as a flexible wearable sensor for monitoring human motion and subtle physiological signals has also been validated.This work not only introduces a novel strategy for the application of electrospun nanofibers in sensors but also provides new insights into high-performance piezoelectric materials.
