近年来,气候变化和人类干扰活动导致生态系统服务退化,严重限制区域可持续性发展。科学认知生态系统服务变化特征及其驱动机制是制定区域可持续发展和提升生态安全保障政策的基础和前提。本研究以吉林西部为研究区,运用InVEST(Integrate...近年来,气候变化和人类干扰活动导致生态系统服务退化,严重限制区域可持续性发展。科学认知生态系统服务变化特征及其驱动机制是制定区域可持续发展和提升生态安全保障政策的基础和前提。本研究以吉林西部为研究区,运用InVEST(Integrated Valuation of Ecosystem Services and Tradeoffs Tools)模型定量评估了近10年(2010-2020年)吉林西部生态系统服务(产水量、土壤保持和生境质量),分析其时空变化特征,并揭示气候变化和土地利用/覆盖变化(LUCC)及其交互作用对生态系统服务变化的相对影响。结果表明:近10年,(1)在土地管理政策的驱动下,旱地、湿地和未利用地的面积减少,而水田、林地、草地和建设用地的面积呈增长趋势,其中减少的旱地主要转化为水田或林地。(2)近10年吉林西部生态系统服务总体呈增长趋势,且存在显著空间异质性;产水量和土壤保持量分别增加24.2%、51.6%,产水量增幅主要分布于中部和西北部的湿地和水田,土壤保持量增加区域主要位于西部和东北部的湿地和草地,而生境质量总体呈现下降趋势(-4.8%)。(3)近10年,产水量增加主要受气候变化(温度升高、降水增加)的正向影响,土壤保持量增加主要受气候变化及其与LUCC(植被覆盖增加)交互作用的影响,生境质量的下降主要由耕地面积增加和城市扩张等LUCC的负向影响。本研究结果可为吉林西部生态系统服务提升及资源合理利用与配置提供科学依据。展开更多
Dear Editor,This letter presents an improved repetitive controller(IRC) that uses a complex-coefficient filter to enhance the tracking performance of a system for periodic signals. Compared with the low-pass filter us...Dear Editor,This letter presents an improved repetitive controller(IRC) that uses a complex-coefficient filter to enhance the tracking performance of a system for periodic signals. Compared with the low-pass filter used in the conventional repetitive controller(CRC), the complex-coefficient filter causes less change in the phase and amplitude of a signal at the frequencies of the periodic signal, especially at the fundamental frequency, when the two filters have the same cutofffrequency.展开更多
Due to the existence of oxide layer on the surface of Q235 steel,it is difficult to directly achieve metallurgical bonding with tin-lead al-loy,in order to solve this problem,this paper designed and successfully prepa...Due to the existence of oxide layer on the surface of Q235 steel,it is difficult to directly achieve metallurgical bonding with tin-lead al-loy,in order to solve this problem,this paper designed and successfully prepared steel surface activation liquid with the composition of 1 L distilled water,130 g ZnCl_(2),90 g NH_(4)Cl,5 mL 6501,and adding C_(3)H_(6)O_(3)to adjust pH 3.The results show that the activated mol-ten tin-lead alloy has a low wetting angle of 7.5°on the steel surface,which was then successfully plated on the steel surface by hot-dipping.The microstructural analysis of the plating-substrate interface and the thermodynamic calculation of the reaction can be found.The main structure of the interfacial reaction layer isα-Fe/FeSn_(2)/α-Pb+β-Sn.展开更多
Two-terminal(2-T)perovskite(PVK)/CuIn(Ga)Se_(2)(CIGS)tandem solar cells(TSCs)have been considered as an ideal tandem cell because of their best bandgap matching regarding to Shockley–Queisser(S–Q)limits.However,the ...Two-terminal(2-T)perovskite(PVK)/CuIn(Ga)Se_(2)(CIGS)tandem solar cells(TSCs)have been considered as an ideal tandem cell because of their best bandgap matching regarding to Shockley–Queisser(S–Q)limits.However,the nature of the irregular rough morphology of commercial CIGS prevents people from improving tandem device performances.In this paper,D-homoserine lactone hydrochloride is proven to improve coverage of PVK materials on irregular rough CIGS surfaces and also passivate bulk defects by modulating the growth of PVK crystals.In addition,the minority carriers near the PVK/C60 interface and the incompletely passivated trap states caused interface recombination.A surface reconstruction with 2-thiopheneethylammonium iodide and N,N-dimethylformamide assisted passivates the defect sites located at the surface and grain boundaries.Meanwhile,LiF is used to create this field effect,repelling hole carriers away from the PVK and C60 interface and thus reducing recombination.As a result,a 2-T PVK/CIGS tandem yielded a power conversion efficiency of 24.6%(0.16 cm^(2)),one of the highest results for 2-T PVK/CIGS TSCs to our knowledge.This validation underscores the potential of our methodology in achieving superior performance in PVK/CIGS tandem solar cells.展开更多
A robust ecological security network(ESN)is essential for ensuring regional ecological security,improving fragile ecological conditions,and promoting sustainable development.Climate change and land use/cover change(LU...A robust ecological security network(ESN)is essential for ensuring regional ecological security,improving fragile ecological conditions,and promoting sustainable development.Climate change and land use/cover change(LUCC)influence the structure and connectivity of the ESN by impacting ecosystem services(ESs).Previous studies primarily focused on the overall effects of LUCC on ESN changes,but they largely overlooked the effects of detailed LUCC transitions.In this study,we evaluated changes in the structure and connectivity of the ESN in the Songnen Plain(SNP),Northeast China,over the past 30 yr(1990s-2020s)using circuit theory and graph theory.We further explored the effects of climate change,LUCC,and detailed LUCC transformations on ESN changes through factorial control experiments.Results revealed a 24.86%decrease in ecological sources and a 27.06%decrease in ecological corridors,accompanied by a decline in ESN connectivity from the 1990s to the 2010s.Conversely,from the 2010s to the 2020s,ecological sources increased by 14.71%and ecological corridors increased by 25.71%due to ecological projects such as returning farmland to wetlands,resulting in an overall increase in ESN connectivity.The changes in ESN structure were primarily attributed to LUCC effects,followed by climate change effects and their interactions.In contrast,the changes in connectivity were significantly affected by climate change,followed by interactive effects and LUCC.Through detailed examination of LUCC transformation effects,we further found that the changes in ESN structure were primarily attributed to wetland loss,followed by deforestation and urban expansion.Meanwhile,the changes in ESN connectivity were mainly due to the effects of wetland loss,urban expansion and deforestation.Notably,the adverse effects of wetland loss partly offset climate change benefits on ESN.Our study offers valuable insights for developing future land management policies and implementing ecological projects,aimed at maintaining a stable ESN and ensuring sustainable human development.展开更多
Guided by the clinical concept of“intervention without implantation”,Mg alloys show promise as next-generation cardiovascular stent materials due to their complete degradability and excellent biocompatibility.Althou...Guided by the clinical concept of“intervention without implantation”,Mg alloys show promise as next-generation cardiovascular stent materials due to their complete degradability and excellent biocompatibility.Although existing drug-eluting coatings can delay Mg stent degradation and inhibit restenosis,the persistent drug release-induced delayed endothelial healing and increased thrombotic risks present a critical paradox that has severely hindered clinical translation.To address this challenge,researchers are focused on developing multifunctional coating systems that exhibit simultaneous anticoagulation and hyperplasia suppression,while promoting endothelial repair.This review systematically examines the following key research frontiers:natural bioactive molecular coatings,NO release coatings,and biofunctional molecular coatings,along with their various combinations,referred to collectively as“drug-like coatings”.The fabrication strategies,functional performance,and challenges associated with drug-like coatings are discussed,and suggestions and ideas are presented to guide future prioritization of development directions.This comprehensive analysis provides both a theoretical foundation and technological roadmaps for developing next-generation degradable Mg alloy stents with superior service performance and clinical safety.展开更多
文摘近年来,气候变化和人类干扰活动导致生态系统服务退化,严重限制区域可持续性发展。科学认知生态系统服务变化特征及其驱动机制是制定区域可持续发展和提升生态安全保障政策的基础和前提。本研究以吉林西部为研究区,运用InVEST(Integrated Valuation of Ecosystem Services and Tradeoffs Tools)模型定量评估了近10年(2010-2020年)吉林西部生态系统服务(产水量、土壤保持和生境质量),分析其时空变化特征,并揭示气候变化和土地利用/覆盖变化(LUCC)及其交互作用对生态系统服务变化的相对影响。结果表明:近10年,(1)在土地管理政策的驱动下,旱地、湿地和未利用地的面积减少,而水田、林地、草地和建设用地的面积呈增长趋势,其中减少的旱地主要转化为水田或林地。(2)近10年吉林西部生态系统服务总体呈增长趋势,且存在显著空间异质性;产水量和土壤保持量分别增加24.2%、51.6%,产水量增幅主要分布于中部和西北部的湿地和水田,土壤保持量增加区域主要位于西部和东北部的湿地和草地,而生境质量总体呈现下降趋势(-4.8%)。(3)近10年,产水量增加主要受气候变化(温度升高、降水增加)的正向影响,土壤保持量增加主要受气候变化及其与LUCC(植被覆盖增加)交互作用的影响,生境质量的下降主要由耕地面积增加和城市扩张等LUCC的负向影响。本研究结果可为吉林西部生态系统服务提升及资源合理利用与配置提供科学依据。
基金supported in part by the National Natural Science Foundation of China(61873348,6230 3266,62273200)JSPS(Japan Society for the Promotion of Science) KAKENHI(22H03998,23K25252)
文摘Dear Editor,This letter presents an improved repetitive controller(IRC) that uses a complex-coefficient filter to enhance the tracking performance of a system for periodic signals. Compared with the low-pass filter used in the conventional repetitive controller(CRC), the complex-coefficient filter causes less change in the phase and amplitude of a signal at the frequencies of the periodic signal, especially at the fundamental frequency, when the two filters have the same cutofffrequency.
基金supported by National Natural Science Foundation of China(Grant No.52305353)Postdoctoral Science Foundation of China(Grant No.2023M7408938).
文摘Due to the existence of oxide layer on the surface of Q235 steel,it is difficult to directly achieve metallurgical bonding with tin-lead al-loy,in order to solve this problem,this paper designed and successfully prepared steel surface activation liquid with the composition of 1 L distilled water,130 g ZnCl_(2),90 g NH_(4)Cl,5 mL 6501,and adding C_(3)H_(6)O_(3)to adjust pH 3.The results show that the activated mol-ten tin-lead alloy has a low wetting angle of 7.5°on the steel surface,which was then successfully plated on the steel surface by hot-dipping.The microstructural analysis of the plating-substrate interface and the thermodynamic calculation of the reaction can be found.The main structure of the interfacial reaction layer isα-Fe/FeSn_(2)/α-Pb+β-Sn.
基金supported by“National Natural Science Foundation of China(U21A20171,U20A20245)”“Hubei Provincial Natural Science Foundation of China(2023AFA010)”+1 种基金“Independent Innovation Projects of the Hubei Longzhong Laboratory(2022ZZ-09)”“Social Public Welfare and Basic Research Special Project of Zhongshan(2020B2015).”。
文摘Two-terminal(2-T)perovskite(PVK)/CuIn(Ga)Se_(2)(CIGS)tandem solar cells(TSCs)have been considered as an ideal tandem cell because of their best bandgap matching regarding to Shockley–Queisser(S–Q)limits.However,the nature of the irregular rough morphology of commercial CIGS prevents people from improving tandem device performances.In this paper,D-homoserine lactone hydrochloride is proven to improve coverage of PVK materials on irregular rough CIGS surfaces and also passivate bulk defects by modulating the growth of PVK crystals.In addition,the minority carriers near the PVK/C60 interface and the incompletely passivated trap states caused interface recombination.A surface reconstruction with 2-thiopheneethylammonium iodide and N,N-dimethylformamide assisted passivates the defect sites located at the surface and grain boundaries.Meanwhile,LiF is used to create this field effect,repelling hole carriers away from the PVK and C60 interface and thus reducing recombination.As a result,a 2-T PVK/CIGS tandem yielded a power conversion efficiency of 24.6%(0.16 cm^(2)),one of the highest results for 2-T PVK/CIGS TSCs to our knowledge.This validation underscores the potential of our methodology in achieving superior performance in PVK/CIGS tandem solar cells.
基金Under the auspices of National Key Research and Development Program of China(No.2022YFF1300904)the National Natural Science Foundation of China(No.42271119,42371075,42471127)+1 种基金Youth Innovation Promotion Association,Chinese Academy of Sciences(No.2023238)Jilin Province Science and Technology Development Plan Project(No.20230203001SF)。
文摘A robust ecological security network(ESN)is essential for ensuring regional ecological security,improving fragile ecological conditions,and promoting sustainable development.Climate change and land use/cover change(LUCC)influence the structure and connectivity of the ESN by impacting ecosystem services(ESs).Previous studies primarily focused on the overall effects of LUCC on ESN changes,but they largely overlooked the effects of detailed LUCC transitions.In this study,we evaluated changes in the structure and connectivity of the ESN in the Songnen Plain(SNP),Northeast China,over the past 30 yr(1990s-2020s)using circuit theory and graph theory.We further explored the effects of climate change,LUCC,and detailed LUCC transformations on ESN changes through factorial control experiments.Results revealed a 24.86%decrease in ecological sources and a 27.06%decrease in ecological corridors,accompanied by a decline in ESN connectivity from the 1990s to the 2010s.Conversely,from the 2010s to the 2020s,ecological sources increased by 14.71%and ecological corridors increased by 25.71%due to ecological projects such as returning farmland to wetlands,resulting in an overall increase in ESN connectivity.The changes in ESN structure were primarily attributed to LUCC effects,followed by climate change effects and their interactions.In contrast,the changes in connectivity were significantly affected by climate change,followed by interactive effects and LUCC.Through detailed examination of LUCC transformation effects,we further found that the changes in ESN structure were primarily attributed to wetland loss,followed by deforestation and urban expansion.Meanwhile,the changes in ESN connectivity were mainly due to the effects of wetland loss,urban expansion and deforestation.Notably,the adverse effects of wetland loss partly offset climate change benefits on ESN.Our study offers valuable insights for developing future land management policies and implementing ecological projects,aimed at maintaining a stable ESN and ensuring sustainable human development.
基金the High-level Talent Research Start-up Project Funding of Henan Academy of Sciences(Project NO.241817243)the Fundamental Research Fund of Henan Academy of Sciences(Project NO.20250617002)+1 种基金the Scientific and Technological Research Project of Henan Province(Project NO.252102230110)the National Key Research and Development Program of China(NO.2021YFC2400703).
文摘Guided by the clinical concept of“intervention without implantation”,Mg alloys show promise as next-generation cardiovascular stent materials due to their complete degradability and excellent biocompatibility.Although existing drug-eluting coatings can delay Mg stent degradation and inhibit restenosis,the persistent drug release-induced delayed endothelial healing and increased thrombotic risks present a critical paradox that has severely hindered clinical translation.To address this challenge,researchers are focused on developing multifunctional coating systems that exhibit simultaneous anticoagulation and hyperplasia suppression,while promoting endothelial repair.This review systematically examines the following key research frontiers:natural bioactive molecular coatings,NO release coatings,and biofunctional molecular coatings,along with their various combinations,referred to collectively as“drug-like coatings”.The fabrication strategies,functional performance,and challenges associated with drug-like coatings are discussed,and suggestions and ideas are presented to guide future prioritization of development directions.This comprehensive analysis provides both a theoretical foundation and technological roadmaps for developing next-generation degradable Mg alloy stents with superior service performance and clinical safety.
