Perovskite oxides have been widely applied as an effective catalyst in heterogeneous catalysis.However,the rational design of active catalysts has been restricted by the lack of understanding of the electronic structu...Perovskite oxides have been widely applied as an effective catalyst in heterogeneous catalysis.However,the rational design of active catalysts has been restricted by the lack of understanding of the electronic structure.The correlations between surface properties and bulk electronic structure have been ignored.Herein,a simple handler of LaFeO_(3)with diluted HNO3 was employed to tune the electronic structure and catalytic properties.Experimental analysis and theoretical calculations elucidate that acid etching could raise the Fe valence and enhance Fe-O covalency in the octahedral structure,thereby lessening charge transfer energy.Enhanced Fe-O covalency could lower oxygen vacancy formation energy and enhance oxygen mobility.In-situ DRIFTS results indicated the inherent adsorption capability of Toluene and CO molecules has been greatly improved owing to higher Fe-O covalency.As compared,the catalysts after acid etching exhibited higher catalytic activity,and the T_(90)had a great reduction of 45 and 58℃ for toluene and CO oxidation,respectively.A deeper understanding of electronic structure in perovskite oxides may inspire the design of high-performance catalysts.展开更多
Elevation change monitoring of the Antarctic ice sheet has been a key issue in global change research.Satellite altimetry has been proven to be effective in detecting ice sheet variations. With the development of ICES...Elevation change monitoring of the Antarctic ice sheet has been a key issue in global change research.Satellite altimetry has been proven to be effective in detecting ice sheet variations. With the development of ICESat-2, many elevation observations can be used to derive elevation changes. However, the large amount of multitemporal data may include anomalous data points, increasing the uncertainty of the results. In this work, we improved the traditional repeat track method by introducing the Institute of Geodesy and Geophysics Ⅲ(IGGⅢ) method to obtain high-accuracy estimates of elevation change. The improved method was applied to analyze elevation changes along the transect from Zhongshan Station to Dome A in East Antarctica via ICESat-2 satellite altimetry data. The results show that the improved and traditional methods yield consistent numerical and spatial elevation change distributions. The elevation change calculated via the traditional method is 0.033 ± 0.131 m/yr, whereas the elevation change estimated via the IGGⅢ robust estimation method is 0.033 ± 0.109 m/yr from March 2019 to December 2021.In terms of spatial distribution, elevation changes in inland areas remain close to equilibrium, whereas regions with steeper ice sheet margins exhibit positive accumulation trends in elevation changes. The improved method reduces the standard error of the adjustment function from 0.975 to 0.691 m/yr. The improvement is particularly remarkable in the area between 72°S and 77°S. The results demonstrate that the IGGⅢ method effectively reduces errors caused by the inclusion of anomalous data and maintains the high data utilization rate of repeat-orbit methods.展开更多
Due to the high-order B-spline basis functions utilized in isogeometric analysis(IGA)and the repeatedly updating global stiffness matrix of topology optimization,Isogeometric topology optimization(ITO)intrinsically su...Due to the high-order B-spline basis functions utilized in isogeometric analysis(IGA)and the repeatedly updating global stiffness matrix of topology optimization,Isogeometric topology optimization(ITO)intrinsically suffers from the computationally demanding process.In this work,we address the efficiency problem existing in the assembling stiffness matrix and sensitivity analysis using B˙ezier element stiffness mapping.The Element-wise and Interaction-wise parallel computing frameworks for updating the global stiffness matrix are proposed for ITO with B˙ezier element stiffness mapping,which differs from these ones with the traditional Gaussian integrals utilized.Since the explicit stiffness computation formula derived from B˙ezier element stiffness mapping possesses a typical parallel structure,the presented GPU-enabled ITO method can greatly accelerate the computation speed while maintaining its high memory efficiency unaltered.Numerical examples demonstrate threefold speedup:1)the assembling stiffness matrix is accelerated by 10×maximumly with the proposed GPU strategy;2)the solution efficiency of a sparse linear system is enhanced by up to 30×with Eigen replaced by AMGCL;3)the efficiency of sensitivity analysis is promoted by 100×with GPU applied.Therefore,the proposed method is a promising way to enhance the numerical efficiency of ITO for both single-patch and multiple-patch design problems.展开更多
With the accelerating process of transformation and upgrading of China’s manufacturing industry,employers’requirements for the professional qualities and skills of technical workers are increasing day by day.As the ...With the accelerating process of transformation and upgrading of China’s manufacturing industry,employers’requirements for the professional qualities and skills of technical workers are increasing day by day.As the core value to promote high-quality development,the craftsman spirit has become an important part of vocational education.Taking the Mechanical Foundation course of the mechanical major in a technician college as an example,this study tracked and analyzed the teaching effect of integrating the craftsman spirit into the course for one academic year.By comparing the performance of students before and after integrating the craftsman spirit into daily teaching,it explored its influence on students’professional skills,innovation ability,and professional qualities.The study collected data through questionnaires,classroom observations,etc.,providing a practical basis for the promotion of the craftsman spirit in vocational education and curriculum reform in the future.展开更多
基金the National Natural Science Foundation of China(Nos.22376178,22322606,22276105)the National Key Research and Development Program of China(No.2022YFC3704300)the Beijing Natural Science Foundation(No.8222054).
文摘Perovskite oxides have been widely applied as an effective catalyst in heterogeneous catalysis.However,the rational design of active catalysts has been restricted by the lack of understanding of the electronic structure.The correlations between surface properties and bulk electronic structure have been ignored.Herein,a simple handler of LaFeO_(3)with diluted HNO3 was employed to tune the electronic structure and catalytic properties.Experimental analysis and theoretical calculations elucidate that acid etching could raise the Fe valence and enhance Fe-O covalency in the octahedral structure,thereby lessening charge transfer energy.Enhanced Fe-O covalency could lower oxygen vacancy formation energy and enhance oxygen mobility.In-situ DRIFTS results indicated the inherent adsorption capability of Toluene and CO molecules has been greatly improved owing to higher Fe-O covalency.As compared,the catalysts after acid etching exhibited higher catalytic activity,and the T_(90)had a great reduction of 45 and 58℃ for toluene and CO oxidation,respectively.A deeper understanding of electronic structure in perovskite oxides may inspire the design of high-performance catalysts.
基金supported by the National Key Research and Development Program of China under grant number 2023YFC2809103the Fundamental Research Funds for the Central Universities under grant numbers 2042022kf1204, 2042022kf1069, 2042023gf0012, 2042022dx0001+1 种基金the Hubei Provincial Natural Science Foundation of China under grant number 2022CFB081the State Key Laboratory of Geodesy and Earth's Dynamics, Innovation Academy for Precision Measurement Science and Technology under grant number SKLGED2023-2-6
文摘Elevation change monitoring of the Antarctic ice sheet has been a key issue in global change research.Satellite altimetry has been proven to be effective in detecting ice sheet variations. With the development of ICESat-2, many elevation observations can be used to derive elevation changes. However, the large amount of multitemporal data may include anomalous data points, increasing the uncertainty of the results. In this work, we improved the traditional repeat track method by introducing the Institute of Geodesy and Geophysics Ⅲ(IGGⅢ) method to obtain high-accuracy estimates of elevation change. The improved method was applied to analyze elevation changes along the transect from Zhongshan Station to Dome A in East Antarctica via ICESat-2 satellite altimetry data. The results show that the improved and traditional methods yield consistent numerical and spatial elevation change distributions. The elevation change calculated via the traditional method is 0.033 ± 0.131 m/yr, whereas the elevation change estimated via the IGGⅢ robust estimation method is 0.033 ± 0.109 m/yr from March 2019 to December 2021.In terms of spatial distribution, elevation changes in inland areas remain close to equilibrium, whereas regions with steeper ice sheet margins exhibit positive accumulation trends in elevation changes. The improved method reduces the standard error of the adjustment function from 0.975 to 0.691 m/yr. The improvement is particularly remarkable in the area between 72°S and 77°S. The results demonstrate that the IGGⅢ method effectively reduces errors caused by the inclusion of anomalous data and maintains the high data utilization rate of repeat-orbit methods.
基金supported by the National Key R&D Program of China(2023YFB2504601)National Natural Science Foundation of China(52205267).
文摘Due to the high-order B-spline basis functions utilized in isogeometric analysis(IGA)and the repeatedly updating global stiffness matrix of topology optimization,Isogeometric topology optimization(ITO)intrinsically suffers from the computationally demanding process.In this work,we address the efficiency problem existing in the assembling stiffness matrix and sensitivity analysis using B˙ezier element stiffness mapping.The Element-wise and Interaction-wise parallel computing frameworks for updating the global stiffness matrix are proposed for ITO with B˙ezier element stiffness mapping,which differs from these ones with the traditional Gaussian integrals utilized.Since the explicit stiffness computation formula derived from B˙ezier element stiffness mapping possesses a typical parallel structure,the presented GPU-enabled ITO method can greatly accelerate the computation speed while maintaining its high memory efficiency unaltered.Numerical examples demonstrate threefold speedup:1)the assembling stiffness matrix is accelerated by 10×maximumly with the proposed GPU strategy;2)the solution efficiency of a sparse linear system is enhanced by up to 30×with Eigen replaced by AMGCL;3)the efficiency of sensitivity analysis is promoted by 100×with GPU applied.Therefore,the proposed method is a promising way to enhance the numerical efficiency of ITO for both single-patch and multiple-patch design problems.
基金This paper is the research result of the project“Research on the Integration and Implementation Strategy of the‘Craftsman Spirit of a Great Nation’in the Mechanical Professional Courses of Vocational Colleges:Taking a Technician College as an Example”of the Social Science Federation of Pingxiang City,Jiangxi Province(2024PXSK81).
文摘With the accelerating process of transformation and upgrading of China’s manufacturing industry,employers’requirements for the professional qualities and skills of technical workers are increasing day by day.As the core value to promote high-quality development,the craftsman spirit has become an important part of vocational education.Taking the Mechanical Foundation course of the mechanical major in a technician college as an example,this study tracked and analyzed the teaching effect of integrating the craftsman spirit into the course for one academic year.By comparing the performance of students before and after integrating the craftsman spirit into daily teaching,it explored its influence on students’professional skills,innovation ability,and professional qualities.The study collected data through questionnaires,classroom observations,etc.,providing a practical basis for the promotion of the craftsman spirit in vocational education and curriculum reform in the future.
