(?)-Aryl-(?)-cyanosulfones are prepared under mild conditions with good yields by using palladium-catalyzed coupling reaction between aryl halides and (?)-cyanosulfones in the presence of phase transfer catalyst.
Comparative experiments show that ultrasonic irradiation reduces the reaction times and improves the yields in the di-alkylation and cyclo-di-alkylation of ethyl cyanoacetate under solid-liquid phase transfer conditions.
A convenient synthetic approach leading to protected inositol was described based on regioselective O-alkylation using alkyl halide under solid-liquid PTC condition
China’s anti-poverty strategy in the post-2020 era will focus on reducing chronic poverty and alleviating relative poverty.As a common international approach for long-term multidimensional poverty reduction,condition...China’s anti-poverty strategy in the post-2020 era will focus on reducing chronic poverty and alleviating relative poverty.As a common international approach for long-term multidimensional poverty reduction,conditional cash transfer(CCT)payments reduce current poverty,prevent future poverty,and improve income distribution by providing poor households with cash allowances and promoting children’s human capital accumulation.For such reasons,CCT serves as an anti-poverty policy instrument worth referencing for China.This paper systematically reviewed the theoretical basis and development journey of CCT,the short-term and long-term implementation effects,as well as the decision-making basis,design and potential limitations.In this paper,we have further analyzed the poverty-reducing effects and problems of China’s rural public transfer payment policies in the current stage and discussed the achievements and inadequacies of China’s ongoing CCT pilot programs.Results indicate that the further development of CCT in China calls for a combination top-down and bottom-up policy-making approaches in project design and implementation,as well as an evolving poverty governance system complementary with other relevant policies.展开更多
Numerical simulation based on computational fluid dynamics (CFD) is a useful approach for quantitatively investigating the underlying thermal-mechanical conditions during FSW, such as temperature field and material ...Numerical simulation based on computational fluid dynamics (CFD) is a useful approach for quantitatively investigating the underlying thermal-mechanical conditions during FSW, such as temperature field and material deformation field. One of the critical issues in CFD simulation of FSW is the use of the frictional boundary condition, which represents the friction between the welding tool and the workpiece in the numerical models. In this study, three-dimensional numerical simulation is conducted to analyze the heat transfer and plastic deformation behaviors during the FSW of AA2024. For comparison purposes, both the boundary velocity (BV) models and the boundary shear stress (BSS) models are employed in order to assess their performances in predicting the temperature and material deformation in FSW. It is interesting to note that different boundary conditions yield similar predictions on temperature, but quite different predictions on material deformation. The numerical predictions are compared with the experimental results. The predicted deformation zone geometry by the BSS model is consistent with the experimental results while there is large difference between the predictions by the BV models and the experimental measurements. The fact that the BSS model yields more reasonable predictions on the deformation zone geometry is attributed to its capacity to automatically adjust the contact state at the tool/workpiece interface. Based on the favorable predictions on both the temperature field and the material deformation field, the BSS model is suggested to have a better performance in numerical simulation of FSW than the BV model.展开更多
基金Supported by Natural Science Foundation of Zhejiang Province
文摘(?)-Aryl-(?)-cyanosulfones are prepared under mild conditions with good yields by using palladium-catalyzed coupling reaction between aryl halides and (?)-cyanosulfones in the presence of phase transfer catalyst.
文摘Comparative experiments show that ultrasonic irradiation reduces the reaction times and improves the yields in the di-alkylation and cyclo-di-alkylation of ethyl cyanoacetate under solid-liquid phase transfer conditions.
文摘A convenient synthetic approach leading to protected inositol was described based on regioselective O-alkylation using alkyl halide under solid-liquid PTC condition
基金supported by the MOE(Ministry of Education of China)Project of Humanities and Social Sciences“Study on the Effects of Public Transfer Payments on the Human Capital Accumulation of Rural Children”(Grant No.20YJC790187)the National Social Science Fund of China(NSSFC)project“Study on the Effects of New-type Rural Pension Insurance on Rural Left-behind Elderly Persons”(Grant No.17BRK018).
文摘China’s anti-poverty strategy in the post-2020 era will focus on reducing chronic poverty and alleviating relative poverty.As a common international approach for long-term multidimensional poverty reduction,conditional cash transfer(CCT)payments reduce current poverty,prevent future poverty,and improve income distribution by providing poor households with cash allowances and promoting children’s human capital accumulation.For such reasons,CCT serves as an anti-poverty policy instrument worth referencing for China.This paper systematically reviewed the theoretical basis and development journey of CCT,the short-term and long-term implementation effects,as well as the decision-making basis,design and potential limitations.In this paper,we have further analyzed the poverty-reducing effects and problems of China’s rural public transfer payment policies in the current stage and discussed the achievements and inadequacies of China’s ongoing CCT pilot programs.Results indicate that the further development of CCT in China calls for a combination top-down and bottom-up policy-making approaches in project design and implementation,as well as an evolving poverty governance system complementary with other relevant policies.
基金supported by the National Natural Science Foundation of China(Grant No.51375259 and Grant No.51705280)the Ministry of Science and Technology of China(Grant No.2012ZX04012-011)+1 种基金Special Program for Applied Research on Super Computation of the NSFC-Guangdong Joint Fund(the second phase,Grant No.U1501501)the Tsinghua National Laboratory for Information Science and Technology
文摘Numerical simulation based on computational fluid dynamics (CFD) is a useful approach for quantitatively investigating the underlying thermal-mechanical conditions during FSW, such as temperature field and material deformation field. One of the critical issues in CFD simulation of FSW is the use of the frictional boundary condition, which represents the friction between the welding tool and the workpiece in the numerical models. In this study, three-dimensional numerical simulation is conducted to analyze the heat transfer and plastic deformation behaviors during the FSW of AA2024. For comparison purposes, both the boundary velocity (BV) models and the boundary shear stress (BSS) models are employed in order to assess their performances in predicting the temperature and material deformation in FSW. It is interesting to note that different boundary conditions yield similar predictions on temperature, but quite different predictions on material deformation. The numerical predictions are compared with the experimental results. The predicted deformation zone geometry by the BSS model is consistent with the experimental results while there is large difference between the predictions by the BV models and the experimental measurements. The fact that the BSS model yields more reasonable predictions on the deformation zone geometry is attributed to its capacity to automatically adjust the contact state at the tool/workpiece interface. Based on the favorable predictions on both the temperature field and the material deformation field, the BSS model is suggested to have a better performance in numerical simulation of FSW than the BV model.