现行条件下高职教育实行学分制管理的主要框架设计

本文从实行学分制应着重注意的几个问题出发，根据目前条件下高职教育的特点及现状，提出了学分制的主要框架设计及应处理好的几个关系。     

基于生命周期和交叠世代分析的养老风险管理文献综述及其启示

随着长寿风险的加剧以及人口死亡率的降低，养老风险管理的研究逐渐受到政府和学术界的广泛关注。本文系统梳理了养老风险相关驱动因素(死亡率和长寿风险)的研究，并介绍了生命周期框架与交叠世代模型(OLG)的建模过程，还对生命周期框架和OLG模型的应用研究进行了文献综述。从文献回顾来看，当前研究存在一些不足，未来的研究应基于我国人口生存特征去研究死亡率；同时，需要从生命周期框架和OLG模型研究研究应对养老风险的稳健的投资-消费决策，并在考虑对上一代老人赡养的情形下研究寿险决策。此外，随着养老风险逐步加剧，建议政府采取改进我国的多支柱养老保险体系、进一步放开生育、延迟退休及发展养老服务业等方式应对养老风险，保证我国养老金体系的可持续发展。     

APPLICATION OF VARIABLE-FIDELITY MODELS TO AERODYNAMIC OPTIMIZATION

For aerodynamic shape optimization, the approximation management framework (AMF) method is used to organize and manage the variable-fidelity models. The method can take full advantage of the low-fidelity, cheaper models to concentrate the main workload on the low-fidelity models in optimization iterative procedure. Furthermore, it can take high-fidelity, more expensive models to monitor the procedure to make the method globally convergent to a solution of high-fidelity problem. Finally, zero order variable-fidelity aerodynamic optimization management framework and search algorithm are demonstrated on an airfoil optimization of UAV with a flying wing. Compared to the original shape, the aerodynamic performance of the optimal shape is improved. The results show the method has good feasibility and applicability.     

共价有机框架材料在吸附领域的研究进展

共价有机框架材料(Covalent Organic Frameworks,COFs)是由有机结构单元通过共价键连接的具有期性结构的多孔化合物。共价有机框架材料具有永久的孔隙、高的比表面积、可调的孔径、易于功能化和高的水热稳定性等优点,广泛应用于许多领域。本文总结了COFs目前主要的合成方法,介绍了COFs在吸附领域的应用和发展。最后,文章指出未来的研究重点是发展更多有机反应和键连方式,合成具有高度稳定性和结晶度、成本低廉的功能性材料。     

机载多框架光电吊舱两级隔振设计

在分析了目前常用的机载光电设备隔振系统的基础上,针对两轴四框架的结构特点,提出了一种基于多框架的两级隔振方案,克服了目前隔振系统体积、重量大,加工装配要求高的缺点。基于隔振模型的理论计算表明,根据系统给定的质量比和频率比,优化选择内外框架的刚度比,即选择合适的内外框隔振器可达到理想的隔振效果。通过某型光电吊舱的扫频实验...     

Comment on phase conventions in helicity formalism

Using the sequential decay process m e⁺e^- → J/ψ → ΛΛ, Λ → pπ^-, Λ → pπ⁺ as an example, the procedure for deducing the full angular distribution is illustrated by adopting both the Jacob-Wick and Jackson conventions in the helicity formalism. To make sure that the final physical result is free of phase conventions, we point out that the coefficients that relate the angular momentum states in different coordinate systems of reference frames have to be taken into account properly in the procedure. The fact that those coefficients are constants suggests that the Jackson convention is favorable in dealing with the processes with sequential decays.     

Quantitative conditions for the formation of p-wave neutron halos

With the experimental binding energies and configurations, the root-mean-square radii of p-wave valence neutron distributions for nuclei up to the second p-shell have been calculated in the framework of the single-particle potential model. By analyzing the relations between the radii and the binding energies, the scaling laws of p-wave valence neutron distributions are obtained. The quantitative conditions for the formation of p-wave neutron halos are deduced from these scaling laws. Based on the investigation on the probability of finding the valence nucleon outside the range of the interaction potential, a 2p_3/2 halo state in ⁴⁷S is anticipated for the first time. These obtained results might provide reference for searching for p-wave neutron halos in nuclei up to the second p-shell.     

L~2(R~n)上的半正交多小波框架

本文研究L2(Rn)上伸缩矩阵A满足|detA|1的半正交多小波框架.本文得到半正交和严格半正交框架的一系列性质及刻画.本文证明半正交Parseval多小波框架与广义多分辨分析(GMRA)Parseval多小波框架是等价的.特别地,本文利用最小频率支撑(MSF)多小波框架和小波集,构造若干半正交多小波框架的例子.