税收国际化趋势与我国涉外税制改革

在科技飞速发展、知识成为推动经济进步主要动力的今天，世界经济越来越呈现出一种一体化、国际化的趋势，这种趋势不仅增强了各国经济之间的依赖性，而且对各国的税收制度、国家间的税收协调提出了挑战，我国在经济融入世界大潮的同时也同样面临这个问题。 我国于1991年4月通过并颁布的《中华人民共和国外商投资企业和外国企业所得税法》标志着我国涉外税收的初步建立与完善。这种管理体制对于我国涉外经济的发展起到了较大的促进作用。我国经济在改革开放后的二十多年里得到了迅速的发展，经济多元化已逐步成为我国经济的一个特征。但随着我国经济参与世界经济发展程度的加深，我国现行涉外税制的局限性越来越明显，已经变得不适应这种变...With the rapid development of science and technology, knowledge has become the main power of economic progress. And the World Economy presents an integration tendency, which not only increases the dependence on each other country’s economy, but also brings up a new challenge on the taxation system and coordination of all the countries. Chinese economy is also facing such a problem when it mixes wi...学位：经济学硕士院系专业：经济学院财政金融系_财政学(含税收学)学号：19981201

冬凌草甲素作用PI3K/AKT通路诱导HeLa细胞凋亡

【目的】研究冬凌草甲素诱导HeLa细胞凋亡的作用及其机制。【方法】MTT法测定冬凌草甲素对HeLa细胞的生长抑制实验,Hoechst 33342荧光染色等观察细胞核形态学变化;LDH法研究细胞死亡的途径。流式细胞仪检测细胞的凋亡,免疫印迹实验检测相关蛋白的表达。【结果】25μmol/L以上的冬凌草甲素对宫颈癌HeLa细胞具有明显的生长抑制作用,并能诱导细胞发生凋亡,随着药物浓度的增加和作用时间的延长,细胞的生长抑制率及细胞凋亡率均明显升高,冬凌草甲素抑制细胞生长及诱导细胞发生凋亡的过程中,细胞端粒酶Akt、FKHRL、GSK3表达水平及活性显著降低。【结论】冬凌草甲素能够通过诱导人子宫颈癌HeLa细胞发生凋亡而发挥抑制HeLa细胞生长作用,抑制Akt和GSK3的活性是冬凌草甲素体外诱导人子宫颈癌HeLa细胞发生凋亡的重要作用机制之一

Beauty, Symmetry, and Magnetocaloric Effect-Four-Shell Keplerates with 104 Lanthanide Atoms

通讯作者地址: Kong, XJThe hydrolysis of Ln(ClO4)(3) in the presence of acetate leads to the assembly of the three largest known lanthanide-exclusive cluster complexes, [Nd-104(ClO4)(6)(CH3COO)(60)(mu(3)-OH)(168)(mu(4)-O)(30)(H2O)(112)].(ClO4)(18).(CH3CH2OH)(8).xH(2)O (1, x approximate to 158) and [Ln(104)(ClO4)(6)(CH3COO)(56)(mu(3)-OH)(168)(mu(4)-O)(30)(H2O)(112)].(ClO4)(22).(CH3CH2OH)(2).xH(2)O (2, Ln = Nd; 3, Ln = Gd; x approximate to 140). The structure of the common 104-lanthanide core, abbreviated as Ln(8)@Ln(48)@Ln(24)@Ln(24), features a four-shell arrangement of the metal atoms contained in an innermost cube (a Platonic solid) and, moving outward, three Archimedean solids: a truncated cuboctahedron, a truncated octahedron, and a rhombicuboctahedron. The magnetic entropy change of Delta Sm = 46.9 J kg(-1) K-1 at 2 K for Delta H = 7 T in the case of the Gd-104 cluster is the largest among previously known lanthanide-exclusive cluster compounds.973 Project from the Ministry of Science and Technology of China 2012CB821704 2014CB845601 National Natural Science Foundation of China 21422106 21371144 21431005 21390391 Foundation for the Author of National Excellent Doctoral Dissertation of China 201219 U.S. NSF APVV-0132-11 3001690 Czech Research Infrastructures LM201102

Study on Long-term Average Sediment Transport Modulus of China

利用全国 2 2 2个水文站实测的多年平均输沙量资料 ,在GIS软件ARC INFO及数据库软件VISUALFOX PRO的支持下 ,得到了全国多年平均输沙模数等值线图 ,分析了全国泥沙输移及淤积的宏观分布规律 ,并分类统计了不同输沙强度的总面