数字逻辑电路的描述及模块化综合方法

随着电子设计自动化技术的进步 ,大多数现代数字电路或系统的设计工程都离不开计算机辅助设计(CAD)工具的帮助 ,尤其是出现了高级语言描述、系统仿真和综合技术为特征的第三代EDA技术。因此掌握好数字逻辑电路或系统的描述 (建模 )方法和综合步骤是至关重要的。介绍了高级描述语言VHDL的行为描述和结构描述的若干种模型 ,并通过一个设计实例阐述了数字逻辑电路的设计循环从定义到实现的综合过程     

Investigating Overall Technical Efficiency in China Commercial Banks： a DEA Approach

Based on the non-Archimedian infinite model C^2R of the Data Envelopment Analysis, combined with characteristics of Chinese mainland banks＇ inputs and outputs, the paper sets up an index system of inputs and outputs as well as an overall technical efficiency evaluation model for Chinese banks, which considers not only the profit ability, but also the control capacity of banks risk. The overall technical efficiency values of Chinese banks are given respectively based on the samples of state owned banks and 14 integrated samples both state owned banks and shareholding banks. The input redundancy of labor, net value fixed assets, operating expenses, owner＇s equity, branch number and output deficiency of operating income, total increase in deposits, total increase in loans, ROE, decrease in bad debts ratio, are also calculated. The pertinence policy suggestions of efficiency improvement of banks are put forward. The results show that the efficiencies of new shareholding banks are far higher than non-shareholding bank and the all four state owned banks are commonly lower in overall technical efficiency. The overall technical efficiency of Agriculture Bank of China is the lowest one in all banks, and Bank of Communications is the efficiency lowest in all shareholding banks. The contributions and characteristics of the paper are： 1） the bad debit ratio is used to reflect the quality of the outputs, which is an improvement to the current literature of neglecting the difference in loans quality. 2） The inefficiency reasons of banks are list out by quantity analysis, and the pertinent macro strategies and concrete measures on improving banks efficiency are given, which is another improvement to current research that tend to give the efficiency value, but not ignore giving improving strategy from quantities analysis. 3） Banks overall technical efficiency values under several portfolios of inputs and outputs are given respectively, which not only overcomes the restraints that the sample size is at least the 2 times of the number of inputs and outputs indexes, but also measures banks overall technical efficiency from several directions. 4） It makes the efficiency values estimation more comparable by extracting four state owned banks for another efficiency evaluation. Combining both state owned banks and shareholding banks as a whole group of efficiency evaluation shows the real overall technical efficiency distance between two different kinds of bank and provide realistic basis for the bank reform of China.     

过程系统寻优新方法——非线性映射主轴分析法

对于实际过程系统的寻优,大都是多维的非线性优化问题,寻求一种全局稳定最优数值解的方法,一直是人们关注的课题．本文应用人工神经网络的拓扑映射技术,提出非线性映射主轴分析法．这种新方法将一个多维空间的非线性问题降维映射到二维平面,籍目标函数等值分布曲线的分析,决策出最优点或最优区域,通过逆映射运算可将其还原到多维空间用原始变量表示．从本文的例证可见,这种方法直观、简便、有效、得出的最优解准确、可靠     

建设用地地质灾害危险性评估关键技术问题的探讨

就建设用地地质灾害危险性评估工作中关于现状评估与预测评估的关系、地质灾害体规模划分、地质灾害易发性评价、地质灾害体的稳定性评价和地质灾害危险区划分等关键技术问题开展讨论.     

高温情况下异核双原子分子转动热容量的讨论

分析了气体异核双原子分子的转动热容量 ,讨论了在高温情况下双原子分子的离心畸变和核的振动状态对转动热容量的影响     

铁路发展与近代人口流动

铁路在中国兴建之后，作为一种新式交通工具促进了人口流动。铁路是近代向南北移民的主要交通工具；因铁路之兴建，大批外国侨民移入中国；在救助灾民、难民方面，铁路发挥了重要作用；其自身修筑也吸纳了大量人口，我们要充分肯定铁路在促进人口流动过程中的重要作用。     

Ring-opening and Elimination Cooligomerization of Cyclic Carbonates and ε-Caprolactone

1Introduction Cyclic carbonates e.g. ethylene- and propylene carbonate undergo ring-opening polymerization (ROP) at elevated temperatures (＞ 100 ℃ ) in the presence of initiators such as Lewis acids, bases, or transesterification catalysts to yield poly(ether carbonates) as outlined below. See Fig. 1.     

The endothelial-cell-derived secreted factor Egfl7 regulates vascular tube formation

Vascular development is a complex but orderly process that is tightly regulated. A number of secreted factors produced by surrounding cells regulate endothelial cell (EC) differentiation, proliferation, migration and coalescence into cord-like structures. Vascular cords then undergo tubulogenesis to form vessels with a central lumen. But little is known about how tubulogenesis is regulated in vivo. Here we report the identification and characterization of a new EC-derived secreted factor, EGF-like domain 7 (Egfl7). Egfl7 is expressed at high levels in the vasculature associated with tissue proliferation, and is downregulated in most of the mature vessels in normal adult tissues. Loss of Egfl7 function in zebrafish embryos specifically blocks vascular tubulogenesis. We uncover a dynamic process during which gradual separation and proper spatial arrangement of the angioblasts allow subsequent assembly of vascular tubes. This process fails to take place in Egfl7 knockdown embryos, leading to the failure of vascular tube formation. Our study defines a regulator that controls a specific and important step in vasculogenesis.