核子中海夸克、胶子的极化分布函数的解析计算

利用A-P方程,通过Mellin变换技巧和对演化函数的Mellin变换结果作展开近似,求得了核子中海夸克、胶子的极化分布函数随Q~2变化的解析表达式,并利用所得结果讨论了核子中海夸克、胶子的极化与Q~2的关系。     

比较优势、自主创新、经济增长和收入分配——何为中国未来经济发展之道路?

本文通过分析比较优势和自主创新两种经济增长方式的区别和联系,并引入收入分配的概念,借助经济福利分析方法来比较两种增长模式的利弊。借鉴国际经验,结合中国的现实,阐明了一国在以上两种不同的增长方式间进行选择的条件和时机。由于中国的资源禀赋、人力资本结构、技术水平和制度因素的制约,因此,选择基于比较优势的增长模式对于中国加快经济发展、增加经济福利、公平收入分配是有好处的。     

Expanding the focus of cost–benefit analysis for food safety: a multi-factorial risk prioritization approach

A pressing need in the area of food safety is a tool for making overall, macro-judgments about which risks should be given priority for management. Governments often seek to base this prioritization on public health impacts only to find that other considerations also influence the prioritization process. A multi-factorial approach formally recognizes that public health, market-level impacts, consumer risk preferences and acceptance, and the social sensitivity of particular risks all play a role in prioritization. It also provides decision-makers with a variety of information outputs that allow risk prioritization to be considered along different dimensions. Macro-level prioritization of risks based on multiple factors is an important expanded use of cost–benefit analysis to manage risk.     

A Bayesian method of sample size determination with practical applications

Summary.  The problem motivating the paper is the determination of sample size in clinical trials under normal likelihoods and at the substantive testing stage of a financial audit where normality is not an appropriate assumption. A combination of analytical and simulation-based techniques within the Bayesian framework is proposed. The framework accommodates two different prior distributions: one is the general purpose fitting prior distribution that is used in Bayesian analysis and the other is the expert subjective prior distribution, the sampling prior which is believed to generate the parameter values which in turn generate the data. We obtain many theoretical results and one key result is that typical non-informative prior distributions lead to very small sample sizes. In contrast, a very informative prior distribution may either lead to a very small or a very large sample size depending on the location of the centre of the prior distribution and the hypothesized value of the parameter. The methods that are developed are quite general and can be applied to other sample size determination problems. Some numerical illustrations which bring out many other aspects of the optimum sample size are given.     

日本对华直接投资的行业布局及对策研究

入世后,我国利用外资的战略思想更加凸显出对“结构、质量、效益”的偏好,战略目标确定为以优化产业结构为重点,增强利用外资的总体经济效益。日本是我国引进外资的主要来源国之一,日本企业对华直接投资的行业比较多。文章分析了日资企业产业分布的现状、原因,并提出了优化日资企业产业分布的对策。     

电场中气泡在换热表面上的变形及对沸腾换热影响

从电场分布的角度，研究了换热表面上气泡在电场力作用下的变形规律和气泡变形影响EHD(electrohydrodynaInics)强化沸腾换热的机理．电场分布决定了气泡在电场力作用下的变形方式，如果换热表面的电场强度高于周围液体或电极的电场强度，则气泡受拉伸作用：反之，气泡受压制作用．热边界层的存在会减小电场力对气泡的拉伸作用，增强电场力对气泡的压制作用，但不会改变气泡的变形方式，气泡在换热表面上无论是被拉伸还是被压制，都能使沸腾换热得到强化，但两者的强化换热机理不同。     

按资本贡献分配的经济学分析

按资本贡献分配是一种重要的分配方式。充分发挥按资本贡献分配的作用能够提高资本要素的配置效率,这对于资本要素相对稀缺的经济体意义重大。对按资本贡献分配的微观经济学分析与宏观经济学分析从理论上证明按资本贡献分配具有极其重要的意义。     

改进非平稳信号的分析方法

研究了WVD和短时傅里叶变换两种时频分析方法的优势和局限性,从两种方法的定义出发,分析了两者间存在的联系,通过构造窗函数,提出一种改进的非平稳信号分析方法,并进行了相应的计算机仿真,结果表明信号的时频特性得到了改善,该方法还适用于多分量非平稳信号的分析。     

Crucial factors determining the spatio-temporal distribution patterns of threeAthalia sawflies feeding on common cruciferous plants

Summary ThreeAthalia sawflies,A. japonica, A. rosae andA. infumata, feeding on cruciferous plants, coexist in Japan. However, it is not known what ecological strategies they use and what environmental factors are crucial to such strategies. I attempted to explain these questions by examining the relationship between the spatio-temporal distribution patterns of threeAthalia sawflies and their habitats in three districts (Lowland, Intermediate and Mountain). The three sawflies have different spatio-temporal distribution patterns, though they usually used common cruciferous plants.A. japonica was abundant in spring and autumn but disappeared during summer in all the districts. In the Lowland, populations ofA. rosae andA. infumata, like that ofA. japonica, crashed in summer. HoweverA. rosae occurred mainly in summer in the Intermediate and Mountain. AlthoughA. infumata occurred in the same seasons asA. rosae in all districts, population levels ofA. infumata were always lower than those ofA. rosae. The crucial factors controlling their population patterns were the availability of host plants and temperature. Population crashes ofA. rosae andA. infumata were due to food depletion, and those ofA. japonica were due to heat stress. On the other hand, their population patterns may be interpreted as phenological synchronization with their original host plants, though they all existed on common cruciferous plants. The three sawflies may have evolved different strategies to escape from unfavorable habitat conditions. Such strategies are speculated to be summer diapause inA. japonica, long distance migration inA. rosae, and local dispersal inA. infumata.     

关于非中心Laplace分布的密度函数

在本文中,对文[1]提出的广义Laplace分布进行了讨论,给出了广义Laplace分布的密度函数的解析表达式,同时进一步推导了非中心Laplace分布的密度函数表达式,最后对这类分布重要的数字特征在文中也被给出.