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151.
首先归纳了三板市场的特征,从历史、理论、现实三个角度论证了在我国设立三板市场的必要性,构想了我国三板市场的发展思路和发展步骤,分析了发展的障碍,进而提出了相应对策.  相似文献   
152.
高新技术企业的创业正在我国兴起。对高新技术企业创业的时代背景———知识经济的若干特点作出分析 ,同时参考美国硅谷发展的经验 ,结合我国实际情况探讨了高新技术企业创业的必要条件  相似文献   
153.
This study investigates the influence of high school sector on educational success in Japan. A range of previous research on disparities among high schools has revealed that high school rank (based on the academic ability of pupils, etc.) originated from the democratization of high school. However, given that the democratization of high school is supported by private high schools, high school sector may become a factor for high school ranking. The data used for the analysis are the 2005 National Survey of Social Stratification and Social Mobility (SSM) in Japan. The results indicate that students who enter private high schools have lower academic ability than students who enter public high schools. By contrast, private high school students have greater educational success than public high school students. Moreover, this study reveals that private high school students are generally from a higher social class than public high school students. Given that the use of entrance examinations for private junior high schools has been increasing since the 1990s, in the future, the effect of private schools on educational success may become stronger in not only high schools but also junior high schools. This study thus emphasizes the importance of paying greater attention to the relationship between educational success and the private and public school sectors.  相似文献   
154.
Abstract. In this study we are concerned with inference on the correlation parameter ρ of two Brownian motions, when only high‐frequency observations from two one‐dimensional continuous Itô semimartingales, driven by these particular Brownian motions, are available. Estimators for ρ are constructed in two situations: either when both components are observed (at the same time), or when only one component is observed and the other one represents its volatility process and thus has to be estimated from the data as well. In the first case it is shown that our estimator has the same asymptotic behaviour as the standard one for i.i.d. normal observations, whereas a feasible estimator can still be defined in the second framework, but with a slower rate of convergence.  相似文献   
155.
三牙轮钻头轴承的使用寿命直接决定了钻头的寿命。为了弄清三牙轮钻头轴承的失效形式、原因及机理,进一步提高三牙轮钻头轴承的寿命,分别对现场失效的三牙轮钻头轴承进行宏观和微观分析。结果表明,密封系统失效是轴承失效的主要原因之一。同时,轴承所受载荷过大且分布不均,温度过高导致材料表面金属强度和耐磨性降低,以及轴承与牙轮之间配合间隙过大,工作时晃动导致受力不均等原因也是造成牙轮钻头轴承的快速失效的主要原因。  相似文献   
156.
Abstract

In this note, we give explicit expressions of moment generating functions for integer valued random variables in both univariate and multivariate cases, which extend the results obtained by Nadarajah and Mitov [Communications in Statistics–Theory and Methods, 32, 2003, 47–60] and more recently by Chakraborti, Jardim and Epprecht [The American Statistician, 2017], Kwong and Nadarajah [Communications in Statistics–Theory and Methods, 2017]. Some examples are also discussed.  相似文献   
157.
SUMMARY

The American view that adolescent-adult sexual relations are by definition “child sexual abuse” has spread throughout the Western world and reshaped public policy. This paper, originally presented as a talk, examines the scientific validity of this view. A historical perspective traces the conflation of the adolescent experience with rape, incest, and that of the young, prepubescent child. Biological and cognitive perspectives support the view that adolescents have more in common with adults than children. Sweeping claims that adolescents react as children are said to is critically tested by examining two types of relations-those between heterosexual teenage boys and women and those between gay or bisexual teenage boys and men. Non-clinical empirical data show overwhelmingly that such relations are characterized mostly by positive reactions based on consent if not initiative on the part of the minor, with perceived benefit rather than harm as a correlate. It is concluded that the American view is false, and that public policy that heightens official reaction to such relations, such as that currently proposed by the European Union, are either misinformed or disingenuous in alleging to protect when the motive is to control adolescents.  相似文献   
158.
利用物理学原理对算法的隐含并行性进行了分析,提出算法的不确定性和高熵态是隐含并行性出现的根源,但算法的隐含并行性会导致算法结果的不确定性。智能算法中先验知识确定程序的搜索方向,隐含并行性提供了对解空间的高速并行搜索,为研究和设计智能算法提供了理论基础。提高算法的先验信息量和隐含并行能力可以得到具备较高智能水平的算法。  相似文献   
159.
当前高等教育的地位和作用发生了变化 ,要办好我国的高等教育 ,应坚持以“三个代表”为指导 ,正确把握其发展方向 ,着力解决相关问题  相似文献   
160.
针对有代表性密闭取芯岩芯平行样,分别进行油水饱和度和油水高速离心驱替实验核磁共振分析,定量获得 储层目前剩余油饱和度、采出油相对量、可动油饱和度及驱油效率上限等参数,对比各参数建立储层可动剩余油饱和 度核磁共振分析方法。研究表明,建立岩芯饱和油束缚水状态和水驱油的最佳离心力分别为2.250 MPa 和0.220 MPa, 4 个渗透率级别(>50、[10,50)、[1,10)和<1 mD)储层采出油饱和度分别为23.49%、16.81%、8.70% 和9.99%,可动油 饱和度分别为50.34%、43.76%、29.67% 和22.89%,可动剩余油饱和度分别为26.85%、26.95%、20.97% 和12.90%,由 于储层非均质性影响,大于10 mD 储层采出油明显高于10 mD 以下储层,但大于10 mD 储层可动油饱和度较高,故可 动剩余油饱和度也较高,小于1 mD 的储层可动剩余油明显低于其他储层。  相似文献   
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