微小钻头寿命分布规律研究

对微小钻头的寿命分布规律进行了研究,提出在本文的试验条件范围内,微小钻头寿命呈威布尔分布特点,并利用柯尔莫哥洛夫检验法进行了验证。     

用HPLE—荧光检测法研究维拉帕米在大鼠体内的药代动力学和组织分布特性

建立维拉帕米的反相高效液相色谱分析方法,并对其大鼠体内过程特性进行分析研完。方法:生物样品在碱性条件下经过正已烷一乙醚(30:70)提取,用Kromasil C_(18)反相柱(150mm×4.6mm,5μm),甲醇-水-三乙胺(70:30:0.1)为流动相,流速1.0mL.min~(-1),荧光检测波长为λ_(ex)275nm和λ_(ex)315nm。结果:方法回收率为92.3％～104.8％,测定血药浓度线性范围为8.5～85ng.mL~(-1)(r=0.9992),最低检测限0.6ng.ml~-。SD大鼠一次性灌胃盐酸维拉帕米片后血浆C-t曲线呈二室开放模型,达峰时间为(0.28±0.1)h。给药1.25h时,在主要的效应器官的浓度分布特点是:C_心>C_(大脑)>C_(小脑),在主要消除器官的浓度分布特点是:C_肝>C_肾>C_脾。结论:本法准确,灵敏度较高,可用于维拉帕米的体内过程研究。维拉帕米的肝首过效应应引起重视,主要由肾脏排泄。     

现代汉语通指的指称地位和分布位置

通指不是跟单指相对的概念,而是跟特指相对的概念,通指和特指构成定指范畴。通指主要分布在抽象事件句、判断句、"有"字句、抽象的形容词谓语句的主语位置上。通指主要的表现形式是单个名词,在抽象评议句中,可以是数量名短语,冠词性的"这"也常常表示通指。     

Effects of exposure to occupational violence and the mediating impact of fear

This paper examines the consequences of exposure to work-related violence and in particular, focuses upon the role of fear (of violence) as a mediating variable. The sample comprises UK public house licensees-individuals who manage public houses and hold the licence permitting the sale of alcoholic drinks on the premises. Questionnaires were sent to 479 licensees and a response rate of 51% was achieved. Each questionnaire measured exposure to a range of violent assaults, fear of violence, general well-being, job satisfaction and organizational commitment. Based upon a final sample of 242 pub licensees, regression analyses showed that as the severity of the violence to which licensees were exposed increased, so fear of becoming a victim and symptoms of impaired well-being increased, while job satisfaction and organizational commitment decreased. Hierarchical analyses showed that fear of violence fully mediated the negative impact of exposure upon each of these other variables. It is argued that the management of fear appraisals should be integrated into organizational responses to work-place violence.     

Improved minimax estimation of a normal precision matrix

Let S_{p × p} have a Wishart distribution with parameter matrix Σ and n degrees of freedom. We consider here the problem of estimating the precision matrix Σ^?1 under the loss functions L₁(σ) tr (σ) - log |σ| and L₂(σ) = tr (σ). James-Stein-type estimators have been derived for an arbitrary p. We also obtain an orthogonal invariant and a diagonal invariant minimax estimator under both loss functions. A Monte-Carlo simulation study indicates that the risk improvement of the orthogonal invariant estimators over the James-Stein type estimators, the Haff (1979) estimator, and the “testimator” given by Sinha and Ghosh (1987) is substantial.     

On diagnostic checking of the autoregressive conditional intensity model

The autoregressive conditional intensity model proposed by Russell (1998) is a promising option for fitting multivariate high frequency irregularly spaced data. The authors acknowledge the validity of this model by showing the independence of its generalized residuals, a crucial assumption of the model formulation not readily recognized by researchers. The authors derive the large‐sample distribution of the autocorrelations of the generalized residual series and use it to construct a goodness‐of‐fit test for the model. Empirical results compare the performance of their test with other off‐the‐shelf tests such as the Ljung–Box test. They illustrate the use of their test with transaction records of the HSBC stock.     

收入分配与个人努力程度的相关性研究

关于收入分配与经济增长的关系,学术界并没有定论。有些学者认为,现存收入分配政策是经济增长的必然结果;有些学者认为,确定的收入分配政策决定了经济增长的高度和深度。而所有的收入分配政策研究几乎都围绕着收入分配平等与否来展开。换句话说,主要是收入分配不平等有利于经济增长还是不利于经济增长。本文将从收入分配与个人努力程度的相关性的角度来阐述收入分配与经济增长之间的关系,从而为政府制定合理的收入分配政策提供理论依据。     

The Skew‐normal Distribution and Related Multivariate Families*

Abstract. This paper provides an introductory overview of a portion of distribution theory which is currently under intense development. The starting point of this topic has been the so‐called skew‐normal distribution, but the connected area is becoming increasingly broad, and its branches include now many extensions, such as the skew‐elliptical families, and some forms of semi‐parametric formulations, extending the relevance of the field much beyond the original theme of ‘skewness’. The final part of the paper illustrates connections with various areas of application, including selective sampling, models for compositional data, robust methods, some problems in econometrics, non‐linear time series, especially in connection with financial data, and more.     

Change-of-variance problem for linear processes with long memory

In this paper we investigate the asymptotic properties of the test statistics for detecting change-points in the variance of infinite moving average sequences with long memory. This research is partly supported by NSFC Grants and SRF for ROCS, SEM.     

试论性质命题主、谓项周延性的量词方法

性质命题主、谓项周延性“含糊”的问题如何解决,产生过表解法、图例法、与欧拉圈分析法等等.文章在诸多方法之外,提出了性质命题的量词方法,并阐述了量词方法的特征、规则及运用方式.