多股流换热器传递函数系数的理论确定方法

用数值模拟方法对一四股流板翅式换热器分别施加流量、进口温度的阶跃变化，获得其出口温度动态的响应曲线；用理论方法研究了其传染函数的系数，从而得到了四股流换热器的传递函数，并对其结果进行了分析，所得的四股流板翅式换热器的传递函数系数炎其自动控制试验提供了理论依据。     

低闭合油藏油水同层储层含水饱和度新模型

G地区P油层由于闭合高度低，油水分异差，存在大量的油水同层，且该区油水同层与油层的物性、电性相近，使得传统的利用电阻率和孔隙度计算含水饱和度的方法失效；加上工区开发过程中采取多层合试，单层试油且产液性质为油水同出的层位较少，可供选择进行油水同层饱和度建模的样本较少，使得该区油水同层饱和度的准确计算成为储量提交的难点。针对这一问题，提出以少量的密闭取芯井为基础样本，首先应用相渗资料建立起产水率与含水饱和度关系，然后外推到常规取芯井获得含水饱和度的补充样本，进而通过优选孔隙度、电阻率比值等建模参数，构建了适用于研究区油水同层的饱和度计算新模型，通过统计，其平均相对误差仅为3.59%，满足了储量计算的精度要求。     

Identity for the NPMLE in Censored Data Models

We derive an identity for nonparametric maximum likelihood estimators (NPMLE) and regularized MLEs in censored data models which expresses the standardized maximum likelihood estimator in terms of the standardized empirical process. This identity provides an effective starting point in proving both consistency and efficiency of NPMLE and regularized MLE. The identity and corresponding method for proving efficiency is illustrated for the NPMLE in the univariate right-censored data model, the regularized MLE in the current status data model and for an implicit NPMLE based on a mixture of right-censored and current status data. Furthermore, a general algorithm for estimation of the limiting variance of the NPMLE is provided. This revised version was published online in July 2006 with corrections to the Cover Date.     

A Simple Formula for Calculating the "Mass Density" of a Lognormally Distributed Characteristic: Applications to Risk Analysis

Statements such as "80% of the employees do 20% of the work" or "the richest 1% of society controls 10% of its assets" are commonly used to describe the distribution or concentration of a variable characteristic within a population. Analogous statements can be constructed to reflect the relationship between probability and concentration for unvarying quantities surrounded by uncertainty. Both kinds of statements represent specific usages of a general relationship, the "mass density function," that is not widely exploited in risk analysis and management. This paper derives a simple formula for the mass density function when the uncertainty and/or the variability in a quantity is lognormally distributed; the formula gives the risk analyst an exact, "back-of-the-envelope" method for determining the fraction of the total amount of a quantity contained within any portion of its distribution. For example, if exposures to a toxicant are lognormally distributed with σ_{in x}= 2, 50% of all the exposure is borne by the 2.3% of persons most heavily exposed. Implications of this formula for various issues in risk assessment are explored, including: (1) the marginal benefits of risk reduction; (2) distributional equity and risk perception; (3) accurate confidence intervals for the population mean when a limited set of data is available; (4) the possible biases introduced by the uncritical assumption that extreme "outliers" exist; and (5) the calculation of the value of new information.     

山羊绒针织物起球过程的研究

通过分析山羊绒针织物起球机理,对山羊绒针织物的起球过程进行了观察研究,得出其起球过程的三个阶段:绒毛的产生、绒毛缠结成球和球的脱落.在起球过程中还进一步发现球的个数、球的重量以及起球程度随时间的变化而有所不同,但都会随着时间的增加达到最高值,然后随着时间的增加而减少.因而据此可做出山羊绒针织物的起球曲线,对起球曲线进行分析从而可得出山羊绒针织物摩擦起球的合适时间,对进行抗起球整理时的优化参数有指导意义.     

AIN基片上重掺杂硼的多晶硅膜电阻率温度特性

研究了ＡｌＮ基片上重掺杂硼的多晶硅膜电阻率温度特性。实验发现，膜电阻率随温度变化呈现出从ＮＴＣ过渡到ＰＴＣ的Ｕ型特性，转折温度ＴＭ的位置依赖工艺条件的变化。理论分析表明：晶界势垒使膜电阻率在温度变化上存在一个极小值，极小值对应的转折温度正比于晶界势垒。     

关于列表曲线插补问题的探讨

本文介绍了根据列表曲线的离散点计算各程序段初值的一般方法.     

圆锥曲线的光(声)学性质

本文以微分方程为主要工具揭示了圆锥曲线的光(声)学性质。     

Parenting as a Dynamic Process: A Test of the Resource Dilution Hypothesis

In this paper, we tested the resource dilution hypothesis, which posits that, because parenting resources are finite, the addition of a new sibling depletes parenting resources for other children in the household. We estimated growth curve models on the self‐reported parenting practices of mothers using four waves of data collected biennially between 1994 and 2000 on a nationally representative sample of 2,082 Canadian children aged 2 to 5 at initial interview and in continuously intact, two‐biological‐parent households. Results showed that when new children were added to the household, mothers exhibited declines in positive interaction, but increased their levels of consistent parenting. Taken together, these findings suggested that parenting resources were reallocated, rather than diluted, when family size increased.