R-W度规下的中微子方程及其分离

利用外微分给出了Ｒｏｂｅｒｔｓｏｎ－Ｗａｌｋｅｒ度规下的中微子方程并分离了该方程，为弯曲时空旋量场的研究提供了方便．     

就业机会成本对城镇地区已婚妇女择业行为的影响分析

本文基于补偿性工资差别假说,对影响城镇地区已婚妇女就业选择的决定因素进行了分析。计量结果表明,城镇地区已婚妇女的就业决策不仅取决于其保留工资率和市场工资率的相对大小,还受由就业类型本身所具的工作特性所引起的就业机会成本大小的影响;补偿性工资差别假说在非公有制部门中有较好的拟合性,对公有制部门则缺乏解释力。计量结果还发现,已婚妇女的择业行为与其配偶的收入和就业类型之间存在较强的相关关系。     

A biomedical application of latent class models with random effects

Traditional latent class modelling has been used in many biomedical settings. Unfortunately, many of these applications assume that the diagnostic tests are independent given the true disease status, an assumption that is often violated in practice. Qu, Tan and Kutner developed general latent class models with random effects to model the conditional dependence among multiple diagnostic tests. In this paper latent class modelling with random effects is used to estimate the sensitivity and specificity of six screening tests for detecting Chlamydia trachomatis in endocervical specimens from women attending family planning clinics.     

非线性因素对远场涡流探头特性的影响

采用线性和非线性有限元方法对带磁路和磁电组合屏蔽的远场涡流探头的信号──距离特性进行了计算机模拟，给出探头的信号──距离特性曲线。结果表明：铁磁材料的非线性因素导致激励电流密度与二次穿透区的位置直接相关联。     

“已经”和“曾经”的句法功能考察

本文从"已经"和"曾经"的句法功能入手,来考察"已经"和"曾经"与"了"的共现情况、修饰数量成分的情况、与副词"还"的共现情况,以其能明确"已经"和"曾经"的句法功能,并利于对外汉语教学.     

印刷电路板诊断信息流模型及其应用

从故障诊断的角度分析印刷电路板的原理图，建立了电路板的诊断信息流模型。模型反映了试验及试验与故障之间的观察关系。基于该模型讨论了印刷电路板的故障诊断问题，实例说明了模型的有效性，该模型还具有一定的处理多故障的能力。     

两个人的阿根廷

在南美洲南端的阿根廷,生活着两个人,一个是贵族,另一个是平民. 这里是地球上一个偏僻而安静的角落,接近南极,虽然在人们的地理概念中显得遥远,不可否认的是,它有着辽阔的国土、丰沛的降雨量、星罗棋布的河流、肥沃的冲积平原、高崇入云的山岭、无边无际的草原、漫长的海岸线.然而,生活在这里的欧洲人的后代并不甘心这样的宁静,他们似乎努力将自己的生活制造出一些声响来,想引起世界的注意和瞩目.大约有1/3的人口聚集在首都布宜诺斯艾丽斯,人们把这个世界最南端的超大城市建设得富丽堂皇.     

Comparison of Subsidy Schemes for Reducing Waiting Times in Healthcare Systems

This study analyzes subsidy schemes that are widely used in reducing waiting times for public healthcare service. We assume that public healthcare service has no user fee but an observable delay, while private healthcare service has a fee but no delay. Patients in the public system are given a subsidy s to use private service if their waiting times exceed a pre‐determined threshold t. We call these subsidy schemes (s, t) policies. As two extreme cases, the (s, t) policy is called an unconditional subsidy scheme if t = 0, and a full subsidy scheme if s is equal to the private service fee. There is a fixed budget constraint so that a scheme with larger s has a larger t. We assess policies using two criteria: total patient cost and serviceability (i.e., the probability of meeting a waiting time target for public service). We prove analytically that, if patients are equally sensitive to delay, a scheme with a smaller subsidy outperforms one with a larger subsidy on both criteria. Thus, the unconditional scheme dominates all other policies. Using empirically derived parameter values from the Hong Kong Cataract Surgery Program, we then compare policies numerically when patients differ in delay sensitivity. Total patient cost is now unimodal in subsidy amount: the unconditional scheme still yields the lowest total patient cost, but the full subsidy scheme can outperform some intermediate policies. Serviceability is unimodal too, and the full subsidy scheme can outperform the unconditional scheme in serviceability when the waiting time target is long.