汇率浮动后的资本管制策略

将资本因素引入供给函数,并考虑到外汇市场微观结构,可以构建一个弹性汇率制和资本有限流动下的宏观经济模型。模型分析显示:投资性资本管制放松会增大国际收支逆差和国内商品市场超额供给的矫正难度,投机性资本管制放松会增大外部失衡的矫正难度;弹性汇率制下,利率平价机制作用使国际市场利率变化的经济冲击随资本管制度降低而增强,更易发生汇率超调。由此引申的政策建议是,人民币汇率浮动化后,资本项目开放必须更加审慎,要适时进行外汇干预,保持国内外利率的动态一致,以防范资本盲目流动引发汇率超调、金融危机和经济动荡。     

Large deviations of multiclass M/G/1 queues

Consider a multiclass M/G/1 queue where queued customers are served in their order of arrival at a rate which depends on the customer class. We model this system using a chain with states represented by a tree. Since the service time distribution depends on the customer class, the stationary distribution is not of product form so there is no simple expression for the stationary distribution. Nevertheless, we can find a harmonic function on this chain which provides information about the asymptotics of this stationary distribution. The associated h‐transformation produces a change of measure that increases the arrival rate of customers and decreases the departure rate thus making large deviations common. The Canadian Journal of Statistics 37: 327–346; 2009 © 2009 Statistical Society of Canada     

Designing sampling plans to capture rare objects

This article focuses on two‐phase sampling designs for a population with unknown number of rare objects. The first phase is used to estimate the number of rare or potentially rare objects in a population, and the second phase to design sampling plans to capture a certain number or a certain proportion of such type of objects. A hypergeometric‐binomial model is applied to infer the number of rare or potentially rare objects and Monte Carlo simulation based approaches are developed to calculate needed sample sizes. Simulations and real data applications are discussed. The Canadian Journal of Statistics 37: 417–434; 2009 © 2009 Statistical Society of Canada     

改性天然丝光沸石结构与性能的研究

本文对天然丝光沸石依次进行盐酸脱铝,铵离子交换,510℃焙烧,再铵离子交换,815℃焙烧,二次盐酸脱铝,稀土离子交换等一系列处理。用热分析,X—射线衍射和红外光谱等方法讨论了上述处理对催化剂的结构和性能的影响。经上述处理的天然丝光沸石可适用于催化裂化反应。为天然丝光沸石代替合成丝光沸石作裂化催化剂提供了依据。     

使胶状稀土氢氧化物成大颗粒沉淀与除去杂质钡、钙、镁的研究

本文从理论上探讨了使胶状稀土氢氧化物沉淀完全和除去杂质钡、钙、镁的原理,并将其应用于从稀土矿中提取高纯度混合稀土氧化物的工艺生产中。实验结果表明,在控制调节pH等条件下,用絮凝法能使胶状氢氧化稀土成大颗粒沉淀而与杂质钡、钙、镁完全分离。     

南薯88蔓割病病原特性及品种间致病性研究

经柯赫氏证病律验证,引起甘薯新品种南薯88“三烂”(烂苕鼻子、烂薯块、烂藤)的主要原因是甘薯蔓割病,由Fusarium oxysporum shl·f·batatas(尖镰孢菌甘薯专化型)引起。为害藤蔓时,叶昧、叶肉发黄,老叶脱落,贮藏期引起大量烂薯。人工接种,对南薯88、徐薯18、胜利百号、81—13、83—31、绵粉一号、南京R(5—3)、88—3735、87—1227、88—1447、87—2336、88—1650、828—34、88—2859等14个品种进行致病性测定。经薯块和藤蔓接仲、无菌土盆栽、田间小区试验表明,南薯88蔓割病的发病率、病斑面积,病薯个数、分离出Fusaryium oxysporum shl·f·sp·batatas的百分率均显著高于其它供试品种,薯块接种发病后,南薯88的病斑扩展较其它品种快。病菌以菌丝体和厚垣孢子在病薯及土壤中越冬;由伤口和茅管侵入。无伤和愈伤组织不能侵入;通过病种薯和土壤传播。     

吴骞与《临安志》研究

吴骞是清代著名徽州籍藏书家,一生藏书无数,曾建造拜经楼以藏书。《临安志》为吴骞藏书的精华,其也曾以此为荣。通过对《临安志》的收藏,吴骞与黄丕烈、陈缱等人频繁往来,互相借鉴、诗文唱和,从而构成了藏书史上的一段佳话。遗憾的是,吴骞去世后,其所藏《临安志》开始流散并被递藏：其中,（淳祜）《临安志》被陆心源递藏,现藏日本静嘉堂文库;（成淳）《临安志》被丁氏递藏,现藏南京图书馆;（乾道）《临安志》现藏于台湾中央研究院图书馆。     

中年高级知识分子健康状况的社会人口学分析

本文使用2004年"北京市中年高级专业技术人才健康状况调查"资料,从社会医学和社会人口学的角度比较了北京市中年高级知识分子与普通人群之间健康水平的差异;探讨了影响知识分子健康状况的个人和社会环境因素。结果显示,其一,当以慢性疾病来衡量生理健康时,知识分子的健康状况低于一般人群,但二者的生活质量自评没有显著差异。其二,社会人口学因素对这两方面健康的作用有同有异。工作和生活压力是影响人们身心健康的至关重要因素之一,但大部分因素对健康的影响因健康层面和人群而异。     

A Risk Assessment of Campylobacteriosis and Salmonellosis Linked to Chicken Meals Prepared in Households in Dakar,Senegal

We used a quantitative microbiological risk assessment model to describe the risk of Campylobacter and Salmonella infection linked to chicken meals prepared in households in Dakar, Senegal. The model uses data collected specifically for this study, such as the prevalence and level of bacteria on the neck skin of chickens bought in Dakar markets, time‐temperature profiles recorded from purchase to consumption, an observational survey of meal preparation in private kitchens, and detection and enumeration of pathogens on kitchenware and cooks’ hands. Thorough heating kills all bacteria present on chicken during cooking, but cross‐contamination of cooked chicken or ready‐to‐eat food prepared for the meal via kitchenware and cooks’ hands leads to a high expected frequency of pathogen ingestion. Additionally, significant growth of Salmonella is predicted during food storage at ambient temperature before and after meal preparation. These high exposures lead to a high estimated risk of campylobacteriosis and/or salmonellosis in Dakar households. The public health consequences could be amplified by the high level of antimicrobial resistance of Salmonella and Campylobacter observed in this setting. A significant decrease in the number of ingested bacteria and in the risk could be achieved through a reduction of the prevalence of chicken contamination at slaughter, and by the use of simple hygienic measures in the kitchen. There is an urgent need to reinforce the hygiene education of food handlers in Senegal.     

Use of Risk Assessment and Likelihood Estimation to Analyze Spatial Distribution Pattern of Respiratory Infection Cases

Obvious spatial infection patterns are often observed in cases associated with airborne transmissible diseases. Existing quantitative infection risk assessment models analyze the observed cases by assuming a homogeneous infectious particle concentration and ignore the spatial infection pattern, which may cause errors. This study aims at developing an approach to analyze spatial infection patterns associated with infectious respiratory diseases or other airborne transmissible diseases using infection risk assessment and likelihood estimation. Mathematical likelihood, based on binomial probability, was used to formulate the retrospective component with some additional mathematical treatments. Together with an infection risk assessment model that can address spatial heterogeneity, the method can be used to analyze the spatial infection pattern and retrospectively estimate the influencing parameters causing the cases, such as the infectious source strength of the pathogen. A Varicella outbreak was selected to demonstrate the use of the new approach. The infectious source strength estimated by the Wells‐Riley concept using the likelihood estimation was compared with the estimation using the existing method. It was found that the maximum likelihood estimation matches the epidemiological observation of the outbreak case much better than the estimation under the assumption of homogeneous infectious particle concentration. Influencing parameters retrospectively estimated using the new approach can be used as input parameters in quantitative infection risk assessment of the disease under other scenarios. The approach developed in this study can also serve as an epidemiological tool in outbreak investigation. Limitations and further developments are also discussed.