教育资源库检索结果的评价技术研究

对教育资源库的检索结果评价是各种教育资源库检索性能评价方案中最直接的方法。该文在总结目前教育资源库的四种主流检索方式的基础上,分析了传统信息检索的特征,结合教育资源库的网络化、海量化发展趋势,借鉴网络搜索引擎评价技术中的“相关性范畴”和“前X命中纪录查准率”概念,提出了一种基于考察替代查准率来对教育资源库检索结果进行评价的方法。     

Growth and Heat Resistance Kinetic Variation Among Various Isolates of Salmonella and its Application to Risk Assessment

The abilities of cells of a particular type of bacteria to leave lag phase and begin the process of dividing or surviving heat treatment can depend on the serotypes or strains of the bacteria. This article reports an investigation of serotype-specific differences in growth and heat resistance kinetics of clinical and food isolates of Salmonella. Growth kinetics at 19 degrees C and 37 degrees C were examined in brain heart infusion broth and heat resistance kinetics for 60 degrees C were examined in beef gravy using a submerged coil heating apparatus. Estimates of the parameters of the growth curves suggests a small between-serotype variance of the growth kinetics. However, for inactivation, the results suggest a significant between-serotype effect on the asymptotic D-values, with an estimated between-serotype CV of about 20%. In microbial risk assessment, predictive microbiology is used to estimate growth and inactivation of pathogens. Often the data used for estimating the growth or inactivation kinetics are based on measurements on a cocktail--a mixture of approximately equal proportions of several serotypes or strains of the pathogen being studied. The expected growth or inactivation rates derived from data using cocktails are biased, reflecting the characteristics of the fastest growing or most heat resistant serotype of the cocktail. In this article, an adjustment to decrease this possible bias in a risk assessment is offered. The article also presents discussion of the effect on estimating growth when stochastic assumptions are incorporated in the model. In particular, equations describing the variation of relative growth are derived, accounting for the stochastic variations of the division of cells. For small numbers of cells, the expected value of the relative growth is not an appropriate "representative" value for actual relative growths that might occur.     

县域经济发展的特色之路探析

结合泉州市的实践经验,探讨了县域发展特色经济的必要性和判别县域特色经济的基本准则,提出了县域发展特色经济应重点抓好4个环节:(1)选准特色产品,启动特色经济;(2)培育特色产业,壮大特色经济;(3)依托科技进步,提升特色经济;(4)塑造"适度"政府,服务特色经济。     

中国经济体制改革特点新探

中国二十多年的经济体制改革,在理论和实践上都积淀了丰硕的成果。这场改革具有两个鲜明特点:(1)从改革方式看,是“渐进式改革”;(2)从改革内容看,是“创新式改革”。两个特点交相辉映,共同演绎出了一曲举世瞩目的华彩乐章,构造了中华民族走向伟大复兴的重要前奏。充分认识和理解两个特点及其相互关系,是总结这场改革运动丰富经验的重要方面,并对于进一步深化经济体制改革和推进整个改革开放大业具有重要借鉴作用。     

中国现代性爱文学"性偏至"特质透视--中国现代文学心理批评研究之五

"性偏至"以宣示人性复苏和反叛旧教的"深刻的片面性"标示着中国现代性爱文学对西方以精神分析为代表人学思潮的接纳,标示着文学性深度探索的勇毅与执著,不仅具有深刻的批判意义,也寓示着重建健全的性爱结构的文化意义.     

浅论新形势下的反腐败斗争

从我国反腐败斗争的实际出发,分析了新形势下腐败斗争的四大特点,指出了搞好反腐败斗争的三大必要性,在此基础上提出了搞好反腐败斗争的四大对策。在江泽民为首的党中央领导下,按照“三个代表”的总要求,就一定能妥善地解决好反腐败问题。     

中国共产党与中国社会主义现代化

百余年中国现代化的历史进程表明 :中国不可能通过资本主义道路走向现代化 ,中国共产党领导中国人民走社会主义现代化道路是历史的抉择 ;中国现代化的发展必须以中国国情研究为基础 ,从中国社会实际出发 ,把马克思主义普遍真理同中国社会实际相结合 ;中国共产党在革命时期创立的新民主主义文化和在改革开放中创立的有中国特色社会主义文化 ,是对中国现代化进程中文化难题的两次回应 ;面向 2 1世纪 ,中国共产党必须进一步拓展对社会主义现代化建设的认识 ,进一步把握改革、开放与发展的大趋势 ,进一步加强对中国共产党自身的建设     

The estimation of derivatives of a nonparametric regression function when the data are correlated

A kernel estimator of a derivative of arbitrary order of a nonparametric average population curve is considered for a correlated-errors model with balanced replicate measurements at each design point. Asymptotic expansions of the mean squared error are derived for two classes of correlation functions in the model. Consistency, choice of smoothing parameter, and rates of convergence are examined for the important special cases of estimating the first and second derivatives.     

A Bivariate Generalization of Gamma Distribution

In this article, a bivariate generalisation of the gamma distribution is proposed by using an unsymmetrical bivariate characteristic function; an extension to the non central case also receives attention. The probability density functions of the product and ratio of the correlated components of this distribution are also derived. The benefits of introducing this generalized bivariate gamma distribution and the distributions of the product and the ratio of its components will be demonstrated by graphical representations of their density functions. An example of this generalized bivariate gamma distribution to rainfall data for two specific districts in the North West province is also given to illustrate the greater versatility of the new distribution.     

T型非线性电阻网络功率转移图的图解法

本文论述了利用非线性电阻的伏安特性，作出T型非线性电阻网络中任一元件的功率转移图的图解法．