云南省蛭类及其生态研究

作者1991~1995年对云南省的蛭类进行了调查和采集,共获蛭类标本3000余条,经鉴定有4属9种为云南省的新分布,文章对该9种的形态及分布作了简述。     

我国居民收入差距扩大的原因及对策

论述居民收入差距问题主要表现为个人差距、城乡差距、行业差距和地区之间的差距。差距形成的原因主要有主体差异、社会转型、地域差别、政策因素、监控因素等。探讨解决我国居民收入差距问题的若干对策。     

Application of the Bayes’ theory to the failure rate evaluation of electrical apparatus

The Weibull distribution has been widely used in reliability fields. A mixed Weibull distribution represents a popu- lation that consists of several Weibull subpopulations. In this paper, a new approach which combines the least-squares method with Bayes’ theorem, takes advantage of the parameter estimation for single Weibull distribution is developed to estimate the pa- rameters of each subpopulation. The estimates given by this paper also satisfy the maximum likelihood equation. The estimates of the failure rate of the mixed Weibull population are given. An actual test data is computed by using the proposed method. The Kolmogorov-Smirnov goodness-of-fit test turns out that the proposed method yields more accurate result.     

Bayesian Quantile Structural Equation Models

Structural equation modeling is a common multivariate technique for the assessment of the interrelationships among latent variables. Structural equation models have been extensively applied to behavioral, medical, and social sciences. Basic structural equation models consist of a measurement equation for characterizing latent variables through multiple observed variables and a mean regression-type structural equation for investigating how explanatory latent variables influence outcomes of interest. However, the conventional structural equation does not provide a comprehensive analysis of the relationship between latent variables. In this article, we introduce the quantile regression method into structural equation models to assess the conditional quantile of the outcome latent variable given the explanatory latent variables and covariates. The estimation is conducted in a Bayesian framework with Markov Chain Monte Carlo algorithm. The posterior inference is performed with the help of asymmetric Laplace distribution. A simulation shows that the proposed method performs satisfactorily. An application to a study of chronic kidney disease is presented.     

Impact of commercial search engines and international databases on engineering teaching and research

For the last three decades, the engineering higher education and professional environments have been completely transformed by the ‘electronic/digital information revolution’ that has included the introduction of personal computer, the development of email and world wide web, and broadband Internet connections at home. Herein the writer compares the performances of several digital tools with traditional library resources. While new specialised search engines and open access digital repositories may fill a gap between conventional search engines and traditional references, these should be not be confused with real libraries and international scientific databases that encompass textbooks and peer-reviewed scholarly works. An absence of listing in some Internet search listings, databases and repositories is not an indication of standing. Researchers, engineers and academics should remember these key differences in assessing the quality of bibliographic ‘research’ based solely upon Internet searches.     

频率扩展对软件天线算法选择的影响

针对阵列协方差矩阵特征值分布的特点,从理论上分析了频率扩展对软件天线自适应算法性能的影响,并以MMSE算法为例进行仿真验证.最后对考虑频率扩展时软件天线算法的选择问题进行了讨论.     

按劳分配在社会主义市场经济条件下的变化与发展

在社会主义市场经济体制下，按劳分配在实施主体，客体范围，分配对象，分配尺度，调控手段等方面都呈现出有异于计划经济体制的一些新的变化与发展。     

从清产核资看高校国有资产管理

清产核资对高校国有资产管理具有重要意义．通过清产核资能够发现高校国有资产管理中的种种问题，进而找到解决问题的办法。本文结合清产核资工作实践，阐述了当前高校国有资产管理普遍存在的问题及防止国有资产流失，加强国有资产管理的措施。     

我国城市土地管理体制改革的基本构想——“三权分离”模式的理论依据及土地收益分配

根据马克思对地租理论的阐述,结合我国现阶段城市土地管理中存在的问题,指出实行城市土地管理体制“三权分离”是解决我国现阶段城市土地管理体制不顺和收益归属不清的有效途径。     

陕西地质灾害形成条件与对策探讨

陕西省是我国地质灾害较为严重的省份之一,其中滑坡、泥石流、崩塌易发区20多个,面积约12.5×104km2,占全省面积的60.8%,对陕西经济的发展造成了较大的影响.通过对陕西主要地质灾害形成条件的分析,为防治地质灾害提供一定客观依据,并针对这些地质灾害提出相应的对策,以便减少地质灾害对经济的影响.