川佛手中总黄酮的超临界CO_2萃取工艺优化

采用超临界CO2萃取技术提取川佛手中的总黄酮,通过单因素分析和正交试验,确定了川佛手中总黄酮的最佳提取工艺参数,即萃取压力为30 MPa,萃取温度为50℃,料液比为100∶120 g/mL和萃取时间为2.0 h,在此条件下总黄酮的萃取率达到3.79﹪.     

高等学校内部质量保障体系的建立与完善

作为高等教育的组织者和实施者,高等学校应牢固树立以提高质量为核心的教育质量观,着力构建和不断完善内部质量保障体系。文章选取“211工程”高校作为研究对象,从顶层设计、核心内容、坚实保证、有效抓手入手,围绕办学定位、办学特色、办学条件、人才培养模式、优质资源整合、制度建设、文化建设等内容,提出了一系列旨在健全和完善高校内部质量保障体系的重要举措。     

Statistical Certification of Software Systems

Common software release procedures based on statistical techniques try to optimize the trade-off between further testing costs and costs due to remaining errors. We propose new software release procedures where the aim is to certify with a certain confidence level that the software does not contain errors. The underlying model is a discrete time model similar to the geometric Moranda model. The decisions are based on a mix of classical and Bayesian approaches to sequential testing and do not require any assumption on the initial number of errors.     

灾害中残疾人的媒介使用与信息沟通需求——以汶川地震为例

在灾害情况下,残疾人群所面临的沟通困境要远远高于正常人群,甚至连最基本的信息需求都无法得到保障。从2008年汶川地震中残疾人群媒介使用的特征和信息沟通需求来看,对这部分弱势群体的保护需要在法律和政策上给予更多的支持:改善信息发布和传递的渠道,使用新的技术手段,培养残疾人使用媒介的良好习惯。     

浅谈“神似”理论在唐诗英译中的重要作用——以《送友人》的两个英译版本为例

诗歌是一种独特的艺术表现形式,拥有优美的形式和丰富的内容,唐诗也不例外。英译唐诗时,应以再现诗作精神内容风貌为主,即以达到“神似”为翻译第一目标,才能更好地保持唐诗的原貌。本文选择李白《送友人》的两个英译本,分析了“神似”理论在唐诗英译中的重要作用。     

中美大学社团现状与管理模式比较——以河北工程大学与北卡罗来纳州立大学为例

[摘 要]通过对比河北工程大学和北卡州立大学学生社团的发展现状和管理模式,包括学生社团数目、组成及社团的审批、管理、经费、活动、资源等各个方面,对高校学生社团的发展和管理提出了几点建议。     

Embedding latent class regression and latent class distal outcome models into cluster-weighted latent class analysis: a detailed simulation experiment

Usually in latent class (LC) analysis, external predictors are taken to be cluster conditional probability predictors (LC models with external predictors), and/or score conditional probability predictors (LC regression models). In such cases, their distribution is not of interest. Class-specific distribution is of interest in the distal outcome model, when the distribution of the external variables is assumed to depend on LC membership. In this paper, we consider a more general formulation, that embeds both the LC regression and the distal outcome models, as is typically done in cluster-weighted modelling. This allows us to investigate (1) whether the distribution of the external variables differs across classes, (2) whether there are significant direct effects of the external variables on the indicators, by modelling jointly the relationship between the external and the latent variables. We show the advantages of the proposed modelling approach through a set of artificial examples, an extensive simulation study and an empirical application about psychological contracts among employees and employers in Belgium and the Netherlands.     

Adjusted empirical likelihood models with estimating equations for accelerated life tests

This article proposes an adjusted empirical likelihood estimation (AMELE) method to model and analyze accelerated life testing data. This approach flexibly and rigorously incorporates distribution assumptions and regression structures by estimating equations within a semiparametric estimation framework. An efficient method is provided to compute the empirical likelihood estimates, and asymptotic properties are studied. Real-life examples and numerical studies demonstrate the advantage of the proposed methodology.     

Adaptive cluster sampling with a data driven stopping rule

The adaptive cluster sampling (ACS) is a suitable sampling design for rare and clustered populations. In environmental and ecological applications, biological populations are generally animals or plants with highly patchy spatial distribution. However, ACS would be a less efficient design when the study population is not rare with low aggregation since the final sample size could be easily out of control. In this paper, a new variant of ACS is proposed in order to improve the performance (in term of precision and cost) of ACS versus simple random sampling (SRS). The idea is to detect the optimal sample size by means of a data-driven stopping rule in order to determine when to stop the adaptive procedure. By introducing a stopping rule the theoretical basis of ACS are not respected and the behaviour of the ordinary estimators used in ACS is explored by using Monte Carlo simulations. Results show that the proposed variant of ACS allows to control the effective sample size and to prevent from excessive efficiency loss typical of ACS when the population is less clustered than anticipated. The proposed strategy may be recommended especially when no prior information about the population structure is available as it does not require a prior knowledge of the degree of rarity and clustering of the population of interest.     

行政补偿立法思考

行政赔偿在行政领域起到了重要作用,目前获得行政赔偿的必要条件之一是行政主体违法行使职权,从行政相对人的角度考虑,在是否违法问题上大费周章没有必要,进一步从行政赔偿法是救济法的本质出发,优先考虑行政相对人的权益,将有关行政补偿内容纳入行政赔偿法律体系框架之中。