Russian Bioscience Publications and Journals in International Bibliometric Databases

This article analyzes shares and rankings of Russian bioscience publications and journals in international bibliometric databases. Studying scholarly output, international collaboration, and the share of Russian papers both in national and international journals enables the authors to highlight the current state of biological science and journals in Russia and outline some pronounced trends. A comparative analysis with the leading countries confirms good representation of Russian bioscience journals among other international serials. Certain problems remain unsolved, however: low impact factors, overrepresentation of national papers, and poor online services. Thus, Russian publishers should correct their editorial policy to improve availability and performance of serials.     

陕西与全国生猪生产同步性研究

同步性是我国生猪生产波动的重要特征之一.利用相关系数法和同步系数法,结合1952-2007年年末生猪存栏量数据,对陕西与全国生猪生产波动的同步性特征进行了比较分析.结果显示:同步系数法的测度结果比相关系数更科学;陕西与全国生猪生产波动的同步性程度达到0.763 6,且这种同步性具有越来越强的变化趋势;以陕西省作为全国生猪生产波动的一个观测点,分析全国生猪生产波动趋势具有一定的科学性.     

农村地区“读书无用论”现象探析

分析了1999年高等学校大规模扩招之后,大学生面临就业风险,"读书无用论"之风又在农村地区刮起。指出其原因是教育投入成本超出了农民的经济承受能力,教育投入和产出不成正比,教育中不公平现象的存在。认为多途径增加农民收入,建立和完善贫困生资助体系;提高教学质量,加强就业指导;进一步完善高等教育收费制度是破解此问题的3条路径。     

输出假设理论对促进中介语发展的实践指导

在分析大学生英语课堂学习特点与大学生中介语发展障碍的成因的基础上,指出可理解语言输出在二语习得中扮演着重要角色,传统重输入轻输出的外语教学模式不利于中介语发展,缺乏语言输出成为中介语发展的瓶颈.将输出假设理论应用于课堂教学的实践表明,在抓住课堂教学关键期、增加输入有效性的前提下,减少学生对规避学习策略的依赖,创设元语言环境,鼓励有效的语言输出,以输出性活动提升学生对自身中介语系统的关注,有利于提高教学效果.     

输出与理解任务对听力理解和词汇习得的作用

通过实证研究的方法,考察输出任务与理解任务在听力理解和产出性词汇习得效果上的差异,及哪种输出任务的听力理解与词汇习得效果最好。研究结果表明:(1)输出任务的听力理解效果均优于理解任务;且目标词合作输出的效果最好,目标词个人输出和无目标词个人输出之间无显著差异。(2)在产出性词汇的习得与保持上,含目标词的输出任务都明显好于理解任务,但无目标词输出任务与理解任务之间不存在显著差异;且目标词合作输出的效果最好,其次是目标词个人输出,再次是无目标词个人输出。     

基于修正R/S模型族的中国上市家族企业股票风险特征研究

本文利用股票风险分析模型修正R/S模型,利用我国上市家族企业和非家族企业的30只(15对)个股2006年1月4日~2010年1月4日期间的样本数据进行建模分析,来对我国上市家族企业的风险特征进行分析研究。研究结果表明:上市家族企业价格持续状态明显弱于上市非家族企业,家族企业对冲击的消化能力较强;股价波动的关联性,股价的波动一定程度上受历史信息的影响。这些研究发现对投资者来说,掌握历史信息对投资决策是有帮助的。     

葡萄枝培养料栽培黑木耳的试验研究

研究皖北葡萄产区黑木耳栽培过程中,不同葡萄枝屑培养料配方对黑木耳生长发育和产量的影响。结果表明:不同配方培养料对黑木耳的菌丝生长速度和生长势、生育期、产量及生物学效率等均有较大的影响,其中,以60%葡萄枝屑+18%玉米芯配方效果最好。该配方培养料的菌丝生长势最强,子实体形态最佳,产量最高;且在主料中添加玉米粉,菌丝生长健壮,原基形成快,菇耳产量及商品率高。     

Prediction from a normal model using a generalized inverse Gaussian prior

In this paper, we derive prediction distribution of future response(s) from the normal distribution assuming a generalized inverse Gaussian (GIG) prior density for the variance. The GIG includes as special cases the inverse Gaussian, the inverted chi-squared and gamma distributions. The results lead to Bessel-type prediction distributions which is in contrast with the Student-t distributions usually obtained using the inverted chi-squared prior density for the variance. Further, the general structure of GIG provides us with new flexible prediction distributions which include as special cases most of the earlier results obtained under normal-inverted chi-squared or vague priors.     

投入产出模型的动态化

建立合理、实用的动态投入产出模型,一直是投入产出理论研究的重要课题。本文把静态列昂节夫投入产出模型和宏观经济学的收入决定理论结合起来,得到一个基于变结构控制的动态投入产出模型。     

Simple moment-based inferences of generalized concordance correlation

We proposed two simple moment-based procedures, one with (GCCC1) and one without (GCCC2) normality assumptions, to generalize the inference of concordance correlation coefficient for the evaluation of agreement among multiple observers for measurements on a continuous scale. A modified Fisher's Z-transformation was adapted to further improve the inference. We compared the proposed methods with U-statistic-based inference approach. Simulation analysis showed desirable statistical properties of the simplified approach GCCC1, in terms of coverage probabilities and coverage balance, especially for small samples. GCCC2, which is distribution-free, behaved comparably with the U-statistic-based procedure, but had a more intuitive and explicit variance estimator. The utility of these approaches were illustrated using two clinical data examples.