首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   847篇
  免费   30篇
  国内免费   8篇
管理学   84篇
民族学   5篇
人口学   16篇
丛书文集   60篇
理论方法论   24篇
综合类   510篇
社会学   63篇
统计学   123篇
  2024年   1篇
  2023年   11篇
  2022年   13篇
  2021年   15篇
  2020年   16篇
  2019年   15篇
  2018年   9篇
  2017年   30篇
  2016年   19篇
  2015年   25篇
  2014年   47篇
  2013年   79篇
  2012年   57篇
  2011年   52篇
  2010年   58篇
  2009年   44篇
  2008年   51篇
  2007年   61篇
  2006年   48篇
  2005年   43篇
  2004年   39篇
  2003年   29篇
  2002年   26篇
  2001年   30篇
  2000年   14篇
  1999年   16篇
  1998年   9篇
  1997年   3篇
  1996年   3篇
  1995年   3篇
  1994年   9篇
  1993年   3篇
  1992年   1篇
  1990年   1篇
  1989年   1篇
  1988年   2篇
  1985年   1篇
  1983年   1篇
排序方式: 共有885条查询结果,搜索用时 15 毫秒
1.
介绍了对电站发动机组凝汽器进行状态监测和故障诊断的技术诊断自动化系统的研究和实现,实践证明,开发的系统对改善凝汽器性能、提高电站整体性能具有重要意义。  相似文献   
2.
研究生教育是高等教育结构中的高层次教育。文章围绕创建科学的研究生教育体系问题 ,从自主招生、导师队伍建设、学位授权点、学术监控以及办学理念等方面进行了探讨  相似文献   
3.
加强高校课程建设的基本途径   总被引:4,自引:0,他引:4  
目前,高校课程建设存在诸多问题,为此必须健全和完善课程建设的有效途径。本文从建立健全竞争机制、调动教师积极性,建立健全教学质量监控体系,加强课程实践基地建设等方面,阐述了高校课程建设的基本途径。  相似文献   
4.
Summary.  We discuss the inversion of the gas profiles (ozone, NO3, NO2, aerosols and neutral density) in the upper atmosphere from the spectral occultation measurements. The data are produced by the 'Global ozone monitoring of occultation of stars' instrument on board the Envisat satellite that was launched in March 2002. The instrument measures the attenuation of light spectra at various horizontal paths from about 100 km down to 10–20 km. The new feature is that these data allow the inversion of the gas concentration height profiles. A short introduction is given to the present operational data management procedure with examples of the first real data inversion. Several solution options for a more comprehensive statistical inversion are presented. A direct inversion leads to a non-linear model with hundreds of parameters to be estimated. The problem is solved with an adaptive single-step Markov chain Monte Carlo algorithm. Another approach is to divide the problem into several non-linear smaller dimensional problems, to run parallel adaptive Markov chain Monte Carlo chains for them and to solve the gas profiles in repetitive linear steps. The effect of grid size is discussed, and we present how the prior regularization takes the grid size into account in a way that effectively leads to a grid-independent inversion.  相似文献   
5.
加强课堂教学质量监控是提高学校教学质量的重要保证。端正对教学质量监控的认识 ,对其体系组成、工作方法进行研究探索 ,全面推进学生素质教育 ,培养新型人才 ,推动学校教学改革 ,提高教学质量效益有着重要的意义。  相似文献   
6.
转移价格是跨国公司在母公司与子公司、子公司与子公司之间进行内部贸易所采用的价格 ,是人为调高或调低价格来转移利润而采取的重要手段 ,使子公司经营处于“亏损”状态 ,从而使东道国蒙受巨大经济损失。为此 ,各东道国为维护本国的合法权益而采取多种防范和监控措施来限制跨国公司用转移价格来实现其整体总利润额的增加。  相似文献   
7.
本文主要观点是:建立选拔任用干部的监督机制是我国目前亟需解决的重要问题,它关系到是否能将有中国特色的社会主义事业不断推向前关键不是出了问题以后的解决方法,而是要加强对干部的主动监督,防止干部腐败变质.千秋大业在于用人,在选拔干部时应遵循已制定的科学规范,并从几方面加强监督,在工作中不断完善监督机制,同时要强调对干部的教育培训,并将其作为实施监督的基础性工作.  相似文献   
8.
畜产品质量安全监管研究综述   总被引:2,自引:0,他引:2  
随着经济的发展和社会的进步,畜产品在人们的日常生活中占有越来越重要的地位,目前我国对畜产品质量安全的监管还很不到位。文章总结了我国畜产品安全监管的现状,并介绍了国外畜产品安全监管的现状,通过比较找出我国监管的不足,从而进一步加强我国对畜产品质量安全的监管。  相似文献   
9.
The International Conference on Harmonisation guideline ‘Statistical Principles for Clinical Trials’ was adopted by the Committee for Proprietary Medicinal Products (CPMP) in March 1998, and consequently is operational in Europe. Since then more detailed guidance on selected topics has been issued by the CPMP in the form of ‘Points to Consider’ documents. The intent of these was to give guidance particularly to non‐statistical reviewers within regulatory authorities, although of course they also provide a good source of information for pharmaceutical industry statisticians. In addition, the Food and Drug Administration has recently issued a draft guideline on data monitoring committees. In November 2002 a one‐day discussion forum was held in London by Statisticians in the Pharmaceutical Industry (PSI). The aim of the meeting was to discuss how statisticians were responding to some of the issues covered in these new guidelines, and to document consensus views where they existed. The forum was attended by industry, academic and regulatory statisticians. This paper outlines the questions raised, resulting discussions and consensus views reached. It is clear from the guidelines and discussions at the workshop that the statistical analysis strategy must be planned during the design phase of a clinical trial and carefully documented. Once the study is complete the analysis strategy should be thoughtfully executed and the findings reported. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   
10.
The Lake Pontchartrain Basin in southeast Louisiana is an estuarine watershed encompassing New Orleans, Baton Rouge, and wetlands that are an integral part of Louisiana's unique culture. In recent decades rapid growth and poorly planned development have resulted in a decrease in water quality and habitat loss, especially in St. Tammany Parish on the north shore of Lake Pontchartrain. In 1989, the Lake Pontchartrain Basin Foundation (LPBF), an environmental, non-profit organization, was formed to address and rectify environmental issues in the Basin. LPBF accomplishes its mission through programs addressing water quality, habitat protection, geographic information science, public access, and education.LPBF used the recent, rapid development occurring in St. Tammany Parish as a case study to examine the relationship between land use, water quality, and development in the Basin by investigating habitat change/urbanization, development in flood plains, and water quality. Through the integration of LPBF programs, it was found that urbanization is having a devastating impact on the parish's natural habitats and severely degrading water quality. Using these results, LPBF is educating Basin citizens on the protection of their habitats and water quality to insure that these resources may be available for future generations.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号