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   12268篇
  免费   564篇
  国内免费   148篇
管理学   543篇
民族学   194篇
人才学   1篇
人口学   247篇
丛书文集   1220篇
理论方法论   752篇
综合类   7091篇
社会学   1642篇
统计学   1290篇
  2024年   12篇
  2023年   74篇
  2022年   88篇
  2021年   143篇
  2020年   228篇
  2019年   351篇
  2018年   313篇
  2017年   364篇
  2016年   329篇
  2015年   332篇
  2014年   628篇
  2013年   1407篇
  2012年   792篇
  2011年   808篇
  2010年   697篇
  2009年   630篇
  2008年   751篇
  2007年   801篇
  2006年   785篇
  2005年   663篇
  2004年   622篇
  2003年   579篇
  2002年   506篇
  2001年   397篇
  2000年   278篇
  1999年   119篇
  1998年   55篇
  1997年   36篇
  1996年   49篇
  1995年   29篇
  1994年   17篇
  1993年   15篇
  1992年   13篇
  1991年   8篇
  1990年   12篇
  1989年   9篇
  1988年   7篇
  1987年   7篇
  1986年   6篇
  1985年   4篇
  1984年   1篇
  1983年   3篇
  1982年   2篇
  1981年   3篇
  1979年   2篇
  1978年   2篇
  1977年   1篇
  1976年   1篇
  1975年   1篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
Abstract.  In this paper, we study the statistical interpretation of forensic DNA mixtures with related contributors in subdivided populations. Compact general formulae for match probabilities are obtained for two situations: a relative of one tested person is an unknown contributor of a DNA mixture; and two related unknowns are contributors. The effect of kinship and population structure is illustrated using a real case example.  相似文献   
42.
20世纪《红楼梦》语言研究综述   总被引:1,自引:1,他引:0  
20世纪时《红楼梦》语言研究的成果显著,诸如曹雪芹的语言观,《红楼梦》语言的总成就、语言的地域色彩、人物的语言,它对俗语的运用、语言艺术的手法、它的语言的情绪,《红楼梦》语言与社会文化的关系、它的语言的传承与创新等,都得到不同程度的研究,为我们正确认识《红楼梦》的成就和在新世纪的研究打下良好的基础。  相似文献   
43.
Missing data, and the bias they can cause, are an almost ever‐present concern in clinical trials. The last observation carried forward (LOCF) approach has been frequently utilized to handle missing data in clinical trials, and is often specified in conjunction with analysis of variance (LOCF ANOVA) for the primary analysis. Considerable advances in statistical methodology, and in our ability to implement these methods, have been made in recent years. Likelihood‐based, mixed‐effects model approaches implemented under the missing at random (MAR) framework are now easy to implement, and are commonly used to analyse clinical trial data. Furthermore, such approaches are more robust to the biases from missing data, and provide better control of Type I and Type II errors than LOCF ANOVA. Empirical research and analytic proof have demonstrated that the behaviour of LOCF is uncertain, and in many situations it has not been conservative. Using LOCF as a composite measure of safety, tolerability and efficacy can lead to erroneous conclusions regarding the effectiveness of a drug. This approach also violates the fundamental basis of statistics as it involves testing an outcome that is not a physical parameter of the population, but rather a quantity that can be influenced by investigator behaviour, trial design, etc. Practice should shift away from using LOCF ANOVA as the primary analysis and focus on likelihood‐based, mixed‐effects model approaches developed under the MAR framework, with missing not at random methods used to assess robustness of the primary analysis. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   
44.
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   
45.
高铭暄教授是我国当代著名的法学家和法学教育家,是新中国刑法学的主要奠基者和开拓者。在刑事立法、刑法学研究方法以及刑法专门问题上都有自己的真知灼见,逐步形成自己特有的刑法思想体系,为新中国刑事法治的建立、发展与完善奠定了坚实的基础,为新中国刑法学科的建构、繁荣与拓展作出了卓越的贡献。  相似文献   
46.
矛盾分析法在科学认识中的具体应用,可作多侧面的展开,形成多方面的更为具体的科学方法。这些具体科学方法可概括为,矛盾的定性分析法、矛盾的定位分析法、矛盾的定点分析法、矛盾的定量分析法、矛盾的定势分析法、矛盾的历史过程分析法、矛盾的逻辑过程分析法、矛盾的系统分析法、矛盾的对立面互补分析法等等.它们均体现哲学方法与具体科学方法的一致性。  相似文献   
47.
西方生育文化发展研究   总被引:2,自引:1,他引:1  
西方生育文化源于原始的生殖崇拜,经历了由文艺复兴前生育文化、文艺复兴后生育文化和20世纪中期以来生育文化等几个阶段的发展,每一阶段上的生育观念、生育习俗、生育制度、生育理论都呈现出不同变化及特点。  相似文献   
48.
新时期高等学校教师培训工作的思考   总被引:1,自引:0,他引:1  
分析了高等学校教师培训工作的现状,即不完全适应时代发展的需要;不完全适应我国加入WTO后高等教育与国际接轨的需要;不完全适应高等教育自身深化改革和发展的需要;不完全适应教师参训的个性愿望的需要。针对高等学校教师培训实际工作中存在重学历培训,轻师德培养;对教师创新能力、实践能力的培养不够重视;经费短缺,内容陈旧,考核机制不够完善等问题,提出了健全规章,实行依法培训;加强师德建设,采取多种形式,提高教师综合素质;设立专项培训经费及建立健全教师培训的激励机制的对策。  相似文献   
49.
文章分析了我国入世后,在关税壁垒和许多非关税壁垒对我国外贸发展的影响日渐减弱的情况下,WTO框架下的技术性贸易壁垒对我国外贸的不利影响.并提出四项对策:提高国内对技术性贸易壁垒的认识和了解,使企业重视技术性贸易壁垒的不断变化;将技术性贸易壁垒转化为标准化的推进器,提高产品质量;强化知识产权保护,使企业能不断提高自身的技术水平;实施"走出去"策略,规避繁苛的技术贸易壁垒,以期对我国外贸实践有所助益.  相似文献   
50.
Impacts of complex emergencies or relief interventions have often been evaluated by absolute mortality compared to international standardized mortality rates. A better evaluation would be to compare with local baseline mortality of the affected populations. A projection of population-based survival data into time of emergency or intervention based on information from before the emergency may create a local baseline reference. We find a log-transformed Gaussian time series model where standard errors of the estimated rates are included in the variance to have the best forecasting capacity. However, if time-at-risk during the forecasted period is known then forecasting might be done using a Poisson time series model with overdispersion. Whatever, the standard error of the estimated rates must be included in the variance of the model either in an additive form in a Gaussian model or in a multiplicative form by overdispersion in a Poisson model. Data on which the forecasting is based must be modelled carefully concerning not only calendar-time trends but also periods with excessive frequency of events (epidemics) and seasonal variations to eliminate residual autocorrelation and to make a proper reference for comparison, reflecting changes over time during the emergency. Hence, when modelled properly it is possible to predict a reference to an emergency-affected population based on local conditions. We predicted childhood mortality during the war in Guinea-Bissau 1998-1999. We found an increased mortality in the first half-year of the war and a mortality corresponding to the expected one in the last half-year of the war.  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