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   118106篇
  免费   3168篇
  国内免费   1272篇
管理学   2052篇
劳动科学   27篇
民族学   1805篇
人才学   8篇
人口学   1611篇
丛书文集   16266篇
理论方法论   5177篇
综合类   87419篇
社会学   3706篇
统计学   4475篇
  2024年   202篇
  2023年   584篇
  2022年   862篇
  2021年   978篇
  2020年   1215篇
  2019年   1120篇
  2018年   1144篇
  2017年   1446篇
  2016年   1571篇
  2015年   2187篇
  2014年   5425篇
  2013年   6513篇
  2012年   6806篇
  2011年   8228篇
  2010年   6751篇
  2009年   6929篇
  2008年   7351篇
  2007年   9305篇
  2006年   9472篇
  2005年   8780篇
  2004年   8405篇
  2003年   8161篇
  2002年   6607篇
  2001年   5520篇
  2000年   3232篇
  1999年   925篇
  1998年   457篇
  1997年   369篇
  1996年   321篇
  1995年   266篇
  1994年   199篇
  1993年   169篇
  1992年   132篇
  1991年   116篇
  1990年   62篇
  1989年   56篇
  1988年   62篇
  1987年   19篇
  1986年   25篇
  1985年   96篇
  1984年   100篇
  1983年   71篇
  1982年   65篇
  1981年   59篇
  1980年   50篇
  1979年   52篇
  1978年   46篇
  1977年   16篇
  1976年   11篇
  1975年   6篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Nonparametric deconvolution problems require one to recover an unknown density when the data are contaminated with errors. Optimal global rates of convergence are found under the weighted Lp-loss (1 ≤ p ≤ ∞). It appears that the optimal rates of convergence are extremely low for supersmooth error distributions. To resolve this difficulty, we examine how high the noise level can be for deconvolution to be feasible, and for the deconvolution estimate to be as good as the ordinary density estimate. It is shown that if the noise level is not too high, nonparametric Gaussian deconvolution can still be practical. Several simulation studies are also presented.  相似文献   
62.
Summary The number of larvae reaching maturity within the gall ofAdelges japonicus was positively related to gall volume, and the relationship between the number of mature larvae and gall volume did not change with different densities of colonized larvae. The population changes in the bud galls ofA. japonicus were surveyed by collecting the galls, which did not suffer predation or parasitism within the galls, from young artificial plantations ofPicea jezoensis over two years. In the year when the density of colonized larvae was high, they suffered a 42% mortality within the galls, whereas mortality was nearly zero in the low density year. The numbers of larvae per gall were positively correlated with gall volume. The regression lines of the number of colonized larvae on gall volume did not differ significantly in the regression coefficients between the two years, whereas the intercept was significantly higher in the year when the density of colonized larvae was higher. However, different within-gall mortality nullified this difference, and the regression lines of the number of mature larvae on gall volume had no significant difference both in the regression coefficients and the intercepts. This suggests that the number of mature larvae per gall was limited by available resources within the gall which were positively related to gall volume. In 25% of the galls in which mature larvae inhabited, the space within the galls were completely filled by the larvae, indicating that space was one of the limiting resources. Gall volume also affected the number of adults that emerged from the gall and the potential number of their progeny.  相似文献   
63.
The robustness of Mauchly's sphericity test criterion when sampling from a mixture of two multivariate normal distributions is studied. The distribution of the sphericity test criterion when the sample covariance matrix has a non-central Wishart density of rank one is derived in terms of Meijer's G-functions; its distribution under the mixture model is then deduced. The robustness is studied by computing actual significance levels of the test under the mixture model using the critical values under the usual normal model.  相似文献   
64.
本文主要分析了HEIDENHAIN TNC 310数控铣床系统中圆弧铣削指令及螺纹铣削指令,对螺纹铣削功能进行延伸,扩展到圆弧三轴联动,并对螺纹铣削指令格式进行了修改,从而具有圆弧三轴联动铣削功能。  相似文献   
65.
Technology continues to challenge the public relations practitioner to find ways to inform key constituents. The new technology has given rise to the “new journalism” that includes a declining traditional media and exploding internet media filled with websites and bloggers. The question posed by this research asks: Does the public relations practitioner inherit the same protection offered by “qualified privilege” that is most often associated with the traditional “press” or “reporter?” The research lays a foundation with an examination of defamation and the defense of qualified privilege. The research concludes that if information gathered by the public relations practitioner meets the “intent” and “content” tests, the information qualifies as news. Passing the “news” test, the defense of “qualified privilege” also attaches to the public relations practitioner.  相似文献   
66.
In many developing regions, women and young girls spend several hours daily in the collection of natural resources. Still the link between these household resource strategies and stakeholder perceptions of development priorities remains unexplored. This project examines this association with survey data representative of the adult population from Ghana’s Coastal Region. Although natural resource scarcity and the sustainability of resource use represent key development challenges, there are others (e.g., energy, sanitation, employment, and educational opportunities). As such, even in the face of natural resource scarcity, individuals may place greater importance on other dimensions of development, especially if household resource strategies are perceived as relatively efficient. The analytical focus here is on water and the results suggest that gender roles shape household water collection strategies, while also shaping these strategies’ perceived opportunity costs. Specifically, Ghanian adults more often see drinking water provision as their primary development need when water sources are distant and/or when male household members collect water (particularly male heads). In the end, I argue that social science inquiry benefits by contextualizing social dynamics within environmental context, particularly within cultural settings in which human subsistence is intimately tied to the state of the natural environment.  相似文献   
67.
完善我国公司治理结构的路径探析   总被引:3,自引:0,他引:3  
公司治理结构在当代的发展趋势之一是利益相关者共同参与公司治理。我国公司股权集中、内部人控制严重、外部监督机制失灵的治理现状,决定了完善我国公司治理结构的有效路径应是构建利益相关者共同参与的公司治理结构,即将非股东的其他利益相关者引入公司治理,直接参与公司的经营、控制与监督。  相似文献   
68.
当代印度社会正发生着极大的变动,社会各阶层都在极力维护固有地位和宗教传统的稳定,并极力在这种变动中争取着自身社会利益的最大化。其中,南印度婆罗门种姓在逐步丧失传统的各项特权和优势地位的同时,也在努力适应、应对当代社会的新变化和新挑战。英国作家V.S.奈保尔的《印度:百万叛变的今天》一书提供了较为翔实、客观的口述史资料。以书中生活在孟买、班加罗尔、马德拉斯、加尔各达等南印度城市中的当代婆罗门阶层作为个案,可探究出其面对传统社会生活中的各个层面发生变动时的态度与应对及个体内在的深层原因,并在一定程度上考察社会变动与文化传统之间的互动关系。  相似文献   
69.
皮锡瑞《经学家法讲义》稿本的内容及其价值   总被引:1,自引:0,他引:1  
保存在《师伏堂经学杂记》中的一组经学文稿,是近代经学大师皮锡瑞晚年讲授"经学家法"课程时所编讲义原稿。这部《经学家法讲义》手稿对先秦至魏晋的经学变迁与得失作了简明扼要的疏理和评述,描绘出魏晋以前经学历史的基本轮廓,其中的新见卓识,更显示出这部隐秘至今的经学遗稿的学术价值。皮锡瑞还在稿中自道其"郑学"研究,有助于今人全面体认他融通今、古文经学的学术品性,确证他决非专治今文家言的经师。  相似文献   
70.
随着手机短信业务的发展,利用手机短信进行诈骗的现象也频繁发生。短信诈骗行为的泛滥,不仅严重侵犯了人们的财产权益,而且破坏了正常的社会经济秩序。为有效预防和遏制手机短信诈骗,应强化监管和打击,建立和完善手机号码实名制和储蓄实名制,加强宣传教育,多管齐下,进行综合治理。  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