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   163936篇
  免费   4421篇
  国内免费   1785篇
管理学   3786篇
劳动科学   33篇
民族学   2430篇
人才学   24篇
人口学   2113篇
丛书文集   21692篇
理论方法论   6842篇
综合类   120632篇
社会学   6626篇
统计学   5964篇
  2024年   279篇
  2023年   848篇
  2022年   1188篇
  2021年   1422篇
  2020年   1844篇
  2019年   1795篇
  2018年   1776篇
  2017年   2207篇
  2016年   2360篇
  2015年   3150篇
  2014年   7762篇
  2013年   9699篇
  2012年   9838篇
  2011年   11603篇
  2010年   9506篇
  2009年   9832篇
  2008年   10280篇
  2007年   12719篇
  2006年   12759篇
  2005年   11758篇
  2004年   11064篇
  2003年   10739篇
  2002年   8842篇
  2001年   7349篇
  2000年   4225篇
  1999年   1243篇
  1998年   660篇
  1997年   526篇
  1996年   451篇
  1995年   367篇
  1994年   283篇
  1993年   253篇
  1992年   207篇
  1991年   187篇
  1990年   107篇
  1989年   130篇
  1988年   78篇
  1987年   45篇
  1986年   48篇
  1985年   105篇
  1984年   144篇
  1983年   97篇
  1982年   96篇
  1981年   63篇
  1980年   59篇
  1979年   57篇
  1978年   51篇
  1977年   18篇
  1976年   12篇
  1975年   9篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
We examine the effects of the U.S.-Japan trade restraint on automobile prices and quality upgrading, for both Japanese imports and American small cars. From April 1981 to April 1984 the suggested retail price of all Japanese models increased by 15.8 percent, or 5.3 percent per year. We find that nearly the entire amount of this rise can be explained by the upgrading of individual models. This upgrading may benefit consumers who would purchase a luxury import in any case, but harms those who desire the basic imports. In addition to upgrading, we conclude that a second cost of the trade restraint has been to prevent the yen depreciation from being passed onto American consumers, in terms of lower imported auto prices. For U.S. small cars we find a 9.1 percent rise in the suggested retail price, or 3 percent per year, with a fraction of this amount due to model upgrading. If the yen depreciation had led to lower import prices without the trade restraint, then we expect that U.S. auto prices would have been lower, too.  相似文献   
72.
艺术的本质在于其精神性,从艺术和时代精神的相互关系中去确立划分艺术形态的标准是符合艺术本质的.按照艺术所包含的精神内容的不同,艺术形态可分为神性艺术、人性艺术和理性艺术,以丰富的艺术史例可以说明其特征.  相似文献   
73.
我国图书馆学已经历了近百年的发展历程,一代又一代图书馆学者们为此付出了辛勤的劳动,取得了丰富的学术成果。但我国图书馆学在新的形势下面临着知识经济、计算机技术和网络通讯的发展机遇与挑战,因此,图书馆学应以人为本,朝着知识化、数字化、网络化以及多元化的方向发展,成为各个学科整体发展的综合性应用科学。  相似文献   
74.
创新大学研究院管理体制和运行机制,对于推动大学知识和科技创新、加速科技成果产业化和社会化具有重要作用。为此,大学研究院在管理体制方面要实行理事会领导下的院长负责制和虚实结合的矩阵式组织模式。在运行机制方面应建立稳定有力的政策支持体系和科学民主的战略决策制度,建立以团队合作为主的科研队伍体系,建立以竞争为核心的人员聘用体系,建立科学的业绩考评和高效的人才激励制度,建立长效完备的投资渠道,建立积极有效的成果转化机制。  相似文献   
75.
宪法修改可分为全面修改和部分修改两种主要方式.全面修改和部分修改除了形式上的差别外,二者还存在认识论、修改评价等方面的重大区别.  相似文献   
76.
在专业、集约化生产越来越发达的条件下,人的全面发展如何可能?马克思"人的全面发展"理论的深层旨趣不仅仅是指能力的发展,更是追求社会的和谐.针对资本主义早期发展阶段劳动异化的状况,马克思主义经典作家强调变革旧的生产关系,促进人的发展.在现代化向纵深发展的当今时代,人的和谐发展则成为"人的全面发展"理论的主题.  相似文献   
77.
For testing the fit of the inverse Gaussian distribution with unknown parameters, the empirical distribution-function statistic A2 is studied. Two procedures are followed in constructing the test statistic; they yield the same asymptotic distribution. In the first procedure the parameters in the distribution function are directly estimated, and in the second the distribution function is estimated by its Rao-Blackwell distribution estimator. A table is given for the asymptotic critical points of A2. These are shown to depend only on the ratio of the unknown parameters. An analysis is provided of the effect of estimating the ratio to enter the table for A2. This analysis enables the proposal of the complete operating procedure, which is sustained by a Monte Carlo study.  相似文献   
78.
We discuss Bayesian analyses of traditional normal-mixture models for classification and discrimination. The development involves application of an iterative resampling approach to Monte Carlo inference, commonly called Gibbs sampling, and demonstrates routine application. We stress the benefits of exact analyses over traditional classification and discrimination techniques, including the ease with which such analyses may be performed in a quite general setting, with possibly several normal-mixture components having different covariance matrices, the computation of exact posterior classification probabilities for observed data and for future cases to be classified, and posterior distributions for these probabilities that allow for assessment of second-level uncertainties in classification.  相似文献   
79.
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   
80.
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   
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