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   107176篇
  免费   2568篇
  国内免费   173篇
管理学   13053篇
劳动科学   60篇
民族学   1111篇
人才学   40篇
人口学   7116篇
丛书文集   5739篇
教育普及   1篇
理论方法论   10242篇
综合类   10001篇
社会学   42485篇
统计学   20069篇
  2023年   582篇
  2022年   553篇
  2021年   780篇
  2020年   1708篇
  2019年   2378篇
  2018年   2289篇
  2017年   3510篇
  2016年   2605篇
  2015年   2579篇
  2014年   3278篇
  2013年   19726篇
  2012年   3186篇
  2011年   3369篇
  2010年   3258篇
  2009年   3585篇
  2008年   3220篇
  2007年   3280篇
  2006年   3549篇
  2005年   3419篇
  2004年   2740篇
  2003年   2330篇
  2002年   2475篇
  2001年   2416篇
  2000年   2060篇
  1999年   1932篇
  1998年   1637篇
  1997年   1498篇
  1996年   1462篇
  1995年   1443篇
  1994年   1376篇
  1993年   1365篇
  1992年   1343篇
  1991年   1255篇
  1990年   1208篇
  1989年   1030篇
  1988年   1121篇
  1987年   990篇
  1986年   872篇
  1985年   1052篇
  1984年   1122篇
  1983年   1002篇
  1982年   921篇
  1981年   855篇
  1980年   805篇
  1979年   863篇
  1978年   774篇
  1977年   691篇
  1976年   647篇
  1975年   618篇
  1974年   516篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
在重整程序中,自动冻结制度有其独特的功能。无论是自动冻结主义还是裁定冻结主义,其适用范围都必须合理界定。我国现行企业破产法和新的破产法草案尽管对自动冻结制度有所规定,但不够系统、完善,有必要从适用范围、例外与解除等方面加以完善。  相似文献   
92.
Summary. This study investigates whether there was evidence of increasing risk of still-birth with increasing paternal exposure to ionizing radiation received during employment at the Sellafield nuclear installation before the child was conceived. A significant positive association is found between the total paternal preconceptional exposure to external ionizing radiation and the risk of still-birth (after adjustment for year of birth, social class, birth order and paternal age, odds ratio at 100 mSv 1.24 (95% confidence interval 1.04–1.45)). A summary of the principal scientific findings of this study has been published in the Lancet . This paper describes in detail the statistical methods that were used in the investigation and presents the results in full.  相似文献   
93.
Summary.  We detail a general method for measuring agreement between two statistics. An application is two ratios of directly standardized rates which differ only by the choice of the standard. If the statistics have a high value for the coefficient of agreement then the expected squared difference between the statistics is small relative to the variance of the average of the two statistics, and inferences vary little by changing statistics. The estimation of a coefficient of agreement between two statistics is not straightforward because there is only one pair of observed values, each statistic calculated from the data. We introduce estimators of the coefficient of agreement for two statistics and discuss their use, especially as applied to functions of standardized rates.  相似文献   
94.
95.
96.
Spatial variation in soil inorganic nitrogen across an arid urban ecosystem   总被引:4,自引:1,他引:3  
We explored variations in inorganic soil nitrogen (N) concentrations across metropolitan Phoenix, Arizona, and the surrounding desert using a probability-based synoptic survey. Data were examined using spatial statistics on the entire region, as well as for the desert and urban sites separately. Concentrations of both NO3-N and NH4-N were markedly higher and more heterogeneous amongst urban compared to desert soils. Regional variation in soil NO3-N concentration was best explained by latitude, land use history, population density, along with percent cover of impervious surfaces and lawn, whereas soil NH4-N concentrations were related to only latitude and population density. Within the urban area, patterns in both soil NO3-N and NH4-N were best predicted by elevation, population density and type of irrigation in the surrounding neighborhood. Spatial autocorrelation of soil NO3-N concentrations explained 49% of variation among desert sites but was absent between urban sites. We suggest that inorganic soil N concentrations are controlled by a number of ‘local’ or ‘neighborhood’ human-related drivers in the city, rather than factors related to an urban-rural gradient.  相似文献   
97.
This study draws on social identity theory, while developing and testing the Social Identification Model of Prosocial Behavior among voluntary participants in nonprofit organizations. This model posits relationships between organization identification, commitment, satisfaction, and prosocial behavior among nonprofit volunteers. Path analysis results indicate successful identification of the model. Specifically, when volunteers identified with their nonprofit, they had higher levels of prosocial behaviors, commitment, and satisfaction. This study provides several important extensions to social identity theory and nonprofit literatures while highlighting the need for further research examining motivations behind prosocial behaviors within nonprofits.  相似文献   
98.
Many recent papers have used semiparametric methods, especially the log-periodogram regression, to detect and estimate long memory in the volatility of asset returns. In these papers, the volatility is proxied by measures such as squared, log-squared, and absolute returns. While the evidence for the existence of long memory is strong using any of these measures, the actual long memory parameter estimates can be sensitive to which measure is used. In Monte-Carlo simulations, I find that if the data is conditionally leptokurtic, the log-periodogram regression estimator using squared returns has a large downward bias, which is avoided by using other volatility measures. In United States stock return data, I find that squared returns give much lower estimates of the long memory parameter than the alternative volatility measures, which is consistent with the simulation results. I conclude that researchers should avoid using the squared returns in the semiparametric estimation of long memory volatility dependencies.  相似文献   
99.
“以德治国”的德,首指官德.从古至今,官德建设一直受到重视.新形势下,我们应谊借鉴古代官德建设的经验,正视现存的官德问题,加强官德建设.  相似文献   
100.
考虑用 4个长为 2 n - 2 的Bent序列或线性序列级联构造Bent序列的问题 ,给出了第二类线性基Bent序列的类型以及级联序列为第二类Bent基Bent序列的一个充分条件 .  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