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   12924篇
  免费   144篇
管理学   1686篇
民族学   52篇
人才学   1篇
人口学   1098篇
丛书文集   78篇
教育普及   2篇
理论方法论   1174篇
综合类   337篇
社会学   6377篇
统计学   2263篇
  2023年   68篇
  2021年   69篇
  2020年   212篇
  2019年   252篇
  2018年   249篇
  2017年   366篇
  2016年   293篇
  2015年   229篇
  2014年   253篇
  2013年   2051篇
  2012年   394篇
  2011年   318篇
  2010年   211篇
  2009年   234篇
  2008年   262篇
  2007年   279篇
  2006年   216篇
  2005年   351篇
  2004年   296篇
  2003年   257篇
  2002年   268篇
  2001年   314篇
  2000年   297篇
  1999年   309篇
  1998年   210篇
  1997年   204篇
  1996年   215篇
  1995年   188篇
  1994年   204篇
  1993年   177篇
  1992年   236篇
  1991年   232篇
  1990年   211篇
  1989年   219篇
  1988年   194篇
  1987年   185篇
  1986年   189篇
  1985年   174篇
  1984年   207篇
  1983年   200篇
  1982年   165篇
  1981年   138篇
  1980年   140篇
  1979年   167篇
  1978年   136篇
  1977年   120篇
  1976年   102篇
  1975年   101篇
  1974年   95篇
  1973年   93篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
The primary purpose of the present experiment was to examine the effects on the empirical derivation of executive's utility functions caused by the use of random device analogues. The results indicate that utility functions obtained using a random device analogue imply more risk aversion than when these functions are determined by simulating actual decision situations. Furthermore, there is also evidence that the bias is directly related to the monetary amounts involved.  相似文献   
42.
社会人口流动和城市化在中国和全球范围内不断地加强,这些都为中国大多数的农村青年提供了机遇.同时,大量的人口仍然留守农村,无论流动人口输出地有多么偏僻,它们仍继续与日新月异的城市密不可分.正因为如此,农村居民对城市和国家的发展与未来发挥着同等重要的内在作用.  相似文献   
43.
Historically, U.S. regulators have derived cancer slope factors by using applied dose and tumor response data from a single key bioassay or by averaging the cancer slope factors of several key bioassays. Recent changes in U.S. Environmental Protection Agency (EPA) guidelines for cancer risk assessment have acknowledged the value of better use of mechanistic data and better dose–response characterization. However, agency guidelines may benefit from additional considerations presented in this paper. An exploratory study was conducted by using rat brain tumor data for acrylonitrile (AN) to investigate the use of physiologically based pharmacokinetic (PBPK) modeling along with pooling of dose–response data across routes of exposure as a means for improving carcinogen risk assessment methods. In this study, two contrasting assessments were conducted for AN-induced brain tumors in the rat on the basis of (1) the EPA's approach, the dose–response relationship was characterized by using administered dose/concentration for each of the key studies assessed individually; and (2) an analysis of the pooled data, the dose–response relationship was characterized by using PBPK-derived internal dose measures for a combined database of ten bioassays. The cancer potencies predicted for AN by the contrasting assessments are remarkably different (i.e., risk-specific doses differ by as much as two to four orders of magnitude), with the pooled data assessments yielding lower values. This result suggests that current carcinogen risk assessment practices overestimate AN cancer potency. This methodology should be equally applicable to other data-rich chemicals in identifying (1) a useful dose measure, (2) an appropriate dose–response model, (3) an acceptable point of departure, and (4) an appropriate method of extrapolation from the range of observation to the range of prediction when a chemical's mode of action remains uncertain.  相似文献   
44.
The purpose of this paper is firstly to investigate the distribution of two parent low income families in England and Wales and Scotland for see to what extent they differ, and secondly to examine the relative importance of certain contributing factors in determining the distributions. From an analysis of Family Expenditure Survey data it is found that although it is difficult to arrive at statistically verifiable conclusions about the nature of the distributions, interesting qualitative observations can be made.  相似文献   
45.
Social interaction, particularly in older adolescents, increasingly involves computer‐mediated communication. Although studies of public computer‐mediated communication are increasingly common, studies of private text messaging remain rare. As approaches for obtaining such data evolve with technological advances, developmental scientists need designs in which to use such approaches that reduce sampling biases in both participants and text messages. In this study (n = 854; 46% male; 22% African American, 60% European American), we examined selection biases in the participant sample (i.e., factors associated with actual participation), procedural biases in the participant sample (i.e., factors related to failed data capture due to technological or procedural issues), and selection biases in the sample of text messages (i.e., based on self‐reported reasons for texting). Findings from our study suggest that studying human interaction directly through analysis of text message data is not only feasible, but also may be successfully undertaken with minimal biases regarding sample selection and text message selection among those who are engaged in research and engaged in text messaging outside of the study context. However, biases may occur depending on the type of platform (iPhone vs. Android) used by participants for texting.  相似文献   
46.
The study examines the determinants of social expenditure in Sri Lanka for the period 1970–2010. The data are from a new data set assembled by the authors. The social spending data are collected from the Central Bank of Sri Lanka on education, health, and also on welfare spending. The study explains the determinants of social spending considering the demand‐side and the supply‐side driving forces and finds that inequality issues have been a major concern of social policy in Sri Lanka. Similarly, this study implies the influence of political behavior to satisfy voters as explained by the fiscal illusion theory. The globalization is not significant for social expenditure as commonly assumed in developed countries. Even the consequences of the self‐interested behavior of bureaucrats are not evident in the Sri Lankan welfare sector.  相似文献   
47.
Objective. An individual's personal experiences and perception of the collective experience are often linked to political attitudes, especially those concerning the national economy. In this article, we examine whether personal concern about terrorism and perceptions of public concern about terrorism affect attitudes about counterterrorism policies. In addition, we evaluate which factor is the strongest predictor across several counterterrorism policies. Method. We analyze individual‐level survey data collected during the fall of 2001. Results. Our results indicate that perceptions of public concerns are the strongest and most consistent predictor of policy attitudes about terrorism. Conclusion. The implications for theory about perceptions of public opinion and the competing role of personal interest and sociotropic concern are discussed.  相似文献   
48.
49.
The transfer of advantage and disadvantage across multiple generations is receiving increasing attention in the international literature; however, transfers of resources across multiple generations in Australian families are less well understood. Using a longitudinal dataset of Australian children, we have the opportunity to not only investigate the transfer of educational resources across three generations in Australia, but also investigate the gendered nature of these transfers, which has been a limitation of other studies. We find no evidence of individual grandparent education effects on numeracy and reading scores for grandchildren in Year 3, independent of parent educational attainment and other covariates. However, significant effects on numeracy and reading scores were observed for children in families where both the grandmother and grandfather in maternal and paternal grandparent sets had high educational attainment (a diploma or university qualification), and where either or both the mother and father had a university qualification. These results suggest that the contribution of grandparents to the academic achievement of grandchildren cannot be fully explained by the parent generation and that the concentration of human capital in families contributes to educational inequalities across multiple generations that can be observed by eight years of age.  相似文献   
50.
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