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   17356篇
  免费   290篇
管理学   2229篇
民族学   68篇
人才学   8篇
人口学   1485篇
丛书文集   81篇
教育普及   3篇
理论方法论   1590篇
综合类   174篇
社会学   8754篇
统计学   3254篇
  2023年   91篇
  2021年   101篇
  2020年   221篇
  2019年   330篇
  2018年   358篇
  2017年   533篇
  2016年   374篇
  2015年   283篇
  2014年   369篇
  2013年   3317篇
  2012年   499篇
  2011年   471篇
  2010年   345篇
  2009年   323篇
  2008年   353篇
  2007年   369篇
  2006年   383篇
  2005年   362篇
  2004年   315篇
  2003年   266篇
  2002年   320篇
  2001年   418篇
  2000年   364篇
  1999年   399篇
  1998年   274篇
  1997年   260篇
  1996年   285篇
  1995年   289篇
  1994年   309篇
  1993年   312篇
  1992年   313篇
  1991年   295篇
  1990年   324篇
  1989年   281篇
  1988年   289篇
  1987年   258篇
  1986年   237篇
  1985年   258篇
  1984年   240篇
  1983年   196篇
  1982年   191篇
  1981年   168篇
  1980年   170篇
  1979年   189篇
  1978年   160篇
  1977年   143篇
  1976年   141篇
  1975年   152篇
  1974年   96篇
  1973年   94篇
排序方式: 共有10000条查询结果,搜索用时 109 毫秒
81.
Using cluster analysis, 789 predominately Latino and African American high school youth were classified into varying academic at‐risk profiles using self‐reported levels of academic confidence, motivation to attend school, perceived family support, connections with teachers and peers, and exposure to violence. Six clusters emerged, 5 of which were identified as “at‐risk.” The clusters were examined in relation to academic stress, health status, grades, and school retention. Exposure to violence was one distinguishing feature of youth identified as most vulnerable, vulnerable, and resilient; however, youth identified as resilient recorded better academic outcomes.  相似文献   
82.
83.
This article reports the results of a study that examined the ways in which current and recent TANF recipients assembled or “packaged” their child care arrangements among formal and informal providers. The findings are drawn from in-person, in-depth interviews with current and former welfare recipients. The study found that most of the respondents used multiple providers within the category of informal child care for reasons including availability, the use of a network of social acquaintances as a problem-solving resource, the need to accommodate irregular work hours, and personal trauma that contributed to a distrust of strangers in formal settings. The findings can affect the efficacy of practice with TANF recipients by contributing to social workers’ understanding of the context of decision-making regarding child care.  相似文献   
84.
85.
86.
The probability of illness caused by very low doses of pathogens cannot generally be tested due to the numbers of subjects that would be needed, though such assessments of illness dose response are needed to evaluate drinking water standards. A predictive Bayesian dose-response assessment method was proposed previously to assess the unconditional probability of illness from available information and avoid the inconsistencies of confidence-based approaches. However, the method uses knowledge of the conditional dose-response form, and this form is not well established for the illness endpoint. A conditional parametric dose-response function for gastroenteric illness is proposed here based on simple numerical models of self-organized host-pathogen systems and probabilistic arguments. In the models, illnesses terminate when the host evolves by processes of natural selection to a self-organized critical value of wellness. A generalized beta-Poisson illness dose-response form emerges for the population as a whole. Use of this form is demonstrated in a predictive Bayesian dose-response assessment for cryptosporidiosis. Results suggest that a maximum allowable dose of 5.0 x 10(-7) oocysts/exposure (e.g., 2.5 x 10(-7) oocysts/L water) would correspond with the original goals of the U.S. Environmental Protection Agency Surface Water Treatment Rule, considering only primary illnesses resulting from Poisson-distributed pathogen counts. This estimate should be revised to account for non-Poisson distributions of Cryptosporidium parvum in drinking water and total response, considering secondary illness propagation in the population.  相似文献   
87.
Summary. Possible health hazards from mobile phones arise from the use of the phones themselves and via the base stations that relay signals. Except for an increase in traffic accidents induced by the use of mobile phones in cars the evidence for a health hazard is at most indirect, but it cannot be entirely dismissed; the phones have not been widely used for sufficiently long for direct epidemiological studies to have high sensitivity for detecting any induced incidence of cancer, for example. The background and evidence are briefly reviewed and the steps taken in the UK to make information widely available described.  相似文献   
88.
The Alchian and Allen theorem predicts that it will be harder to find "good" apples in the State of Washington, a prime apple-growing region, than in, say, New York City, where the addition of shipping charges makes "bad" apples comparatively more expensive. We recast the theorem as a testable proposition by explicitly taking the supply side into account and identifying plausible scenarios in which a fixed cost either has no effect on the relative prices of high and low quality grades of the same good in distant markets or, indeed, causes more of the bad apples to be shipped out.  相似文献   
89.
Nonprofit organizations rely on the mission to attract resources and guide decision making. Increasingly, mission statements are recognized as a strong management tool that can motivate employees and keep them focused on the organization's purpose. This research investigated employee attitudes toward the mission in a youth and recreation service organization. In general, the employees expressed positive attitudes toward the organization's mission, and those attitudes were related to employee satisfaction and intentions to remain with the organization. However, dissatisfaction with pay tended to override employee's mission attachment as explanation of why they may leave the organization. The implication is that mission might be salient in attracting employees but less effective in retaining them.  相似文献   
90.
This study reports on New Zealand dairy farmers’ access to and use of information as mediated through conditions of risk and trust within the context of their interpersonal social networks. We located participants’ reports of their information use within their perceived environments of trust and risk, following Giddens's [1990. The consequences of modernity. Polity Press, Stanford, CA] typology of trust and risk in pre-modernity and modernity. The research participants were constant users of interpersonal and print information from numerous sources, and monitored their incoming data in the light of strategic needs, reflecting their roles as both farming practitioners and business owners. Socio-spatial knowledge networks (SSKNs) combine individuals’ explanatory cognitive models of information acquisition and use with a micro-geographical analysis of their interpersonal networks. The participants showed characteristics of pre-modern, modern and even post-modern society in respect of their use of complex interactional forms, as well as a blending of individualistic and communitarian practices and concerns in their professional and personal lives.  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