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   25597篇
  免费   414篇
管理学   3742篇
民族学   166篇
人才学   2篇
人口学   3888篇
丛书文集   98篇
教育普及   2篇
理论方法论   1952篇
现状及发展   1篇
综合类   466篇
社会学   11749篇
统计学   3945篇
  2023年   94篇
  2021年   86篇
  2020年   223篇
  2019年   304篇
  2018年   1955篇
  2017年   2098篇
  2016年   1413篇
  2015年   292篇
  2014年   353篇
  2013年   2714篇
  2012年   823篇
  2011年   1578篇
  2010年   1365篇
  2009年   1141篇
  2008年   1215篇
  2007年   1358篇
  2006年   391篇
  2005年   612篇
  2004年   612篇
  2003年   531篇
  2002年   445篇
  2001年   367篇
  2000年   385篇
  1999年   351篇
  1998年   246篇
  1997年   236篇
  1996年   282篇
  1995年   225篇
  1994年   193篇
  1993年   206篇
  1992年   223篇
  1991年   196篇
  1990年   207篇
  1989年   238篇
  1988年   203篇
  1987年   175篇
  1986年   202篇
  1985年   221篇
  1984年   220篇
  1983年   196篇
  1982年   153篇
  1981年   147篇
  1980年   137篇
  1979年   179篇
  1978年   129篇
  1977年   115篇
  1976年   125篇
  1975年   118篇
  1974年   103篇
  1973年   90篇
排序方式: 共有10000条查询结果,搜索用时 757 毫秒
861.
862.
Most Pacific Island countries are located in the tropics, where there is an abundance of mosquitoes with the potential to carry debilitating or life-threatening vector-borne diseases. This article examines three Melanesian countries in which malaria is endemic—Papua New Guinea, Solomon Islands and Vanuatu—but the threat posed by the spread of malaria gives the issues a broader significance to the Pacific region. After discussing the spatial distribution and prevalence of malaria in the Pacific, the article examines a number of health interventions through which people have sought to control malaria. Although the disease was nearly eradicated in the Pacific in the 1970s, it is no longer in retreat. The article concludes by examining why there are still grounds for cautious optimism, and the challenges that Pacific Island countries face in reducing the impact of malaria on their populations. There is a need for prompt and concerted action on malaria at the national, regional and international levels if the public health concerns arising from the disease are to be adequately addressed.  相似文献   
863.
Criminologists have long reported the existence of racial disparity in the criminal justice system, but the important question is why. While some argue that observed differences are a consequence of more criminal behavior among minorities, the weight of the evidence indicates that this is but a partial explanation. In this paper, we study data from a sample of juveniles to examine how racial differences in early police contact, and important social environments—family, school, and neighborhoods—affect later contact and arrests, controlling for self-reported delinquency. We find that early (in middle school) contact with police is an important predictor of later (high school) arrests. Also we found that, in addition to being male and living in a low-income family, children who have parents who have a history of arrest, who have experienced school disciplinary actions, who have delinquent peers, and who are in networks with deviant adults are more likely to have problems with law enforcement. These factors help to explain racial differences in police contacts and arrests.  相似文献   
864.
We investigate whether labor mobility can be a distinct source of growth by studying the productivity impact of business visits (BVs), vis-à-vis that of other well-known drivers of productivity enhancement. Our analysis uses an unbalanced panel—covering on average 16 sectors per year in ten countries during the period 1998–2011—which combines unique and novel data on BVs sourced from the US National Business Travel Association with Organization for Economic Cooperation and Development (OECD) data on R&D and capital formation. We find that mobility through BVs is an effective mechanism to improve productivity, being about half that obtained by investing in R&D. This relevant finding invites viewing short-term mobility as a strategic mechanism and prospective policy tool to overcome productivity slowdowns and foster economic growth.  相似文献   
865.
This paper is an assessment of the impact of child support enforcement and welfare policies on nonmarital teenage childbearing and motherhood. We derive four hypotheses about the effects of policies on nonmarital teenage childbearing and motherhood. We propose that teenage motherhood and school enrollment are joint decisions for teenage girls. Based on individual trajectories during ages 12–19, our analysis uses an event history model for nonmarital teenage childbearing and a dynamic model of motherhood that is jointly determined with school enrollment. We find some evidence that child support policies indirectly reduce teen motherhood by increasing the probability of school enrollment, which, in turn, reduces the probability of teen motherhood. This finding suggests that welfare offices may wish to place greater weight on outreach programs that inform more teenagers of the existence of strong child support enforcement measures. Such programs might reduce nonmarital teen motherhood further and thus reduce the need for welfare support and child support enforcement in the long run.
Lingxin HaoEmail:
  相似文献   
866.
Understanding contemporary urban landscapes requires multiple sets of spatially and temporally compatible data that can integrate historical land use patterns and disturbances to land cover. This paper presents three principal methods: (1) core analysis; (2) historic mapping; and (3) gradient analysis, to link spatial and temporal data for urban ecosystems and applies their use in the Baltimore-Chesapeake region. Paleoecological evidence derived from the geochronology of sediment cores provides data on long-term as well as recent changes in vegetative land cover. This information, combined with contemporary vegetation maps, provides a baseline for conducting trend analyses to evaluate urbanization of the landscape. A 200-year historical land use database created from historical maps, census data, and remotely sensed data provides a spatial framework for investigating human impacts on the region. A geographic information system (GIS) integrates core analyses with historic data on land use change to yield a comprehensive land use and land cover framework and rates of change. These data resources establish the regional foundation for investigating the ecological components of an urban ecosystem. Urban-rural gradient analyses and patch analyses are proposed as the most appropriate methods for studying the urban ecosystem as they link ecological and social patterns and processes for varying degrees of urbanization.  相似文献   
867.
Lesbian, gay, bisexual, transgender and queer-identified (LGBTQ) youth are a population with a unique set of service needs. Existing research on effective service methods with LGBTQ youth is limited. Youth empowerment holds potential as an approach that can impact well-being among youth who face discrimination. The current study explores the relationship between the social justice youth development framework (Ginwright and James, New Directions Youth Dev 96:27–46, 2002) and youth empowerment in a sample of LGBTQ youth. Multiple regression analysis of data collected through a community-based youth program identified critical consciousness and community engagement as significant predictors of empowerment. Findings suggest that programs that promote these factors among LGBTQ youth using the social justice youth development framework may enhance empowerment thereby increasing other aspects of well-being.  相似文献   
868.
Two within household telephone sampling techniques for collecting citizen survey data for community mental health center's needs assessments were compared on the basis of respondent demographic characteristics; response, completion, and refusal rates; and, administrative costs. Initially, all households were chosen via random digit dialing. Then, one technique allowed the surveyor to interview any adult member of a household who answered the phone. The other technique used was developed by Troldahl and Carter and required the use of a reference table procedure to determine the appropriate respondent. While more expensive, the Troldahl-Carter method produced significantly better representativeness of the population for a rural county. Factors relating to a decision regarding which technique to employ are discussed.  相似文献   
869.
A large number of functional forms has been suggested in the literature for estimating Lorenz curves that describe the relationship between income and population shares. The traditional way of overcoming functional-form uncertainty when estimating a Lorenz curve is to choose the function that best fits the data in some sense. In this paper we describe an alternative approach for accommodating functional-form uncertainty, namely, how to use Bayesian model averaging to average the alternative functional forms. In this averaging process, the different Lorenz curves are weighted by their posterior probabilities of being correct. Unlike a strategy of picking the best-fitting function, Bayesian model averaging gives posterior standard deviations that reflect the functional-form uncertainty. Building on our earlier work (Chotikapanich and Griffiths, 2002), we construct likelihood functions using the Dirichlet distribution and estimate a number of Lorenz functions for Australian income units. Prior information is formulated in terms of the Gini coefficient and the income shares of the poorest 10% and poorest 90% of the population. Posterior density functions for these quantities are derived for each Lorenz function and are averaged over all the Lorenz functions.  相似文献   
870.
Previous research has examined self-identified sexual orientation in relation to self-reports on the Big Five personality factors. Here we extend this research by including asexuality as a fourth sexual orientation and by assessing the HEXACO personality factors, using self-report data from a large anonymous online sample (N ≈ 100,000). A large overlap was observed among all sexual orientation groups on all six HEXACO dimensions, but notable group differences also emerged. All nonheterosexual groups, particularly bisexual people, averaged higher in openness to experience than did heterosexuals. Heterosexual men averaged much lower in emotionality than heterosexual women, but only a small difference was observed between gay men and lesbians on this dimension. Asexual men and women averaged lower in extraversion and in some facets of emotionality (specifically, dependence and sentimentality) than did the other sexual orientation groups of the same sex. Results are discussed in relation to the different social realities that each sexual orientation group often experiences, along with the (gender-related) developmental influences hypothesized to underlie in part the origins of sexual orientation.  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