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:      
  示例: 沙坡头地区,人工植被区,变化  检索词用空格隔开表示必须包含全部检索词,用“,”隔开表示只需满足任一检索词即可!
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   2938篇
  免费   14篇
管理学   191篇
民族学   85篇
人才学   2篇
人口学   323篇
丛书文集   67篇
教育普及   1篇
理论方法论   437篇
现状及发展   1篇
综合类   142篇
社会学   1585篇
统计学   118篇
  2020年   6篇
  2019年   3篇
  2014年   5篇
  2013年   8篇
  2012年   420篇
  2011年   259篇
  2010年   90篇
  2009年   33篇
  2008年   146篇
  2007年   168篇
  2006年   177篇
  2005年   192篇
  2004年   165篇
  2003年   109篇
  2002年   95篇
  2001年   77篇
  2000年   68篇
  1999年   60篇
  1998年   47篇
  1997年   36篇
  1996年   39篇
  1995年   42篇
  1994年   33篇
  1993年   56篇
  1992年   55篇
  1991年   47篇
  1990年   34篇
  1989年   33篇
  1988年   44篇
  1987年   32篇
  1986年   39篇
  1985年   35篇
  1984年   30篇
  1983年   44篇
  1982年   45篇
  1981年   46篇
  1980年   35篇
  1979年   24篇
  1978年   16篇
  1977年   7篇
  1976年   5篇
  1974年   8篇
  1973年   4篇
  1972年   3篇
  1971年   2篇
  1970年   3篇
  1968年   2篇
  1967年   2篇
  1966年   8篇
  1948年   2篇
排序方式: 共有2952条查询结果,搜索用时 0 毫秒
71.
ObjectiveTo undertake a systematic review of the literature to determine whether Asian ethnicity is an independent risk factor for severe perineal trauma in childbirth.MethodOvid Medline, CINAHL, and Cochrane databases published in English were used to identify appropriate research articles from 2000 to 2010, using relevant terms in a variety of combinations. All articles included in this systematic review were assessed using the Critical Appraisal Skills Programme (CASP) ‘making sense of evidence’ tools.FindingsAsian ethnicity does not appear to be a risk factor for severe perineal trauma for women living in Asia. In contrast, studies conducted in some Western countries have identified Asian ethnicity as a risk factor for severe perineal trauma. It is unknown why (in some situations) Asian women are more vulnerable to this birth complication. The lack of an international standard definition for the term Asian further undermines clarification of this issue. Nevertheless, there is an urgent need to explore why Asian women are reported to be significantly at risk for severe perineal trauma in some Western countries.ConclusionCurrent research on this topic is confusing and conflicting. Further research is urgently required to explore why Asian women are at risk for severe perineal trauma in some birth settings.  相似文献   
72.
Kalil A  Mogstad M  Rege M  Votruba M 《Demography》2011,48(3):1005-1027
This study examines the link between divorced nonresident fathers’ proximity and children’s long-run outcomes, using high-quality data from Norwegian population registers. We follow (from birth to young adulthood) each of 15,992 children born into married households in Norway in the years 1975–1979 whose parents divorced during his or her childhood. We observe the proximity of the child to his or her father in each year following the divorce and link proximity to educational and economic outcomes for the child in young adulthood, controlling for a wide range of observable characteristics of the parents and the child. Our results show that closer proximity to the father following a divorce has, on average, a modest negative association with offspring’s outcomes in young adulthood. The negative associations are stronger among children of highly educated fathers. Complementary Norwegian survey data show that highly educated fathers report more post-divorce conflict with their ex-wives as well as more contact with their children (measured in terms of the number of nights that the child spends at the father’s house). Consequently, the father’s relocation to a more distant location following the divorce may shelter the child from disruptions in the structure of the child’s life as they split time between households and/or from post-divorce interparental conflict.  相似文献   
73.

Background

In February 2009 the Improving Maternity Services in Australia – The Report of the Maternity Services Review (MSR) was released, with the personal stories of women making up 407 of the more than 900 submissions received. A significant proportion (53%) of the women were said to have had personal experience with homebirth. Little information is provided on what was said about homebirth in these submissions and the decision by the MSR not to include homebirth in the funding and insurance reforms being proposed is at odds with the apparent demand for this option of care.

Method

Data for this study comprised 832 submissions to the MSR that are publicly available on the Commonwealth of Australia Department of Health and Aging website. All 832 submissions were downloaded, coded and then entered into NVivo. Content analysis was used to analyse the data that related to homebirth.

Findings

450 of the submissions were from consumers of maternity services (54%). Four hundred and seventy (60%) of the submissions mentioned homebirth. Overall there were 715 references to home birth in the submissions. The submissions mentioning homebirth most commonly discussed the ‘Benefits’ and ‘Barriers’ in accessing this option of care. Benefits to the baby, mother and family were described, along with the benefits obtained from having a midwife at the birth, receiving continuity of care and having a good birth experience. Barriers were described as not having access to a midwife, no funding, no insurance and lack of clinical privileging for midwives.

Conclusion

Many positive recommendations have come from the MSR, however the decision to exclude homebirth from these reforms is perplexing considering the large number of submissions describing the benefits of and barriers to homebirth in Australia. A concerning number of submissions discuss having had or having considered an unattended birth at home due to these barriers. Overall there is the belief that not enabling access to funded, insured homebirth in Australia is a violation of human rights. It appears that homebirth was considered by the MSR as ‘too hot to handle’ and by dismissing it as a minority issue the government sought to avoided dealing with homebirth as a ‘sensitive and controversial issue.’  相似文献   
74.
The minority stress model (Meyer, 2003) has been proposed to explain higher rates of psychopathology in lesbian, gay, and bisexual individuals. However, studies of minority stress have rarely taken into account the interface between minority stress and same-sex relationship processes. In the current study, 142 gay men in romantic relationships completed an online survey assessing minority stress constructs, relationship features, and relationship satisfaction. Minority stress was not directly related to relationship satisfaction, while commitment, trust, and support from one's partner were related to relationship satisfaction. Significant moderation effects emerged between discrimination and trust and between internalized heterosexism and commitment, indicating that trust was related to satisfaction for those who had experienced frequent discrimination, while commitment was related to satisfaction for those low in internalized heterosexism.  相似文献   
75.
People's childbearing intentions change over the course of their reproductive lives. These changes have been conceptualized as occurring in response to the realization that an individual is unlikely to achieve his or her intended fertility, because of constraints such as the "biological clock" or lack of a partner. In this article, we find that changes to child-bearing plans are influenced by a much wider range of factors than this. People change their plans in response to the wishes of their partners, in response to social norms, as the result of repartnering, and as the result of learning about the costs and benefits of parenthood; there are also differences between the factors that influence men's and women's decision-making. In a departure from existing studies in this area, we use a flexible analytical framework that enables us to analyze increases in planned fertility separately from decreases. This allows us to uncover several complexities of the decision-making process that would otherwise be hidden, and leads us to conclude that the determinants of increases in planned fertility are not simply equal and opposite to the determinants of decreases.  相似文献   
76.
This article examines how nontraditional representations of gender can complicate received social norms, and it examines, in particular, how pre-adolescent suburban youth reconfigure social codes within popular film in order to identify positive queer aesthetics. While several studies have documented the function of classic and mainstream film in the tradition of queer reading, there has been comparatively less analysis devoted to the ways that filmic representations themselves might contribute to theoretical debates regarding sexual identity. As a case in point, this essay analyzes the 1978 musical Grease in order to suggest ways that critics might navigate between strict social constructionist and essentialist theories of sexual identity in order to identify avenues for queer identification within non-queer contexts.  相似文献   
77.
Evaluation of the mortality impact of nationwide disease-prevention efforts is complicated by potential endogeneity: programme recipients may have unobserved characteristics that simultaneously make them both more likely to become recipients and more likely to survive as a result of other health practices. This population-based study assesses the mortality impact of a nationwide programme that distributed insecticide-treated nets (ITNs) to mothers of children aged 9-59 months in Togo. By comparing mortality rates before and after the programme according to households' eligibility status, we demonstrate that a one-time programme that restricts eligibility to households with a surviving child excludes some households with a high risk of child mortality. We then apply simultaneous estimation models to untangle the mortality impact of ITNs from the effects of unobserved confounders and show that among eligible households, living in a household with ITNs significantly reduces mortality for children aged 20-59 months, even after controlling for endogeneity.  相似文献   
78.
79.
The United Nations publishes estimates of HIV prevalence, AIDS mortality, and orphan numbers for all countries of the world. It is important to assess the validity of these model-based estimates since they underpin much policy concerned with care and prevention. Household surveys that ask questions about the survival of children's parents (orphanhood) offer an independent source of data with which these estimates can be compared. Survey estimates of maternal and paternal orphans are significantly lower than model estimates for 40 surveys in 36 countries of sub-Saharan Africa (p < 0.001, p = 0.002). This is probably because adult mortality from causes other than AIDS is lower than assumed in the models, although under-reporting of orphanhood in surveys may also play a role. Reducing adult mortality from causes other than AIDS brings the model estimates into close agreement with the surveys. This suggests that the fraction of orphans attributable to AIDS is greater than estimated previously.  相似文献   
80.
Prior research on Mexican migration has shown that social networks and economic incentives play an important role in determining migration outcomes. We use experimental data from PROGRESA, Mexico's primary poverty-reduction program, to evaluate the effects of conditional cash transfers on migration both domestically and to the United States. Our study complements a growing body of literature aimed at overcoming longstanding hurdles to the establishment of causal validity in empirical studies of migration. Analysis based on the data collected before and after the program's onset shows that conditional transfers reduce U.S. migration but not domestic migration. The data also enable us to explore the role of existing family and community migration networks. The results show that migration networks strongly influence migration, but that the effect of conditional transfers on migration is apparently not mediated by existing migration network structures. Our results suggest that conditional transfers may be helpful in managing rural out-migration, particularly to the United States.  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