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   12194篇
  免费   354篇
  国内免费   2篇
管理学   1608篇
民族学   72篇
人才学   3篇
人口学   1134篇
丛书文集   73篇
理论方法论   1294篇
综合类   237篇
社会学   6433篇
统计学   1696篇
  2021年   58篇
  2020年   188篇
  2019年   285篇
  2018年   306篇
  2017年   435篇
  2016年   315篇
  2015年   230篇
  2014年   301篇
  2013年   1997篇
  2012年   405篇
  2011年   408篇
  2010年   315篇
  2009年   298篇
  2008年   310篇
  2007年   346篇
  2006年   330篇
  2005年   318篇
  2004年   302篇
  2003年   231篇
  2002年   271篇
  2001年   311篇
  2000年   278篇
  1999年   238篇
  1998年   193篇
  1997年   175篇
  1996年   173篇
  1995年   159篇
  1994年   175篇
  1993年   163篇
  1992年   170篇
  1991年   161篇
  1990年   164篇
  1989年   159篇
  1988年   140篇
  1987年   158篇
  1986年   125篇
  1985年   158篇
  1984年   171篇
  1983年   150篇
  1982年   129篇
  1981年   92篇
  1980年   118篇
  1979年   119篇
  1978年   105篇
  1977年   89篇
  1976年   90篇
  1975年   102篇
  1974年   96篇
  1973年   71篇
  1972年   62篇
排序方式: 共有10000条查询结果,搜索用时 218 毫秒
291.
292.
Sea levels are rising in many areas around the world, posing risks to coastal communities and infrastructures. Strategies for managing these flood risks present decision challenges that require a combination of geophysical, economic, and infrastructure models. Previous studies have broken important new ground on the considerable tensions between the costs of upgrading infrastructure and the damages that could result from extreme flood events. However, many risk-based adaptation strategies remain silent on certain potentially important uncertainties, as well as the tradeoffs between competing objectives. Here, we implement and improve on a classic decision-analytical model (Van Dantzig 1956) to: (i) capture tradeoffs across conflicting stakeholder objectives, (ii) demonstrate the consequences of structural uncertainties in the sea-level rise and storm surge models, and (iii) identify the parametric uncertainties that most strongly influence each objective using global sensitivity analysis. We find that the flood adaptation model produces potentially myopic solutions when formulated using traditional mean-centric decision theory. Moving from a single-objective problem formulation to one with multiobjective tradeoffs dramatically expands the decision space, and highlights the need for compromise solutions to address stakeholder preferences. We find deep structural uncertainties that have large effects on the model outcome, with the storm surge parameters accounting for the greatest impacts. Global sensitivity analysis effectively identifies important parameter interactions that local methods overlook, and that could have critical implications for flood adaptation strategies.  相似文献   
293.
294.
While Christianity and feminism may seem at odds with one another, both make normative claims about justice and addressing the needs of those on the margins of power. This article explores what feminism contributes to Christian realism. The current revival of Niebuhrian Christian realism highlights how much it still has to offer as a theoretical underpinning for policy and governance. However, Christian realism remains wedded to masculinist abstractions and power structures, such as the balance of power, that are ultimately harmful to those on the margins. Thus, this article uses feminism to argue for a greater acceptance of vulnerability and obligation in Christian realism.  相似文献   
295.
There is mixed evidence in the existing literature on whether children are associated with greater subjective well-being, with the correlation depending on which countries and populations are considered. We here provide a systematic analysis of this question based on three different datasets: two cross-national and one national panel. We show that the association between children and subjective well-being is positive only in developed countries, and for those who become parents after the age of 30 and who have higher income. We also provide evidence of a positive selection into parenthood, whereby happier individuals are more likely to have children.  相似文献   
296.
Due to economic decline and the recent rise in home foreclosure, many U.S. cities are faced with managing large acreages of vacant land. Interest in local food production on this land has the potential to dramatically reshape the composition of greenspace found within urban landscapes. This study examined how the conversion of vacant land to urban gardens and farms influenced arthropod generalist predator populations and their ability to support biocontrol services. We found that the abundance of Coccinellidae and Syrphidae, and the activity density of Carabidae, Formicidae, and Lycosidae were equivalent among vacant lot and urban garden sites. Dolichopodidae abundance and the activity density of Linyphiidae and Opiliones were reduced in urban gardens whereas Anthocoridae abundance and the activity density of Staphylinidae were greater within urban gardens relative to vacant lots. The biocontrol service supplied by generalist predators was measured using sentinel eggs (Helicoverpa zea (Noctuiidae)) and pupae (Sarcophaga bullata (Sarcophagidae) and Musca domestica (Muscidae)). We found no difference in the biocontrol of H. zea eggs or M. domestica pupae among the focal greenspaces. We found no difference in the removal of S. bullata pupae by predators in June 2010, whereas in August 2010 a greater proportion of pupae were removed in urban garden sites relative to vacant lots. Based on these findings, we discuss the potential of the urban landscape to support generalist predators and sustainable urban gardening and farming.  相似文献   
297.
“Cruising” infants can only walk using external support to augment their balance. We examined cruisers' understanding of support for upright locomotion under four conditions: cruising over a wooden handrail at chest height, a large gap in the handrail, a wobbly unstable handrail, and an ill‐positioned low handrail. Infants distinguished among the support properties of the handrails with differential attempts to cruise and handrail‐specific forms of haptic exploration and gait modifications. They consistently attempted the wood handrail, rarely attempted the gap, and occasionally attempted the low and wobbly handrails. On the wood and gap handrails, attempt rates matched the probability of cruising successfully, but on the low and wobbly handrails, attempt rates under‐ and overestimated the probability of success, respectively. Haptic exploration was most frequent and varied on the wobbly handrail, and gait modifications—including previously undocumented “knee cruising”—were most frequent and effective on the low handrail. Results are discussed in terms of developmental changes in the meaning of support.  相似文献   
298.
This article provides an overview of sociological research on three aspects of feminism: feminism as an ideology; feminism as an identity; and feminism as a practice. I summarize the main contributions of sociological research in each of these areas, and highlight the overarching contributions for understanding contemporary feminism. Three contributions are key. First, sociological research highlights the existence multiple varieties of feminism –“feminisms” as opposed to a singular “feminism.” Second, this research reveals that feminist ideologies, identities, and movements are each dynamic – they have changed historically, and continue to change in response to shifting socio‐political, economic, and technological landscapes. Third, sociological research demonstrates that feminism is alive and well, and in many senses thriving, in the contemporary United States. Though some aspects of feminism are more widespread than others, sociological research challenges the notion that feminism, on the whole, has declined. As an ideology, an identity, and a practice, feminism remains strong in the contemporary United States.  相似文献   
299.
300.
There are hundreds of thousands of children in foster care in the United States, nearly a majority of whom are placed with nonrelative foster parents (U.S. Department of Health and Human Services, 2015). Few scholars (e.g., Nelson, 2014) have explored the communicative process through which a sense of family is created and maintained in foster families, despite the potential positive impact that developing a foster family identity may have on foster family functioning. The purpose of the present study was to understand the communicative strategies that foster parents use to create family identity. Data from interviews with 18 current and former foster parents revealed that through their talk inside and outside of the family, foster parents engaged in integrating biological and foster families, ritualizing, explaining, labeling family roles, and reframing. I discuss the importance of these findings for foster families.  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