全文获取类型
收费全文 | 20346篇 |
免费 | 544篇 |
国内免费 | 15篇 |
专业分类
管理学 | 2696篇 |
民族学 | 107篇 |
人才学 | 1篇 |
人口学 | 1847篇 |
丛书文集 | 169篇 |
理论方法论 | 1769篇 |
综合类 | 782篇 |
社会学 | 9989篇 |
统计学 | 3545篇 |
出版年
2023年 | 103篇 |
2021年 | 144篇 |
2020年 | 316篇 |
2019年 | 397篇 |
2018年 | 531篇 |
2017年 | 730篇 |
2016年 | 500篇 |
2015年 | 380篇 |
2014年 | 483篇 |
2013年 | 3282篇 |
2012年 | 706篇 |
2011年 | 692篇 |
2010年 | 557篇 |
2009年 | 488篇 |
2008年 | 528篇 |
2007年 | 579篇 |
2006年 | 562篇 |
2005年 | 505篇 |
2004年 | 419篇 |
2003年 | 384篇 |
2002年 | 404篇 |
2001年 | 520篇 |
2000年 | 455篇 |
1999年 | 425篇 |
1998年 | 314篇 |
1997年 | 288篇 |
1996年 | 275篇 |
1995年 | 271篇 |
1994年 | 260篇 |
1993年 | 249篇 |
1992年 | 313篇 |
1991年 | 291篇 |
1990年 | 288篇 |
1989年 | 260篇 |
1988年 | 250篇 |
1987年 | 271篇 |
1986年 | 229篇 |
1985年 | 255篇 |
1984年 | 276篇 |
1983年 | 263篇 |
1982年 | 237篇 |
1981年 | 208篇 |
1980年 | 190篇 |
1979年 | 211篇 |
1978年 | 179篇 |
1977年 | 153篇 |
1976年 | 152篇 |
1975年 | 173篇 |
1974年 | 137篇 |
1973年 | 110篇 |
排序方式: 共有10000条查询结果,搜索用时 609 毫秒
821.
Edgar G. Karapetyan Anna A. Atoyan Marta E. Sandoyan Demeh Daradkah 《Transition Studies Review》2009,16(2):287-298
During the modern phase of economic reforms directed at the establishment of market economy, many countries with transition
economies face the challenge of solving the issue of formation and rational usage of internal sources of financing the real
sector of the economy, as well as attracting considerable volume of direct foreign investment. In general, financial market
imperfections hold back innovation and growth, and that public policy can complement financial markets. Therefore, the most
relevant issue at the present time is the formation of attendant and complex supervision institutions, as well as an exigency
of innovative economy governance as mainframe principles for further banking system elaboration and financial sector development
in general. We have taken Armenia as a case study for transition economy as far as Armenia is currently in the stage of capital
market development through integration into international financial markets.
相似文献
822.
Catalina Amuedo-Dorantes Susan L. Averett Cynthia A. Bansak 《Journal of population economics》2016,29(3):757-779
Immigration policy is at the forefront of US policy discussions, and the use of welfare benefits by immigrants has been hotly debated. In 1996, Congress enacted welfare reform legislation, which imposed strict restrictions on welfare eligibility for noncitizens. However, a number of states restored access to welfare benefits to immigrants that had been cut out in the federal welfare reform law. Using data from the Current Population Survey, we examine whether immigrant women adjusted their childbearing in response to changes in the generosity of welfare benefits at the state-level. We find that noncitizen women reduced their fertility in response to cutbacks imposed by the legislation. Our findings, which prove robust to a number of identification and robustness checks, underscore how immigrants respond to state-level policies and provide insight into the potential impacts of comprehensive immigration reform, particularly the components related to the path to citizenship and access to public benefits. 相似文献
823.
Susan L. Brown Wendy D. Manning Krista K. Payne 《Population research and policy review》2016,35(1):1-21
Research on family structure and child well-being rarely includes children in same-sex parent families, a notable omission since 28 % of female–female couple households contain children. Using the 2010–2013 pooled current population survey (CPS), we examined children’s economic well-being by family structure. These data were ideal for this study because they included a sizeable number of children in same-sex cohabiting mother families and the CPS measured both official and supplemental poverty, incorporating the cohabiting partner. Using the official poverty measure, children in same-sex cohabiting mother families were more likely to be poor than their counterparts in either different-sex cohabiting or married parent families. Using the supplemental poverty measure, children in same-sex mother families were no more likely to be poor than children in all other types of different-sex two-parent families. 相似文献
824.
Growing human populations make it imperative for ecologists to identify strategies to conserve biodiversity in human-dominated landscapes, such as cities. Effects of urbanization on birds are particularly well-studied, but questions remain regarding the best conservation approaches. Debate about the relative utility of focusing conservation efforts on nature reserves versus developed lands has focused largely on comparing species abundance or presence, with few studies addressing underlying behavioral or demographic mechanisms. Here we evaluated differences in avian reproductive success in nature reserves and matrix habitats to test the assumption that nest predation is lower within areas protected from development. Specifically, we investigated 1) whether nest survival differed in replicated pairs of forest parks and residential neighborhoods and 2) whether differences in nest survival were associated with changes in which species most frequently depredated nests. From April–August 2007–2014, we monitored nests of two native birds, American robin (Turdus migratorius) and northern cardinal (Cardinalis cardinalis), and video-documented nest predators in paired forest-matrix habitats in the Columbus, Ohio metropolitan area. We found similar rates of nest survival in the two habitats for both robins (Χ21?=?0.715, p?=?0.398, n?=?741 nests) and cardinals (Χ21?=?0.926, p?=?0.336, n?=?1156 nests), but interactions between predators and prey differed. In particular, domestic cats (Felis catus) were over five times as likely to depredate cardinal nests in matrix habitats versus forest parks (Χ21?=?7.24, simulated p?=?0.010; nforest?=?3, nmatrix?=?7). Our results suggest that at least in some circumstances, nest success of native birds may be equivalent between nature reserves and adjacent residential matrix habitats, and thus residential neighborhoods may contribute positively to bird conservation in urban landscapes. 相似文献
825.
Landscape urbanization threatens plant phylogenetic diversity in the Brazilian Atlantic Forest 总被引:1,自引:0,他引:1
Valdecir Silva-Junior Danielle G. Souza Rubens T. Queiroz Luiz G. R. Souza Elâine M. S. Ribeiro Bráulio A. Santos 《Urban Ecosystems》2018,21(4):625-634
Urbanization causes species loss around the world, but its effects on phylogenetic diversity are poorly known in tropical forests. Using a patch-landscape approach in an urbanizing region of the Brazilian Atlantic Forest, we tested whether the increase in landscape urbanization reduces plant species density, phylogenetic richness and divergence, and increases the relatedness among co-occurring individuals and species. We assessed plant responses to urbanization in adult (diameter at breast height?>?10 cm) and sapling communities (2.5–10 cm diameter) separately, as saplings are proxies of the future flora. We sampled 2860 woody plants belonging to 155 species in nine circular landscapes with urbanization level varying from 0% to 45%, and estimated the relatedness among the species that have increased and decreased in relative abundance in more urbanized landscapes (winner and losers, respectively). As expected, species density and phylogenetic richness decreased with the increase in urbanization. These responses were consistent for adult and sapling communities, suggesting a persistent loss of species and lineages in more urbanized landscapes. Contrary to our expectations, phylogenetic divergence and structure did not respond to urbanization, indicating that the more urbanized landscapes still retain much evolutionary history. However, because the relatedness among winners was greater than among losers, it is likely that the phylogenetic divergence gradually reduces and the relatedness increases, resulting in impoverished forests with uncertain ability to provide ecosystem services such as carbon storage and pest control. This environmental cost should be taken into account to align urban sprawl with biodiversity conservation. 相似文献
826.
Anna L. Hotton Lance Keene Dennis E. Corbin John Schneider Dexter R. Voisin 《Journal of gay & lesbian social services》2018,30(1):64-81
Black gay men must navigate identities and stigmas related to being gay and Black, and report higher HIV incidence relative to their White male counterparts although they report lower rates of drug use and risky sexual behaviors. This study examined whether closeness to the gay or Black community correlated with HIV-related risk and protective behaviors. Data were drawn from uConnect, a population-based cohort study of young Black men who have sex with men (YBMSM) on Chicago's South Side. The sample consists of 618 Black MSM ranging in age from 16 to 29. Cross-sectional measures for this study include Black and gay community closeness, drug use, sexual risk behaviors, HIV testing, and health promotion behaviors. Closeness with the gay community was associated with greater pre-exposure prophylaxis (PrEP) knowledge as well as participating in health promotion programs along with higher rates of transactional sex and having sex under the influence of substances, and increased odds of self-reported HIV seropositivity. Involvement in the Black community was associated with lower odds of reporting being HIV positive. Findings suggest that programs and initiatives are needed to help promote the positive aspects of the Black and gay communities, while minimizing the negative correlates of such involvements. 相似文献
827.
The purpose of the current study was to examine the relationships among discrimination, mental health, and body image in a national sample of transgender adults. Participants (N = 78) identified as transgender, genderqueer, or other gender-non-binary identities and were recruited via a national online survey. Harassment/rejection, work/school, and other discrimination explained 10.4% of the variance in body appreciation, while satisfaction with life, anxiety, self-esteem, and depression explained 60.7%. Within these models, harassment/rejection was inversely associated with body appreciation, while self-esteem and satisfaction with life were positively associated. A series of path models moving from a measurement model to a more parsimonious and excellent-fitting model found that the effect of harassment/rejection on body appreciation was fully mediated by self-esteem and satisfaction with life, resulting in a multiple mediation. 相似文献
828.
Harvey J. Krahn Cher-Ann Chai Shichen Fang Nancy L. Galambos Matthew D. Johnson 《Journal of youth studies》2018,21(7):905-921
The transition from youth to adulthood in western societies has become more prolonged and complex as traditional societal norms have lost influence. Using retrospective data from a cohort of 43-year-old Canadians surveyed in 2010 (n?=?405), we mapped the timing, sequencing, and duration of ‘first stage’ youth-adult transitions (leaving home, finishing formal education, obtaining a full-time job) and ‘second stage’ youth-adult transitions (marriage, parenthood, home ownership). Latent profile analysis identified five distinct transition profiles – norm-setters, quick adults, uncertain adults, adult students, and delayed adults – with different amounts and timing of post-secondary educational investment playing an important profile-shaping role. Although youth-adult transitions have become less standardized and more individualized, especially for first stage transitions, these transitions are still quite structured and continue to be affected by gender and family socioeconomic status. 相似文献
829.
Elena Berdasco‐Muñoz Léo‐Lyuki Nishibayashi Olivier Baud Valérie Biran Thierry Nazzi 《Infancy》2018,23(2):268-287
Infants born preterm have higher risks of developing linguistic deficits. Considering that the ability to segment words from fluent speech is crucial for lexical acquisition, Experiment 1 tested the ability of healthy extremely‐to‐late preterm infants to segment monosyllabic words at 6 months of postnatal age. Results establish basic segmentation skills in these infants. While we failed to find an effect of the degree of prematurity, this issue will need further exploration. Future studies will also have to specify the scope of these early segmentation skills, both in terms of the types of words segmented, the cues used to do so, and in terms of possible differences in performance between subgroups of preterm infants (e.g., based on gestational age or medical risks). Lastly, given that the preterm infants tested had a mean maturational age of 4 months, Experiment 2 explored monosyllabic segmentation in full‐term 4‐month olds. Infants succeeded at the task, providing the earliest developmental evidence of word segmentation in full‐term infants. These findings better specify the early trajectory of segmentation abilities in both full‐term and healthy, low‐risk preterm infants and support the proposal that prematurity might have a differential effect on the early acquisition of various linguistic levels. 相似文献
830.