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   975篇
  免费   33篇
管理学   72篇
民族学   35篇
人口学   78篇
丛书文集   5篇
理论方法论   90篇
综合类   17篇
社会学   646篇
统计学   65篇
  2021年   5篇
  2020年   23篇
  2019年   33篇
  2018年   32篇
  2017年   32篇
  2016年   32篇
  2015年   20篇
  2014年   21篇
  2013年   211篇
  2012年   29篇
  2011年   29篇
  2010年   25篇
  2009年   24篇
  2008年   26篇
  2007年   19篇
  2006年   28篇
  2005年   32篇
  2004年   29篇
  2003年   23篇
  2002年   27篇
  2001年   25篇
  2000年   12篇
  1999年   10篇
  1998年   13篇
  1997年   13篇
  1996年   11篇
  1995年   12篇
  1994年   17篇
  1993年   8篇
  1992年   17篇
  1991年   9篇
  1990年   9篇
  1989年   8篇
  1988年   13篇
  1987年   9篇
  1986年   10篇
  1985年   7篇
  1984年   9篇
  1983年   11篇
  1982年   9篇
  1981年   5篇
  1979年   6篇
  1978年   9篇
  1977年   8篇
  1976年   6篇
  1975年   4篇
  1974年   5篇
  1973年   9篇
  1966年   3篇
  1965年   3篇
排序方式: 共有1008条查询结果,搜索用时 93 毫秒
61.
62.
The distribution of ant colonies within a community is often well defined, yet this distribution can change due to changing environmental conditions, resource availability, and colony growth. In this study, structure infesting ant communities were sampled for one year within three Puerto Rican housing developments of different ages. These developments represented environments in different stages of recovery after a disturbance (secondary succession). Spatial mapping was used to plot the distribution and abundance of ant communities within these developments. At the beginning of the study, the youngest housing development (1 year since construction), had the fewest number of species present (ave. 1.6 per house). The second housing development (4 years old) had a greater number of species (ave. 2.6 per house), and a greater sampling frequency (the same species collected at multiple houses) than Site 1. The oldest development (8 years old) had both the greatest number of species (ave. 2.7 per house), and sampling frequency of the three sites. In all developments, the number of species, sampling frequency, and ant biomass increased throughout the year as colonies grew and foraging ranges expanded. It was observed in all developments, that species coexistence also increased throughout the year. As colony populations increased, there was a greater occurrence of multiple species being collected at the same sample house. In the youngest development, the two most dominant species increased in numbers during the year and began to be collected from the same sample houses. Spatial diagrams documented that multiple species in the older housing developments (later stages of succession), also shared a common distribution. Even the most dominant species (S. invicta) in all three sites, did not exclude additional species from foraging within its established range.  相似文献   
63.
This paper attempts to show that a philosophical redefinition of the locus of social problems demands a fundamental change in micro-level intervention. A framework and model are introduced that describe a reconceptualization of social work practice rooted in the social-welfare-through-social-change philosophy. Four types of worker activity provide the framework for micro- and macro-level specialization. A micro-level intervention model is then defined in terms of four practice principles: (1) accountability to the client, (2) following the demands of the client task, (3) maximizing environmental supports, and (4) proceeding from an assumption of least content.  相似文献   
64.
65.
This paper examines the impact of immigrant status on home ownership in Australia. It shows that the rate of home ownership for most groups of immigrants is comparable to that of the Australian born. As expected, recently arrived immigrants have relatively low probabilities of owning their own home. These results hold for both analyses pooled across movers and non‐movers, and for analyses restricted to those, both immigrants and the native born, who moved residence in the previous five years. A decomposition of the estimated coefficients of the model of tenure choice is developed. This is shown to enhance understanding of variations in rates of home ownership across birthplace groups.  相似文献   
66.
In the last 15 years, a substantial number of studies have tested the theoretical validity of Bowen family systems theory. A review of this basic research provided empirical support for the relationship between differentiation and chronic anxiety, marital satisfaction, and psychological distress. Bowen's assumption that couples with the same level of differentiation marry was not supported. His specific theories of sibling position and triangulation also received little empirical support. Research on multigenerational transmission has generally ignored Bowen's theoretical perspective, and more research needs to test Bowen's claim that his theory is universal. In addition, researchers still need to examine the effect of differentiation on child functioning, physical health problems, and adaptability.  相似文献   
67.
Body mechanic checklist scores during a one-person pivot transfer, and boosting up in bed were evaluated to determine the effectiveness of training on the work performance of female student nurses from a local college. Thirty subjects participated in the study and were divided into a control group, an experimental group that received basic body mechanic training, and an experimental group that received job specific training. A one-way ANCOVA was calculated to examine the effects of the experimental procedures on the subjects' performance. This revealed a statistically significant difference between the groups (patient transfer F = 10.11, p value < 0.001; boosting F = 38.62, p value < 0.001). A post hoc analysis (Bonferroni procedure) indicated that the job specific training group (mean 11.65, SD 0.66) demonstrated a statistically significant improvement in their performance compared to the other two groups (control group mean 7.5, SD 0.67; BBMT mean 9.66, SD 0.67).  相似文献   
68.
The diffusion of collective violence   总被引:1,自引:0,他引:1  
  相似文献   
69.
Though often conflated, informal physical exercise and organized athletic participation have very different implications for adolescent sexual risk outcomes. The purpose of this research is to disaggregate strenuous exercise from sports, examine how each is associated with sexual risk, and explain the observed differences using the conceptual lens of cultural resource theory. Using a nationally representative sample of over 16,000 public and private high school students, we employ logistic regression to test hypotheses about the gender-specific and race-specific effects of strenuous exercise and athletic participation on adolescent sexual risk behavior. The results show that both forms of physical activity buffer sexual risk for girls. Strenuous exercise is associated with increased odds of sexual risk for boys. Sports and race interact to influence boys' sexual risk outcomes: Athletic participation is associated with lowered odds of sexual risk for white male adolescents, but heightened odds of sexual risk for black male adolescents.  相似文献   
70.
Family influences on adolescent sexual and contraceptive behavior   总被引:4,自引:0,他引:4  
Studies of adolescent pregnancy risk are relevant to understanding responsible adolescent sexual behavior because most investigators have focused on the key proximal determinants of pregnancy--sexual intercourse and contraceptive use--rather than analyzing pregnancy status per se. Lesser pregnancy risk is associated with teens remaining sexually abstinent, postponing onset of intercourse, and having intercourse less often or with fewer partners, as well as by using contraception at first or most recent intercourse and by using contraception consistently over time. Living with a single parent, in a lower SES family, having older sexually active siblings or pregnant/parenting teenage sisters, being a victim of sexual abuse, and residing in disorganized/dangerous neighborhoods all place teens at elevated risk of adolescent pregnancy. Parent-child closeness or connectedness, and parental supervision or regulation of children, in combination with parents values against teen intercourse (or unprotected intercourse), decrease the risk of adolescent pregnancy. Studies about parent-child sexual communication and adolescent pregnancy risk are less conclusive, largely because of methodological complexities.  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