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   15155篇
  免费   162篇
  国内免费   1篇
管理学   2085篇
民族学   139篇
人口学   2843篇
丛书文集   19篇
理论方法论   945篇
综合类   357篇
社会学   6569篇
统计学   2361篇
  2023年   50篇
  2022年   44篇
  2021年   56篇
  2020年   154篇
  2019年   162篇
  2018年   1851篇
  2017年   1892篇
  2016年   1262篇
  2015年   200篇
  2014年   237篇
  2013年   1017篇
  2012年   621篇
  2011年   1283篇
  2010年   1170篇
  2009年   879篇
  2008年   933篇
  2007年   1095篇
  2006年   106篇
  2005年   312篇
  2004年   317篇
  2003年   266篇
  2002年   151篇
  2001年   83篇
  2000年   78篇
  1999年   61篇
  1998年   43篇
  1997年   48篇
  1996年   65篇
  1995年   40篇
  1994年   50篇
  1993年   39篇
  1992年   53篇
  1991年   54篇
  1990年   41篇
  1989年   41篇
  1988年   58篇
  1987年   23篇
  1986年   31篇
  1985年   42篇
  1984年   32篇
  1983年   40篇
  1982年   27篇
  1981年   23篇
  1980年   23篇
  1979年   25篇
  1978年   42篇
  1977年   22篇
  1976年   27篇
  1975年   26篇
  1974年   16篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Those involved in sustainability debates on developmental pathways concur in the synergistic potential of integrating traditional ecological knowledge (TEK) and Western scientific approaches. Transhumant pastoralism is a livelihood strategy adapted to spatiotemporal environmental variability in many mountainous and arid regions worldwide. This form of livelihood is based on a mobile logic that is increasingly threatened by novel lifestyles promoted from a Western mind-set and by climate change. The aim of this article is to identify and characterize the different perspectives of environmental and social issues in a pastoral region and their association with labor collaboration among extension agents, framed in an institutional action. We tackled the inquiry about viewpoints with Q methodology and related it to regional problems, alternative solutions, and future development pathways for transhumant pastoralism and landscape management in northwest Patagonia. We identified six perspectives and characterized them with their topological position in the social network. Mediating positions registered the highest network centrality of labor collaborations among agents, whereas more dominant perspectives emphasizing TEK or scientific knowledge registered intermediate centrality. There was consensus on the need for sustainable developmental options, but the emphasis on combining knowledge still needs convergent solutions.  相似文献   
992.
The career decision state (CDS) was studied in relation to RIASEC (Realistic, Investigative, Artistic, Social, Enterprising, Conventional) profiles in Self-Directed Search results among college students (86 women, 27 men). Three CDS dimensions measured by the Career State Inventory (CSI; certainty, satisfaction, and clarity) were examined as predictors of RIASEC primary and secondary constructs. Significant, albeit modest, zero-order correlations (p < .05) emerged between clarity and 3 secondary constructs (i.e., consistency, commonness, and coherence). Results of regression analyses indicated that CSI dimensions predicted 1 secondary construct (i.e., commonness).  相似文献   
993.
Urban Ecosystems - Most studies about the impact of urbanization on bird assemblages are from the Northern Hemisphere and most previous research has reported that cities reduced bird species...  相似文献   
994.
995.
The conditional tail expectation (CTE) is an indicator of tail behavior that takes into account both the frequency and magnitude of a tail event. However, the asymptotic normality of its empirical estimator requires that the underlying distribution possess a finite variance; this can be a strong restriction in actuarial and financial applications. A valuable alternative is the median shortfall (MS), although it only gives information about the frequency of a tail event. We construct a class of tail Lp-medians encompassing the MS and CTE. For p in (1,2), a tail Lp-median depends on both the frequency and magnitude of tail events, and its empirical estimator is, within the range of the data, asymptotically normal under a condition weaker than a finite variance. We extrapolate this estimator and another technique to extreme levels using the heavy-tailed framework. The estimators are showcased on a simulation study and on real fire insurance data.  相似文献   
996.
In this article we introduce a nonparametric estimator of the spectral density by smoothing the periodogram using beta kernel density. The estimator is proved to be bounded for short memory data and diverges at the origin for long memory data. The convergence in probability of the relative error and Monte Carlo simulations show that the proposed estimator automatically adapts to the long- and the short-range dependency of the process. A cross-validation procedure is studied in order to select the nuisance parameter of the estimator. Illustrations on historical as well as most recent returns and absolute returns of the S&P500 index show the performance of the beta kernel estimator. The Canadian Journal of Statistics 48: 582–595; 2020 © 2020 Statistical Society of Canada  相似文献   
997.
This paper considers modelling of a non‐stationary bivariate integer‐valued autoregressive process of order 1 (BINAR(1)) where the cross‐dependence between the counting series is formed through the relationship of the current series with the previous‐lagged count series observations while the pair of innovations is independent and marginally Poisson. In addition, this paper proposes a generalised quasi‐likelihood (GQL) estimating equation based on the exact specification of the mean score and the auto‐covariance structure. The proposed approach is also compared with other popular techniques such as conditional maximum likelihood (CML), generalised least squares (GLS) and generalised method of moment (GMM) based on simulated data from the proposed BINAR(1). Moreover, the model is applied to weekly series of day and night road accidents arising in some regions of Mauritius and is compared with other existing BINAR(1) models.  相似文献   
998.
Perceived racial discrimination (PRD) has been implicated in undermining the mental and physical health of racial/ethnic minorities (e.g., Williams et al. in Am J Public Health 93:200–208, 2003; Wong et al. in J Pers 71:1197–1232, 2003). Researchers have begun to explore the indirect role of health behaviors as one factor in helping to explain this relationship. The goal of the present study was to examine the relationship between PRD and a wide range of health behaviors using a prospective, longitudinal design and to explore the role of gender in moderating these relationships. Using data from the Maryland Adolescent Development in Context Study, we examined the relationship between adolescent PRD (accumulated across ages 14–21) and health behaviors (i.e., diet, substance use, exercise) at age 30 in a sample of middle-class black men and women. Using structural equation modeling, results revealed that more cumulative PRD during adolescence was associated with less healthy eating, more substance use (among men), and more exercise (among women) in young adulthood. Implications of these findings for understanding the role of health behaviors in explaining the link between PRD and health outcomes are considered.  相似文献   
999.
Focus groups were conducted to appreciate the voices of Urban American Indians (UAI) who have mixed ancestries residing in Philadelphia, Pennsylvania. Participants (15 women and 10 men, 19–83 years of age) with a variety of Native ancestries coming from different nations (i.e., blackfeet, blackminkwa, Cherokee, Creek, Delaware, Lakota, Powhatan, Seminole, and Shawnee) reported to also have a Non-Native racial/ethnic ancestry such as African/black, Hispanic, and/or Caucasian/white. Specifically, this study provided evidence about (a) the complexity and challenge of being “mixed” UAI (e.g., “living a culture” as opposed to blood quantum in determining a personal identity) (b) the linkage of cultural identities to mental health (c) contributions of cultural activities to identities and mental health (e.g., therapeutic and healing functions of cultural activities), and (d) very limited urban Native-oriented mental health service (e.g., visions for Native American-centered mental health clinic in an urban setting). Building on those UAI’s voices, this paper provides a context for the need of a culturally respectful transformation of urban mental health system by highlighting the clinical significance of cultural identity and mental health promotion for UAI.  相似文献   
1000.
Panel data in the National Longitudinal Survey of Youth (NLSY97) provide an excellent opportunity to examine the relationship between Hispanic immigration, assimilation, and retail theft. This study examines the relationship between length of time Hispanic youth have spent in America, with the probability of stealing from a store. After controlling for traditional predictors of crime that are correlated with adolescence and immigrant status, random effects logistic regression models indicate that immigrants are less likely to steal than non-immigrants. However, calculating the marginal effects of time spent in the United States reveals that their probability increases with assimilation. Supplementary analyses specify that Hispanic youth who enter the United States within their first 5 years of age will have higher odds of engaging in retail theft. Supportive parenting and a structured home environment is a consistent protective factor in the models. Policies targeting pro-family and social identification are likely to benefit immigrant youth as they acculturate to America.  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