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   7994篇
  免费   205篇
管理学   1075篇
民族学   33篇
人才学   1篇
人口学   732篇
丛书文集   34篇
理论方法论   719篇
综合类   286篇
社会学   3447篇
统计学   1872篇
  2023年   40篇
  2021年   49篇
  2020年   95篇
  2019年   132篇
  2018年   177篇
  2017年   249篇
  2016年   207篇
  2015年   157篇
  2014年   180篇
  2013年   1423篇
  2012年   304篇
  2011年   224篇
  2010年   179篇
  2009年   162篇
  2008年   197篇
  2007年   188篇
  2006年   144篇
  2005年   202篇
  2004年   180篇
  2003年   219篇
  2002年   242篇
  2001年   225篇
  2000年   196篇
  1999年   187篇
  1998年   146篇
  1997年   111篇
  1996年   123篇
  1995年   105篇
  1994年   91篇
  1993年   100篇
  1992年   123篇
  1991年   115篇
  1990年   111篇
  1989年   101篇
  1988年   108篇
  1987年   108篇
  1986年   102篇
  1985年   124篇
  1984年   97篇
  1983年   105篇
  1982年   71篇
  1981年   78篇
  1980年   70篇
  1979年   73篇
  1978年   76篇
  1977年   50篇
  1976年   45篇
  1975年   55篇
  1974年   47篇
  1973年   42篇
排序方式: 共有8199条查询结果,搜索用时 453 毫秒
1.
2.
3.
This paper proposes a new hysteretic vector autoregressive (HVAR) model in which the regime switching may be delayed when the hysteresis variable lies in a hysteresis zone. We integrate an adapted multivariate Student-t distribution from amending the scale mixtures of normal distributions. This HVAR model allows for a higher degree of flexibility in the degrees of freedom for each time series. We use the proposed model to test for a causal relationship between any two target time series. Using posterior odds ratios, we overcome the limitations of the classical approach to multiple testing. Both simulated and real examples herein help illustrate the suggested methods. We apply the proposed HVAR model to investigate the causal relationship between the quarterly growth rates of gross domestic product of United Kingdom and United States. Moreover, we check the pairwise lagged dependence of daily PM2.5 levels in three districts of Taipei.  相似文献   
4.
An accurate procedure is proposed to calculate approximate moments of progressive order statistics in the context of statistical inference for lifetime models. The study analyses the performance of power series expansion to approximate the moments for location and scale distributions with high precision and smaller deviations with respect to the exact values. A comparative analysis between exact and approximate methods is shown using some tables and figures. The different approximations are applied in two situations. First, we consider the problem of computing the large sample variance–covariance matrix of maximum likelihood estimators. We also use the approximations to obtain progressively censored sampling plans for log-normal distributed data. These problems illustrate that the presented procedure is highly useful to compute the moments with precision for numerous censoring patterns and, in many cases, is the only valid method because the exact calculation may not be applicable.  相似文献   
5.
This study investigated the risk factors associated with the occurrence of child physical and psychological abuse in South Korea based on the ecological theory of child maltreatment. A subsample of 3‐ to 18‐year‐old children from “A Study on the Current State of Child Abuse and Neglect,” a nationally representative study on child abuse and neglect, was utilized for secondary data analysis. The sample was divided into two age groups (third graders in elementary school and below and fourth graders and above). We utilized hierarchical logistic regression for each age group separately to analyze the data. The variables at each level of the system (i.e., ontogenic development, microsystem, and exosystem) were entered into the model in sequential order. The results showed the common risk factors for both age groups are the caregiver's experience of abuse in childhood, the child's problem behavior, exposure to domestic violence, community size, and informal social control. The child's age was also significant in both groups but in the opposite direction. Social support was a significant predictor for the younger age group only, while the caregiver's level of education was significant for the older age group only. Implications for future research and practice are discussed based on the study results.  相似文献   
6.
To study the homogeneity and influences on scientists'perspectives of environmental risks, we have examined similarities and differences in risk perceptions, particularly regarding nuclear wastes, and policy preferences among 1011 scientists and engineers. We found significant differences ( p 0.05)in the patterns of beliefs among scientists from different fields of research. In contrast to physicists, chemists, and engineers, life scientists tend to: (a)perceive the greatest risks from nuclear energy and nuclear waste management; (b)perceive higher levels of overall environmental risk; (c)strongly oppose imposing risks on unconsenting individuals; and (d)prefer stronger requirements for environmental management. On some issues related to priorities among public problems and calls for government action, there are significant variations among life scientists or physical scientists. We also found that–independently of field of research–perceptions of risk and its correlates are significantly associated with the type of institution in which the scientist is employed. Scientists in universities or state and local governments tend to see the risks of nuclear energy and wastes as greater than scientists who work as business consultants, for federal organizations, or for private research laboratories. Significant differences also are found in priority given to environmental risks, the perceived proximity of environmental disaster, willingness to impose risks on an unconsenting population, and the necessity of accepting risks and sacrifices.  相似文献   
7.
Epidemiological data show high rates of suicide attempts among adolescent Latinas. Few studies have addressed the psychosocial, cultural and family correlates of suicide attempts among this age group of a rapidly growing population. The authors studied 31 adolescent Hispanic females who were receiving mental health services; 14 girls had attempted suicide in the previous five years and 17 had never attempted suicide. The two groups of girls did not differ significantly with respect to demographic profiles, levels of depression, family type, acculturation, or self-esteem. However, as hypothesized, the mutuality between girls and their mothers was lower among suicide attempters. Maladaptive coping skills of withdrawal and wishful thinking were more commonly used by attempters, and non-attempters used emotional regulation and problem-solving more frequently. Findings are discussed within the context of the empirical and theoretical literature and implications for practice are considered.  相似文献   
8.
Abstract In recent years, church burnings in the South have attracted a great deal of attention. Many commentators have charged that they are a product of strained race relations throughout the South, and particularly of severe racial tensions in Southern rural areas. In this study we evaluate these claims. We begin by mapping the spatial coordinates of recorded church burnings from 1990 to 1997, and find that church arsons indeed are concentrated in the South. Church burnings, however, are a more urban phenomenon than popular media accounts would suggest. Our analysis then explores the influence of contextual factors (population and locale, racial composition and inequality, so‐cioeconomic conditions, local religious ecology, and patterns of reported crime) on church burnings in counties located in the study region. Logistic regression models confirm that church arsons are most likely to occur in small metropolitan statistical areas (MSAs) and non‐MSA counties containing a city of at least 10,000 residents. Church burnings also are especially likely in counties with a higher percentage of black residents, a larger number of churches relative to the rest of the state, and a higher arson rate. We conclude by discussing the implications of these findings for future research and public policy.  相似文献   
9.
Using data from a national survey of pharmacists who are members of the American Pharmaceutical Association, we examine the union voting intentions of employee pharmacists. We find that union instrumentality regarding professionalism is a primary predictor of union voting intent among these employees. In addition, this predictor mediates the relationship between the level of professionalism at a pharmacist’s current employment situation and his or her expected union vote. Also important to union voting intent are respondent beliefs about union instrumentality regarding pecuniary issues, prior union experience, as well as overall job satisfaction. Implications for employers, unions, and researchers are drawn. We thank Mary Graham, Jann Skelton, Paul Swiercz, Terry Thomason, and participants at the Seventh Bar-gaining Group Conference at Michigan State University for their comments on earlier versions of this paper. This research was made possible by a grant from the American Pharmaceutical Association.  相似文献   
10.
运用参与性诊断(即PRRA)方法对临安示范林地区的森林经营主要政策进行了诊断分析,找出了现行政策存在的问题,如:政策环境欠佳,产权政策不到位,税费政策不合理,林业产品生产、加工和销售脱节,森林生态效益补偿政策欠规范、不合理等.同时,运用参与性设计的方法对若干主要政策进行专项设计,并在此基础上,从优化森林可持续经营的政策环境和规范政策系统运行两方面入手,提出一套科学、合理和有效的适合当地水平的森林可持续经营综合设计方案,以促进示范林网络的发展.  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