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   506篇
  免费   20篇
管理学   61篇
民族学   6篇
人口学   38篇
丛书文集   3篇
理论方法论   94篇
综合类   9篇
社会学   263篇
统计学   52篇
  2023年   6篇
  2022年   4篇
  2020年   4篇
  2019年   11篇
  2018年   8篇
  2017年   19篇
  2016年   11篇
  2015年   20篇
  2014年   14篇
  2013年   93篇
  2012年   18篇
  2011年   18篇
  2010年   10篇
  2009年   7篇
  2008年   11篇
  2007年   17篇
  2006年   18篇
  2005年   16篇
  2004年   17篇
  2003年   14篇
  2002年   6篇
  2001年   14篇
  2000年   10篇
  1999年   6篇
  1998年   9篇
  1997年   9篇
  1996年   3篇
  1995年   7篇
  1994年   10篇
  1993年   4篇
  1991年   4篇
  1990年   6篇
  1989年   7篇
  1988年   10篇
  1987年   4篇
  1986年   5篇
  1985年   7篇
  1984年   7篇
  1983年   9篇
  1982年   5篇
  1981年   7篇
  1980年   5篇
  1979年   4篇
  1978年   5篇
  1977年   3篇
  1976年   3篇
  1975年   3篇
  1974年   3篇
  1973年   2篇
  1970年   4篇
排序方式: 共有526条查询结果,搜索用时 31 毫秒
51.
The present study was aimed at assessing the health consequences of the presence of radon in Quebec homes and the possible impact of various screening programs on lung cancer mortality. Lung cancer risk due to this radioactive gas was estimated according to the cancer risk model developed by the Sixth Committee on Biological Effects of Ionizing Radiations. Objective data on residential radon exposure, population mobility, and tobacco use in the study population were integrated into a Monte‐Carlo‐type model. Participation rates to radon screening programs were estimated from published data. According to the model used, approximately 10% of deaths due to lung cancer are attributable to residential radon exposure on a yearly basis in Quebec. In the long term, the promotion of a universal screening program would prevent less than one death/year on a province‐wide scale (0.8 case; IC 99%: –3.6 to 5.2 cases/year), for an overall reduction of 0.19% in radon‐related mortality. Reductions in mortality due to radon by (1) the implementation of a targeted screening program in the region with the highest concentrations, (2) the promotion of screening on a local basis with financial support, or (3) the realization of systematic investigations in primary and secondary schools would increase to 1%, 14%, and 16.4%, respectively, in the each of the populations targeted by these scenarios. Other than the battle against tobacco use, radon screening in public buildings thus currently appears as the most promising screening policy for reducing radon‐related lung cancer.  相似文献   
52.
I point to contradictions in American individualism not unlike those suggested by Robin M. Williams Jr. I go on to suggest how twenty‐first‐century sociologists might better understand this aspect of American exceptionalism: not as an egoistic, asocial individualism, but as a covenantal, social voluntarism.  相似文献   
53.
Assessments of aggregate exposure to pesticides and other surface contamination in residential environments are often driven by assumptions about dermal contacts. Accurately predicting cumulative doses from realistic skin contact scenarios requires characterization of exposure scenarios, skin surface loading and unloading rates, and contaminant movement through the epidermis. In this article we (1) develop and test a finite-difference model of contaminant transport through the epidermis; (2) develop archetypal exposure scenarios based on behavioral data to estimate characteristic loading and unloading rates; and (3) quantify 24-hour accumulation below the epidermis by applying a Monte Carlo simulation of these archetypal exposure scenarios. The numerical model, called Transient Transport through the epiDERMis (TTDERM), allows us to account for variable exposure times and time between exposures, temporal and spatial variations in skin and compound properties, and uncertainty in model parameters. Using TTDERM we investigate the use of a macro-activity parameter (cumulative contact time) for predicting daily (24-hour) integrated uptake of pesticides during complex exposure scenarios. For characteristic child behaviors and hand loading and unloading rates, we find that a power law represents the relationship between cumulative contact time and cumulative mass transport through the skin. With almost no loss of reliability, this simple relationship can be used in place of the more complex micro-activity simulations that require activity data on one- to five-minute intervals. The methods developed in this study can be used to guide dermal exposure model refinements and exposure measurement study design.  相似文献   
54.
55.
Constellation work is a therapeutic and counselling intervention recognised in Germany and other European countries since the 1970s. Various scientists and practitioners have contributed to its theoretical and practical development, and research on the subject has increased over the past few years. However culture in constellation work has received little research attention and has not been empirically studied in African contexts. The aim of this article is to reflect on culture and its influence on constellation work in multicultural, post‐apartheid South Africa. An empirical qualitative research approach within the phenomenological paradigm was adopted. Six constellation facilitators were interviewed with in‐depth and field notes taken during participative observations of constellation workshops. The findings provide insight into culture in constellation work in the South African context. Theoretical and practical recommendations for scientists and therapy practitioners working with systemic interventions like constellation work are provided.  相似文献   
56.
This study aimed to deepen our understanding of the motivational mechanisms involved in the relationship between transformational leadership (TFL) and employee functioning. Drawing on the TFL literature, the job demands–resources model and self-determination theory, we propose an integrative model that relates TFL to employee psychological health (burnout and psychological distress), attitudes (occupational commitment and turnover intention) and performance (professional efficacy, self-reported individual and objective organizational performance) through two explanatory mechanisms: perceived job characteristics (job demands and resources) and employee motivation (autonomous and controlled). This research was conducted in two occupational settings (nurses and school principals), using a distinct variable operationalization for each. Results of both studies provide support for the hypothesized model, suggesting that TFL relates to optimal job functioning (psychological health, job attitudes and performance) by contributing to favourable perceptions of job characteristics (more resources and less demands) and high-quality work motivation (more autonomous motivation and less controlled motivation) in employees. Theoretical contributions and managerial implications as well as directions for future research are presented.  相似文献   
57.
The aim of this study was to provide insight into the differential relationships between job characteristics (job demands and resources) and employee functioning by examining the psychological and motivational processes involved. Drawing on self-determination theory, we tested a model in which job demands are positively related to negative manifestations of employee functioning (psychological distress and psychosomatic complaints) through psychological need frustration and low-quality work motivation (controlled motivation), whereas job resources are positively related to positive manifestations of employee functioning (work engagement and job performance) through need satisfaction and high-quality work motivation (autonomous motivation). Data were collected from 699 Canadian nurses. Structural equation modelling (SEM) results support the proposed model: psychological needs and work motivation partially mediated the relationship between job characteristics and employee functioning. Specifically, job demands negatively predicted employee functioning (high distress and psychosomatic complaints, low engagement and performance) through need frustration and controlled motivation. In contrast, while positively predicting need satisfaction and negatively predicting need frustration, job resources fostered optimal work motivation (more autonomous and less controlled motivation) and employee functioning. The implications for self-determination theory (SDT) and research on occupational health and stress are discussed.  相似文献   
58.
Recent scholarship emphasizes differences among ethnic groups' internal migration patterns. Yet, with few exceptions, research has focused on the Anglo‐American world, neglecting experiences from other regions. This paper is part of a larger research project that studies mobility among the Arab minority in Israel and its driving forces. In this paper we examine patterns of internal migration by analysing the propensity to migrate as well as migrants' individual and social characteristics. First, we survey the theoretical backdrop that is suggested by recent geographic literature on internal migration among ethnic and racial minorities, including native groups. Second, we contextualize the group studied, providing necessary background information on the political, socio‐economic and demographic conditions of Arabs in Israel. We briefly discuss attributes that are – or have been – potential hindering factors to Arab mobility in the Jewish state. Finally, we analyse 1995 national census data at the micro scale and provide a basis for future explanations of the phenomenon. We conclude by outlying some future directions in the study of internal migration of minorities in Israel.  相似文献   
59.
In this paper, we examine individuals’ career migration across international borders. It is widely recognized that globalization has fundamental implications for the careers of people across geographical and cultural boundaries. However, our understanding of the interplay of migration, career development and national/cultural identities remains undeveloped within the extant literature. In this paper, we seek to offer insights into this relationship. Focusing on Indian scientists, an occupational group whose careers have long been associated with movement around the world, in this paper we examine these issues. Empirically, we examine three themes: why Indian scientists see international mobility as important in the development of their careers; continued links with India; and the interplay of national/cultural affiliation and respondents’ career experiences. In light of our findings, in the discussion section we argue that considering Indian scientists as a career diaspora highlights three important features that in the main have received only limited attention in the extant literature: career as a social form and process; the notion of the scientific career as a cultural product; and the interrelationship of career and national/cultural affiliation as ongoing facets of individuals’ identities as they develop diasporic careers.  相似文献   
60.
The number of subjects in a pharmacokinetic two‐period two‐treatment crossover bioequivalence study is typically small, most often less than 60. The most common approach to testing for bioequivalence is the two one‐sided tests procedure. No explicit mathematical formula for the power function in the context of the two one‐sided tests procedure exists in the statistical literature, although the exact power based on Owen's special case of bivariate noncentral t‐distribution has been tabulated and graphed. Several approximations have previously been published for the probability of rejection in the two one‐sided tests procedure for crossover bioequivalence studies. These approximations and associated sample size formulas are reviewed in this article and compared for various parameter combinations with exact power formulas derived here, which are computed analytically as univariate integrals and which have been validated by Monte Carlo simulations. The exact formulas for power and sample size are shown to improve markedly in realistic parameter settings over the previous approximations. Copyright © 2014 John Wiley & Sons, Ltd.  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