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171.
Ethylene oxide is a gas produced in large quantities in the United States that is used primarily as a chemical intermediate in the production of ethylene glycol, propylene glycol, non-ionic surfactants, ethanolamines, glycol ethers, and other chemicals. It has been well established that ethylene oxide can induce cancer, genetic, reproductive and developmental, and acute health effects in animals. The U.S. Environmental Protection Agency is currently developing both a cancer potency factor and a reference concentration (RfC) for ethylene oxide. This study used the rich database on the reproductive and developmental effects of ethylene oxide to develop a probabilistic characterization of possible regulatory thresholds for ethylene oxide. This analysis was based on the standard regulatory approach for noncancer risk assessment, but involved several innovative elements, such as: (1) the use of advanced statistical methods to account for correlations in developmental outcomes among littermates and allow for simultaneous control of covariates (such as litter size); (2) the application of a probabilistic approach for characterizing the uncertainty in extrapolating the animal results to humans; and (3) the use of a quantitative approach to account for the variation in heterogeneity among the human population. This article presents several classes of results, including: (1) probabilistic characterizations of ED10s for two quantal reproductive outcomes-resorption and fetal death, (2) probabilistic characterizations of one developmental outcome-the dose expected to yield a 5% reduction in fetal (or pup) weight, (3) estimates of the RfCs that would result from using these values in the standard regulatory approach for noncancer risk assessment, and (4) a probabilistic characterization of the level of ethylene oxide exposure that would be expected to yield a 1/1,000 increase in the risk of reproductive or developmental outcomes in exposed human populations.  相似文献   
172.
Colin Sumner has declared that the sociology of deviance as a research specialty was “dead? by 1975; later influential studies on norm-violating behavior appeared only in the specific area of criminology. We subjected this argument to empirical test through an analysis of the most-cited scholars and works in 263 textbooks, articles, and research notes appearing in the sociology of deviance from 1993 to 1999. We found some support for Sumner's claims: The majority of the most-cited scholars in devi-ance today conduct research in other areas, primarily in criminology. Furthermore, among the 31 most-cited works in our analysis, only two of 15 studies classified in the sociology of deviance appeared after 1975. We conclude with some thoughts about the factors that contribute to the rise and fall of research specializations in sociology.  相似文献   
173.
This study assesses the effect of population change on decade changes in the educational attainments of country of origin populations in the United States. Our data are derived from decennial censuses, NLMS, the World Bank, and INS. We find that changes in the share of country of origin populations with one or more years of post-secondary schooling are associated with selected components of population change during the 1980–1990 and 1990–2000 decades. The specific components include survivors during the decade, in-migration, and emigration of the foreign-born. Likewise, intra-generational mobility is found to be an important determinant of changes in educational attainment. The discussion addresses limitations of the data and suggests directions for future research as well as policy implications.  相似文献   
174.
Abstract

Objective: This study sought to (1) examine perceived stress and resources to cope with stress as predictors of emotional eating during the transition to college and (2) determine whether body mass index (BMI) moderated the emotional eating-stress relationship. Participants: Participants were 97 college freshmen (73% female; BMI: M = 25.3 kg/m2, SD = 5.7 kg/m2). Research was conducted in September 2012. Methods: Participants completed the Perceived Stress Scale, Emotional Eating Scale, and Eating and Appraisal Due to Emotions and Stress Questionnaire during the first month of college. Height and weight were measured objectively. Results: BMI moderated the relationship between perceived stress and emotional eating. Higher stress predicted greater emotional eating for the lower BMI groups, but not the highest group. Greater resources to cope with stress predicted lower emotional eating. Conclusions: Greater perceived stress and poorer resources to cope with stress may contribute to emotional eating during the transition to college. The relationship between perceived stress and emotional eating may vary by BMI.  相似文献   
175.
176.
Personality and organizational health: the role of conscientiousness   总被引:1,自引:0,他引:1  
Organizational health research identifies processes through which the work environment and individual differences combine to influence both individual and organizational outcomes. This study investigated the contribution of conscientiousness to organizational health. Research in the areas of occupational stress, work performance, and organizational climate was used to develop a framework for integrating different elements of organizational health. Within this framework, the work environment was assessed by perceptions of workload and role clarity ; individual well-being was assessed by psychological distress and job satisfaction ; and behaviour important for organizational success was assessed by contextual performance. Conscientiousness was investigated within the framework using self-reports from a sample of 104 Australian employees. Conscientiousness directly influenced contextual performance but did not influence well-being or perceptions of the work environment. Conscientiousness also reduced the impact of role clarity on both psychological distress and job satisfaction. The role of conscientiousness in a comprehensive model of organizational health is discussed.  相似文献   
177.
In the interest of developing a more holistic and integrated understanding of young children's experience of stories, this study describes preschoolers' emotional attachments to stories and the cultural beliefs and practices which surround such attachments. Thirty-two European-American, middle-class families, participated in an interview study of their children's story attachments, and five of these mothers also participated in a short-term, longitudinal diary study. Every child experienced at least two emotional attachments to stories. Children were captivated by stories presented in different media, with many attachments occurring around video stories in addition to books. They expressed their attachments by repeatedly requesting the story, expressing strong feelings, and enacting the story in pretend play. Story attachments were social in two fundamental ways: children created relationships with the characters in their favorite stories, and story attachments emerged in the context of relationships with caregivers whose beliefs and practices supported such attachments.  相似文献   
178.
179.
This article presents the results of a simulation study investigating the performance of an approach developed by Miller and Landis (1991) for the analysis of clustered categorical responses. Evaluation of this “two-step” approach, which utilizes the method of moments to estimate the extra-variation pardmeters and subsequently incorporates these parameters into estimating equations for modelling the marginal expectations, is carried out in an experimental setting involving a comparison between two groups of observations. We assume that data for both groups are collected from each cluster and responses are measured on a three-point ordinal scale. The performance of the estimators used in both “steps” of the analysisis investigated and comparisons are made to an alternative analysismethod that ignores the clustering. The results indicate that in the chosen setting the test for a difference between groups generally operatbs at the nominal α=0.05 for 10 or more clusters and hasincreasing power with both an increasing number of clusters and an inrreasing treatment effect. These results provide a striking contrasc to those obtained from an improper analysis that ignores clustering.  相似文献   
180.
The effects of motherhood timing on career path   总被引:2,自引:1,他引:1  
This paper estimates the effects of motherhood timing on female career path, using biological fertility shocks to instrument for age at first birth. Motherhood delay leads to a substantial increase in earnings of 9% per year of delay, an increase in wages of 3%, and an increase in work hours of 6%. Supporting a human capital story, the advantage is largest for college-educated women and those in professional and managerial occupations. Panel estimation reveals both fixed wage penalties and lower returns to experience for mothers, suggesting that a “mommy track” is the source of the timing effect.  相似文献   
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