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   180篇
  免费   2篇
管理学   23篇
民族学   1篇
人口学   16篇
理论方法论   7篇
社会学   88篇
统计学   47篇
  2022年   4篇
  2021年   2篇
  2020年   6篇
  2019年   15篇
  2018年   8篇
  2017年   7篇
  2016年   6篇
  2015年   2篇
  2014年   5篇
  2013年   17篇
  2012年   60篇
  2011年   4篇
  2010年   9篇
  2009年   4篇
  2008年   6篇
  2007年   3篇
  2005年   3篇
  2002年   3篇
  2001年   1篇
  2000年   2篇
  1999年   2篇
  1996年   3篇
  1993年   2篇
  1991年   4篇
  1988年   1篇
  1987年   2篇
  1986年   1篇
排序方式: 共有182条查询结果,搜索用时 31 毫秒
81.
Abstract

Objective: To characterize contemporary college students requiring psychiatric hospitalization. Participants and methods: Sociodemographic and diagnostic information was gathered retrospectively and analyzed from the electronic medical records (EMRs) of the consecutive inpatient hospitalizations of 905 college students admitted to a psychiatric inpatient unit. Results: Significantly more females compared to males experienced the following: more hospitalizations, more family and financial stressors, more depression, and less psychotic and bipolar disorder. The most frequent diagnosis was a depressive disorder, followed by bipolar disorder, psychotic disorder, and personality disorder, most frequently borderline personality disorder. Half of participants had comorbid diagnoses with substance abuse most common. More than two-thirds of students endorsed social or intimate relationship, academic, and family challenges as psychosocial stressors. In all, 15% of participants had repeat admissions. Conclusions: The present study provides demographic data from a sample of psychiatrically hospitalized college students. Findings can help improve screening and identification of decompensation in college students.  相似文献   
82.
In this paper, we show that the widely used stationarity tests such as the Kwiatkowski Phillips, Schmidt, and Shin (KPSS) test have power close to size in the presence of time-varying unconditional variance. We propose a new test as a complement of the existing tests. Monte Carlo experiments show that the proposed test possesses the following characteristics: (i) in the presence of unit root or a structural change in the mean, the proposed test is as powerful as the KPSS and other tests; (ii) in the presence of a changing variance, the traditional tests perform badly whereas the proposed test has high power comparing to the existing tests; (iii) the proposed test has the same size as traditional stationarity tests under the null hypothesis of stationarity. An application to daily observations of return on U.S. Dollar/Euro exchange rate reveals the existence of instability in the unconditional variance when the entire sample is considered, but stability is found in subsamples.  相似文献   
83.

Pollen dispersal in tropical seed plants is established mainly by biotic vectors, both in intact and fragmented environments. In urban landscapes, the segregation of natural remnants by an artificial matrix can reduce pollinator foraging efficiency. It is unknown how nectarivorous bats, regarded as long-distance pollen dispersers, respond to such habitat structure combined with city-related factors. Here, we investigated the pollen dispersal pattern between spatially segregated individuals of the bat-pollinated Bignoniaceae Crescentia cujete within an urban environment. From 2015 to 2017, we assessed their spatiotemporal structure, breeding system and annual fruit set in order to relate these factors to the bat activity in the region. We employed fluorescent dyes as pollen analogues to infer the role of bats in pollen flow. Adding to the low density of individuals, we found a low daily flower emission and low flowering synchrony (S?=?0,092), all of which are traits that favor outcrossing. Individuals were distributed in two distant groups (>600 m), with no occurrence of dye flow between them. In contrast, flow within the same individual was intense, which points toward bats’ territorial behavior. C. cujete is self-compatible, but not autogamous; therefore, despite few outcross events, bats could be ensuring the plant’s year-round fruit production mainly through self-pollination. Our findings show restricted bat foraging extent, which affects overall pollen dispersal distance and population connectivity. These results can be extrapolated to natural metapopulations inserted in an urban matrix and serve as a groundwork for studying directly the effect of city-related factors on pollinator behavior.

  相似文献   
84.
85.
The revolution in information and communications technologies has put service tasks with strong tradability characteristics at high risk of being offshored. This article reviews studies proposing indicators of service tradability, exploring the labour market implications of service offshoring and developing theories to rationalize the facts. It suggests that both skill intensity and tradability are determinants of wage and employment effects. Nonetheless, the lack of widely accepted definitions of tradability, the absence of high‐quality data on service trade flows and the difficulty of measuring import competition at higher disaggregation levels pose difficulties in achieving further progress, pointing to areas for future research.  相似文献   
86.
Renato Brunetta 《LABOUR》1993,7(2):91-127
The — in some ways innovative — objective of this paper is the study of the dynamics of the disequilibria provoked by the emergence of involuntary unemployment in the labour market, and the role of the economic policy authorities (through welfare, incomes and employment policies), with the aim of discovering if there is an explicit or implicit consistency between the role of these authorities, their actions and the pursuit of maximum employment (or elimination of the disequilibria). We seek to show, in other words, whether the actions of the government authorities conform to their accepted meaning (the aim of reducing the disequilibria) or whether, on the contrary, it may not be possible to put forward a different interpretation, if sociopolitical variables are introduced into the analysis, thus placing in the foreground different and alternative objecties such as “conflict control” and/or the reaching of a consensus between the different social partners. The paper therefore begins by analysing separately the historical-theoretical characteristics of the individual policies considered — welfare, incomes and employment — in their evolution (with particular reference to the last two decades), and then attempts an interpretative key in synthesis, by resorting to a specific model derived from the theories of disequilibria.  相似文献   
87.
Renato Brunetta 《LABOUR》1991,5(1):75-100
Abstract. In recent years, labour economics has been the area of study of most interest to economists, both from the theoretical and practical perspectives. The new field of labour microeconomics and the resultant new approaches that have arisen are a fundamental part of what has recently been called ‘microeconomic foundations’. Despite the newness of this topic, recent developments are in fact the result of phenomena recognized throughout the history of economic thought. This paper begins by analyzing the historical and theoretical origins of labour economics, and provides an overview of labour economics theory during the 1960s. 1970s and 1980s. It goes on to examine the relation between the labour market and technological innovation, and labour policy measures at the microeconomic and macroeconomic levels. Finally, it underscores the need for a theoretical construct that sets Keynesian and neoclassical explanations of unemployment in the same framework as demographic, social, institutional, time and economic factors.  相似文献   
88.
This investigation approaches the levels and the predictors of loneliness among migrant youths from returned migrant families from France to Portugal. Three research questions guided the study: (1) Does loneliness of migrant youths differ from those who have never migrated? (2) Are migrant youths’ re-acculturation factors related to their loneliness? (3) Is the adaptation of migrant youths linked to their loneliness? The answer to these questions is important to improve migrant youths’ re-acculturation experiences and their adaptation. The sample included 222 youths from returned migrant families from France. Participants completed the brief Portuguese version of the Revised UCLA Loneliness Scale (ULS-6), in addition to measures of re-acculturation and adaptation. A control group comprised of 211 Portuguese adolescents who have never migrated was also involved in the investigation. Youths from returned migrant families showed lower levels of loneliness than their native Portuguese counterparts who have never migrated. Demographic, re-acculturation, and adaptation factors were significantly related to adolescents’ loneliness. Major predictors of loneliness were age at return, contacts with peers without migratory experience, perceived discrimination, stressful adaptation experience, and satisfaction with life.  相似文献   
89.
90.
During the recent decades Brazil has experienced an exponential growth in the aviation sector resulting in an increasing workforce. The aircraft maintenance industry stands out, where the workers have to handle different kind of objects. The aim of this study was to evaluate psychosocial indicators as well as musculoskeletal symptoms and disorders among aircraft maintenance workers. One hundred and one employees were evaluated (32.69 ± 8.25 yr, 79.8 ± 13.4 kg, and 1.75 ± 0.07 m). Musculoskeletal symptoms and disorders were assessed through the Nordic Musculoskeletal Questionnaire (NMQ) and a standardized physical examination. The Job Content Questionnaire (JCQ) and the Utrecht Work Engagement Scale (UWES) were applied to evaluate psychosocial indicators. Results of the NMQ indicate the lower back as the most affected body region. On the other hand, the physical examination has shown clinical diagnosis of shoulder disorders. Neck, upper back and ankle/foot were also reported as painful sites. Most of workers have active work-demand profile and high work engagement levels. We suggest that musculoskeletal symptoms may be related to high biomechanical demand of the tasks performed by workers, what must be further investigated.  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