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   5101篇
  免费   157篇
管理学   681篇
民族学   24篇
人口学   525篇
丛书文集   20篇
教育普及   1篇
理论方法论   487篇
综合类   62篇
社会学   2395篇
统计学   1063篇
  2023年   33篇
  2021年   51篇
  2020年   89篇
  2019年   117篇
  2018年   130篇
  2017年   194篇
  2016年   139篇
  2015年   81篇
  2014年   133篇
  2013年   784篇
  2012年   161篇
  2011年   145篇
  2010年   125篇
  2009年   111篇
  2008年   137篇
  2007年   128篇
  2006年   149篇
  2005年   112篇
  2004年   113篇
  2003年   76篇
  2002年   98篇
  2001年   132篇
  2000年   122篇
  1999年   132篇
  1998年   101篇
  1997年   87篇
  1996年   93篇
  1995年   68篇
  1994年   60篇
  1993年   87篇
  1992年   89篇
  1991年   97篇
  1990年   78篇
  1989年   78篇
  1988年   61篇
  1987年   68篇
  1986年   62篇
  1985年   75篇
  1984年   66篇
  1983年   69篇
  1982年   44篇
  1981年   41篇
  1980年   37篇
  1979年   47篇
  1978年   38篇
  1977年   33篇
  1976年   34篇
  1975年   32篇
  1974年   40篇
  1973年   29篇
排序方式: 共有5258条查询结果,搜索用时 15 毫秒
321.
The purpose of this study was to provide an initial investigation into the work–family conflict (WFC) experiences of individuals who hold a second job. Specifically, we proposed two opposing theoretical arguments regarding the relationship between WFC and four measures of well-being: life satisfaction, physical health, emotional exhaustion, and exercise for individuals who hold two jobs. In a sample of individuals working two jobs, we tested whether the effects of WFC arising from the first job and from the second job exerted an additive or interactive effect on employee well-being. Our results indicated that for emotional exhaustion, physical symptoms, and life satisfaction, the effects of WFC from two jobs are interactive; but that for exercise, the effects of WFC from two jobs are additive. In both cases, the additional WFC experienced as a result of working a second job contributed to the prediction of employee well-being over and above WFC from the first job. Results are discussed within the context of relevant theory, and suggestions are made for future research.  相似文献   
322.
Married Vietnamese immigrant women often face multiple stressors related to sociocultural adaptation and new family lives in South Korea. The purpose of this paper is to identify the different influences of acculturative and family life stress on depressive symptoms among Vietnamese immigrant wives. Data were collected through a questionnaire survey of 301 married Vietnamese immigrant women residing in South Korea. The study utilized linear regression analysis to test the relationships between the variables. The findings show that both acculturative and family life stress are positively related to depressive symptoms. Family life stress influences depressive symptoms to a greater extent than acculturative stress. The study emphasizes the significance of family‐related stress on mental health among married Vietnamese immigrant women in Korea and provides some implications for research, clinical practice, and policy.  相似文献   
323.
On-going human population growth and changing patterns of resource consumption are increasing global demand for ecosystem services, many of which are provided by soils. Some of these ecosystem services are linearly related to the surface area of pervious soil, whereas others show non-linear relationships, making ecosystem service optimization a complex task. As limited land availability creates conflicting demands among various types of land use, a central challenge is how to weigh these conflicting interests and how to achieve the best solutions possible from a perspective of sustainable societal development. These conflicting interests become most apparent in soils that are the most heavily used by humans for specific purposes: urban soils used for green spaces, housing, and other infrastructure and agricultural soils for producing food, fibres and biofuels. We argue that, despite their seemingly divergent uses of land, agricultural and urban soils share common features with regards to interactions between ecosystem services, and that the trade-offs associated with decision-making, while scale- and context-dependent, can be surprisingly similar between the two systems. We propose that the trade-offs within land use types and their soil-related ecosystems services are often disproportional, and quantifying these will enable ecologists and soil scientists to help policy makers optimizing management decisions when confronted with demands for multiple services under limited land availability.  相似文献   
324.
David T. Palmer   《Serials Review》2009,35(3):138-141
The Pacific Rim Library (PRL) is an initiative of the Pacific Rim Digital Library Association (PRDLA). The project began in 2006 using the OAI-PMH paradigm and now holds over 300,000 records harvested from OAI data provider libraries around the Pacific. PRL's goal is to enable the sharing of digital collections amongst PRDLA members and the world, but greater unexpected benefits have been discovered. Through mirroring their metadata, PRL increases the chance that their data will be discovered in Google and other general search engines. With its many disparate collections, PRL is not a repository for traditional information discovery and retrieval. Initially users will bounce from a Google hit to the PRL metadata record in Hong Kong and then begin an intensive search on the original site which hosts the full digital object, in Vancouver, Honolulu, Wuhan, Singapore, or other PRDLA member location.  相似文献   
325.
This paper experimentally investigates how risk attitudes mitigate leadership effectiveness in a collective setting with projects that exhibit both free riding and coordination problems. We take two novel approaches: 1) the introduction of economic game theory to psychological studies of leadership, and 2) the application of the leadership ontology of Drath et al. (2008) as a cross-disciplinary integrative framework. Leadership here is focused on the presence or absence of direction, alignment, and commitment as well as antecedent beliefs and practices that are held within a collective (for us, our experimental participants). Our leadership context is stripped down to very minimal conditions: three group members, an investment decision, and the introduction of information regarding group members' attitudes toward risk. We find that the mere mention of risk attitude (whether risky or risk averse) undermines leadership effectiveness in mitigating free riding for our 420 experimental participants. Our study's primary implications lie in the application of game theory methodology to the psychological study of leadership, the introduction of relevant individual difference constructs to economic studies of leadership, and the advocation of the Drath et al. (2008) framework as a helpful integrative mechanism for interdisciplinary leadership research.  相似文献   
326.
Gart (1972) ottered a Statistic on testing the hypothesis of no second-order interaction in a 2×s×t contingency table. The statistic was tn be used as an asymptotic chi-square with (s-1) (t-1) degrees of freedom. We show that this statistic suiters from the drawback that unless certain side conditions hold, the statistic would reject the null hypothesis with probability approaching one asymptotically even in the null case. Hence the statistic is not strictly valid for the hypothesis for which it was intended.  相似文献   
327.
We establish the exact expressions of X1/X2 and of X1/(X1+X2), where X1 and X2 are independent beta random variables of the first type, and provide some of their applications, in reliability and availability.  相似文献   
328.
Biomedical research has made tremendous advances during the last decade in improving human health and well being. In spite of these advances, research has encountered serious emerging challenges as it moves across boarders and confronts different societies with different cultural practices, beliefs, moral thoughts and different values. A pervasive and perplexing issue affecting the current advances in research is the perception that research might end up exploiting populations unless it is conducted in the context of a strong ethical framework. Furthermore, informed consent has increasingly become a thorny area for researchers when considering what should be done when introducing the process into a community, especially if the process might destroy the traditional value system and customs of the community. In this paper, I argue that community consent is an unethical process which should be subverted for community dialogue and community education in research in Africa.  相似文献   
329.
Homoscedastic and heteroscedastic Gaussian mixtures differ in the constraints placed on the covariance matrices of the mixture components. A new mixture, called herein a strophoscedastic mixture, is defined by a new constraint, This constraint requires the matrices to be identical under orthogonal trans¬formations, where different transformations are allowed for different matrices. It is shown that the M-step of the EM method for estimating the parameters of strophoscedastic mixtures from sample data is explicitly solvable using singular value decompositions. Consequently, the EM-based maximum likelihood estimation algorithm is as easily implemented for strophoscedastic mixtures as it is for homoscedastic and heteroscedastic mixtures. An example of a “noisy” Archimedian spiral is presented.  相似文献   
330.
Composite samples are formed by physically mixing samples. Usually, composite samples are used to reduce the overall cost associated with analytical procedures that must be performed on each sample, but they can also be used to protect the privacy of individuals.

Composite sampling can reduce the cost of identifying individual cases that have a certain trait, such as those with a rare disease or those exceeding pollution-level standards. Not much is lost by applying this method as long as the trait is relatively rare.

Composite sampling can reduce the cost of estimating the mean of some process. When samples are composited, the ability to estimate the variance is lost. In spite of this, the potential savings are so great that composite samples have been used.

Much of this paper deasl with the variance of estimators based on composite sampling when the porportions of hte original samples comprising the composite sample are actually random. Taking repeated samples and measurements on several composite samples complicates the prodcedure, but allows the estimation of between and within variation as well as measurement error.  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