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   2022篇
  免费   57篇
管理学   188篇
民族学   19篇
人口学   278篇
丛书文集   7篇
理论方法论   150篇
综合类   82篇
社会学   877篇
统计学   478篇
  2023年   35篇
  2022年   32篇
  2021年   41篇
  2020年   92篇
  2019年   106篇
  2018年   185篇
  2017年   175篇
  2016年   148篇
  2015年   72篇
  2014年   108篇
  2013年   346篇
  2012年   193篇
  2011年   84篇
  2010年   68篇
  2009年   69篇
  2008年   58篇
  2007年   47篇
  2006年   32篇
  2005年   24篇
  2004年   28篇
  2003年   16篇
  2002年   19篇
  2001年   11篇
  2000年   20篇
  1999年   8篇
  1998年   14篇
  1997年   8篇
  1996年   10篇
  1995年   3篇
  1994年   5篇
  1993年   3篇
  1992年   6篇
  1991年   4篇
  1990年   1篇
  1989年   1篇
  1987年   1篇
  1984年   1篇
  1983年   1篇
  1980年   1篇
  1973年   1篇
  1971年   1篇
  1968年   1篇
排序方式: 共有2079条查询结果,搜索用时 19 毫秒
81.
Activity and species-specific responses of insectivorous bats in different urban-forest conditions provides a general perspective on the adaptability and vulnerability of bat species towards urbanization intensity. Here we evaluated species richness and activity patterns of aerial insectivorous bats across an urbanized landscape in the highlands of Chiapas, in Mexico. Acoustic monitoring of echolocation calls was conducted for 27 nights over a period of four months. Species richness and relative activity of insectivorous bats were estimated in a landscape with different conditions of urbanization intensity: urban areas, non-urban and forest areas. We identified a total of 14 bat species and three phonotypes. Bat species richness and relative activity was similar (X2 = 0.568, gl = 2, p > 0.05), but species composition differed among conditions. We observed a significant higher occurrence of Bauerus dubiaquercus, Eptesicus brasiliensis and Myotis californicus in forest sites. Urban sites presented higher occurrence of Molossus rufus and phonotype Molossidae 2, while non-urban sites presented a higher occurrence of Eptesicus furinalis and phonotype Molossidae 2. We were able to identify bat species according to their relative activity in relation todifferent landscape conditions. Species of the Molossidae family presented the highest activity in urban sites, which was positively affected by the number of streetlights, while species of the Vespertilionidae presented the highest activity in forest sites, which was positively related totree density. While urbanization tends to diminish native biodiversity and alter faunal communities, our results show a similar richness and relative activity of aerial insectivorous bats along the urban ecosystem. The effect of urbanization intensity becomes more apparent in species-specific bat activity; the response of species towards particular habitat conditions depends on local habitat quality and characteristics (i.e., presence of streetlights, vegetation cover and tree density).  相似文献   
82.
Does urbanization affect key life-history traits in native organisms? Some studies show that urban areas reduce diversity in certain taxa, but there is little insight into how these environments affect physiological and ecological traits. Urban areas have distinct physical structure and ecological processes compared to original habitats. The environmental changes associated with urban areas can influence the costs and benefits of different traits and behaviors of local organisms. Some of these effects have been explored in groups such as birds, but we might expect stronger effects in animals with reduced mobility, such as amphibians. Importantly, the effects of urban habitats on amphibians have not been explored, in spite that these are the most threatened vertebrate group in the world. Here, we compared three main traits related to the fitness of amphibians in urban and natural habitats: body size, body condition and immune response. To test the generality of our results, we assessed adult males of four amphibian species. We found that the body size was larger in urban environment populations in three of four studied species, while the body condition was better in the urban populations of two aquatic newt species. Finally, we found no effect of urbanization on the immune response of individuals of any species. In conclusion, we show that different species of amphibians may be affected differently by anthropogenic habitat alteration depending on their specific ecology.  相似文献   
83.
This paper explores the relationship between governance and social innovation in the area of organizations. In order to understand that relationship, we offer a model that links the absorptive capacity of knowledge [Cohen and Levinthal 1990. “Absorptive Capacity: A new Perspective on Learning and Innovation.” Administrative Science Quarterly 35 (1): 128–152] with open innovation [Chesbrough and Di Minin 2014. “Open Social Innovation.” In New Frontiers in Open Innovation, edited by H. Chesbrough, W. Vanhaverbeke, and J. West, 169–187. Oxford: Oxford University Press]. On the basis of the pilot study Regional Social Innovation Index carried out in the Basque Country (Spain), we empirically explore three types of governance (social, inter-organizational, and sustainable) in social innovation projects propelled by four types of key agents at a regional level: profit and non-profit organizations, universities, and technology centers. The proposed governance Index in Social Innovation contributes to discussions about governance and social innovation at a micro level and, and to the debate about the production of indicators in social innovation.  相似文献   
84.
This paper aims to contribute to the existing studies on the young women’s transition to adulthood in the case of Turkish women’s exclusion from the labour market. The issue is discussed largely within the boundaries of traditional gender restrictions that keep women out of employment. Herein, we argue that the gender-based control of young women, perceived as the reason for their exclusion from the labour market, may be used by disadvantaged women as a way of avoiding difficult and unfavourable employment situations. Similarly, the gender roles imposed on men could also not be fulfilled due to the same restrictive labour market conditions. Furthermore, we suggest that the poverty simultaneously strengthens and erodes the very base of the traditional gender structure for both young women and young men, while forcing the young women out of employment and the young men to the unstable working conditions. This argument is based on a study conducted in Alt?nda?, Ankara with a sample of 279 females and 340 males aged between 15 and 24. A mixed methodology, comprising a survey questionnaire followed by 60 in-depth interviews and 4 focus group discussions, was employed for this study.  相似文献   
85.
This article studies 28 dual-income Spanish childless couples who were undoing gender in routine domestic work. We understand ‘undoing gender’ as defined by Deutsch [(2007). Undoing gender. Gender & Society, 21, 106–127, p. 122]: ‘social interactions that reduce gender difference’. The dual-earner couples came from different socio-economic backgrounds and were interviewed in four different Spanish towns in 2011. The analysis shows that resources in a wide sense, time availability, external help, ideas about fairness, and complex gender attitudes are key interdependent factors that can weave together to form different configurations leading to a non-mainstream division of housework. All configurations were based on principles of gender equality: some couples found it fair to have a 50/50 division of domestic work, others a 50/50 division of all work (paid and unpaid); and a third group showed conflicts in practice. These couples’ ways of undoing gender illustrate the external, individual, and couple circumstances under which spouses are able to achieve a non-traditional construction of unpaid work.  相似文献   
86.
Our analysis of an informal event involving Chinese and Spanish students and lecturers displays the cumulative nature of stance negotiation in multicultural settings. It also highlights the role of sociocultural and ideological elements in stancetaking, not only in relation to the positions adopted by the participants, but also in the successive redefinition and reframing of the stance objects. Sociocultural and ideological elements are also crucial for the collective construction of intersubjectivities, particularly among mobile citizens. The way in which our international students managed to overcome misalignments, the values and ideologies evoked within the interaction, reveal nuances of cosmopolitanism that point to a globalization of tastes triggered by multiculturalism and the worldwide expansion of capitalism. Sharing a cosmopolitan orientation, however, did not prevent ideological contradictions among the participants. An analysis of how these were voiced and negotiated allows grasping the remarkably wide spectrum of cosmopolitanism(s) today.  相似文献   
87.
We present the results of the use of a cognitive behavioral therapeutic intervention tool to improve the mental, physical, and social health of a group of long-term unemployed women in Spain. Method: We sent automated text messages (SMS) to the mobile phones of long-term unemployed women selected at random from public social services. During a 28-day intervention period, women received four daily automated text messages on her mobile phone on a predetermined hourly schedule. We measured depression symptoms at the start and end of the intervention and we analyzed qualitative data to determine the acceptability of a remote SMS program. Results: Depression symptoms using the Personal Health Questionnaire-9 (PHQ-9), went from an average of 13.8 at baseline to 4.9 at the end of 28 days (p?=?0.89). One hundred percent of the women reported that they liked receiving the text messages and most found them helpful.  相似文献   
88.
ABSTRACT

Feminist scholars have challenged the neutrality of policymaking processes and the outputs resulting from these processes. However, some elements of policymaking have not been studied as well as others. In this article I explore the concept of evaluation from a gender+ perspective as an essential step for a complete gender mainstreaming strategy, which can help to identify gender issues that should be integrated into the content of evaluated policies and to ensure gender does not get lost in the policymaking process. This exploration is carried out by relying on feminist policy and evaluation studies.  相似文献   
89.
In applications of Gaussian processes (GPs) where quantification of uncertainty is a strict requirement, it is necessary to accurately characterize the posterior distribution over Gaussian process covariance parameters. This is normally done by means of standard Markov chain Monte Carlo (MCMC) algorithms, which require repeated expensive calculations involving the marginal likelihood. Motivated by the desire to avoid the inefficiencies of MCMC algorithms rejecting a considerable amount of expensive proposals, this paper develops an alternative inference framework based on adaptive multiple importance sampling (AMIS). In particular, this paper studies the application of AMIS for GPs in the case of a Gaussian likelihood, and proposes a novel pseudo-marginal-based AMIS algorithm for non-Gaussian likelihoods, where the marginal likelihood is unbiasedly estimated. The results suggest that the proposed framework outperforms MCMC-based inference of covariance parameters in a wide range of scenarios.  相似文献   
90.
In this work, we derive the copulas related to vectors obtained from the so-called chaotic stochastic processes. These are defined by the iteration of certain piecewise monotone functions of the interval [0, 1] to some initial random variable. We study some of its properties and present some examples. Since often these types of copulas do not have closed formulas, we provide a general approximation method which converges uniformly to the true copula. Our results cover a wide class of processes, including the so-called Manneville–Pomeau processes. The general theory is applied to the parametric estimation in certain chaotic processes. A Monte Carlo simulation study is also presented.  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