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   959篇
  免费   40篇
管理学   206篇
民族学   4篇
人口学   75篇
丛书文集   9篇
理论方法论   113篇
综合类   13篇
社会学   464篇
统计学   115篇
  2022年   20篇
  2021年   9篇
  2020年   28篇
  2019年   26篇
  2018年   31篇
  2017年   31篇
  2016年   38篇
  2015年   34篇
  2014年   23篇
  2013年   151篇
  2012年   31篇
  2011年   26篇
  2010年   21篇
  2009年   22篇
  2008年   22篇
  2007年   38篇
  2006年   24篇
  2005年   26篇
  2004年   23篇
  2003年   20篇
  2002年   23篇
  2001年   21篇
  2000年   14篇
  1999年   18篇
  1998年   13篇
  1997年   10篇
  1996年   11篇
  1995年   9篇
  1994年   15篇
  1993年   13篇
  1992年   9篇
  1991年   13篇
  1990年   10篇
  1989年   7篇
  1988年   12篇
  1987年   9篇
  1986年   6篇
  1985年   13篇
  1984年   5篇
  1983年   11篇
  1982年   14篇
  1981年   7篇
  1980年   11篇
  1979年   7篇
  1978年   8篇
  1977年   9篇
  1976年   15篇
  1975年   10篇
  1974年   7篇
  1973年   7篇
排序方式: 共有999条查询结果,搜索用时 93 毫秒
1.
2.
3.
Many studies have provided evidence that, in birds, inexperienced breeders have a lower probability of breeding successfully. This is often explained by lack of skills and knowledge, and sometimes late laying dates in the first breeding attempt. There is growing evidence that in many species with deferred reproduction, some prebreeders attend breeding places, acquire territories and form pairs. Several behavioural tactics assumed to be associated with territory acquisition have been described in different species. These tactics may influence the probability of recruiting in the breeding segment of the population, age of first breeding, and reproductive success in the first breeding attempt. Here we addressed the influence of behaviour ('squatting') during the prebreeding period on demographic parameters (survival and recruitment probability) in a long-lived colonial seabird species: the kittiwake. We also investigated the influence of behaviour on reproductive trajectory. Squatters have a higher survival and recruitment probability, and a higher probability of breeding successfully in the first breeding attempt in all age-classes where this category is represented. The influence of behaviour is mainly expressed in the first reproduction. However, there is a relationship between breeding success in the first occasion and subsequent occasions. The influence of breeding success in the first breeding attempt on the rest of the trajectory may indirectly reflect the influence of behaviour on breeding success in the first occasion. The shape of the reproductive trajectory is influenced by behaviour and age of first breeding. There is substantial individual variation from the mean reproductive trajectory, which is accounted for by heterogeneity in performance among individuals in the first attempt, but there is no evidence of individual heterogeneity in the rate of change over time in performance in subsequent breeding occasions  相似文献   
4.
A dramatic change in fertility,family formation and living arrangements tookplace in the Czech Republic over the 1990s. Theestablishment of democracy, profound socialtransformation and transition to the marketeconomy affected the values and demographicbehaviour of the young Czech generation. Thispaper examines whether these demographic shiftscan be interpreted within the framework of thesecond demographic transition. The theoreticalpart discusses the idea of the transition,outlining three distinctive conceptualisations.Two of them – the view of the transition as aprogression of characteristic interrelateddemographic changes and a broader viewstressing the importance of underlyingideational factors – fit the Czech situationvery well. A comparison with the Netherlandsreveals that the onset of the transition in theCzech Republic may be clearly located in thefirst half of the 1990s, lagging two decadesbehind the Netherlands.  相似文献   
5.
6.
7.
The revised accreditation standards for marriage and family therapy programs (Manual on Accreditation, 1988) require that the curriculum reflect an emphasis on “issues of gender and ethnicity as they relate to marital and family therapy” (p. 13). Training approaches that are described in the professional literature tend to emphasize an understanding of ethnic minorities while deemphasizing the trainee's own ethnic and cultural roots. As such, training lacks dynamic integrity for the white, middle-class trainee. This paper describes a rationale for addressing the ethnic and cultural background of all family therapy trainees and provides training activities to accomplish this end.  相似文献   
8.
9.
This article presents a framework for using probabilistic terrorism risk modeling in regulatory analysis. We demonstrate the framework with an example application involving a regulation under consideration, the Western Hemisphere Travel Initiative for the Land Environment, (WHTI‐L). First, we estimate annualized loss from terrorist attacks with the Risk Management Solutions (RMS) Probabilistic Terrorism Model. We then estimate the critical risk reduction, which is the risk‐reducing effectiveness of WHTI‐L needed for its benefit, in terms of reduced terrorism loss in the United States, to exceed its cost. Our analysis indicates that the critical risk reduction depends strongly not only on uncertainties in the terrorism risk level, but also on uncertainty in the cost of regulation and how casualties are monetized. For a terrorism risk level based on the RMS standard risk estimate, the baseline regulatory cost estimate for WHTI‐L, and a range of casualty cost estimates based on the willingness‐to‐pay approach, our estimate for the expected annualized loss from terrorism ranges from $2.7 billion to $5.2 billion. For this range in annualized loss, the critical risk reduction for WHTI‐L ranges from 7% to 13%. Basing results on a lower risk level that results in halving the annualized terrorism loss would double the critical risk reduction (14–26%), and basing the results on a higher risk level that results in a doubling of the annualized terrorism loss would cut the critical risk reduction in half (3.5–6.6%). Ideally, decisions about terrorism security regulations and policies would be informed by true benefit‐cost analyses in which the estimated benefits are compared to costs. Such analyses for terrorism security efforts face substantial impediments stemming from the great uncertainty in the terrorist threat and the very low recurrence interval for large attacks. Several approaches can be used to estimate how a terrorism security program or regulation reduces the distribution of risks it is intended to manage. But, continued research to develop additional tools and data is necessary to support application of these approaches. These include refinement of models and simulations, engagement of subject matter experts, implementation of program evaluation, and estimating the costs of casualties from terrorism events.  相似文献   
10.
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