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   3653篇
  免费   98篇
管理学   560篇
民族学   32篇
人才学   1篇
人口学   336篇
丛书文集   31篇
理论方法论   345篇
综合类   21篇
社会学   1891篇
统计学   534篇
  2023年   18篇
  2021年   23篇
  2020年   54篇
  2019年   77篇
  2018年   77篇
  2017年   98篇
  2016年   93篇
  2015年   81篇
  2014年   79篇
  2013年   694篇
  2012年   92篇
  2011年   108篇
  2010年   90篇
  2009年   75篇
  2008年   114篇
  2007年   114篇
  2006年   80篇
  2005年   92篇
  2004年   91篇
  2003年   89篇
  2002年   116篇
  2001年   84篇
  2000年   82篇
  1999年   64篇
  1998年   58篇
  1997年   58篇
  1996年   45篇
  1995年   61篇
  1994年   54篇
  1993年   50篇
  1992年   45篇
  1991年   52篇
  1990年   42篇
  1989年   40篇
  1988年   59篇
  1987年   57篇
  1986年   26篇
  1985年   39篇
  1984年   46篇
  1983年   57篇
  1982年   32篇
  1981年   35篇
  1980年   29篇
  1979年   34篇
  1978年   39篇
  1977年   31篇
  1976年   35篇
  1975年   28篇
  1974年   18篇
  1972年   17篇
排序方式: 共有3751条查询结果,搜索用时 15 毫秒
101.
Differential equations have been used in statistics to define functions such as probability densities. But the idea of using differential equation formulations of stochastic models has a much wider scope. The author gives several examples, including simultaneous estimation of a regression model and residual density, monotone smoothing, specification of a link function, differential equation models of data, and smoothing over complicated multidimensional domains. This paper aims to stimulate interest in this approach to functional estimation problems, rather than provide carefully worked out methods.  相似文献   
102.
Bootstrap tests: how many bootstraps?   总被引:3,自引:0,他引:3  
In practice, bootstrap tests must use a finite number of bootstrap samples. This means that the outcome of the test will depend on the sequence of random numbers used to generate the bootstrap samples, and it necessarily results in some loss of power. We examine the extent of this power loss and propose a simple pretest procedure for choosing the number of bootstrap samples so as to minimize experimental randomness. Simulation experiments suggest that this procedure will work very well in practice.  相似文献   
103.

There have been few studies investigating the relationship between the built environment and the status of bird distributions in small island tropical urban areas. We present a study investigating the relationship between bird species richness, abundance and assemblage to the built environment in Suva, Fiji. Field surveys were taken at 54 randomly selected sites throughout the city, stratified by three building density classes and the central business district (CBD). At each site bird counts were recorded, along with environmental data such as average building height, within a 150 m radius. Land-use information was obtained from screen digitized high-resolution satellite imagery within the same radius. Distance to undeveloped patches of land within the urban area was calculated using a GIS. Analysis of the effects of the built environment was carried out for all species, and for exotic and native species separately. Abundance of exotics was significantly higher in the central business district (CBD) than all other urban density classes, and significantly higher than natives in all other density classes. We found a negative relationship between native species richness and distance to undeveloped patches, but no relationship for exotics. Species assemblage was not related to urban density class. We conclude that the status of native and exotic bird species in Suva is similar to what has been found in urban areas in temperate climates, and conservation efforts should focus on minimizing the amount of heavily urbanized “core areas” and protecting undeveloped areas of forested vegetation to improve bird biodiversity in small tropical islands cities.

  相似文献   
104.
The number of practicing behavior analysts who hold Behavior Analyst Certification Board (BACB) certification has substantially increased in the past decade. Some have mistakenly interpreted the BACB’s certification requirements as being specific to the autism and intellectual disabilities practice area. We present key BACB requirements, describe how they are practice-area neutral, and provide specific examples of their relevance to organizational behavior management.  相似文献   
105.
Recent concern over increasing loss of biodiversity has prompted considerable interest in the role of urban green spaces as reservoirs of local biodiversity. This study assessed the diversity of three indicator taxa - plants, ants and birds - on golf courses spanning a wide range of environmental variation in terms of climate, elevation, course age, size and connectivity to native woodland. Species richness and community composition was further compared between contrasting on-course habitat types that reflect different management intensities. We identified a set of taxon-specific environmental correlates indicating an intricate interplay of landscape- and local-scale variables that affect local species diversity. Our results show that floristic diversity is positively associated with the amount of rainfall, whereas ant and bird diversity are related to local-scale factors, particularly the number of trees and the size of water features on a site. The amount of on-course native habitat was a strong predictor of plant and ant diversity and was also associated with the number of unique species at the site level; this reinforces the value of remnant habitat patches as local biodiversity reservoirs that represent mini hot-spots in an otherwise species-poor urban landscape. Community composition for all three taxa differed markedly between non-playing and playing areas, with boundary and remnant habitats generally having more diverse, species-rich communities. Our results suggest that local floral and faunal biodiversity on urban golf courses can be enhanced by creating woody non-playing areas and, especially, by preserving, restoring or expanding remnant habitats.  相似文献   
106.
As a contribution to the ongoing tradition of critically assessing documents for research, this paper aims to highlight materiality as a key factor in the co-shaping of knowledge derived from digital documents. The paper first builds upon prior debates in document studies with work from the fields of Science and Technology Studies, and Communication Studies, to establish the role of document materiality in the interpretative process. By first establishing digital documents’ material reality as electrical signal, the paper then discusses the interpretative role of software, in both the representation of that signal for human interpretation and the production of the document through software tools. Finally, the paper considers the implications for persistence and access to digital documents posed by their material reality and the private archival contexts in which they often reside.  相似文献   
107.
Although a growing body of research has explored the early development of social evaluation, no research has directly compared social evaluations of infants between different cultures. In addition, there has been little understanding regarding socialization's effects on this ability. The goal of this study was to expand on earlier findings on social evaluation in infants by investigating a broader sample from two cultures, and to explore the influence of maternal socialization on infants’ social evaluation. Using the violation of expectations and the preferential reaching paradigm, four groups aged 6‐, 9‐, 12‐, and 15–18 months and their mothers from Japan and the United States (159 dyads) were compared in terms of spontaneous social evaluations. Japanese and European American infants showed similar performance in dishabituation to the inconsistent behavior and in their reaching preference for prosocial over antisocial agents, indicating that the emergence of spontaneous social evaluation is not culture‐specific. Furthermore, our study provides a novel finding regarding the relationship between mothers’ socially evaluative speech and infants’ preference for prosocial over antisocial agents. These results suggest that the development of sociomoral understanding results from complicated interactions among evolutionary, cognitive, and social factors.  相似文献   
108.
This research uses nationally representative data to study how economic resources and inequalities are associated with life satisfaction of Chinese residents. We construct economic resource and inequality measures from expenditure rather than from income, after confirming that expenditure inequality is a better measure in the Chinese context. We find that economic inequalities in general are negatively associated with life satisfaction, and that this association is larger for inequalities in the lower half of the distribution than those in the upper half of the distribution. We further explore the mechanisms under which inequality can be associated with life satisfaction, and find that aspiration is potentially one important channel.  相似文献   
109.
Studies regarding the effectiveness of homework assignments in cognitive‐behavioral treatments have demonstrated mixed results. This study investigated predictors of compliance with homework recommendations and the time‐varying relationship of recommendation completion with treatment response in a brief couples' intervention (= 108). More satisfied couples and couples with more motivation to change completed more recommendations, whereas couples with children completed fewer. The association between recommendation completion and treatment response varied with the passage of time, with the strongest effect observed 6 months after the intervention, but no discernible differences at 1 year postintervention. Couples that completed more recommendations experienced more rapid treatment gains, but even those couples doing substantially fewer recommendations ultimately realized equivalent treatment effects, although they progressed more slowly. Implications are discussed.  相似文献   
110.
This qualitative study examined the experiences of alternative school students as they participated in a mindfulness skills program. A 7-month school-based mindfulness skills program was integrated into the Grade 10 curriculum for high school students (N = 19; 10 boys and 9 girls, ages 15–17). Students engaged in mindfulness practices twice weekly during class time. Students practiced breath awareness, and seated, walking, and lying mindfulness meditation during the course of the program. Students completed initial and final questionnaires about their experiences as well as written journal entries based on their experiences in the program. At the completion of the program, 14 of the 19 program completers were interviewed (6 boys and 8 girls). Data analysis yielded two broad areas of perceived benefits of participation in the mindfulness skills program: intrapersonal benefits and interpersonal benefits. Intrapersonal benefits included themes of self-awareness and self-regulation (including cognition, emotions, and behavior). Interpersonal benefits included themes of building relationships (with peers, family members, and teachers) and learning to trust. These findings may be useful when planning school-based mindfulness programs and may serve as a guide for researchers studying mindfulness practices for youth.  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