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   3331篇
  免费   130篇
管理学   564篇
民族学   15篇
人才学   1篇
人口学   230篇
丛书文集   26篇
理论方法论   468篇
综合类   42篇
社会学   1531篇
统计学   584篇
  2023年   18篇
  2021年   21篇
  2020年   48篇
  2019年   85篇
  2018年   83篇
  2017年   113篇
  2016年   121篇
  2015年   80篇
  2014年   85篇
  2013年   471篇
  2012年   137篇
  2011年   113篇
  2010年   104篇
  2009年   100篇
  2008年   115篇
  2007年   122篇
  2006年   101篇
  2005年   109篇
  2004年   105篇
  2003年   97篇
  2002年   103篇
  2001年   87篇
  2000年   77篇
  1999年   63篇
  1998年   51篇
  1997年   68篇
  1996年   57篇
  1995年   42篇
  1994年   48篇
  1993年   49篇
  1992年   31篇
  1991年   33篇
  1990年   41篇
  1989年   37篇
  1988年   34篇
  1987年   31篇
  1986年   23篇
  1985年   35篇
  1984年   37篇
  1983年   21篇
  1982年   32篇
  1981年   30篇
  1980年   27篇
  1979年   31篇
  1978年   17篇
  1977年   11篇
  1976年   28篇
  1975年   14篇
  1974年   18篇
  1973年   16篇
排序方式: 共有3461条查询结果,搜索用时 680 毫秒
981.
Parental age at child’s birth—which has increased for U.S. children in the 1992–2000 birth cohorts—is strongly associated with an increased risk of autism. By turning a social demographic lens on the historical patterning of concordance among twin pairs, we identify a central mechanism for this association: de novo mutations, which are deletions, insertions, and duplications of DNA in the germ cells that are not present in the parents ’ DNA. Along the way, we show that a demographic eye on the rising prevalence of autism leads to three major discoveries. First, the estimated heritability of autism has been dramatically overstated. Second, heritability estimates can change over remarkably short periods of time because of increases in germ cell mutations. Third, social demographic change can yield genetic changes that, at the population level, combine to contribute to the increased prevalence of autism.  相似文献   
982.
We analyse the adjustment of networks comprising of weighted positive (P) and negative (N) symmetric relations under the impact of various balancing rules. Five kinds of rules are studied: (1) a local minimal edge adjustment which is a special case of, (2) a local pressure based rule, (3) a local sign based rule, (4) a global rule and (5) rules varying on a local to global dimension. The convergence and convergent proportions of different 3-cycles and, thus the impact upon β(3) balance, under the different kinds of adjustment rule are studied both analytically and through simulation. The effects of network size (n), density (d) and the initial proportion of positive edges (α0) upon the convergence of 3-cycles and, thus, balance and the eventual implications for the process of group formation are explored.  相似文献   
983.
Within the field of national security and counterterrorism a great need exists to understand covert organizations. To better understand these cellular structures we model and analyze these cells as a collection of subsets of all participants in the covert organization, i.e., as hypergraphs or affiliation networks. Such a covert affiliation network structure is analyzed by evaluating the one-mode projection of the corresponding hypergraph. First we provide a characterization of the total distance in the one-mode projection using its corresponding cell-shrunken version. Secondly we evaluate the one-mode projection with respect to the secrecy versus information tradeoff dilemma every covert organization has to solve. We present and analyze affiliation networks representing common covert organizational forms: star, path and semi-complete hypergraphs. In addition we evaluate an example of a covert organization wishing to conduct an attack and compare its performance to that of the common covert organizational forms. Finally we investigate affiliation networks that are optimal in the sense of balancing secrecy and information. We show how any affiliation tree can be improved by altering its structure. Finally we prove that among covert organizational forms in the class of hypertrees with the same number of cells uniform star affiliation networks are optimal.  相似文献   
984.
Practitioners who view intimate partner violence as a set of strategies aimed at maintaining positions of power and privilege often face an engagement dilemma when men at their first contact talk of themselves as disempowered by circumstances such as separation, loss of access to children, legal problems, substance abuse issues, and their own history of being abused. This paper explores how a language-oriented approach to violence can assist practitioners in responding to abuser's current perceptions while avoiding collusion with justifications for violence. It examines common ways of speaking that men will employ to justify their violence then explores practical ways to identify and neutralized these messages before exploring personal opportunities for change.  相似文献   
985.
In the context of government decentralisation and integration of services, over the last 15 years Sweden has been developing an all‐day school based on inter‐professional teamworking and adopting a holistic approach to working with children. The article describes these recent educational reforms in Sweden, which have sought to re‐structure the school and develop new ways of working, offers some evaluative comments on this process and considers possible implications of these reforms for other countries. It compares Swedish school reforms with recent English policy developments intended to make ‘extended schools’ a universal provision by 2010.  相似文献   
986.
Political recognition of the parlous state of English social care and the urgent need for radical reform led to calls for new policy approaches that address the two key problems it faced: inadequate funding and poor quality and inappropriate provision. The New Labour government was convinced that it had found a way of dealing with these two competing problems and it embarked on a policy, which has subsequently gained cross-party support. The centre-piece was the concept of a personal budget, and was introduced with a belief that there would be major cost savings while improving service user satisfaction. This article will critically explore the evidence for whether the strategy is fulfilling that promise.  相似文献   
987.
988.
In the changing modern economy some new factors have been addressed that are of importance for productivity and economic growth, such as human skills, workplace organization, information and communication technologies (ICT) and knowledge sharing. An increasing number of companies and organizations are implementing measures to better address these factors, often referred to as 'the New Ways of Working (NWW)'. This consists of a large variety of measures that enable flexibility in the time and location of work. Expectations of these measures are often high, such as a reduction in operating costs and an increase of productivity. However, scientific proof is still lacking, and it is worth asking whether al these implementations actually cause a change in work behavior and effect business outcomes positively. This article describes a case study of three departments (total of 73 employees) that changed from a traditional way of working towards a new way of working. Questionnaires and a new developed objective measurement system called 'work@task' were used to measure changes in work behavior (i.e. increased variation in work location, work times and a change towards NWW management style) and the effect on business objectives such as knowledge sharing, employees satisfaction, and collaboration.  相似文献   
989.
This study offers knowledge about factors associated with a key type of family change, namely, two- to-three-generation household transformations, which are poorly understood, despite increasing numbers of three-generation households, especially ones headed by females. Using a representative sample of 5,874 Australian children, results showed that the circumstances of children in two-generation households differed greatly by family structure. Thus, before investigating determinants of three-generation household formation, children were first grouped as living in either two-parent or single-mother households. For both groups of children, several factors were found associated with three-generation household formation. In two-parent households, the odds of three-generation household formation decreased with mothers?? ages, fathers?? higher educational attainments, and more children, but increased as children grew older. In single-mother households, the odds of three-generation household formation decreased with mothers?? higher educational attainments, increasing income, and more children, but increased if mothers had never been married and worked more hours. Living in rural areas decreased odds of three-generation household formation for children in both types of households. Overall, grandparents appear to play a relatively more important resource role in three-generation, mother only households than in three-generation, two-parent households.  相似文献   
990.
Computer Decision Support Tools (CDSTs) can support clinicians at various stages of the care process and improve healthcare, but implementation of these tools has been difficult. In this study we examine the need for, the use of, and barriers and facilitators to the use of a CDST from a human factor perspective. Results show that there is a need for CDSTs, and that physicians do use well-developed CDSTs. However, there are also barriers against the use, such usability issues and problems fitting them into the clinical workflow.  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