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   11505篇
  免费   331篇
  国内免费   3篇
管理学   1710篇
民族学   68篇
人才学   15篇
人口学   997篇
丛书文集   61篇
理论方法论   1232篇
综合类   113篇
社会学   5665篇
统计学   1978篇
  2023年   67篇
  2021年   81篇
  2020年   182篇
  2019年   266篇
  2018年   306篇
  2017年   371篇
  2016年   309篇
  2015年   217篇
  2014年   261篇
  2013年   1877篇
  2012年   412篇
  2011年   378篇
  2010年   291篇
  2009年   255篇
  2008年   300篇
  2007年   341篇
  2006年   310篇
  2005年   340篇
  2004年   307篇
  2003年   250篇
  2002年   278篇
  2001年   246篇
  2000年   251篇
  1999年   241篇
  1998年   207篇
  1997年   203篇
  1996年   168篇
  1995年   158篇
  1994年   197篇
  1993年   166篇
  1992年   184篇
  1991年   137篇
  1990年   138篇
  1989年   134篇
  1988年   154篇
  1987年   133篇
  1986年   121篇
  1985年   140篇
  1984年   135篇
  1983年   125篇
  1982年   121篇
  1981年   110篇
  1980年   104篇
  1979年   113篇
  1978年   90篇
  1977年   80篇
  1976年   102篇
  1975年   79篇
  1974年   68篇
  1973年   57篇
排序方式: 共有10000条查询结果,搜索用时 578 毫秒
51.
52.
To capture mean and variance asymmetries and time‐varying volatility in financial time series, we generalize the threshold stochastic volatility (THSV) model and incorporate a heavy‐tailed error distribution. Unlike existing stochastic volatility models, this model simultaneously accounts for uncertainty in the unobserved threshold value and in the time‐delay parameter. Self‐exciting and exogenous threshold variables are considered to investigate the impact of a number of market news variables on volatility changes. Adopting a Bayesian approach, we use Markov chain Monte Carlo methods to estimate all unknown parameters and latent variables. A simulation experiment demonstrates good estimation performance for reasonable sample sizes. In a study of two international financial market indices, we consider two variants of the generalized THSV model, with US market news as the threshold variable. Finally, we compare models using Bayesian forecasting in a value‐at‐risk (VaR) study. The results show that our proposed model can generate more accurate VaR forecasts than can standard models.  相似文献   
53.
Oiler, Gomez & Calle (2004) give a constant sum condition for processes that generate interval‐censored lifetime data. They show that in models satisfying this condition, it is possible to estimate non‐parametrically the lifetime distribution based on a well‐known simplified likelihood. The author shows that this constant‐sum condition is equivalent to the existence of an observation process that is independent of lifetimes and which gives the same probability distribution for the observed data as the underlying true process.  相似文献   
54.
Not having a variance estimator is a seriously weak point of a sampling design from a practical perspective. This paper provides unbiased variance estimators for several sampling designs based on inverse sampling, both with and without an adaptive component. It proposes a new design, which is called the general inverse sampling design, that avoids sampling an infeasibly large number of units. The paper provide estimators for this design as well as its adaptive modification. A simple artificial example is used to demonstrate the computations. The adaptive and non‐adaptive designs are compared using simulations based on real data sets. The results indicate that, for appropriate populations, the adaptive version can have a substantial variance reduction compared with the non‐adaptive version. Also, adaptive general inverse sampling with a limitation on the initial sample size has a greater variance reduction than without the limitation.  相似文献   
55.
The author traces the development of the Milan approach from the beginning, through the split into two teams in 1980, and subsequent developments in theory and application. He identifies possible unrecognised or undeclared influences of Milan in other family therapy approaches.  相似文献   
56.
Disabled people are excluded in various ways from a wide range of social privileges, activities and institutions. Voluntary and charitable organisations promote themselves as champions of disabled people in their struggle for access to the ordinary choices and opportunities of everyday life. This paper reports the findings of an empirical study which demonstrate that in voluntary agencies governed by able-bodied people, disabled people are excluded from positions of power and influence, and they experience the same sorts of barriers and constraints as those with which they are confronted in the wider world. Furthermore, the development of agencies governed by disabled people themselves is constrained by their lack of access to money, staff and other resources.  相似文献   
57.
58.
Because of the close connection between culture and language, a number of writers have suggested that bilinguals will differ in their behavior because of differences in the degree of assimilation of different cultures in the same individual. We tested this notion by obtaining data from bilingual (English and Hindi) college students in India using a well-studied cross-cultural research paradigm involving emotional perception. Subjects judged universal facial expressions of emotion in two separate sessions, one conducted entirely in English, the other in Hindi. In each session, they judged which emotion was being portrayed, and how intensely. Subjects recognized anger, fear, and sadness more accurately in English than in Hindi. They also attributed greater intensity to female photos of anger when rating in Hindi, but attributed greater intensity to female photos of sadness when rating in English. These findings were discussed in relation to the theoretical connection between culture and language.  相似文献   
59.
Vulnerability and Agenda: Context and Process in Project Management   总被引:1,自引:0,他引:1  
This paper explores how the project management role is conditioned by the context in which change is progressed. The argument draws on Pettigrew's (1985, 1987) contextual and processual view of change, a view which does not clarify the management implications of contextual variation. Using data from a two-stage research design combining diary and survey methods, four context dimensions are identified, concerning ‘interlocking’, ‘shifting sands’, ‘ownership’ and ‘senior management view’. For analytical purposes, two extreme contexts are characterized as exposing the project manager to high and low levels of ‘vulnerability’ respectively. Project management literature typically offers a rational-linear account of change, and concentrates on ‘content’ and ‘control’ agendas, concerning technical expertise on the one hand, and planning, budgeting and monitoring techniques on the other. Sociological analyses reveal the limitations of the rational-linear account, and focus on the political and cultural dimensions of the ‘process’ agenda. The data suggest how contextual variation affects the relative priority of these agendas. The management implications of these findings are explored, for project management selection, career progression, and the development of diagnostic skills and ‘agenda management’ strategies.  相似文献   
60.
Recent studies have shown that group differences in marital stability and satisfaction can be predicted based on premarital relationship quality. There is also a growing literature indicating that there are distinct types of relationships, both premaritally and developmentally over time. This study examined the relationship between the four premarital types (Vitalized, Harmonious, Traditional, and Conflicted) identified by Fowers and Olson (1992) and relationship outcome over a 3-year period with 393 couples. A substantial relationship was found, with conflicted couples being the most likely to separate or divorce. Vitalized couples had the highest levels of satisfaction, followed by Harmonious, Traditional, and Conflicted couples. Traditional couples were less likely to have divorced than Harmonious couples, even though Harmonious couples had higher premarital relationship satisfaction scores.  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