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   1618篇
  免费   33篇
  国内免费   7篇
管理学   38篇
劳动科学   1篇
民族学   8篇
人口学   8篇
丛书文集   125篇
理论方法论   48篇
综合类   821篇
社会学   37篇
统计学   572篇
  2024年   1篇
  2023年   3篇
  2022年   2篇
  2021年   9篇
  2020年   11篇
  2019年   21篇
  2018年   19篇
  2017年   37篇
  2016年   27篇
  2015年   35篇
  2014年   51篇
  2013年   273篇
  2012年   85篇
  2011年   82篇
  2010年   76篇
  2009年   81篇
  2008年   83篇
  2007年   105篇
  2006年   84篇
  2005年   102篇
  2004年   84篇
  2003年   71篇
  2002年   61篇
  2001年   78篇
  2000年   43篇
  1999年   29篇
  1998年   16篇
  1997年   9篇
  1996年   10篇
  1995年   10篇
  1994年   11篇
  1993年   6篇
  1992年   5篇
  1991年   6篇
  1990年   4篇
  1989年   2篇
  1988年   7篇
  1987年   2篇
  1986年   2篇
  1985年   4篇
  1984年   1篇
  1983年   2篇
  1982年   2篇
  1978年   1篇
  1977年   2篇
  1976年   1篇
  1975年   2篇
排序方式: 共有1658条查询结果,搜索用时 643 毫秒
21.
儒家思想在中华文化中占有突出的位置,发挥着弥散性功能,渗透到中国古代社会生活的各个领域各个层次各个方面。扫描儒家思想,可见其问题、理念、范式与时俱进;对其进行结构探悉,发现其主旨、论域、关怀一如既往;对其进行功能考量,得知其学术、治术、心术功能兼容并包。  相似文献   
22.
Dynamic reliability models with conditional proportional hazards   总被引:1,自引:0,他引:1  
A dynamic approach to the stochastic modelling of reliability systems is further explored. This modelling approach is particularly appropriate for load-sharing, software reliability, and multivariate failure-time models, where component failure characteristics are affected by their degree of use, amount of load, or extent of stresses experienced. This approach incorporates the intuitive notion that when a set of components in a coherent system fail at a certain time, there is a jump from one structure function to another which governs the residual lifetimes of the remaining functioning components, and since the component lifetimes are intrinsically affected by the structure function which they constitute, then at such a failure time there should also be a jump in the stochastic structure of the lifetimes of the remaining components. For such dynamically-modelled systems, the stochastic characteristics of their jump times are studied. These properties of the jump times allow us to obtain the properties of the lifetime of the system. In particular, for a Markov dynamic model, specific expressions for the exact distribution functions of the jump times are obtained for a general coherent system, a parallel system, and a series-parallel system. We derive a new family of distribution functions which describes the distributions of the jump times for a dynamically-modelled system.  相似文献   
23.
Sample selection in radiocarbon dating   总被引:1,自引:0,他引:1  
Archaeologists working on the island of O'ahu, Hawai'i, use radiocarbon dating of samples of organic matter found trapped in fish-pond sediments to help them to learn about the chronology of the construction and use of the aquicultural systems created by the Polynesians. At one particular site, Loko Kuwili, 25 organic samples were obtained and funds were available to date an initial nine. However, on calibration to the calendar scale, the radiocarbon determinations provided date estimates that had very large variances. As a result, major issues of chronology remained unresolved and the archaeologists were faced with the prospect of another expensive programme of radiocarbon dating. This paper presents results of research that tackles the problems associated with selecting samples from those which are still available. Building on considerable recent research that utilizes Markov chain Monte Carlo methods to aid archaeologists in their radiocarbon calibration and interpretation, we adopt the standard Bayesian framework of risk functions, which allows us to assess the optimal samples to be sent for dating. Although rather computer intensive, our algorithms are simple to implement within the Bayesian radiocarbon framework that is already in place and produce results that are capable of direct interpretation by the archaeologists. By dating just three more samples from Loko Kuwili the expected variance on the date of greatest interest could be substantially reduced.  相似文献   
24.
The matching identification problem (MIP) is a combinatoric search problem related to the fields of learning from examples, boolean functions, and knowledge acquisition. The MIP involves identifying a single “goal” item from a large set of items. Because there is commonly a cost associated with evaluating each guess, the goal item should be identified in as few guesses as possible. As in most search problems, the items have a similar structure, which allows an evaluation of each guessed item. In other words, each guessed item elicits partial information about the goal item, i.e. how similar the guess is to the goal. With this information the goal is more quickly identified.The unordered MIP has been studied by Mehrez and Steinberg (ORSA J. Comput. 7 (1995) 211) in which they proposed two different types of algorithms. The purpose of the present paper is to suggest an improved Spanning Heuristic algorithm. Its improvement increases as the problem size increases. Further results and comparisons are derived for the unordered and ordered cases.This research shows that when the search space is very large, it is better to inquire from items that are known not to be the goal (they have been ruled out by previous guesses), for the purpose of acquiring more information about the goal. As the search space is narrowed, it is better to guess items that have not been ruled out.  相似文献   
25.
政府审计是对权力的监督和制约,现阶段,我国地方政府审计面临的发展困境主要是审计职能软化问题,针对地方政府审计存在的主要问题,剖析原因,从多角度提出解决审计职能软化的对策。  相似文献   
26.
《Journal of homosexuality》2012,59(10):1274-1302
This study used a correlational design with a sample of university students to clarify the relationships between attitude functions and homonegativity with respect to gender. Classic work on attitude functions posits that attitudes serve psychological needs for the attitude holder. Herek (1986b) adapted this theory to explain attitudes toward homosexuality. Herek (1987) identified four functions: ego-defensive (defense of threats to the self), value-expressive (expression of key values), social-expressive (expression of important social norms), and experiential (based on past experiences). Results suggested that men were more likely to attribute their attitudes to the ego-defensive function. Men and women were equally likely to attribute their attitudes to the experiential function. The ego-defensive function was the best predictor of homonegativity for men and women, whether they held generally positive or generally negative attitudes toward homosexuality. The experiential function did not predict homonegativity. Participants tended to be neither very homonegative nor very ego-defensive.  相似文献   
27.
In this article, we propose a general class of partially linear transformation models for recurrent gap time data, which extends the linear transformation models by incorporating non linear covariate effects and includes the partially linear proportional hazards and the partially linear proportional odds models as special cases. Both global and local estimating equations are developed to estimate the parametric and non parametric covariate effects, and the asymptotic properties of the resulting estimators are established. The finite-sample behavior of the proposed estimators is evaluated through simulation studies, and an application to a clinic study on chronic granulomatous disease is provided.  相似文献   
28.
The purpose of this study was to provide a more comprehensive understanding of the relation between early parent‐child interactions and subsequent behavior problems and how certain cognitive processes mediate this relation. Specifically, this study investigated whether attention, inhibition, and planning skills mediate the relation between attachment security and behavior problems. Data were collected as part of the National Institute of Child Health and Development‐Study of Early Child Care and Youth Development when children (N = 1004) were between 36 months and the third grade. Results from structural equation models indicated that sustained attention mediated the relation between disorganized attachment and social problems. Planning mediated the relation between disorganized attachment and subsequent thought problems, attention problems, and delinquent behavior. Avoidant, ambivalent, and disorganized attachment directly predicted several behavior problems. Implications for theory and future research are discussed.  相似文献   
29.
A procedure is proposed for testing the equality of k dependent correlation coefficients. The procedure is simulated utilizing Monte Carlo techniques; and, a method for post hoc probing is also suggested.  相似文献   
30.
The receiver operating characteristic (ROC) curve is one of the most commonly used methods to compare the diagnostic performance of two or more laboratory or diagnostic tests. In this paper, we propose semi-empirical likelihood based confidence intervals for ROC curves of two populations, where one population is parametric and the other one is non-parametric and both have missing data. After imputing missing values, we derive the semi-empirical likelihood ratio statistic and the corresponding likelihood equations. It is shown that the log-semi-empirical likelihood ratio statistic is asymptotically scaled chi-squared. The estimating equations are solved simultaneously to obtain the estimated lower and upper bounds of semi-empirical likelihood confidence intervals. We conduct extensive simulation studies to evaluate the finite sample performance of the proposed empirical likelihood confidence intervals with various sample sizes and different missing probabilities.  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