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   796篇
  免费   29篇
管理学   165篇
民族学   6篇
人口学   40篇
丛书文集   1篇
理论方法论   92篇
综合类   6篇
社会学   399篇
统计学   116篇
  2023年   8篇
  2022年   8篇
  2021年   8篇
  2020年   21篇
  2019年   49篇
  2018年   22篇
  2017年   39篇
  2016年   33篇
  2015年   27篇
  2014年   39篇
  2013年   74篇
  2012年   43篇
  2011年   35篇
  2010年   40篇
  2009年   22篇
  2008年   37篇
  2007年   47篇
  2006年   31篇
  2005年   34篇
  2004年   28篇
  2003年   33篇
  2002年   19篇
  2001年   17篇
  2000年   10篇
  1999年   7篇
  1998年   9篇
  1997年   3篇
  1996年   5篇
  1995年   2篇
  1994年   8篇
  1993年   2篇
  1992年   5篇
  1991年   6篇
  1990年   4篇
  1989年   4篇
  1988年   5篇
  1987年   6篇
  1986年   4篇
  1985年   3篇
  1984年   5篇
  1983年   4篇
  1981年   2篇
  1980年   6篇
  1979年   2篇
  1978年   1篇
  1977年   1篇
  1976年   2篇
  1972年   1篇
  1971年   2篇
  1967年   1篇
排序方式: 共有825条查询结果,搜索用时 15 毫秒
771.
This work examined predictions of the interpolation of familiar views (IFV) account of object recognition performance in 5‐month‐olds. Infants were familiarized to an object either from a single viewpoint or from multiple viewpoints varying in rotation around a single axis. Object recognition was then tested in both conditions with the same object rotated around a novel axis. Infants in the multiple‐views condition recognized the object, whereas infants in the single‐view condition provided no evidence for recognition. Under the same 2 familiarization conditions, infants in a 2nd experiment treated as novel an object that differed in only 1 component from the familiar object. Infants' object recognition is enhanced by experience with multiple views, even when that experience is around an orthogonal axis of rotation, and infants are sensitive to even subtle shape differences between components of similar objects. In general, infants' performance does not accord with the predictions of the IFV model of object recognition. These findings motivate the extension of future research and theory beyond the limits of strictly interpolative mechanisms.  相似文献   
772.
The authors consider time series observations with data irregularities such as censoring due to a detection limit. Practitioners commonly disregard censored data cases which often result in biased estimates. The authors present an attractive remedy for handling autocorrelated censored data based on a class of autoregressive and moving average (ARMA) models. In particular, they introduce an imputation method well suited for fitting ARMA models in the presence of censored data. They demonstrate the effectiveness of their technique in terms of bias, efficiency, and information loss. They also describe its adaptation to a specific context of meteorological time series data on cloud ceiling height, which are measured subject to the detection limit of the recording device.  相似文献   
773.
774.
Markowitz (Journal of Political Economy 60:151–158, 1952) identified a fourfold pattern of risk preferences in outcome magnitude: When outcomes are large, people are risk averse in gains and risk seeking in losses, but risk preferences reverse when the outcomes are small, with people exhibiting risk seeking in gains and risk aversion in losses. This fourfold pattern was not addressed by either version of prospect theory (Kahneman and Tversky Econometrica 47:363–391, 1979; Tversky and Kahneman Journal of Risk and Uncertainty 5:297–323, 1992). We show how prospect theory can accommodate the pattern by combining an overweighting of low probabilities with a decreasingly elastic value function. We then examine the performance of prospect theory with two decreasingly elastic value functions: Prospect theory performs better, both quantitatively and qualitatively, with a normalized logarithmic value function than with a normalized exponential value function. We discuss several issues, and speculate about why Tversky and Kahneman did not address Markowitz’s fourfold pattern.  相似文献   
775.
The property of an allocation rule to be implementable in dominant strategies by a unique payment scheme is called revenue equivalence. We give a characterization of revenue equivalence based on a graph theoretic interpretation of the incentive compatibility constraints. The characterization holds for any (possibly infinite) outcome space and many of the known results are immediate consequences. Moreover, revenue equivalence can be identified in cases where existing theorems are silent.  相似文献   
776.
White and racial minorities with equal qualifications applied simultaneously for 43 waiter/waitress jobs in New York City fine dining restaurants. Applicants of all demographic backgrounds were treated with equal courtesy, but minorities were only 54% as likely as whites to receive a job offer. This discrimination, either conscious or unconscious, was documented in 31% of restaurants tested. Post-hiring differences appear even more widespread, with front of the house minority restaurant servers averaging 12% lower earnings than their equally qualified white peers. Ensuring equal treatment in hiring would expand minority access to good jobs in Manhattan fine dining by 3500 positions but not make it universal.  相似文献   
777.
Sargent et al (J Clin Oncol 23: 8664–8670, 2005) concluded that 3-year disease-free survival (DFS) can be considered a valid surrogate (replacement) endpoint for 5-year overall survival (OS) in clinical trials of adjuvant chemotherapy for colorectal cancer. We address the question whether the conclusion holds for trials involving other classes of treatments than those considered by Sargent et al. Additionally, we assess if the 3-year cutpoint is an optimal one. To this aim, we investigate whether the results reported by Sargent et al. could have been used to predict treatment effects in three centrally randomized adjuvant colorectal cancer trials performed by the Japanese Foundation for Multidisciplinary Treatment for Cancer (JFMTC) (Sakamoto et al. J Clin Oncol 22:484–492, 2004). Our analysis supports the conclusion of Sargent et al. and shows that using DFS at 2 or 3 years would be the best option for the prediction of OS at 5 years.  相似文献   
778.
779.
The author discusses a recent paper published in Science (see Arantes-Oliveira) that shows that germline stem cells in the worm Caenorhabditis elegans send a signal to a steroid hormone receptor and a forkhead-family member to stimulate reproduction and shorten longevity. The author compares the new results to previous findings in the fruit fly and discusses possible mechanisms behind the inverse relationship between reproduction and life-span extension.  相似文献   
780.
This article considers inter‐individual variation in omission rates of the preverbal particle ne in 991 negations produced in conversations between 73 native and non‐native speakers of French. It appears that both endogenous and exogenous extralinguistic factors are linked to omission rates of ne . Whereas age and gender were found to have little effect, the degree of extraversion of the speaker, the frequency of use of French and the native/non‐native status of the speakers were correlated with omission rates. Among the exogenous factors it appeared that the composition of the dyad was linked to omission rates: non‐native speakers interacting with native speakers omitted the ne more frequently than the non‐native speakers in conversation with other non‐native speakers. The theoretical implications of these findings are discussed.  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