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   7908篇
  免费   132篇
  国内免费   34篇
管理学   133篇
劳动科学   3篇
民族学   38篇
人才学   2篇
人口学   33篇
丛书文集   871篇
理论方法论   155篇
综合类   5764篇
社会学   388篇
统计学   687篇
  2024年   5篇
  2023年   20篇
  2022年   34篇
  2021年   36篇
  2020年   64篇
  2019年   98篇
  2018年   90篇
  2017年   129篇
  2016年   95篇
  2015年   114篇
  2014年   335篇
  2013年   526篇
  2012年   527篇
  2011年   474篇
  2010年   421篇
  2009年   410篇
  2008年   505篇
  2007年   603篇
  2006年   592篇
  2005年   542篇
  2004年   554篇
  2003年   564篇
  2002年   498篇
  2001年   367篇
  2000年   198篇
  1999年   92篇
  1998年   36篇
  1997年   30篇
  1996年   24篇
  1995年   18篇
  1994年   19篇
  1993年   13篇
  1992年   13篇
  1991年   7篇
  1990年   6篇
  1989年   1篇
  1988年   4篇
  1987年   1篇
  1986年   1篇
  1985年   1篇
  1984年   1篇
  1983年   1篇
  1982年   3篇
  1976年   1篇
  1975年   1篇
排序方式: 共有8074条查询结果,搜索用时 765 毫秒
31.
In risk assessment, the moment‐independent sensitivity analysis (SA) technique for reducing the model uncertainty has attracted a great deal of attention from analysts and practitioners. It aims at measuring the relative importance of an individual input, or a set of inputs, in determining the uncertainty of model output by looking at the entire distribution range of model output. In this article, along the lines of Plischke et al., we point out that the original moment‐independent SA index (also called delta index) can also be interpreted as the dependence measure between model output and input variables, and introduce another moment‐independent SA index (called extended delta index) based on copula. Then, nonparametric methods for estimating the delta and extended delta indices are proposed. Both methods need only a set of samples to compute all the indices; thus, they conquer the problem of the “curse of dimensionality.” At last, an analytical test example, a risk assessment model, and the levelE model are employed for comparing the delta and the extended delta indices and testing the two calculation methods. Results show that the delta and the extended delta indices produce the same importance ranking in these three test examples. It is also shown that these two proposed calculation methods dramatically reduce the computational burden.  相似文献   
32.
For the hierarchical Poisson and gamma model, we calculate the Bayes posterior estimator of the parameter of the Poisson distribution under Stein's loss function which penalizes gross overestimation and gross underestimation equally and the corresponding Posterior Expected Stein's Loss (PESL). We also obtain the Bayes posterior estimator of the parameter under the squared error loss and the corresponding PESL. Moreover, we obtain the empirical Bayes estimators of the parameter of the Poisson distribution with a conjugate gamma prior by two methods. In numerical simulations, we have illustrated: The two inequalities of the Bayes posterior estimators and the PESLs; the moment estimators and the Maximum Likelihood Estimators (MLEs) are consistent estimators of the hyperparameters; the goodness-of-fit of the model to the simulated data. The numerical results indicate that the MLEs are better than the moment estimators when estimating the hyperparameters. Finally, we exploit the attendance data on 314 high school juniors from two urban high schools to illustrate our theoretical studies.  相似文献   
33.
Objective: This study aims to investigate the effect of smoking on sexual functions in AS patients.

Patients and methods: A total of 67 male AS patients with a median age of 34 years (range: 18–57) reporting sexual activity at least for the past 4 weeks period were included. Patients were divided into smokers (Group 1, n?=?47) and non-smokers (Group 2, n?=?20). Fagerström test for nicotine dependence, smoking history, exhaled carbon monoxide test were recorded for smoking AS patients. Visual analogue scale (VAS), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Metrology Index (BASMI), Bath Ankylosing Spondylitis Functional Index (BASFI), Ankylosing Spondylitis Quality of Life (ASQoL), International Index of Erectile Function (IIEF), Beck Depression Inventory (BDI) were filled for both groups.

Results: There was no significant difference between smokers and non-smokers in all evaluation parameters. BASMI scores were significantly lower in the mild dependency subgroup as compared to those with moderate or severe dependency (p?=?.005 and p?=?.007, respectively). Total IIEF score and IIEF categories correlated significantly with BASDAI, BASFI, BASMI, ASQoL, pain, fatigue, and cumulative smoking. BDI showed an inverse correlation with the IIEF score and IIEF category (p?r?=?–0.520, p?r?=?–0.508, respectively).

Conclusions: Sexual function in AS patients is associated with the pain, fatigue, disease activity, functional status, quality of life, depression as well as the cumulative exposure to smoking, and that sexual functions tend to decline with increasing degree of cigarette dependency.  相似文献   
34.
35.
Abstract

On the basis of Wang and Cheng (J. Math. Anal. Appl. 384 (2011) 597–606), this paper further investigates elementary renewal theorems for counting processes generated by random walks with widely orthant dependent increments. The obtained results improve the corresponding ones of the above-mentioned paper mainly in the sense of weakening the moment conditions on the positive parts of the increments. Meanwhile, a revised version of strong law of large numbers for random walks with widely orthant dependent increments is established, which improves Theorem 1.4 of Wang and Cheng (2011 Wang, Y., and D. Cheng. 2011. Basic renewal theorems for a random walk with widely dependent increments and their applications. Journal of Mathematical Analysis and Applications 384 (2):597606. doi:10.1016/j.jmaa.2011.06.010.[Crossref], [Web of Science ®] [Google Scholar]) by enlarging the regions of dominating coefficients. Finally, by using the above results, some precise large deviation results for a nonstandard renewal risk model are established, in which the innovations are widely orthant dependent random variables with common heavy tails, and the inter-arrival times are also widely orthant dependent.  相似文献   
36.
37.
本科院校发展高职教育应从更新教育观念,狠抓基本建设和深化教育教学改革等方面进行。  相似文献   
38.
成人高等教育教学管理模式改革的思考   总被引:2,自引:0,他引:2  
目前成人高等教育在教学管理中仍然存在许多不足,结合我院成人学生教学管理所取得的成绩和经验,针对当前所面临的现状和问题,指出应进一步深化成人学生教学管理模式改革,并提出了相应的对策措施。  相似文献   
39.
构建高职院校校园安全文化体系的思考   总被引:1,自引:0,他引:1  
本文论述高职院校校园安全文化体系建设的构想以及实现途径。  相似文献   
40.
Since the 1980s outsourcing has been a major topic in both economic and management literature. Economic literature tends to focus on the transaction cost perspective. In management literature the core competence approach prevails. An emerging alternative view on outsourcing is the power and dependence perspective. Aspects of power and dependence become visible in four case studies involving the maintenance of capital assets. In each instance both the buyer and supplier sides of the dyad are examined. The paper concludes with managerial implications and research opportunities.  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