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   539篇
  免费   18篇
管理学   61篇
民族学   2篇
人口学   36篇
丛书文集   3篇
理论方法论   64篇
综合类   11篇
社会学   182篇
统计学   198篇
  2023年   4篇
  2022年   1篇
  2021年   8篇
  2020年   19篇
  2019年   24篇
  2018年   39篇
  2017年   30篇
  2016年   28篇
  2015年   9篇
  2014年   14篇
  2013年   139篇
  2012年   28篇
  2011年   21篇
  2010年   26篇
  2009年   23篇
  2008年   19篇
  2007年   18篇
  2006年   14篇
  2005年   6篇
  2004年   10篇
  2003年   8篇
  2002年   2篇
  2001年   8篇
  2000年   6篇
  1999年   5篇
  1998年   6篇
  1997年   5篇
  1996年   4篇
  1995年   1篇
  1994年   2篇
  1993年   1篇
  1992年   5篇
  1991年   3篇
  1990年   3篇
  1989年   2篇
  1988年   1篇
  1986年   1篇
  1985年   2篇
  1984年   2篇
  1983年   4篇
  1981年   2篇
  1978年   1篇
  1976年   1篇
  1975年   1篇
  1972年   1篇
排序方式: 共有557条查询结果,搜索用时 15 毫秒
41.
Objective: The objective of this study is to investigate the impact of metabolic status on associations of serum vitamin D with hypogonadism and lower urinary tract symptoms (LUTS)/benign prostatic hyperplasia (BPH).

Patients and methods: A total of 612 men underwent physical examination, biochemical/hormonal blood testing, and transrectal prostate ultrasound. Moreover, the subjects filled out standard questionnaires for identification and grading of LUTS and hypogonadism symptoms. Parameters were statistically compared with independent t-tests and correlation analyses.

Results: Vitamin D levels positively correlated with total testosterone (TT) but not with prostate volume or International Prostate Symptom Score (IPSS). Patients with metabolic syndrome had significantly lower vitamin D levels, which were not correlated with TT, prostate volume, or IPSS. However, vitamin D was positively correlated with TT, and negatively correlated with prostate volume and quality-of-life IPSS in subjects without metabolic syndrome.

Conclusion: The clinical usefulness of vitamin D for treatment of hypogonadism or LUTS/BPH varies according to metabolic status.  相似文献   

42.
43.
An integrated process control (IPC) procedure is a scheme which combines the engineering process control (EPC) and the statistical process control (SPC) procedures for the process where the noise and a special cause are present. The most efficient way of reducing the effect of the noise is to adjust the process by its forecast, which is done by the EPC procedure. The special cause, which produces significant deviations of the process level from the target, can be detected by the monitoring scheme, which is done by the SPC procedure. The effects of special causes can be eliminated by a rectifying action. The performance of the IPC procedure is evaluated in terms of the average run length (ARL) or the expected cost per unit time (ECU). In designing the IPC procedure for practical use, it is essential to derive its properties constituting the ARL or ECU based on the proposed process model. The process is usually assumed as it starts only with noise, and special causes occur at random times afterwards. The special cause is assumed to change the mean as well as all the parameters of the in-control model. The linear filter models for the process level as well as the controller and the observed deviations for the IPC procedure are developed here.  相似文献   
44.
This study analyses weblog abortion-related content sampled via a search and snowball method. When weblogs located inside of established media Web sites and other weblogs are compared, they are equivalent in the use of advocacy versus objectivist frames. Media weblog posts contain a political frame more frequently than non-media weblog posts do. In terms of diversity of frame, media weblogs employ more frames in their stories. Various explanations for these findings are offered in the context of current abortion-related content patterns.  相似文献   
45.
We implement a field experiment with hotel guests to measure the effects of nonprice interventions on water conservation and customer satisfaction. In hotels, guests have no direct pecuniary incentive to conserve water, as consumers do at home, where they pay their own water bills. Because hotels earn greater profits when they manage to convince guests to conserve, guests may be suspicious of a hotel's stated social goal of water conservation. By implementing behavioral interventions that address these challenges, we find that our nudges can induce guests to reduce their water consumption, even when no direct monetary incentive is provided. Using post‐stay customer surveys, we detected no adverse effects on customer satisfaction due to these nudges. (JEL D12, I31, Q41, Q50)  相似文献   
46.
47.
Hee Won Kang  Sung Joo Park 《Omega》1983,11(2):147-153
An optimum expansion of a single capacity is considered when the installation cost is very large and future demand is given by an evolving process of Wiener. Risk of expansion is evaluated and included in the decision criteria which links the capacity expansion problem with financial investment theory, Numerical results show the existence of an optimum expansion capacity and an efficient curve which represent the optimum choices with respect to the possible combinations of expansion cost and risk.  相似文献   
48.
This article describes and highlights the potential contributions that the constructs multifinality, work hope, and possible selves make for designing career counseling interventions and for better understanding possible career‐related factors associated with academic engagement and achievement among urban minority youth. Multifinality may serve as a superordinate orientation because it conceptualizes development as discontinuous and relatively plastic, allowing for youth deemed at risk to follow more hopeful pathways. Work hope and possible selves emphasize the utility of providing urban minority youth with space to answer questions related to what they might achieve and do in the future and who they might become. Together, multifinality, work hope, and possible selves provide a hopeful conceptual framework for career researchers and practitioners.  相似文献   
49.
Richard Schoenherr, professor of sociology at the University of Wisconsin — Madison, passed away unexpectedly on 9 January 1996. He is memorialized in this essay for his scholarly contributions in the areas of teaching, research, and service.  相似文献   
50.
The Kulback-Leibler information has been considered for establishing goodness-of-fit test statistics, which have been shown to perform very well (Arizono & Ohta, 1989; Ebrahimi et al., 1992, etc). In this paper, we propose censored Kullback-Leibler information to generalize the discussion of the Kullback-Leibler information to the censored case. Then we establish a goodness-of-fit test statistic based on the censored Kullback-Leibler information with the type 2 censored data, and compare the test statistics with some existing test statistics for the exponential and normal distributions.  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