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   236篇
  免费   4篇
管理学   36篇
民族学   1篇
人口学   22篇
理论方法论   18篇
综合类   2篇
社会学   63篇
统计学   98篇
  2023年   5篇
  2022年   1篇
  2021年   3篇
  2020年   9篇
  2019年   18篇
  2018年   16篇
  2017年   21篇
  2016年   14篇
  2015年   9篇
  2014年   8篇
  2013年   51篇
  2012年   7篇
  2011年   9篇
  2010年   7篇
  2009年   1篇
  2008年   2篇
  2007年   7篇
  2006年   8篇
  2005年   5篇
  2004年   2篇
  2003年   6篇
  2002年   2篇
  2001年   2篇
  1999年   3篇
  1998年   5篇
  1997年   1篇
  1996年   1篇
  1994年   1篇
  1993年   2篇
  1992年   2篇
  1991年   2篇
  1989年   3篇
  1988年   1篇
  1987年   2篇
  1986年   1篇
  1979年   1篇
  1974年   1篇
  1969年   1篇
排序方式: 共有240条查询结果,搜索用时 0 毫秒
1.
In this study, the antioxidant enzyme activities such as (SOD, GSH, and CAT) and malondialdehyde (MDA) level which is the end product of lipid peroxidation, were determined from the serum samples taken from patients diagnosed with prostate cancer Van Yuzuncu Y?l University Medical Faculty of Educational Research and Training Hospital and ?stanbul Bagcilar Education Research Hospital. The SOD, GSH, and CAT activity of patient groups was found significantly lower than the healthy control group in patients with prostate cancer (p?相似文献   
2.
Civil war lasting into the 1990s destroyed much of Somalia's economic, political and social structures, and conflict still continues in the southern areas of the country. In 1991, the northwest region declared itself the Independent Republic of Somaliland, established a government in Hargeisa and is struggling to rebuild an infrastructure. It is one of the poorest countries in the world, ranking high on the UN hunger index, and is the third most heavily land-mined country. One of the most disadvantaged groups of people are the disabled, although there is little general information about numbers and kinds of disability, and few social and medical services. This article presents some limited information about the extent of the nature of disability, and local efforts to improve the lives of disabled children and adults. It reports projects funded by non-government organisations, and concentrates on a seminar held in early 2002 attended by a group of disabled people who made their voices heard.  相似文献   
3.
Married individuals are healthier than single individuals though the reasons are not well understood. Individuals with spouses/or partners are less likely to smoke. We explore the relationship between health and marital status by analyzing three potential channels through which marriage affects smoking, i.e., consumption externalities (one spouse's smoking affects the other spouse's welfare), altruism (one spouse reduces smoking in response to the other spouse's bad health), and learning about risks of smoking from the health experience of one's spouse. We find spousal health does not affect smoking due to altruism or learning within the household but do find evidence for consumption externalities.  相似文献   
4.
A general form for characterizing inverse Gaussian and Wald distributions, based on their respective length-biased distributions, is introduced. Further results for characterizations of the gamma distribution, the negative binomial distribution and some mixtures of them by using their lengthbiased distributions are establised.  相似文献   
5.
The author examines developments in marriage patterns in Bangladesh in light of social, cultural, and economic conditions. Previous literature on the subject is used to discuss Muslim marriage, Hindu marriage, child marriage, mate selection and social mobility, and the question of a marriage squeeze. "The analysis presents evidence that the society is experiencing a change in its family formation, mating process and family type. This transition is to some extent towards the characteristics of [the] Western World, but in a poor economy. Part of this transition is due to the effect of modernization and part due to increasing poverty."  相似文献   
6.
Log-location-scale distributions are widely used parametric models that have fundamental importance in both parametric and semiparametric frameworks. The likelihood equations based on a Type II censored sample from location-scale distributions do not provide explicit solutions for the para-meters. Statistical software is widely available and is based on iterative methods (such as, Newton Raphson Algorithm, EM algorithm etc.), which require starting values near the global maximum. There are also many situations that the specialized software does not handle. This paper provides a method for determining explicit estimators for the location and scale parameters by approximating the likelihood function, where the method does not require any starting values. The performance of the proposed approximate method for the Weibull distribution and Log-Logistic distributions is compared with those based on iterative methods through the use of simulation studies for a wide range of sample size and Type II censoring schemes. Here we also examine the probability coverages of the pivotal quantities based on asymptotic normality. In addition, two examples are given.  相似文献   
7.
In this paper, we consider the estimation of the stress–strength parameter R=P(Y<X) when X and Y are independent and both are modified Weibull distributions with the common two shape parameters but different scale parameters. The Markov Chain Monte Carlo sampling method is used for posterior inference of the reliability of the stress–strength model. The maximum-likelihood estimator of R and its asymptotic distribution are obtained. Based on the asymptotic distribution, the confidence interval of R can be obtained using the delta method. We also propose a bootstrap confidence interval of R. The Bayesian estimators with balanced loss function, using informative and non-informative priors, are derived. Different methods and the corresponding confidence intervals are compared using Monte Carlo simulations.  相似文献   
8.
In this article, based on progressively Type-II censored samples from a heterogeneous population that can be represented by a finite mixture of two-component Rayleigh lifetime model, the problem of estimating the parameters and some lifetime parameters (reliability and hazard functions) are considered. Both Bayesian and maximum likelihood estimators are of interest. A class of natural conjugate prior densities is considered in the Bayesian setting. The Bayes estimators are obtained using both the symmetric (squared error) loss function, and the asymmetric (LINEX and General Entropy) loss functions. It has been seen that the estimators obtained can be easily evaluated for this type of censoring by using suitable numerical methods. Finally, the performance of the estimates have been compared on the basis of their simulated maximum square error via a Monte Carlo simulation study.  相似文献   
9.
The purpose of the article is, in case of one sample, to obtain tests concerning the parameter in the power series distribution in one parameter using Ku11back-Leibier information measure. The class of power series distibutions contains a host of discrete distributions. Ve illustrate the general results obtained in case of the geometric distibution.  相似文献   
10.
Using the idea of impirical influence function, Hinkley (1977), the weighted jackknife technique is extended to ratio estimation. A weighted jackknife variance estimator for the ratio estimator is developed. Using the prediction theory approach, the properties of the weighted jackknifed variance estimator are examined. The implications of the failures of regression model on the behaviour of the weighted jackknifed variance estimator, for ratio estimation, are also studied.  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