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   3426篇
  免费   121篇
  国内免费   39篇
管理学   285篇
劳动科学   2篇
民族学   18篇
人口学   178篇
丛书文集   171篇
理论方法论   119篇
综合类   1628篇
社会学   75篇
统计学   1110篇
  2024年   2篇
  2023年   14篇
  2022年   27篇
  2021年   35篇
  2020年   70篇
  2019年   63篇
  2018年   98篇
  2017年   131篇
  2016年   96篇
  2015年   81篇
  2014年   159篇
  2013年   461篇
  2012年   236篇
  2011年   216篇
  2010年   163篇
  2009年   174篇
  2008年   209篇
  2007年   211篇
  2006年   186篇
  2005年   192篇
  2004年   132篇
  2003年   127篇
  2002年   113篇
  2001年   90篇
  2000年   62篇
  1999年   43篇
  1998年   32篇
  1997年   35篇
  1996年   23篇
  1995年   28篇
  1994年   12篇
  1993年   11篇
  1992年   11篇
  1991年   13篇
  1990年   8篇
  1989年   4篇
  1988年   5篇
  1987年   2篇
  1986年   2篇
  1985年   1篇
  1984年   3篇
  1982年   4篇
  1979年   1篇
排序方式: 共有3586条查询结果,搜索用时 15 毫秒
71.
Maryam Esna-Ashari 《Statistics》2016,50(6):1421-1433
In survival analysis and reliability theory, a fundamental problem is the study of lifetime properties of a live organism or system. In this regard, there have been considered and studied several models based on different concepts of ageing such as hazard rate and mean residual life. In this paper, we consider an additive-multiplicative hazard model (AMHM) and study some reliability and ageing properties of the proposed model. We then specify the bivariate models whose conditionals satisfy AMHM. Several properties of the proposed bivariate model are investigated and adequacy of the model is evaluated based on a real data set.  相似文献   
72.
Motivated by the need to analyze the National Longitudinal Surveys data, we propose a new semiparametric longitudinal mean‐covariance model in which the effects on dependent variable of some explanatory variables are linear and others are non‐linear, while the within‐subject correlations are modelled by a non‐stationary autoregressive error structure. We develop an estimation machinery based on least squares technique by approximating non‐parametric functions via B‐spline expansions and establish the asymptotic normality of parametric estimators as well as the rate of convergence for the non‐parametric estimators. We further advocate a new model selection strategy in the varying‐coefficient model framework, for distinguishing whether a component is significant and subsequently whether it is linear or non‐linear. Besides, the proposed method can also be employed for identifying the true order of lagged terms consistently. Monte Carlo studies are conducted to examine the finite sample performance of our approach, and an application of real data is also illustrated.  相似文献   
73.
This article examined the theoretical meanings of pension rights and analyzed their effects on women's economic risks in developed countries. First, based on the status of a citizen, worker, parent, and spouse, this study investigated how pension benefits are guaranteed as a citizen regardless of work history, the degree to which women's disadvantageous situations in the labor market and unpaid work are compensated by public pension as workers and parents, and how marital status is treated in the different pension systems. Second, analysis of the effect of pension rights showed that individual rights is a significant factor to prevent economic risks of elderly women. Derived rights did not seem to secure the economic welfare of elderly women, at least in a comparative context. This finding suggested that developing individual rights, rather than derived rights, is the way to guarantee long‐term elderly women's economic welfare.  相似文献   
74.
韦森 《科学发展》2014,(2):26-29
从经济的投资、消费和出口数据看,中国经济增速确实在下行。为了保持中国经济8%的增速,我们已付出了很高的代价;经过35年的高速增长,在各行各业产能基本过剩的情况下,中国经济增速正在下移。观察1950年代后日本、中国台湾和香港地区经济发展的过程,其经济高速增长后,也是一个台阶又一个台阶地下来。中国不能再靠高投资来推动经济增长。  相似文献   
75.
76.
Abstract

In this paper we find the maximum likelihood estimates (MLEs) of hazard rate and mean residual life functions (MRLF) of Pareto distribution, their asymptotic non degenerate distribution, exact distribution and moments. We also discuss the uniformly minimum variance unbiased estimate (UMVUE) of hazard rate function and MRLF. Finally, two numerical examples with simulated data and real data set, are presented to illustrate the proposed estimates.  相似文献   
77.
肇始于希腊的欧洲债务危机到目前为止都没有停息的迹象,甚至还呈蔓延之势。欧洲债务危机爆发的直接原因是在金融危机的背景下,政府支出规模持续扩大,导致财政赤字居高不下,最终使得国债规模超过政府的偿还能力,出现明显的违约可能性。同时,国际竞争力不足,导致出口受阻,使得资金问题更加严重。从更深层次看,产业结构不合理,经济发展速度缓慢,过低的投资率和储蓄率及过高的储蓄投资转化率,都是导致欧债危机的重要原因。  相似文献   
78.
Methods for a sequential test of a dose-response effect in pre-clinical studies are investigated. The objective of the test procedure is to compare several dose groups with a zero-dose control. The sequential testing is conducted within a closed family of one-sided tests. The procedures investigated are based on a monotonicity assumption. These closed procedures strongly control the familywise error rate while providing information about the shape of the dose-responce relationship. Performance of sequential testing procedures are compared via a Monte Carlo simulation study. We illustrae the procedures by application to a real data set.  相似文献   
79.
This paper describes the findings of a survey of 1109 lesbians who attended the Women's Music Festival held in Michigan in carly August 1985. The primary objectives of the study were to document the incidence of domestic violence in a non-random sample of lesbian relationships; to identify and describe the types of domestic violence experienced and/or perpetrated; and to ascertain thc availability and accessibility of community helping resources to survivors and perpetrators after an abusive episode. Comparisons with domestic violence in heterosexual relationships are also made, followed by a discussion on the research and practice implications of the findings.  相似文献   
80.
在气藏水平井中随着生产管柱倾斜角度的变化,井筒内液体的重力作用会发生改变,从而引起气液两相流型的变化。以产气为主的气井井筒内液体主要以液膜、液滴的形式出现,由此出现了液滴模型与液膜模型两种解释积液的理论。从这两种携液理论出发,考虑生产管柱倾斜角度的影响,对倾斜管内液滴、液膜进行受力分析,推导出了随管柱倾斜角度变化的连续携液临界流速的计算式,使之适用于水平井连续携液临界流量的计算。设计制作了水平气井连续携液实验装置并进行了实验研究,观测气藏水平井中气水两相运动与流型变化情况并测试其临界携液气量,结果表明,气藏水平井中水平井段的液体以液膜携带为主,但直井段中越接近井口,越以液滴携带为主,液滴模型也能适用于计算气藏水平井的连续携液临界流速。  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