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   3261篇
  免费   81篇
  国内免费   14篇
管理学   196篇
民族学   8篇
人口学   82篇
丛书文集   120篇
理论方法论   82篇
综合类   866篇
社会学   129篇
统计学   1873篇
  2024年   1篇
  2023年   10篇
  2022年   11篇
  2021年   24篇
  2020年   51篇
  2019年   84篇
  2018年   98篇
  2017年   153篇
  2016年   67篇
  2015年   74篇
  2014年   137篇
  2013年   813篇
  2012年   265篇
  2011年   134篇
  2010年   136篇
  2009年   100篇
  2008年   140篇
  2007年   124篇
  2006年   148篇
  2005年   120篇
  2004年   96篇
  2003年   85篇
  2002年   70篇
  2001年   73篇
  2000年   65篇
  1999年   42篇
  1998年   27篇
  1997年   34篇
  1996年   32篇
  1995年   23篇
  1994年   10篇
  1993年   16篇
  1992年   15篇
  1991年   10篇
  1990年   8篇
  1989年   9篇
  1988年   10篇
  1987年   3篇
  1986年   3篇
  1985年   8篇
  1984年   4篇
  1983年   5篇
  1982年   4篇
  1981年   4篇
  1980年   4篇
  1979年   3篇
  1978年   3篇
排序方式: 共有3356条查询结果,搜索用时 62 毫秒
121.
We propose an improved difference-cum-exponential ratio type estimator for estimating the finite population mean in simple and stratified random sampling using two auxiliary variables. We obtain properties of the estimators up to first order of approximation. The proposed class of estimators is found to be more efficient than the usual sample mean estimator, ratio estimator, exponential ratio type estimator, usual two difference type estimators, Rao (1991) estimator, Gupta and Shabbir (2008) estimator, and Grover and Kaur (2011) estimator. We use six real data sets in simple random sampling and two in stratified sampling for numerical comparisons.  相似文献   
122.
The occurrence of nonresponse is very much plebeian in surveys, which troubles the analysis, and hence, an inappropriate inference is left out. To counterbalance the sour effects of the incompleteness, fresh imputation techniques have been proposed with the aid of multi-auxiliary variates for the estimation of population mean on successive waves. Properties of the proposed estimators have been elaborated, and they have been compared with the work of Priyanka et al. (2015). Detailed simulation study is carried out to substantiate the empirical and theoretical results. Several possible cases have been addressed in which nonresponse can occur.  相似文献   
123.
In this paper, the classical statistical test based on intuitionistic fuzzy hypotheses in relation to the underlying population parametric is extended. In this approach, the type-I, type-II, power of test, and p-value are extended for intuitionistic fuzzy hypotheses. Throughout the paper, some applied examples are provided for both parametric and non parametric cases to clarify the discussions.  相似文献   
124.
For the slope parameter of the measurement error model with the reliability ratio known, this article constructs a fiducial generalized confidence interval (FGCI) which is proved to have correct asymptotic coverage. Simulation results demonstrate that the FGCI often outperforms the existing intervals in terms of empirical coverage probability, average interval length, and false parameter coverage rate. Two examples are also provided to illustrate our approach.  相似文献   
125.
In this article, we consider statistical inference for longitudinal partial linear models when the response variable is sometimes missing with missingness probability depending on the covariate that is measured with error. A generalized empirical likelihood (GEL) method is proposed by combining correction attenuation and quadratic inference functions. The method that takes into consideration the correlation within groups is used to estimate the regression coefficients. Furthermore, residual-adjusted empirical likelihood (EL) is employed for estimating the baseline function so that undersmoothing is avoided. The empirical log-likelihood ratios are proven to be asymptotically Chi-squared, and the corresponding confidence regions for the parameters of interest are then constructed. Compared with methods based on NAs, the GEL does not require consistent estimators for the asymptotic variance and bias. The numerical study is conducted to compare the performance of the EL and the normal approximation-based method, and a real example is analysed.  相似文献   
126.
In clinical studies, pairwise comparisons are frequently performed to examine differences in efficacy between treatments. The statistical methods of pairwise comparisons are available when treatment responses are measured on an ordinal scale. The Wilcoxon–Mann–Whitney test and the latent normal model are popular examples. However, these procedures cannot be used to compare treatments in parallel groups (a two-way design) when overall type I error must be controlled. In this paper, we explore statistical approaches to the pairwise testing of treatments that satisfy the requirements of a two-way layout. The results of our simulation indicate that the latent normal approach is superior to the Wilcoxon–Mann–Whitney test. Clinical examples are used to illustrate our suggested testing methods.  相似文献   
127.
128.
固定资产投资与国内生产总值的误差修正模型研究   总被引:1,自引:0,他引:1  
运用协整理论和误差修正模型研究固定资产投资和国内生产总值之间的关系,可以发现它们之间存在长期均衡的协整关系,使用误差修正模型比普通的单变量方程更能反映两者长期和短期的关系,还可以避免谬误回归问题。  相似文献   
129.
基于“3R&I”原则的循环经济模式研究   总被引:2,自引:0,他引:2  
我国当前经济高速增长的要求与有限资源和环境支持能力之间存在严重矛盾。实施循环经济是贯彻落实我国节能减排政策的有效途径,如何发展循环经济是我们面临的重大课题。目前循环经济的实施主要是依据“3R”原则,而这些原则有明显的不足之处。针对“3R”原则的局限性,提出基于创新的循环经济“3R&I”原则。创新是实现“减量化”、“再利用”、“资源化”的前提,也是实现经济持续循环的保证。循环经济本质上是一种创新经济。  相似文献   
130.
对牛顿环测量凸透镜曲率半径实验中的误差进行了理论分析和半定量分析,指出了误差的主要来源及相应的处理方法.对于测量曲率半径P>lm的平凸透镜,公式R=Dm2-Dn2/4(m-n)λ的理论相对误差小于10-8;逐差法可以消除形变带来的系统误差;由于形变的影响应从第5级以后开始计数,对于R>1m的凸透镜要得到小于10-3的相对误差,级数应小于50,级数差值应大于30.钠光灯作为光源的系统相对误差为7.1×10-4.  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