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   933篇
  免费   63篇
  国内免费   10篇
管理学   105篇
民族学   6篇
人口学   26篇
丛书文集   40篇
理论方法论   77篇
综合类   202篇
社会学   73篇
统计学   477篇
  2023年   2篇
  2022年   9篇
  2021年   18篇
  2020年   14篇
  2019年   37篇
  2018年   52篇
  2017年   21篇
  2016年   32篇
  2015年   30篇
  2014年   36篇
  2013年   135篇
  2012年   57篇
  2011年   76篇
  2010年   49篇
  2009年   77篇
  2008年   57篇
  2007年   62篇
  2006年   37篇
  2005年   19篇
  2004年   11篇
  2003年   14篇
  2002年   17篇
  2001年   13篇
  2000年   8篇
  1999年   6篇
  1998年   3篇
  1997年   5篇
  1996年   6篇
  1995年   12篇
  1994年   10篇
  1993年   2篇
  1992年   1篇
  1985年   6篇
  1984年   18篇
  1983年   12篇
  1982年   14篇
  1981年   5篇
  1980年   9篇
  1979年   3篇
  1978年   11篇
排序方式: 共有1006条查询结果,搜索用时 296 毫秒
91.
张辛仪 《兰州学刊》2011,(12):210-212
怪诞既是君特·格拉斯小说的一大艺术特色,也令其晦涩难懂。文章以格拉斯的几部代表作为例,对格拉斯小说中怪诞的体现形式进行分析梳理,并对其作用和意义进行归纳总结,以探寻格拉斯的创作理念和美学思想。  相似文献   
92.
Time series models are presented, for which the seasonal-component estimates delivered by linear least squares signal extraction closely approximate those of the standard option of the widely-used Census X-11 program. Earlier work is extended by consideration of a broader class of models and by examination of asymmetric filters, in addition to the symmetric filter implicit in the adjustment of historical data. Various criteria that guide the specification of unobserved- components models are discussed, and a new preferred model is presented. Some nonstandard options in X-11 are considered in the Appendix.  相似文献   
93.
Confidence intervals for parameters that can be arbitrarily close to being unidentified are unbounded with positive probability [e.g. Dufour, J.-M., 1997. Some impossibility theorems in econometrics with applications to instrumental variables and dynamic models. Econometrica 65, 1365–1388; Pfanzagl, J. 1998. The nonexistence of confidence sets for discontinuous functionals. Journal of Statistical Planning and Inference 75, 9–20], and the asymptotic risks of their estimators are unbounded [Pötscher, B.M., 2002. Lower risk bounds and properties of confidence sets for ill-posed estimation problems with applications to spectral density and persistence estimation, unit roots, and estimation of long memory parameters. Econometrica 70, 1035–1065]. We extend these “impossibility results” and show that all tests of size α concerning parameters that can be arbitrarily close to being unidentified have power that can be as small as α for any sample size even if the null and the alternative hypotheses are not adjacent. The results are proved for a very general framework that contains commonly used models.  相似文献   
94.
For many diseases, logistic constraints render large incidence studies difficult to carry out. This becomes a drawback, particularly when a new study is needed each time the incidence rate is investigated in a new population. By carrying out a prevalent cohort study with follow‐up it is possible to estimate the incidence rate if it is constant. The authors derive the maximum likelihood estimator (MLE) of the overall incidence rate, λ, as well as age‐specific incidence rates, by exploiting the epidemiologic relationship, (prevalence odds) = (incidence rate) × (mean duration) (P/[1 ? P] = λ × µ). The authors establish the asymptotic distributions of the MLEs and provide approximate confidence intervals for the parameters. Moreover, the MLE of λ is asymptotically most efficient and is the natural estimator obtained by substituting the marginal maximum likelihood estimators for P and µ into P/[1 ? P] = λ × µ. Following‐up the subjects allows the authors to develop these widely applicable procedures. The authors apply their methods to data collected as part of the Canadian Study of Health and Ageing to estimate the incidence rate of dementia amongst elderly Canadians. The Canadian Journal of Statistics © 2009 Statistical Society of Canada  相似文献   
95.
Economic growth depends on human resources and human needs. The demographic age structure shapes both of these factors. We study five-year data from the OECD countries 1950–1990 in the framework of an age structure augmented neoclassical growth model with gradual technical adjustment. The model performs well in both pooled and panel estimations. The growth patterns of GDP per worker (labor productivity) in the OECD countries are to a large extent explained by age structure changes. The 50–64 age group has a positive influence, and the group above 65 contributes negatively, while younger age groups have ambiguous effects. However, the mechanism behind these age effects is not yet resolved. Received: 16 January 1997/Accepted: 2 July 1998  相似文献   
96.
The author considers estimation under a Gamma process model for degradation data. The setting for degradation data is one in which n independent units, each with a Gamma process with a common shape function and scale parameter, are observed at several possibly different times. Covariates can be incorporated into the model by taking the scale parameter as a function of the covariates. The author proposes using the maximum pseudo‐likelihood method to estimate the unknown parameters. The method requires usage of the Pool Adjacent Violators Algorithm. Asymptotic properties, including consistency, convergence rate and asymptotic distribution, are established. Simulation studies are conducted to validate the method and its application is illustrated by using bridge beams data and carbon‐film resistors data. The Canadian Journal of Statistics 37: 102‐118; 2009 © 2009 Statistical Society of Canada  相似文献   
97.
In this paper, we consider simple random sampling without replacement from a dichotomous finite population. We investigate accuracy of the Normal approximation to the Hypergeometric probabilities for a wide range of parameter values, including the nonstandard cases where the sampling fraction tends to one and where the proportion of the objects of interest in the population tends to the boundary values, zero and one. We establish a non-uniform Berry–Esseen theorem for the Hypergeometric distribution which shows that in the nonstandard cases, the rate of Normal approximation to the Hypergeometric distribution can be considerably slower than the rate of Normal approximation to the Binomial distribution. We also report results from a moderately large numerical study and provide some guidelines for using the Normal approximation to the Hypergeometric distribution in finite samples.  相似文献   
98.
The POT (peaks-over-threshold) approach consists in using the generalized Pareto distribution (GPD) to approximate the distribution of excesses over a threshold. In this paper, we consider this approximation using a generalized probability-weighted moments (GPWM) method. We study the asymptotic behaviour of our new estimators and also the functional bias of the GPD as an estimate of the distribution function of the excesses. A simulation study is provided in order to appreciate the efficiency of our approach.  相似文献   
99.
萨缪尔·亨廷顿9·11之后谈"文明的冲突"   总被引:1,自引:0,他引:1  
9·1 1之后 ,美国哈佛大学教授萨缪尔·亨廷顿声名大振 ,他的曾引起激烈争论的著作《文明的冲突 ,世界秩序的重建》在出版 5年之后 ,一下子跃升为美国最畅销书之一。美国国内外的许多人都在纷纷谈论 9·1 1是否是“文明的冲突”的象征或前奏 ,亨廷顿本人因此受到各种媒体的争相采访。  相似文献   
100.
蟾蜍离体心脏灌流实验表明:黄山采集的绞股兰、绞股兰茶剂、生晒参在低浓度时均能增加蟾蜍离体心脏的收缩振幅。其作用为:黄山绞股兰>生晒参>绞股兰茶剂,其后作用也以黄山绞股兰最强。高浓度时均能抑制心脏的搏动,使心脏停止于收缩状态,更换任氏液后心脏的搏动可以恢复。三种药物均对心率无明显的影响。  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