全文获取类型
收费全文 | 37222篇 |
免费 | 740篇 |
国内免费 | 2篇 |
专业分类
管理学 | 5010篇 |
民族学 | 186篇 |
人才学 | 1篇 |
人口学 | 3491篇 |
丛书文集 | 147篇 |
教育普及 | 3篇 |
理论方法论 | 3316篇 |
现状及发展 | 1篇 |
综合类 | 431篇 |
社会学 | 18375篇 |
统计学 | 7003篇 |
出版年
2023年 | 217篇 |
2021年 | 261篇 |
2020年 | 640篇 |
2019年 | 878篇 |
2018年 | 1111篇 |
2017年 | 1414篇 |
2016年 | 1091篇 |
2015年 | 764篇 |
2014年 | 1023篇 |
2013年 | 6261篇 |
2012年 | 1341篇 |
2011年 | 1231篇 |
2010年 | 912篇 |
2009年 | 759篇 |
2008年 | 937篇 |
2007年 | 896篇 |
2006年 | 916篇 |
2005年 | 791篇 |
2004年 | 783篇 |
2003年 | 685篇 |
2002年 | 750篇 |
2001年 | 892篇 |
2000年 | 848篇 |
1999年 | 777篇 |
1998年 | 605篇 |
1997年 | 537篇 |
1996年 | 550篇 |
1995年 | 538篇 |
1994年 | 487篇 |
1993年 | 504篇 |
1992年 | 587篇 |
1991年 | 568篇 |
1990年 | 530篇 |
1989年 | 500篇 |
1988年 | 489篇 |
1987年 | 423篇 |
1986年 | 431篇 |
1985年 | 479篇 |
1984年 | 447篇 |
1983年 | 408篇 |
1982年 | 349篇 |
1981年 | 291篇 |
1980年 | 299篇 |
1979年 | 339篇 |
1978年 | 284篇 |
1977年 | 260篇 |
1976年 | 208篇 |
1975年 | 225篇 |
1974年 | 195篇 |
1973年 | 168篇 |
排序方式: 共有10000条查询结果,搜索用时 11 毫秒
941.
AbstractWe propose a cure rate survival model by assuming that the number of competing causes of the event of interest follows the negative binomial distribution and the time to the event of interest has the Birnbaum-Saunders distribution. Further, the new model includes as special cases some well-known cure rate models published recently. We consider a frequentist analysis for parameter estimation of the negative binomial Birnbaum-Saunders model with cure rate. Then, we derive the appropriate matrices for assessing local influence on the parameter estimates under different perturbation schemes. We illustrate the usefulness of the proposed model in the analysis of a real data set from the medical area. 相似文献
942.
ABSTRACTLet T1: n ? T2: n ? ??? ? Tn: n be ordered lifetimes of components of a parallel system. In this article, the α-quantile past lifetime from the failure of the component with lifetime Tr: n provided that the system has failed at or before time t has been introduced. Then, some properties of this measure have been studied. 相似文献
943.
ABSTRACTWe introduce a new parsimonious bimodal distribution, referred to as the bimodal skew-symmetric Normal (BSSN) distribution, which is potentially effective in capturing bimodality, excess kurtosis, and skewness. Explicit expressions for the moment-generating function, mean, variance, skewness, and excess kurtosis were derived. The shape properties of the proposed distribution were investigated in regard to skewness, kurtosis, and bimodality. Maximum likelihood estimation was considered and an expression for the observed information matrix was provided. Illustrative examples using medical and financial data as well as simulated data from a mixture of normal distributions were worked. 相似文献
944.
AbstractThis article is devoted to study the problem of test of periodicity in the restricted exponential autoregressive (EXPAR) model. The local asymptotic normality property, of this model, is shown via the adapted sufficient conditions due to Swensen (1985). Using this result, in the case where the innovation density is specified, we obtain a parametric local asymptotic “most stringent” test. 相似文献
945.
ABSTRACTA new discrete distribution that depends on two parameters is introduced in this article. From this new distribution the geometric distribution is obtained as a special case. After analyzing some of its properties such as moments and unimodality, recurrences for the probability mass function and differential equations for its probability generating function are derived. In addition to this, parameters are estimated by maximum likelihood estimation numerically maximizing the log-likelihood function. Expected frequencies are calculated for different sets of data to prove the versatility of this discrete model. 相似文献
946.
Jorge M. Arevalillo 《统计学通讯:理论与方法》2013,42(11):3196-3205
ABSTRACTThis article is concerned with the derivation and study of the Cornish-Fisher expansion for a wide class of estimators of the parameter in the first order autoregressive process. Second and third order Cornish-Fisher approximations to the quantile of the distribution of the corresponding asymptotically normal standardized statistic are stated explicitly and their accuracy is examined, both theoretically and numerically, by comparing them with the exact value of the quantile obtained by Monte Carlo simulation. 相似文献
947.
Victor M. Guerrero 《统计学通讯:理论与方法》2013,42(21):4568-4585
We consider the problem of estimating a trend with different amounts of smoothness for segments of a time series subjected to different variability regimes. We propose using an unobserved components model to consider the existence of at least two data segments. We first fix some desired percentages of smoothness for the trend segments and deduce the corresponding smoothing parameters involved. Once the size of each segment is chosen, the smoothing formulas here derived produce trend estimates for all segments with the desired smoothness as well as their corresponding estimated variances. Empirical examples from demography and economics illustrate our proposal. 相似文献
948.
ABSTRACTThis paper presents systematic methods of construction of optimal block designs for a double cross experiments for both even and odd values of “p” parental lines. The both even and odd values of designs are derived by using initial block of unreduced balanced incomplete block designs and initial block of row–column designs given by Bose et al. (1953) and Gupta and Choi (1998), respectively. In this attempt we have found some new universally optimal block designs for double cross experiments. 相似文献
949.
AbstractIn this article, we have considered the problem of estimation of population variance on current (second) occasion in two occasion successive (rotation) sampling. A class of estimators of population variance has been proposed and its asymptotic properties have been discussed. The proposed class of estimators is compared with the sample variance estimator when there is no matching from the previous occasion and the Singh et al. (2013) estimator. Optimum replacement policy is discussed. It has been shown that the suggested estimator is more efficient than the Singh et al. (2013) estimator and a usual unbiased estimator when there is no matching. An empirical study is carried out in support of the present study. 相似文献
950.
ABSTRACTRandom vectors with positive components are common in many applied fields, for example, in meteorology, when daily precipitation is measured through a region Marchenko and Genton (2010). Frequently, the log-normal multivariate distribution is used for modeling this type of data. This modeling approach is not appropriate for data with high asymmetry or kurtosis. Consequently, more flexible multivariate distributions than the log-normal multivariate are required. As an alternative to this distribution, we propose the log-alpha-power multivariate and log-skew-normal multivariate models. The first model is an extension for positive data of the fractional order statistics model Durrans (1992). The second one is an extension of the log-skew-normal model studied by Mateu-Figueras and Pawlowsky-Glahn (2007). We study parameter estimation for these models by means of pseudo-likelihood and maximum likelihood methods. We illustrate the proposal analyzing a real dataset. 相似文献