全文获取类型
收费全文 | 6338篇 |
免费 | 227篇 |
国内免费 | 45篇 |
专业分类
管理学 | 257篇 |
劳动科学 | 28篇 |
民族学 | 133篇 |
人才学 | 2篇 |
人口学 | 112篇 |
丛书文集 | 1623篇 |
理论方法论 | 332篇 |
综合类 | 3535篇 |
社会学 | 258篇 |
统计学 | 330篇 |
出版年
2024年 | 9篇 |
2023年 | 26篇 |
2022年 | 85篇 |
2021年 | 93篇 |
2020年 | 87篇 |
2019年 | 62篇 |
2018年 | 80篇 |
2017年 | 113篇 |
2016年 | 112篇 |
2015年 | 186篇 |
2014年 | 223篇 |
2013年 | 332篇 |
2012年 | 320篇 |
2011年 | 416篇 |
2010年 | 467篇 |
2009年 | 417篇 |
2008年 | 433篇 |
2007年 | 479篇 |
2006年 | 492篇 |
2005年 | 364篇 |
2004年 | 234篇 |
2003年 | 280篇 |
2002年 | 380篇 |
2001年 | 322篇 |
2000年 | 202篇 |
1999年 | 89篇 |
1998年 | 41篇 |
1997年 | 43篇 |
1996年 | 61篇 |
1995年 | 37篇 |
1994年 | 28篇 |
1993年 | 27篇 |
1992年 | 21篇 |
1991年 | 7篇 |
1990年 | 12篇 |
1989年 | 11篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 4篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1977年 | 1篇 |
排序方式: 共有6610条查询结果,搜索用时 0 毫秒
901.
华夏民族自称为龙的传人,彝族以龙、虎为图腾。在中国的英雄史诗中,史诗与"龙"和龙的精神有着密切的联系。本文以支格阿尔姓氏中龙"尔"[lu]的缘起;汉藏语系语言中龙"尔"[lu]的源流;龙"尔"[lu]是英雄人物的精神和力量;龙"尔"[lu]的精神是中华民族多元一体文化精神的集中体现为内容,以解读《支格阿尔》等英雄史诗蕴藏的文化内涵为主线,对英雄史诗中龙的精神进行分析研究,提出龙的精神就是英雄史诗中的英雄精神,龙的精神就是中华民族勇敢、无畏、团结、奋斗的民族精神。 相似文献
902.
To explore the application value of correspondence analysis in oncology, we adopted correspondence analysis method to analyze the relationship between the amount of food eaten in some cities in China and the male gastric carcinoma mortality. According to scatter plots of row and column points, there are regional differences among the male gastric carcinoma mortality in different cities of China. Southern male citizens ate more rice and salt, less wheaten food, and fewer light vegetables than northern ones. There may be some carcinogenic factors in some food. 相似文献
903.
ABSTRACTThis paper studies a cold standby repairable system with two identical components and one repairman having multiple vacations applying matrix-analytic methods. The lifetime of the component follows a phase-type distribution. The repair times and the vacation times of the repairman are governed by different phase-type distributions, respectively. For this system, the Markov process governing the system is constructed. The system is studied in a transient and stationary regime, the availability, the reliability, the rates of occurrence of the different types of failures, and the working probability of the repairman are calculated, respectively. A numerical application is performed to illustrate the calculations. 相似文献
904.
905.
906.
The authors derive the analytic expressions for the mean and variance of the log-likelihood ratio for testing equality of k (k ≥ 2) normal populations, and suggest a chi-square approximation and a gamma approximation to the exact null distribution. Numerical comparisons show that the two approximations and the original beta approximation of Neyman and Pearson (1931) are all accurate, and the gamma approximation is the most accurate. 相似文献
907.
Zero-inflated Poisson mixed regression models are popular approaches to analyze clustered count data with excess zeros. Prior to application of these models, it is essential to examine the necessity of the adjustment for zero outcomes. The existing literature, however, has focused only on score tests for testing the suitability of zero-inflated models for correlated count data. In view of the observed bias and non-optimal size of score tests, it deserves further investigation of other alternative ways for the test. This article aims to explore the use of the null Wald and likelihood ratio tests for zero-inflation in correlated count data. Our simulation study shows that both the null Wald and likelihood ratio tests outperform the score test of Xiang et al. (2006) in terms of statistical power, regardless of the computational convenience of the score test. A bootstrap null Wald statistic is also proposed, which results in improved performance in terms of the size and power of the test. 相似文献
908.
Whereas large-sample properties of the estimators of survival distributions using censored data have been studied by many authors, exact results for small samples have been difficult to obtain. In this paper we obtain the exact expression for the ath moment (a > 0) of the Bayes estimator of survival distribution using the censored data under proportional hazard model. Using the exact expression we compute the exact mean, variance and MSE of the Bayes estimator. Also two estimators ofthe mean survival time based on the Kaplan-Meier estimator and the Bayes estimator are compared for small samples under proportional hazards. 相似文献
909.
The present article intends to develop some imputation methods to reduce the impact of non response at both the occasions in two-occasion successive (rotation) sampling. Utilizing the auxiliary information, which is only available at the current occasion, estimators have been proposed for estimating the population mean at the current occasion. Estimators for the current occasion are also derived as a particular case when there is non response either on the first occasion or second occasion. Behaviors of the proposed estimators are studied and their respective optimum replacement policies are also discussed. To study the effectiveness of the suggested imputation methods, performances of the proposed estimators are compared in two different situations, with and without non response. The results obtained are demonstrated with the help of empirical studies. 相似文献
910.
In many medical comparative studies (e.g., comparison of two treatments in an otolaryngological study), subjects may produce either bilateral (e.g., responses from a pair of ears) or unilateral (response from only one ear) data. For bilateral cases, it is meaningful to assume that the information between the two ears from the same subject are generally highly correlated. In this article, we would like to test the equality of the successful cure rates between two treatments with the presence of combined unilateral and bilateral data. Based on the dependence and independence models, we study ten test statistics which utilize both the unilateral and bilateral data. The performance of these statistics will be evaluated with respect to their empirical Type I error rates and powers under different configurations. We find that both Rosner's and Wald-type statistics based on the dependence model and constrained maximum likelihood estimates (under the null hypothesis) perform satisfactorily for small to large samples and are hence recommended. We illustrate our methodologies with a real data set from an otolaryngology study. 相似文献