全文获取类型
收费全文 | 40022篇 |
免费 | 2654篇 |
国内免费 | 1697篇 |
专业分类
管理学 | 5031篇 |
劳动科学 | 1篇 |
民族学 | 578篇 |
人才学 | 3篇 |
人口学 | 3195篇 |
丛书文集 | 2090篇 |
教育普及 | 2篇 |
理论方法论 | 2908篇 |
现状及发展 | 1篇 |
综合类 | 10318篇 |
社会学 | 14294篇 |
统计学 | 5952篇 |
出版年
2023年 | 187篇 |
2021年 | 385篇 |
2020年 | 821篇 |
2019年 | 1623篇 |
2018年 | 1763篇 |
2017年 | 1943篇 |
2016年 | 1999篇 |
2015年 | 1575篇 |
2014年 | 1685篇 |
2013年 | 5776篇 |
2012年 | 2053篇 |
2011年 | 1791篇 |
2010年 | 1425篇 |
2009年 | 1184篇 |
2008年 | 1158篇 |
2007年 | 974篇 |
2006年 | 925篇 |
2005年 | 963篇 |
2004年 | 1023篇 |
2003年 | 875篇 |
2002年 | 820篇 |
2001年 | 894篇 |
2000年 | 862篇 |
1999年 | 684篇 |
1998年 | 528篇 |
1997年 | 509篇 |
1996年 | 534篇 |
1995年 | 465篇 |
1994年 | 443篇 |
1993年 | 479篇 |
1992年 | 511篇 |
1991年 | 474篇 |
1990年 | 470篇 |
1989年 | 450篇 |
1988年 | 453篇 |
1987年 | 381篇 |
1986年 | 353篇 |
1985年 | 398篇 |
1984年 | 414篇 |
1983年 | 365篇 |
1982年 | 342篇 |
1981年 | 276篇 |
1980年 | 278篇 |
1979年 | 337篇 |
1978年 | 271篇 |
1977年 | 250篇 |
1976年 | 224篇 |
1975年 | 250篇 |
1974年 | 195篇 |
1973年 | 184篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
61.
教师的教育影响是附属于教师个体的特殊的教育影响。它具有高效性、灵活性、感染性、示范性等特征。教师应充分认识这些特征, 在教育实践中做到教书育人相结合、身教与言教相结合、理论与实践相结合。 相似文献
62.
对林业税费的经济学分析 总被引:3,自引:0,他引:3
田明华 《北京林业大学学报(社会科学版)》2002,(Z1)
该文运用经济学的基本工具———供给和需求曲线 ,以商品林为研究对象 ,探讨了林业税费的作用机理和内涵。该文认为商品林生产具有正的外部性 ,市场失灵使生产者将不能提供社会真正所需要的商品林数量。在封闭的市场条件下 ,林业税费会直接成为价格的一部分 ,商品林生产者应当能够获得正常利润 ,与税费高低无关 ,但会使一部分林地退出生产。林业补贴是一种负的林业税收。在开放市场经济条件下 ,国内商品林供应量低于没有林业税收时的商品林供应量 ,更低于考虑社会生态需求时的商品林供应量 ,造成巨大的社会福利损失 ,应减免林业税费、增加林业扶持、取消价格管制。该文进一步研究了与林业税费密切相关的森林采伐限额政策 ,认为对商品林应该完全取消采伐限额政策 相似文献
63.
Multiparameter evidence synthesis in epidemiology and medical decision-making: current approaches 总被引:1,自引:0,他引:1
A. E. Ades A. J. Sutton 《Journal of the Royal Statistical Society. Series A, (Statistics in Society)》2006,169(1):5-35
Summary. Alongside the development of meta-analysis as a tool for summarizing research literature, there is renewed interest in broader forms of quantitative synthesis that are aimed at combining evidence from different study designs or evidence on multiple parameters. These have been proposed under various headings: the confidence profile method, cross-design synthesis, hierarchical models and generalized evidence synthesis. Models that are used in health technology assessment are also referred to as representing a synthesis of evidence in a mathematical structure. Here we review alternative approaches to statistical evidence synthesis, and their implications for epidemiology and medical decision-making. The methods include hierarchical models, models informed by evidence on different functions of several parameters and models incorporating both of these features. The need to check for consistency of evidence when using these powerful methods is emphasized. We develop a rationale for evidence synthesis that is based on Bayesian decision modelling and expected value of information theory, which stresses not only the need for a lack of bias in estimates of treatment effects but also a lack of bias in assessments of uncertainty. The increasing reliance of governmental bodies like the UK National Institute for Clinical Excellence on complex evidence synthesis in decision modelling is discussed. 相似文献
64.
Polynomial spline regression models of low degree have proved useful in modeling responses from designed experiments in science and engineering when simple polynomial models are inadequate. Where there is uncertainty in the number and location of the knots, or breakpoints, of the spline, then designs that minimize the systematic errors resulting from model misspecification may be appropriate. This paper gives a method for constructing such all‐bias designs for a single variable spline when the distinct knots in the assumed and true models come from some specified set. A class of designs is defined in terms of the inter‐knot intervals and sufficient conditions are obtained for a design within this class to be all‐bias under linear, quadratic and cubic spline models. An example of the construction of all‐bias designs is given. 相似文献
65.
利益相关者理论及其对战略管理的启示 总被引:6,自引:0,他引:6
利益相关者理论将对企业的战略管理产生深远的影响。企业应重新定位组织与环境的关系,并将利益相关者关系看作是竞争优势的新来源,从而变革战略理念和战略行动。 相似文献
66.
This paper describes the design optimization of a robot sensor used for locating 3-D objects employing the Taguchi method in a computer simulation scenario. The location information from the sensor is to be utilized to control the movements of an industrial robot in a 'pick-and-place' or assembly operation. The Taguchi method, which is based on the Analysis-of-Variance (ANOVA) approach, is utilized to improve the performance of the sensor over a wider operating range. A review of the Taguchi method is presented along with step-by-step implementation details to identify and optimize the design parameters of the sensor. The method allows us to gauge the impact of various interactions present in the sensor system exclusively and permits us to single out those factors that have a dominant influence on the overall performance of the sensor. The investigation suggests that the Taguchi method is a more structured and efficient approach for achieving a robust design compared with the classical full factorial design approach. 相似文献
67.
高校加强大学生心理健康教育问题探索 总被引:2,自引:0,他引:2
本文针对近期大学生中出现的一系列心理问题,结合教学实际,就如何加强大学生心理健康教育进行了探讨,提出开设心理健康课、成立心理咨询中心等建议。 相似文献
68.
唯物史观具有三大基本特征, 即: 实践原则与主体性原则的内在一致, 它为唯物史观奠定了彻底的唯物主义理论基础; 历史发展过程的客体制约性与主体创造性的辩证统一, 它为唯物史观赋予了辩证的理论品格; 人的自由解放与历史进程的高度一致, 它使唯物史观获得了明确的价值指向。这三大基本特征有着内在的逻辑联系, 使唯物史观与其它一切历史观从根本上区别开来。 相似文献
69.
Jonathan H. Wright 《Econometric Reviews》2002,21(4):397-417
Many recent papers have used semiparametric methods, especially the log-periodogram regression, to detect and estimate long memory in the volatility of asset returns. In these papers, the volatility is proxied by measures such as squared, log-squared, and absolute returns. While the evidence for the existence of long memory is strong using any of these measures, the actual long memory parameter estimates can be sensitive to which measure is used. In Monte-Carlo simulations, I find that if the data is conditionally leptokurtic, the log-periodogram regression estimator using squared returns has a large downward bias, which is avoided by using other volatility measures. In United States stock return data, I find that squared returns give much lower estimates of the long memory parameter than the alternative volatility measures, which is consistent with the simulation results. I conclude that researchers should avoid using the squared returns in the semiparametric estimation of long memory volatility dependencies. 相似文献
70.
Computing maximum likelihood estimates from type II doubly censored exponential data 总被引:1,自引:0,他引:1
Arturo J. fernández José I. Bravo Íñigo De Fuentes 《Statistical Methods and Applications》2002,11(2):187-200
It is well-known that, under Type II double censoring, the maximum likelihood (ML) estimators of the location and scale parameters, θ and δ, of a twoparameter exponential distribution are linear functions
of the order statistics. In contrast, when θ is known, theML estimator of δ does not admit a closed form expression. It is shown, however, that theML estimator of the scale parameter exists and is unique. Moreover, it has good large-sample properties. In addition, sharp
lower and upper bounds for this estimator are provided, which can serve as starting points for iterative interpolation methods
such as regula falsi. Explicit expressions for the expected Fisher information and Cramér-Rao lower bound are also derived.
In the Bayesian context, assuming an inverted gamma prior on δ, the uniqueness, boundedness and asymptotics of the highest
posterior density estimator of δ can be deduced in a similar way. Finally, an illustrative example is included. 相似文献