全文获取类型
收费全文 | 101865篇 |
免费 | 3374篇 |
国内免费 | 96篇 |
专业分类
管理学 | 13102篇 |
劳动科学 | 24篇 |
民族学 | 885篇 |
人才学 | 37篇 |
人口学 | 7371篇 |
丛书文集 | 2901篇 |
教育普及 | 1篇 |
理论方法论 | 10103篇 |
现状及发展 | 1篇 |
综合类 | 7254篇 |
社会学 | 44026篇 |
统计学 | 19630篇 |
出版年
2023年 | 557篇 |
2022年 | 488篇 |
2021年 | 775篇 |
2020年 | 1664篇 |
2019年 | 2357篇 |
2018年 | 2286篇 |
2017年 | 3470篇 |
2016年 | 2622篇 |
2015年 | 2399篇 |
2014年 | 3075篇 |
2013年 | 19580篇 |
2012年 | 3030篇 |
2011年 | 2953篇 |
2010年 | 2754篇 |
2009年 | 2978篇 |
2008年 | 2840篇 |
2007年 | 2699篇 |
2006年 | 2861篇 |
2005年 | 2952篇 |
2004年 | 2540篇 |
2003年 | 2198篇 |
2002年 | 2347篇 |
2001年 | 2374篇 |
2000年 | 2030篇 |
1999年 | 1907篇 |
1998年 | 1625篇 |
1997年 | 1465篇 |
1996年 | 1428篇 |
1995年 | 1426篇 |
1994年 | 1359篇 |
1993年 | 1349篇 |
1992年 | 1340篇 |
1991年 | 1272篇 |
1990年 | 1231篇 |
1989年 | 1085篇 |
1988年 | 1147篇 |
1987年 | 1025篇 |
1986年 | 928篇 |
1985年 | 1114篇 |
1984年 | 1160篇 |
1983年 | 1037篇 |
1982年 | 953篇 |
1981年 | 869篇 |
1980年 | 833篇 |
1979年 | 891篇 |
1978年 | 781篇 |
1977年 | 699篇 |
1976年 | 663篇 |
1975年 | 637篇 |
1974年 | 531篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
M. Rae Moors 《Information, Communication & Society》2019,22(6):808-822
ABSTRACTThe Flint Water Crisis became a national news story in January of 2016, when major publishers such as The New York Times began covering the story. In the same month, an influx of social media activism occurred in response to the crisis, with citizens developing hashtag campaigns such as #FlintFwd in order to disseminate news and stories from a citizen’s perspective; these campaigns often positioned Flint positively ? as a recovering community ? rather than a city in the middle of a public health crisis, and often addressed not a national public but a local audience. This paper considers Flint-based social media activity to investigate the emergence of place-based activism within the ostensibly global network of social media. In doing so, it identifies three key themes; 1) leveraging social media to forward a critique of deficient journalistic storytelling; 2) using the affective process of storytelling via social media to claim authority over their own material offline existence, and 3) using place-based storytelling to implicate others as witnesses via the global network of social media. These themes coalesce around a distinctly critical logic of connectivity. This logic extends the notion of connectivity articulated by Van Dijck and Poell [2013. Understanding social media logic. Media and Communication, 1(1), 2–14.] and the strategies of platform activism explored by Tufekci [2017. Twitter and tear gas: The power and fragility of networked protest. New Haven: Yale University Press.] to explain how social media works to expose discrepancies between the public story of the water crisis and material, lived conditions of Flint, rendering visible a discursive identity of Flint thus far unrecognized. 相似文献
42.
Researchers have been developing various extensions and modified forms of the Weibull distribution to enhance its capability for modeling and fitting different data sets. In this note, we investigate the potential usefulness of the new modification to the standard Weibull distribution called odd Weibull distribution in income economic inequality studies. Some mathematical and statistical properties of this model are proposed. We obtain explicit expressions for the first incomplete moment, quantile function, Lorenz and Zenga curves and related inequality indices. In addition to the well-known stochastic order based on Lorenz curve, the stochastic order based on Zenga curve is considered. Since the new generalized Weibull distribution seems to be suitable to model wealth, financial, actuarial and especially income distributions, these findings are fundamental in the understanding of how parameter values are related to inequality. Also, the estimation of parameters by maximum likelihood and moment methods is discussed. Finally, this distribution has been fitted to United States and Austrian income data sets and has been found to fit remarkably well in compare with the other widely used income models. 相似文献
43.
以大豆生产者补贴政策改革作为切入点,将政策实施地区和非实施地区视为一次部分省份优化大豆、玉米种植结构的准自然实验,通过构建PSM-DID模型,考察大豆生产者补贴政策改革对农户种植结构调整的影响及其作用机制.结果表明:(1)大豆生产者补贴政策改革对农户种植结构调整具有显著的时间异质性,政策改革初年(2017年)大豆与玉米的面积之比显著提高6.5%,虽然2018年大豆与玉米的相对补贴额度出现大幅度增长,但大豆与玉米的面积之比仅显著提高3.4%;(2)预期相对收益的提升是2017年农户调整种植结构的重要原因,然而,经过对新制度一年的适应后,农户对种植玉米的路径依赖、补贴错位、地租的不合理增长以及大豆、玉米相对价格不理想等问题逐渐凸显,2018年农户重新调整种植决策,补贴的激励作用被迫减弱.基于此,研究结论为统筹大豆、玉米补贴机制可以促进农户种植结构调整提供经验性证据,也为在农业供给侧结构性改革和大豆振兴压力下如何持续改善种植结构提供政策启示. 相似文献
44.
Stephen J. Ruberg Frank E. Harrell Jr. Margaret Gamalo-Siebers Lisa LaVange J. Jack Lee Karen Price 《The American statistician》2019,73(1):319-327
ABSTRACTThe cost and time of pharmaceutical drug development continue to grow at rates that many say are unsustainable. These trends have enormous impact on what treatments get to patients, when they get them and how they are used. The statistical framework for supporting decisions in regulated clinical development of new medicines has followed a traditional path of frequentist methodology. Trials using hypothesis tests of “no treatment effect” are done routinely, and the p-value < 0.05 is often the determinant of what constitutes a “successful” trial. Many drugs fail in clinical development, adding to the cost of new medicines, and some evidence points blame at the deficiencies of the frequentist paradigm. An unknown number effective medicines may have been abandoned because trials were declared “unsuccessful” due to a p-value exceeding 0.05. Recently, the Bayesian paradigm has shown utility in the clinical drug development process for its probability-based inference. We argue for a Bayesian approach that employs data from other trials as a “prior” for Phase 3 trials so that synthesized evidence across trials can be utilized to compute probability statements that are valuable for understanding the magnitude of treatment effect. Such a Bayesian paradigm provides a promising framework for improving statistical inference and regulatory decision making. 相似文献
45.
Theory and Society - The massive expansion of US higher education after World War II is a sociological puzzle: a spectacular feat of state capacity-building in a highly federated polity. Prior... 相似文献
46.
47.
Proportional hazards are a common assumption when designing confirmatory clinical trials in oncology. This assumption not only affects the analysis part but also the sample size calculation. The presence of delayed effects causes a change in the hazard ratio while the trial is ongoing since at the beginning we do not observe any difference between treatment arms, and after some unknown time point, the differences between treatment arms will start to appear. Hence, the proportional hazards assumption no longer holds, and both sample size calculation and analysis methods to be used should be reconsidered. The weighted log‐rank test allows a weighting for early, middle, and late differences through the Fleming and Harrington class of weights and is proven to be more efficient when the proportional hazards assumption does not hold. The Fleming and Harrington class of weights, along with the estimated delay, can be incorporated into the sample size calculation in order to maintain the desired power once the treatment arm differences start to appear. In this article, we explore the impact of delayed effects in group sequential and adaptive group sequential designs and make an empirical evaluation in terms of power and type‐I error rate of the of the weighted log‐rank test in a simulated scenario with fixed values of the Fleming and Harrington class of weights. We also give some practical recommendations regarding which methodology should be used in the presence of delayed effects depending on certain characteristics of the trial. 相似文献
48.
49.
A. Knobel’ 《Russian social science review : a journal of translations》2019,60(2):137-161
This article analyzes the development prospects and problems for the Eurasian Economic Union (EAEU). It examines issues of integration within the EAEU, as well as interactions with other countries, both CIS (Commonwealth of Independent States) and non-CIS. The main problem of integration within the EAEU is the dominance of redistributive motives over productive ones. This article assesses the extent of Russian oil and gas transfers to EAEU partners and the impact of tax maneuvers on their size. It shows that the creation of mechanisms for redistributing profits within the EAEU will allow a positive economic effect to materialize from free trade agreements with non-CIS countries. The article assesses the risks for the EAEU related to Russia’s introduction of a unilateral ban on food imports from countries on the sanctions list and to the possible establishment of tariffs on trade with Ukraine. 相似文献
50.