全文获取类型
收费全文 | 12982篇 |
免费 | 287篇 |
专业分类
管理学 | 1663篇 |
民族学 | 51篇 |
人才学 | 1篇 |
人口学 | 1135篇 |
丛书文集 | 79篇 |
教育普及 | 2篇 |
理论方法论 | 1209篇 |
综合类 | 338篇 |
社会学 | 6529篇 |
统计学 | 2262篇 |
出版年
2021年 | 68篇 |
2020年 | 192篇 |
2019年 | 227篇 |
2018年 | 259篇 |
2017年 | 386篇 |
2016年 | 294篇 |
2015年 | 235篇 |
2014年 | 262篇 |
2013年 | 2108篇 |
2012年 | 401篇 |
2011年 | 326篇 |
2010年 | 220篇 |
2009年 | 238篇 |
2008年 | 273篇 |
2007年 | 289篇 |
2006年 | 221篇 |
2005年 | 361篇 |
2004年 | 306篇 |
2003年 | 268篇 |
2002年 | 273篇 |
2001年 | 324篇 |
2000年 | 306篇 |
1999年 | 314篇 |
1998年 | 216篇 |
1997年 | 213篇 |
1996年 | 219篇 |
1995年 | 189篇 |
1994年 | 207篇 |
1993年 | 180篇 |
1992年 | 241篇 |
1991年 | 235篇 |
1990年 | 211篇 |
1989年 | 223篇 |
1988年 | 196篇 |
1987年 | 187篇 |
1986年 | 189篇 |
1985年 | 176篇 |
1984年 | 208篇 |
1983年 | 205篇 |
1982年 | 168篇 |
1981年 | 138篇 |
1980年 | 139篇 |
1979年 | 167篇 |
1978年 | 138篇 |
1977年 | 119篇 |
1976年 | 102篇 |
1975年 | 101篇 |
1974年 | 97篇 |
1973年 | 94篇 |
1972年 | 66篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
盆景艺术风格是盆景艺术家的创作个性在作品中的外在表现 ,它对盆景艺术的发展起着很重要的作用 ,人们对盆景的感性认识直接来源于盆景的风格。大部分盆景方面的书和文章都会涉及到盆景艺术风格的问题 ,但是 ,迄今为止对盆景艺术风格的形成和发展进行过系统研究的人还不是很多。基于对艺术发展规律和中国各种艺术风格盆景发展历史的研究 ,该文详细论述了影响盆景艺术风格形成和发展的内在、外在因素及它们之间的关系 ,并对怎样给我国盆景艺术注入新的活力提出了一些建议 ,对我国盆景艺术的发展和创新起到一定的指导作用 相似文献
102.
Terrorist actions are aimed at maximizing harm (health, psychological, economical, and political) through the combined physical impacts of the act and fear. Immediate and effective response to a terrorist act is critical to limit human and environmental harm, effectively restore facility function, and maintain public confidence. Though there have been terrorist attacks in public facilities that we have learned from, overall our experiences in restoration of public facilities following a terrorist attack are limited. Restoration of public facilities following a release of a hazardous material is inherently far more complex than in industrial settings and has many unique technical, economic, social, and political challenges. For example, there may be a great need to quickly restore the facility to full operation and allow public access even though it was not designed for easy or rapid restoration, and critical information is needed for quantitative risk assessment and effective restoration must be anticipated to be incomplete and uncertain. Whereas present planning documents have substantial linearity in their organization, the “adaptive management” paradigm provides a constructive parallel paradigm for restoration of public facilities that anticipates and plans for uncertainty, inefficiencies, and stakeholder participation. Adaptive management grew out of the need to manage and restore natural resources in highly complex and changing environments with limited knowledge about causal relationships and responses to restoration actions. Similarities between natural resource management and restoration of a public facility after a terrorist attack suggest that integration of adaptive management principles explicitly into restoration processes will result in substantially enhanced and flexible responses necessary to meet the uncertainties of potential terrorist attacks. 相似文献
103.
The authors consider Bayesian analysis for continuous‐time Markov chain models based on a conditional reference prior. For such models, inference of the elapsed time between chain observations depends heavily on the rate of decay of the prior as the elapsed time increases. Moreover, improper priors on the elapsed time may lead to improper posterior distributions. In addition, an infinitesimal rate matrix also characterizes this class of models. Experts often have good prior knowledge about the parameters of this matrix. The authors show that the use of a proper prior for the rate matrix parameters together with the conditional reference prior for the elapsed time yields a proper posterior distribution. The authors also demonstrate that, when compared to analyses based on priors previously proposed in the literature, a Bayesian analysis on the elapsed time based on the conditional reference prior possesses better frequentist properties. The type of prior thus represents a better default prior choice for estimation software. 相似文献
104.
经济系统的演化与政策作用 总被引:1,自引:0,他引:1
该文根据耗散结构的基本原理 ,将经济系统划分为平衡态、过渡态和自组织状态。并将政策因素看成是一种外部调控手段 ,分析了在经济系统的不同状态下 ,政策因素对改变系统的结构及变化趋势所起的不同作用 相似文献
105.
106.
该文分析了法国会计模式的特点和影响因素 ,认为法国会计模式与中国会计模式存在相似之处 ,并借鉴法国 1 996年以来会计改革的经验 ,对完善我国会计模式提出了建议 相似文献
107.
Stevan Harnad Tim Brody Franois Vallires Les Carr Steve Hitchcock Yves Gingras Charles Oppenheim Heinrich Stamerjohanns Eberhard R. Hilf 《Serials Review》2004,30(4):310-314
The research access/impact problem arises because journal articles are not accessible to all of their would-be users; hence, they are losing potential research impact. The solution is to make all articles Open Access (OA; i.e., accessible online, free for all). OA articles have significantly higher citation impact than non-OA articles. There are two roads to OA: the “golden” road (publish your article in an OA journal) and the “green” road (publish your article in a non-OA journal but also self-archive it in an OA archive). Only 5% of journals are gold, but over 90% are already green (i.e., they have given their authors the green light to self-archive); yet only about 10–20% of articles have been self-archived. To reach 100% OA, self-archiving needs to be mandated by researchers' employers and funders, as the United Kingdom and the United States have recently recommended, and universities need to implement that mandate. 相似文献
108.
The ability to infer parameters of gene regulatory networks is emerging as a key problem in systems biology. The biochemical
data are intrinsically stochastic and tend to be observed by means of discrete-time sampling systems, which are often limited
in their completeness. In this paper we explore how to make Bayesian inference for the kinetic rate constants of regulatory
networks, using the stochastic kinetic Lotka-Volterra system as a model. This simple model describes behaviour typical of
many biochemical networks which exhibit auto-regulatory behaviour. Various MCMC algorithms are described and their performance
evaluated in several data-poor scenarios. An algorithm based on an approximating process is shown to be particularly efficient. 相似文献
109.
In this paper, we deal with a discrete-time multiserver retrial queue with finite population. Firstly, we study the Markov chain at the epochs immediately after slot boundaries making emphasis on the computation of its steady-state distribution. Then, the main performance measures are investigated. Besides, we simulate the waiting time of a customer in the retrial group under three different queueing policies. Some numerical examples are given to illustrate the analysis. 相似文献
110.
D. R. Cox 《Journal of the Royal Statistical Society. Series A, (Statistics in Society)》2003,166(2):241-246
Summary. Possible health hazards from mobile phones arise from the use of the phones themselves and via the base stations that relay signals. Except for an increase in traffic accidents induced by the use of mobile phones in cars the evidence for a health hazard is at most indirect, but it cannot be entirely dismissed; the phones have not been widely used for sufficiently long for direct epidemiological studies to have high sensitivity for detecting any induced incidence of cancer, for example. The background and evidence are briefly reviewed and the steps taken in the UK to make information widely available described. 相似文献