全文获取类型
收费全文 | 15689篇 |
免费 | 243篇 |
国内免费 | 55篇 |
专业分类
管理学 | 1720篇 |
劳动科学 | 7篇 |
民族学 | 219篇 |
人才学 | 4篇 |
人口学 | 2547篇 |
丛书文集 | 844篇 |
理论方法论 | 803篇 |
综合类 | 3524篇 |
社会学 | 4873篇 |
统计学 | 1446篇 |
出版年
2024年 | 3篇 |
2023年 | 27篇 |
2022年 | 77篇 |
2021年 | 110篇 |
2020年 | 80篇 |
2019年 | 87篇 |
2018年 | 1751篇 |
2017年 | 1789篇 |
2016年 | 1197篇 |
2015年 | 177篇 |
2014年 | 248篇 |
2013年 | 364篇 |
2012年 | 576篇 |
2011年 | 1452篇 |
2010年 | 1370篇 |
2009年 | 1136篇 |
2008年 | 1132篇 |
2007年 | 1311篇 |
2006年 | 343篇 |
2005年 | 524篇 |
2004年 | 479篇 |
2003年 | 495篇 |
2002年 | 433篇 |
2001年 | 327篇 |
2000年 | 220篇 |
1999年 | 50篇 |
1998年 | 26篇 |
1997年 | 26篇 |
1996年 | 55篇 |
1995年 | 26篇 |
1994年 | 20篇 |
1993年 | 9篇 |
1992年 | 12篇 |
1991年 | 12篇 |
1990年 | 6篇 |
1989年 | 5篇 |
1988年 | 12篇 |
1987年 | 4篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1977年 | 3篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 281 毫秒
51.
本文首先综述了国内外学者在研究塑性材料耐冲蚀磨损性能方面所取得的主要成果,并在专门建立的灰磨试验台上,对电站燃煤锅炉对流受热面常用材料20号钢、12Cr_1MoV合金铜以及铜、铝四种塑性材料进行了耐飞灰冲蚀磨损性能的试验研究。提出用材料的体积磨损率来定义材料的耐冲蚀磨损性能系数。并用它表征塑性材料的抗磨性能。该系数可直接应用于计算燃煤锅炉对流受热面的安全烟速。 相似文献
52.
网络教育的成本与效益分析 总被引:6,自引:0,他引:6
在分析网络教育的特点及发展趋势的基础上 ,对网络教育的成本与效益及相关性问题进行了探讨 ,并提出了网络教育成本分担 ,阐述了通过提高网络教育的利用效率与效益 ,降低网络教育直接成本 ,促进网络教育持续不断发展 相似文献
53.
We employ vector autoregressive techniques to determine the current state of the labor queue. Unemployment rate differentials
have narrowed in recent years, potentially due to a change in the queue ordering, though a tight labor market and a stable
queue would yield similar results. We find no evidence that the queue ordering has changed, which brings into question the
resiliency of gains made by minority groups. We employ the same techniques to reveal the state of the queue across geographic
regions and find that substantial differences exist across regions, implying variation in the relative labor force status
of demographic groups. 相似文献
54.
Point processes are the stochastic models most suitable for describing physical phenomena that appear at irregularly spaced
times, such as the earthquakes. These processes are uniquely characterized by their conditional intensity, that is, by the
probability that an event will occur in the infinitesimal interval (t, t+Δt), given the history of the process up tot. The seismic phenomenon displays different behaviours on different time and size scales; in particular, the occurrence of
destructive shocks over some centuries in a seismogenic region may be explained by the elastic rebound theory. This theory
has inspired the so-called stress release models: their conditional intensity translates the idea that an earthquake produces
a sudden decrease in the amount of strain accumulated gradually over time along a fault, and the subsequent event occurs when
the stress exceeds the strength of the medium. This study has a double objective: the formulation of these models in the Bayesian
framework, and the assignment to each event of a mark, that is its magnitude, modelled through a distribution that depends
at timet on the stress level accumulated up to that instant. The resulting parameter space is constrained and dependent on the data,
complicating Bayesian computation and analysis. We have resorted to Monte Carlo methods to solve these problems. 相似文献
55.
Michael S. Rendall Ryan Admiraal Alessandra DeRose Paola DiGiulio Mark S. Handcock Filomena Racioppi 《Statistical Methods and Applications》2008,17(4):519-539
In non-experimental research, data on the same population process may be collected simultaneously by more than one instrument.
For example, in the present application, two sample surveys and a population birth registration system all collect observations
on first births by age and year, while the two surveys additionally collect information on women’s education. To make maximum
use of the three data sources, the survey data are pooled and the population data introduced as constraints in a logistic
regression equation. Reductions in standard errors about the age and birth-cohort parameters of the regression equation in
the order of three-quarters are obtained by introducing the population data as constraints. A halving of the standard errors
about the education parameters is achieved by pooling observations from the larger survey dataset with those from the smaller
survey. The percentage reduction in the standard errors through imposing population constraints is independent of the total
survey sample size. 相似文献
56.
57.
58.
随着科学技术的突飞猛进以及经济全球化的推进 ,信息传播日益加快 ,跨文化交际广泛 ,翻译也随之发展成为一种服务于多种目的、多层次的综合性活动。翻译除了重视传统的语言分析和文本对照外 ,还开始强调对语言翻译过程中所涉及的文化现象进行研究。在此情况下 ,译者须“身兼数职”才能满足翻译工作的需求。本文以较丰富的例子、详尽地阐述了新时期翻译工作者所必须具备的素质。只有具备这些素质才能保证译者译得准确、译得顺畅、译得自然 相似文献
59.
Gayane Novikova 《Transition Studies Review》2004,11(3):213-223
The collapse of the USSR was accompanied by transformation of the South Caucasian latent ethnopolitical conflicts into local wars. Today the situation in the area of the conflicts is “neither war, nor peace”. Three unresolved conflicts of the South Caucasus can be considered as one of the most serious obstacles for establishing a regional security system.The article gives the general characteristics of these conflicts, the trends of their development, taking into account the time factor, and analyzes the behavioral models of the main players – de jure recognized and unrecognized de facto states of the South Caucasus. The basic objective of the main players should be to keep the situation on a level preventing the resumption of the armed conflicts. The attempts of forced resolution of the conflicts are fraught with destabilization of the situation not only in the area of any of these conflicts but in the whole region. 相似文献
60.
《项狄传》中有一个关于意义的哲学主题。斯特恩认为 ,语言和理性不能表达意义 ,只有构成感性内容的东西 ,如情感、想象 ,动作等 ,才是意义的源泉。 相似文献