首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   14982篇
  免费   617篇
  国内免费   181篇
管理学   1551篇
劳动科学   2篇
民族学   119篇
人才学   1篇
人口学   386篇
丛书文集   947篇
理论方法论   521篇
综合类   8437篇
社会学   1215篇
统计学   2601篇
  2024年   20篇
  2023年   131篇
  2022年   128篇
  2021年   169篇
  2020年   294篇
  2019年   342篇
  2018年   381篇
  2017年   470篇
  2016年   423篇
  2015年   492篇
  2014年   801篇
  2013年   1593篇
  2012年   1052篇
  2011年   1034篇
  2010年   829篇
  2009年   790篇
  2008年   905篇
  2007年   991篇
  2006年   914篇
  2005年   795篇
  2004年   699篇
  2003年   580篇
  2002年   485篇
  2001年   356篇
  2000年   264篇
  1999年   152篇
  1998年   82篇
  1997年   91篇
  1996年   84篇
  1995年   64篇
  1994年   60篇
  1993年   54篇
  1992年   42篇
  1991年   22篇
  1990年   29篇
  1989年   33篇
  1988年   27篇
  1987年   23篇
  1986年   21篇
  1985年   15篇
  1984年   15篇
  1983年   7篇
  1982年   6篇
  1981年   9篇
  1980年   2篇
  1979年   1篇
  1978年   1篇
  1977年   1篇
  1975年   1篇
排序方式: 共有10000条查询结果,搜索用时 281 毫秒
221.
为了更科学地进行政策分析和研究,评测已有装配式建筑政策体系完善与否,从政策工具的视角,将基本政策工具、装配式建筑驱动主体和产业价值链组合成一个三维研究框架.利用该框架,运用内容分析法对中国现有13份中央政府级装配式建筑政策文本中采用的政策工具进行计量和分析.得出环境型和供给型政策工具过溢,针对企业和科研机构的政策工具缺失,装配式建筑产业价值链维度的政策工具滞后于其价值实现环节等结论,并为完善装配式建筑政策体系提出建议.  相似文献   
222.
随着国家社科基金项目对“三农”问题研究的资助力度不断加强,相关研究发展迅速且成果卓著,对此进行整体梳理,既有助于总结以往研究的经验,也有益于相关问题研究的不断深入.文章以1991-2015年立项的3 375项“三农”问题国家社科基金项目及其18 770篇成果论文为研究对象,对项目信息、成果论文、研究热点与评价等方面进行计量分析,全面呈现中国“三农”问题近30年的发展与研究状况.研究表明,农民、新生代农民工、新农村等为“三农”问题的研究热点,有关农民、农民工的论文最受关注且被引频次最高.  相似文献   
223.
以兰州市洒水车治污政策为研究案例,应用清晰集定性比较分析法(Crisp-set QCA)研究地方政府具体环保政策的变迁问题。分析发现,自上而下的政治压力、公众舆论压力、媒介压力、专家压力以及领导变更等五类8个解释变量可以作为案例政策变迁的驱动因素,其中,中央媒介压力是政策变迁的必要条件。按照不同的驱动因素组合,兰州洒水治污政策变迁有4种演进路径,其中,最短路径是“中央媒介压力且网络媒介压力”与“领导批示且中央媒介压力”。此外,在本政策案例中,领导批示不但没有促成政策变迁,甚至不构成变迁的必要条件。无论是“地方领导留言板”,还是“门户网站留言板”均非政策变迁的充分或必要条件,因此未能彰显公民参与在政策问题建构中的权力扩大,公众并没有实质拥有建构权,也未能成为建构主体,仅依赖互动平台的构建是无法打破原有的政策问题建构秩序的,因而也不能促使政策变迁彰显民意。  相似文献   
224.
为了开发大型贯流式水轮发电机组径向轴承,在试验台上采用了360的模型轴承对1740可倾6瓦块原型轴承进行模拟试验研究,最高试验比压3.37 MPa、最低线速度3.77 m/s、最高线速度22.62 m/s。试验表明:载荷、进油压力、转速、进油温度和安装间隙比等,对轴承油温升、油流量、功耗、瓦温及油膜厚度等都存在不同程度的影响,其中载荷和转速的影响比较显著。按照模型轴承指导设计的红岩子机组1740轴承已在电站可靠运行,同时开发了径向轴承热弹流计算程序,可以预测径向轴承的油膜压力、油膜温度、油膜厚度、损耗、流量等参数。  相似文献   
225.
This article compares state policies to support childcare in Japan, South Korea and Taiwan, using fuzzy set ideal type analysis to determine the nature of institutional arrangements with respect to labour, money and time provisions. We then note their implications for familialization and defamilialization in the three countries. Our analysis suggests a common pattern towards the increased use of financial support amongst the three countries over time; however, this commonality does not mean their childcare policies are converging, as the financial supports differ in focus, with Japan concentrating on familialization by valuing family care, and Korea exclusively employing policy to facilitate the use of market‐based care services. For its part, Taiwan has been strengthening familialization by increasing the leave compensation to value time off to provide care. The different labour, money and time dimensions vis‐à‐vis the familialization/defamilialization matrix suggest varying implications of institutional arrangements for gender.  相似文献   
226.
The evaluation of hazards from complex, large scale, technologically advanced systems often requires the construction of computer implemented mathematical models. These models are used to evaluate the safety of the systems and to evaluate the consequences of modifications to the systems. These evaluations, however, are normally surrounded by significant uncertainties related to the uncertainty inherent in natural phenomena such as the weather and those related to uncertainties in the parameters and models used in the evaluation.

Another use of these models is to evaluate strategies for improving information used in the modeling process itself. While sensitivity analysis is useful in defining variables in the model that are important, uncertainty analysis provides a tool for assessing the importance of uncertainty about these variables. A third complementary technique, is decision analysis. It provides a methodology for explicitly evaluating and ranking potential improvements to the model. Its use in the development of information gathering strategies for a nuclear waste repository are discussed in this paper.  相似文献   
227.
In risk assessment, the moment‐independent sensitivity analysis (SA) technique for reducing the model uncertainty has attracted a great deal of attention from analysts and practitioners. It aims at measuring the relative importance of an individual input, or a set of inputs, in determining the uncertainty of model output by looking at the entire distribution range of model output. In this article, along the lines of Plischke et al., we point out that the original moment‐independent SA index (also called delta index) can also be interpreted as the dependence measure between model output and input variables, and introduce another moment‐independent SA index (called extended delta index) based on copula. Then, nonparametric methods for estimating the delta and extended delta indices are proposed. Both methods need only a set of samples to compute all the indices; thus, they conquer the problem of the “curse of dimensionality.” At last, an analytical test example, a risk assessment model, and the levelE model are employed for comparing the delta and the extended delta indices and testing the two calculation methods. Results show that the delta and the extended delta indices produce the same importance ranking in these three test examples. It is also shown that these two proposed calculation methods dramatically reduce the computational burden.  相似文献   
228.
The present study uses the concept of technological efficacy derived from ecological psychology and design studies to offer an alternative way of analyzing how policy instruments affect change. Reasoning from this, the paper outlines a framework for analyzing policy instruments in terms of their affordances. We define affordances as the means through which an instrument exerts influence on its intended target audience. Using this approach, we contend that policy instruments may be analyzed as interfaces that organize social relations and create structures of opportunity and/or restrict possibilities for action. We argue that explicating the pathways through which instruments afford or constrain action is a central task for policy analysis. Our proposed framework of analysis builds on the idea that instruments yield effects by facilitating action and learning. We further contend that the actions that an instrument can facilitate or inhibit are determined by specific affordance modalities of the instrument in conjunction with contingencies of the actor and the policy environment. Examples from research policy are used to illustrate some of these effects.  相似文献   
229.
煤矿瓦斯爆炸事故单危险源风险度量模型研究   总被引:1,自引:0,他引:1  
本文研究了煤矿瓦斯爆炸事故危险源的分类,把危险源划分为人的不安全行为、机器设备不安全状态、环境不安全特征和管理缺陷四大类,并根据煤矿现场调查各类危险源的数据以及相应数学方法的特点,提出煤矿瓦斯爆炸事故人、机器设备(物)、环境、管理四类危险源的风险度量方法,在此基础上构建四类危险源的风险度量模型。研究表明,危险源的风险度量模型由风险发生的可能性、危险源重要度以及事故导致的损失构成;危险源风险发生的可能性,在具体应用中可以采用各类危险源的不可靠度、故障率等来衡量;危险源在事故中的重要度可以通过分析事故故障树种要素结构重要性获取。根据风险评价的结果,可以对危险源进行分级排序,从而为煤矿事故单危险源的控制提供依据。  相似文献   
230.
Economic issues linked to career counseling are a cause for concern to policy makers in developed countries because they expect career practitioners to provide evidence of the efficiency of career counseling interventions. The aim of this study was to test an individual evaluation method mixing time series (outcomes) and life narrative (processes). The method used 5 items related to 1 client's career decision self‐efficacy and studied the evolution of those items throughout the intervention of 1 career counselor (43 days). Changepoint analysis helped in identifying the changes that have to be taken into account for time series and which are contextualized in the client's verbatim analysis. This mixed method highlighted that the career counselor's intervention increased the client's career decision self‐efficacy. Practitioners could use the methodology proposed in this article to evaluate their interventions. They could also report their practice to clients, employers, and decision makers.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号