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   4524篇
  免费   271篇
  国内免费   40篇
管理学   395篇
民族学   49篇
人才学   1篇
人口学   255篇
丛书文集   525篇
理论方法论   211篇
综合类   1943篇
社会学   442篇
统计学   1014篇
  2024年   4篇
  2023年   32篇
  2022年   35篇
  2021年   59篇
  2020年   116篇
  2019年   84篇
  2018年   91篇
  2017年   111篇
  2016年   119篇
  2015年   139篇
  2014年   294篇
  2013年   524篇
  2012年   249篇
  2011年   299篇
  2010年   146篇
  2009年   156篇
  2008年   131篇
  2007年   176篇
  2006年   223篇
  2005年   176篇
  2004年   191篇
  2003年   210篇
  2002年   291篇
  2001年   240篇
  2000年   182篇
  1999年   64篇
  1998年   64篇
  1997年   73篇
  1996年   39篇
  1995年   24篇
  1994年   28篇
  1993年   6篇
  1992年   18篇
  1991年   12篇
  1990年   5篇
  1989年   3篇
  1988年   10篇
  1987年   1篇
  1986年   2篇
  1985年   30篇
  1984年   25篇
  1983年   30篇
  1982年   34篇
  1981年   30篇
  1980年   14篇
  1979年   17篇
  1978年   24篇
  1977年   2篇
  1976年   1篇
  1975年   1篇
排序方式: 共有4835条查询结果,搜索用时 15 毫秒
81.
以大样本问卷调查为基础,采用多种数理统计方法,进行基于学习动机主观感知为学生主体类型划分及影响因素的研究。发现学习动机表征因素不止于内在和外在,还会体现在近期和远期、物质和精神、自我和他者等其他复杂要素上,而且还会受到入校时间、学校类型、性别以及地缘背景等因素影响。构建与学生主体需求相匹配的教育资源供给梯次和分类指导对促进高校教育具有重要意义。  相似文献   
82.
I have received substantial monetary compensation and a formal apology from my first doctoral school, and a Ph.D. from another university. This essay describes my personal view on discussing the boundaries of academic judgment and research supervision with the ombudsman agency for higher education, and at the High Administrative Court of England and Wales. The Court’s judicial doctrine addresses substantial research accountability matters. It clarifies that although the Court and ombudsman agency must not interfere with academic judgment, not everything done by an academic can be considered as academic judgment. A Ph.D. supervisor can seriously fail to perform his/her duties.  相似文献   
83.
High-tech research infrastructure is essential for state-of-the-art research, but requires many resources. Relatively weak actors, such as SMEs, cannot secure enough of those. Applying the concept of collaborative consumption via digital platforms, we examine the cooperative behavior of Korean SMEs that share research equipment to overcome their lack of resources. Also, we analyze configurations of a collaborative consumption network using the Exponential Random Graph Model. Network structural factor analysis shows sufficient effects of network positive feedback through cooperative consumption with a variety of popular providers and attributes analysis shows that SMEs frequently engage in collaborative consumption with their counterparts in the same region. This new cooperative model can achieve a virtuous cycle of policies, as it increases the efficiency of research infrastructure, preventing the unnecessary building of new research equipment and enabling relocation of underutilized infrastructure and online reservation of equipment.  相似文献   
84.
In this article, a system that consists of n independent components each having two dependent subcomponents (Ai, Bi), i = 1, …, n is considered. The system is assumed to compose of components that have two correlated subcomponents (Ai, Bi), and functions iff both systems of subcomponents A1, A2, …, An and B1, B2, …, Bn work under certain structural rules. The expressions for reliability and mean time to failure of such systems are obtained. A sufficient condition to compare two systems of bivariate components in terms of stochastic ordering is also presented.  相似文献   
85.
86.
The importance of innovation development is determined by the strategic role that true innovations play in the development of the state and the formation of a healthy, competitive economy. The organization of massive industrial production—which applies advanced technological achievements and science-intensive knowledge to form an infrastructure for innovation—should be a key component of the government’s strategic policy to develop the national economy. In Russia, the infrastructure for innovation is less developed than other industrialized countries. This article considers the consequences of this underdevelopment, and proposes several ways of financing basic and applied research on the basis of foreign precedent and domestic practice.  相似文献   
87.
88.
In late 2009 China launched an innovative, voluntary programme that by 2011 had extended pension coverage to 326.4 million people in the rural sector, including contributors and beneficiaries. It requires one contribution per year and provides a flat‐rate benefit and a contributions‐related benefit through a contributory individual account, with a government guarantee that the benefit will continue for life. The programme encourages participation of persons who do not pay income taxes, and thus have no tax incentive to participate, by providing substantial government subsidies. As a further incentive, old‐age benefits are provided to older parents when all their adult children participate in the contributory programme.  相似文献   
89.
Motivated by classification issues that arise in marine studies, we propose a latent-class mixture model for the unsupervised classification of incomplete quadrivariate data with two linear and two circular components. The model integrates bivariate circular densities and bivariate skew normal densities to capture the association between toroidal clusters of bivariate circular observations and planar clusters of bivariate linear observations. Maximum-likelihood estimation of the model is facilitated by an expectation maximization (EM) algorithm that treats unknown class membership and missing values as different sources of incomplete information. The model is exploited on hourly observations of wind speed and direction and wave height and direction to identify a number of sea regimes, which represent specific distributional shapes that the data take under environmental latent conditions.  相似文献   
90.
Land subsidence risk assessment (LSRA) is a multi‐attribute decision analysis (MADA) problem and is often characterized by both quantitative and qualitative attributes with various types of uncertainty. Therefore, the problem needs to be modeled and analyzed using methods that can handle uncertainty. In this article, we propose an integrated assessment model based on the evidential reasoning (ER) algorithm and fuzzy set theory. The assessment model is structured as a hierarchical framework that regards land subsidence risk as a composite of two key factors: hazard and vulnerability. These factors can be described by a set of basic indicators defined by assessment grades with attributes for transforming both numerical data and subjective judgments into a belief structure. The factor‐level attributes of hazard and vulnerability are combined using the ER algorithm, which is based on the information from a belief structure calculated by the Dempster‐Shafer (D‐S) theory, and a distributed fuzzy belief structure calculated by fuzzy set theory. The results from the combined algorithms yield distributed assessment grade matrices. The application of the model to the Xixi‐Chengnan area, China, illustrates its usefulness and validity for LSRA. The model utilizes a combination of all types of evidence, including all assessment information—quantitative or qualitative, complete or incomplete, and precise or imprecise—to provide assessment grades that define risk assessment on the basis of hazard and vulnerability. The results will enable risk managers to apply different risk prevention measures and mitigation planning based on the calculated risk states.  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