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   14634篇
  免费   827篇
  国内免费   135篇
管理学   1521篇
劳动科学   2篇
民族学   115篇
人才学   1篇
人口学   384篇
丛书文集   952篇
理论方法论   511篇
综合类   8361篇
社会学   1187篇
统计学   2562篇
  2024年   13篇
  2023年   128篇
  2022年   107篇
  2021年   154篇
  2020年   289篇
  2019年   332篇
  2018年   375篇
  2017年   469篇
  2016年   417篇
  2015年   491篇
  2014年   799篇
  2013年   1562篇
  2012年   1046篇
  2011年   1033篇
  2010年   827篇
  2009年   783篇
  2008年   900篇
  2007年   984篇
  2006年   911篇
  2005年   790篇
  2004年   688篇
  2003年   575篇
  2002年   480篇
  2001年   352篇
  2000年   261篇
  1999年   149篇
  1998年   82篇
  1997年   86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   24篇
  1987年   23篇
  1986年   21篇
  1985年   14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 15 毫秒
81.
This study presents probabilistic analysis of dam accidents worldwide in the period 1911–2016. The accidents are classified by the dam purpose and by the country cluster, where they occurred, distinguishing between the countries of the Organization for Economic Cooperation and Development (OECD) and nonmember countries (non-OECD without China). A Bayesian hierarchical approach is used to model distributions of frequency and severity for accidents. This approach treats accident data as a multilevel system with subsets sharing specific characteristics. To model accident probabilities for a particular dam characteristic, this approach samples data from the entire data set, borrowing the strength across data set and enabling to model distributions even for subsets with scarce data. The modelled frequencies and severities are combined in frequency-consequence curves, showing that accidents for all dam purposes are more frequent in non-OECD (without China) and their maximum consequences are larger than in OECD countries. Multipurpose dams also have higher frequencies and maximum consequences than single-purpose dams. In addition, the developed methodology explicitly models time dependence to identify trends in accident frequencies over the analyzed period. Downward trends are found for almost all dam purposes confirming that technological development and implementation of safety measures are likely to have a positive impact on dam safety. The results of the analysis provide insights for dam risk management and decision-making processes by identifying key risk factors related to country groups and dam purposes as well as changes over time.  相似文献   
82.
The 4-A Framework suggests that all inclusive education systems must be available, accessible, acceptable and adaptable. South Africa is committed to establishing an inclusive education system that does not exclude students with disabilities. South African university disability policies translate the imperatives of the United Nations Convention on the Rights of Persons with Disabilities into institutional mandates that govern the implementation of inclusive education. The aim of this study was to determine to what extent disability policies at South African research-intensive universities addressed the markers contained in the 4-A Framework. The framework was reworked and operationalised for the higher education context, and expanded to include a fifth marker, namely affordability. A deductive thematic analysis, using a protocol based on the five markers, was used to analyse these policies. Results indicate that, of the five markers, affordability was not sufficiently addressed. Various disclaimers also limit policy provisions related to other markers.  相似文献   
83.
Research on the role of social networks in human migration has mainly relied on single snapshots in time. This paper focuses on the changes in composition and usage of the transnational networks of migrants and why these changes occur. It is based on ethnography and network analysis with forty sub-Saharan African migrants in two transit contexts: Turkey and Greece, over a 17-month period. Findings show that relationship preferences, resources and communication infrastructures constitute an individual opportunity infrastructure affecting how critical events produce network changes. This process is ongoing through the continued experience of critical events, suggesting that the role of networks fluctuates over time.  相似文献   
84.
[Purpose/Significance] This article provides a bibliometric study of the big data research literature in social science to explore its features and patterns both in domestic and international area, quantitatively and qualitatively. [Method/Process] This article collects the data from academic databases, then makes statistical analysis on significant characteristics to evaluate the regularity of document increase, distribution of subject categories, most prolific and impactful institutions, and then discusses the relations between research front and intellectual base via citation and co-citation analysis, finally concludes research features and patterns of big data. [Result/Conclusion] (1) Different subject categories show the different level of research interest while big data research has been one of the most popular topics in social science. The most documents are from information science and library science. (2) Besides journals of high output subject categories, computer science, telecommunications and multidisciplinary journals are common intellectual bases of big data research in social science. (3) Renmin University of China in domestic and Harvard University in the world are top institutions according to the number of fruits and influence of their publications of big data research in social science. (4) For China, publication quantity in social science makes apparent growth while international academic influence is still limited.  相似文献   
85.
We derive explicit formulas for Sobol's sensitivity indices (SSIs) under the generalized linear models (GLMs) with independent or multivariate normal inputs. We argue that the main-effect SSIs provide a powerful tool for variable selection under GLMs with identity links under polynomial regressions. We also show via examples that the SSI-based variable selection results are similar to the ones obtained by the random forest algorithm but without the computational burden of data permutation. Finally, applying our results to the problem of gene network discovery, we identify through the SSI analysis of a public microarray dataset several novel higher-order gene–gene interactions missed out by the more standard inference methods. The relevant functions for SSI analysis derived here under GLMs with identity, log, and logit links are implemented and made available in the R package Sobol sensitivity.  相似文献   
86.
The product limit or Kaplan‐Meier (KM) estimator is commonly used to estimate the survival function in the presence of incomplete time to event. Application of this method assumes inherently that the occurrence of an event is known with certainty. However, the clinical diagnosis of an event is often subject to misclassification due to assay error or adjudication error, by which the event is assessed with some uncertainty. In the presence of such errors, the true distribution of the time to first event would not be estimated accurately using the KM method. We develop a method to estimate the true survival distribution by incorporating negative predictive values and positive predictive values, into a KM‐like method of estimation. This allows us to quantify the bias in the KM survival estimates due to the presence of misclassified events in the observed data. We present an unbiased estimator of the true survival function and its variance. Asymptotic properties of the proposed estimators are provided, and these properties are examined through simulations. We demonstrate our methods using data from the Viral Resistance to Antiviral Therapy of Hepatitis C study.  相似文献   
87.
Since summer 2014, the insurgent group ‘Islamic State in Iraq and Syria’ (ISIS) has become a major concern for international politics and global security due to its rapid territorial gains, violent operations and the propagation of Salafi-jihadist ideology. This study aims to enhance the academic understanding of ISIS by demystifying the ideological reasoning behind its use of violence. It therefore investigates the link between structural factors that served ISIS’s evolution, its ideological outlook and the significance of this ideology to legitimize violent action. As its theoretical basis, the study employs framing processes within the study of social movements. Methodologically, discursive frame analysis serves to explore the relation of ISIS’s ideology to structural events and experiences to better understand how the group justifies violence. Therefore, the study draws on audio speeches and issues of the magazines Dabiq and Dar al-Islam published by ISIS, which are examined on the rhetoric of othering, collective identity and justifying violence. It is argued that ISIS constructs a collective action frame which creates a social reality that bestows the group with a rationale for action. ISIS’s ideology, based on Islamic symbolism, presents an interpretative lens which assigns meaning to the structural environment of ISIS’s emergence. In this context, violence is justified as a necessity to defend Islam and as an obligation for the true Muslim believer. The discussion concludes that ISIS’s ideology legitimizes the very existence of the group and conceals its mundane struggle for power, territory and wealth through reference to divine authority.  相似文献   
88.
We analysed narratives of motherhood produced by 13 women who were involved with the welfare system or the justice system during adolescence. The original contribution of our study was its focus on mothers who were turning age 30, so they were not in that period of generalized instability that characterizes the transition from care and into adulthood. This qualitative study was part of a larger study on French‐Canadian adolescents with a history of residential care. Semi‐directed interviews were conducted with 13 women, more than 15 years after their admission to residential care. Our data highlights that motherhood can contribute to the vulnerability of women who were involved with the welfare or the justice system as adolescents. Our results suggest that in order to shed a perceived deviant label and to compensate for the adverse events they experienced, they pursue internalized ideals of “good motherhood” that translate into restrictions and strain. Furthermore, they tend to refrain from allowing people into their lives and asking for help for fear of being judged. Yet, as their children are getting older and exhibiting problem behaviors of their own, the questioning of their parental practices and skills only becomes more intense.  相似文献   
89.
ABSTRACT

We consider action research as a form of deliberative policy analysis. This analysis explores a “reconstruction clinic” in which stakeholders and public officials engaged memories, hopes and obligations as they sought to resolve controversies over details of policy implementation. We ask how institutional design shaped participants’ reflective and deliberative progress. Reflection in action can prompt not only changes in cognitive frames, but new behavioural capacities for action. Deliberative practices can shape new relationships between parties through the work of apology, recognition, appreciation, and emergent collaboration.  相似文献   
90.
石油本身没有政治属性,但由石油衍生的占有权、控制权以及资源开发与利用、价格制定等因素则与国际政治经济关系密切。近年来,对外能源高依存度一直威胁着中国的能源安全并对我国经济社会发展产生着潜在的影响。沙特作为世界上石油储藏量与出口量大国之一,对满足中国能源需求意义重大。中沙具有良好的合作基础以及互补的能源战略,在能源合作方面具有广阔的前景。受国际政治经济因素的影响,中沙能源合作的主要影响因素来自美国、俄罗斯、印度和伊朗。为了保障中国的能源安全,需要进一步强化中沙能源合作力度,当前可以采取的措施主要包括:强化中沙能源领域的金融合作,建立双边制度性合作框架,协助沙特保障国家安全,与沙特和伊朗等国保持紧密的双边关系,等等。  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