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   39083篇
  免费   802篇
  国内免费   1篇
管理学   5732篇
民族学   212篇
人才学   2篇
人口学   5163篇
丛书文集   136篇
教育普及   3篇
理论方法论   3132篇
现状及发展   2篇
综合类   665篇
社会学   18248篇
统计学   6591篇
  2023年   163篇
  2021年   187篇
  2020年   446篇
  2019年   621篇
  2018年   2222篇
  2017年   2459篇
  2016年   1742篇
  2015年   574篇
  2014年   755篇
  2013年   4818篇
  2012年   1290篇
  2011年   1961篇
  2010年   1654篇
  2009年   1356篇
  2008年   1464篇
  2007年   1656篇
  2006年   669篇
  2005年   896篇
  2004年   883篇
  2003年   778篇
  2002年   738篇
  2001年   778篇
  2000年   780篇
  1999年   682篇
  1998年   506篇
  1997年   463篇
  1996年   482篇
  1995年   455篇
  1994年   397篇
  1993年   414篇
  1992年   482篇
  1991年   439篇
  1990年   411篇
  1989年   435篇
  1988年   422篇
  1987年   370篇
  1986年   374篇
  1985年   425篇
  1984年   409篇
  1983年   378篇
  1982年   321篇
  1981年   266篇
  1980年   253篇
  1979年   318篇
  1978年   261篇
  1977年   238篇
  1976年   207篇
  1975年   225篇
  1974年   184篇
  1973年   177篇
排序方式: 共有10000条查询结果,搜索用时 125 毫秒
911.
Over the last fifteen years companies tended to formalise their innovation management activities and to establish formal jobs like the innovation officer, the network manager or the innovation manager. Knowledge of the informal role profiles of these formal roles is still rare. HR and R&D Managers do not know which informal role profile might suit them best, thus having difficulties to assign the best candidates for jobs in innovation management. Researchers cannot help to resolve the problem. Our research answers the question what innovation managers really do, by analysing their tasks, skills and traits, theoretically based on informal role theories. Furthermore, we will analyse how these characteristics change with company size. To provide answers to our research questions we choose a multiple-case study approach. We found, among others, that innovation managers fulfil the role of the relationship and process promotor or a combination of both with the champion, but we also found, that the innovation manager’s roles profile becomes fuzzier with shrinking company size. Our results have practical implications for top management and also HR and R&D managers, enabling them to better select and steer employees in innovation management. Researchers will be able to build on our results because we offer a comprehensive understanding of the informal role profiles of innovation managers based on informal role theories.  相似文献   
912.
From its beginnings research on social indicators was not primarily considered as pure, but rather applied research in terms of the regular monitoring of and reporting on quality of life. Thus, the successes—but eventually also failures—of social indicators research may first of all be visible in its most important field of application. Social monitoring and reporting activities, which can be traced back to the early 1970s provide quantitative information and empirically based analytical knowledge on well-being and progress in a single society or groups of societies to be used for different purposes, including policy making. Providing an overview over the variety of social monitoring and reporting projects emerging from social indicators research is supposed to be important with a view to form a more solid fundament for present and future discourses and initiatives in the field of measuring and monitoring well-being and progress. The article looks back to this field of applied social indicators research and—with a focus on Europe—identifies patterns and recent trends in this sort of activities. By looking forward, it finally discusses selected issues that are considered to be crucial for further improvements in this field.  相似文献   
913.
In electronics Fabs such as semiconductor Fabs and liquid crystal display (LCD) Fabs, which are capital-intensive, finite-capacity planning is critical to achieving full-capacity production and on-time production. However, existing finite-capacity planning methods do not adequately reflect the actual capacity profiles of an electronics Fab. In this paper, we propose a new Fab-level capacity-filtering procedure to generate finite-capacity plan: a backward capacity-filtering procedure for generating finite-capacity release plan. When developing the Fab-level filtering procedures, we use stage-level capacity-filtering algorithms as a key building block. In this study, we enhance the previous capacity-filtering algorithms proposed by one of the authors in order to facilitate the practical requirements of electronics Fabs. We apply the proposed capacity-filtering method to a modern LCD–TFT Fab in Korea. Performance analyses demonstrate that the proposed method is superior to existing methods.  相似文献   
914.
The Bayesian paradigm provides an ideal platform to update uncertainties and carry them over into the future in the presence of data. Bayesian predictive power (BPP) reflects our belief in the eventual success of a clinical trial to meet its goals. In this paper we derive mathematical expressions for the most common types of outcomes, to make the BPP accessible to practitioners, facilitate fast computations in adaptive trial design simulations that use interim futility monitoring, and propose an organized BPP-based phase II-to-phase III design framework.  相似文献   
915.
The professional decision-making in research (PDR) measure was administered to 400 National Institutes of Health (NIH)-funded and industry-funded investigators, along with measures of cynicism, moral disengagement, compliance disengagement, impulsivity, work stressors, knowledge of responsible conduct of research (RCR), and socially desirable response tendencies. Negative associations were found for the PDR and measures of cynicism, moral disengagement, and compliance disengagement, while positive associations were found for the PDR and RCR knowledge and positive urgency, an impulsivity subscale. PDR scores were not related to socially desirable responding, or to measures of work stressors and the remaining impulsivity subscales. In a multivariate logistic regression analysis, lower moral disengagement scores, higher RCR knowledge, and identifying the United States as one’s nation of origin emerged as key predictors of stronger performance on the PDR. The implications of these findings for understanding the measurement of decision-making in research and future directions for research and RCR education are discussed.  相似文献   
916.
Elasticity (or elasticity function) is a new concept that allows us to characterize the probability distribution of any random variable in the same way as characteristic functions and hazard and reverse hazard functions do. Initially defined for continuous variables, it was necessary to extend the definition of elasticity and study its properties in the case of discrete variables. A first attempt to define discrete elasticity is seen in Veres-Ferrer and Pavía (2014a). This paper develops this definition and makes a comparative study of its properties, relating them to the properties shown by discrete hazard and reverse hazard, as both defined in Chechile (2011). Similar to continuous elasticity, one of the most interesting properties of discrete elasticity focuses on the rate of change that this undergoes throughout its support. This paper centers on the study of the rate of change and develops a set of properties that allows us to carry out a detailed analysis. Finally, it addresses the calculation of the elasticity for the resulting variable obtained from discretizing a continuous random variable, distinguishing whether its domain is in real positives or negatives.  相似文献   
917.
918.
Since decades, the financial industry has experienced a continuous evolution in service delivery due to digitalization. This evolution is characterized by expanded connectivity and enhanced speed of information processing both at the customer interface and in back-office processes. Recently, there has been a shift in the focus of digitalization from improving the delivery of traditional tasks to introducing fundamentally new business opportunities and models for financial service companies. Digital Finance encompasses a magnitude of new financial products, financial businesses, finance-related software, and novel forms of customer communication and interaction—delivered by FinTech companies and innovative financial service providers. Against this backdrop, the research on finance and information systems has started to analyze these changes and the impact of digital progress on the financial sector. Therefore, this article reviews the current state of research in Digital Finance that deals with these novel and innovative business functions. Moreover, it gives an outlook on potential future research directions. As a conceptual basis for reviewing this field, the Digital Finance Cube, which embraces three key dimensions of Digital Finance and FinTech, i.e., the respective business functions, the technologies and technological concepts applied as well as the institutions concerned, is introduced. This conceptualization supports researchers and practitioners when orientating in the field of Digital Finance, allows for the arrangement of academic research relatively to each other, and enables for the revelation of the gaps in research.  相似文献   
919.
920.
Several colorectal cancer (CRC) screening models have been developed describing the progression of adenomas to CRC. Currently, there is increasing evidence that serrated lesions can also develop into CRC. It is not clear whether screening tests have the same test characteristics for serrated lesions as for adenomas, but lower sensitivities have been suggested. Models that ignore this type of colorectal lesions may provide overly optimistic predictions of the screen‐induced reduction in CRC incidence. To address this issue, we have developed the Adenoma and Serrated pathway to Colorectal CAncer (ASCCA) model that includes the adenoma‐carcinoma pathway and the serrated pathway to CRC as well as characteristics of colorectal lesions. The model structure and the calibration procedure are described in detail. Calibration resulted in 19 parameter sets for the adenoma‐carcinoma pathway and 13 for the serrated pathway that match the age‐ and sex‐specific adenoma and serrated lesion prevalence in the COlonoscopy versus COlonography Screening (COCOS) trial, Dutch CRC incidence and mortality rates, and a number of other intermediate outcomes concerning characteristics of colorectal lesions. As an example, we simulated outcomes for a biennial fecal immunochemical test screening program and a hypothetical one‐time colonoscopy screening program. Inclusion of the serrated pathway influenced the predicted effectiveness of screening when serrated lesions are associated with lower screening test sensitivity or when they are not removed. To our knowledge, this is the first model that explicitly includes the serrated pathway and characteristics of colorectal lesions. It is suitable for the evaluation of the (cost)effectiveness of potential screening strategies for CRC.  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