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   487篇
  免费   9篇
  国内免费   2篇
管理学   38篇
民族学   7篇
人口学   12篇
丛书文集   53篇
理论方法论   22篇
综合类   224篇
社会学   85篇
统计学   57篇
  2023年   1篇
  2022年   3篇
  2021年   8篇
  2020年   7篇
  2019年   8篇
  2018年   4篇
  2017年   15篇
  2016年   11篇
  2015年   15篇
  2014年   24篇
  2013年   44篇
  2012年   23篇
  2011年   29篇
  2010年   27篇
  2009年   25篇
  2008年   35篇
  2007年   25篇
  2006年   29篇
  2005年   21篇
  2004年   26篇
  2003年   22篇
  2002年   18篇
  2001年   8篇
  2000年   9篇
  1999年   2篇
  1998年   3篇
  1997年   1篇
  1996年   2篇
  1995年   2篇
  1994年   1篇
  1991年   1篇
  1985年   11篇
  1984年   10篇
  1983年   4篇
  1982年   4篇
  1981年   10篇
  1980年   6篇
  1979年   2篇
  1978年   2篇
排序方式: 共有498条查询结果,搜索用时 15 毫秒
1.
We consider a method of moments approach for dealing with censoring at zero for data expressed in levels when researchers would like to take logarithms. A Box–Cox transformation is employed. We explore this approach in the context of linear regression where both dependent and independent variables are censored. We contrast this method to two others, (1) dropping records of data containing censored values and (2) assuming normality for censored observations and the residuals in the model. Across the methods considered, where researchers are interested primarily in the slope parameter, estimation bias is consistently reduced using the method of moments approach.  相似文献   
2.
嫩江流域发展绿色农业产业集群研究   总被引:5,自引:0,他引:5  
利用SWOT分析工具,以嫩江流域为例,分析绿色农业产业集群的内部优势和劣势以及外部机遇和挑战。嫩江流域发展绿色农业产业集群的途径:按经济区域做好产业发展规划;注重产业关联,促进产业集群发展;以核心企业为龙头,带动主导产业的集群化;发挥政府职能,促进嫩江流域绿色农业产业集群的发展。  相似文献   
3.
为加速发展科学技术, 保持经济上的竞争力和国家安全, 以色列政府从 2 0世纪 6 0年代开始制定并实施了一系列特殊的科学技术政策, 经过几十年的努力, 不仅把以色列变成了一个巨大的科技园区, 而且在一些科技领域已处于世界领先地位。以色列在促进科学技术发展方面所采取的一些政策及措施值得我们研究与借鉴。  相似文献   
4.
本文整合社会网络理论、注意力基础观和新制度主义理论等,通过对282家制造企业的问卷调查,采用多元回归分析方法,探讨了网络密度和高管注意力配置的交互匹配对企业绿色创新的影响机制,以及制度压力在其中的调节作用。研究发现,在高密度网络中,高管采用注意力聚集策略对绿色创新有显著正向影响;而在低密度网络中,高管采用注意力分散策略对绿色创新有显著正向影响。规制压力和模仿压力均正向调节网络密度和高管注意力配置的交互作用对绿色创新的影响,但模仿压力的调节作用更强。通过构建不同制度压力情景下网络密度与高管注意力的交互作用对绿色创新影响的理论框架,本文推动社会网络理论、注意力基础观等成熟的理论成果从一般创新向绿色创新研究领域繁衍,为企业绿色创新加入与主流理论的对话做了努力,为企业在绿色创新过程中根据不同的制度压力,以及所嵌入的组织间网络密度情况,选择合适的注意力配置策略提供理论参考。  相似文献   
5.
5he purpose of this study was to determine whether or not suspected variables affected a surgery clerk's chances of being awarded an honor rating. Findings indicated a significant relationship between a student receiving an honor rating and his or her preceptor's predetermined level of student advocacy, the number of completed patient interview and physical examination write-ups, and final examination scores. There was no significant relationship found between honor ratings and the preceptor's status, the sequence in which the student was discussed or the length of time spent discussing the student at the final evaluation meeting, or the number of clinical faculty present at the meeting. These results lend support to the faculty forum evaluation approach, but suggest a need for further scrutiny of some influencing variables to ensure all students are fairly considered and honor ratings judiciously awarded.  相似文献   
6.
Public policy decisions in health are increasingly difficult and expensive. Although there will never be enough information available, private foundations can help to bridge the most important gaps in knowledge. Larger foundations may also wish to respond to those who doubt the value of foundation activities. This article reviews the experiences over the past eight years of The Robert Wood Johnson Foundation in employing evaluation and related social research procedures in the planning and implementation of a major philanthropic effort to improve the health and medical care of Americans. Discussed are the still evolving Foundation evaluation framework, the unanticipated problems in undertaking specific evaluations, and the substantive findings of some of the studies.  相似文献   
7.
Network analysis, a methodology derived from general systems' theory, can be utilized as a community mental health administrative-evaluation procedure. Evaluation parameters derived from analysis of patient data as they “flow” through a network of agency services, provide measures of systemic functioning. These parameters include “longest paths” and various ratio relationships as evaluation measures of service delivery. The limitations of network analysis are examined by means of conceptual analyses, and phenomena that emerged from research experience. The necessity for both quantitative and qualitative data to ensure a meaningful evaluation of mental health services is explained. Conclusions about the value of the network analysis approach are considered.  相似文献   
8.
Population-to-practitioner ratios have long been the primary index in the designation of health manpower shortage areas. This paper documents that application of the widely used population-to-dentist index results in understatement of the need for dental health manpower in rural areas. Through the analysis of utilization data collected from a statewide health screening program in Colorado, the practice of sole reliance on the population-to-dentist indices as an indicator of need was tested. Another measure, the area-(square miles) to-dentist ratio was formulated, examined, and found to be a more useful referent of the need for additional health manpower in rural areas. Utilization of dental services in sparsely settled rural counties of Colorado was unrelated to population-to-dentist ratios. A strong, statistically significant association of utilization with land area-to-dentist ratios was found. The findings of this analysis suggest a need for reevaluation of needs assessment methodologies used in the designation of health manpower shortage areas. Indices more sensitive to consumer circumstance than to the number of health care providers available must be considered.  相似文献   
9.
Restraining the negative environmental impacts of the construction sector constitutes one of the major challenges of the twenty-first century. However, efforts to address it have been largely fragmented. With environmental consequences of a construction project typically dispersed across its life cycle, i.e. from design through to end-of-life, greening this sector requires a supply chain wide focus inclusive of all key stages and stakeholders; also, all relevant aspects such as the nature of green practices implemented and associated drivers, barriers and performance implications need to be considered. This forms the focus of the present study where a comprehensive, green supply chain management oriented understanding of the construction sector is developed through the context of the UAE construction sector, and incorporating inputs from all key stakeholders, i.e. Developers, Architects/Consultants, Contractors and (material) Suppliers. The study contributes to improving the efficiency and effectiveness of greening of the construction sector.  相似文献   
10.
Box–Cox together with our newly proposed transformation were implemented in three different real world empirical problems to alleviate noisy and the volatility effect of them. Consequently, a new domain was constructed. Subsequently, universe of discourse for transformed data was established and an approach for calculating effective length of the intervals was then proposed. Considering the steps above, the initial forecasts were performed using frequently used fuzzy time series (FTS) methods on transformed data. Final forecasts were retrieved from initial forecasted values by proper inverse operation. Comparisons of the results demonstrate that the proposed method produced more accurate forecasts compared with existing FTS on original data.  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