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   126篇
  免费   2篇
各国政治   4篇
工人农民   3篇
世界政治   11篇
外交国际关系   5篇
法律   72篇
政治理论   16篇
综合类   17篇
  2021年   2篇
  2020年   1篇
  2019年   4篇
  2018年   1篇
  2017年   1篇
  2016年   5篇
  2015年   1篇
  2014年   1篇
  2013年   20篇
  2012年   5篇
  2011年   10篇
  2010年   8篇
  2009年   9篇
  2008年   7篇
  2007年   5篇
  2006年   6篇
  2005年   6篇
  2004年   5篇
  2003年   5篇
  2002年   1篇
  2000年   1篇
  1998年   2篇
  1997年   1篇
  1993年   2篇
  1992年   1篇
  1991年   3篇
  1990年   3篇
  1987年   1篇
  1985年   1篇
  1984年   1篇
  1981年   1篇
  1979年   1篇
  1978年   2篇
  1976年   1篇
  1974年   1篇
  1972年   2篇
  1968年   1篇
排序方式: 共有128条查询结果,搜索用时 15 毫秒
121.
The Maxcan fibre finder system is a product of Cox Analytical Systems, Sweden, and has been developed for the primary purpose of searching for fibres on tape lifts. This paper evaluates the ability of the Maxcan system to search for different fibre types and colours under varying conditions. The system performed effectively in most situations, although it did have problems with some search combinations that a human operator would also find difficult in a manual search. The Maxcan system has the added advantages of being objective, consistent and able to do large batch searches unattended. These attributes make it very useful where a large number of tapes need to be searched in casework and also in research where large quantities of data need to be gathered within a reasonable time.  相似文献   
122.
This study investigated the application of chemical imaging to the detection of latent fingerprints using the Condor macroscopic chemical imaging system (ChemImage Corp., Pittsburgh, USA). Methods were developed and optimised for the visualisation of untreated latent fingerprints and fingerprints processed with DFO, ninhydrin, cyanoacrylate, and cyanoacrylate plus rhodamine 6G stain. The results obtained with chemical imaging were compared to the detection achieved using conventional imaging techniques. The Condor significantly improved the detection of many prints, especially those that might be considered poor quality or borderline prints. Prints on newspaper treated with ninhydrin and DFO, and prints on white and yellow paper treated with ninhydrin, benefited the most from chemical imaging detection. In many cases, fingerprints undetectable using conventional imaging techniques could be visualised with chemical imaging. Ridge detail from untreated prints on yellow paper was also detected using the Condor. When prints of high quality were examined, both detection techniques produced quality results. The results of this project demonstrate that chemical imaging offers advantages over conventional visualisation techniques when examining latent fingerprints, especially those that would be considered difficult, such as weak prints or prints on surfaces that produce highly luminescent backgrounds. Standard testing procedures for the detection and enhancement of fingerprints by chemical imaging are presented and discussed.  相似文献   
123.
124.
HIV-negative, inner-city adolescents with HIV-infected parents are considered to be at high risk for acquiring HIV themselves. Using a modified theory of health behavior, this study examined the effects of maternal HIV infection and psychosocial variables on the onset of sexual and drug risk behavior in 144 HIV-negative adolescents with and without HIV-positive mothers. Adolescents and their mothers were interviewed when the youths were 10–14 years old and again when they were 13–19 years old. By follow-up, 42% of youths reported the onset of vaginal sex (vs 5% at baseline). Marijuana and alcohol use increased from 6 and 38%, respectively, at baseline to 25 and 60% at follow-up. Among those reporting risk behaviors, 40--50% reported onset prior to 14 years. Youth and family psychosocial variables, but not maternal HIV status, were associated with risk behaviour outcomes. Claude A. Mellins research interests include mental health, psychosocial, and public effects of maternal and pediatric HIV; interventions for HIV-affected families; and adherence. Curtis Dolezal research interests include HIV-related sexual behavior in a variety of populations with a particular emphasis on methodology/measurement issues. Elizabeth Brackis-Cott research interests include impact of HIV/AIDS on the lives of children and families directly affected by the disease. Ouzama Nicholson research interests include international public health and pediatric HIV infection and operational issues in developing effective prevention of mother-to-child transmission of HIV infection and pediatric HIV care programs. Patricia Warne research interests include program development, structural interventions for HIV, and policy. Heino F. L. Meyer-Bahlburg research interests include psychosexual assessment, the development and determinants of sexual risk behavior, and the effects of HIV disease on sexual functioning.  相似文献   
125.
A manner of death may be ruled undetermined by the forensic pathologist when there is insufficient information about the circumstances surrounding the death to make a ruling. The aim of our study was to retrospectively analyze a series of autopsy cases that were classified as undetermined manner of death after complete investigations. In all, 48 cases were examined. In 23 cases (48%), the cause of death was determined. The most frequent cause of death was toxic death (n = 11). More than one manner of death was deemed conceivable for most cases (n = 39). The most frequent and the most probable manner of death was accident (n = 37). Homicide was not excluded in about 23% of the cases. Our study showed that the manner of death may remain undetermined despite an established cause of death, and even when two or more conceivable causes of death are considered. Our study pointed out that undetermined manner of death covers a wide range of situations and that homicide may be underestimated.  相似文献   
126.
This article assesses the impact of New Public Management (NPM) reforms in the public sector from a cost consciousness perspective. Using an action‐research methodology, we analyze the intensity of the external pressures that influence the institutional logic under which public sector organizations manage their costs. The field work shows that even after decentralization, public sector organizations appear unable to move their costing function from expense control to cost management unless external pressures motivate managers to complete the reform. We propose that the probability of success of reforms is increased when organizations are subject to strong pressures that could take the form of individual incentives or external threats.  相似文献   
127.
Technology Transfer to China The Issues of Knowledge and Learning   总被引:1,自引:0,他引:1  
The aspect of effectiveness of technology transfer to developing countries still raises important questions from researchers and practitioners alike. Many of these questions pertain to the nature of knowledge and of the learning process. The first question for this paper is what forms of knowledge are transferred abroad by companies. The second question is what are the characteristics of the learning process in recipient firms during technology transfer. Twenty-eight Canadian manufacturing firms were interviewed. Seven case studies were also conducted in China.Our results demonstrate that tacit knowledge constitutes a substantial part of the total knowledge transferred by Canadian firms to China. The nonexplicit nature of knowledge leaves room for numerous problems of interpretation, not only at the technical and managerial level, but also at the more global level of national culture and institutions. Our findings tend to validate the evolutionary and cognitivistic positions on the nature of knowledge. The results also partly confirm our sequential model of learning.  相似文献   
128.
Through an innovative public-private partnership, Demeter Agricultural Limited, along with the Malawi National Bean Programme and the International Center for Tropical Agriculture, supplied 2,559 tons of certified bean seed between 2009 and 2012 through the government's Targeted Farm Input Programme. Farmers were satisfied with the variety supplied, timeliness of the operation, pack size, and information provided. Growing numbers also accessed new improved varieties, from 264,661 households in 2009 to 344,200 in 2012. These emerging farmers’ demands and the subsequent DAL responses suggest a base for building sustainable delivery systems. However, decentralised seed-based systems will be needed for promoting varieties suited to micro-ecological niches.  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