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   406篇
  免费   21篇
各国政治   13篇
工人农民   44篇
世界政治   23篇
外交国际关系   9篇
法律   223篇
中国政治   5篇
政治理论   104篇
综合类   6篇
  2024年   1篇
  2023年   6篇
  2022年   2篇
  2021年   4篇
  2020年   12篇
  2019年   15篇
  2018年   18篇
  2017年   10篇
  2016年   19篇
  2015年   17篇
  2014年   8篇
  2013年   54篇
  2012年   18篇
  2011年   16篇
  2010年   8篇
  2009年   16篇
  2008年   26篇
  2007年   22篇
  2006年   13篇
  2005年   14篇
  2004年   9篇
  2003年   19篇
  2002年   3篇
  2001年   8篇
  2000年   5篇
  1999年   3篇
  1998年   5篇
  1997年   3篇
  1996年   5篇
  1995年   3篇
  1994年   5篇
  1993年   6篇
  1992年   5篇
  1989年   5篇
  1988年   3篇
  1987年   6篇
  1986年   12篇
  1985年   9篇
  1984年   2篇
  1983年   2篇
  1982年   3篇
  1981年   2篇
  1980年   2篇
  1979年   2篇
  1976年   1篇
排序方式: 共有427条查询结果,搜索用时 46 毫秒
411.
The questioned document laboratory is often called upon to decipher writing that has been erased, obliterated, or that has faded. In cases like these, the original writing is no longer legible to the naked eye, but may be enhanced using various light sources. Certain remnants of the ink's components absorb into the substrate's fibers and can be visualized, usually as luminescence or absorbance. A case is described here that involved the theft of a credit card. An empty plastic credit card holder was found in the possession of a suspect, and as submitted for examination. Indented impressions could be discerned on its clear plastic window and presumably originated from the credit card that had been held in the envelope. These indented impressions were deciphered in the hope that they would reveal enough details from the credit card to establish a connection between the plastic envelope and the stolen credit card. With methods generally utilized in the toolmarks and materials laboratory and the photography laboratory of the Israel Police, most of the indented impressions on the plastic were deciphered and a connection between the plastic envelope and the stolen credit card was demonstrated.  相似文献   
412.
413.
This article provides an analysis of the regulatory framework of Australian private health insurance linked to four major implicit regulatory objectives: promoting access to health insurance for consumers; promoting financial solvency and industry viability of registered health benefits organisations; promoting competition between registered health benefits organisations; and promoting accountability to consumers. Through an analysis of regulatory changes, case law and policy documents on the performance of the health insurance industry, it is argued that existing health insurance regulation exhibits inevitable tensions due to shifting and often conflicting government objectives about the role of private health insurance.  相似文献   
414.
1,4-Dihydropyridines calcium channel antagonists (1,4-DHP CCAs) are photolabile and the products of their photodecomposition have no pharmaceutical activity. In our previous work we have presented a screening procedure for eleven 1,4-DHPs in plasma by LC-MS-MS using multiple reaction motoring. The laboratory process includes preparation and storage of stock solutions, plasma storage, solid-phase extraction, reconstitution of extracts and storage time in an autosampler for LC-MS-MS analysis. Prior to validation of the analytical procedure, we have tested the stability of these compounds by exposure to light. Methanolic solutions have been exposed to laboratory and UV light and the stability of the compounds in plasma was tested by exposure of spiked plasma samples to laboratory light at room temperature. Stability during freeze-thaw cycles and stability during 2 month storage at -20 degrees C have been tested as well. Products of photodecomposition have been identified after forced degradation and the degree of degradation has been quantified using LC-UV-DAD and LC-MS-MS, respectively. A 96% degradation after only 2h has been observed when solutions of nifedipine or nisoldipine were exposed to laboratory light in clear glass vials. In plasma samples degradation was 25% in only 2h for both compounds. The main degradation product was produced by oxidation of the dihydropyridinic ring resulting in the pyridine analogue that has been described as the first metabolite in the metabolic pathway. Only minor degradation was found for the other tested compounds after 2h light exposure in methanolic solutions. Furthermore, lercanidipine and nicardipine were also degradated by esterhydrolysis. Several additional minor degradation products were found for the other tested 1,4-DHPs, however, some of them could not be identified. Preconditions for storage and handling of plasma samples prior to and during analysis for 1,4-DHP CCAs are suggested in order to avoid photodecomposition of the analytes.  相似文献   
415.
During the past 20 years, researchers have documented the widespread problem of rape in American society. Approximately one in four women are raped in their adult lifetime, which causes severe psychological distress and long-term physical health problems. The impact of sexual assault extends far beyond rape survivors as their family, friends, and significant others are also negatively affected. Moreover, those who help rape victims, such as rape victim advocates, therapists, as well as sexual assault researchers, can experience vicarious trauma. Future research and advocacy should focus on improving the community response to rape and the prevention of sexual assault.  相似文献   
416.
The Brazilian polymer industry (plastics, rubbers, fibers, adhesives, paints, and varnishes) is the fastest growing segment of the Petrochemical Chain. Since the polymer industry is characterized as science based, the capacity to create technology is vital for its long-range survival in the market. This paper analyzes how Brazilian polymer firms maintain their technological competitiveness, explains the main modes of technology transfer, and evaluates the degree of technological dependence of this industry. The methodology consisted of a database built with data from the Brazilian Patent Office. To confirm the findings, interviews were conducted with staff members from seven Brazilian polymer firms. The data base analysis and the interviews reveal that, in spite of the fact that Research and Development (R&D) and technological innovation have a fundamental role in their competitiveness, the firms are technologically dependent upon foreign suppliers.  相似文献   
417.
418.
419.
Medical examiners and coroners (ME/C) in the United States hold statutory responsibility to identify deceased individuals who fall under their jurisdiction. The computer‐assisted decedent identification (CADI) project was designed to modify software used in diagnosis and treatment of spinal injuries into a mathematically validated tool for ME/C identification of fleshed decedents. CADI software analyzes the shapes of targeted vertebral bodies imaged in an array of standard radiographs and quantifies the likelihood that any two of the radiographs contain matching vertebral bodies. Six validation tests measured the repeatability, reliability, and sensitivity of the method, and the effects of age, sex, and number of radiographs in array composition. CADI returned a 92–100% success rate in identifying the true matching pair of vertebrae within arrays of five to 30 radiographs. Further development of CADI is expected to produce a novel identification method for use in ME/C offices that is reliable, timely, and cost‐effective.  相似文献   
420.
A fundamental dilemma which troubles advocates of interinstitutional partnerships in regional development pertains to the extent to which partnerships enhance the effectiveness of governance processes and outcomes. This dilemma is particularly relevant in contexts that lack strong cohesive regional development alliances, such as the Portuguese case. This article aims to shed light on the debate regarding the role of partnerships in regional development, drawing on a unique collaborative interinstitutional partnership. It explores the responses to complexity across the different stakeholders, as well as its effects at the formulation and implementation stages of the strategic plans devised to apply for EU funding. Findings suggest that interinstitutional partnerships induce significantly different allocative choices at the agenda-setting. However, the established partnership was unable to cope with the several obstacles that emerged during the implementation, suggesting several vulnerabilities of partnerships, which are explored. Findings suggest the need to reinforce governance mechanisms during the implementation stage.  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