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   11340篇
  免费   350篇
各国政治   762篇
工人农民   421篇
世界政治   914篇
外交国际关系   524篇
法律   6163篇
中国共产党   2篇
中国政治   157篇
政治理论   2639篇
综合类   108篇
  2020年   148篇
  2019年   173篇
  2018年   252篇
  2017年   273篇
  2016年   294篇
  2015年   242篇
  2014年   245篇
  2013年   1454篇
  2012年   273篇
  2011年   367篇
  2010年   275篇
  2009年   295篇
  2008年   308篇
  2007年   282篇
  2006年   292篇
  2005年   262篇
  2004年   298篇
  2003年   306篇
  2002年   229篇
  2001年   403篇
  2000年   368篇
  1999年   326篇
  1998年   196篇
  1997年   140篇
  1996年   143篇
  1995年   151篇
  1994年   146篇
  1993年   139篇
  1992年   189篇
  1991年   191篇
  1990年   184篇
  1989年   176篇
  1988年   195篇
  1987年   193篇
  1986年   197篇
  1985年   179篇
  1984年   174篇
  1983年   183篇
  1982年   125篇
  1981年   87篇
  1980年   101篇
  1979年   108篇
  1978年   103篇
  1977年   87篇
  1976年   85篇
  1975年   72篇
  1974年   73篇
  1973年   64篇
  1972年   63篇
  1969年   67篇
排序方式: 共有10000条查询结果,搜索用时 9 毫秒
221.
222.
The end of the twentieth century was marked by a sea change in global governance in the realm of intellectual property rights (IPRs). Whereas countries historically retained substantial autonomy with regard to what they defined as intellectual "property" and the rights granted to the owners of intellectual property, the 1990s witnessed the establishment of new global obligations regarding national practices. This paper focuses on the case of software "piracy" to assess the mechanisms by which the new global obligations for the treatment of IPRs are transmitted from the international to the national levels. We first consider a set of national-level factors that many scholars have shown to be important determinants of IPR policy. We then supplement the standard emphasis on domestic factors with an analysis of new transnational factors: countries' multilateral obligations under the World Trade Organization's (WTO) Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPS) and bilateral pressures from the United States to increase the protection of IPRs. Population-averaged panel data models are used to assess the effects of these national and transnational determinants on levels of software piracy in 80 countries from 1994 to 2002. Our results indicate that membership in the WTO and bilateral pressures from the United States—particularly pressures that offer reciprocal concessions—lead to substantial increases in levels of protection in rich and poor countries. There is, in short, a new international political economy of intellectual property.  相似文献   
223.
224.
225.
226.
Papillary hyperplasia of the lingual tonsils is a rare entity not previously reported at autopsy. We report a case that occurred in a 19-year-old man who died suddenly from his epilepsy, associated with aspiration of gastric contents. We describe the pathological features of this unusual condition, discuss the possible significance in this case and stress the importance of routine examination of the tongue and pharynx in every autopsy.  相似文献   
227.
A 22-year-old Korean soldier, who had received blows to the neck and epigastrium from an officer 10 h earlier, suddenly died after massive hematemesis. He had been in relatively good health except for episodes of blood-tinged vomiting approximately 5 and 7 months prior to this event. Postmortem examination revealed angiodysplasia involving the gastroesophageal junction, and the stomach was distended with blood. No abnormal findings were present around the whole viscera, and the duodenum was free of blood. The pathologic significance of upper gastrointestinal angiodysplasia as a potential source of bleeding and a chronologic correlation between the trauma and bleeding are discussed.  相似文献   
228.
A gas chromatographic (GC) fingerprint method, based on the presence or absence of six congeners, was developed for illicit cocaine samples. The fingerprint utilizes the relative abundances of these congeners towards each other, disregarding cocaine as the main constituent, and can be expressed numerically or graphically in the form of pictograms for rapid visual comparison. The method can be applied directly to a solution of the sample in chloroform, without previous workup procedures. More than 70 unrelated samples were analyzed and a great variation was observed in the parameter composition. On the other hand, a remarkable similarity could be seen between related samples. The GC fingerprint method may be considered an important contribution for sample comparison, as is exemplified by a subdivision of the analyzed samples in different categories, based on the number and types of congeners found.  相似文献   
229.
Neural networks were developed to study and mimic the functioning of the human brain. Humans are good at pattern recognition; the question is how good neural networks are at it, particularly with problems of forensic science interest. Simulation experiments with a type of neural network known as a Hopfield net indicate that it may have value for the storage of toolmark patterns (including bullet striation patterns) and for the subsequent retrieval of the matching pattern using another mark by the same tool for input. Another type of neural network, the back-propagation network (BPN), is useful for applications similar to those for which standard statistical methods of pattern classification can be used. This would be an appropriate approach to the matching of general component patterns, such as gas chromatograms of gasoline, or pyrolysis patterns from materials of forensic science interest, such as paint. The BPN may provide better results than statistical methods, but it is currently necessary to try both to determine which would be best for any given situation.  相似文献   
230.
On the one hand the following case demonstrates the problems of finding a dead body in the bathroom and on the other hand the importance of postmortem x-ray examinations. The corpse of an 65-year-old woman was discovered in her bath tub. At the body's feet there was a hair dryer. Investigations concerning murder were negative, circumstances appeared to be unsuspicious. That was why a postmortem examination was not performed. -4 years later murder had to be considered. After manual strangling the deceased and the hair dryer were layed into the bath tub. The corpse was exhumed and taken to a forensic autopsy. It was found that the hyoid bone and the superior horn of the thyroid cartilage were both fractured on the right. Damages caused by the preparation itself were excluded by using serial roentgenographs. These observations in combination with histological findings and the results of further investigations convincingly supported the suspicion of strangling by hand.  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