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   7425篇
  免费   237篇
各国政治   323篇
工人农民   307篇
世界政治   538篇
外交国际关系   359篇
法律   4316篇
中国政治   62篇
政治理论   1684篇
综合类   73篇
  2023年   56篇
  2021年   53篇
  2020年   90篇
  2019年   144篇
  2018年   186篇
  2017年   186篇
  2016年   203篇
  2015年   141篇
  2014年   194篇
  2013年   798篇
  2012年   215篇
  2011年   211篇
  2010年   168篇
  2009年   202篇
  2008年   201篇
  2007年   219篇
  2006年   211篇
  2005年   159篇
  2004年   189篇
  2003年   192篇
  2002年   162篇
  2001年   261篇
  2000年   258篇
  1999年   196篇
  1998年   100篇
  1997年   95篇
  1996年   91篇
  1995年   89篇
  1994年   100篇
  1993年   93篇
  1992年   153篇
  1991年   137篇
  1990年   152篇
  1989年   157篇
  1988年   157篇
  1987年   156篇
  1986年   123篇
  1985年   139篇
  1984年   115篇
  1983年   103篇
  1982年   84篇
  1981年   76篇
  1980年   64篇
  1979年   64篇
  1978年   51篇
  1977年   35篇
  1976年   39篇
  1975年   44篇
  1974年   51篇
  1973年   44篇
排序方式: 共有7662条查询结果,搜索用时 15 毫秒
911.
Isotachophoresis, a technique to separate components by constant current electrophoresis, was used to differentiate between bloodstains of male, female, menstrual, bovine, and ovine bloods on cotton cloth and filter paper. Bloodstain analysis by isotachophoresis of stains from male and female subjects showed identical cationic patterns, but gave different profiles in the anionic system. Plasma had one extra peak in the anionic system when compared to the profile of serum. This extra peak is due to the presence of fibrinogen in plasma. Some hemoglobin peaks overlapped with serum protein peaks, but these could be identified by comparisons at lower concentrations. Menstrual blood had a much different pattern than normal human blood as was expected since many more compounds are found in menstrual blood than in normally circulating blood. Human, bovine, and ovine bloodstains showed different profiles both in the cationic and anionic systems. These results indicate that isotachophoresis can be used for the rapid and simple analysis of bloodstains to differentiate reliably human male, female, and menstrual blood and also to distinguish human bloodstains from those of cattle or sheep.  相似文献   
912.
A method was developed for the specific determination of digoxin and digitoxin, as well as their semisynthetic derivatives and dependent cardioactive metabolites, in autopsy samples of heart and kidney. A collective of six patients on long-term treatment with therapeutic doses of beta-acetyldigoxin had a mean myocardial digoxin content of 46.1 +/- 25.0 ng/g (SD); kidney: 50.3 +/- 30.3 ng/g. Digoxigenin bisdigitoxoside represented the second most important metabolite in heart and kidney; digoxigenin monodigitoxoside and digoxigenin follow, respectively. In a collective of seven patients on maintenance treatment with digitoxin, the mean tissue levels were higher but the metabolic pattern was similar (myocardial digitoxin content: 78.9 +/- 38.4 ng/g, renal content: 104.1 +/- 44.1 ng/g). The amount of digoxin formed by hydroxylation under long-term treatment with digitoxin in heart and kidney were approximately 10 ng/g. A case of digoxin intoxication differed both in the tissue content and in the metabolic distribution.  相似文献   
913.
The intake of 0.51 of water glass (sodium metasilicate; colloid pH 12.5) led to death within 1-1.5 h. Autopsy revealed alkali burns of the stomach mucosa. The stomach contained a small amount of liquid with a pH of 11.5. Histologically, numerous bronchioles and alveoles were filled with amorphous material. This material was chemically proved to be condensed water glass. The obstruction of large parts of the lungs by water glass led to an inhibition of alveolar gas diffusion, which may have been the cause of death. The transformation of the water glass from liquid to solid occurred in the lungs by means of the carbonic acid of expiration air. This was made possible because the pH of water glass had been changed by gastric secretions from 12.5 to 11.5. Water glass starts to solidify around pH 11.4-11.3.  相似文献   
914.
Review     
  相似文献   
915.
916.
917.
A mail survey of California district attorneys regarding corporate crime focused on the recent experiences of the prosecutors with such crimes and on factors that limit the likelihood of their prosecuting corporate offenders. A significant majority of the district attorneys had prosecuted a variety of corporate crimes, and a sizable minority anticipated devoting more resources to corporate crime prosecutions in the future. There was a strong consensus among the district attorneys that the primary obstacle to corporate crime prosecutions is not political but practical and inheres in the level of resources available to them. Prosecutors in small districts were more constrained by the potential impact that a corporate prosecution might have on the local economy than their counterparts in large districts. This finding suggests that community context may influence social control responses to corporate lawbreakers.  相似文献   
918.
A simple isoelectric focusing method for haptoglobin (HP) typing is described. Serum was pretreated first with C. perfringens neuraminidase (CPN) and then with dithiothreitol (DTT). The treated serum was subjected to polyacrylamide gel isoelectric focusing (PAGIF), and the band patterns were detected by immunoblotting. The method could be successfully applied to HP typing of bloodstains as old as 2 months. A slight modification of it enabled HP, complement component C81, and factor I (IF) to be typed simultaneously. The immunoblotting facilitated preservation of HP patterns. Thus, the PAGIF method for HP typing is suitable for routine use in the forensic laboratory.  相似文献   
919.
The present report describes the component of our treatment program that is aimed at enhancing intimacy skills and reducing loneliness in sexual offenders. The evaluation of this component, although limited in sophistication, offers data that encourages confidence in the value of the treatment component.  相似文献   
920.
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