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   394篇
  免费   12篇
各国政治   23篇
工人农民   9篇
世界政治   28篇
外交国际关系   29篇
法律   210篇
中国政治   1篇
政治理论   104篇
综合类   2篇
  2023年   3篇
  2022年   1篇
  2021年   2篇
  2020年   5篇
  2019年   7篇
  2018年   20篇
  2017年   14篇
  2016年   12篇
  2015年   10篇
  2014年   14篇
  2013年   53篇
  2012年   16篇
  2011年   15篇
  2010年   16篇
  2009年   16篇
  2008年   18篇
  2007年   15篇
  2006年   16篇
  2005年   17篇
  2004年   17篇
  2003年   17篇
  2002年   9篇
  2001年   8篇
  2000年   18篇
  1999年   4篇
  1998年   4篇
  1997年   5篇
  1996年   8篇
  1995年   3篇
  1994年   3篇
  1993年   4篇
  1992年   2篇
  1991年   2篇
  1990年   4篇
  1989年   4篇
  1987年   2篇
  1986年   1篇
  1985年   3篇
  1984年   3篇
  1981年   2篇
  1980年   3篇
  1979年   3篇
  1977年   1篇
  1974年   2篇
  1973年   1篇
  1970年   2篇
  1963年   1篇
排序方式: 共有406条查询结果,搜索用时 15 毫秒
281.
When analysing trace materials and degraded DNA the issue of human specificity is highly important. Especially when it comes down to the analysis of mitochondrial DNA which is extremely susceptible to contamination authenticity is the main question. Therefore in the presented study mitochondrial primers were tested on their human specificity. In all cases it was possible to amplify DNA of animals with human mt-primers. These unintentional amplifications could only be decreased by choosing austere PCR parameters. The study implies the importance of comprehensive evaluation of primers, chemicals and PCR parameters.  相似文献   
282.
283.
A 36-year-old woman consulted the medical emergency unit of a private health center for abdominal pain and gastroenteritis of 5 days duration. Acute right pyelonephritis was diagnosed. Five hours after admission she became unconscious in a state of clinical shock. She was transferred to an intensive care unit but resuscitation attempts were unsuccessful and she died 3 h later. Three days after death, she was buried in the family vault. Five days after the burial, her husband lodged a complaint with the public prosecutor because he had not received a clear explanation from the physicians concerning the cause of his wife's death. After analysis of the medical records of the deceased by two forensic pathologists, a medicolegal autopsy was ordered by the public prosecutor. The corpse was exhumed and autopsy performed 9 days after death. Massive hemoperitoneum was diagnosed with a macroscopically ruptured subcapsular hematoma. Pathological study confirmed acute right pyelonephritis and demonstrated the precise cause of the hemorrhage: rupture of the hepatic artery at the hilar part, following infectious arteritis which was probably secondary to the acute pyelonephritis. To the best of our knowledge, this is the first published report of such a case.  相似文献   
284.
285.
Lifetime prevalence of opioid dependence is about 0.4% in western countries. Opioid‐dependent patients have high morbidity and mortality and a high risk of criminal behavior. Few studies have addressed the long‐term impact of opioid maintenance therapy on convictions and criminal behavior. The PREMOS study is a prospective, longitudinal, naturalistic clinical study of a nationally representative sample of 2694 opioid‐dependent patients to investigate convictions and criminal behavior at baseline and after 6 years of maintenance treatment. At follow‐up, 2284 patients still were eligible (84.7%). A comprehensive assessment including a patient and doctor questionnaire, and the EuropASI was completed at baseline and follow‐up. Data on criminality at follow‐up had been received for 1147 (70.6%) patients. A large number (84.5%) of them had been charged or convicted at any time before baseline assessment, most frequently with drug‐related offenses (66.8%), acquisitive crime (49.1%), or acts of violence (22.0%). Reported charges and convictions had declined to 17.9% for the last 12 months before follow‐up, which was also reflected by a significant decrease in the EuropASI subscore “legal problems” from 1.52 at baseline to 0.98 after 6 years. These data indicate a significant and clinically relevant reduction in criminal behavior in opioid‐dependent patients in long‐term maintenance treatment. Maintenance therapy is effective in the reduction in both narcotics‐related and acquisition crime.  相似文献   
286.
This study presents and discusses the mass spectrometric, nuclear magnetic resonance spectroscopic and infrared spectroscopic data of the designer drugs pentedrone (2-methylamino-1-phenylpentan-1-one) and its methylenedioxy analog pentylone (2-methylamino-1-(3,4-methylenedioxyphenyl)pentan-1-one). The structure elucidation of the aliphatic parts was carried out by product ion spectroscopy of the immonium ion with m/z=86 formed after electron ionization, and by one- and two-dimensional (1)H- and (13)C-NMR spectroscopy on the hydrochloride salts to verify the structure of the alkyl side chain and to determine the methylenedioxy position in the aromatic ring of pentylone. Furthermore, two typical cathinone synthesis by-products were detected besides the main compounds. Their mass spectra are discussed and for one of them (1-methylamino-1-phenylpentan-2-one (isopentedrone)) a NMR assignment was possible in the existing mixture.  相似文献   
287.
The HSP70 superfamily is a reliable biomarker for hyperthermia, hypothermia and hypoxia. The Enzyme-linked Immunosorbent Assay (ELISA) respectively immunohistochemically staining methods are the typically used techniques for the quantification of those proteins. As the costs for reagents and devices as well as the work schedule of these methods are immense it was the goal of our study to develop an easy and reliable method to quantify the concentration of specific proteins. We established a procedure to measure the relative concentration of proteins fixed on ROTI(?) PVDF membranes via Western blot, calculating the relative protein concentration in dependency to the grey scale index of the normalized and digitalized pictures of the bands on the blots.  相似文献   
288.
In order to study the conditions for the formation of so-called rustmarks on the skin after contact with weapon steel tests to provoke rustmarks were performed on corpses and living bodies. These tests were only successful under the condition of a firm contact with the weapon steel and a certain minimum contact time between the weapon and the skin. The experiments showed that the critical parameters for the appearance of rustmarks are, first, the humidity of the skin and the environment, respectively, as well as the contact time, and second, the state of the weapon surface (greased or ungreased). Both the ambient temperature and the pH value of the skin (alkaline or acid) are irrelevant to the formation of rust. The longest time period until rustmarks appeared was observed on dry skin in contact with a greased weapon, namely 22 hours on a corpse and 170 min on a living subject. When using a greased gun humidity accelerated the formation of rust. An ungreased surface of the weapon also resulted in faster rust formation. The minimum time necessary for the formation of rust determined under the most favourable circumstances was 135 min for a corpse and 27 min for a living person. During the early postmortal interval the rustmark may therefore be another piece in the jigsaw towards determining the time of death on suicides committed with firearms.  相似文献   
289.
290.
An impressively large number of clandestinely produced controlled-substance analogues (designer drugs) of amphetamine with high structural variety have been encountered in forensic samples in recent years. The continuous designer drug exploration and their widespread consumption results in an increasing number of reports regarding abuse and intoxication. This study presents the analytical properties of a series of new fluoro-methoxy-substituted controlled-substance analogues of amphetamine. Three ring positional isomeric fluoroamphetamines, two isomeric fluoromethoxyamphetamines, two N-alkyl 4-fluoroamphetamines, and one 4-fluorophenylbutan-2-amine were identified and differentiated by gas chromatography-mass spectrometry (GC-MS), 1H- and 13C-nuclear magnetic resonance (NMR), and gas chromatography-infrared spectroscopy (GC-IR). The regioisomeric 2-, 3-, and 4-fluoroamphetamines and the regioisomeric fluoro-methoxyamphetamines show virtually identical mass spectra so that this method is insufficient to discriminate between these closely related compounds. The mass spectra of the acetylated compounds allowed a differentiation of the 4-fluoroamphetamine from its regioisomeric 2- and 3-fluoroamphetamines. The gas chromatographic properties of the three regioisomeric fluoroamphetamines and their acetylated and trifluoroacetylated derivatives are also so similar that a complete separation of these compounds could not be achieved under GC-MS conditions. The two isomeric compounds 5-fluoro-2-methoxyamphetamine and 3-fluoro-4-methoxyamphetamine on the other hand showed significant different gas chromatographic retention times so that a separation was uncomplicated. The trifluoroacetylation of these compounds proved to be an effective method for their mass spectral differentiation. Gas chromatography-infrared spectroscopy and 1H- and 13C-nuclear magnetic resonance allowed an unequivocal differentiation of all studied regioisomeric fluoroamphetamines and fluoro-methoxyamphetamines.  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