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   341篇
  免费   17篇
各国政治   40篇
工人农民   24篇
世界政治   28篇
外交国际关系   36篇
法律   147篇
中国共产党   1篇
中国政治   16篇
政治理论   59篇
综合类   7篇
  2022年   2篇
  2021年   5篇
  2020年   11篇
  2019年   12篇
  2018年   14篇
  2017年   19篇
  2016年   11篇
  2015年   12篇
  2014年   15篇
  2013年   63篇
  2012年   18篇
  2011年   9篇
  2010年   14篇
  2009年   15篇
  2008年   14篇
  2007年   12篇
  2006年   7篇
  2005年   10篇
  2004年   14篇
  2003年   8篇
  2002年   12篇
  2001年   5篇
  2000年   6篇
  1999年   4篇
  1998年   6篇
  1997年   3篇
  1996年   2篇
  1995年   4篇
  1993年   5篇
  1992年   2篇
  1991年   3篇
  1990年   3篇
  1988年   2篇
  1987年   1篇
  1986年   2篇
  1984年   3篇
  1982年   1篇
  1981年   3篇
  1978年   1篇
  1974年   1篇
  1973年   1篇
  1970年   1篇
  1967年   2篇
排序方式: 共有358条查询结果,搜索用时 15 毫秒
131.
Recent research has expanded our understanding of sexual homicide offenders (SHOs). However, little exists beyond case reports for older SHOs. We characterized male SHOs ≥ 55 years, comparing them to typical adult male SHOs who are in their 20s. Analysis of 37 years (1976–2012) of US Supplementary Homicide Reports data provided a large SHO sample (N = 3453). Three case reports provide clinical context for the diverse nature and patterns of older SHOs. Only 32 older male SHOs and no older female SHOs were identified. Murders by older SHOs accounted for only 0.5% of US sexual homicides. Unlike typical SHOs that generally target young adult females, over two‐thirds of older SHO victims were ≥40 years, and one‐third were ≥55 years. Sexual homicides by older SHOs, like sexual homicide in general, decreased over the study period. These crimes, while exceedingly rare, do occur, warranting special consideration.  相似文献   
132.
This paper examines the role of China in the G20 and in East Asia in crafting appropriate responses and policies to the global financial crisis. Did China play an important part in the multilateralisation of the Chiang Mai Initiative, and how did China work with other players in East Asia to ‘inoculate’ East Asia against contagion and fallout from the crisis? The paper evaluates the type of leadership displayed by China and the decisions taken during the crisis. It assesses how the Chinese role in its own region and within global institutions such as the G20 would change in the aftermath of these crises.  相似文献   
133.
将通过PCR技术扩增的牛型布鲁氏菌铁离子转运蛋白(Brucellaferric uptake,BfuA)基因克隆至表达载体pCold TF中,构建重组表达质粒pCold TF-BfuA,转化大肠杆菌BL21(DE3)后,在IPTG诱导下表达出大小约为100ku的融合蛋白His-BfuA。Western-blot分析表明,His-BfuA能与布鲁氏菌阳性牛血清发生特异性反应,表明BfuA具有免疫原性。用His-BfuA作为包被抗原,对35份布鲁氏菌阳性牛血清进行ELISA检测,结果所有被检血清均为阳性反应,表明BfuA为潜在的可用于牛型布鲁氏菌诊断的靶蛋白。此外,对BfuA的亚定位结果表明,BfuA为膜蛋白;对His-BfuA的纤连蛋白结合活性及纤连蛋白溶酶原结合活性的试验结果表明,His-BfuA不具有上述2种活性。上述结果为牛型布鲁氏菌病诊断方法的建立及亚单位疫苗的研制奠定了基础。  相似文献   
134.
This paper reports a new capillary zone electrophoresis method for the simultaneous chiral determination of the enantiomers of N,N-dimethylamphetamine (DMA), methamphetamine (MA), ephedrine (E), pseudoephedrine (PE) and methylephedrine (Me-E). In this study, a number of electophoretic parameters were examined and optimized including the choice of chiral selectors, the use of short-chain tetraalkylammonium cations, the effect of chiral selector concentration, buffer concentration, applied voltage and capillary temperature. Heptakis(2,6-di-O-methyl)-beta-cyclodextrin (DM-beta-CD) and tetrabutylammonium (TBA) being the best chiral selector and buffer cation, respectively, the optimized electrophoretic conditions were found to be: 20 mM DM-beta-CD, 50 mM TBAPO(4) at pH 2.5, applied voltage at 30 kV and temperature at 25 degrees C. Under the optimized conditions, all analytes were well separated with resolution factors between 3.3 and 24.0 achieved. Using phentermine as an internal standard, the intra-day (n=8) precisions for the relative migration times and peak areas of all analytes were below 1.09%, while the inter-day precisions (n=12, 6 days) for the relative migration times and peak areas of all analytes were under 3.77%. This method has been applied to the measurement of the enantiomeric purities of the seized DMA samples. The result of the measurement could provide important clues about the possible synthetic pathways of these samples.  相似文献   
135.
Abstract: An investigation is presented of the explosion of a CNG (compressed natural gas) fuel vessel, called a liner, in an urban bus. The explosion happened at a gas station 10 min after filling was completed. There were no traces of soot and flames at the failed liner, which would be indicative of explosion by ignition of the gas. The filling process of the station was automatically monitored and recorded in a computer. There was no unusual record of the filling system that indicated excess pressure at the time of the accident. There were cracks on the liner that were initiated at the outer surface of the cylindrical shell located at a point 4 cm above the lower dome where cracks did not originate easily as a result of overload. Chemical analysis was performed on a specimen that was cut from the liner, and there was no peculiarity in the mix. Mechanical analysis was performed on the specimens and showed that the hardness was not in the specified range because of inadequate heat treatment of the metal. The hardness of the liner was strictly controlled in the manufacturing process. All the liners that were manufactured at the same period with the failed liner were recalled for examination.  相似文献   
136.
137.
In the case of building collapses and overturned structures, a three‐dimensional (3D) collapse or overturn model is required to reconstruct the accident. As construction sites become increasingly complex and large, 3D laser scanning is sometimes the best tool to accurately document and store the site conditions. This case report presents one case of a structure collapse and one case of an overturned crane reconstructed by a 3D laser scanner. In the case of structural collapse of a prefabricated shoring system, a 3D model reconstructed all the members successfully, a task that is nearly impossible using a scale such as a tape measure. The reconstructed prefabricated shoring system was verified through a structural analysis through comparison with the construction drawings to investigate faults in construction. In the case of the overturned crane, the jib angle and other major dimensions were successfully acquired through 3D laser scanning and used to estimate the working radius. As a result, the propriety of the working radius with the given lifting load was successfully determined.  相似文献   
138.
2009年2月25日,美籍华人骆家辉(Gary Faye Locke)被奥巴马任命为商务部部长,成为新一届政府14位内阁部长中的第二位华裔部长。尽管此前奥巴马提名商务部长两度受挫,但选择前华盛顿州州长骆家辉仍为奥巴马赢得不少分数。白手起家、靠实干获取信任的骆家辉不仅符合新总统的执政理念与风格,更符合美国面临的国内外新环境。骆家辉的成功代表着华裔参政的成功,能赢得这份殊荣不仅是他个人努力的结果,更与美国社会包容、中国崛起等因素息息相关。  相似文献   
139.
Conventional wisdom argues that a good set of performance measures builds accountability and that improved accountability generates better productivity in the organisation. By way of an analysis of a case study in one inland Chinese county, this article shows that the assumed relationship between performance and accountability is more rhetoric than real. In practice, the implementation of performance measurement in local China leads to an accountability paradox, in which enhanced accountability tends to hinder the improvement of government productivity. The implementation of the Chinese target-based responsibility system risks boosting the short term accountability of public employees while undermining the long term productivity of government agencies. With the deepening of China's market-oriented reform, this choice appears to put the cart before the horse.  相似文献   
140.
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