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   168篇
  免费   8篇
各国政治   1篇
工人农民   3篇
世界政治   1篇
外交国际关系   35篇
法律   65篇
中国政治   3篇
政治理论   48篇
综合类   20篇
  2023年   1篇
  2022年   2篇
  2021年   2篇
  2020年   15篇
  2019年   10篇
  2018年   15篇
  2017年   7篇
  2016年   6篇
  2014年   10篇
  2013年   5篇
  2012年   10篇
  2011年   7篇
  2010年   8篇
  2009年   6篇
  2008年   9篇
  2007年   4篇
  2006年   8篇
  2005年   10篇
  2004年   5篇
  2003年   6篇
  2002年   7篇
  2001年   6篇
  2000年   14篇
  1997年   1篇
  1995年   1篇
  1984年   1篇
排序方式: 共有176条查询结果,搜索用时 31 毫秒
11.
Privatisation, coupled with liberalisation and competition, constitutes one of the most popular policy options to improve the performance of state-owned enterprises. However, in Greece, it was only after 1991 that privatisation started to gain ground in the political and economic agendas of governments. Drawing upon the theoretical underpinnings of privatisation, the paper overviews and critically analyses the new legal framework on denationalisation in Greece. The paper argues that, though the modernisation of the legal regime is welcomed, the Greek government has failed to treat privatisation as part of wider structural reforms aiming at enhancing competition and foreign investment. The paper concludes that wider structural reforms, including regulatory reform and liberalisation, as well as combating corruption and bureaucracy and promoting transparent capital markets, are absolutely necessary in order to create a competitive environment, which would both complement and support privatisation efforts.  相似文献   
12.
利用RT-PCR扩增了2株H5N1亚型禽流感病毒NS1基因,并将其克隆到pMD 18-T载体上,进行序列分析。结果显示,这2株禽流感病毒NS1基因核苷酸序列的同源性为70.2%,分别属于NS等位基因群A和等位基因群B。再将克隆的NS1基因插入到pET-28a质粒中构建原核表达载体,将其转化到DH5α大肠埃希氏菌感受态细胞中,经双酶切鉴定及序列分析,表明获得了重组质粒pET-52NS1和pET-174NS1。经SDS-PAGE分析,重组质粒转化BL21(DE3)(pLysS)感受态细胞后,经IPTG诱导,获得了分子质量约为30 ku的NS1融合蛋白。用AIV多克隆血清做Western-blotting分析,发现来自2个等位基因群的NS1蛋白都具有较好的抗原活性。  相似文献   
13.
阅读是一项交际活动.阅读教学中运用语篇分析方法将语言单位放在语篇水平上来理解,对培养学生的阅读理解能力,发展语言交际能力,提高阅读水平有着促进作用.  相似文献   
14.
采用SDS 蛋白酶K法抽提鸡传染性支气管炎病毒(IBV)四川分离株SAIBWJ的基因组RNA,参照基因库中的N基因序列设计了1对引物,扩增出了单一的DNA产物。将该产物插入pUC18载体的HindⅢ和BamHⅠ酶切位点,构建了pUC NWJ质粒。序列测定结果表明,获得的克隆质粒包含了全部N基因。再将N基因亚克隆到pcDNA3.1( )载体的HindⅢ和XhoⅠ酶切位点,构建了IBVSAIBWJN基因的DNA免疫质粒pcDNA NWJ。  相似文献   
15.
Self‐driving cars (also known as driverless cars, autonomous vehicles, and highly automated vehicles [HAVs]) will change the regulatory, political, and ethical frameworks surrounding motor vehicles. At the highest levels of automation, HAVs are operated by independent machine agents, making decisions without the direct intervention of humans. The current transportation system assumes human intervention though, including legal and moral responsibilities of human operators. Has the development of these artificial intelligence (AI) and autonomous system (AS) technologies outpaced the ethical and political conversations? This paper examines discussions of HAVs, driver responsibility, and technology failure to highlight the differences between how the policy‐making institutions in the United States (Congress and the Public Administration) and technology and transportation experts are or are not speaking about responsibility in the context of autonomous systems technologies. We report findings from a big data analysis of corpus‐level documents to find that enthusiasm for HAVs has outpaced other discussions of the technology.  相似文献   
16.
Since its inception in 2009, Uber has grown into a technology behemoth, with operations in over 70 countries and 500 cities around the world. Along the way, it has successfully forced regulatory upheaval in hundreds of local taxi markets controlled by municipal authorities. In this sense, Uber is not only a market disruptor, but also a policy disruptor. This paper examines the nature of such policy disruption at the local level by reviewing regulatory responses to Uber in ten North American cities. We find that regulatory outcomes are a function of two factors: Uber’s government relations strategy, either cooperative or confrontational, and the degree to which local governments perceive Uber as complementary or harmful to the existing marketplace. We conclude by proposing a typology of regulatory responses to Uber as a basis to identify patterns in the behavior of municipal regulatory authorities and political leaders.  相似文献   
17.
为进一步分析H7N2禽流感病毒(AIV)分离株血凝素(HA)基因的特性,参照已发表序列设计了1对引物,采用RT-PCR获得了1条约1.7 kb的DNA片段,测序后进行了同源性比较、HA基因系统发育进化树分析和氨基酸编码分析。结果表明,所测的2个分离株的HA基因全长1 664 bp,编码除信号肽以外的HA蛋白的全部544个氨基酸,其中包括HA1的323个氨基酸,HA2的221个氨基酸。2个分离株HA基因核苷酸序列的同源性为99.4%;与GenBank中AIV标准株A/Afri.Star./Eng-Q/983/79(H7N1)的同源性最高,分别为99.4%和99.0%;与美国A/Chicken/NewYork/13142-5/94(H7N2)株同源性很低(仅65.0%),而与以色列、意大利H7N2AIV的同源性较高(为96%~97%);2个分离株在HA基因进化树中均处于H7亚型AIV的欧亚群系分支内。推导氨基酸的序列分析表明,其HA蛋白裂解位点的氨基酸序列为-GR-GLF-,仅包含1个碱性氨基酸(R-)残基,符合低致病力AIV的基因特征。  相似文献   
18.
采用RT-PCR方法对1株H9N2亚型禽流感病毒Ck/GS/2/99株RNA聚合酶基因PB2、PB1和PA分别进行了扩增,将其克隆到pGEM-T easy载体后进行序列测定与分析。结果表明,该株病毒的PB2、PB1和PA基因开放阅读框(ORF)分别由2280、2274和2 151个碱基组成,分别编码759、757和716个氨基酸。经同源性与系统发生树分析,该毒株RNA聚合酶基因PB2、PB1和PA与Ck/NX/4/99株的核苷酸和氨基酸同源性均在98%以上,另外这3个基因与Dk/HK/Y280/97、Sw/HK/9/98和Qu/HK/NT/28/99株的关系密切。  相似文献   
19.
Acid scavengers are frequently used as stabilizer compounds in a variety of applications. When used to stabilize volatile compounds such as nerve agents, the lower volatility and higher stability of acid scavengers make them more persistent in a post-event forensic setting. Compound-specific isotope analysis of carbon, nitrogen, and hydrogen in three acid-scavenging compounds (N,N-diethylaniline, tributylamine, and triethylamine) were used as a tool for distinguishing between different samples. Combined analysis of multiple isotopes improved sample resolution, for instance differentiation between triethylamine samples improved from 80% based on carbon alone to 96% when combining with additional isotope data. The compound-specific methods developed here can be applied to instances where these compounds are not pure, such as when mixed with an agent or when found as a residue. Effective sample matching can be crucial for linking compounds at multiple event sites or linking a supply inventory to an event.  相似文献   
20.
Abstract: The question of whether the insect repellent N,N‐Diethyl‐meta‐toluamide (DEET) affected fly attraction, oviposition, and larval development was investigated; in part, to determine whether the common habit of wearing DEET as a repellent could affect the rate of human decomposition. Experiments using pig surrogates of human decedents were carried out in a rural environment. Dead piglets were sprayed with DEET, and fly behavior, colonization levels, and maggot development were compared with those in nonsprayed controls. Piglets treated with DEET experienced significant delays in fly visitation and oviposition and delayed appearance of each larval instar, as well as reduced total larval numbers (p < 0.01 for all variables), with subsequently reduced decomposition (p < 0.05). Such changes in fly behavior and larval population development would significantly impact the estimation of the period following the death from entomological evidence in decedents wearing DEET at the time of their death.  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