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   1286篇
  免费   81篇
各国政治   6篇
工人农民   3篇
世界政治   9篇
外交国际关系   484篇
法律   670篇
中国共产党   3篇
中国政治   18篇
政治理论   42篇
综合类   132篇
  2024年   7篇
  2023年   11篇
  2022年   13篇
  2021年   22篇
  2020年   38篇
  2019年   27篇
  2018年   21篇
  2017年   19篇
  2016年   28篇
  2015年   20篇
  2014年   30篇
  2013年   34篇
  2012年   74篇
  2011年   82篇
  2010年   74篇
  2009年   113篇
  2008年   158篇
  2007年   196篇
  2006年   104篇
  2005年   88篇
  2004年   53篇
  2003年   44篇
  2002年   27篇
  2001年   19篇
  2000年   18篇
  1999年   13篇
  1998年   5篇
  1997年   5篇
  1996年   2篇
  1995年   2篇
  1994年   2篇
  1993年   6篇
  1992年   3篇
  1991年   2篇
  1989年   4篇
  1986年   1篇
  1985年   1篇
  1981年   1篇
排序方式: 共有1367条查询结果,搜索用时 15 毫秒
151.
Bytewise approximate matching is a relatively new area within digital forensics, but its importance is growing quickly as practitioners are looking for fast methods to screen and analyze the increasing amounts of data in forensic investigations. The essential idea is to complement the use of cryptographic hash functions to detect data objects with bytewise identical representation with the capability to find objects with bytewise similar representations.Unlike cryptographic hash functions, which have been studied and tested for a long time, approximate matching ones are still in their early development stages and evaluation methodology is still evolving. Broadly, prior approaches have used either a human in the loop to manually evaluate the goodness of similarity matches on real world data, or controlled (pseudo-random) data to perform automated evaluation.This work's contribution is to introduce automated approximate matching evaluation on real data by relating approximate matching results to the longest common substring (LCS). Specifically, we introduce a computationally efficient LCS approximation and use it to obtain ground truth on the t5 set. Using the results, we evaluate three existing approximate matching schemes relative to LCS and analyze their performance.  相似文献   
152.
为建立检测非洲猪瘟病毒(African swine fever virus,ASFV)的快速诊断方法,本研究根据ASFV SY18株p17蛋白的编码基因D117L的保守序列设计并合成引物和探针,建立了基于ASFV p17蛋白的编码基因D117L的TaqMan荧光定量PCR检测方法,并验证其特异性、灵敏性和重复性。结果显示,本研究建立的TaqMan荧光定量PCR检测方法的C_t值与标准品在1×10^9~1×10^1copies/μL范围内呈良好的线性关系,相关系数为0.998,斜率为-3.192,检测下限为10 copies/μL,且与其他能引起相似症状的猪源病毒无交叉反应。重复性试验结果显示,组间与组内变异系数均小于1.920 7%,重复性好。此方法可用于ASF的早期诊断和ASFV快速检测。  相似文献   
153.
为了开发一种抗I群4型禽腺病毒(FAd V-4)的亚单位疫苗,选择I群禽腺病毒血清4型流行毒株衣壳蛋白Fiber-2作为保护性抗原蛋白。利用昆虫细胞-杆状病毒系统生产Fiber-2蛋白,通过Westernblot检测重组蛋白的表达情况,利用双向琼脂扩散法检测重组Fiber-2的免疫原性。为了增强亚单位疫苗的免疫保护效果,添加鸡源白细胞介素2(chIL-2)和鸡源γ-干扰素(ch IFN-γ)作为免疫佐剂,与重组Fiber-2单独或混合使用,制备多种形式的亚单位疫苗,并进行动物攻毒保护试验。重组蛋白的Western-blot鉴定结果显示,63 ku处出现Fiber-2蛋白目的条带;双向琼脂扩散试验结果显示,重组蛋白效价达到1∶128,表现出良好的反应原性。动物攻毒保护试验结果显示,单独使用Fiber-2免疫SPF鸡,在50 μg/只的剂量下,可为SPF鸡提供100%的保护效果,以chIL-2和chIFN-γ为免疫佐剂,与重组Fiber-2联合免疫SPF鸡,可显著增强Fiber-2在低剂量(10 μg/只)下的免疫保护效果,上述结果表明重组Fiber-2联合chIL-2和chIFN-γ细胞因子佐剂所制备的亚单位疫苗在抗I群4型禽腺病毒感染领域具有良好的应用前景。  相似文献   
154.
Contemporary research on electoral integrity has focused on the functioning, evaluation, and legitimacy of electoral processes in emerging democracies. By contrast, this study investigates whether a failed election in a well-established democracy can affect individuals' evaluations of the electoral management body, the Election Authority, and whether those evaluations affect satisfaction with democracy. Using the case of a Swedish regional election in 2010 that had to be rerun due to procedural mistakes in the vote handling, we found that, in the short term, individuals’ confidence in the Election Authority was reduced after it was announced that the election had to be rerun because of the mistakes. Subsequently, this decreased confidence was strongly associated with less satisfaction with democracy at the regional and national level. As good news for the authority, after a successful rerun election, confidence rebounded to the levels prior to the failed election.  相似文献   
155.
Novel synthetic opioids contribute considerably to the opioid epidemic, especially with the frequent emergence of structurally similar compounds. This case report describes a fatal intoxication involving 2-methyl AP-237. A 54-year-old Caucasian male was found deceased from an apparent drug overdose. A plastic container labeled “2MAP” and a cut straw were found in the decedent's backpack at the scene. A white substance found in the container tested positive for fentanyl by field testing. According to his medical history, the decedent was treated for a drug overdose 3 years prior to his death. With no diagnostic findings at autopsy, the case was submitted for toxicological analysis. An unknown substance was detected in peripheral blood and urine using gas chromatography with nitrogen phosphorous detection (GC-NPD). Further testing was conducted using gas chromatography–mass spectrometry (GC–MS) and liquid chromatography-quadrupole-time-of-flight mass spectrometry (LC-QTOF-MS) which confirmed the presence of 2-methyl AP-237 and potential metabolites in blood and urine. Quantitation by GC-NPD revealed concentrations of 2-methyl AP-237 in blood and urine at 480 ng/mL and 4200 ng/mL, respectively. The toxicological analysis also identified and quantitated alprazolam in the blood at 55 ng/mL. Additionally, the metabolism of 2-methyl AP-237 was investigated and three hydroxylated metabolites were identified in peripheral blood and urine. Limited literature is available for the detection and quantitation of 2-methyl AP-237 in postmortem specimens. Given the toxicological findings with unremarkable autopsy findings, this case is an example of a fatal intoxication involving 2-methyl AP-237.  相似文献   
156.
When iron-based tools, such as knives or guns, are held, traces of iron can transfer to the skin. However, no previous studies have been published regarding the effect of the elapsed contact time on the transfer of iron species with different valences to the palm. Compared with 3-(2-pyridyl)-5,6-diphenyl-1,2,4-triazine (PDT), 2,4,6-tri(2′-pyridyl)-1,3,5-triazine (TPTZ) was found to exhibit a higher sensitivity to iron(II) spectrophotometrically. This work employed 2,4,6-tri(2′-pyridyl)-1,3,5-triazine (TPTZ) and UV spectrophotometry to determine the amounts of iron(II), iron(III), and total iron transferred to human palms from iron tools. It was found that the palmar moisture level was an important factor in determining the amounts of total iron, including iron(II), transferred to the palm. For identical contact times, the amounts of total iron transferred to the palm was proportional to the palmar moisture, and the difference between the maximum and minimum amounts was 12 μg per hand. However, the amounts of iron(II) transferred to the palm gradually decreased over time for low palmar moisture levels, but steadily increased over time for high palmar moisture levels. Additionally, for average levels of palm moisture, the amounts of iron(II) and iron(III) transferred to the palm gradually decreased and increased, respectively, with longer contact times. Notably, this research could serve as a theoretical basis and guide for the detection of trace iron species with different valences on human palms for criminal investigations.  相似文献   
157.
Abstract

Far from having faded away, ten years after its formal adoption, the responsibility to protect (R2P), is arguably more relevant than ever. In the current overall context of protection crises, heightened in severity by the emergence of violent extremists, R2P has changed the way in which the international community characterises situations that involve protection failures, and has raised expectations about what should occur when atrocity crimes have been committed or are imminent. UN member states now agree that prevention is at the core of R2P, that international action should employ the full range of diplomatic, political and humanitarian measures, and that military force should only be considered as a measure of last resort. While there is continued contestation about particular aspects of R2P – as there is over much older normative advancements, such as human rights – R2P has helped to forge political consensus and build new institutional capacity to prevent and respond to atrocity crimes.  相似文献   
158.
Abstract

Russia’s predominantly suspicious and even negative attitudes toward R2P are closely related to its traditional attachment to the notion of sovereignty, but its reluctance to ‘bless’ the use of force with R2P also serves as a pretext to cover various instrumental goals. Russia’s more assertive foreign policy has exacerbated this trend. Disagreements stem from differences between Russia and the West both in their conceptual approaches to security and in their assessments of specific cases. In particular, Russia has an existential concern over possible application of R2P by extra-regional actors in its immediate post-Soviet vicinity. However, in the conflicts around South Ossetia (2008) and Crimea / Southeastern Ukraine (2014-), there was a noticeable trend to refocus R2P-related arguments in support of Russia’s own actions. By and large, R2P continues to be perceived as a Western attempt to establish certain rules of behaviour which require caution and prudence. Nevertheless, more positive attitudes do not seem impossible. To play a prominent role in the evolving international system, Russia will have to make the R2P segment of its foreign policy more salient and overcome the lag in promoting this concept as a working tool indispensable for cooperative and responsible leadership.  相似文献   
159.
This article analyses French executives' and lawmakers' legitimisations of the intervention in Libya with the aim of understanding the discursive construction of intervention. It investigates the arguments in favour of intervention and the oppositions they were confronted with. To these arguments belong a re-evaluated democratic legacy of France, an identification with the Libyan people, and a debate on Responsibility to Protect and the rule of law in world politics, which have a broader relevance for French actorness abroad. The article applies the Essex School discourse theory and techniques from Interpretive Policy Analysis on executive speeches and parliamentary documents for structuring the debate and for estimating the strength of ideas in their interdiscursive configuration. An ideal-typical explanation of the legitimisation of intervention and of the choice of one policy over another is made. The article argues that going to war in Libya equated to a question of cultural appropriateness.  相似文献   
160.
This article defends the Responsibility to Protect (R2P) doctrine (adopted by the United Nations in 2005) against critiques by Fabrice Weissman in this journal, and against similar criticisms of humanitarian intervention and human rights norms made by postmodern thinkers in the Nietzschean tradition, such as Alain Badiou and Anne Orford. I argue against Weissman that R2P can be effective in stopping or preventing mass atrocities, and in particular that opposition to military intervention in Syria during the 2013 debates was a terrible mistake. Moreover, the moral ground for humanitarian aid efforts is the same as the basis for forceful rescue from mass slaughter, ethnic cleansing, and persecution (when other conditions of just war can be met). Weissman's critiques misinterpret just war theory on key points and rely on inflated rhetorical strategies inspired by extreme forms of cultural and moral relativism that are intellectually bankrupt—both in blaming “Western imperialism” for most crimes against humanity committed by tyrants, and in leaving hundreds of thousands without the only protection that could prevent their murder and exile. These extreme positions and the strained rhetorical devices used to defend them do not deserve the wide respect they command in some parts of academia.  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