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   1600篇
  免费   115篇
各国政治   23篇
工人农民   5篇
世界政治   12篇
外交国际关系   254篇
法律   1079篇
中国共产党   11篇
中国政治   31篇
政治理论   109篇
综合类   191篇
  2024年   6篇
  2023年   11篇
  2022年   16篇
  2021年   28篇
  2020年   54篇
  2019年   62篇
  2018年   55篇
  2017年   25篇
  2016年   28篇
  2015年   29篇
  2014年   43篇
  2013年   41篇
  2012年   68篇
  2011年   61篇
  2010年   56篇
  2009年   192篇
  2008年   276篇
  2007年   323篇
  2006年   81篇
  2005年   44篇
  2004年   38篇
  2003年   37篇
  2002年   33篇
  2001年   23篇
  2000年   22篇
  1999年   15篇
  1998年   7篇
  1997年   4篇
  1996年   5篇
  1995年   2篇
  1994年   3篇
  1993年   4篇
  1992年   5篇
  1991年   3篇
  1990年   1篇
  1989年   4篇
  1988年   3篇
  1987年   1篇
  1986年   2篇
  1985年   2篇
  1981年   1篇
  1978年   1篇
排序方式: 共有1715条查询结果,搜索用时 15 毫秒
991.
Suicide is a worldwide health problem with multiple causes, including genetic factors. The major histocompatibility complex (MHC) is represented by an assembly of gene encoding the human leukocyte antigen (HLA). The purpose of our study was to determine associations between the HLA profiles and predisposition for suicidal behavior. We harvested blood samples from persons with history of suicidal attempts (case group) and persons never exhibiting such behavior (control group). The DNA was extracted and amplified via polymerase chain reaction (PCR) to determine the HLA-DQB1 profiles. Statistical data processing was performed with the Epi Info program. We found that the presence of the HLA-DQB1*02 allele increases the risk of suicidal behavior, while HLA-DQB1*05 alleviates such risk. The genotype that presented the most increased risk for suicidal behavior was found to be HLA-DQB1*02/HLA-DQB1*03. Our study has demonstrated the presence of several associations between HLA profiles and suicidal behavior.  相似文献   
992.
The decline of carbon intensive technologies is a key element in the ongoing energy transition and our attempts to tackle climate change. At the same time, our understanding of technology decline and of the associated policies and politics is still limited. This paper builds on the sustainability transitions perspective, a novel approach to analyze socio‐technical transformation, including the complex interplay of policy and technology change. We study the decline of coal‐fired power generation in the United Kingdom from 2000 to 2017 by analyzing the discourse in The Guardian. We find scientists and environmental NGOs criticizing coal for climate and health reasons. Government and incumbent businesses tried to re‐legitimate coal but eventually, their resistance collapsed and coal was almost completely abandoned in just a few years. Particularly devastating for coal were failed promises around carbon capture and storage, rapid diffusion of wind energy, and pressure from various policies. This study contributes to better understanding the contested nature of decline, and the interplay of discursive struggles, technology change, and public policy in sustainability transitions.  相似文献   
993.
This study applies a narrative lens to policy actors’ discursive strategies in the Scottish debate over fracking. Based on a sample of 226 newspaper articles (2011–2017) and drawing on key elements of the narrative policy framework (NPF), the research examines how policy coalitions have characterized their supporters, their opponents, and the main regulator (Scottish government). It also explores how actors have sought to expand or contain the scope of conflict to favor their policy objectives. Empirically, only the government strives for conflict containment, whereas both pro‐ and anti‐fracking groups prioritize conflict expansion through characterization contests and the diffusion and concentration of the costs/risks and benefits of fracking. In theoretical terms, the study proposes that Sarah Pralle’s conflict management model, which emphasizes symmetrical strategies of conflict expansion by both coalitions, is a potential tool to revise extant NPF expectations about the different narrative strategies of winning and losing coalitions. Moreover, the fact that policy actors mostly employ negatively rather than positively framed characters in their narratives may be a valid expectation for similar policy conflicts, particularly under conditions of regulatory uncertainty.  相似文献   
994.
Trust is a key component of democratic decision‐making and becomes even more salient in highly technical policy areas, where the public relies heavily on experts for decision making and on the information provided by federal agencies. Research to date has not examined whether the members of the public place different levels of trust in the various agencies that operate within the same policy subsystem, especially in a highly technical subsystem such as that of nuclear energy and waste management. This paper explores public trust in multiple agencies operating within the same subsystem, trust in each agency relative to aggregate trust across agencies that operate within the nuclear waste subsystem, and trust in alternative agencies that have been suggested as possible players in the decision‐making process. We find that trust accorded to different federal agencies within the nuclear waste subsystem varies. The variation in trust is systematically associated with multiple factors, including basic trust in government, perceptions about the risks and benefits of nuclear energy/waste management, party identification, and education. These findings have significant implications for research on public trust in specific government agencies, alternative policy entities, and for policy makers who want to design robust and successful policies and programs in highly technical policy domains.  相似文献   
995.
How do disruptions in basic public service delivery shape people’s perceptions of politicians? We offer evidence from the July 2012 blackout in India, the largest in human history. Using data from the India Human Development Survey, we compare confidence in politicians between households that were surveyed during the outage and affected by it (treatment) and only days before it (control). Balance statistics show that the treatment and control groups are statistically indistinguishable, and further tests indicate that there was no disturbance to the pattern of surveying. Far from undermining public confidence in politicians, the outage increased it, as citizens reacted to the anxiety created by the crisis. The implications are normatively troubling, as politicians seem to have reaped benefits from disruptions in public service delivery.  相似文献   
996.
目的 观察健脾通里中药芪黄煎剂对大鼠胃切除创伤模型肠黏膜紧密连接蛋白的影响,并探讨其作用机制。方法 将45只大鼠随机分为假手术组、标准肠内营养组、中药组,每组15只。假手术组大鼠仅腹壁切开,未切除胃;其余两组采用胃切除手术方案建立大鼠模型。假手术组术后正常饮食饮水,标准肠内营养组术后注射肠内营养液,中药组注射肠内营养液+中药煎剂。干预7 d后取材,透射电镜下观察大鼠肠黏膜上皮紧密连接形态及其结构的连续性和完整性,并测量肠黏膜上皮细胞间紧密连接宽度;实时荧光定量聚合酶链式反应法检测紧密连接蛋白(zonula occludin-1,ZO-1)、封闭蛋白、咬合蛋白mRNA表达水平。结果 与假手术组比较,标准肠内营养组大鼠肠黏膜上皮细胞紧密连接宽度显著减小(P<0.05),小肠组织中ZO-1、封闭蛋白、咬合蛋白mRNA表达水平均显著下调(P<0.05);与标准肠内营养组比较,中药组大鼠肠黏膜上皮细胞紧密连接宽度显著增加(P<0.05),小肠组织中ZO-1、封闭蛋白、咬合蛋白mRNA表达水平均显著上调(P<0.05)。结论 芪黄煎剂可以减轻胃切除术后大鼠肠黏膜上皮细胞间紧密连接的损伤,其作用机制与调节ZO-1、封闭蛋白、咬合蛋白mRNA的表达有关。  相似文献   
997.
《政策研究评论》2018,35(2):213-237
In the wake of the COP21 conference in Paris, the transition to a low‐carbon energy supply remains a central issue on the political agenda. The deployment of renewable energies is often challenged by multiple issues (e.g., public acceptance, landscape protection, and so forth). Political actors try to overcome such challenges with various measures; however, the policy instruments used vary greatly in their strength. This article questions what factors lead to the adoption of strong policy instruments promoting hydroelectricity. Explanatory factors are derived from Kingdon's multiple streams framework and are analyzed with fuzzy‐set qualitative comparative analysis within the Swiss cantons. The findings show that the strength of policy promoting hydroelectricity depends on the conjunction of mainly two factors: ambitious climate targets and an already well‐established hydroelectricity sector that generates large tax revenues for the cantons. Depending on the context, the strength of left‐wing and green parties as well as the current level of exploitation play an important role with the aforementioned factors.  相似文献   
998.
《政策研究评论》2018,35(1):89-119
In 2014, the U.S. Food and Drug Administration (FDA) proposed taking a more active role in the regulation of laboratory‐developed tests (LDTs). Meanwhile, the U.S. House of Representatives embarked upon the 21st Century Cures initiative to develop legislation to expedite the development of new biotechnology innovations. During that initiative and in the public comments responding to the draft guidance, there was significant disagreement as to whether the increased FDA regulation of LDTs was beneficial or detrimental to biotechnology. Both the FDA guidance document and the 21st Century Cures Act came about due to the opening of a window of opportunity created by the convergence of circumstances. The question is whether the windows of opportunity are competing and how to resolve this competition. This study will investigate these questions through a qualitative case study. It will also provide recommendations for resolving policy disputes involving wicked problems like biotechnology policy.  相似文献   
999.
1000.
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