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51.
情感分类是一项具有较大实用价值的分类技术.它可以对网上纷繁复杂的信息进行情感倾向标注.为用户提供一个简洁的总结信息,进而为人们制定决策提供帮助,然而目前针对汉语的情感分类开展的工作并不多。提出一种基于SVM机器学习的情感分类方法,并引入基于2-POS模型的句子主观性分析方法,利用SVM进行机器学习,实现汉语评论的情感分类。实验表明这种方法能够有效地判定评论信息的情感倾向。  相似文献   
52.
为了解2013-2017年间广东省猪源葡萄球菌的耐药情况及多重耐药基因cfr的流行现状,采集生猪养殖场和交易市场猪鼻腔拭子分离葡萄球菌,采用琼脂稀释法测定分离菌株对14种抗菌药物的敏感性,并用PCR检测mecA和cfr基因的携带情况。结果显示,在采集的4099份样品中分离到葡萄球菌1485株,其中金黄色葡萄球菌173株。猪源葡萄球菌对红霉素、四环素、泰妙菌素、克林霉素、沃尼妙林和氟苯尼考耐药严重,耐药率分别为91.0%、90.2%、87.7%、84.6%、84.6%及82.0%,对利福平和利奈唑胺相对敏感,未发现万古霉素耐药菌株;庆大霉素、四环素、红霉素和环丙沙星的耐药率呈现逐年上升的趋势。在1485株葡萄球菌中,mecA和cfr的检出率分别为39.9%和12.3%。cfr阳性菌株常携带多种耐药基因,cfr基因的遗传背景也呈现多样化。结果表明,广东省猪源葡萄球菌的耐药情况严重,cfr的检出率高,应加强养殖业中抗菌药物的规范和合理使用,减缓耐药性的产生和传播。  相似文献   
53.
International research collaboration (IRC) is associated with both positive and negative effects on the performance of research in emerging economies. While some authors claim that North–South collaborations improve scientific quality and visibility for Southern countries, others claim that it may entail the reorientation of research to comply with Northern agendas. South–South collaborations are thought to increase the focus on local affairs, therefore leading to a relatively small number of scientific international publications appearing in “high quality” journals. Research on the impact of IRC beyond publications in international journals has been neglected despite the importance of other products in knowledge creation. This research uses a broad range of scientific outputs to empirically assess such assumptions and explore the outcomes of IRC in Colombia. Results from multivariate regressions and nonparametric analyses show that, contrary to common assumptions, Colombian research teams collaborating with partners from the global South report higher scientific production, while those collaborating with Northern countries seem to contribute to local knowledge the most.  相似文献   
54.
The United States is experiencing growing impacts of climate change but currently receives a limited policy response from its national leadership. Within this policy void, many state governments are stepping up and taking action on adaptation planning. Yet we know little about why some states adopt State Adaptation Plans (SAPs), while others do not. This article investigates factors that predict the emergence of SAPs, both in terms of policy adoption and policy intensity (goal ambitiousness). Applying the diffusion of innovation theory, I consider the relative influence of internal state characteristics, regional pressures, and test for conditional effects between government ideologies and severity of the problem. The results show interesting differences between predictors that influence policy adoption and ambitiousness. States are more motivated to adopt a policy when faced with greater climate vulnerability, have more liberal citizenry, and where governments have crossed policy hurdles by previously passing mitigation plans. The intensity of policies and goal setting, moreover, is more likely to be driven by interest group politics and diffuse through policy learning or sharing information among neighboring states in Environmental Protection Agency regions. These findings support an emerging scholarship that uses more complex dependent variables in policy analysis. These variables have the potential to differentiate symbolic from substantive policies and capture finer information about predictors of importance.  相似文献   
55.
Members of parliament are key actors for the implementation of energy transitions, such as phasing out nuclear power. Before legislators can cast their maybe decisive vote in parliament, they need to run for office and actively strive for election. This paper assesses what political candidates oppose renewable energy transitions and questions whether the energy issue matters in national elections, and thus has consequences for the implementation of new sustainable energy sources. We analyze these questions by first describing the specific characteristics of political candidates. The paper then evaluates the relevance of the energy issue for electoral success in three national elections in Switzerland (2007, 2012, and 2015). Based on candidate data from the voting advice application smartvote.ch, we find that female candidates support ETs more than men do; that especially the French‐speaking part of the country is more in favor of a nuclear phase‐out, and that younger candidates are also more open toward restructuring the energy system than older candidates are. Our models further show that the energy issue does not matter in elections, independently from its salience in the respective election campaigns. Candidates are thus relatively free to choose their position on the issue and do not have to fear consequences at the ballot. However, candidates of center parties, in contrast to the pole parties, are sensitive to the energy issue and reflect public mood in their positions.  相似文献   
56.
This article characterizes the ways in which the actors in charge of designing and implementing public policies intervene to promote the emergence of alternatives to problematic technologies. It is based on a case study conducted in Argentina that focuses on initiatives to promote the development of biological agricultural inputs in the context of increasingly controversial chemical inputs. The study spotlights the political, institutional, and semantic efforts made by policy makers and public administrations to ensure these new inputs find their way into organizations and onto their agendas. Their work consists in attenuating the boundaries between chemical and biological inputs, and reducing opposition by creating categories and organizations that downplay potential dissension and highlight the possible coexistence of technological paradigms. Contrary to what the injunctions of technological substitution suggest, we show that putting alternative technologies on the public agenda depends largely on their inclusion in institutional and regulatory infrastructures originally designed for technologies that are likely to decline. More broadly, it relies on the construction of continuity between the two types of technologies.  相似文献   
57.
Understanding what stimulates agribusiness firms to lobby the government and what makes the government responsive to lobbying are the two issues that have been discussed extensively in the debates concerning determinants of biotechnology policy. This paper examines the factors influencing agribusiness firms' lobbying and government response using econometric modeling on a new data set of 160 leading agribusiness firms in the food, feed, chemical, and seed industries in China. The results show that approximately 10% of agribusiness firms lobbied the government about biotechnology policy and regulations and over half of those that lobbied received a verbal or written acknowledgment from government agencies. Seed and feed companies are more likely to engage in lobbying than chemical companies. Owning GM patents not only has a positive impact on firms' lobbying activities, but firms with these patents are more likely to receive a government response to their lobbying efforts. The experience of selling GM products does not significantly influence lobbying activities or response from the government.  相似文献   
58.
As the emergence of nongovernmental conservation efforts generates conflict among various stakeholders, the causal story that each party articulates regarding conservation and the causes of land degradation reflects their unique interests. This study uses existing literature to evaluate causal stories surrounding a contemporary conservation effort: Montana's American Prairie Reserve. Through qualitative review of web‐based documents and newspaper articles, it generates a preliminary account of key stakeholders' causal stories. The case study suggests that parties who might be disadvantaged by ascribing responsibility for environmental harms in an adversarial fashion may instead elect to articulate causal stories that are more neutral than existing approaches might forecast. The study concludes by suggesting that further development of causal story literature may enable it to better address contemporary conservation efforts.  相似文献   
59.
The U.S. electric power sector has experienced a substantial shift of the generation mix since the turn of the century, moving from heavy reliance on coal‐powered generation to one drawing more from natural gas and, more recently, renewables. This transition has been forged by a mix of macroeconomic factors (recession and recovery); technological breakthroughs (horizontal drilling coupled with hydraulic fracturing; improvements in natural gas plant efficiency); clean energy policies at federal, state, and local levels of government; and private sector demands for carbon‐free energy sources. These factors have combined to reduce carbon emissions from electric power generation substantially this century. In this article we examine the extent of this transition, its causes, as well as the distinct American institutional factors steering it, including energy and environmental federalism, electoral politics, and the political economy of clean energy policy enactment and resistance.  相似文献   
60.
目的 研究大鼠骨骼肌挫伤后M1/M2型巨噬细胞浸润的动态变化规律结合组织学改变建立损伤时间推断方法.方法 建立大鼠骨骼肌挫伤模型,挫伤后6h、12h、24h、36h、48h、60h、72h、96h、144h、216h、336h为实验组,对照组不进行任何处理.采用HE染色法和免疫荧光多重染色方法观察骨骼肌挫伤后修复规律,...  相似文献   
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