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   3154篇
  免费   160篇
各国政治   134篇
工人农民   56篇
世界政治   87篇
外交国际关系   563篇
法律   1683篇
中国共产党   21篇
中国政治   129篇
政治理论   314篇
综合类   327篇
  2024年   4篇
  2023年   44篇
  2022年   41篇
  2021年   54篇
  2020年   124篇
  2019年   155篇
  2018年   143篇
  2017年   132篇
  2016年   100篇
  2015年   84篇
  2014年   100篇
  2013年   251篇
  2012年   161篇
  2011年   143篇
  2010年   73篇
  2009年   178篇
  2008年   238篇
  2007年   344篇
  2006年   179篇
  2005年   145篇
  2004年   129篇
  2003年   100篇
  2002年   95篇
  2001年   68篇
  2000年   60篇
  1999年   34篇
  1998年   22篇
  1997年   10篇
  1996年   10篇
  1995年   9篇
  1994年   12篇
  1993年   9篇
  1992年   10篇
  1991年   14篇
  1990年   5篇
  1989年   10篇
  1988年   8篇
  1987年   3篇
  1986年   7篇
  1985年   2篇
  1984年   1篇
  1981年   1篇
  1979年   1篇
  1978年   1篇
排序方式: 共有3314条查询结果,搜索用时 15 毫秒
131.
We conduct the first long-term experimental evaluation of a need-based financial aid program, the privately funded Wisconsin Scholars Grant. Over multiple cohorts, the program failed to increase degree completion and graduate school enrollment up to 10 years after matriculation. The program did reduce time-to-degree for some students and modestly increased the number of STEM degrees earned. The lack of robust effects raises important questions about the conditions necessary for financial aid to benefit students.  相似文献   
132.
The experience of the 2019 general election in Northern Ireland took a very different course to that of the rest of the UK and, indeed, to the pattern of electoral politics typical of the region. Coming after almost three years with no functioning devolved government, combined with intense disagreement and uncertainty about Brexit, voters were ready to give a message to the two largest parties. Both Sinn Féin and the DUP suffered losses in the election, with the headline outcome being that unionism no longer holds the majority of seats for Northern Ireland in Westminster. More generally, there was a swing from both sides towards centre ground voting, which brought significant gains for the Alliance Party and the SDLP. This article summarises the reasons for this broad trend, focussing on the conditions and electoral pacts which brought it about. It also considers what it might mean for the prospects for Irish unification, noting that a referendum on unification will only be passed by attracting votes from those who tend to see themselves as neither unionist or nationalist.  相似文献   
133.
International development agencies, with the help of the central government, support building state of art Bus Rapid Transit (BRT) in low-income Asian cities. However, BRT investment over indigenous modes of mobility is creating socio-political tensions at the local level. This article uses multi-level governance as a theoretical lens to examine the relationships among actors in BRT investment decisions in Bandung and Surabaya, Indonesia. The research finds that local stakeholders can distort national and supranational policy initiatives totally or in a way that while projects are delivered, they are of limited use to the local communities they intended to help.  相似文献   
134.
This article analyses welfare impacts of fertiliser adoption using data collected from 838 cocoa farm households in the four key cocoa-producing regions in Ghana. Using propensity score matching (PSM), the study indicates that application of fertiliser leads to significant gains in farm yields, farm income, consumption expenditure, consumption expenditure per capita, and value of productive farm assets. The article concludes that cocoa-specific programmes such as Cocoa High Technology (Cocoa Hi-tech), initiated to intensify the application of improved farm technologies such as fertiliser, should be strengthened through effective and efficient management systems.  相似文献   
135.
This article investigates trust among dairy value-chain actors to understand the innovative process in a local productive sector in Tunisia. It uses a sample of 45 smallholder farmers chosen randomly nearby existing collection centres in the region. A trust variable is constructed employing 11 ordinal variables based on principal component analysis, and institutional arrangements then modelled to examine the effect of trust on contracting decisions and cooperative membership. The results show that trust is defined by values such as “integrity”, “competence”, and “existence of credible information”, which are preconditions to sustainable contracts. The article contributes to the growing literature which considers social capital, networking and trust as determinants of farmer’s behaviour, as opposed to the classical model of rationality.  相似文献   
136.
This viewpoint reflects on how to improve the process of introducing facilitated industrial symbiosis programmes (FISPs) to small and medium enterprises (SMEs) in developing countries. Although FISPs are a long-established industrial practice, their formal introduction to SMEs in developing countries has only recently begun, mostly through support from international development agencies. Based partly on anecdotal evidence from Gauteng, South Africa, we identify six key questions which need to be addressed to improve the process of facilitating FISPs.  相似文献   
137.
The American University of Beirut's emergence as a hub of Arab national and cultural identity in the first half of the twentieth century has been well documented by historians. The simultaneous Zionist presence on campus has been largely overlooked. Zionist ideas were predominantly promoted by Palestinian Jewish students who formed a small but vocal minority at AUB prior to 1948. Faculty and non-Jewish students also regularly collaborated with and traveled to Zionist institutions in Palestine for academic, athletic, and leisure purposes. For Arab students on campus, therefore, Zionism was not an abstract concept, but rather a national identity embodied by fellow classmates and friends on campus. As the conflict in Palestine increased in the 1930s and 1940s, so too did political activism and tensions on campus between Zionist and Arab nationalist students. This article analyzes this unique period of exchange, collaboration, and friction at AUB, which came to a swift end with the outbreak of the 1948 War. By focusing on the interactions between Arab and Zionist Jewish students at AUB, I seek to extend the ‘relational’ approach towards Jewish-Arab contact beyond Palestine's borders.  相似文献   
138.
This article considers the immediate forces influencing China’s food system and food security. By immediate is meant events of the reform period, from the late 1970s to 2008. It begins by asking the question that has preoccupied specialists since the publication of Lester Brown’s Who Will Feed China? in 1995: How much arable land does China have? Is that land area sufficient to insure grain sufficiency? To insure food security? The article focuses on the human pressures on the food production environment, and then treats the effects of socioeconomic change: land, air, and water degradation. The core of the article examines six responses of the state to both perceived and actual environmental stressors: policy restricting arable land conversion, China’s one-child policy, investment in irrigation systems, the South–North Water Diversion Project, large-scale afforestation and reforestation campaigns, and the program to convert marginal agricultural lands to forests and grasslands.  相似文献   
139.
副猪嗜血杆菌抗体间接血凝检测方法的建立及应用   总被引:11,自引:2,他引:11  
将副猪嗜血杆菌(Haemophilus parasuis,HPS)血清型4、5型分离菌株经超声波破碎处理后的产物致敏醛化红细胞,建立了检测HPS抗体的间接血凝试验方法。最适反应条件为绵羊红细胞30℃醛化5 h,4、5型菌株浓缩抗原以1∶8稀释致敏红细胞。免疫猪2周后检出率达89%。对15种HPS血清型阳性血清进行检测,结果均为阳性;对猪瘟病毒、口蹄疫病毒、猪圆环病毒、猪细小病毒、猪伪狂犬病病毒、猪生殖与呼吸综合征病毒、猪肺炎支原体、猪链球菌、猪肺疫巴氏杆菌、Ⅰ相支气管败血波氏杆菌及胸膜肺炎放线杆菌阳性血清进行检测,结果均为阴性。敏感性为琼脂扩散试验的16倍。对1 665份猪血清进行检测,阳性率为47.1%。结果表明,该方法敏感性较高,特异性强,重复性好,可用于疫苗免疫后抗体水平的检测及副猪嗜血杆菌的流行病学调查。  相似文献   
140.
葡萄球菌GST-mTSST-1融合蛋白抗体间接ELISA检测方法的建立   总被引:1,自引:0,他引:1  
以纯化的金黄色葡萄球菌无毒诱变超抗原GST-mTSST-1融合蛋白作为检测抗原,通过优化ELISA反应条件,初步建立了检测血清特异性GST-mTSST-1抗体的间接ELISA方法,监测了小鼠血清中特异性GST-mTSST-1抗体水平的动态变化规律。方阵试验确定的GST-mTSST-1抗原的最适包被浓度为5.0μg/mL,血清最佳稀释倍数为1∶100,ELISA阳性反应的临界值为D490 nm≥0.219,批内和批间重复试验的变异系数均小于10%。应用该方法对试验小鼠血清进行检测,结果表明,建立的间接ELISA方法具有较高的敏感性、特异性和较好的重复性,适用于检测特异性GST-mTSST-1血清抗体。  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