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   153879篇
  免费   3788篇
  国内免费   27篇
财政金融   25937篇
工业经济   11628篇
计划管理   22028篇
经济学   29880篇
综合类   1479篇
运输经济   967篇
旅游经济   2524篇
贸易经济   23776篇
农业经济   6163篇
经济概况   17154篇
水利工程   15894篇
信息产业经济   8篇
邮电经济   256篇
  2021年   1082篇
  2020年   1837篇
  2019年   2676篇
  2018年   2816篇
  2017年   2884篇
  2016年   3182篇
  2015年   2401篇
  2014年   3834篇
  2013年   16471篇
  2012年   4897篇
  2011年   4729篇
  2010年   4086篇
  2009年   4749篇
  2008年   4362篇
  2007年   3845篇
  2006年   4131篇
  2005年   4025篇
  2004年   3648篇
  2003年   3137篇
  2002年   3123篇
  2001年   3002篇
  2000年   2808篇
  1999年   2734篇
  1998年   2590篇
  1997年   2674篇
  1996年   2522篇
  1995年   2298篇
  1994年   2287篇
  1993年   2260篇
  1992年   2343篇
  1991年   2222篇
  1990年   2076篇
  1989年   1920篇
  1988年   1823篇
  1987年   1842篇
  1986年   1851篇
  1985年   2648篇
  1984年   2551篇
  1983年   2345篇
  1982年   2215篇
  1981年   2152篇
  1980年   2161篇
  1979年   2078篇
  1978年   1885篇
  1977年   1822篇
  1976年   1646篇
  1975年   1484篇
  1974年   1400篇
  1973年   1404篇
  1972年   1103篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Growing urbanisation in South Africa is reflected in burgeoning Working class and informal township settlements on the fringes of its major towns and cities. Paired with this is an increasing reliance on cash as the primary means of economic transaction, which has in turn stimulated the growth of micro-enterprise business activities within the township context. This article discusses the findings of an eight-township small-area census which occurred between 2010 and 2013 in Cape Town, Johannesburg, Ekurhuleni and Durban townships representing 250 000 residents. The researchers were able to establish the scope and scale of informal food and drink retailing in these localities. Of the 10 049 micro-enterprises located in the study, some 3966 (or 39% of the total) trade in food. These include enterprises in primary production, fresh produce retailing, grocery retailing from house and spaza shops, and informal foodservice enterprises. Food is the basis for much township informal business and plays an important role in making food increasingly affordable and locally accessible, and in creating cash employment. The article builds on the knowledge base of the township informal economy role in bolstering food security needs for the marginalised.  相似文献   
2.
ABSTRACT

This paper aims to explore the conceptual potential of the Deleuzian notion of the encounter in order to better understand the genealogy of opportunities. We adopt a processual perspective of opportunities. In order to translate this notion to the domain of entrepreneurship, we analysed and interpreted Jean-Marc Vallée’s Dallas Buyers Club. This film follows the creation of the first club in the United States that illegally allowed HIV-positive people to supply themselves with foreign antiretroviral drugs from Mexico or Japan. The article highlights encounters in this process that disturb the entrepreneur’s belief systems and allow him or her to be open to potential opportunity. It finally explores how the encounter may improve our understanding of the political becoming of opportunities within the entrepreneurial process.  相似文献   
3.
This study back-tests a marginal cost of production model proposed to value the digital currency Bitcoin. Results from both conventional regression and vector autoregression (VAR) models show that the marginal cost of production plays an important role in explaining Bitcoin prices, challenging recent allegations that Bitcoins are essentially worthless. Even with markets pricing Bitcoin in the thousands of dollars each, the valuation model seems robust. The data show that a price bubble that began in the Fall of 2017 resolved itself in early 2018, converging with the marginal cost model. This suggests that while bubbles may appear in the Bitcoin market, prices will tend to this bound and not collapse to zero.  相似文献   
4.
The United Nations Watercourses Convention entered into force on 17 August 2014, following a long and complex journey that dates back to 1970 when the UN referred the matter to its legal arm, the International Law Commission. This article follows the Convention through that long and turbulent road, examines its main provisions and analyses the reasons for the delay of its entry into force. It concludes by answering the question of why entry into force of the Convention should indeed matter.  相似文献   
5.
Forward guidance can be provided as an unconditional promise, i.e. commitment to a specific low policy rate. Alternatively, the promise may include an escape clause, i.e. a condition defining the state of the economy under which the central bank would not keep such a low rate and, instead, it would revert to setting policy under discretion. The escape clause can be expressed as a threshold in terms of a specific variable. The present paper shows that, when such a threshold is expressed in terms of an endogenous variable (e.g. output, inflation), there are cases where it becomes impossible for the central bank to act in a way that is consistent with its promise. Consistency imposes limits on the policy rate that can be set since reverting immediately to the optimal discretionary rate can be incompatible with exceeding the threshold.  相似文献   
6.
ABSTRACT

Does the South African Constitution constrain or empower government, courts and citizens in addressing systemic social and economic inequalities? This article argues that the Constitution is explicitly ‘transformative’, but is an enabling document, providing ‘scaffolding’ for political and legal activities. It is government, strong institutions and civil society that are ultimately responsible for securing its equality aspirations. Here the Constitution admits of different understandings of equality and different economic and social policy choices. This article identifies these contested meanings of equality and suggests that a liberal egalitarian/social democratic version is dominant in policy choices and the jurisprudence of the Constitutional Court. It illustrates this with reference to the Court’s jurisprudence on equality, and suggests that more radical and transformative interpretations remain possible. However, it concludes that we cannot escape politics, the need for good policy choices and effective implementation and enforcement.  相似文献   
7.
8.
Demand for disclosures on environmental, social, and governance (ESG) issues has increased dramatically. Using corporate political spending disclosures as our setting, we conduct a detailed inquiry of 541 political spending‐related shareholder proposals from 2004 to 2012 to highlight the role of shareholder activism as a mechanism to motivate ESG disclosure. Unlike earlier studies, we examine both proposals that went to a vote and proposals that were withdrawn by the activist, allowing us to assess more comprehensively the success of shareholder activism. We find that 20 percent of firms targeted by disclosure proposals begin disclosing in the subsequent year, although implementation rates vary by proposal type—8 percent for proposals subject to a vote versus 56 percent for proposals withdrawn. The sponsor is also important: unions and public pension funds are less likely than other activists to target firms with agency problems and are less successful in having proposals withdrawn, and the implementations they obtain are viewed more negatively by the broader investor base. Our findings highlight shareholder proposals as one mechanism through which investors can successfully express their preferences for corporate disclosure policies. Given activists' long‐standing interest in environmental and social disclosure policies, we believe our findings generalize to a broader set of ESG disclosures.  相似文献   
9.
Dreissenid mussel veligers compose a substantial component of pelagic biomass in the Great Lakes, yet their dynamics are poorly understood. To evaluate seasonal, spatial, and inter-annual variation in veliger density, we used a 64-μm mesh plankton net (2008, 2013–2016) and a 153-μm mesh plankton net (2007–2016) to collect dreissenid veligers at nearshore (15–25?m depth), transitional (45?m) and offshore (93–110?m) sites in southeast Lake Michigan during March–December. We also evaluated trends in density of recently settled mussels relative to veliger abundance and the density of the standing stock of adult mussels. Veliger density peaked during both summer and fall at all sites, but peak densities in summer were generally higher nearshore, whereas peak densities in the fall were generally higher offshore. The density of veligers in the 153-μm net was overall 28% of that in the 64-μm net, but there was high variability in this comparison among months. Smaller veligers were much more abundant in the 64-μm net, but there was little difference in the size distribution and abundance between nets for the 210–300?μm size classes. Thus, the 153-μm net could still be a useful tool for assessing density trends of larger veligers just prior to their settlement. Newly settled mussels (≤2?mm) were most abundant in summer or fall at the nearshore and offshore sites but were nearly absent at the transitional site despite the high density of veligers there. Factors other than veliger density must play an important role in mussel recruitment.  相似文献   
10.
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