全文获取类型
收费全文 | 151973篇 |
免费 | 4454篇 |
国内免费 | 40篇 |
专业分类
财政金融 | 26020篇 |
工业经济 | 11594篇 |
计划管理 | 21935篇 |
经济学 | 29379篇 |
综合类 | 1486篇 |
运输经济 | 961篇 |
旅游经济 | 2496篇 |
贸易经济 | 23641篇 |
农业经济 | 6114篇 |
经济概况 | 17022篇 |
水利工程 | 15534篇 |
信息产业经济 | 7篇 |
邮电经济 | 278篇 |
出版年
2021年 | 1082篇 |
2020年 | 1821篇 |
2019年 | 2667篇 |
2018年 | 2746篇 |
2017年 | 2843篇 |
2016年 | 3114篇 |
2015年 | 2401篇 |
2014年 | 3823篇 |
2013年 | 16365篇 |
2012年 | 4807篇 |
2011年 | 4620篇 |
2010年 | 4033篇 |
2009年 | 4678篇 |
2008年 | 4282篇 |
2007年 | 3708篇 |
2006年 | 4011篇 |
2005年 | 3965篇 |
2004年 | 3565篇 |
2003年 | 3115篇 |
2002年 | 3110篇 |
2001年 | 2981篇 |
2000年 | 2832篇 |
1999年 | 2707篇 |
1998年 | 2568篇 |
1997年 | 2658篇 |
1996年 | 2476篇 |
1995年 | 2269篇 |
1994年 | 2279篇 |
1993年 | 2259篇 |
1992年 | 2353篇 |
1991年 | 2223篇 |
1990年 | 2051篇 |
1989年 | 1918篇 |
1988年 | 1816篇 |
1987年 | 1839篇 |
1986年 | 1857篇 |
1985年 | 2639篇 |
1984年 | 2548篇 |
1983年 | 2343篇 |
1982年 | 2236篇 |
1981年 | 2171篇 |
1980年 | 2170篇 |
1979年 | 2106篇 |
1978年 | 1912篇 |
1977年 | 1832篇 |
1976年 | 1647篇 |
1975年 | 1501篇 |
1974年 | 1401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 375 毫秒
151.
Robin Johnson George E. Rossmiller Frances Sandiford‐Rossmiller 《The Australian journal of agricultural and resource economics》2003,47(2):261-274
The present paper was inspired by and is a response to the Rola-Rubzen, Hardaker and Dillon paper 'Agricultural economists and world poverty: progress and prospects' (Rola-Rubzen et al. 2001). It is agreed that the position of agricultural economists in foreign aid and poverty programs has declined over recent decades. Such a feeling of guilt and remorse expressed by the above authors does indeed create considerable 'angst'. A major reason for this state of affairs lies in 'the flavour of the month' approach of the development agencies. These include women in development, gender-based farming systems research, household nutrition and food security, people participation, and targeting the poorest of the poor. These fads have driven disciplinary considerations to the wall and the more widely-defined objectives have reduced the drive for economic efficiency. We argue there is still a place for better designed and delivered assistance programs within the wider framework of assistance that has become fashionable. Greater application of institutional principles in both the political processes associated with assistance and the implementation agencies would improve the outcomes of many projects. Particular attention would need to be given to the interface between the development agencies and recipient governments. The present paper picks up on the market failure aspects of agriculture's rather poor contribution to development, and develops a wider perspective in terms of the new institutional economics and a continuing role for the agricultural economist. 相似文献
152.
153.
D. R. Myddelton 《Economic Affairs》2003,23(1):2-6
Major tax reform to simplify the UK tax system is possible. Merging income taxes, social security taxes and corporation tax into only a single flat-rate of tax on all incomes would be a radical start. Avoiding taxes on income and expenditure which are 'too high' requires major reductions in government spending, mainly on the welfare state. Given the political will, over a period of years we really can hugely improve the UK tax system. 相似文献
154.
Lake Chivero: A management case study 总被引:1,自引:0,他引:1
C. H. D. Magadza 《Lakes & Reservoirs: Research and Management》2003,8(2):69-81
Lake Chivero in Zimbabwe was shown to be hypereutrophic. Historical data showed that the eutrophication process had been arrested in the late 1970s. However, a combination of poor planning, multiplicity of jurisdiction, mismatch between rate of urbanization and waste management investment, recent changes in the local climate and a permissive, immature political system that called for no public accountability resulted in environmental management breakdown leading to hypereutrophication of the lake. The case of Lake Chivero is presented as an example of a wider global issue regarding the status of environmental management in competition with other priorities in emerging democracies. 相似文献
155.
The decline in private health insurance coverage over the period 1989–95 is analysed using the ABS National Health Surveys. Individuals' health status and health risk behaviours are found to be significant determinants of their decision to purchase private health insurance. At a point in time, the pool of the insured is very heterogeneous, with a mix of both good and bad health risks. It is found that the decline in insurance coverage over the period 1989–95 coincided with an increase in the degree of 'adverse selection' within the insured population. 相似文献
156.
Y Terashima H Ozaki R R Giri T Tano S Nakatsuji R Takanami S Taniguchi 《Water science and technology》2006,54(8):55-63
Environmental pollution by low concentrations of 2,4-Dichlorophenoxyacetic acid (2,4-D) is a concern these days due to ever increasingly stringent regulations. Photocatalysis with immobilized TiO2 fiber is a promising oxidation method. Laboratory experiments on photocatalytic degradation of 0.045 mmol l(-1) 2,4-D with the world's first high-strength TiO2 fiber catalyst were carried out in a continuous flow reactor in which the degradations were, in general, similar to those with high 2,4-D concentrations investigated elsewhere. Degradation and mineralization of 2,4-D were significantly enhanced with no initial pH adjustments. The rate constants for total organic carbon (TOC) without pH adjustment were about two-fold bigger than the pH adjustment cases. CO2 gas measurement and carbon mass-balance were carried out for the first time, where about 34% organic carbon converted into CO2 gas during four-hour oxidation. 2,4-Dichlorophenol (2,4-DCP), phenol, benzyl alcohol and two unknowns (RT = 2.65 and 3.78 min.) were detected as aromatic intermediates while Phenol was the new aromatic in HPLC analysis. Dechlorination efficiencies were high (> 70%) in all the cases, and more than 90% efficiencies were observed in chloride mass balance. Bigger flow rates and solution temperature fixed at 20 degrees C without pH adjustment greatly enhanced 2,4-D mineralization. These results can be an important basis in applying the treatment method for dioxin-contaminated water and wastewater. 相似文献
157.
V. N. Durcheva S. M. Puchkova 《Power Technology and Engineering (formerly Hydrotechnical Construction)》2006,40(2):71-78
Operation of the dam in a transitional mode is described.
__________
Translated from Gidrotekhnicheskoe Stroitel’stvo, No. 1, January 2006, pp. 8–15. 相似文献
158.
159.
Exploring the Intensive and Extensive Margins of World Trade 总被引:1,自引:0,他引:1
World trade evolves at two margins. Where a bilateral trading relationship already exists it may increase through time (intensive
margin). But trade may also increase if a trading bilateral relationship is newly established between countries that have
not traded with each other in the past (extensive margin). We provide an empirical dissection of post–World War II growth
in manufacturing world trade along these two margins. We propose a “corner-solutions version” of the gravity model to explain
movements on both margins. A Tobit estimation of this model resolves the so-called “distance puzzle”. It also finds more convincing
evidence than recent literature that WTO-membership enhances trade.
JEL no. F12, F15 相似文献
160.