全文获取类型
收费全文 | 14840篇 |
免费 | 408篇 |
国内免费 | 68篇 |
专业分类
财政金融 | 2346篇 |
工业经济 | 1062篇 |
计划管理 | 2160篇 |
经济学 | 2777篇 |
综合类 | 396篇 |
运输经济 | 84篇 |
旅游经济 | 156篇 |
贸易经济 | 1950篇 |
农业经济 | 794篇 |
经济概况 | 1865篇 |
水利工程 | 1710篇 |
信息产业经济 | 2篇 |
邮电经济 | 14篇 |
出版年
2021年 | 138篇 |
2020年 | 150篇 |
2019年 | 190篇 |
2018年 | 247篇 |
2017年 | 244篇 |
2016年 | 237篇 |
2015年 | 222篇 |
2014年 | 311篇 |
2013年 | 1313篇 |
2012年 | 467篇 |
2011年 | 519篇 |
2010年 | 431篇 |
2009年 | 480篇 |
2008年 | 485篇 |
2007年 | 456篇 |
2006年 | 462篇 |
2005年 | 469篇 |
2004年 | 359篇 |
2003年 | 302篇 |
2002年 | 254篇 |
2001年 | 278篇 |
2000年 | 258篇 |
1999年 | 236篇 |
1998年 | 229篇 |
1997年 | 242篇 |
1996年 | 256篇 |
1995年 | 237篇 |
1994年 | 230篇 |
1993年 | 192篇 |
1992年 | 218篇 |
1991年 | 236篇 |
1990年 | 202篇 |
1989年 | 169篇 |
1988年 | 167篇 |
1987年 | 140篇 |
1986年 | 188篇 |
1985年 | 258篇 |
1984年 | 263篇 |
1983年 | 261篇 |
1982年 | 226篇 |
1981年 | 236篇 |
1980年 | 202篇 |
1979年 | 217篇 |
1978年 | 188篇 |
1977年 | 161篇 |
1976年 | 146篇 |
1975年 | 134篇 |
1974年 | 130篇 |
1973年 | 101篇 |
1972年 | 102篇 |
排序方式: 共有10000条查询结果,搜索用时 359 毫秒
81.
I Kaufmann T Meyer M Kalsch T G Schmitt H W Hamacher 《Water science and technology》2007,56(5):115-124
If technologies for decentralised sanitation and reuse (DESAR) and for natural stormwater management should at least partially replace existing systems, then intensive reconstruction work becomes essential. A conversion can only be realised successively over a long period due to high construction and financial expenses and requires new strategies. This paper presents the development and practical implementation of a mathematical tool to find an optimised strategy for the realisation of alternative and more decentralised drainage and sanitation concepts in existing urban areas. The succession of construction measures (e.g. the implementation of decentralised greywater recycling) for the whole period of consideration is determined based upon a mathematical optimisation model on the condition that the favoured future state is known. The model describes the complex interdependencies of the urban water and nutrient cycle and enables the minimisation of both financial efforts and ecological impacts on the way toward the future state. The results of the implementation for a rural area in Germany show that the mathematical optimisation is an adequate instrument to support decision-making processes in finding strategies for the realisation of sustainable urban water management. 相似文献
82.
The secondary effluent from municipal plants in Korea generally represents higher BOD with lower SS. Therefore, more soluble forms of organics and NH4-N need to be removed to improve its effluent for reuse. In this study reuse possibility of secondary effluent and CSO (combined sewer overflow) using BAF (biological aerated filter) was evaluated. The tertiary application with 1.2 h EBCT, SS, BOD and COD showed stable concentrations less than 1.3, 1.3 and 6.2 mg/L, respectively. Nitrogen could be nitrified even at 7 degrees suggesting BAF can be used for a water reuse method as well as an effective add-on facility in cold regions. However, BAF was not stable with CSO application at increased flow rates suggesting CSO must be equalised prior to application. Disinfection was necessary even during normal weather conditions. 相似文献
83.
84.
85.
This paper employs the economics of shortage framework to examine post-Mao reforms in Chinese state-owned industry. Performance has been disappointing because reforms through 1985 failed to fundamentally alter economic agent behavior. The “soft” budget constraints at the enterprise and local government levels continue to generate “quantity” and “expansion” drives. The resultant inflationary pressures have necessitated administrative interventions and thwarted reform progress. The Maoist legacy of active participation by local governments in economic management is high-lighted as a major obstacle to the elimination of paternalism in state-enterprise relations. 相似文献
86.
Review of Industrial Organization - 相似文献
87.
W. Kip Viscusi 《Risk Management & Insurance Review》2004,7(1):9-24
Proposed tort reforms have focused on punitive damages and noneconomic damages, each of which pose problems for jury decision making. The U.S. Supreme Court decision in State Farm v. Campbell will greatly limit very large punitive damages awards, and will affect smaller punitive awards to a lesser degree. Noneconomic damages caps enacted by state legislatures have greatly enhanced insurance market performance. Insurers operate within the context of a highly imperfect, regulated market in which there is substantial price rigidity induced by regulation. Reform efforts should strive to establish greater predictability and stability in these awards components rather than simply being concerned with imposing specific numerical caps. 相似文献
88.
This paper is based on the traditional Austrian Theory of Capital which deals with expected values of future returns of investments over various periods of time. The longer the time period that elapses between the beginning of a production process and its end, the higher the (expected) productivity must be due to positive time preferences of individuals. This paper focuses on the uncertainty of future returns and on uncertainty preferences, instead. Based on the Hayekian idea of the dispersion of knowledge in society, it will be shown that there is a systematic relationship between the structure of capital and uncertainty. This result will be derived for a production process characterized by complete vertical integration and one which is not completely vertically integrated. The distinction between these two settings is crucial, if one accepts the distinction between an individual and a social period of production and the planning horizon which are introduced in this paper. 相似文献
89.
Angus W. Laing Alison J. Brown 《International Journal of Nonprofit & Voluntary Sector Marketing》1997,2(4):342-352
This paper examines the process of interaction between consumers and providers of dental services in terms of the key selection and evaluation criteria employed by consumers. Focusing on the United Kingdom, it examines the impact of changes in both pricing and provision on the utilisation and evaluation of dental services. Based on a questionnaire survey of dental patients, in the context of the evolving body of literature concerned with consumer behaviour in respect of services, the paper attempts to improve the current understanding of the key factors shaping consumer choice in respect of professional services. Specifically, it argues that the highly complex nature of professional services impacts on patterns of consumer behaviour, resulting in the relationship between the individual service professional and the consumer being the focus of consumer evaluation. This in turn has significant implications for the effective marketing of such professional services. 相似文献