全文获取类型
收费全文 | 30692篇 |
免费 | 732篇 |
国内免费 | 5篇 |
专业分类
财政金融 | 4584篇 |
工业经济 | 1705篇 |
计划管理 | 3558篇 |
经济学 | 5283篇 |
综合类 | 380篇 |
运输经济 | 175篇 |
旅游经济 | 432篇 |
贸易经济 | 3640篇 |
农业经济 | 1253篇 |
经济概况 | 3427篇 |
水利工程 | 6935篇 |
信息产业经济 | 1篇 |
邮电经济 | 56篇 |
出版年
2021年 | 235篇 |
2020年 | 313篇 |
2019年 | 479篇 |
2018年 | 708篇 |
2017年 | 682篇 |
2016年 | 714篇 |
2015年 | 404篇 |
2014年 | 672篇 |
2013年 | 2764篇 |
2012年 | 1033篇 |
2011年 | 1083篇 |
2010年 | 790篇 |
2009年 | 870篇 |
2008年 | 937篇 |
2007年 | 961篇 |
2006年 | 851篇 |
2005年 | 780篇 |
2004年 | 790篇 |
2003年 | 549篇 |
2002年 | 601篇 |
2001年 | 545篇 |
2000年 | 532篇 |
1999年 | 538篇 |
1998年 | 474篇 |
1997年 | 513篇 |
1996年 | 497篇 |
1995年 | 452篇 |
1994年 | 448篇 |
1993年 | 477篇 |
1992年 | 489篇 |
1991年 | 480篇 |
1990年 | 416篇 |
1989年 | 401篇 |
1988年 | 385篇 |
1987年 | 375篇 |
1986年 | 367篇 |
1985年 | 541篇 |
1984年 | 507篇 |
1983年 | 481篇 |
1982年 | 440篇 |
1981年 | 410篇 |
1980年 | 475篇 |
1979年 | 419篇 |
1978年 | 350篇 |
1977年 | 343篇 |
1976年 | 316篇 |
1975年 | 340篇 |
1974年 | 281篇 |
1973年 | 299篇 |
1972年 | 212篇 |
排序方式: 共有10000条查询结果,搜索用时 468 毫秒
111.
This paper applies principles of transition to land tenure and squatting in South Africa. Political transition in South Africa reassigned political property rights, which produced contestable, and rent‐seeking incentives for squatting as a means to privatize land and redistribute wealth. Government failure to establish and protect private property rights in a squatter camp resulted in common‐pool problems that resisted private and public resolution with consequent rent dissipation and social loss. In response to this retreat from duty, informal agents emerged to claim their own share of the prize. Without enforceable rules of capture, the growth of squatter camps in South Africa will continue. JEL classification: D7, H8, K1, K4, R1, R4. 相似文献
112.
HYDCOND: A Computer Program to Calculate Hydraulic Conductivity from Grain Size Data in Saudi Arabia
Hydrogeologists always look for reliable techniques to determine the hydraulic conductivity of the aquifers with which they are concerned, for better groundwater management and conservation. The use of grain size distribution for unconsolidated aquifer materials is considered feasible and sound. Several empirical equations to calculate hydraulic conductivity using grain size distribution are well established in the literature. The present paper describes a computer program, HYDCOND, which is designed to calculate hydraulic conductivity using grain size data. In addition, the program calculates grain size statistics and classifies the aquifer materials in terms of their main size percentage. HYDCOND is menu-driven, interactive and user friendly program. It was tested extensively and successfully using materials from Minjur aquifer in central Saudi Arabia. The results were found to be reliable and comparable to those obtained using other, costly techniques. HYDCOND can be implemented successfully to calculate hydraulic conductivity in all types of aquifers in Saudi Arabia and other regions of the world. 相似文献
113.
114.
Search and Liquidity in Single-Family Housing 总被引:5,自引:0,他引:5
A two-stage least squares model of housing prices is estimated with data collected from 3358 single-family home transactions. The results provide evidence for an optimal marketing period and indicate that a liquidity premium is priced in single-family home sales. Consistent with the hypothesis derived from economic search models, the model shows higher selling prices for houses having longer expected marketing periods. The model also shows a price premium for houses that sell faster than expectations. This effect supports the concept that liquidity is a value-enhancing characteristic. 相似文献
115.
Christopher P. A. Bennett Ricardo A. Godoy 《Bulletin of Indonesian Economic Studies》1992,28(1):85-99
Improving the quality of Indonesia's coffee exports has been a priority of government and the Association of Indonesian Coffee Exporters for some years. Efforts to achieve this objective have, however, been hampered by misconceptions about the reasons why coffee producers and traders at each point in the marketing network do not deliver a higher quality product. The research reported here shows that price premia for higher quality coffee are not large enough to encourage greater quality enhancement. The world market for low to medium grades, used in the production of instant coffee, is much larger than that for high-quality coffee, and this preference is transmitted in the form of low incentives to improve the product. Failure to understand this has led to government policies which at best do not solve the quality problem and at worst exacerbate it. 相似文献
116.
Daniel R. Denison Jane E. Dutton Joel A. Kahn Stuart L. Hart 《Journal of Management Studies》1996,33(4):453-474
This paper explores the relationship between organizational context and the interpretation of strategic issues by examining the hypothesis that CEOs' interpretations of foreign investment in the USA are influenced by the organizational context in which they are embedded. Three aspects of organizational context - the global business experience of the firm; the firm's level of organizational inertia (as represented by firm age and size); and the resources available for responding - are examined as predictors of CEOs' perceptions of foreign investment as a threat or an opportunity. Analysis of data from 320 organizations, controlled by industry, shows that global business experience, firm size, and perceived capability are significant predictors of the perception of threat and opportunity. the discussion addresses the implications of these findings for future research on issue interpretation and organizational context. 相似文献
117.
Trends in Hydrological Parameters of a Southern Brazilian Watershed and its Relation to Human Induced Changes 总被引:5,自引:1,他引:4
Moraes Jorge M. Pellegrino Giampaolo Q. Ballester Maria V. Martinelli Luiz A. Victoria Reynaldo L. Krusche Alex V. 《Water Resources Management》1998,12(4):295-311
The Piracicaba river basin is a subtropical watershed located in the southeastern region of Brazil. With an area of 12 400 km2, the basin is a typical example of new landscape resulting from development in tropical and sub-tropical regions: establishment of intensive industrial and agricultural processes were followed by significant population growth and water management. This scenario has led to significant increase in water demand and decrease in water quality. The main objective of this study is the detection of changes in the patterns of flow and precipitation in the basin, and its possible relation to man-induced changes. Statistical analyses were performed on records of precipitation, evapotranspiration and streamflow, from 1947 to 1991. Precipitation and evapotranspiration totals showed significant increasing trends for the entire basin. From eight streamflow gauge stations, half showed significant decreasing trend. The most probable cause of such trends is the export of water from the basin to the metropolitan region of São Paulo city. 相似文献
118.
Kent D. Bimson Linda Boehm Burris James A. Terrel 《International Journal of Intelligent Systems in Accounting, Finance & Management》1992,1(2):77-91
Commercial project management systems focus on preproject planning and after-the-fact documentation, but not on the dynamic problem solving required in day-to-day project management. Yet the need for risk-oriented management is clear. To understand and control project risks, managers must be able to identify problems as they occur, immediately assess their downstream impacts, and plan a course of action. The Advanced Risk Management System (ARMS) is a prototype system built to address the issues of identifying, analyzing, prioritizing, monitoring, and controlling project risk. ARMS uses expert systems, data base management, and hypermedia technologies to capture and classify project schedule problems, to determine their semantic impacts to future activities, and to alert appropriate project personnel in advance of problem occurrence. 相似文献
119.
Anmar W. Sabri Zainab H. Ali Serwan F. Shawkat Lamia A. Thejar Thaer I. Kassim Khalid A. Rasheed 《河流研究与利用》1993,8(3):237-250
The influences of the Samarra impoundment on the ecology of the downstream sector of the river Tigris are investigated. Zooplankton were collected monthly from July 1987 to July 1988. It was found that zooplankton were most abundant during high river discharges in March. During the month of low river discharge, September, the zooplankton population was greatly reduced immediately below the barrage and remained so to the last downstream station. Several factors seem to explain such differences. The high discharge from the impoundment was found to be the dominating factor and may flush the small backwaters in which zooplankton were abundant, thus increasing the population in the river. Zooplankton species vary in their ability to sustain populations in the river, variations which are due mainly to species-specific characteristics. 相似文献
120.
Customers are sensitive to the flavour of water. Customers evaluate drinking water based on their expectations, on experiences with their usual drinking water and on experiences with alternative waters. The Philadelphia Water Department provides one example of success in developing a better understanding of customer perceptions and attitudes about tap water taste and odour. Philadelphia found that customers do communicate in ways that water utilities can understand. Water utilities can enhance that communication and collect useful data. In addition, water utilities can characterise their tap water flavour, track it for changes and correlate changes to customer complaints. 相似文献