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41.
The surface energy balance of Lake Superior was measured using the eddy covariance method at a remote, offshore site at 0.5-h intervals from June 2008 through November 2010. Pronounced seasonal patterns in the surface energy balance were observed, with a five-month delay between maximum summer net radiation and maximum winter latent and sensible heat fluxes. Late season (winter) evaporation and sensible heat losses from the lake typically occurred in two- to three-day-long events, and were associated with significant release of stored heat from the lake. The majority of the evaporative heat loss (70-88%) and sensible heat loss (97-99%) occurred between October and March, with 464 mm (2008-2009) and 645 mm (2009-2010) of evaporative water loss occurring over the water year starting October 1. Evaporation was proportional to the horizontal wind speed, inversely proportional to the ambient vapor pressure, and was well described by the ratio of wind speed to vapor pressure. This ratio remained relatively constant between the two water years, so the differences in evaporative water loss between years were largely associated with differences in lake surface conditions (e.g. water temperature, ice cover, and ice duration). Since late-season water temperature decline is driven by evaporative and sensible heat loss, the potential for a negative feedback mechanism between evaporation and ice cover is discussed.  相似文献   
42.
Global water resources are vulnerable to depletion due to the increasing demand of an ever-increasing human population. A country’s water footprint is a measure of the total volume of water needed to produce the goods and services consumed by the country, including water originating beyond its own borders. The water footprint can be a critical indicator of global water resource use, but its practical application is hindered by a lack of comparable data across national boundaries. The purpose of this article is to test the applicability of the nighttime imagery products produced by the Defense Meteorological Satellite Program’s Operational Linescan System (DMSP-OLS) for the assessment of the global water footprint. To accomplish this purpose, the average areal extent of nighttime lighting (lit area) is calculated from 1997 to 2001. Next, lit area is regressed on the total water footprint for each country, as indicated by the Water Footprint Network (WFN), to estimate that country’s total water footprint using nighttime imagery. Model residuals are analyzed at the national scale to understand the appropriateness of nighttime imagery for assessing water consumption. Results indicate strong positive correlations between lit area and total water footprint (TWF), domestic water withdrawal (DWW), and industrial water consumption (IWC) at the national scale. Overall, the analyses reveal that the rate of agricultural water consumption to total water footprint (AWCR) and population density can affect the precision of estimates when lit area is selected as a proxy to estimate water footprints.  相似文献   
43.
In "Making Competition in Health Care Work" (July-August 1994), Elizabeth Olmsted Teisberg, Michael E. Porter, and Gregory B. Brown ask a question that has been absent from the national debate on health care reform: How can the United States achieve sustained cost reductions while at the same time maintaining quality of care? The authors argue that innovation driven by rigorous competition is the key to successful reform. A lasting cure for health care in the United States should include four basic elements: corrected incentives to spur productive competition, universal insurance to secure economic efficiency, relevant information to ensure meaningful choice, and innovation to guarantee dynamic improvement. In this issue's Perspectives section, eleven experts examine the current state of the health care system and offer their views on the shape that reform should take. Some excerpts: "On the road to innovation, let us not forget to develop the tools that allow physicians, payers, and patients to make better decisions." I. Steven Udvarhelyi; "Health care is not a product or service that can be standardized, packaged, marketed, or adequately judged by consumers according to quality and price." Arnold S. Relman; "Just as antitrust laws are the wise restraints that make competition free in other sectors of the economy, so the right kind of managed competition can work well in health care." Edward M. Kennedy "Biomedical research should be considered primarily an investment in the national economic well-being with additional humanitarian benefits." Elizabeth Marincola.  相似文献   
44.
In 1972, the US and Canada committed to restore the chemical, physical, and biological integrity of the Great Lakes Ecosystem under the first Great Lakes Water Quality Agreement. During subsequent amendments, part of the St. Lawrence River at Massena NY, and segments of three tributaries, were designated as one Area of Concern (AOC) due to various beneficial use impairments (BUIs). Plankton beneficial use was designated impaired within this AOC because phytoplankton and zooplankton population data were unavailable or needed “further assessment”. Contaminated sediments from industrial waste disposal have been largely remediated, thus, the plankton BUI may currently be obsolete. The St. Lawrence River at Massena AOC remedial action plan established two criteria which may be used to assess the plankton BUI; the second states that, “in the absence of community structure data, plankton bioassays confirm no toxicity impact in ambient waters”. This study was implemented during 2011 to determine whether this criterion was achieved. Acute toxicity and chronic toxicity of local waters were quantified seasonally using standardized bioassays with green alga Selenastrum capricornutum and water flea Ceriodaphnia dubia to test the hypothesis that waters from sites within the AOC were no more toxic than were waters from adjacent reference sites. The results of univariate and multivariate analyses confirm that ambient waters from most AOC sites (and seasons) were not toxic to both species. Assuming both test species represent natural plankton assemblages, the quality of surface waters throughout most of this AOC should not seriously impair the health of resident plankton communities.  相似文献   
45.
While historians have for a long time recognized the importance of the First World War to the general flow of history, business economists do not fully appreciate the impact of the war on commercial relationships. The First World War transformed the political, economic, and social context, in which business was done, forcing companies to develop new strategies and activities, some of which were almost unimaginable before August 1914. This article focuses on one aspect of doing business: foreign exchange management. It argues that Schering AG and its parent, like many German companies after the First World War, were obliged to refocus their activities around their foreign exchange exposures and that the management of foreign exchange issues contributed to a much tighter relationship between businesses, government, and business associations than had existed before the war and for which some aspects of Germany's system of corporate control were not well adapted to handle.  相似文献   
46.
47.
This study examines the association between activity-based costing and manufacturing performance. Results using a cross-sectional sample of manufacturing plants indicates that extensive ABC use is associated with higher quality levels and greater improvements in cycle time and quality, and is indirectly associated with manufacturing cost reductions through quality and cycle time improvements. However, on average, extensive ABC use has no significant association with return on assets. Instead, we find weak evidence that the association between ABC and accounting profitability is contingent on the plant's operational characteristics.  相似文献   
48.
Incentive Fees and Mutual Funds   总被引:10,自引:1,他引:10  
This paper examines the effect of incentive fees on the behavior of mutual fund managers. Funds with incentive fees exhibit positive stock selection ability, but a beta less than one results in funds not earning positive fees. From an investor's perspective, positive alphas plus lower expense ratios make incentive-fee funds attractive. However, incentive-fee funds take on more risk than non-incentive-fee funds, and they increase risk after a period of poor performance. Incentive fees are useful marketing tools, since more new cash flows go into incentive-fee funds than into non-incentive-fee funds, ceteris paribus.  相似文献   
49.
This study sought to measure the economic consequences of reduced expenditure on specific sections of the UK National Measurement System (NMS), part of the state-funded technological infrastructure. A method was developed which can be adapted to any publicly or privately financed R&D of which the benefits and cost-effectiveness are unclear or contested.
The recent interactions between the NMS and industry were investigated empirically. Five mechanisms were found to account for the majority of instances of successful value creation. Several case studies of each mechanism were collected, illustrating their existence beyond reasonable doubt.
Each of the cut projects would have been expected to have encouraged growth and profitability in identified sectors of the economy through one or more of these five mechanisms. The effects of the cuts were modelled over 30 years. Compared to the costs of the cut projects projected over the same period, the benefits to the economy were predicted to exceed the costs.  相似文献   
50.
The last thirty years have witnessed the appearance and rapid expansion of Islamic banking both inside and outside the Islamic world. Islamic banks provide financial products that do not violate Sharia , the Islamic law of human conduct. The Islamic principles upon which the banks claim to operate give an important role to social issues. Applying these principles, we develop a benchmark set of social disclosures appropriate to Islamic banks. These are then compared, using a disclosure index approach, the actual social disclosures contained in the annual reports of twenty-nine Islamic banks (located in sixteen countries) to this benchmark. In addition, content analysis is undertaken to measure the volume of social disclosures. Our analysis suggests that social reporting by Islamic banks falls significantly short of our expectations. The results of the analysis also suggest that banks required to pay the Islamic religious tax Zakah provide more social disclosures than banks not subject to Zakah .  相似文献   
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