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11.
Jane Kabubo-Mariara 《Ecological Economics》2007,64(1):25-35
Land conservation technologies used by farmers are known to play an important role in improving farm incomes and household welfare in the long run. For this reason substantial investments have been made in research to improve agricultural technologies in various parts of the world, from the development of new crop varieties to new practices of land management. This paper explores the impact of land rights among other factors on adoption of soil and water conservation practices. The study further tests for Boserup's hypothesis (correlation between population density, land conservation and property rights) using panel survey data collected from farming households. The key findings of the paper are that property right regimes and population density affect both the decision to conserve land as well as the type of conservation practices used by farmers. The results further suggest a positive correlation between land tenure security and population density, thus supporting Boserup's hypothesis. The findings call for pursuit of both short-term and long-term policy measures that offer incentives for land conservation through government initiatives and participation of local communities. 相似文献
12.
Kenshi Itaoka Aya Saito Alan Krupnick Wiktor Adamowicz Taketoshi Taniguchi 《Environmental and Resource Economics》2006,33(3):371-398
The objective of this study is to estimate willingness to pay (WTP) for the reduction of mortality risks caused by fossil
fuel (natural gas, coal and oil) versus nuclear electric power generation systems and to examine the influence of risk characteristics
involved with electric power generation on WTP. A choice experiment was conducted to achieve these objectives. The attributes
for nuclear risks in the experiment included the probability of disasters and the expected losses if a disaster occurs. We
find evidence of (i) a baseline effect (where WTP is sensitive to hypothetical versus actual baseline expected mortality);
(ii) a ‘labeling effect,’ where, surprisingly, the term ‘nuclear’ has no effect on WTP, but the term ‘fossil-fueled power
generation’ results in lower WTP; and (iii) disaster aversion, meaning that people focus on the conditional loss from a nuclear
disaster, not the probability. We also find that the WTP for reducing deaths from a nuclear disaster is about 60 times the
WTP for routine reducing fossil-fuel generation-related deaths. 相似文献
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14.
本文详细分析了三相内反馈磁放大器式硅弧焊整流器的控制特性,给出了各铁心的磁通密度变化规律及输出电压 U_o 与控制电流 I_K 之间的数学表达式。对确定内反馈磁放大器式硅弧焊整流器一些参数有一定的指导意义。 相似文献
15.
We propose a new procedure to estimate the loss given default (LGD) distribution. Owing to the complicated shape of the LGD distribution, using a smooth density function as a driver to estimate it may result in a decline in model fit. To overcome this problem, we first apply the logistic regression to estimate the LGD cumulative distribution function. Then, we convert the result into the LGD distribution estimate. To implement the newly proposed estimation procedure, we collect a sample of 5269 defaulted debts from Moody’s Default and Recovery Database. A performance study is performed using 2000 pairs of in-sample and out-of-sample data-sets with different sizes that are randomly selected from the entire sample. Our results show that the newly proposed procedure has better and more robust performance than its alternatives, in the sense of yielding more accurate in-sample and out-of-sample LGD distribution estimates. Thus, it is useful for studying the LGD distribution. 相似文献
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城市对外交通中,铁路是发展较早的交通运输方式。本文以新疆的铁路交通网络为依据,以道路密度为指标,利用Arc GIS的叠加分析和空间分析功能,研究新疆铁路交通网络的空间分异,并分析新疆各区域人口、生产总值差异与铁路密度差异之间的相互关系。结果表明:(1)新疆铁路密度差异显著,大体呈现"南北低中部高"的趋势;(2)新疆各地区铁路密度与人口分布、生产总值高度正相关。 相似文献
18.
This paper examines the cost structures of the leading integrated air cargo carriers, FedEx Express and UPS Airlines. A total cost model is estimated for the two carriers using quarterly data on domestic operations and costs over a nine-year period (2003–2011). The estimated model indicates that the integrated industry exhibits increasing returns to traffic density and constant returns to scale. Accounting for carrier-specific differences in cost structure and network size, FedEx Express is found to be more cost-efficient than UPS Airlines. Looking at the carriers individually, UPS Airlines exhibits substantial economies of traffic density and constant returns to scale while FedEx Express' cost structure is characterized by weak economies of density and constant returns to scale. The combined effect of returns to density and returns to scale on the cost structures of integrated carriers is captured by economies of size. Both FedEx Express and UPS Airlines exhibit economies of size, indicating that carriers in the integrated industry can be more cost efficient by making appropriate adjustments to their network size as their output grows. Moreover, the relative cost-efficiencies of the carriers are reversed when their network-size differences are not controlled. 相似文献
19.
The paradox of development vs. protection and conservation of the coasts highlights the need to determine if tourism and conservation can be compatible rather than opposite activities. We analyzed the spatial and temporal changes in vegetation cover, composition and diversity in three beaches located in the state of Veracruz (Mexico) with different levels of tourism activity (Natural, Trailer Park and Hotels). We calculated tourist density and evaluated vegetation cover, species richness and diversity and analyzed the changes before and after three holiday seasons (winter, spring and summer). The Natural site had the highest vegetation cover (42.8 m2), species richness (14) and diversity (1.50), and Trailer Park the lowest (4.9 m2, 8 species, and 0.897 respectively). The BACI (Before-After-Control-Design) analysis showed no significant differences before and after the holiday seasons. Our results show how low and medium density tourism can be compatible with the protection of beach and coastal dune vegetation. 相似文献
20.
A special feature of China’s housing market is land use rights in the form of land leasehold contracts granted by the government. We consider an equilibrium model in which a representative developer may choose to redevelop existing centrally located housing or to develop new housing at the periphery of the city. We show that as the city grows, the land leasehold system results in the city center being developed less intensely and more land being used on the outskirts of the city when compared to a fee simple environment. Thus, cities in China are likely to be relatively more spread out, with city centers relatively older than would be the case with “fee simple” ownership. Our model suggests that excess residential land use is about 6 percent. In addition, compared with the ownership case, housing supply will grow more quickly in the near future, but more slowly later on during the transition of the Chinese economy. Parallel to the supply growth pattern, equilibrium price grows relative slowly in the near future, but more quickly later on. While we focus on residential uses, we believe our model can be applied to other land uses. 相似文献