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排序方式: 共有189条查询结果,搜索用时 578 毫秒
41.
技术专家办企业的农业生物技术推广模式探讨 总被引:1,自引:0,他引:1
技术推广模式是关系到科技成果转化和相关产业稳定发展的重要因素.在对我国原有四种农业技术推广模式分析的基础上,构建和完善了技术专家领衔办企业的农业生物技术推广模式及运行机制,并对这种模式的未来发展定位问题进行了探讨. 相似文献
42.
Evaluating the possible benefits of the introduction of genetically modified (GM) crops must address the issue of consumer resistance as well as the complex regulation that has ensued. In the European Union (EU), this regulation envisions the co‐existence of GM food with conventional and quality‐enhanced products, mandates the labelling and traceability of GM products and allows only a stringent adventitious presence of GM content in other products. All these elements are brought together within a partial equilibrium model of the EU agricultural food sector. The model comprises conventional, GM and organic food. Demand is modelled in a novel fashion, whereby organic and conventional products are treated as horizontally differentiated but GM products are vertically differentiated (weakly inferior) relative to conventional ones. Supply accounts explicitly for the land constraint at the sector level and for the need for additional resources to produce organic food. Model calibration and simulation allow insights into the qualitative and quantitative effects of the large‐scale introduction of GM products in the EU market. We find that the introduction of GM food reduces overall EU welfare, mostly because of the associated need for costly segregation of non‐GM products, but the producers of quality‐enhanced products actually benefit. 相似文献
43.
Meat retailers express demand for a more uniform product, and technical innovations are allowing an increasingly uniform supply. Packers can promote uniformity through pre-slaughter sorting, or earlier through contracts. Emphasizing effort on the packing line, we develop a model whereby packers gain from carcass handling efficiencies when animal uniformity increases. Whether optimally regulated or not, equilibrium food safety declines with increased uniformity. A line speed regulation can increase welfare in the presence of food safety externalities by reducing the opportunity cost of allocating effort toward promoting food safety. The regulation also reduces packer demand for more uniform animals. 相似文献
44.
45.
Jeremy D. Foltz Kwansoo Kim Bradford Barham 《American journal of agricultural economics》2003,85(1):187-197
This article examines the factors that account for agricultural biotechnology patenting success among universities using a dynamic count data model. It builds a theoretical and econometric model to capture the inherently dynamic and nonlinear process of technological innovation, wherein a feedback mechanism from previous success partially determines current patent counts. The econometric estimates reveal the importance to agricultural biotechnology patent production of land grant infrastructure, quality faculty, patent-oriented technology transfer offices, as well as dynamic feedback effects. 相似文献
46.
Ayala Wineman Timothy Njagi C. Leigh Anderson Travis W. Reynolds Didier Yélognissè Alia Priscilla Wainaina Eric Njue Pierre Biscaye Miltone W. Ayieko 《Journal of Agricultural Economics》2020,71(3):719-741
Studies of improved seed adoption in developing countries are almost always based on household surveys and are premised on the assumption that farmers can accurately self-report their use of improved seed varieties. However, recent studies suggest that farmers’ reports of seed varieties planted, or even whether the seed is local or improved, are sometimes inconsistent with the DNA fingerprinting results of those crops. We use household survey data from Tanzania to test the alignment between farmer-reported and DNA-identified maize seed types planted. In the sample, 70% of maize seed observations are correctly reported as local or improved, while 16% are type I errors (falsely reported as improved) and 14% are type II errors (falsely reported as local). Type I errors are more likely to have been sourced from other farmers, rather than formal channels. An analysis of input use, including seed, fertiliser, and labour allocations, reveals that farmers tend to treat improved maize differently, depending on whether they correctly perceive it as improved. This suggests that errors in farmers’ seed type awareness may translate into suboptimal management practices. The average yield of seed that is correctly identified as improved is almost 700 kg per hectare greater than that of type I errors. This indicates that investments in farmers’ access to information, seed labelling, and seed system oversight are needed to complement investments in seed variety development. 相似文献
47.
China was the first developing country to introduce Bt cotton on a large scale. This paper provides an indepth economic analysis of Bt cotton production by small-scale farmers in China. Data were collected in 2002 in Linqing County, in Shandong Province and comprised a season-long cotton production monitoring with 150 farmers and complementary household interviews. For quality assessment, the Bt toxin concentration of the various Bt varieties used by the farmers was determined for each plot. All farmers were growing insect resistant Bt cotton varieties. Yet, they sprayed high amounts of chemical insecticides, out of which 40% were extremely or highly hazardous. The paper reviews methodological issues inherent to impact assessment of crop biotechnology and identifies market and institutional failure as possible reasons for continued high pesticide use. Using the damage function methodology the coefficients for both damage control inputs, i.e., Bt varieties (measured as toxin concentration), and insecticide quantity were not significantly different from zero. Results show that absence of enabling institutions and lack of farmer knowledge can considerably limit the benefits of Bt cotton for small-scale farmers. The paper points out the importance to include the institutional conditions in the evaluation of agricultural biotechnology in developing countries. 相似文献
48.
Despite widespread awareness that scientific record and grant funding reinforce one another, empirical models of scientific production normally consider laboratory inputs to be exogenous. The present article employs a cross-section of academic bioscientists to examine the mutual relationship between research output and financial support. Information's nonrival character is such that scientific output and funding success cannot be expressed in strictly supply-and-demand terms. We find the typical bioscience laboratory to operate in a range of decreasing returns to scale and to over-invest in laboratory equipment and materials. Publication and funding success strongly reinforce one another, explaining the right-skewed success distributions often observed in science. 相似文献
49.
Andrei Sobolevsky GianCarlo Moschini Harvey Lapan 《American journal of agricultural economics》2005,87(3):621-644
A partial equilibrium four-region world trade model for the soybean complex is developed in which Roundup Ready (RR) products are weakly inferior substitutes to conventional ones, RR seeds are priced at a premium, and costly segregation is necessary to separate conventional and biotech products. Solution of the calibrated model illustrates how incomplete adoption of RR technology arises in equilibrium. The United States, Argentina, Brazil, and the Rest of the World (ROW) all gain from the introduction of RR soybeans, although some groups may lose. The impacts of RR production or import bans by the ROW or Brazil are analyzed. U.S. price support helps U.S. farmers, despite hurting the United States and has the potential to improve world efficiency. 相似文献
50.
《Food Policy》2014
Since the late 1980s, technological advances and policy reforms have created new opportunities for private-sector investment in India’s seed and agricultural biotechnology industries. These changes have had a significant impact on cotton yields and output in India, but less so for rice and wheat—the country’s main cereal staples—for which yield growth rates are tending toward stagnation. This analysis examines the structures of these industries, their potential effects on competition and innovation, and the policies that may improve both industry performance and the delivery of new productivity-enhancing technologies to India’s cereal production systems. Our findings suggest that more substantive policy reforms are needed to encourage further innovation, reduce regulatory uncertainty, and encourage firm- and industry-level growth, while continued public spending on agricultural research is needed to support technological change. 相似文献