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德国波恩大学农业生产科学专业阶段教学特点 被引量:2
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作者 康贝贝 《高等农业教育》 2000年第11期91-95,共5页
关键词 德国 高校 教学特点 阶段教育 农业生产科学专业
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德国波恩大学农业生产科学基础阶段教学计划分析
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作者 张艳 康贝贝 《高等农业教育》 2000年第7期89-92,共4页
关键词 德国 波恩大学 农业生产科学 基础阶段教学 教学计划 教学体制 中国 比较研究
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我国粮食生产阶段中农业科技生产效率问题研究 被引量:2
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作者 周向阳 《中国食物与营养》 2015年第12期19-23,共5页
粮食产量每增加1亿t为分类标准,将我国1949年以来的粮食生产历程划分为五个阶段。首先梳理每个生产阶段粮食产量、播种面积和单位面积产量的变化特征,其次回顾了农业科技事业在每个阶段的发展情况,最后采用数据包络方法 (DEA)测算了从1... 粮食产量每增加1亿t为分类标准,将我国1949年以来的粮食生产历程划分为五个阶段。首先梳理每个生产阶段粮食产量、播种面积和单位面积产量的变化特征,其次回顾了农业科技事业在每个阶段的发展情况,最后采用数据包络方法 (DEA)测算了从1989—2013年的农业科学技术生产率。 展开更多
关键词 粮食生产 农业科技 数据包络方法 农业科学技术生产
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葫芦河流域间套复种方式的初步评价
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作者 谢成君 何建栋 +1 位作者 彭桃芝 黄占刚 《农业科学研究》 1993年第4期41-45,共5页
本文根据1988年以来进行的九种间套复种方式试验积累的资料,运用技术经济评价原则和线性隶属函数综合评价模型,筛选出西吉县经济、生态、社会效益较高的立体复合种植方式——“小麦、玉米、绿肥;玉米、蚕豆、绿肥和玉米、胡麻、绿肥”... 本文根据1988年以来进行的九种间套复种方式试验积累的资料,运用技术经济评价原则和线性隶属函数综合评价模型,筛选出西吉县经济、生态、社会效益较高的立体复合种植方式——“小麦、玉米、绿肥;玉米、蚕豆、绿肥和玉米、胡麻、绿肥”三个优化组合,为本地区农业生产种植方式决策提供科学依据。 展开更多
关键词 立体复合种植方式 线性隶属函数评价 农业生产科学决策
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Public Perceptions of Cryosphere Change and the Selection of Adaptation Measures in the rmqi River Basin 被引量:1
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作者 Maozhi Deng Hongguang Zhang +1 位作者 Weiyi Mao Yingwei Wang 《Advances in Climate Change Research》 SCIE 2011年第3期149-158,共10页
This study focuses on the characters of public perceptions on climate and cryosphere change,which are based on a questionnaire survey in the(U|¨)r(u|¨)mqi River Basin.In comparison with scientific observatio... This study focuses on the characters of public perceptions on climate and cryosphere change,which are based on a questionnaire survey in the(U|¨)r(u|¨)mqi River Basin.In comparison with scientific observation results of climate and cryosphere change,this paper analyzes the possible impact of the change on water resources and agriculture production in the area.Perceptions of most respondents on climate and cryosphere changes confirm the main objective facts.For the selection of adaptation measures addressing the shortage of water resource,the results are as follows:most people preferred to choose the measures like "policy change" and "basic facility construction" which are mostly implemented by the government and the policy-making department;some people showed more preference to the measures of avoiding unfavorable natural environment,such as finding job in or migrating to other places.The urgency of personal participation in the adaptation measures is still inadequate.Some adaptation measures should be implemented in line with local conditions and require the organic combination of "resource-development" with "water-saving". 展开更多
关键词 climate change cryosphere change public perception adaptation measures questionnaire survey
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Combustion Irreversibilities: Numerical Simulation and Analysis
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作者 Valter Silva Abel Rouboa 《Journal of Thermal Science》 SCIE EI CAS CSCD 2012年第4期377-383,共7页
An exergy analysis was performed considering the combustion of methane and agro-industrial residues produced in Portugal (forest residues and vines pruning). Regarding that the irreversibilities of a thermodynamic pro... An exergy analysis was performed considering the combustion of methane and agro-industrial residues produced in Portugal (forest residues and vines pruning). Regarding that the irreversibilities of a thermodynamic process are path dependent, the combustion process was considering as resulting from different hypothetical paths each one characterized by four main sub-processes: reactant mixing, fuel oxidation, internal thermal energy exchange (heat transfer), and product mixing. The exergetic efficiency was computed using a zero dimensional model developed by using a Visual Basic home code. It was concluded that the exergy losses were mainly due to the internal thermal energy exchange sub-process. The exergy losses from this sub-process are higher when the reactants are preheated up to the ignition temperature without previous fuel oxidation. On the other hand, the global exergy destruction can be minored increasing the pressure, the reactants temperature and the oxygen content on the oxidant stream. This methodology allows the identification of the phenomena and processes that have larger exergy losses, the understanding of why these losses occur and how the exergy changes with the parameters associated to each system which is crucial to implement the syngas combustion from biomass products as a competitive technology. 展开更多
关键词 EXERGY Combustion paths Combustion sub-processes Exergetic efficiency Visual Basic SYNGAS
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