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中国玉米生产-消费体系养分流动分析 被引量:6
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作者 李建辉 马林 +3 位作者 王激清 王方浩 马文奇 张福锁 《自然资源学报》 CSCD 北大核心 2007年第3期455-462,共8页
采用物质流和养分流相结合的分析方法,沿玉米生产的肥料投入到玉米消费过程,研究氮、磷养分流动;以2004年为例,分析了中国玉米生产消费过程中氮、磷养分流动特点和资源的利用效率。2004年玉米生产投入化肥氮(N)549.6×104t、磷(P2O5... 采用物质流和养分流相结合的分析方法,沿玉米生产的肥料投入到玉米消费过程,研究氮、磷养分流动;以2004年为例,分析了中国玉米生产消费过程中氮、磷养分流动特点和资源的利用效率。2004年玉米生产投入化肥氮(N)549.6×104t、磷(P2O5)211.2×104t;共收获养分氮(N)342.9×104t、磷(P2O5)139.4×104t,其中75%的氮和68%的磷被利用,最终进入家庭的氮占22.3%,磷为15.0%;秸秆中氮的还田率只有47%,磷的较高,在80%左右,可见秸秆还田是归还土壤磷的有效措施。玉米生产要消耗大量的资源,2004年生产1t玉米养分,消耗的化肥氮、磷养分相当于煤5.2t、磷矿资源12.1t。因此,优化玉米整个生产与消费体系中养分的流动,对于提高养分资源利用效率和减少资源浪费具有重要作用。 展开更多
关键词 养分资源管理 效率 养分流 玉米 生产-消费体系
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Dilemmas and Obstacles: Multilateral Energy Cooperation Among BRICS Countries
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作者 Su-yuan Sun 《Fudan Journal of the Humanities and Social Sciences》 2014年第3期395-410,共16页
Multilateral energy cooperation among BRICS countries remains largely at the stage of initiatives with few substantial actions that have been taken so far. Three main reasons can account for it. One is a contending co... Multilateral energy cooperation among BRICS countries remains largely at the stage of initiatives with few substantial actions that have been taken so far. Three main reasons can account for it. One is a contending concern of energy security that constrains energy cooperation between energy producing countries and energy consuming countries. The second is energy diplomacy with self-help logic as the main principle, which discourages BRICS countries from taking collective actions to secure their energy security. The third one is the international energy system that conditions BRICS countries to participate in the international energy cooperation. As a result, multilateral energy cooperation is of secondary importance in the agenda of BRICS countries, and the degree of their involvement in global energy cooperation is relatively low. 展开更多
关键词 BRICS Multilateral energy cooperation Energy security Energy diplomacy
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