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不同栽杉代数29年生杉木林净生产力及营养元素生物循环的研究 被引量:32
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作者 杨玉盛 邱仁辉 +2 位作者 何宗明 俞新妥 黄宝龙 《林业科学》 EI CAS CSCD 北大核心 1998年第6期3-11,共9页
对南平溪后29年生杉木林不同连栽代数林分生物量、净生产力及营养元素生物循环的研究结果表明:随连栽代数增加,林分总生物量下降,林分净生长量及乔木层净生长量占林分净生长量比例均有明显降低,生态系统中营养元素贮量减少,乔木... 对南平溪后29年生杉木林不同连栽代数林分生物量、净生产力及营养元素生物循环的研究结果表明:随连栽代数增加,林分总生物量下降,林分净生长量及乔木层净生长量占林分净生长量比例均有明显降低,生态系统中营养元素贮量减少,乔木层营养元素吸收量、存留量和归还量均下降,但林下植被层营养元素吸收量、存留量和归还量则明显增加,林分的营养元素吸收量、存留量和归还量却增大。不同代数杉木林营养元素总的循环速率为2代(0493)>1代(0460)>3代(0439)。 展开更多
关键词 杉木 连载代数 净生产力 营养元素 生产循环
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The varieties of Heisenberg vertex operator algebras 被引量:3
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作者 CHU Yan Jun LIN Zong Zhu 《Science China Mathematics》 SCIE CSCD 2017年第3期379-400,共22页
For a vertex operator algebra V with conformal vector w, we consider a class of vertex operator subalgebras and their conformal vectors. They are called semi-conformal vertex operator subalgebras and semi- conformal v... For a vertex operator algebra V with conformal vector w, we consider a class of vertex operator subalgebras and their conformal vectors. They are called semi-conformal vertex operator subalgebras and semi- conformal vectors of (V, w), respectively, and were used to study duality theory of vertex operator algebras via coset constructions. Using these objects attached to (V,w), we shall understand the structure of the vertex operator algebra (V,w). At first, we define the set Sc(V,w) of semi-conformal vectors of V, then we prove that Sc(V,w) is an aiYine algebraic variety with a partial ordering and an involution map. Corresponding to each semi-conformal vector, there is a unique maximal semi-conformal vertex operator subalgebra containing it. The properties of these subalgebras are invariants of vertex operator algebras. As an example, we describe the corresponding varieties of semi-conformal vectors for Heisenberg vertex operator algebras. As an application, we give two characterizations of Heisenberg vertex operator algebras using the properties of these varieties. 展开更多
关键词 vertex operator algebra semi-conformal vector VARIETY
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