30 resultados para Mamonova, Tatyana , 1943-


Relevância:

10.00% 10.00%

Publicador:

Relevância:

10.00% 10.00%

Publicador:

Relevância:

10.00% 10.00%

Publicador:

Relevância:

10.00% 10.00%

Publicador:

Relevância:

10.00% 10.00%

Publicador:

Relevância:

10.00% 10.00%

Publicador:

Resumo:

土壤有机质在养分循环、土壤理化性质等方面具有重要作用 ,是陆地生态系统重要的碳库 ,对全球碳素循环的平衡起着重要作用 .本文详细阐述了杉木林地土壤有机质的性质与组成 ,杉木连栽对土壤有机质含量、腐殖质结合形态的影响以及林分发育过程中土壤有机质的变化 ,炼山、整地、施肥等经营活动对杉木林地土壤有机质的影响 .杉木纯林有机质含量和质量均低于混交林 ,且随栽植代数的增加有机质含量和质量呈下降趋势 ,林地土壤肥力下降 .最后提出应加强对土壤有机质周转模型、有机质组分 ,尤其是活性有机质以及有机质与全球碳循环关系的研究 .

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The core-shell structured YNbO4:Eu3+/Tb3+@SiO2 particles were realized by coating the YNbO4:Etr(3+)/Tb3+ phosphors onto the surface of spherical silica via a sol-gel process. The obtained materials were characterized by means of X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Fourier transform IR spectroscopy (FT-IR), photoluminescence (PL) spectra, and cathodoluminescence (CL) spectra.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A new kind of aromatic diaminospirodilactone, i.e. 6,6'-diamino-3, 3'-spirobiphthalide, was synthesized through multistep reactions from p-nitrotoulene and paraformaldehyde, It was: found that dinitrospirolactone could be synthesized directly in the acid system through oxidation reaction with a high yield, The increase of solvent polarity leads to an increase of reduction yield of dinitrolactone. The resulting intermediates 6, 6'-dihydroxylamino-3, 3'-spirobiphthalide and 6-amino-6'-hydroxylanimo-3, 3'-spirobiphthalide were steady aromatic hydroxylamine. The structures of 6, 6'-diamino-3, 3'-spirobiphthalide and its intermediates were confirmed by H-1 NMR, C-13 NMR, MS, IR and elemental analyses.

Relevância:

10.00% 10.00%

Publicador:

Relevância:

10.00% 10.00%

Publicador:

Relevância:

10.00% 10.00%

Publicador:

Resumo:

大兴安岭中段林西地区二叠纪大石寨组下部的细碧角斑岩建造记录了大石寨裂陷槽早期的发育历史,因而对其成因和构造环境的研究具有一定的意义。本文在详细地野外工作基础上,对二叠系大石组的细碧岩进行了较为系统的岩石学、元素地球化学及同位素地球化学研究。结果表明,细碧岩的岩石类型为玄武岩、玄武安山岩、安山岩、橄榄组安岩和粗安岩(或歪长粗面岩),属于拉斑玄武岩岩石系列;细碧岩的主量元素质量分数及变化范围类型似于N-MORB玄武岩;与正常洋中脊玄武岩相比较,细碧岩的LILE元素明显富集,HFSE元素的质量分数与大洋中脊玄武岩(N-MORB)相接近,Nb,Ta明显亏损;细碧岩的稀土元素分配模式具平坦型;(^87Sr/^86Sr)t为0.7013-0.7056。细碧岩形成于大石寨裂陷槽早期裂陷阶段弧后盆地局部扩张的构造环境;细碧岩是由拉斑玄武质岩浆在上升过程中热卤水的严重混染后喷出地表结晶而形成的。