Mountainous areas exhibit highly variable decomposition rates as a result of strong local differences in climate and vegetation type. This paper describes the effect of these factors on two major determinants of the l...Mountainous areas exhibit highly variable decomposition rates as a result of strong local differences in climate and vegetation type. This paper describes the effect of these factors on two major determinants of the local carbon cycle: litter decomposition and carbon stabilization. In order to adequately reflect local heterogeneity, we have sampled 12 typical plant communities of the Russian Caucasus. In order to minimize confounding effects and encourage comparative studies, we have adapted the widely used tea bag index(TBI) that is typically used in areas with low decomposition. By incubating standardized tea litter for a year, we investigated whether(1) initial litter decomposition rate(k) is negatively correlated with litter stabilization(S) and(2) whether k or S exhibit correlations with altitude and other environmental conditions. Our results show that S and k are not correlated. Altitude, p H, and water content significantly influenced the stabilization factor S, while soil-freezing had no influence. In contrast, none of these factors predicted the decomposition rate k. Based on our data, we argue that collection of decomposition rates alone, as is now common practice, is not sufficient to understand carbon input to soils and can potentially lead to misleading results. Our data on community-specific decomposition and stabilization rates further constrain estimates of litter accumulation in subalpine communities and the potential effects of climate change.展开更多
介绍了由有机半导体材料酞菁铜制作的具有 Au/CuPc/Al/CuPc/Au 三明治结构的肖特基型栅极有机静电感应三极管。根据对该三极管测试,采用适当的数学工具,对其参数进行计算。通过 I - V 方程的拟合,对其动作特性进行了研究。通过对小信号...介绍了由有机半导体材料酞菁铜制作的具有 Au/CuPc/Al/CuPc/Au 三明治结构的肖特基型栅极有机静电感应三极管。根据对该三极管测试,采用适当的数学工具,对其参数进行计算。通过 I - V 方程的拟合,对其动作特性进行了研究。通过对小信号等效电路模型的仿真计算,得出其截止频率,并提出了改善其动作特性的途径。展开更多
Nanocomposites were prepared by a simple technique of emulsion polymerization using VC monomer and Na + montmorillonite. The nano structure of the composites was studied with the aid of X ray diffraction and t ransmis...Nanocomposites were prepared by a simple technique of emulsion polymerization using VC monomer and Na + montmorillonite. The nano structure of the composites was studied with the aid of X ray diffraction and t ransmission electron microscopy,and the mechanical and thermal properties of th e composites were also tested. The results showed that the silicate layers were delam inated or partially exfoliated in the PVC matrix. The impact strength of the mat erial with 2 1% MMT was almost two times as high as that of pure PVC, while the tensi le strength decreased little. However, the mechanical strength of the composites began to decrease with further increasing the amount of MMT. The TGA resul ts showed that the temperature,at which a 50% weight loss of the composites occurred,was higher than that of pure PVC. The vicat softening temperatures of composites were enhanced with increasing MMT content.展开更多
基金supported by Russian Science Foundation(RSF),grant№16-14-10208
文摘Mountainous areas exhibit highly variable decomposition rates as a result of strong local differences in climate and vegetation type. This paper describes the effect of these factors on two major determinants of the local carbon cycle: litter decomposition and carbon stabilization. In order to adequately reflect local heterogeneity, we have sampled 12 typical plant communities of the Russian Caucasus. In order to minimize confounding effects and encourage comparative studies, we have adapted the widely used tea bag index(TBI) that is typically used in areas with low decomposition. By incubating standardized tea litter for a year, we investigated whether(1) initial litter decomposition rate(k) is negatively correlated with litter stabilization(S) and(2) whether k or S exhibit correlations with altitude and other environmental conditions. Our results show that S and k are not correlated. Altitude, p H, and water content significantly influenced the stabilization factor S, while soil-freezing had no influence. In contrast, none of these factors predicted the decomposition rate k. Based on our data, we argue that collection of decomposition rates alone, as is now common practice, is not sufficient to understand carbon input to soils and can potentially lead to misleading results. Our data on community-specific decomposition and stabilization rates further constrain estimates of litter accumulation in subalpine communities and the potential effects of climate change.
文摘介绍了由有机半导体材料酞菁铜制作的具有 Au/CuPc/Al/CuPc/Au 三明治结构的肖特基型栅极有机静电感应三极管。根据对该三极管测试,采用适当的数学工具,对其参数进行计算。通过 I - V 方程的拟合,对其动作特性进行了研究。通过对小信号等效电路模型的仿真计算,得出其截止频率,并提出了改善其动作特性的途径。
文摘Nanocomposites were prepared by a simple technique of emulsion polymerization using VC monomer and Na + montmorillonite. The nano structure of the composites was studied with the aid of X ray diffraction and t ransmission electron microscopy,and the mechanical and thermal properties of th e composites were also tested. The results showed that the silicate layers were delam inated or partially exfoliated in the PVC matrix. The impact strength of the mat erial with 2 1% MMT was almost two times as high as that of pure PVC, while the tensi le strength decreased little. However, the mechanical strength of the composites began to decrease with further increasing the amount of MMT. The TGA resul ts showed that the temperature,at which a 50% weight loss of the composites occurred,was higher than that of pure PVC. The vicat softening temperatures of composites were enhanced with increasing MMT content.
