Distribution of plants differing in attitude toward thermal conditions in communities of the timberline ecotone on Mount Iremel’, the Southern Urals

Specific features in the distribution of plant species differing in their attitude toward thermal conditions have been studied in communities of the present-day timberline ecotone on Mount Iremel’ in the Southern Urals. It has been shown that the distribution of such species is characterized by significant spatial nonuniformity. Elevation above sea level, local conditions in habitats located at the same altitudinal level, and specific features of mountain slopes account for 13–84, 5–30, and 0.4–14% of the total variance of test parameters, respectively. The abundance of plants changes nonlinearly along the altitudinal gradient, whereas changes in the species diversity of different plant groups have an almost linear pattern. Marked differences between plant communities with respect to the proportions of species differently responding to changes in thermal conditions have been revealed on all slopes in the upper part of the timberline ecotone, upon transition from the slopes proper to the plateau-like areas of intermontane depressions.     

Changes in the sex structure of pine populations related to temperature anomalies

The results of ten-year observations on fluctuations in the sex of individual trees and the sex structure of tree stands in two insular pine forests in the south of Central Siberia are presented. It is noted that the ratio of sex types of pine trees has markedly changed since 1998–1999. Significant correlations between the sex structure of stands and anomalies of the annual average air temperature have been recorded since the early 1990s. The male generative sphere of pine has changed to the greatest extent. Periodicity and delay in the change of shoot sexualization in response to changes in temperature are discussed.     

Seasonal changes in the spatial distribution of cellulolytic activity of soil microflora under conditions of atmospheric pollution

Spatial variation in the cellulolytic activity of the soil microflora during the growing season (from May to September) has been studied in spruce-fir forests exposed to emissions from the Middle Ural Copper-Smelting Plant. It has been shown that the average rate of decomposition of pure cellulose in polluted areas is significantly reduced, with its spatial variation being markedly increased. The spatial pattern of cellulolytic activity remains stable during the growing season, and the integrated parameters of frequency distributions in zones with different pollution levels change with time in the same direction.     

土地形成的社会动力学——德国大型“水厂”的经验(论文摘编)

The contribution redefines the concept of“terra-forming”and the basically technical term“waterworks”froma sociological interpretation of metabolism:since human reproduction emancipatedfrom mereparticipation fromnature,it became,at least,a systematic transformation of nature.Irrigation and drain-age became the twin brothers of agriculture and mining,the most i mportant modifiers of both metabolismand natureitself.Fromthe early“hydraulic”toward modern“industrial”societies,the systemic co…     

Dynamics of species and species complexes as a field of research in historical ecology

Specific features of research on the dynamics of species and species complexes are considered on the basis of data on Late Cenozoic subfossil and fossil bone remains. Special attention is given to the objects to be reconstructed, the principles of their classification, and the concept concerning three scales of these dynamics: the actual, historical, and evolutionary scales. Published in Russian in Ekologiya, 2006, No. 6, pp. 452–456. The text was submitted by the author in English.     

Climatic dependence of the Late Holocene dynamics of tree species cenotypes in the intrazonal ecotone of Eastern Sayan forests

A comprehensive study of paleobotanical materials collected in the northern part of the Eastern Sayan was performed, including botanical analysis of peat, palynological and carpological analysis, and radiocarbon dating. The results provided a basis for reconstructing in detail the spatiotemporal distribution of ecocenotic complexes and corresponding paleoclimate types and calculating quantitative gradients of heat and moisture supply in the Late Holocene, beginning from 3500 ka.     

污泥衍生吸附剂对铅离子的吸附机理研究

研究了化学活化法热解制取污泥衍生吸附剂的工艺过程,得出相应工艺条件.利用污泥衍生吸附剂吸附溶液中重金属离子Pb2 ,得到动力学模型.实验结果表明:(1)该吸附过程分为3个阶段:初始阶段(t≤20 min)、过渡阶段(20 min＜t≤30 min)和后期阶段(t＞30 min),满足线性方程dC/dt=kC;(2)该吸附过程的吸附活化能E=26.5 kJ/mol,吸附频率因子A=6900 s-1.整个吸附过程为扩散吸附,吸附传质速度由孔隙扩散阶段和内表面吸附共同控制.     

Validation of geometry modelling approaches for offshore gas dispersion simulations

Computational Fluid Dynamics (CFD) codes are widely used for gas dispersion studies on offshore installations. The majority of these codes use single-block Cartesian grids with the porosity/distributed-resistance (PDR) approach to model small geometric details. Computational cost of this approach is low since small-scale obstacles are not resolved on the computational mesh. However, there are some uncertainties regarding this approach, especially in terms of grid dependency and turbulence generated from complex objects. An alternative approach, which can be implemented in general-purpose CFD codes, is to use body-fitted grids for medium to large-scale objects whilst combining multiple small-scale obstacles in close proximity and using porous media models to represent blockage effects. This approach is validated in this study, by comparing numerical predictions with large-scale gas dispersion experiments carried out in DNV GL's Spadeadam test site. Gas concentrations and gas cloud volumes obtained from simulations are compared with measurements. These simulations are performed using the commercially available ANSYS CFX, which is a general-purpose CFD code. For comparison, further simulations are performed using CFX where small-scale objects are explicitly resolved. The aim of this work is to evaluate the accuracy and efficiency of these different geometry modelling approaches.     

结合光谱法和计算模拟多角度分析2,2',4,4',5-五溴二苯醚与人血清白蛋白的作用机制

本文结合光谱法、动力学模拟(MD)和分子对接等手段,多角度地研究了2,2′,4,4′,5-五溴二苯醚(BDE-99)与人血清白蛋白(HSA)在pH=7.4模拟生理环境下的相互作用机制.首先采用MD从理论上模拟BDE-99与HSA相互作用的构象变化情况;然后利用同步荧光和三维荧光光谱法从实验角度进行验证,所得结果表明,BDE-99使HSA的疏水性增强从而导致其构象发生变化.同时,荧光光谱和紫外光谱得出BDE-99对HSA的猝灭机制属于静态猝灭和非辐射能量转移.另外,分子对接结果显示,BDE-99通过静电引力和疏水作用力结合在HSA的位点I处,这与竞争实验和热力学参数的分析结果是一致的.实验数据与模拟计算结果的相互印证,为进一步探究BDE-99和HSA的相互作用机制提供了重要的信息和参考依据.     

环境作用动力学在应力腐蚀断裂中的应用

目的研究材料的应力腐蚀断裂时间。方法应用环境作用动力学理论,求解材料的应力腐蚀断裂时间函数。结果从环境作用动力学理论得到了材料的应力腐蚀断裂时间函数,并对AZ61和AZ80镁合金进行了试验验证。结论环境作用动力学理论可以描述镁合金材料应力腐蚀断裂时间;AZ61镁合金抗应力腐蚀性能优于AZ80镁合金。