检索结果-南通市图书馆

Ni_3Ga中间相结构缺陷的热力学和统计热力学分析

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

北京科技大学学报 2000年第3期22卷 202-204页

作者：袁文霞乔芝郁 o.Ssemenova H.Ipser 北京科技大学冶金学院北京100083 Universitat Wien Institut fur Anorganische Chemie

使用以稳定的Zro2为电解质的高温固体电解质电池电动势方法测量了Ni3Ga非整比金属间化合物1073至1273K均相范围内Ga的活度，计算了偏摩尔焓和偏摩尔摘等热力学性质．考虑4种点缺陷，即分别在2个亚晶格上的反结构原子和空位共存于该Ll2... 详细信息

使用以稳定的Zro2为电解质的高温固体电解质电池电动势方法测量了Ni3Ga非整比金属间化合物1073至1273K均相范围内Ga的活度，计算了偏摩尔焓和偏摩尔摘等热力学性质．考虑4种点缺陷，即分别在2个亚晶格上的反结构原子和空位共存于该Ll2型化合物中，各缺陷生成自由能为可调参数：Ef（Aβ）＝0．60eV，Ef（Bα）＝0．60eV，EfV（α）＝1．5eV，EfV（β）＝2．0eV，用统计热力学方法推导了Ni3Ga非整比化合物均相范围内缺陷浓度及其与温度和成分的关系，得到1123K时整比处的无序参数a’＝0．0009．

关键词：金属间化合物结构缺陷统计热力学 Ni3Ga

Structural Features of Nuclei in Leaf Mesophyll Cells of Salt-Tolerant Artemisia marschalliana

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

CellBio 2024年第1期13卷 1-6页

作者： Galina semenova Institute of Theoretical and Experimental Biophysics of Russian Academy of Sciences Pushchino Russia

All nuclei in mesophyll cells of Artemisia marschalliana are located in vacuoles and occupy up to 90% of their volume. The ultrastructural organization of chromatin in nuclei shows different degrees of its decondensation, up to complete separation of DNA from histones. It is possible that the separation of DNA from histones enables Artemisia to grow in soils with high salinity.

关键词： Meso- and Ultrastructure of Mesophyll Decondensation of Nuclear Chromatin Artemisia marschalliana

Possible Nature of an Electron Dense Substance in the Thylakoid Lumen of Chloroplasts

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

CellBio 2023年第2期12卷 11-17页

作者： Galina semenova Institute of Theoretical and Experimental Biophysics of Russian Academy of Sciences Pushchino Russia

The fixation of leaves of Tanacetum vulgare L. in glutaraldehyde makes it possible to isolate chloroplasts without sacrificing an electron dense substance in the thylakoid lumen. The extraction of lipids from the chloroplasts isolated from the leaves preliminarily fixed in glutaraldehyde has demonstrated that glycerolipids (galactolipids and phospholipids) are not manifested in TLC, whereas isoprenoid lipids (chlorophyll, carotenoids) are manifested. Presumably, isoprenoid lipids are not fixed with glutaraldehyde and are extracted from the thylakoid membrane. The ultrastructural control demonstrates that the electron dense substance from the thylakoid lumen is also extracted. It is possible that this substance is of isoprenoid nature.

关键词： Tanacetum vulgare L. Intrathylakoid Electron Dense Substance Glutar Chlo-roplasts Ultrastructure TLC of Lipids

The structure of colloidal polyethylenimine-silica nanocomposite microparticles

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2023年第5期76卷 86-100页

作者： Alexandra semenova Luke W.Giles Mark Louis P.Vidallon Bart Follink Paul L.Brown Rico F.Tabor School of Chemistry Monash University19 Rainforest Walk.Clayton3800Australia Rio Tinto Bundoora Technical Development Centre1 Research AvenueBundoora3083Australia

Deposition of silica from an organosilane tetraethoxysilane(TEoS)onto parent polyethylenimine(PEI)microgel particles produces a novel PEI-silica nanocomposite,which possesses greater adsorption ca-pacity for copper ions than either parent *** study explores factors governing interactions of silica with the PEI matrix,along with structural features of resulting PEI-silica composite particles,to explain their properties and determine their application *** influence of initial TEoS/PEI mass ratio and the duration of silica deposition on the final silica content and distribution in the composite are studied.A comparative analysis of the structural architecture of chemically etched silica remnants,original PEI-silica composite particles and the parent PEI-microgel is carried out using X-ray photo-electron spectroscopy,small-angle X-ray scattering,and electron microscopy *** is found that silica sol nanoparticles are evenly distributed throughout the PEI-microgel framework and interlinked with it via electrostatic interactions,enabling a structural model of the PEI-silica nanocomposite to be *** chemical stability of resulting nanocomposite particles in parallel with the parent PEI-microgel is tested and shown to be robust for more than 100 days of storage in aqueous dispersions across a range of pH conditions,highlighting the application potential for these particles in copper capture.

关键词： Polyethylenimine Silica organic-inorganic composite Nano-scale morphology Small angle X-ray scattering

Temperature dependence of LiNbo3 dislocation density in the near-surface layer

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese optics Letters 2022年第6期20卷 40-46页

作者： oksana semenova Aleksei Sosunov Nikolai Prokhorov Roman Ponomarev Department of Nanotechnology and Microsystems Engineering Perm State UniversityPerm 614990Russia Perm Federal Research Center of the Ural Branch of the Russian Academy of Sciences Perm 614990Russia

Density of dislocations in the near-surface layer was investigated in X-cut LiNbo_(3) depending on thermal annealing in the temperature range of 400℃–600℃.A dynamic model of randomly distributed dislocations has been developed for LiNbo_(3) by using X-ray *** experimental results showed that the dislocation density of the near-surface layer reached the minimum at the thermal annealing temperature of 500℃,with the analysis being performed when wet selective etching and X-ray diffraction methods were *** concluded that homogenization annealing is an effective technique to improve the quality of photonic circuits based on LiNbo_(3).The results obtained are important for optical waveguides,LiNbo_(3)-on-insulator-based micro-photonic devices,electro-optical modulators,sensors,etc.

关键词： lithium niobate etching pits near-surface layer density of dislocations annealing X-ray diffraction

Regional Atmospheric Blocking in the Drought Periods in Ukraine

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Journal of Earth Science and Engineering 2013年第5期3卷 341-348页

作者： Inna G. semenova Department of Theoretical Meteorology and Meteorological Forecasts Odessa State Environmental University Odessa 65016Ukraine

The conditions for regional circulation of the atmosphere in the periods of severe droughts in Ukraine are described by two circulation indexes. In analogy with experimental index EBI （European Blocking Index） for the Eastern Atlantic and Western Europe is proposed a new index ECBI （European Continental Blocking Index）, which describes the blocking of zonal flow over the European continent. The obtained time series of the ECBI for the spring-summer seasons with the severe droughts in Ukraine were analyzed. Katz circulation index was used for the estimating of intensity of the meridional atmospheric processes during the same droughts. It is shown that there registered a high frequency of blocking processes which was accompanied by positive phases of ECBI and an increase in the meridional component of an atmospheric flow over the region of Europe. In years with droughts in average 60% consecutive pentads were with a positive value of ECBI, mostly in April to May. The absolute maximum duration of blocking was the 10 consecutive pentads and observed in 1963. The high positive values of the ECBI and Katz index were connected with strong anomalies in seasonal and monthly fields of wind over territory of Eastern Europe. A close relationship between the ECBI and the Katz index was obtained, which allowed to determine the critical value of the Katz index for the beginning of blocking situation,

关键词： Atmospheric blocking blocking index circulation index drought.

Combined Effect of Water Deficit and Salt Stress on the Structure of Mesophyll Cells in Wheat Seedlings

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

CellBio 2014年第1期3卷 14-24页

作者： Galina semenova Irina Fomina Anatoly Ivanov Institute of Basic Biological Problems Russian Academy of Sciences Pushchino Russia Institute of Basic Biological Problems Russian Academy of Sciences Pushchino Russia Biosphere Systems International Foundation Tucson USA. Institute of Theoretical and Experimental Biophysics Russian Academy of Sciences Pushchino Russia

The purpose of the work was to assess the combined effect of drought and salinity (50, 100, 200 mМ NaCl) on the meso- and ultrastructure of mesophyll cells of wheat seedlings. Stress development was estimated by a decrease in the relative water content (RWC) and Co2-dependent o2 evolution (An) in leaves. The decrease in the RWC and in An occurred rapidly in the absence of salt in the substrate and slowly in the presence of salt, especially at a treatment of 100 mM NaCl. The resumption of watering led to the recovery of the both parameters in all variants except one with 200 mM NaCl. Structural studies showed that a weak drought stress (RWC 60%) without salinity led to the destruction of cell membranes and hyaloplasm, which did not occur in all salt treatments. By contrast, the ultrastructure of nuclei in weak drought without salinity remained unchanged, whereas in all salt treatments chromatin changed substantially. Heterochromatin underwent a strong condensation followed by the fusion into a united mass with the simultaneous loss of electron density. A strong water stress (RWC 40%) in all variants led to cell destruction and the hydrolysis of cell compounds. Under the drought without salinity, vacuoles disappeared, whereas in salt-treated samples they were retained and filled with organelles being at different degrees of degradation. Cell nuclei under strong drought stress lost their rounded shape, nuclear envelopes were destroyed, and at the end only a finely dispersed substance remained. Thus, under the combined action of drought and salt, there is some critical level of salt concentration in substrate above which the effect of NaCl changes to the adverse, which enhances the action of drought. Among structural components of mesophyll cells, the most sensitive parts to NaCl are nuclei and their chromatin.

关键词： Chromatin Meso- and Ultrastructure of Mesophyll Salt and Water Stress Triticum aestivum

Asymmetry in Value Relevance of Environmental Performance （EP） Information： Contingency Effects of Size and Industry

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Modern Accounting and Auditing 2013年第6期9卷 777-789页

作者： Natalia semenova Lars G. Hassel Abo Akademi University Turku Finland Umea University Umea Sweden

Contemporary research documents a positive but weak price premium from environmental performance （EP）. The specific circumstances of pricing EP of large and small companies and in polluting and clean industries have not, however, been investigated. This study predicts that financial markets price EP beyond financial fundamentals differently, depending on company size and the environmental risk of the industry and provides evidence relying on a set of the Sweden Stock Market 300 （SIX 300） companies listed on the Stockholm Stock Exchange （oMX Stockholm）. Applying a value relevance model, the average results are in line with previous findings that EP adds value beyond the book value of equity and earnings. The asymmetry in EP is, however, driven by company size and the environmental risk of the industry. This study suggests that large companies in low-risk industries obtain strong price premiums from being environmental industry leaders. In contrast, small companies and also companies in high-risk industries do not necessarily accrue the same market benefits.

关键词： environmental performance (EP) market premium industry risk size moderated regression analysis (MRA)

Value of Corporate Responsibility

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Value of Corporate Responsibility