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Ecological and habitat ranges of orchids in the northernmost regions of their distribution areas:A case study from ural Mountains,Russia

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Plant Diversity 2023年第2期45卷 211-218页

作者： Irina A.Kirillova Yuriy A.Dubrovskiy Svetlana V.Degteva Alexander B.Novakovskiy institute of Biology of Komi Science Centre of the ural branch of the russian academy of sciences 28 Kommunisticheskaya St.167982SyktyvkarKomi RepublicRussia

The Orchidaceae,which is one of the most interesting families of angiosperms,contains a large number of rare *** their acknowledged importance,little attention has been paid to the study of orchids distributed in northern *** this study,we determined the syntaxonomical diversity and ecological parameters of orchid habitats in two of Europe's largest protected areas,the Pechoro-Ilychsky Reserve and the Yugyd Va National Park(northeastern European Russia),and then compared our findings to those in other parts of orchid distribution *** this purpose,we studied 345 descriptions of plant communities(releves) containing species from Orchidaceae and defined habitat parameters using Ellenberg indicator values with the community weight mean approach,nonmetric multidimensional scaling(NMS),and relative niche *** found that orchids were distributed in eight habitat types and 97 plant *** largest number of orchid species is found in forest *** of the orchid species under study occur in the mires and rock habitats with open *** orchids consistently occur in areas disturbed by human *** addition,our study indicates that the main drivers of orchid distribution across the vegetation types are light and soil *** analysis of the ecological parameters of orchid habitats indicates that some orchid species can be classified as habitat specialists that are confined to a relatively narrow ecological niche in the urals(e.g.,Goodyera repens,Cypripedium guttatum and Dactylorhiza maculata).Several other species(*** cordata and Dactylorhiza fuchsia) grow under diverse ecological parameters.

关键词： Orchidaceae Plant communities Nature protected areas Community weight mean Illumination Moisture

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SOME WEIGHT-TYPE HIGH-RESOLUTION DIFFERENCE SCHEMES AND THEIR APPLICATIONS

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Acta Mechanica Sinica 1999年第4期15卷 313-324页

作者：王汝权申义庆 institute of Computational mathematics and Scientific/Engineering Computing Chinese Academy of Sciences Beijing China 100080 LHD Institute of Mechanics Chinese Academy of Sciences Beijing China 100080

By the aid of an idea of the weighted ENO schemes, some weight-type high-resolution difference schemes with different orders of accuracy are presented in this paper by using suitable weights instead of the minmod functions appearing in various TVD schemes. Numerical comparisons between the weighted schemes and the non-weighted schemes have been done for scalar equation, one-dimensional Euler equations, two-dimensional Navier-Stokes equations and parabolized Navier-Stokes equations.

关键词： TVD schemes ENO schemes WENO schemes Euler equations Navier-Stokes equations

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A promising method for the analysis of notch effect on fatigue strength: Strain energy density approach

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Science China(Technological sciences) 2016年第10期59卷 1617-1618页

作者： SUN ChengQi HONG YouShi Key Laboratory of Nonlinear mechanics Institute of Mechanics Chinese Academy of Sciences University of Chinese academy of sciences

In recent years, the approach of strain energy density （SED） has received special attention in the analysis of notch effect on fatigue strength of notched components, e.g. ref. [1-3]. One of the fundamental contributions to SED-based approaches was by Sih [4,5] who proposed the SED factor S, which was defined as the product of the SED and a critical distance from the point of singularity. Thus, the failure is controlled by the critical value S~.

关键词：缺口效应疲劳强度密度法应变能强度影响 SED 参考文献临界距离

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Impact of Climate and Grazing on Biomass Components of Eastern Russia Typical Steppe

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Journal of Integrative Agriculture 2014年第6期13卷 1183-1192页

作者： Ubugunov Leonid Rupyshev Yuriy Ubugunov Vasiliy HOU Xiang-yang Vishnyakova Oxana Lavrentieva Irina Ubugunova Vera REN Wei-bo DING Yong institute of General and Experimental Biology Siberian Branch of Russian Academy of Sciences Grassland Research institute Chinese Academy of Agricultural Sciences

Spatial and structural characteristics of plant communities in the steppe ecosystems of the Baikal region, russian Federation have been researched in connection with climate change and grazing. The present study, based on a total of 15 typical steppe sampling plots, investigated above-ground biomass （AGB）, below-ground biomass （BGB）, total biomass （TB） and root：shoot ratios （R：S） and their relationships with climatic factors and grazing. All biomass components varied widely depending on the climatic parameters and the degree of grazing affected transformation. A strong negative correlation between mean annual temperature （MAT） and total plant biomass was revealed for all study area. Mean annual precipitation （MAP） signiifcantly affected communities productivity increasing only in the south of the region. Due to the large and mountainous territory, the inlfuence of latitude and elevation （mountain） factors on the components of the biomass were studied. Although all studied plant steppe communities were transformed by uncontrolled grazing, their productivity is signiifcantly reduced only at plots with maximum digression. Vegetation shift is an indicator of climate change, as well as providing a diagnostic tool to build predictive models. Based on the complex index of effective precipitation, it was revealed that at the end of last century in the steppes of the Baikal region the structural and production processes will be affected by an arid climate trend.

关键词： steppe productivity climate grazing transformation Baikal region

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Mechanism on progressive failure of a faulted rock slope due to slip-weakening

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Science China(Technological sciences) 2005年第z1期48卷 18-26页

作者： ZHANG Junfeng XU Yongjun QI Tao LI Zhengguo institute of mechanics Chinese Academy of Sciences Beijing 100080 China Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China

Slip-weakening is one of the characteristics of geological materials under certain loadings. Non-uniform rock structure may exist in the vicinity of the slip surface for a rock slope. Some portion of the slip surface may be penetrated but the other not. For the latter case, the crack or the fault surface will undergo shear deformation before it becomes a successive surface under a certain loading. As the slipped portion advances, slip-weakening occurs over a distance behind the crack tip. In the weakening zone, the shear strength will decrease from its peak value to residual friction level. The stress will redistribute along the surface of crack and in the weakening zone. Thus the changed local stress concentration leads the crack to extend and the ratio of penetration of the slip surface to increase. From the view of large-scale for the whole slip surface, the shear strength will decrease due to the damage of interior rock structure, and the faulted rock behaves as a softening material. Such a kind of mechanism performs in a large number of practical landslides in the zones experienced strong earthquakes. It should be noted that the mechanism mentioned above is different from that of the breakage of structural clay, in which the geological material is regarded as a medium containing structural lumps and structural bands. In this paper, the softening behavior of a faulted rock should be regarded as a comprehensive result of the whole complicated process including slip-weakening, redistribution of stress, extension of crack tip, and the penetration of the slip surface. This process is accompanied by progressive failure and abrupt structural damage. The size of slip-weakening zone is related to the undergoing strain. Once the relative slide is initiated (local or integrated), the effect of slip-weakening will behave in a certain length behind the crack tip until the formation of the whole slip surface.

关键词： faulted rock slope, slip-weakening, progressive failure.

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Distribution of algae and cyanobacteria of biological soil crusts along the elevation gradient in mountain plant communities at the Northern urals(russian European Northeast)

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Journal of Mountain Science 2022年第3期19卷 637-646页

作者： IV NOVAKOVSKAYA EN PATOVA YA DUBROVSKIY AB NOVAKOVSKIY EE KULYUGINA institute of Biology Komi Scientific CentreUral BranchRussian Academy of SciencesKommunisticheskaya st.28SyktyvkarKomi Republic167982Russia

This paper describes the biodiversity of cyanobacteria and microalgae of biological soil crusts(BSC)on bare substrates in different mountain vegetation types at the Northern *** total,we identified 99 algal species from six divisions in all sampled *** species diversity and structure of BSC algal communities show a relationship with environmental factors(altitude,soil p H and humidity,and illumination).Taxonomic diversity of algae decreases along the altitude gradient from mountain meadow to mountain *** and cyanobacteria species from six divisions were identified in meadow communities,five in mountain forests and four in mountain *** observed a positive correlation between species diversity of phototrophic microorganisms and altitude in the forest communities,but a negative correlation in the *** dominant complex of cyanobacterial and algal species in BSC was specific for each type of plant community and was reflective of the habitat *** species diversity and morphological organization of the BSC algae thalli can be used as a criterion for the ongoing assessment of climatic changes in high latitudes and mountain regions.

关键词： Biological soil crusts Cyanobacteria and microalgae Altitude gradient Northern urals

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A simple method to model the reduced environment of lake bottom sapropel formation

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Chinese Journal of Oceanology and Limnology 2017年第4期35卷 956-966页

作者： Olga L.GASKOVA Vera D.STRAKHOVENKO Nadezhda I.ERMOLAEVA Eugene Yu.ZARUBINA Ekaterina A.OVDINA V.S.Sobolev institute of Geology and Mineralogy Siberian Branch of the Russian Academy of Sciences Novosibirsk State University institute for Water and Environmental Problems Siberian Branch of the Russian Academy of Sciences

The Kambala and Barchin brackish lakes （Baraba steppe, southern West Siberia） contain an organic-rich sapropel layer that was formed in oxygen-depleted waters. We measured the bulk sediment elemental composition, the water chemistry and determined the mineralogical composition and predominant biota species （Diatoms and Cyanobacteria in phytoplankton community respectively） in the lakes. The result indicates that the first lake has a siliceous type of sapropel and the second a carbonaceous one. A computer thermodynamic model was developed for chemical interaction in water-bottom sediment systems of the Kambala and Barchin Lakes. The surface sodium bicarbonate waters are supersaturated with respect to calcite, magnesite （or low Mg-calcite）, quartz and chlorite with minor strontianite, apatite and goethite （pH 8.9-9.3, Eh 0.3 V）. Nevertheless, it is shown that during sapropel deposition, deep silt waters should be anoxic （Eh〈0 V）. The virtual component CH20 has been used to create an anoxic environment suitable for pyrite formation due to the biotic community impact and abiotic reduction. Thermodynamic calculation has shown that silt water is not necessarily euxinic （anoxic and sulfidic）. Depending on Eh, sulfate sulfur can dominate in solution, causing the formation of gypsum together with pyrite. An attempt was made to find a reason for solution supersaturation with respect to Ca and Mg ions due to their complexation with humic acids.

关键词： brackish lakes sapropel sediments mineral composition silica calcite thermodynamic calculations

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Impact of air drought on photosynthesis efficiency of the Siberian crabapple(Malus baccata L. Borkh.) in the forest-steppe zone of Transbaikalia, Russia

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Journal of Arid Land 2019年第2期11卷 255-266页

作者： Alexandr RUDIKOVSKII Elena RUDIKOVSKAYA Lyubov DUDAREVA Siberian institute of Plant Physiology and Biochemistry of Siberian branch Russian Academy of Sciences

The adaption of photosynthesis, being a key metabolic process, plays an important role in plant resistance to air drought. In this study, the Siberian crabapple(Malus baccata L. Borkh.) in the forest-steppe zone of Transbaikalia region, Russia, was subjected to air drought stress and its photosynthesis characteristics were analyzed. The results show that air drought and sufficient soil moisture supply lead to the decrease in the total chlorophyll(Chl) content, while the ratio of Chls to carotenoids is constant in the Siberian crabapple tree. The function of photosystem II(PS-II) in the crabapple trees is characterized by a decrease in the fraction of absorbed light energy spent on the photochemical work and an increase in the proportion of non-photosynthetic thermal quenching. These changes indicate the photosynthetic down-regulation that acts as a universal photoprotective mechanism. During the midday hours, the combination of high air temperature and low air humidity leads to the decrease in the maximum photochemical quantum yield of photosystem II(Fv/Fm) and the efficiency of photosynthesis(PABS). The parameters of leaf gas exchange show the significant differences in these values between the control and experimental variants. During the morning hours, the Siberian crabapple, growing in the Irkutsk City,assimilates carbon dioxide more intensively. Due to the higher air humidity, the stomata are kept open and the necessary amount of carbon dioxide entries the sites of carboxylation. The low air humidity combined with wind in the experimental variants leads to the unreasonably high water loss in the crabapple leaves by more than 27% as compared to the control variant(Irkutsk City). However, water use efficiency in the morning hours increases during plant photosynthetic processes, i.e., 42% higher than that of control. This,apparently, is a reflection of the adaptation processes of the Siberian crabapple to the air drought and parching wind.

关键词： air drought chlorophyll fluorescence leaf gas exchange pigments water use efficiency

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Preservation of Linear Constraints in Approximation of Tensors

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Numerical mathematics(Theory,Methods and Applications) 2009年第4期2卷 421-426页

作者： Eugene Tyrtyshnikov institute of Numerical mathematics of russian academy of sciences

For an arbitrary tensor(multi-index array) with linear constraints at each direction,it is proved that the factors of any minimal canonical tensor approximation to this tensor satisfy the same linear constraints for t... 详细信息

关键词： Multi-index arrays tensors linear constraints low rank approximation canonicaltensor decomposition multilevel matrices.

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Fast Revealing of Mode Ranks of Tensor in Canonical Form

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Numerical mathematics(Theory,Methods and Applications) 2009年第4期2卷 439-444页

作者： Dmitry V.Savostyanov institute of Numerical mathematics Russian Academy of Sciences

Considering the problem of mode ranks revealing of d-dimensional array (tensor) given in canonical form,we propose fast algorithm based on cross approximation of Gram matrices of unfoldings.

关键词： Multidimensional array canonical decomposition Tucker approximation fast recompression.

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