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Epiphytic orchids and their ecological niche under anthropogenic influence in central Himalayas,Nepal

Journal of Mountain Science 2016年第5期13卷 774-784页

作者： ADHIKARI Yagya Prasad FISCHER anton FISCHER Hagen Siegfried Geobotany Department of Ecology and Ecosystem ManagementTechnische Universit?t München

The survival chance of epiphytie orchids today not only depends on the natural site conditions required by the orchids but also on anthropogenic changes in site conditions. This study answers two questions：（1） What is the ecological niche of the different epiphytic orchid species？（2） What are the ecological factors that threaten epiphytic orchid＇s population under anthropogenic disturbances？ Our study area was the Kathmandu valley, Nepal, with its subtropical forest. We established 156 systematically selected sampling points in the Kathmandu area covering different types of ecosystems under human impacts such as densely populated area, agricultural land, mixed agricultural and settled area, old tree patches, and a natural forest in a national park. The ecological niche of the orchid species was analyzed with a principal component analysis （PCA）. The correlations between the different site factors were statistically significant. Spearman＇s rank correlation matrices showed that the variables land-use intensities with altitude, and height with diameter in breast height （dbh） of host had the highest significant positive correlation coefficient （0.67 and 0.64 respectively）. On the other hand, host bark pH and altitude as well as land use had a significantly strong negative correlation coefficient （-0.80 and -0.61, respectively）. Different epiphytic orchid species interact differently with the given set of environmental factors： for occurrence of Vanda cristata there is no single environmental factor of special influence, while for Rhynehostylis retusa high bark pH and high light availability are important. First two axis of the PCA explained more than 50% of the total variance. Most orchid species occupy a specific, narrow niche in this ecological space. The main causes of anthropogenie influence of orchid population in the Kathmandu Valley are loss of adequate host trees （species and size） and increasing air pollution, resulting in increasing host bark pH.

关键词： Host characteristics Epiphytic orchids Anthropogenic disturbances Canopy ecosystem Ecological niche Himalayas

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Micro-site Conditions of Epiphytic Orchids in a Human Impact Gradient in Kathmandu Valley, Nepal

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Journal of Mountain Science 2012年第3期9卷 331-342页

作者： Yagya Prasad ADHIKARI anton FISCHER Hagen Siegfried FISCHER Geobotany Department of Ecology and Ecosystem Management Technische Universitt München Hans-Carl-von-Carlowitz-Platz 2 D-85354 Freising Germany

We studied distribution and site conditions of epiphytic orchids in a gradient of human interference in Kathmandu valley, central Nepal. The aim was to understand the recent distribution pattern of epiphytic orchids, with respect to (i) the micro-site conditions and (ii) the type and intensity of land use. The occurrence of epiphytic orchids was recorded for a grid with 1.5 km cell size. The cells represent different types and intensities of human impact. Site factors such as bark rugosity, bark pH, diameter at breast height (dbh; 1.3 m) of host trees, exposure to wind and sunlight intensity were recorded. With regard to the species richness and abundance of epiphytic orchids, we compared different human impact categories from very strong human impact (settlement area) to very low human impact (national park). Remote sensing was used for a supervised classification of land cover. Ficus religiosa turned out to be the most important host species for orchids in urban areas, while Schima wallichii and Alnus nepalensis significantly host orchids in the other categories. Both species richness and abundance of epiphytic orchids were significantly higher under very low human impact (forest in national park) and also some remaining patches of primary forest than the other regions. Micro-climate is crucial for orchid populations. Host bark pH, bark rugosity, sunlight intensity and host exposure were significantly different for all human impact categories in order to harbour epiphytic orchid species. Habitats with a mixture of mature trees are suitable and essential for the conservation of viable populations of epiphytic orchids in settled areas. The study reveals that to improve the population size of orchids it is essential for future urban forestry to: (i) Protect old trees as carriers of existing epiphytic orchid diversity, (ii) protect medium old trees to ensure that they may become old trees, (iii) plant new host trees for the future, (iv) plant in groups instead of sing

关键词： Human impact Host tree Micro-climate Epiphytic orchids Remote sensing Conservation Nepal

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Production of electrical energy from living plants in microbial fuel cells

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Clean Energy 2023年第2期7卷 408-416页

作者： Raymond Daniel Rodriguez Martinez Maria Eugenia alvarez Bermudez Department of Industrial Production Faculty of EngineeringUniversidad Metropolitana1073 CaracasVenezuela Department of Energy and Automation Faculty of EngineeringUniversidad Metropolitana1073 CaracasVenezuela

Growing energy demand is a current problem with greater incidence in the *** research objective is to establish seed bases to give a leading role to plants used in anthropogenic production activities and consumption,and even plants belonging to wildlife in terms of energy *** use of living plants to obtain electrical energy through a microbial-vegetable fuel cell is proposed as a mech-anism to supply the energy demand with easy access worldwide,especially in areas far from urban *** this work,the voltage produced by microbial-vegetable fuel cells was measured using graphite electrodes and plants belonging to the species of aloe(Aloe vera),corn(Zea mays),black beans(Phaseolus vulgaris),tomato(Solanum lycopersicum)and moss(Dicranidae).They were selected for their presence in everyday life and their great commercial and agricultural value,reaching a maximum voltage of 884 mV from *** is evidence that all plants can be a source of energy to a greater or lesser extent and that their performance is given by the plant root interactions at the ***,an extensive root system can favour the accumulation of substrate after the hydrolysis of dead roots,provided that their presence does not interfere with microbial activity on the anodic *** this,using plants with low resistance to thermal stress can lead to a substrate richer in substances that can be ***,it is recommended to use plants according to their life cycle and the morphology of their roots,and plants that can grow in waterlogged conditions or without direct contact with the Sun.

关键词： ecosystems microorganisms renewable energy photosynthesis sustainability

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Finding Symmetry Groups of Some Quadratic Programming Problems

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Numerical Mathematics(Theory,Methods and Applications) 2023年第2期16卷 370-392页

作者： anton V.Eremeev Alexander S.Yurkov Sobolev Institute of Mathematics SB RAS Omsk DepartmentOmskRussia Omsk Scientific Center SB RAS(Institute of Radiophysics and Physical Electronics) OmskRussia

Solution and analysis of mathematical programming problems may be simplified when these problems are symmetric under appropriate linear *** particular,a knowledge of the symmetries may help decrease the problem dimension,reduce the size of the search space by means of linear *** the previous studies of symmetries in the mathematical programming usually dealt with permutations of coordinates of the solutions space,the present paper considers a larger group of invertible linear *** study a special case of the quadratic programming problem,where the objective function and constraints are given by quadratic *** formulate conditions,which allow us to transform the original problem to a new system of coordinates,such that the symmetries may be sought only among orthogonal *** particular,these conditions are satisfied if the sum of all matrices of quadratic forms,involved in the constraints,is a positive definite *** describe the structure and some useful properties of the group of symmetries of the *** that,the methods of detection of such symmetries are outlined for different special cases as well as for the general case.

关键词： Non-convex programming orthogonal transformation symmetry group Lie group

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Twisted photons: new quantum perspectives in high dimensions

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Light(Science & Applications) 2017年第1期6卷 181-191页

作者： Manuel Erhard Robert Fickler Mario Krenn anton Zeilinger Vienna Center for Quantum Science&Technology(VCQ) Faculty of PhysicsUniversity of ViennaBoltzmanngasse 5Vienna 1090Austria Institute for Quantum Optics and Quantum Information(IQOQI) Austrian Academy of SciencesBoltzmanngasse 3Vienna 1090Austria Department of Physics University of OttawaOttawaOntario K1N 6N5Canada

Twisted photons can be used as alphabets to encode information beyond one bit per single *** ability offers great potential for quantum information tasks,as well as for the investigation of fundamental *** this review article,we give a brief overview of the theoretical differences between qubits and higher dimensional systems,qudits,in different quantum information *** then describe recent experimental developments in this field over the past three ***,we summarize some important experimental and theoretical questions that might be beneficial to understand better in the near future.

关键词： entanglement high-dimensional quantum systems orbital-angular-momentum of photons quantum communication

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Effect of Alloying Elements on Microstructure,Martensitic Transformation and Mechanical Properties of Ni-Mn Based Alloys

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Journal of Materials Science & Technology 2009年第5期25卷 649-654页

作者： K.alvarez H.Y.Kim S.Miyazaki Graduate School University of TsukubaIbaraki 305-8573Japan Institute of Materials Science University of TsukubaTsukubaIbaraki 305-8573Japan

The microstructural features, shape memory behavior and mechanical properties of Ni-Mn based alloys were investigated by differential scanning calorimetry （DSC）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM） and thermal cycling test under various stresses. The transformation temperatures shifted toward lower temperatures when adding a third element into the Ni-Mn system. The addition of 10 at. pct Fe increased considerably the mechanical properties exhibiting still high transformation temperatures. However, it was found that in NiMn40Fe10 alloy the martensitic transformation is not thermoelastic in nature. The mechanism of this transformation and the crystallography of Ni-Mn（50-x）-Fex （x=5, 7, 10, 20 at. pct） alloys are presented.

关键词： Ni-Mn based alloys Martensitic transformation temperature L10 phase

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Complementarity between quantum coherence and mixedness:a majorization approach

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Communications in Theoretical Physics 2023年第5期75卷 73-83页

作者： Yanet alvarez Marcelo Losada Mariela Portesi Gustavo M Bosyk Instituto de Física La Plata CONICET–UNLP1900 La PlataArgentina Facultad de Ciencias Exactas Universidad Nacional de La Plata1900 La PlataArgentina Facultad de Matemática AstronomíaFísica y ComputaciónUniversidad Nacional de Córdoba5000 CórdobaArgentina

Quantum coherence is a relevant resource for various quantum information processing tasks,but it is fragile since it is generally affected by environmental *** is reflected in the loss of purity of the system,which in turn limits the amount of quantum coherence of *** a consequence,a complementarity relation between coherence and mixedness *** works characterize this complementarity through inequalities between theℓ1-norm of coherence and linear entropy,and between the relative entropy of coherence and von Neumann ***,coherence-mixedness complementarity is expected to be a general feature of quantum systems,regardless of the measures ***,an alternative approach to coherence-mixedness complementarity,based on majorization theory,is *** quantifiers of coherence and mixedness,namely the coherence vector and the spectrum,respectively,are used,instead of scalar measures.A majorization relation for the tensor product of both vectorial quantifiers is obtained,capturing general aspects of the trade-off between coherence and *** optimal bound for qubit systems and numerical bounds for qutrit systems are ***,coherence-mixedness complementarity relations are derived for a family of symmetric,concave and additive *** results provide a deeper insight into the relation between quantum coherence and mixedness.

关键词： coherence mixedness complementarity majorization

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Correlation analysis among vorticity,Q method and Liutex

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Journal of Hydrodynamics 2020年第6期32卷 1207-1211页

作者： Yifei Yu Pushpa Shrestha Oscar alvarez Charles Nottage Chaoqun Liu Department of Mathematics the University of Texas at ArlingtonArlington76019USA

Influenced by the fact that vorticity represents rotation for rigid body,people believe this idea also works for fluid ***,the vortex predictions by vorticity do not match experimental results,which drove scientists to look for more appropriate methods to identify *** vortex identification methods can be categorized into three *** vorticity-based method is classified as the first *** relying on eigenvalues of velocity gradient tensor are considered as the second *** still believe vorticity is vortex since vorticity theory looks correct in mathematics,but all other methods are only scalars and unable to indicate the swirl ***,a new vortex identification method called Liutex is *** is regarded as the third-generation method,not only overcoming all previous methods’drawbacks but also having a clear physical *** direction of Liutex represents the swirl axis of rotation,and its strength is equal to twice the angular *** this paper,we did a correlation analysis between vorticity,Q,λ_(ci),λ_(2)methods and Liutex based on a direct numerical simulation(DNS)case of boundary layer *** results show that the correlation between vorticity and Liutex is very small or even negative in strong shear regions,which demonstrates that using vorticity to detect vortex lacks scientific foundation and vorticity is not appropriate to represent *** correlation analysis also shows that the second generation is contaminated too by shear and thus is not accurate to identify the vortex structure.

关键词： Correlation Liutex vorticity Q method λ_(ci)method λ_(2)method

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SnO2-reduced graphene oxide nanoribbons as anodes for lithium ion batteries with enhanced cycling stability

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Nano Research 2014年第9期7卷 1319-1326页

作者： Lei Li anton Kovalchuk James M. Tour Department of Chemistry Rice University 6 I00 Main Street Houston Texas 77005 USA Richard E. Smalley Institute for Nanoscale Science and Technology Rice University 6100 Main Street Houston Texas 77005 USA Department of Materials Science and NanoEngineering Rice University 6100 Main Street Houston Texas 77005 USA

A nanocomposite material of SnO2-reduced graphene oxide nanoribbons has been developed. In this composite, the reduced graphene oxide nanoribbons are uniformly coated by nanosized SnO2 that formed a thin layer of SnO2 on the surface. When used as anodes in lithium ion batteries, the composite shows outstanding electrochemical performance with the high reversible discharge capacity of 1,027 mAh/g at 0.1 A/g after 165 cycles and 640 mAh/g at 3.0 A/g after 160 cycles with current rates varying from 0.1 to 3.0 A/g and no capacity decay after 600 cycles compared to the second cycle at a current density of 1.0 A/g. The high reversible capacity, good rate performance and excellent cycling stability of the composite are due to the synergistic combination of electrically conductive reduced graphene oxide nanoribbons and SnO2, The method developed here is practical for the large-scale development of anode materials for lithium ion batteries.

关键词： lithium ion battery tin oxide graphene oxide nanoribbons energy storage

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Techno-economic assessment of providing control energy reserves with a biogas plant

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Frontiers of Chemical Science and Engineering 2018年第4期12卷 763-771页

作者： Ervin Saracevic David Woess Franz Theuretzbacher anton Friedl Angela Miltner Institute of Chemical Environmental and Bioscience EngineeringTU Wien1060 ViennaAustria University of Natural Resources and Life Sciences 1180 ViennaAustria University of Applied Sciences 2700Wiener NeustadtAustria

Grid stability is being challenged by the increasing integration of power plants with volatile power generation into the energy system. Power supply fluctuations must be compensated by energy system flexibility. The storability of the energy carrier enables biogas plants to generate power flexibly. In this study, the technical and economic effects of providing positive secondary control energy reserves with an Austrian biogas plant were assessed. The plant's main focus lies in biomethane production with the option of heat and power generation through combined heat and power (CHP) units. A detailed simulation model of the investigated biogas plant was developed, which is presented in this work. Ex-post simulations of one year of flexible plant operation were conducted with this model. The findings show that the installed biogas storage capacity is sufficient to provide control energy reserves while simultaneously producing biomethane. Profitability of providing control energy reserves largely depends on the prices at the control energy market and on CHP unit start-up costs. A cost efficiency analysis demonstrated that investing in a hot water tank with a volume of 5 m(3) for short-term heat storage turned out to be economically viable.

关键词： biogas plant process simulation control energy reserves economic assessment gas storage

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