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Quantum spin Hall effect in inverted InAs/GaSb quantum wells

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Frontiers of physics 2012年第2期7卷 200-207页

作者： ivan Knez (1) Rui-Rui Du (1) 1. Department of Physics and Astronomy Rice University Houston TX 77251-1892 USA

We review the recent experimental progress towards observing quantum spin Hall effect in inverted InAs/GaSb quantum wells （QWs）. Low temperature transport measurements in the hybridization gap show bulk conductivity of a non-trivial origin, while the length and width dependence of con- ductance in this regime show strong evidence for the existence of helical edge modes proposed by Liu et al. [Phys. Rev. Lett., 2008, 100： 236601]. Surprisingly, edge modes persist in spite of compa- rable bulk conduction and show only weak dependence on magnetic field. We elucidate that seeming independence of edge on bulk transport comes due to the disparity in Fermi-wave vectors between the bulk and the edge, leading to a total internal reflection of the edge modes.

关键词： quantum spin Hall effect InAs/GaSb quantum wells topological insulators

Approximation of thermoelasticity contact problem with nonmonotone friction

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Applied Mathematics and Mechanics(English Edition) 2010年第1期31卷 77-86页

作者： ivan ESTak Boko S. JOVANOVI Faculty of Mine and Geology University of Belgrade Faculty of Mathematics University of Belgrade

The paper presents the formulation and approximation of a static thermoelasticity problem that describes bilateral frictional contact between a deformable body and a rigid foundation. The friction is in the form of a nonmonotone and multivalued law. The coupling effect of the problem is neglected. Therefore, the thermic part of the problem is considered independently on the elasticity problem. For the displacement vector, we formulate one substationary problem for a non-convex, locally Lipschitz continuous functional representing the total potential energy of the body. All problems formulated in the paper are approximated with the finite element method.

关键词： static thermoelastic contact nonmonotone multivalued friction hemivari-ational inequality substationary problem finite element approximation

Neuroprotective therapy for retinal neurodegenerative diseases by stem cell secretome

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Neural Regeneration Research 2021年第1期16卷 117-118页

作者： Ricardo Usategui-Martín ivan Fernandez-Bueno Instituto Universitario de Oftalmobiología Aplicada(IOBA) Retina GroupUniversidad de ValladolidValladolidSpain Centro en Red de Medicina Regenerativa y Terapia Celular de Castilla y León Red Temática de Investigación Cooperativa en SaludOftaredInstituto de Salud Carlos IIIValladolidSpain

Retinal neurodegenerative diseases like agerelated macular degeneration,glaucoma,diabetic retinopathy or retinitis pigmentosa are the most frequent causes of incurable low vision and blindness *** had been estimated that the prevalence of these diseases varies between 1/750 and 1/5000 depending on the region,the level of consanguinity or ethnicity(Na et al.,2017).The functional and structural complexity of the retina makes it susceptible to multiple types of pathogenic damage.

关键词： diseases protective degenerative

Geochemistry of cryoconite and soils in the Central Caucasus region and its environmental implications

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Journal of Mountain Science 2021年第12期18卷 3109-3124页

作者： ivan KUSHNOV Evgeny ABakUMOV Rustam TEMBOTOV Vyacheslav POLYakOV Saint Petersburg State University 7/9 University EmbankmentSt Petersburg 199034Russian Federation Tembotov Institute of Ecology of Mountain Territories Russian Academy of Sciences37-a I.Armand Str.Nalchik360051Russian Federation

Climate change and deglaciation are active processes in current changing *** the Central Caucasus region rapid degradation of glaciers is caused often by the formation of superficial blackcolored *** plays a crucial role in changing ecosystems and may contribute to the formation of primary soils after glacier *** the past 20 years,the frequency of mudflows and other dangerous mountain events have increased in the Central Caucasus,which is associated with the glacial *** of tourism results in increasing of traffic,recreational activity and environment *** of the cryoconites geochemical properties in comparison with other types of sediments and local soils is crucial for investigation of geochemistry and contamination state of superficial glacial *** environmental aspect is important in terms of the Central Caucasus settlements safety under conditions of deglaciation and anthropogenic *** sediments studied(cryoconite,mudflow,moraine)were sampled at Garabashi and Skhelda glaciers as well as some local soils at the Baksan *** materials were investigated in terms of physicochemical and agrochemical *** concentrations of trace elements(Cu,Pb,Zn,Ni,Cd)were also determined and contamination indices(geoaccumulation index-Igeo,contamination factor-CF and degree of contamination-Cdegree)were used to evaluate the pollution status of studied *** obtained shows much higher content of organic carbon in soils(up to 7.82%)in comparison with cryoconite(max.1.63%)due to presence of vegetation,however,the basal respiration values in some cases were similar betweenсryoconite and soils,indicating high rates of microbial activity in a cryoconite *** was found that almost all materials studied have sandy *** sediments on both of the glaciers are enriched with phosphorus,high values of K_(2)O(max.298 mg·kg^(-1))and N-NH4(max.

关键词： Cryoconite Trace elements Entisols Contamination Central Caucasus

Magnetic Moment Tensor Potentials for collinear spin-polarized materials reproduce different magnetic states of bcc Fe

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npj Computational Materials 2022年第1期8卷 107-112页

作者： ivan Novikov Blazej Grabowski Fritz Körmann Alexander Shapeev Skolkovo Institute of Science and Technology Skolkovo Innovation CenterNobel St.3Moscow143026Russia Institute for Materials Science University of StuttgartPfaffenwaldring 5570569StuttgartGermany Computational Materials Design Max-Planck-Institut für Eisenforschung GmbHD-40237DüsseldorfGermany Materials Science and Engineering Delft University of Technology2628 CDDelftThe Netherlands

We present the magnetic Moment Tensor Potentials(mMTPs),a class of machine-learning interatomic potentials,accurately reproducing both vibrational and magnetic degrees of freedom as provided,e.g.,from first-principles *** accuracy is achieved by a two-step minimization scheme that coarse-grains the atomic and the spin *** performance of the mMTPs is demonstrated for the prototype magnetic system bcc iron,with applications to phonon calculations for different magnetic states,and molecular-dynamics simulations with fluctuating magnetic moments.

关键词： magnetic fluctuating states

International scientific communications in the field of colorectal tumour markers

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World Journal of Gastrointestinal Surgery 2017年第5期9卷 127-138页

作者： Krasimir ivanov ivan Donev Department of General and Operative Surgery Professor Paraskev Stoyanov Medical University of Varna Clinic of Medical Oncology St. Marina University Hospital of Varna

AIM To analyze scientometrically the dynamic science internationalization on colorectal tumour markers as reflected in five information portals and to outline the significant journals, scientists and *** A retrospective problem-oriented search was performed in Web of Science Core Collection(Wo S), MEDLINE, BIOSIS Citation Index(BIOSIS) and Scopus for 1986-2015 as well as in Dervent Innovations Index(Derwent) for 1995-2015. Several specific scientometric parameters of the publication output and citation activity were comparatively analyzed. The following scientometric parameters were analyzed:(1) annual dynamics of publications;(2) scientific institutions;(3) journals;(4) authors;(5) scientific forums;(6) patents-number of patents, names and countries of inventors, and(7) citations(number of citations to publications by single authors received in WoS, BIOSIS Citation Index and Scopus).RESULTS There is a trend towards increasing publication output on colorectal tumour markers worldwide along with high citation rates. Authors from 70 countries have published their research results in journals and conference proceedings in 21 languages. There is considerable country stratification similar to that in most systematic investigations. The information provided to end users and scientometricians varies between these data-bases in terms of most parameters due to different journal coverage, indexing systems and editorial policy. The lists of the so-called "core" journals and most productive authors in Wo S, BIOSIS, MEDLINE and Scopus along with the list of the most productive authors-inventors in Derwent present a particular interest to the beginners in the field, the institutional and national science managers and the journal editorial board members. The role of the purposeful assessment of scientific forums and patents is emphasized. CONCLUSION Our results along with this problem-oriented collection containing the researchers' names, addresses and publication

关键词： Colorectal tumour markers Scientometrics International scientific communications Web of Science MEDLINE BIOSIS Scopus Derwent

Channeling of fast ions through the bent carbon nanotubes： The extended two-fluid hydrodynamic model

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Chinese Physics B 2016年第4期25卷 274-283页

作者： Lazar Karbunar Dusko Borka ivan Radovic Zoran L Miskovic School of Electrical Engineering University of Belgrade Bulevar Kralja Aleksandra 73 11120 Belgrade Serbia Vinca Institute of Nuclear Sciences University of Belgrade P. O. Box 522 11001 Belgrade Serbia Department of Applied Mathematics and Waterloo Institute for Nanotechnology University of Waterloo Waterloo Ontario Canada N2L 3G1

We investigate the interactions of charged particles with straight and bent single-walled carbon nanotubes （SWNTs） under channeling conditions in the presence of dynamic polarization of the valence electrons in carbon, This polarization is described by a cylindrical, two-fluid hydrodynamic model with the parameters taken from the recent modelling of several independent experiments on electron energy loss spectroscopy of carbon nano-structures. We use the hydrodynamic model to calculate the image potential for protons moving through four types of SWNTs at a speed of 3 atomic units. The image potential is then combined with the Doyle-Turner atomic potential to obtain the total potential in the bent carbon nanotubes. Using that potential, we also compute the spatial and angular distributions of protons channeled through the bent carbon nanotubes, and compare the results with the distributions obtained without taking into account the image potential.

关键词： nanotubes channeling dynamic polarization

Integrated view of plant metabolic defense with particular focus on chewing herbivores

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Journal of Integrative Plant Biology 2022年第2期64卷 449-475页

作者： David Wari Takako Aboshi Tomonori Shinya ivan Galis Institute of Plant Science and Resources Okayama UniversityKurashiki710-0046 Japan Faculty of Agriculture Yamagata UniversityWakaba-machiTsuruoka997-8555 Japan

Success of plants largely depends on their ability to defend against *** emergence of the first voracious consumers,plants maintained adapting their structures and chemistry to escape from *** constant pressure was further accelerated by adaptation of herbivores to plant defenses,which all together sparked the rise of a chemical empire comprised of thousands of specialized metabolites currently found in *** diversity in the plant kingdom is truly amazing,and although many plant metabolites have already been identified,a large number of potentially useful chemicals remain unexplored in plant ***,biosynthetic routes for plant metabolites involve many enzymes,some of which still wait for identification and biochemical ***,regulatory mechanisms that control gene expression and enzyme activities in specialized metabolism of plants are scarcely ***,understanding of how plant defense chemicals exert their toxicity and/or repellency against herbivores remains limited to typical examples,such as proteinase inhibitors,cyanogenic compounds and *** this review,we attempt summarizing the current status quo in metabolic defense of plants that is predominantly based on the survey of ubiquitous examples of plant interactions with chewing herbivores.

关键词： defense herbivore mode of action plant specialized metabolism

Migration of organic carbon and trace elements in the system glacier-soil in the Central Caucasus alpine environment

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Journal of Mountain Science 2022年第12期19卷 3458-3474页

作者： ivan KUSHNOV Evgeny ABakUMOV Rustam TEMBOTOV Timur NIZAMUTDINOV Saint Petersburg State University 7/9 University EmbankmentSt Petersburg199034Russia Tembotov Institute of Ecology of Mountain Territories of Russian Academy of Sciences 7a I.Armand StreetNalchik360051Russia

Rapid deglaciation is one of the most important challenges in the Earth science *** reason of this is specific supraglacial sediments–cryoconites,which represent carbon-containing dust with organomineral matter and living *** of physical and chemical characteristics of cryoconites in the Central Caucasus is necessary in order to understand their influence on alpine territories biogeochemical cycles,pollution and development in conditions of intensive glacial melting and active anthropogenic *** this research cryoconites as well as moraines,soil-like bodies and soils have been sampled from the alpine Bezengi Glacier and adjacent Khulamo-Bezengi *** physicochemical features(pH values,total organic carbon content,microbial respiration,particle-size distribution)as well as content of trace elements have been defined in sampled materials and several pollution indices(Geoaccumulation index,Contamination factor and Degree of pollution)have been *** obtained show low values of total organic carbon in cryoconites(max.0.23%)but high values(max.7.54%)in top horizon of soils located in floodplain,indicating its active fluvioglacial transfer which may further accelerate the development of *** activity in the studied soils was mostly influenced by additional input of labile organic carbon from cryoconites with water ***-size distribution was similar among the studied cryoconites,indicating dominance of sand fraction(up to 85.28%)while studied soils showed higher variability due to influence of *** the trace elements,cryoconites were mostly polluted by Zn(max.85.70 mg·kg^(-1))which corresponds to high pollution according to pollution indices;Pb(max.24.90 mg·kg^(-1))and Cu(max.17.40 mg·kg^(-1)),up to moderate pollution *** of polluted cryoconite material as well as local anthropogenic activities increased pollution of periglacial soils by Zn(max.89.20 mg·kg^(-1)),Pb(m

关键词： Cryoconites Umbrisols Leptosols Pollution Caucasus mountain range