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The state of gold in phases of the Cu-Fe-S system:In situ X-ray absorption spectroscopy study

Geoscience Frontiers 2023年第3期14卷 103-116页

作者： Boris R.Tagirov Olga N.Filimonova Alexander l.Trigub Ilya V.Vikentyev Elena V.Kovalchuk Maximilian S.Nickolsky Andrey A.Shiryaev vladimir l.reukov Dmitry A.Chareev Institute of Geology of Ore Deposits(IGEM RAS) 35Staromonetnyi per119017 MoscowRussia National Research Centre‘Kurchatov Institute’ 1Akademika Kurchatova pl123182 MoscowRussia Institute of Physical Chemistry and Electrochemistry(IPCE RAS) 31Leninsky Prospect119071 MoscowRussia Institute of Experimental Mineralogy(IEM RAS) 142432 ChernogolovkaMoscow RegionRussia

Chalcopyrite and bornite are the main Au-bearing minerals at Cu porphyry deposits,volcanogenic massive sulfide(VMS)deposits,Cu-Ni deposits of the mafic magmatic complexes,and ores of submarine sulfide *** and intermediate solid solutions with wide compositional variations(bnss and iss–high-temperature chalcopyrite,correspondingly),which can scavenge economic concentrations of Au,appear in the Cu-Fe-S system at ore-forming ***,the state of Au in bnss and iss is yet *** solve this conundrum,we synthesized samples with net chemical composition of bnss and iss,studied them by in situ X–ray absorption spectroscopy(XAS),and used the experimental data to explain the Au distribution among natural ore-forming *** sulfide samples were obtained at 495–700℃ in Au-saturated system by means of salt flux *** bnss contained1.2–1.6 log units more Au than iss:up to 18 wt.%Au in bnss vs 0.4 wt.%Au in iss at 700*** increase of temperature resulted in the sharp increase of Au concentration in both phases,1 log unit per 100℃ at f(S2)close to S_((l)) *** of Au l_(3)-edge spectra recorded at 25–675℃ revealed that at 25℃ Au exists mainly in the metallic *** t>500℃ the spectral features of Audisappear,and “chemically bound”Au *** Au form of occurrence in the iss field is interpreted as Au-bearing clusters with a stromeyerite-like(CuAgS)*** Cu_(2–x)S and bnss contain Au in a mixture of stromeyeritelike and petrovskaite-like(Au_(0.8)Ag_(1.2)S)*** chemical composition of both forms is close to CuAuS,where the nearest Au neighbors are two S atoms at R_(Au-S)=2.34–2.36Å.Results of the present study allow to determine the state of Au and its concentration in the main Cu-bearing minerals of sulfide ores as a function of the T-f(S_(2))-compositional *** to the sharp increase of the CuAuS clusters stability with increasing temperature,in high-temperature ores formed at t>350℃ A

关键词： “Invisible”gold Bornite solid solution Intermediate solid solution Digenite Chalcopyrite X-ray absorption spectroscopy

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A theory to link relationships of stand volume,density,mean diameter and height in forestry data

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Journal of Forestry Research 2021年第1期32卷 15-20页

作者： vladimir l.Gavrikov Chair of Ecology and Environmental Studies Institute Ecology and GeographySiberian Federal University79 pr.SvobodnyiKrasnoyarskRussian Federation 660041

In this study,a geometric model of a growing forest stand has been *** basic relationships considered link stand volume and stand density,diameter at breast height(DBH),mean DBH and mean *** model provides simple formulas connecting the exponents of all the *** of the formulas to real forestry data provided a high level of predictions of an exponent from two others measured through regressions from empirical *** Pinus sylvestris *** were of a static nature,a collection of individual stands,while the Pseudotsuga menziesii(Mirb.)Franco data were dynamic,representing forest stand development over *** ability of the model to predict exponents in the empirical data implies,on the one hand,a substantial level of similarity between the model and the forestry ***,on the other hand,the model gives an example in which parameters of one relationship may be linked to parameters of *** this kind of‘relationship between relationships’may be observed in forest stands undergoing active growth and competition-induced self-thinning.

关键词： Relationship between relationships Selfthinning Forestry data Allometry Scots pine Douglasfir

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‘Relationships between relationships’ in forest stands: intercepts and exponents analyses

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Journal of Forestry Research 2018年第3期29卷 575-582页

作者： vladimir l.Gavrikov Institute for Ecology and Geography Chair of Ecology and Environmental Studies Siberian Federal University

Relationships between diameter at breast height(dbh) versus stand density, and tree height versus dbh(height curve) were explored with the aim to find if there were functional links between correspondent parameters of the relationships, exponents and intercepts of their power functions. A geometric model of a forest stand using a conic approximation suggested that there should be interrelations between correspondent exponents and intercepts of the relationships. It is equivalent to a type of ‘relationship between relationships’ that might exist in a forest stand undergoing self-thinning, and means that parameters of one relationship may be predicted from parameters of another. The predictions of the model were tested with data on forest stand structure from published databases that involved a number of trees species and site quality levels. It was found that the correspondent exponents and intercepts may be directly recalculated from one another for the simplest case when the total stem surface area was independent of stand density. For cases where total stem surface area changes with the drop of density, it is possible to develop a generalization of the model in which the interrelationships between correspondent parameters(exponents and intercepts) may be still established.

关键词： Total stem surface area Self-thinning Conic approximation Power function Exponent Intercept Scots pine

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Elaboration of a conceptual solution for the development of the Arctic shelf from seasonally flooded coastal areas

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International Journal of Mining Science and Technology 2022年第1期32卷 113-119页

作者： vladimir S.litvinenko Mikhail V.Dvoynikov vladimir l.Trushko Saint-Petersburg Mining University Saint-Petersburg 199106Russia

Currently,construction of facilities in the Arctic is carried out on sand islands,but there are limitations for remote coastal *** restrictions are associated with the lack of quarries with construction sand in the immediate vicinity of the work site,as well as the risk of seasonal flooding of the *** article includes conceptual solutions for construction of modular piling in Arctic nearshore conditions,upon which drilling rigs and auxiliary equipment can be placed for the purpose of subsequent wildcatting,development and exploratory extended reach drilling wells(with measured depth about 15000 m).During the construction of the modular piling foundations,a mathematical simulation of the thermodynamic condition of the frozen ground was conducted,and the bearing capacity of the foundations was *** proposed solutions will solve these problems by constructing modular pile foundations and placing the necessary infrastructure on them,taking into account the distribution of loads during operation in seasonally flooded areas.

关键词： Drilling&drillholes Stress analysis Offshore engineering Infrastructure planning Geotechnical engineering Extended reach drilling

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Penile prosthesis implantation and tunica albuginea incision without grafting in the treatment of Peyronie＇s disease with erectile dysfunction

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Asian Journal of Andrology 2013年第3期15卷 391-394页

作者： Miroslav l Djordjevic vladimir Kojovic School of Medicine University of Belgrade Belgrade 11000 Serbia

We evaluated penile prosthesis implantation with tunica albuginea-relaxing incisions without grafting in the treatment of Peyronie＇s disease associated with erectile dysfunction. Between April 2005 and June 2011, 62 patients underwent surgery due to severe Peyronie＇s disease associated with erectile dysfunction. Malleable and inflatable penile prostheses were inserted in 49 and 13 cases, respectively. Penile prostheses were inserted into the corpora cavernosa using the standard ventral approach. After lifting the neurovascular bundle, the tunica albuginea was incised and opened at the plaque region to correct the deformities and to lengthen the penis. Subsequently, the wide neurovascular bundle was replaced, and all incisions of the tunica albuginea were covered to prevent corporal grafting. In the median follow-up of 35 months （range 14-82 months）, the penis was completely straightened in 59 （95%） patients. Numbness of the glans, which the patients found initially upsetting, decreased or disappeared spontaneously 3-6 months later. Penile prosthesis implantation with tunica albuginea incisions is a viable alternative in the treatment of Peyronie＇s disease because the extensive dissection of the neurovascular bundle allows a good approach to the plaque and provides excellent covering of the incised tunica albuginea without additional grafting.

关键词： erectile dysfunction neurovascular bundle penile prosthesis Peyronie's disease tunica albuginea

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Humanization for neurological disease modeling:A roadmap to increase the potential of Drosophila model systems

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Animal Models and Experimental Medicine 2023年第3期6卷 230-236页

作者： vladimir l.Katanaev Department of Cell Physiology and Metabolism Faculty of MedicineUniversity of GenevaGenevaSwitzerland HumanaFly Facility Faculty of MedicineUniversity of GenevaGenevaSwitzerland

Neuroscience and neurology research is dominated by experimentation with *** 75%of neurology disease-associated genes have orthologs in Drosophila mel-anogaster,the fruit fly amenable to complex neurological and behavioral ***,non-vertebrate models including Drosophila have so far been unable to significantly replace mice and rats in this field of *** reason for this situ-ation is the predominance of gene overexpression(and gene loss-of-function)meth-odologies used when establishing a Drosophila model of a given neurological disease,a strategy that does not recapitulate accurately enough the genetic disease condi-tions.I argue here the need for a systematic humanization approach,whereby the Drosophila orthologs of human disease genes are replaced with the human *** approach will identify the list of diseases and the underlying genes that can be adequately modeled in the fruit fly.I discuss the neurological disease genes to which this systematic humanization approach should be applied and provide an example of such an application,and consider its importance for subsequent disease modeling and drug discovery in Drosophila.I argue that this paradigm will not only advance our un-derstanding of the molecular etiology of a number of neurological disorders,but will also gradually enable researchers to reduce experimentation using rodent models of multiple neurological diseases and eventually replace these models.

关键词： disease modeling Drosophila humanization neurological diseases

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Perturbation finite element solution for chemo-elastic boundary value problems under chemical equilibrium

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Acta Mechanica Sinica 2019年第5期35卷 981-991页

作者： Peter l.Bishay Jan Sladek Nicholas Fabry vladimir Sladek Chuanzeng Zhang College of Engineering and Computer Science California State UniversityNorthridgeCAUSA Institute of Construction and Architecture Slovak Academy of SciencesBratislavaSlovakia Department of Civil Engineering University of Siegen57068 SiegenGermany

Modeling the elastic behavior of solids in energy conversion and storage devices such as fuel cells and lithium-ion batteries is usually difficult because of the nonlinear characteristics and the coupled chemo-mechanical behavior of these *** this work,a perturbation finite element(FE)formulation is developed to analyze chemo-elastic boundary value problems(BVPs)under chemical *** perturbation method is applied to the FE equations because of the nonlinearity in the chemical potential expression as a function of solute *** compositional expansion coefficient is used as the perturbation *** the perturbation expansion,a system of partial differential equations for the displacement and dimensionless solute concentration functions is obtained and solved in consecutive *** presence of a numerical solution enables modeling 3D chemo-elastic solids,such as battery electrodes or ionic gels,of any geometric shape with defects of different *** proposed method is tested in several numerical examples such as plates with circular or elliptical holes,and *** numerical examples showed how the shape of the defect can change the distribution of solute concentration around the *** in chemo-elastic solids create sharp peaks in solute concentration around crack tips,and the intensity of these peaks increases as the far field solute concentration decreases.

关键词： Chemical potential Solute concentration Compositional expansion coefficient 2D stationary problem

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Bluetooth<sup>TM</sup>Enabled Acceleration Tracking (BEAT) mHealth System: Validation and Proof of Concept for Real-Time Monitoring of Physical Activity

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E-Health Telecommunication Systems and Networks 2013年第3期2卷 49-57页

作者： Aleksey Shaporev Mathew Gregoski vladimir reukov Teresa Kelechi David Morgan Kwartowitz Frank Treiber Alexey Vertegel Bioengineering Department Clemson University Clemson USA College of Nursing Medical University of South Carolina Charleston USA

Physical activity is critical to improve the condition of patients with chronic leg and foot ulcers, especially those who are obese and experienced multiple co-morbid conditions. Unfortunately, these individuals are unable to engage in guideline based physical activity (PA) programs. A prototype of BluetoothTM enabled acceleration tracking (BEAT) mHealth system was developed and manufactured for remote monitoring and stimulation of adherence to PA in deconditioned patients. The system consists of a miniature accelerometer-based sensor, smartphone application, and a network service. Validation testing showed high reliability and reproducibility of the BEAT sensors. Pilot study with human subjects demonstrated high accuracy of the BEAT system in recognition of different exercises and calculating overall outcomes of PA. Taken together, these results indicate that BEAT system could become a valuable tool for realtime monitoring of PA in deconditioned patients.

关键词： mHealth Accelerometer Sensor Physical Activity Monitoring

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Multifunctional interleaved geometric-phase dielectric metasurfaces

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light(Science & Applications) 2017年第1期6卷 668-674页

作者： Elhanan Maguid Igor Yulevich Michael Yannai vladimir Kleiner Mark l Brongersma Erez Hasman Micro and Nanooptics laboratory Faculty of Mechanical Engineeringand Russell Berrie Nanotechnology InstituteTechnion-Israel Institute of TechnologyHaifa 32000Israel Geballe laboratory for Advanced Materials Stanford University476 Lomita MallStanfordCA 94305USA

Shared-aperture technology for multifunctional planar systems,performing several simultaneous tasks,was first introduced in the field of radar *** photonics,effective control of the electromagnetic response can be achieved by a geometric-phase mechanism implemented within a metasurface,enabling spin-controlled phase *** synthesis of the shared-aperture and geometric-phase concepts facilitates the generation of multifunctional *** shared-aperture geometric-phase metasurfaces were realized via the interleaving of sparse antenna sub-arrays,forming Si-based devices consisting of multiplexed geometric-phase *** study the performance limitations of interleaved nanoantenna arrays by means of a Wigner phasespace distribution to establish the ultimate information capacity of a metasurface-based photonic *** these limitations,we present multifunctional spin-dependent dielectric metasurfaces,and demonstrate multiple-beam technology for optical rotation *** also demonstrate the possibility of achieving complete real-time control and measurement of the fundamental,intrinsic properties of light,including frequency,polarization and orbital angular momentum.

关键词： geometric phase metasurface multifunctional shared aperture spectropolarimetry spin-optics Wigner distribution

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Effect of Y_2O_3 and Total Oxide Addition on Mechanical Properties of Pressureless Sintered β-SiC

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Journal of Materials Science & Technology 2003年第3期19卷 193-196页

作者： vladimir D.Krstic Centre for Manufacturing of Advanced Ceramics and Nanomaterials Queen’s UniversityNicol HallKingstonOntarioCanada K7L 3N6

The effect of Y203 and the total oxide volume fraction (Y203+AI203) on density and mechanical properties of low temperature (1770-1940℃) pressureless sintered β-SiC ceramics were presented. The optimum temperature for pressureless sintering of β-SiC was found to be -1850℃ and the optimum content of Y203 in the oxides was found to be between 40 and 57 wt pct. The highest sintered density was achieved by adding oxides at 14 vol. pct. Both of the highest strength and fracture toughness were achieved at -14 vol. pct oxide addition and yttria concentrations between 40 and 57 wt pct in the oxides. Hardness, on the other hand, was found to be the highest for samples with 14 vol. pct oxide addition and -64 wt pct Y2O3 in oxides.

关键词： Y_2O_3 SiC Mechanical properties Sintering

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