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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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Cu/TiO_(2) Photocatalysts for CO_(2) Reduction: Structure and Evolution of the Cocatalyst Active Form

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Transactions of Tianjin University 2024年第2期30卷 140-151页

作者： Andrey A.Saraev Anna Yu.Kurenkova Denis D.Mishchenko Alexandr l.trigub Evgeniy Yu.Gerasimov Ekaterina A.Kozlova Boreskov Institute of Catalysis Lavrentieva Ave 5Novosibirsk 630090Russia Synchrotron Radiation Facility SKIF Boreskov Institute of CatalysisNikol’skiy Ave 1Kol’tsovo 630559Russia National Research Center “Kurchatov Institute”Kurchatova Sq 1Moscow 123182Russia

Extensive work on a Cu-modified TiO_(2) photocatalyst for CO_(2) reduction under visible light irradiation was conducted. The structure of the copper cocatalyst was established using UV-vis diff use refl ectance spectroscopy, high-resolution transmis- sion electron microscopy, X-ray absorption spectroscopy, and X-ray photoelectron spectroscopy. It was found that copper exists in different states (Cu 0 , Cu^(+) , and Cu^(2+) ), the content of which depends on the TiO_(2) calcination temperature and copper loading. The optimum composition of the cocatalyst has a photocatalyst based on TiO_(2) calcined at 700℃ and modified with 5 wt% copper, the activity of which is 22 μmol/(h·g cat ) (409 nm). Analysis of the photocatalysts after the photocatalytic reaction disclosed that the copper metal on the surface of the calcined TiO_(2) was gradually converted into Cu_(2) O during the photocatalytic reaction. Meanwhile, the metallic copper on the surface of the noncalcined TiO_(2) did not undergo any trans- formation during the reaction.

关键词： Photocatalysis Photocatalytic CO_(2)conversion Visible light Titanium dioxide Copper Copper oxides Methane formation Photocatalyst transformation

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Development of 3D Scanning System for Robotic Plasma Processing of Medical Products with Complex Geometries

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Journal of Electronic Science and Technology 2020年第3期18卷 212-222页

作者： Darya l.Alontseva Elaheh Ghassemieh alexander l.Krasavin Albina T.Kadyroldina School of Information Technology and Intelligent Systems D.Serikbayev East Kazakhstan State Technical UniversityUst-Kamenogorsk 070004 Wolfson School of Mechanical Electrical and Manufacturing EngineeringLoughborough UniversityLoughborough LE113TU

This paper describes the development of an intelligent automated control system of a robot manipulator for plasma treatment of medical implants with complex *** two-layer coatings from the Ti wire and hydroxyapatite powders are applied on the surface of Ti medical implants by microplasma spraying to increase the biocompatibility of *** coating process requires precise control of a number of parameters,particularly the plasma spray distance and plasma jet traverse ***,the development of the robotic plasma surface treatment involves automated path *** key idea of the proposed intelligent automatic control system is the use of data of preliminary three-dimensional (3D) scanning of the processed implant by the robot *** segmentation algorithm of the point cloud from laser scanning of the surface is *** methodology is suitable for robotic 3D scanning systems with both non-contact laser distance sensors and video cameras,used in additive manufacturing and medicine.

关键词： Plasma processing point cloud robot manipulator surface segmentation three-dimensional(3D)scanning

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Update on herbal and dietary supplement-induced liver injury:current gaps and future directions

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Hepatobiliary Surgery and Nutrition 2023年第5期12卷 752-755页

作者： Sabine Weber alexander l.Gerbes Department of Medicine II University HospitalLMU MunichMunichGermany

Drug-induced liver injury(DIlI)is a rare but potentially life-threatening condition,which accounts for the majority of acute liver failure cases in the US and *** direct hepatoxicity,which is mainly caused by acetaminophen,idiosyncratic DIlI is unpredictable and occurs unrelated to the dose or frequency of the ***,DIlI cannot only be caused by a large variety of prescription drugs,but also by herbal and dietary supplements(HDS).While HDS-DIlI has already played a role in Asian countries like China or Korea for a long time,there is also an increasing incidence of HDS-DIlI in countries with formerly less HDS-DIlI cases such as the US,presumably due to a rising usage of those remedies(1).

关键词： Herbal and dietary supplements(HDS) liver injury hepatoxicity autoimmune liver diseases

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Parasites of the liver:A global problem?

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World Journal of Gastroenterology 2024年第30期30卷 3554-3559页

作者： Vladislav V Tsukanov alexander V Vasyutin Julia l Tonkikh Clinical Department of the Digestive System Pathology of Adults and Children Federal Research Center“Krasnoyarsk Science Center”of the Siberian Branch of the Russian Academy of SciencesScientific Research Institute of Medical Problems of the NorthKrasnoyarsk 660022Russia

Parasitic liver diseases can be caused by trematodes,cestodes,nematodes,and *** pathology is significant because millions of people in different parts of the world have liver parasites,which can manifest themselves in the development of inflammation,liver cysts,cholecystitis,cholelithiasis,pancreatitis and liver cirrhosis that are often threatening their *** International Agency for Research on Cancer considers three species of trematodes,Schistosoma haematobium,Opisthorchis viverrini and Clonorchis sinensis,to be *** modern examination methods,in some cases including extensive screening of large populations,are required for diagnosing liver *** of parasitic liver diseases is differentiated and can involve a combination of surgical and therapeutic *** is no doubt that the clinical and epidemiological scale allows one to regard parasitic liver diseases as a global healthcare problem.

关键词： liver Parasites Epidemiology Diagnosis Clinics Treatment Echinococcosis Opisthorchiasis Fascioliasis Schistosomiasis

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Phase field modeling with large driving forces

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npj Computational Materials 2023年第1期9卷 623-631页

作者： Jin Zhang alexander F.Chadwick David l.Chopp Peter W.Voorhees Department of Materials Science and Engineering Northwestern UniversityEvanstonIL 60208USA Department of Engineering Sciences and Applied Mathematics Northwestern UniversityEvanstonIL 60208USA

There is growing interest in applying phase field methods as quantitative tools in materials discovery and ***,large driving forces,common in many materials systems,lead to unstable phase field profiles,thus requiring fine spatial and temporal *** demands more computational resources,limits the ability to simulate systems with a suitable size,and deteriorates the capability of quantitative ***,we develop a strategy to map the driving force to a constant perpendicular to the *** with the third-order interpolation function,we find a stable phase field profile that is independent of the magnitude of the driving *** power of this approach is illustrated using three *** demonstrate that by using the driving force extension method,it is possible to employ a grid size orders of magnitude larger than traditional *** approach is general and should apply to many other phase field models.

关键词： forces interpolation apply

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Mitochondrial transplantation strategies as potential therapeutics for central nervous system trauma

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Neural Regeneration Research 2018年第2期13卷 194-197页

作者： Jenna l.Gollihue Samir P.Patel alexander G.Rabchevsky Spinal Cord and Brain Iniury Research Center University of KentuckyLexingtonKYUSA Separtment of Physiology University of KentuckyLexingtonKYUSA

Mitochondria are essential cellular organelles critical for generating adenosine triphosphate for cellular homeostasis, as well as various mechanisms that can lead to both necrosis and apoptosis. The field of ＂mi- tochondrial medicine＂ is emerging in which injury/disease states are targeted therapeutically at the level of the mitochondrion, including specific antioxidants, bioenergetic substrate additions, and membrane uncoupling agents. Consequently, novel mitochondrial transplantation strategies represent a potentially multifactorial therapy leading to increased adenosine triphosphate production, decreased oxidative stress, mitochondrial DNA replacement, improved bioenergetics and tissue sparing. Herein, we describe briefly the history of mitochondrial transplantation and the various techniques used for both in vitro and in vivo delivery, the benefits associated with successful transference into both peripheral and central nervous system tissues, along with caveats and pitfalls that hinder the advancements of this novel therapeutic.

关键词： oxygen consumption bioenergetics oxidative phosphorylation cellular uptake replacement strategies spinal cord injury mitochondria

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Raman lasing and soliton mode-locking in lithium niobate microresonators

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light(Science & Applications) 2020年第1期9卷 1925-1931页

作者： Mengjie Yu Yoshitomo Okawachi Rebecca Cheng Cheng Wang Mian Zhang alexander l.Gaeta Marko loncar Department John A.Paulson School of Engineering and Applied Sciences Harvard UniversityCambridgeMA 02138USA Department of Applied Physics and Applied Mathematics Columbia UniversityNew YorkNY 10027USA Department of Electronic Engineering&State Key laboratory of Terahertz and Millimeter Waves City University of Hong KongKowloonHong KongChina Hyperlight Corporation 501 Massachusetts AvenueCambridgeMA 02139USA

The recent advancement in lithium-niobite-on-insulator(lNOI)technology is opening up new opportunities in optoelectronics,as devices with better performance,lower power consumption and a smaller footprint can be realised due to the high optical confinement in the *** lNOI platform offers both largeχ(2)andχ(3)nonlinearities along with the power of dispersion engineering,enabling brand new nonlinear photonic devices and applications for the next generation of integrated photonic ***,Raman scattering and its interaction with other nonlinear processes have not been extensively studied in dispersion-engineered lNOI *** this work,we characterise the Raman radiation spectra in a monolithic lithium niobate(lN)microresonator via selective excitation of Raman-active phonon *** dominant mode for the Raman oscillation is observed in the backward direction for a continuous-wave pump threshold power of 20mW with a high differential quantum efficiency of 46%.We explore the effects of Raman scattering on Kerr optical frequency comb *** achieve mode-locked states in an X-cut lNOI chip through sufficient suppression of the Raman effect via cavity geometry *** analysis of the Raman effect provides guidance for the development of future chip-based photonic devices on the lNOI platform.

关键词： scattering pump lithium

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Neotectonic transpressional intraplate deformation in eastern Eurasia: Insights from active fault systems in the southeastern Korean Peninsula

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Geoscience Frontiers 2023年第4期14卷 123-136页

作者： Namgwon Kim Seung-Ik Park Chang Soo Cho Youngbeom Cheon alexander l.Peace Department of Geology Kyungpook National UniversityDaegu 41566Republic of Korea Earthquake Research Center Korea Institute of Geosciences and Mineral ResourcesDaejeon 34132Republic of Korea Active Tectonics Research Center Korea Institute of Geosciences and Mineral ResourcesDaejeon 34132Republic of Korea School of Earth Environment and SocietyMcMaster UniversityHamiltonON L8S 4K1Canada

Transpression occurs in response to oblique convergence across a deformation zone in intraplate regions and plate *** Korean Peninsula is located at an intraplate region of the eastern Eurasian Plate and has been deformed under the ENE–WSW maximum horizontal compression since the late *** this study,we analyzed short-term instrumental seismic(focal mechanism)and long-term paleoseis-mic(Quaternary fault outcrop)data to decipher the neotectonic crustal deformation pattern in the south-eastern Korean ***(paleo-)seismic data acquired from an NNE–SSW trending deformation zone between the Yangsan and Ulleung fault zones indicate spatial partitioning of crustal deformation by NNW–SSE to NNE–SSW striking reverse faults and NNE–SSW striking strike-slip faults,supporting a strike-slip partitioned transpression *** instantaneous and finite neotectonic strains,estimated from the focal mechanism and Quaternary outcrop data,respectively,show discrepan-cies in their axes,which can be attributed to the switching between extensional and intermediate axes of finite strain during the accumulation of wrench-dominated ***,some major faults,including the Yangsan and Ulsan fault zones,are relatively misoriented to slip under the current stress condition but,paradoxically,have more(paleo-)seismic records indicating their role in accommodating the neotectonic transpressional *** propose that fluids,heat flow,and lithospheric structure are potential factors affecting the reactivation of the relatively misoriented major *** findings provide insights into the accommodation pattern of strain associated with the neotectonic crustal extrusion in an intraplate region of the eastern Eurasian Plate in response to the collision of the Indian Plate and the sub-duction of the Pacific/Philippine Sea Plates.

关键词： Transpression Strike-slip partition Intraplate strain accommodation Fault-slip analysis Slip tendency analysis

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The evolution of refertilized lithospheric mantle beneath the northeastern Siberian craton:links between mantle metasomatism,thermal state and diamond potential

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Geoscience Frontiers 2022年第6期13卷 153-169页

作者： Sergei Skuzovatov Vladislav S.Shatsky Alexey l.Ragozin alexander P.Smelov Vinogradov Institute of Geochemistry Russian Academy of SciencesSiberian Branch1AFavorskogo Str.Irkutsk 664033Russia Sobolev Institute of Geology and Mineralogy Russian Academy of SciencesSiberian Branch3Koptyug Ave.Novosibirsk 630090Russia Geology&Geophysics Department Novosibirsk State University2 Pirogova Str.Novosibirsk 630090Russia Diamond and Precious Metal Geology Institute Russian Academy of SciencesSiberian Branch39Lenina Ave.Yakutsk 677000Russia

Although the diamond potential of cratons is linked mainly to thick and depleted Archean lithospheric keels, there are examples of craton-edge locations and circum-cratonic Proterozoic terranes underlain by diamondiferous mantle. Here, we use the results of comprehensive major and trace-element studies of detrital garnets from diamond-rich late Triassic(Carnian) sedimentary rocks in the northeastern Siberia to constrain the thermal and chemical state of the pre-Triassic mantle and its ability to sustain the diamond storage. The studied detrital mantle-derived garnets are dominated by low-to mediumCr lherzolitic(~45%) and low-Cr megacrystic(~39%) chemistries, with a significant proportion of eclogitic garnets(~11%), and only subordinate contribution from harzburgitic garnets(~5%) with variable CrOcontents(1.2–8.4 wt.%). low-Cr megacrysts display uniform, “normal” rare-earth element(REE)patterns with no Eu/Eu* anomalies, systematic Zr and Ti enrichment(mainly within 2.5–5), which are evidence of their crystallization from deep metasomatic melts. lherzolitic(G9) garnets exhibit normal or humped to MREE-depleted sinusoidal REE patterns and elevated Nd/Y(up to 0.33–0.41) and Zr/Y ratios(up to 7.62). Rare low-to high-Cr harzburgitic(G10) garnets have primarily “depleted”, sinusoidal REEpatterns, low Ti, Y and HREE, but vary significantly in Zr-Hf, Ti and MREE-HREE contents, Nd/Y(within 0.1–2.4) and Zr/Y(1.53–19.9) ratios. The observed trends of chemical enrichment from the most depleted,harzburgitic garnets towards lherzolitic(including high-Ti high-Cr G11-type) garnets and megacrysts result from either voluminous high-temperature metasomatism by plume-derived silicate melts or recurrent mobilization of less voluminous kimberlitic or related carbonated mantle melts, rather than the initially primitive, fertile nature of the Proterozoic SClM. Calculated Ni-in-garnet temperatures(primarily within ~1150–1250 ℃) indicate their derivation from at least ~220 km thick Cr-undersa

关键词： Siberian craton Kimberlite Diamond placers Peridotites Eclogites Megacrysts

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