检索结果-南通市图书馆

Nano Research 2023年第7期16卷 10222-10233页

作者： vadim I.Avilov Roman v.Tominov Zakhar E.vakulov Lev G.Zhavoronkov vladimir A.Smirnov Research Laboratory Neuroelectronics and Memristive Nanomaterials(NEUROMENA Lab) Southern Federal UniversityTaganrog 347922Russia Institute of Nanotechnologies Electronics and Electronic Equipment EngineeringSouthern Federal UniversityTaganrog 347922Russia

The paper shows the results of the mathematical model development and the numerical simulation of the oxygen vacancies,and the distribution of TiO,Ti_(2)O_(3),and TiO_(2)oxides in the titanium oxide nanostructure obtained by local anodic oxidation(anodization).The effect of the anodization voltage pulse duration and amplitude on the titanium oxide composition distribution and the conduction channel formation was *** device prototypes based on electrochemical titanium oxide are fabricated and *** was shown that forming free resistive switching between the low resistances state(LRS)1.43±0.54 kΩand the high resistance state(HRS)28.75±9.75 kΩwere observed during 100,000 switching cycles and LRS 1.49±0.23 kΩwas maintained for 10,000 *** resistive switching of the synaptic device prototype was *** was shown that increasing Uset from 0.5 to 1.5 v leads to different LRS from 3.96±0.19 to 0.71±0.10 kΩ.The results obtained can be used in the development of technological foundations for the formation of high-performance multilevel artificial synapses for elements of neuroelectronics and hardware neural networks.

关键词： artificial intelligence neuromorphic systems memristive cross bar resistive switching scanning probe microscopy titanium oxide

Tunable order in colloids of hard magnetic hexaferrite nanoplatelets

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2022年第2期15卷 898-906页

作者： Artem A.Eliseev Lev A.Trusov Evgeny O.Anokhin Andrei P.Chumakov vladimir v.Korolev Anastasia E.Sleptsova Peter Boesecke vladimir Ya.Shur vladimir YaShur Pavel E.Kazin Andrei A.Eliseev Faculty of Chemistry Moscow State UniversityLeninskie Gory lb3Moscow 119991Russia Department of Materials Science MSU-BIT UniversityShenzhen 517182China Faculty of Materials Science Moscow State UniversityLeninskie Gory lb73Moscow 119991Russia European Synchrotron Radiation Facility Avenue des Martyrs 71Grenoble 38043France School of Natural Sciences and Mathematics Ural Federal UniversityLenin Ave 51Ekaterinburg 620000Russia

Structural ordering in the concentrated magnetic colloids containing 50×5 nm hard magnetic disc-like SrFe_(12)O_(19) nanoparticles was investigated by cryogenic scanning electron microscopy,optical microscopy,magnetic measurements,and small-angle X-ray *** was revealed that macroscopically homogeneous magnetic liquid consists of dynamic threads of stacked *** threads align into quasiperiodic arrays with the distances between individual threads of a few *** also can form pseudodomain structures with -90°domain boundaries realized through T-type thread *** effects of magnetic attraction and electrostatic repulsion on the equilibrium interplatelet distance in the threads were *** was demonstrated that this distance can be tuned by the control of the particles charge and electric double layer screening from Stern layer thickness(-1 nm)to tens of *** was shown that the permanent magnetic field is not able to cause any structural changes in the ordered magnetic liquid phase,while alternating field draws particles apart by their *** variation of interparticle distance up to 6%was achieved using an alternating magnetic field of low *** data were complemented by the theoretical models of screened electrostatic interactions between spherical and platelike magnetic *** last model provides good predictive power and correlates with the experimental *** stabilization energy of the condensed phase in the order of 1-10 kBT was derived from the *** approach allows controlling of an equilibrium interparticle distance and interparticle distance distribution by adjusting the magnetization and surface charge of the particles as well as the ionic strength of the solvent.

关键词： hexaferrite ferrofluid self-assembly colloidal solution

NMR chemical shifts of carbon atoms and characteristic shift ranges in the oil sample

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Petroleum Research 2022年第2期7卷 269-274页

作者： Ilfat Z.Rakhmatullin Sergej v.Efimov Alexander v.Klochkov Oleg I.Gnezdilov Mikhail A.varfolomeev vladimir v.Klochkov Kazan Federal University 18 Kremlevskaya St.Kazan420008Russian Federation

Application of high resolution^(13)C nuclear magnetic resonance(NMR)spectroscopy to characterize crude oil was *** chemical shifts of^(13)C NMR functional groups that determine the composition of the oil sample were *** fractions of primary,secondary,quaternary,tertiary,aromatic groups,aromatic factor and average hydrocarbon chain length of aliphatic hydrocarbons of the oil sample according to^(13)C NMR spectra were *** description of the^(13)C NMR spectra of the oil sample using a single consideration of three NMR spectra:^(13)C,^(13)C Attached Proton Test(APT),^(13)C with Gated Decoupling(GD)was *** different contribution of the studied oil sample in the aliphatic(10e75 ppm)and aromatic(115e165 ppm)areas of the^(13)C NMR spectra was *** presence of all major hydrocarbon components in the studied oil sample was established on the quantitative level,the aromaticity factor and the mean length of the hydrocarbon chain were *** fractions of aromatic molecules and functional groups constituting oil hydrocarbons were *** this work we demonstrate that the attached proton test and gated decoupling^(13)C NMR spectroscopy can afford all information to complete the chemical shift assignment of an oil sample,especially for determination of long range 1He^(13)C coupling constants and^(13)C multiplicity.

关键词： ^(13)C NMR spectroscopy Crude oil Oil fraction Functional group Qualitative analysis Quantitative composition Aromaticity Attached proton test Gated decoupling

CaAl_(2)Si_(2)O_(8) polymorphs:Sensitive geothermometers and geospeedometers

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geoscience Frontiers 2023年第1期14卷 33-45页

作者： Liudmila A.Gorelova Oleg S.vereshchagin vladimir N.Bocharov Sergey v.Krivovichev Andrey A.Zolotarev Mikhail A.Rassomakhin Institute of Earth Sciences Saint Petersburg State UniversitySt.PetersburgRussia Centrefor Geo-Environmental Research and Modelling(Geomodel).Saint Petersburg State University St.PetersburgRussia Kola Science Centre ApatityMurmansk RegionRussia South Urals Federal Research Center of Mineralogy and Geoecology of UB RAS MiassRussia

Plagioclase is the major rock-forming mineral constituting the Earth's crust,whereas anorthite(CaAl_(2)Si_(2)O_(8))is a common minerals in lunar highlands crust,meteorites,possibly in some comets and on *** anorthite,two high-temperature polymorphs of CaAl_(2)Si_(2)O_(8)are known:dmisteinbergite and svyatoslavite,which are found in burnt coal dumps,meteorites and *** we present the results of detailed studies(quenching experiments,elemental analysis,Raman spectroscopy and in situ high temperature single crystal X-ray diffraction(up to 1000℃))on naturally co-occurring CaAl_(2)Si_(2)O_(8)polymorphs(anorthite,dmisteinbergite and svyatoslavite)from a burnt coal dump in Kopeisk,*** polymorphs were found in all natural samples and obtained upon heating of dmisteinbergite(unquenchableβ-dmisteinbergite and quenchable y-dmisteinbergite).It was shown that Ca coordination differs significantly in CaAl_(2)Si_(2)O_(8)polymorphs,resulting in a different capacity to host Ba and possibly other large ion lithophile *** our data on natural samples with the previously published data on natural and synthetic compounds,we propose a new scheme of CaAl_(2)Si_(2)O_(8)polymorphs *** results indicate that CaAl_(2)Si_(2)O_(8)polymorphs could be used for temperature estimations for both Earth and planetary sciences.

关键词： Feldspar Polymorphism Anorthite Dmisteinbergite Svyatoslavite CaAl_(2)Si_(2)O_(8)

Operating limits and features of direct air capture on K_(2)CO_(3)/ZrO_(2) composite sorbent

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2022年第6期35卷 11-20页

作者： vladimir S.Derevschikov Janna v.veselovskaya Anton S.Shalygin Dmitry A.Yatsenko Andrey Z.Sheshkovas Oleg N.Martyanov Boreskov Institute of Catalysis SB RAS Akademika Lavrentieva Av.5630090 NovosibirskRussia Novosibirsk State University Pirogova Str.1630090 NovosibirskRussia

Potassium carbonate-based sorbents are prospective materials for direct air capture(DAC).In the present study,we examined and revealed the influence of the temperature swing adsorption(TSA)cycle conditions on the CO_(2) sorption properties of a novel aerogel-based K_(2)CO_(3)/ZrO_(2) sorbent in a DAC *** was shown that the humidity and temperature drastically affect the sorption dynamic and sorption capacity of the *** a temperature at the sorption stage was 29℃ and a water vapor pressure P_(H2O) in the feed air was 5.2 mbar(1 bar=105 Pa),the composite material demonstrated a stable CO_(2) sorption capacity of 3.4%(mass).An increase in sorption temperature leads to a continuous decrease in the CO_(2) absorption capacity reaching a value of 0.7%(mass)at T=80℃.The material showed the retention of a stable CO_(2) sorption capacity for many cycles at each temperature in the *** PH2O in the inlet air from 5.2 to 6.8 mbar leads to instability of CO_(2) sorption capacity which decreases in the course of 3 consecutive TSA cycles from 1.7%to 0.8%(mass)at T=29℃.A further increase in air humidity only facilitates the deterioration of the CO_(2) sorption capacity of the material.A possible explanation for this phenomenon could be the filling of the porous system of the sorbent with solid reaction products and an aqueous solution of potassium salts,which leads to a significant slowdown in the CO_(2) diffusion in the composite sorbent *** investigate the regeneration step of the TSA cycle in situ,the macro ATRFTIR(attenuated total reflection Fourier-transform infrared)spectroscopic imaging was applied for the first *** was shown that the migration of carbonate-containing species over the surface of sorbent occurs during the thermal regeneration stage of the TSA *** movement of the active component in the porous matrix of the sorbent can affect the sorption characteristics of the composite *** revealed features make it possible

关键词： Zirconia aerogel Potassium carbonate Carbon dioxide Direct air capture Fourier-transform infrared spectroscopic imaging

Island Megalopolises： Tunnel Systems as a Critical Alternative in Solving Transport Problems

在线全文

学校读者我要写书评

暂无评论

Engineering 2018年第1期4卷 138-142页

作者： vladimir v. Makarov Far Eastern Federal University Vladivostok 690090 Russia

岛上大都市建设的一大关键困难是由有限的岛面用地导致的交通问题——公路及停车场地均需布置在已开发完成的岛上。这一限制便造成了公路数量稀少、路面交通拥堵、停车场地有限、车辆停放不规范等现象,容易引起安全事故。符拉迪沃斯托... 详细信息

岛上大都市建设的一大关键困难是由有限的岛面用地导致的交通问题——公路及停车场地均需布置在已开发完成的岛上。这一限制便造成了公路数量稀少、路面交通拥堵、停车场地有限、车辆停放不规范等现象,容易引起安全事故。符拉迪沃斯托克市位于俄罗斯远东地区穆拉维约夫-阿穆尔半岛(滨海边疆区)。该市因处在地缘政治要地,所以实际上也是俄罗斯的第三大首府。目前,为解决市内车辆交通问题,同时又考虑到缺少新建公路所需用地,当局就此提议应充分利用海岸沿线的海滩及滨水区域。不过,此项决定却与符拉迪沃斯托克市争创世界一流城市的生态及社会愿景存在明显冲突,且未能吸取世界其他海滨城市的经验教训——最初均在地面上修建了滨海公路,但之后又决定斥巨资拆除公路以合理享用滨海区的环境和历史资产。因此,建设一个独立的隧道交通系统及附加的地下停车场,似可作为解决交通问题的另一关键方案。此种方案的优点在于,它既能有效解决交通问题,又能改善该市的生态环境和宜居性。从解决交通问题的实际出发,在对两种方案进行比较后(即"地下"与"地面"的比较),可以看到独立的隧道系统具有多项主要优势。在比较中,我们提出了一套综合的效率评测标准,用以对符拉迪沃斯托克市交通系统方案的变量进行量化评估。经评估,地下方案比地面方案效率高出近1.8倍。

关键词： Megalopolises Transport Tunnels Efficiency Criteria

基于计算机辅助研究下的世界声乐艺术大师的颤音数据分析

在线全文

学校读者我要写书评

暂无评论

欧亚人文研究（中俄文） 2024年第2期 76-84,88,92页

作者： [俄]维·莫洛佐夫 [俄]彼·莫洛佐夫张喜梅(译) 俄罗斯科学院、柴可夫斯基音乐学院纽约科学院、俄罗斯国际创意学院俄罗斯科学院心理研究所中国传媒大学戏剧影视学院

颤音,是世界范围内相关学者、声乐艺术大师普遍公认的最重要的声乐演唱技术及声音美学特征。文章借助研究团队自主开发的测量歌唱颤音的方法及计算机分析检测程序,对世界各地55位知名声乐艺术大师的歌唱声音样本进行了针对性的提取、检... 详细信息

颤音,是世界范围内相关学者、声乐艺术大师普遍公认的最重要的声乐演唱技术及声音美学特征。文章借助研究团队自主开发的测量歌唱颤音的方法及计算机分析检测程序,对世界各地55位知名声乐艺术大师的歌唱声音样本进行了针对性的提取、检测与科学的统计分析,获得了世界男低音歌唱家夏里亚宾个人,及男女声6个演唱声部的颤音参数(7项)。研究表明,良好的颤音技术会提高和优化歌唱声音的飞跃性、穿透力、抗噪性和清晰度。且据初步数据显示,较同相颤音而言,反相颤音能赋予歌唱声音更高级的美学品质。

关键词：颤音歌唱声乐艺术大师数据分析

Effects of a Combined Silica-containing Additive on Structural and Rheological Properties of a Low-cement Silicon Carbide Castable

在线全文

学校读者我要写书评

暂无评论

China's Refractories 2022年第2期31卷 1-6页

作者： valeriy v.MARTYNENKO vladimir v.PRIMACHENKO Pavlo O.KUSHCHENKO Iri na G.SHULIK Ludmyla K.SAvINA The Ukrainian Research Institute of Refractories named after A.S.Berezhnoy Kharkiv 61024Ukraine

The use of a combined additive consisting of silica-containing additives“F”(thinning)and“S”(accelerating castable hardening)instead of the previously used silica-containing additive“A”and a mixture of dispersing additives based on polyethylene glycol in low-cement silicon carbide castable allows to improve the castable workability by increasing(in 5.4 times)the flowability of a freshly prepared castable,and increase by 1.2 and 1.1 times the cold crushing strength of heat-treated at temperatures of 110 and 1580°C,respectively,castable samples from low-cement silicon carbide castable with practically equal values of open porosity(15.8%and 16.0%).The petrographic studies of the castable sample microstructure after firing at a temperature of 1580°C showed that the investigated silica-containing additives“F”and“S”contribute to the denser and more uniform structure *** a result of the carried out research,the manufacturing technology of a low-cement silicon carbide castable was improved,of which the production was mastered at JSC“URIR named after ***”.

关键词： low-cement silicon carbide castable additives flowability structure strength

Study of native oil-bearing rocks of the Cuban basin by high resolution NMR spectroscopy

在线全文

学校读者我要写书评

暂无评论

Petroleum Research 2022年第4期7卷 495-499页

作者： Ilfat Z.Rakhmatullin Sergej v.Efimov Ekaterina I.Kondratyeva Lisset Miquel Gonzalez Kajum R.Safiullin Mikhail A.varfolomeev Alexander v.Klochkov vladimir v.Klochkov Kazan Federal University 18 Kremlevskaya St.Kazan420008Russian Federation

Application of high resolution^(13)C nuclear magnetic resonance(NMR)spectroscopy to characterize Cuba oil and oil-containing rock samples from Cuban basin was *** chemical shifts of^(13)C NMR functional groups for later determination the composition of the oil and rock samples were *** different contribution of the studied samples in the aliphatic and aromatic areas was *** fractions of primary,secondary,quaternary,tertiary,aromatic groups,aromaticity factor and the mean length of hydrocarbon chain length of aliphatic hydrocarbons were *** analysis on the quantitative level for all major hydrocarbon components,the aromaticity factor and the mean length of the hydrocarbon chain were carried out.

关键词： ^(13)C NMR spectroscopy Cuba oil Rock sample Functional group Qualitative analysis Quantitative composition Aromaticity

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

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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