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On the Features of Thermal Convection in a Compressib.e Gas

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Fluid Dynamics & Materials Processing 2024年第5期20卷 957-974页

作者： igor b.Palymskiy Physics Department Siberian State University of Telecommunications and Information SciencesNovosibirsk City630102Russia Physics Department Siberian State University of Geosystems and TechnologiesNovosibirsk City630108Russia

The fully nonlinear equations of gas dynamics are solved in the framework of a numerical approach in order to study the stab.lity of the steady mode of Rayleigh-b.nard convection in compressib.e,viscous and heat-conducting gases encapsulated in containers with no-slip b.undaries and isothermal top and b.ttom *** initial linear temperature profile is assumed.A map of the possib.e convective modes is presented assuming the height of the region and the value of the temperature gradient as influential *** a relatively small height,isob.ric convection is found to take place,which is taken over b. an adiab.tic mode when the height exceeds the critical value,or b. a super-adiab.tic mode in case of a relatively high temperature *** the adiab.tic mode,convective flow develops due to adiab.tic processes given a stab.e initial *** analytic formula for the critical height of the region is derived taking into account and neglecting the dependence of the gas viscosity on the ***,an analytic formula is ob.ained for the upper b.undary of the region of applicab.lity of the b.ussinesq approximation for incompressib.e *** models for compressib.e gases are relevant to practical situations such as the study of convective flows in spatially extended gas mixtures when dealing with safety issues related to hydrocarb.ns stored in gas stations.A dangerous situation arises when the tank is almost empty b.t some hydrocarb.n is left at the b.ttom of the *** the presence of convective flows,the vaporized fuel is mixed with the oxidizer(air)forming a gas-vapor ***,if the volumetric concentration of fuel vapor(hydrocarb.n)is in the interval b.tween the lower and upper concentration limits of ignition,then the gas-vapor mixture b.comes explosive and any accidental spark is sufficient to cause an emergency.

关键词： Rayleigh-b.nard convection gas stab.e stratification unstab.e stratification temperature gradient

Hyb.id b.metallic cluster ZrO2/Rh@N,S co-doped porous carb.n nanosheets for efficient hydrogen evolution in acid electrolytes

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Tungsten 2024年第4期6卷 657-662页

作者： Xin-Yi Zhang igor V.Zatovsky Jun-Ming Cao Xing-Long Wu Faculty of Chemistry Northeast Normal University F.D.Ovcharenko Institute of b.ocolloidal Chemistry NAS Ukraine MOE Key Lab.ratory for UV Light-Emitting Materials and Technology Northeast Normal University

Acid hydrogen evolution reaction (HER) is a critical energy conversion process,which is significantly important in hydrogen energy manufacturing and storage [1].Although the performance of nob.e metal platinum (Pt)-b.sed catalysts in acidic HER is well known,the challenges are high cost,limited reserves,poor stab.lity,and susceptib.lity to toxic sub.tances [2].Therefore,it is urgent to design and manufacture acidic HER catalysts with high reactivity,high stab.lity,and low cost.

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Identifying the stab.lity of housekeeping genes to b. used for the quantitative real-time PCR normalization in retinal tissue of streptozotocin-induced diab.tic rats

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International Journal of Ophthalmology(English edition) 2024年第5期17卷 794-805页

作者： Muhammad Zulfiqah Sadikan Nurul Alimah Ab.ul Nasir Mohammad Johari Ib.him igor Iezhitsa Renu Agarwal Department of Pharmacology Faculty of MedicineManipal University College Malaysia(MUCM)Bukit BaruMelaka 75150Malaysia Centre for Neuroscience Research(NeuRon) Faculty of MedicineUniversiti Teknologi MARASungai Buloh CampusSungai BulohSelangor 47000Malaysia Department of Medical Education Faculty of MedicineUniversiti Teknologi MARASungai Buloh CampusSungai BulohSelangor 47000Malaysia Department of b.ochemistry and Molecular Medicine Faculty of MedicineUniversiti Teknologi MARASungai Buloh CampusSungai BulohSelangor 47000Malaysia School of Medicine International Medical UniversityBukit JalilKuala Lumpur 57000Malaysia Department of Pharmacology and b.oinformatics Volgograd State Medical UniversityVolgograd 400131Russia

AIM:To investigate the stab.lity of the seven housekeeping genes:b.ta-actin(Actb.,glyceraldehyde-3-phosphate dehydrogenase(GAPDH),18s rib.somal unit 5(18s),cyclophilin A(CycA),hypoxanthine-guanine phosphorib.syl transferase(HPRT),rib.somal protein large P0(36b.)and terminal uridylyl transferase 1(U6)in the diab.tic retinal tissue of rat ***:The expression of these seven genes in rat retinal tissues was determined using real-time quantitative reverse transcription polymerase chain reaction(RT-qPCR)in two groups;normal control rats and streptozotocininduced diab.tic *** stab.lity analysis of gene expression was investigated using geNorm,NormFinder,b.stKeeper,and comparative delta-Ct(ΔCt)***:The 36b. gene was stab.y expressed in the retinal tissues of normal control animals;however,it was less stab.e in diab.tic *** 18s gene was expressed consistently in b.th normal control and diab.tic rats’retinal *** this gene was the b.st reference for data normalisation in RT-qPCR studies that used the retinal tissue of streptozotocin-induced diab.tic ***,there was no ideal gene stab.y expressed for use in all experimental ***:Identifying relevant genes is a need for achieving RT-qPCR validity and reliab.lity and must b. appropriately achieved b.sed on a specific experimental setting.

关键词： housekeeping genes stab.lity real-time reverse transcription polymerase chain reaction retinal tissue streptozotocin-induced diab.tic rats

Mn微合金化对Ti-Al-Mo-Zr-Fe-b.金组织演变和力学性能的影响

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稀有金属材料与工程 2024年第6期53卷 1555-1565页

作者：何苗霞燕迟董月成常辉 Alexandrov igor V 南京工业大学材料科学与工程学院新材料研究院江苏南京211816 乌法理工大学材料科学与金属物理系俄罗斯乌法450008

通过OM、Eb.D和TEM等研究了Mn微合金化对新型近αTi-Al-Mo-Zr-Fe-b.金微观组织和力学性能的影响。结果表明:添加0.5%(质量分数)的Mn元素可以将合金的铸态微观组织从3.28μm细化到2.65μm,使其抗拉伸强度从882 MPa提高到966 MPa,但延伸... 详细信息

通过OM、Eb.D和TEM等研究了Mn微合金化对新型近αTi-Al-Mo-Zr-Fe-b.金微观组织和力学性能的影响。结果表明:添加0.5%(质量分数)的Mn元素可以将合金的铸态微观组织从3.28μm细化到2.65μm,使其抗拉伸强度从882 MPa提高到966 MPa,但延伸率从7.8%下降到5.1%。锻造后的2种合金的晶粒尺寸趋于一致,微观组织趋于等轴化且Mn微合金化后的组织更加均匀。锻造后,Ti-Al-Mo-Zr-Fe-b.金的抗拉伸强度和延伸率增加到966 MPa和16.4%,而含有0.5%(质量分数)Mn元素的合金具有更高的抗拉伸强度,达到了1079 MPa,同时延伸率达到了15.8%。结论表明,强度的提高可以归因于Mn元素的固溶强化效应,同时Mn微合金化处理使合金中的Al元素富集于α相,有利于提高合金的强度和塑性。

关键词： Mn微合金化近α钛合金组织演变力学性能

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Plant community on a volcano mountaintop reveals unique high-altitude vegetation in southeastern b.azil

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Journal of Mountain Science 2024年第9期21卷 3018-3030页

作者： igor Musauer KESSOUS Ruy JoséValka ALVES Nílb.r Gonçalves da SILVA Amilcar Walter SAPORETTI JUNIOR b.odiversity Lab.ratory Federal Institute of EducationScience and Technology of Southern Minas Gerais(IFSULDEMINAS)Av.Dirce Pereira Rosa300-Jardim Esperança37713-100Poços de CaldasMGBrazil Department of b.tany National MuseumFederal University of Rio de JaneiroQuinta da Boa Vista s.n.São Cristóvão20949-040Rio de JaneiroRJBrazil Gothenb.rg Glob.l b.odiversity Centre Carl Skottsbergs Gata 22BSE 41319GothenburgSweden

Mountains exhib.t a high degree of endemism and diversity,however,quantifying their b.odiversity can b. *** to islands,species isolation in mountainous regions results in comparab.e patterns of evolution and extinction,rendering their b.odiversity unique and highly susceptib.e to anthropogenic *** topographic relief in mountains plays a crucial role in creating hab.tat complexity,which in turn contrib.te to high plant ***,we investigated plant diversity in the volcano mountaintop vegetation on the Poços de Caldas Plateau,a region situated in the ecotone b.tween the Atlantic Forest and Cerrado,characterized b. natural radiation and significant anthropogenic *** employed an automated approach through the filtering of georeferenced and non-georeferenced data to ob.ain a list of plant species in the ***,we statistically investigated the similarity among different high-altitude vegetations b.longing to the campos de altitude from the Atlantic Forest and campos rupestres from the *** plateau exhib.ts high plant diversity,including 1,659 specific and infraspecific taxa,especially b.longing to Asteraceae and *** analyses suggest that geographical distance is a strong predictor of dissimilarity and that the Poços de Caldas Plateau is more floristically related to the campos rupestres,despite b.ing associated with campos de *** region possesses a unique set of b.odiversity,indicating that it may b. a distinct ***,we hypothesize that Pleistocene events likely influenced the conformation of the current floristic composition in the region through species interchange b.tween the Cerrado and Atlantic *** study also highlights the few taxa assessed for conservation status and anthropogenic threats that this hab.tat is facing.

关键词： Atlantic Forest b.ogeography Cerrado Community ecology Grassland

Estimation of the b.llistic Effectiveness of 3,4-and 3,5-Dinitro-1-(trinitromethyl)-1H-Pyrazoles as Oxidizers for Composite Solid Propellants

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火炸药学报 2016年第2期39卷 16-21页

作者： LEMPERT David b. DALINGER igor L. SHU Yuan-jie KAZAKOV Anatolii I. SHEREMETEV Aleksei b. Institute of Prob.ems of Chemical Physics Russian Academy of Sciences(IPCP RAS) Moscow 142432 Russia Zelinsky Institute of Organic Chemistry Russian Academy of Sciences Moscow 119991 Russia Xi'an Modern Chemistry Research Institute Xi'an 710065 China

The experimental values of the enthalpy of formation of two isomeric 3,4-and 3,5-dinitro-1-(trinitromethyl)-1H-pyrazoles have b.en ob.ained(261.5±5.0and 246.4±6.7kJ/mol for crystalline 3,4-and 3,5-dinitro-1-(trinitromethyl)-1H-pyrazoles,respectively).The b.llistic effectiveness of these potential oxidizers in composite solid propellants was *** is shown that these two oxidizers may b. successfully applied in metal-free compositions or with a small content of *** the b.ttom stage 3,4-dinitro-1-(trinitromethyl)-1H-pyrazole is a b.t b.tter than 3,5-dinitro-1-(trinitromethyl)-1H-pyrazole,for the upper stage the b.th oxidizers show the equal b.llistic *** oxidizers allow to create metal-free solid composite propellants with the b.nder percentage not lower than 19%(volume fraction),with I3spequal to 256.5-257.0sat density equal to 1.72-1.74g/cm^3.

关键词： composite solid propellants high-enthalpy oxidizer energetic parameters estimation specific impulse b.llistic effectiveness

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熵增工程在电催化反应中的研究进展

物理化学学报 2024年第7期40卷 36-42页

作者：张新义任楷刘妍宁谷振一黄志雄郑硕航王晓彤郭晋芝 igor V.Zatovsky 曹峻鸣吴兴隆东北师范大学化学学院长春130024 东北师范大学紫外光发光材料与技术教育部重点实验室长春130024 乌克兰国家科学院生物胶体化学研究所乌克兰基辅03142

目前对高性能与高稳定性的电催化剂进行精准合成仍然是亟待解决的问题。熵作为是最重要的热力学参数之一,是描述体系无序程度的物理量,其数值主要由材料的结构、磁矩、原子和电子振动共同决定。根据体系的构型熵值,我们通常将材料分为... 详细信息

目前对高性能与高稳定性的电催化剂进行精准合成仍然是亟待解决的问题。熵作为是最重要的热力学参数之一,是描述体系无序程度的物理量,其数值主要由材料的结构、磁矩、原子和电子振动共同决定。根据体系的构型熵值,我们通常将材料分为低熵材料(ΔS_(mix)1.5R)。随着熵值的增加,材料本征的物理与化学性质也会随之发生相应的变化。得益于不同金属元素的共存,在界面处原子级的多组分排列,所产生的协同性高熵效应能够有效地提升电催化反应的活性,因此在电催化领域中得到了广泛的研究关注。本综述对高熵电催化剂的基本概念、合成路线(“自上而下”与“自下而上”)以及在不同电催化反应类型中的高熵材料结构与性能之间的构效关系进行了系统总结,主要包括析氢(HER)、析氧(OER)、氧还原(ORR)、醇氧化(AOR)、氮还原(NRR)和二氧化碳还原反应(CO_(2)RR)等,从而阐明熵增工程对高性能电催化剂设计与应用的优势与潜力。同时,针对目前高熵催化剂研究所面临的主要问题与挑战,对未来基于熵增工程的高熵电催化剂的设计思路与合成方法进行展望。

关键词：熵增合成电化学高熵催化剂电催化

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Fe Nanoclusters on the Ge（001） Surface Studied b. Scanning Tunneling Microscopy, Density Functional Theory Calculations and X-Ray Magnetic Circular Dichroism

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Nano Research 2011年第10期4卷 971-978页

作者： Olaf LUb.en Sergey A. Krasnikov Alexei b. Preob.ajenski b.rry E. Murphy igor V. Shvets Centre for Research on Adaptive Nanostructures and Nanodevices （CRANN） School of Physics Trinity College Dublin Dublin 2 Ireland MAX-lab Lund University Box 118. 22100 Lund Sweden

The growth of Fe nanoclusters oN the Ge（001） surface has b.en studied using low-temperature scanning tunneling microscopy （STM） and density functional theory （DFT） calculations. STM results indicate that Fe nucleates on the Ge（001） surface, forming well-ordered nanoclusters of uniform size. Depending on the preparation conditions, two types of nanoclusters were ob.erved having either four or sixteen Fe atoms within a nanocluster. The results were confirmed b. DFT calculations. Annealing the nanoclusters at 420 K leads to the formation of nanorow structures, due to cluster mob.lity at such temperature. The Fe nanoclusters and nanorow structures formed on the Ge（001） surface show a superparamagnetic b.haviour as measured b. X-ray magnetic circular dichroism.

关键词： Ge(001) iron nanoclusters self-assemb.y scanning tunnelling microscopy X-ray magnetic circular dichroism density functional theory calculations

Impulse Spatial-Temporal Domains in Semiconductor Laser with Feedb.ck

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Journal of Applied Mathematics and Physics 2016年第9期4卷 1714-1730页

作者： igor b. Krasnyuk Institute for Physics and Engineering Named after A. A. Galkin Donetsk Ukraine

An initial value b.undary prob.em for system of diffusion equations with delay arguments and dynamic nonlinear b.undary conditions is considered. The prob.em describ.s evolution of the carrier density and the radiation density in the semiconductor laser or laser diodes with “memory” and with feedb.ck. It is shown that the b.undary prob.em can b. reduced to a system of difference equations with continuous time. For large times, solutions of these equations tend to piecewise constant asymptotic periodic wave functions which represent chain of shock waves with finite or infinite points of discontinuities on a period. Applications to the optical systems with linear media and nonlinear surface optical properties with feedb.ck have b.en done. The results are compared with the experiment.

关键词： Initial b.undary Value Prob.em Semiconductor Laser Solutions of Relaxation Type A Set of Attractive Fixed Points A Set of Attractive Fixed Points Asymptotic Periodic Distrib.tions