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Synthesis of Al2O3-SiO2-MgO ceramics with hierarchical porous structure

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Journal of Advanced Ceramics 2017年第1期6卷 92-页

作者： Elena F.KRIvOSHAPKINA Pavel v.KRIvOSHAPKIN aleksey A.vEDYAGIN Institute of Chemistry of Komi SC UB RAS Syktyvkar 167982 Russia ITMO University St.Petersburg 197101 Russia Boreskov Institute of Catalysis SB RAS Novosibirsk 630090 Russia National Research Tomsk Polytechnic University Tomsk 634050 Russia

A series of asymmetric cordierite ceramics with hierarchical porous structure were prepared and *** macroporous support was obtained from natural raw materials (bauxite,silica sand,kaolinite,talc,and alumina) via ceramic *** prepared ceramic discs were characterized by a narrow pore size *** average pore size was about 9.5 μm,and the open porosity was estimated to be 30％.Coating the discs with micro/mesoporous cordierite layer was performed using the sol-gel ***-component sols were obtained from organic or inorganic *** gels were calcined at 1200 ℃ to form the cordierite *** nature of precursor was found to affect the pore volume *** pore volume distribution was observed when organic precursors were *** key factor to control the parameters of final material was the drying *** drying of the gels has allowed us to increase the surface area in two orders of magnitude comparing with conventional drying procedure.

关键词： sol-gel method aerogels cordierite Al2O3-SiO2-MgO hierarchical porous structure

Genes associated with testicular germ cell tumors and testicular dysgenesis in patients with testicular microlithiasis

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Asian Journal of Andrology 2018年第6期20卷 593-599页

作者： Ilya S Dantsev Evgeniy v Ivkin aleksey A Tryakin Dmitriy N Godlevski Oleg Yu Latyshev victoriya v Rudenko Dmitry S Mikhaylenko vyacheslav B Chernykh Elena A volodko aleksey B Okulov Oleg B Loran Marina v Nemtsova Russian Medical Academy ef Postgraduate Education Moscow 123995Russia N.N.Blokhin Russian Cancer Research Center Moscow 115478Russia Research Centre of Medical Genetics Moscow 115478Russia M.Sechenov First Moscow State Medical University Moscow 119991Russia N.I.Pirogov Russian National Research Medical University Moscow 117997Russia.

Testicular microlithiasis （TM） is one of the symptoms of testicular dysgenesis syndrome （TDS）. TM is particularly interesting as an informative marker of testicular germ cell tumors （TGCTs）. KIT ligand gene （KITLG）, BCL2 antagonist/killer 1 （BAK1）, and sprouty RTK signaling antagonist 4 （SPRY4） genes are associated with a high risk of TGCTs, whereas bone morphogenetic protein 7 gene （BMP7）, transforming growth factor beta receptor 3 gene （TGFBR3）, and homeobox D cluster genes （HOXD） are related to TDS. Using polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP） analysis, we investigated allele and genotype frequencies for KITLG （rs995030, rs1508595）, SPRY4 （rs4624820, rs6897876）, BAK1 （rs210138）, BMP7 （rs388286）, TGFBR3 （rs12082710）, and HOXD （rs17198432） in 142 TGCT patients, 137 TM patients, and 153 fertile men （control group）. We found significant differences in the KITLG GG_rs995030 genotype in TM （P= 0.01） and TGCT patients （P = 0.0005） compared with the control. We also revealed strong associations between KITLGrs1508595 and TM （G allele, P = 0.003; GG genotype, P= 0.01） and between KITLG_rs1508595 and TGCTs （G allele, P-- 0.0001; GG genotype, P = 0.0007）. Moreover, there was a significant difference in BMP7_rs388286 between the TGCT group and the control （T allele, P = 0.00004; TT genotype, P = 0.00006） and between the TM group and the control （T allele, P= 0.04）. HOXDalso demonstrated a strong association with TGCTs （rs17198432 A allele, P = 0.0001; AA genotype, P = 0.001）. Furthermore, significant differences were found between the TGCT group and the control in the BAK1_rs210138 G allele （P= 0.03） and the GG genotype （P= 0.01）. KITLG and BMP7genes, associated with the development of TGCTs, may also be related to TM. In summary, the KITLG GG_rs995030, GG_rs1508595, BMP7 TT_rs388286, HOXD AA_rs17198432, and BAK1 GG_rs210138 genotypes were associated with a high risk of TGCT development.

关键词： associations genotype high risk testicular dysgenesis syndrome testicular microlithiasis

Electro–optic response in thin smectic C* film with chevron structures

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Chinese Physics B 2016年第12期25卷 337-343页

作者： aleksey A Kudreyko Nail G Migranov Dana N Migranova Ufa State Petroleum Technological University Department of Physics Bashkir State Pedagogical University Department of General and Theoretical Physics

The effects in electrostatic models of chevron surface-stabilized ferroelectric liquid crystals are investigated through numerical modeling. To study smectic C＊ director distribution within the cell, we consider two nonlinear approaches： the chevron interface does not interplay with the electric field; the electric field interplays with the chevron interface. The obtained results of the director field distribution are compared with the earlier linearized studies. We find that whether or not the electric field interplays with the chevron interface, the electro-optic response requires a generalized approach for its description. The threshold electric field, which is necessary for switching between two stable director states in the chevron cell is evaluated. This study suggests that, in many cases of practical interest, electro-optic response to the electric field and the threshold electric field can be precisely estimated. We argue that, beside being numerically efficient, our approach provides a convenient and a novel standpoint for looking at the electro-optic response problem.

关键词： surface-stabilized ferroelectric liquid crystal chevron structure thin films bistability Euler'sequation

Considering temperature dependence of thermo-physical properties of sandy soils in two scenarios of oil pollution

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Research in Cold and Arid Regions 2014年第4期6卷 302-308页

作者： aleksey v.Malyshev Anatoly M.Timofeev Institute of Physical-Technical Problems of the North. v.P. Larionov Siberian Branch of the Russian Academy of Sciences

We analyzed the heat conductivity and volumetric heat capacity of sandy soil contaminated in two scenarios of oil pollution, and also determined the temperature dependencies of these changed thermophysical properties. In the first pollution scenario, the oil product was introduced into wet river sand, and in the second case, dry sand was contaminated by the oil product and was then moistened with water. By considering these two scenarios as multicomponent dispersion systems with varying degrees of contamination and humidity, and by using a polystructural granular model with pore spaces and closed inclusions, we calculated that the heat conductivity of the sandy soil increased under the first pollution scenario and decreased under the second, but the change in the volumetric heat capacity of the sandy soil was proportional only to the amount of oil pollution, not the manner in which it was introduced. We also determined the temperature dependencies of these two thermophysical properties of sandy soil when polluted by oil, of which information will be useful for future containment and remediation of oil-contaminated soil.

关键词： sandy soil heat conductivity heat capacity heat resistance pollution oil product unfrozen water volumeconcentration coordination number

Highly Heat-Resistant Materials for Microelectronics:Hydrodynamic,Optical,and Conformational Properties of Fluorine Containing Poly(Amido-ortho-Hydroxy Amide)

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Journal of Wuhan University of Technology(Materials Science) 2020年第1期35卷 223-230页

作者： Irina A Strelina Liudmila I Rudaya Ol’ga v Okatova Maxim N Bol’shakov aleksey YuMarfichev Galina K Lebedeva Yuliya v Shagayko Stanislav M Ramsh Institute of Macromolecular Compounds Russian Academy of SciencesBolshoi pr.VO 31St Petersburg199004 Russia Saint-Petersburg State Institute of Technology(Technical University) Moskovskii pr.26St Petersburg190013 Russia

The polycondensation of the mixture of diamines 5,5-methylene bis(2-aminophenol) and 4,4-(hexafluoroisopropylidene)dianiline(molar ratio 0.8:0.2) with isophthaloyl dichloride was used to synthesize poly(amido-o-hydroxy amide)(POA-F)-new heat resistant binder of the composites for microelectronics. The copolymer was fractionated, its hydrodynamic, optical, and conformational properties were researched, and molecular masses(ММ) of the fractions were defined. The polydispersity index was estimated. Based on experimental data, calculation of the size of a segment of Kuhn characterizing degree of an intramolecular orientation order and value of coefficients of the equation of Mark-Kuhn-Hauvink for viscometric and diffusion data were performed. It was demonstrated that introducing 20 mol % of the monomer with-CF3-groups does not lead to any changes in conformational properties of the macromolecules and does not change the degree of intramolecular orientational order(the Kuhn segment length). Optical characteristics of POA-F solutions are virtually similar to the corresponding values for POA prepared with the use of single amine-containing component-5,5-methylene bis(2-aminophenol). The received MM distribution for POA-F(prepolymer) provided the solubility of its films in alkaline solutions. The heat resistance(τ5 and τ10-temperatures corresponding to 5% and of 10% PBO-F mass loss of a polymer) of the powders and the films of PBO, PBO-F were determined. The electrophysical parameters-dielectric permittivity(ε) and dielectric loss tangent(tan δ) of the PBO-F films decreased down to 3.30 and 0.017, in comparison 3.40 and 0.025 for PBO respectively.

关键词： poly(o-hydroxy amide) 4,4-(hexafluoroisopropylidene) dianiline Kuhn segment Mark-Kuhn-Houwink equations translational diffusion intrinsic viscosity flow birefringence

Design of broadband terahertz vector and vortex beams: II. Holographic assessment

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Light(Advanced Manufacturing) 2022年第4期3卷 14-26页

作者： Nikolay v.Petrov Bogdan Sokolenko Maksim S.Kulya Andrei Gorodetsky aleksey v.Chernykh Digital and Display Holography Laboratory ITMO UniversitySt.Petersburg 197101Russia v.I.vernadsky Crimean Federal University Simferopol 295007Russia School of Physics and Astronomy University of BirminghamBirmingham B152TTUK

In this paper,we demonstrate the capabilities of the terahertz pulse time-domain holography in visualisation,simulation,and assessment of broadband THz vortex beam formation dynamics upon its shaping by elements of beam converter,and further propagation and *** adding Jones matrix formalism to describe broadband optical elements,we highlight the differences in the spatio-spectral and spatio-temporal structure of the formed vortex and vector beams dependence on the modulator used and visualise their modal *** influence of diffraction field structure from each element in the broadband vortex modulator is revealed in numerical simulation and the formed beams are analysed against the simplified Laguerre-Gaussian beam model.

关键词： Terahertz radiation vortex beams vector beams Achromatic wave plates Broadband terahertz radiation Digital holography Terahertz holography

Design of broadband terahertz vector and vortex beams: I. Review of materials and components

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Light(Advanced Manufacturing) 2022年第4期3卷 126-144页

In this paper,we review the existing approaches for vortex and vector beam shaping and generation in the terahertz frequency *** particular focus of this review is on the possibility of homogeneous topological charge formation in the ultra-wide spectral interval inherent to ultrashort terahertz *** review the available materials and components,analyse proposed and potentially possible solutions for broadband terahertz vortex and vector beam shaping,compare all developed approaches,and put forward a unified concept for constructing passive shapers of such beams from the existing component base.

关键词： Terahertz radiation vortex beams vector beams Achromatic wave plates Broadband terahertz radiation Digital holography Terahertz holography Total internal reflection Metasurface THz liquid crystals Geometric phase

Effects of site preparation methods on soil physical properties and outplanting success of coniferous seedlings in boreal forests

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Journal of Forestry Research 2024年第2期35卷 70-80页

作者： aleksey S.Ilintsev Elena N.Nakvasina Alexander P.Bogdanov Northern Research Institute of Forestry 13 Nikitova Str.Arkhangelsk 163062Russian Federation Department of Silviculture and Forest Management Northern(Arctic)Federal University Named After M.V.LomonosovSevernoy Dviny Emb.17Arkhangelsk 163002Russian Federation

This study assessed the effect of patch scarification and mounding on the physical properties of the root layer and the success of tree planting in various types of *** study was conducted on 12 forest sites in taiga forests of the European part of Russia.A total of 54 plots were set up to assess seedling survival;root collar diameter,height,and heigh increment were measured for 240 seedlings to assess *** the rooting layer,240 soil samples were taken to determine physical *** study showed that soil treatment methods had no effect on bulk density and total porosity in Cladina ***,reduced soil moisture was noted,particularly in mounds,resulting in increased *** Myrtillus sites,there were increased bulk density,reduced soil moisture,and total porosity in the *** treatment in Polytrichum sites resulted in reduced soil moisture and increased aeration *** the Myrtillus and Polytrichum sites,patch scarification had no effects on physical *** Polytrichum sites,survival rates,heights,and heigh increments of bareroot Norway spruce seedlings in mounds were higher than in patches;however,the same did not apply to *** Cladina and Myrtillus sites,there was no difference in growth for bareroot and containerised seedlings with different soil *** conditions and soil types should be considered when applying different soil treatment methods to ensure high survival rates and successful seedling growth.

关键词： Boreal forests Mechanical site preparation Patch scarification Mounding Soil properties Containerised seedlings Bareroot seedlings

Postglacial incision-infill cycles at the Borisoglebsk Upland: Correlations between interfluve headwaters and fluvial network

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International Soil and Water Conservation Research 2019年第2期7卷 184-195页

作者： Yuliya v.Shishkina Ekaterina v.Garankina vladimir R.Belyaev Ilya G.Shorkunov Pavel v.Andreev aleksey I.Bondar viktoria I.Potapova Tatiana A.verlova Faculty of Geography Department of Geomorphology and Palaeogeography and Laboratory for Soil Erosion and Fluvial ProcessesLomonosov Moscow State UniversityLeninskie Gory1Moscow 119991Russia Institute of Geography Department of Soil Geography and EvolutionRussian Academy of SciencesStaromonetnyj Lane29Moscow 119017Russia Institute of Earth Sciences of Saint-Petersburg State University St.PetersburgUniversitetskaya nab.7-9 199034Russia

The article discusses postglacial landscape transformation in the Northern Hemisphere Middle Pleistocene glaciation area located in the center of the Russian *** attempted to verify the regional paleogeographic model by reconstructing the Late Pleistocene incision-infill cycles at the Eastern Borisoglebsk Upland based on a comparison of inactive interfluves headwaters and actual fluvial network *** study was also aimed to determine the past extent of fluvial *** research of the actual and buried topography,Ethology and pedogenic properties of surface deposits was carrid out with remote sensing data interpretation,DGPS survey,and detailed description of geological cores *** study was followed by analysis of grain size,chemical and organic contents,microstructure,and numerical *** the available results,we propose a scenario of the fluvial network transformation at the Eastem Borisoglebsk Upland over the last 150 *** least four fluvial incision stages were determined while network extent has significantly changed through the Late *** can be generally associated with the regional base level decrease-Late Moscow,Late valdai and Late Holocene and accompanying isolation of the Nero Lake terraces of 130 m,100-105 m and 95-98 *** stages were separated by landscape stability or aggradation periods those were asynchronous at the middle and upper parts of the fluvial *** main agent of initial valley infill appears to be local lacustrine sedimentation altered by alluvial and colluvial deposition towards the second half of *** landscape conditions variability emphasize the importance of comprehensive local correlations for regional retrospective models.

关键词： Interfluve headwaters Fluvial Incision-Infill Cycle Pleistocene