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Wood anatomy chronologies of Scots pine in the foothills of the Western Sayan(Siberia)

Journal of Forestry Research 2024年第3期35卷 13-27页

作者： Elena A.Babushkina Dmitry R.Dergunov Mikhail S.Zharkov Liliana V.Belokopytova Dina F.Zhirnova Bao Yang Jingjing Liu Xiaomei Peng Eugene A.Vaganov Khakass Technical Institute Siberian Federal UniversityAbakan 655017Russia Institute of Ecology and Geography Siberian Federal UniversityKrasnoyarsk 660036Russia Mathematical Methods and IT Department Siberian Federal UniversityKrasnoyarsk 660036Russia Key Laboratory of Desert and Desertification Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000People's Republic of China School of Geographic and Oceanographic sciences Nanjing UniversityNanjing 210093People's Republic of China Department of Dendroecology V.N.Sukachev Institute of ForestSiberian Branch of the Russian Academy of ScienceKrasnoyarsk 660036Russia

Recent methodological advances in quantitative wood anatomy have provided new insights into the climatic responses of radial growth at the scale of cell structure of tree rings. This study considered long-term chronologies of tracheid measurements, indexed by a novel approach to separate their specific climatic responses from signal recorded in cell production(closely reflected in tree-ring width). To fill gaps in understanding the impact of climate on conifer xylem structure, Scots pine(Pinus sylvestris L.)trees > 200 years old were selected within the forest-steppe zone in southern Siberia. Such habitats undergo mild moisture deficits and the resulting climatic regulation of growth processes. Mean and maximum values of cell radial diameter and cell wall thickness were recorded for each tree *** a low level of climatogenic stress, components of cell chronologies independent of cambial activity were separated to obtain significant climatic signals revealing the timing of the specific stages of tracheid differentiation. Cell expansion lasted from mid-April to July and was impacted similarly to tree-ring width(stimulated by precipitation and stressed by heat), maximum cell size formed late June. A switch in the climatic responses of mean anatomical traits indicated transition to latewood in mid-July. Secondary wall deposition lasted until mid-September, suppressed by end of season temperatures. Generally, anatomical climatic responses were modulated by a less dry May and September compared with summer months.

关键词： Quantitative wood anatomy Cell radial size Cell wall thickness Pinus sylvestris Climatic response

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Efficient cold atom source from a single-layer atom chip

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Chinese Optics Letters 2024年第6期22卷 103-108页

作者： Petr Skakunenko Darya Bykova Anton Afanasiev Alexey Kalmykov Roman Kirtaev Victor Balykin Institute of Spectroscopy russian Academy of sciences Moscow 108840Russia Moscow Institute of Physics and Technology Moscow 141700Russia Skolkovo Institute of science and Technology Moscow 121205Russia National Research University Higher School of Economics Moscow 101000Russia Present affiliation:Emerging Technologies Research Center XPANCEODubaiUnited Arab Emirates

We developed a new single-layer atom chip with an additional U-shaped current-carrying *** new U-shaped microwire creates optimized magnetic field distribution,which increases the trapping volume of a magneto-optical trap(MOT) near the *** approach allows one to localize more atoms,while a setup remains relatively simple (single-layer approach) and consumes low current (up to 10 A). The total number of trapped~(87)Rb atoms in our setup is 5×10~7.

关键词： atom chip cold atoms laser cooling magneto-optical trap U-MOT

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Predicting impact strength of perforated targets using artificial neural networks trained on FEM-generated datasets

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Defence Technology（防务技术） 2024年第2期32卷 32-44页

作者： Nikita Kazarinov Aleksandr Khvorov Saint Petersburg State University Saint Petersburg 199034Russia Higher School of Economics Saint Petersburg 190121Russia

The paper considers application of artificial neural networks(ANNs)for fast numerical evaluation of a residual impactor velocity for a family of perforated PMMA(Polymethylmethacrylate)*** ANN models were trained using sets of numerical results on impact of PMMA plates obtained via dynamic FEM coupled with incubation time fracture *** developed approach makes it possible to evaluate the impact strength of a particular target configuration without complicated FEM calculations which require considerable computational ***,it is shown that the ANN models are able to predict results for the configurations which cannot be processed using the developed FEM routine due to numerical instabilities and errors:the trained neural network uses information from successful computations to obtain results for the problematic cases.A simple static problem of a perforated plate deformation is discussed prior to the impact problem and preferable ANN architectures are presented for both *** insight into the perforation pattern optimization using a genetic algorithm coupled with the ANN is also made and optimized perforation patterns which theoretically enhance the target impact strength are constructed.

关键词： Machine learning Impact Dynamic fracture FEM Mesh distortion Optimization

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Analysis of the discrete contact characteristics based on the Greenwood-Williamson model and the localization principle

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Friction 2024年第5期12卷 1042-1056页

作者： Anastasiya A.YAKOVENKO Irina G.GORYACHEVA Ishlinsky Institute for Problems in Mechanics RAS Moscow119526Russia

The contact of a rigid body with nominally flat rough surface and an elastic half-space is *** solve the contact problem,the Greenwood-Williamson statistical model and the localization principle are *** developed contact model allows us to investigate the surface approach and the real contact area with taking into account the asperities *** is shown that the mutual influence of asperities changes not only contact characteristics at the macroscale,but also the contact pressure distribution at the *** follows from the results,the inclusion in the contact model of the effect of the mutual influence of asperities is especially significant for studying the real contact area,as well as the contact characteristics at high applied *** results calculated according to the proposed approach are in a good agreement with the experimentally observed effects,i.e.,the real contact area saturation and the additional compliance exhaustion.

关键词： surface roughness elasticity Greenwood-Williamson model localization principle asperity interaction

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Thermo-and pH-sensitive Polymer with Pendant Spacer-linked Imidazole Cycles

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Chinese Journal of Polymer science 2024年第4期42卷 437-445页

作者： Natalya V.Zakharova Stanislav N.Zelinskiy Mariya S.Strelova Elena N.Danilovtseva Vadim V.Annenkov Institute of Macromolecular Compounds of the russian Academy of sciences Saint Petersburg199004Russia Limnological Institute of Siberian Branch of the russian Academy of sciences Irkutsk664033Russia

By the reaction of poly(acryloyl chloride) with N-(3-aminopropyl)imidazole, poly(N-(3-(1H-imidazol-1-yl)propyl)acrylamide) was synthesized. The new polymer contains an imidazole ring removed from the main chain by a spacer of five bonds. The structure and purity, molecular weight, hydrodynamic and thermosensitive properties of the obtained sample were studied by1H-and13C-NMR, FTIR spectroscopy, acid-base titration, light scattering, turbidimetry and viscometry. The observed ability of the imidazole-containing polymer to form and destroy associates in water-salt solutions at pH 6.6-7.4 and temperatures of 29-48℃ indicates that these are promising candidates for designing complex biomedical systems. The new polymer is able to form complexes with oligo-DNA more actively than poly(1-vinylimidazole), which is of interest for gene delivery applications. The polymer cross-linked with epichlorohydrin gives micro-relief coatings on the plastic surface, and the modified surface is able to attach negatively charged objects. This thermo-and pH-sensitive polymer modification can be applied to create finely controlled surfaces for cell culturing.

关键词： Imidazole-containing polymer Thermolability pH-sensitivity The modified surface DNA immobilization

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Photoluminescence,structural and antibacterial properties of co-dopedβ-Ca_(3)(PO_(4))_(2)-type phosphates Ca_(8)CuRE(PO_(4))_(7)(RE=Eu-Er)

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Journal of Rare Earths 2024年第9期42卷 1658-1668,I0002页

作者： Ivan V.Nikiforov Ekaterina V.Iliin Bogdan I.Lazoryak Sergey M.Aksenov Pavel V.Slukin Dina V.Deyneko Department of Chemistry Lomonosov Moscow State University119991MoscowRussia Laboratory of Arctic Mineralogy and Material sciences Kola Science CentreRussian Academy of Sciences184209ApatityRussia Geological Institute Kola Science CentreRussian Academy of Sciences184209ApatityRussia State Scientific Center of Applied Microbiology and Biotechnology of Rospotrebnadzor 24 Block A142279ObolenskRussia

Novel Ca_(8)CuRE(PO_(4))_(7)where RE^(3+)=Eu^(3+),Tb^(3+),Dy^(3+),Ho^(3+)and Er^(3+)were synthesized by a solid-state method in *** structures of the samples were characterized by powder X-ray diffraction using Rietveld refinement to determine the occupation of crystal *** samples are found to have a centrosymmetric structure with space group R3c,as shown by dielectric *** synthesized Ca_(8)CuRE(PO_(4))_(7)samples have multifunctional *** Cu^(2+)ions provide antibacterial properties,while the rare earth elements ions exhibit luminescence properties,and theβ-Ca_3(PO_(4))_(2)-type host is *** photoluminescence properties of RE^(3+)ions were studied and compared with other simmilar Ca_(8)MRE(PO_(4))_(7)phosphates,where M is a divalent *** photoluminescence intensity quenching in terms of energy transfer from RE^(3+)to Cu^(2+)is *** bioactive properties were studied in relation to antibacterial activity against *** and *** syntesized Ca_(8)CuRE(PO_(4))_(7)samples demonstrate very high and stable inhibition of bacteria *** correlation between crystal structure and properties is *** combining multiple approaches to the directio nal design of such materials,several important properties within a single chemical compound to achieve biovisualization and bioactive properties simultaneously can be combined.

关键词： β-Ca_(3)(PO_(4))_(2) Whitlockite-type structure Bioactive phosphates TCP Photoluminescence Rare earths

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Phase transitions and degradation/oxidation mechanisms in lead-free CsSnI3 halide perovskites

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CLEAN ENERGY 2024年第3期8卷 109-115页

作者： Ivanova, Alexandra Golikova, Margarita Luchnikov, Lev Gostishchev, Pavel Shetinin, Igor Voronov, Victor Saranin, Danila Khovaylo, Vladimir Natl Univ Sci & Technol MISIS NUST MISIS Leninsky Ave 4 Moscow 119049 Russia Belgorod State Univ Pobedy St 85 Belgorod 308015 Russia

Halide perovskites possess ultra-low thermal conductivity and show high potential for thermoelectric devices. The chemical properties and molecular structure of halide perovskite materials are not completely stable under ambient conditions, which hinders their use in thermoelectric generators. Changes in the properties of bulk halide perovskite thermoelectrics are accompanied by partial phase transitions and surface oxidation processes. In this paper, we conducted a comprehensive study of the transport and structural properties of CsSnI3, which were pristine by vacuum melting followed by spark plasma sintering. The research results on the electrical transport of these materials revealed that exposure to an inert atmosphere does not deteriorate stability and the properties of the materials remain unchanged. However, prolonged exposure to air leads to a significant degradation of the electrical transport properties. Contrary to thin-film samples, the shift to the double perovskite structure from the perovskite one is limited to a specific surface layer. This change significantly influences the electrical transport of the material while maintaining the essential properties of both perovskite types. [GRAPHICS]

关键词： halide perovskites degradation oxidation transport properties surface STABILITY PHOTOLUMINESCENCE CONDUCTIVITY MOBILITY

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Polyelectrolyte Complexes between Hyperbranched and Linear Polysaccharides: Fucoidan/Chitosan

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Chinese Journal of Polymer science 2024年第4期42卷 468-479页

作者： Ekaterina R.Gasilova Daria N.Poshina Aleksandra O.Sitnikova Natalia N.Saprykina Yury A.Skorik Institute of Macromolecular Compounds of the russian Academy of sciences Bolshoi VO 31St.Petersburg199004Russian Federation

Polyelectrolyte complexes(PECs)of hyperbranched(HB)and linear polysaccharides are promising as more effective encapsulation agents compared to PECs formed by linear *** investigated the PECs between the HB anionic polysaccharide fucoidan(FUC)and the cationic linear polysaccharide chitosan(CS).The FUC had a molecular weight(MW)of 30×*** PECs were prepared in three solvents(water,0.01 and 0.1 mol/L acetic acid)with CS of MW of 15,110 and 170 kDa,and deacetylation degrees(DDA)of 70%and 97%.The structures of the PECs and the initial FUC were investigated by multi-angle static and dynamic light *** the FUC contained 18 wt%of—OSO3 groups and 5 wt%of uronic acid units,it was a“strong-weak”copolyanion,so the HB macromolecules of the FUC formed nanogel particles in 0.1 mol/L AcOH and open branched structures in water,as confirmed by the Kratky *** mixing the solutions of original components,the PEC structures underwent an equilibration period,the duration of which increased with the MW of *** the charge stoichiometry was approached,the PECs shrank;the fractal dimension approached unity,indicating the side-by-side packing of adjacent FUC branches with the help of *** aggregation in the vicinity of the charge compensation was hardly observed,as it occurred in a very narrow *** PEC content at theζ-potential inversion depended on solvents’pH and the DDA of *** the extreme case of core-shell PECs in 0.1 mol/L AcOH,obtained by mixing FUC nanogels with the solutions of high MW CS of 97%DDA,the protruding tails of CS formed a positively charged shell in the whole range of FUC content(10 wt%

关键词： Polyelectrolyte complexes Chitosan Hyperbranched fucoidan Light scattering

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Model of fractured medium and nondestructive control of composite materials

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Chinese Journal of Aeronautics 2024年第2期37卷 93-99页

作者： Vasily GOLUBEV Ilia NIKITIN Katerina BEKLEMYSHEVA Department of Computers science and Numerical Mathematics Moscow Institute of Physics and TechnologyDolgoprudny 141700Russia Mathematical Modeling and Management Department of InformatizationInstitute of Computer Aided Design RASMoscow 123056Russia

Non-destructive testing of composites is an important issue in the modern aircraft *** are susceptible to the barely visible impact damage which can affect the residual strength of the material and occurs both during production and *** continuum model for describing the damaged zone is *** slip theory relations used for a continuous distribution of slip planes are *** the initial stage,the isotropic background model is *** model allows the material slippage along the fractures based on the Coulomb friction law with the small viscous *** this regime,the govern system of equations becomes *** overcome this difficulty,the explicit-implicit grid-characteristic scheme is *** standard ultrasound diagnostic procedure of damaged composite materials is successfully *** with the trivial free-surface fracture model,different reactions on the compression and stretch waves are *** approach provided an effective way for the simulation of complex dynamic behavior of damage zones.

关键词： Non-destructive testing Composite materials Numerical modeling Continuum model Grid-characteristic method

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RBC aggregation,deformation and adhesion to endothelium:Role of nitric oxide derived from L-Arginine and sodium nitroprusside

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Journal of Innovative Optical Health sciences 2024年第5期17卷 53-65页

作者： M.K.Maksimov P.B.Ermolinskiy O.N.Scheglovitova N.N.Sklyankina A.V.Muravyov A.E.Lugovtsov A.V.Priezzhev Faculty of Physics M.V.Lomonosov Moscow State University bld.1subbuilding.2Leninskie goryMoscow 11991Russia N.F.Gamaleya National Research Center for Epidemiology and Microbiology 18 Gamaleya StreetMoscow 123098Russia K.D.Ushinsky Yaroslavl State Pedagogical University 108/1 Respublikanskaya StreetYaroslavl 150000Russia

Red blood cells(RBCs)are the most abundant human blood *** aggregation and deformation strongly determine blood viscosity which impacts hemorheology and *** turn,RBC properties depend on di®erent endogenous and exogenous *** such factor is nitric oxide(NO),which is mainly produced by endothelial cells(EC)from L-arginine amino acid in the circulatory *** the mechanisms of the RBC-endothelium interplay are not clear up to date and considering its possible clinical importance,the aims of this study are to investigate in vitro:(1)The e®ect of L-arginine induced NO on RBC aggregation and adhesion to endothelium;(2)the NO e®ect on RBC aggregation and deformation induced by L-arginine and sodium nitroprusside without the presence of endothelium in the *** RBC aggregation and adhesion to a monolayer of EC were studied using optical tweezers(OT).The RBC deformability and aggregation without endothelium in the samples were studied using the°ow chamber method and Myrenne *** con¯rmed that NO increases deformability and decreases aggregation of *** showed that the soluble guanylate cyclase pathway appears to be the only NO signaling pathway *** the samples with the endothelium,the\bell-shaped"dependence of RBC aggregation force on L-arginine concentration was observed,which improves our knowledge about the process of NO production by ***,data related to L-arginine accumulation by endothelium were obtained:Necessity of the presence of extracellular L-arginine stated by other authors was put under *** our study,NO decreased the RBC-endothelium adhesion,however,the tendency appeared to be weak and was not con¯rmed in another set of *** our knowledge,this is the¯rst attempt to measure the forces of RBC adhesion to endothelium monolayer with OT.

关键词： Red blood cells aggregation L-arginine endothelium optical tweezers Myrenne flow chamber

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