检索结果-南通市图书馆

Influence of wing flexibility on the aerodynamic performance of a tethered flapping bumblebee

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Theoretical & Applied Mechanics Letters 2020年第6期10卷 382-389页

作者： Hung Truong Thomas Engels dmitry Kolomenskiy Kai schneider Aix-Marseille Université CNRSCentrale MarseilleI2MMarseilleFrance University of Rostock Institute of BiosciencesAnimal PhysiologyRostockGermany Global scientific Information and Computing Center Tokyo Institute of TechnologyMegurokuTokyoJapan

The sophisticated structures of flapping insect wings make it challenging to study the role of wing flexibility in insect *** this study,a mass-spring system is used to model wing structural dynamics as a thin,flexible membrane supported by a network of *** vein mechanical properties can be estimated based on their diameters and the Young's modulus of *** order to analyze the effect of wing flexibility,the Young's modulus is varied to make a comparison between two different wing models that we refer to as flexible and highly *** wing models are coupled with a pseudo-spectral code solving the incompressible Navier–stokes equations,allowing us to investigate the influence of wing deformation on the aerodynamic efficiency of a tethered flapping *** to the bumblebee model with rigid wings,the one with flexible wings flies more efficiently,characterized by a larger lift-to-power ratio.

关键词： Insect flight Wing elasticity Mass-spring model Fluid-structure interaction spectral method Volume penalization method

On the Possibilities of using some Modern Three-dimensional Modeling Means in Forensic Examination

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Journal of Forensic science and Medicine 2022年第1期8卷 17-23页

作者： dmitry s Afonin Iryna V Hora Valerii A Kolesnyk Inna I Popovych Iryna V Kuchynska Department of Administrative Activity of Police Odesa State University of Internal AffairsOdesa scientific Center National Academy of the Security Service of Ukraine Department of Criminal Law and Procedure Uzhhorod National UniversityUzhhorod Center for Forensic and special Examinations The Ukrainian Scientific and Research Institute of Special Equipment and Forensic Expertise of the Security Service of UlaaineKyivUkraine

Background:The paper examines the state and prospects of using 3D modeling in solving identification,classification,diagnostic and situational tasks of forensic *** and Objectives:The aim of this study is to analyze the world expert practice of using scientific and technical means of three-dimensional modeling in solving problems of forensic examination,using the example of our country,the leading countries of Europe,as well as the United *** and Methods:The empirical basis of the study is the results of the systematization of scientific and technical means for 3D modeling in solving identification,classification,diagnostic and situational problems of forensic examinations used in the expert practice of Ukraine,the United Kingdom,France,Germany,and the ***:The systematization of modem scientific and technical means for 3D modeling,used in solving identification,classification,diagnostic and situational tasks of forensic examination,has been carried *** analyzed and identified 3D modeling software that most fully meets the requirements of effective forensic expert *** features of the use of effective 3D modeling mean for solving identification,classification,diagnostic and situational tasks of forensic examination,namely the software systems"Toolscan"and"Trasoscan",and the sketchUp program have been ***:The introduction of the sketchUp 8 software into forensic expert activities will increase the effectiveness of the modeling method in forensic examinations,which,in turn,will have an impact on the effectiveness of expert conclusions,increase their evidentiary value and,as a result,contribute to the entire process of a criminal investigation.

关键词： Classification tasks diagnostic tasks forensic practice identification tasks photogrammetric modeling simulation modeling three-dimensional model

Nonlinear polaritons in a monolayer semiconductor coupled to optical bound states in the continuum

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Light(science & Applications) 2020年第1期9卷 1480-1487页

作者： Vasily Kravtsov Ekaterina Khestanova Fedor A.Benimetskiy Tatiana Ivanova Anton K.samusev Ivan s.sinev dmitry Pidgayko Alexey M.Mozharov Ivan s.Mukhin Maksim s.Lozhkin Yuri V.Kapitonov Andrey s.Brichkin Vladimir D.Kulakovskii Ivan A.shelykh Alexander I.Tartakovskii Paul M.Walker Maurice s.skolnick dmitry N.Krizhanovskii Ivan V.Iorsh ITMO University Saint Petersburg 197101Russia st.Petersburg Academic University Saint Petersburg 194021Russia saint Petersburg state University ul.Ulyanovskaya 1Saint Petersburg 198504Russia Institute of solid state Physics RASChernogolovka 142432Russia science Institute University of IcelandDunhagi 3IS-107ReykjavikIceland Department of Physics and Astronomy University of SheffieldSheffield S37RHUK

Optical bound states in the continuum(BICs)provide a way to engineer very narrow resonances in photonic *** extended interaction time in these systems is particularly promising for the enhancement of nonlinear optical processes and the development of the next generation of active optical ***,the achievable interaction strength is limited by the purely photonic character of optical ***,we mix the optical BIC in a photonic crystal slab with excitons in the atomically thin semiconductor Mose_(2) to form nonlinear exciton-polaritons with a Rabi splitting of 27 meV,exhibiting large interaction-induced spectral *** asymptotic BIC-like suppression of polariton radiation into the far field toward the BIC wavevector,in combination with effective reduction of the excitonic disorder through motional narrowing,results in small polariton linewidths below 3 *** with a strongly wavevector-dependent Q-factor,this provides for the enhancement and control of polariton–polariton interactions and the resulting nonlinear optical effects,paving the way toward tuneable BIC-based polaritonic devices for sensing,lasing,and nonlinear optics.

关键词： polar nonlinear continuum

Hepatitis B virus markers in hepatitis B surface antigen negative patients with pancreatic cancer:Two case reports

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Hepatology 2022年第7期14卷 1512-1519页

作者： sergey Batskikh sergey Morozov dmitry Kostyushev Department of Hepatology Moscow Clinical Research Center named after A.S.LoginovMoscow 111123Russia Department of Gastroenterology Hepatology and NutritionFederal Research Center of Nutrition and BiotechnologyMoscow 115446Russia Laboratory of Genetic Technologies Martsinovsky Institute of Medical ParasitologyTropical and Vector-Borne DiseasesFirst Moscow State Medical University(Sechenov University)Moscow 119991Russia Division of Biotechnology Sirius University of Science and TechnologySochi 354340Russia

BACKGROUND Hepatitis B virus(HBV)is a known carcinogen that may be involved in pancreatic cancer *** of HBV biomarkers[especially expression of HBV regulatory X protein(HBx)]within the tumor tissue may provide direct support for ***,there is still a lack of such reports,particularly in non-endemic regions for HBV *** we present two cases of patients with pancreatic ductal adenocarcinoma,without a history of viral hepatitis,in whom the markers of HBV infection were detected in blood and in the resected pancreatic *** sUMMARY The results of examination of two patients with pancreatic cancer,who gave informed consent for participation and publication,were the source for this *** standards of care,special examination to reveal occult HBV infection was *** included blood tests for HBsAg,anti-HBc,anti-HBs,HBV DNA,and pancreatic tissue examinations with polymerase chain reaction for HBV DNA,pregenomic HBV RNA(pgRNA HBV),and covalently closed circular DNA HBV(cccDNA)and immunohistochemistry staining for HBxAg and *** subjects were operated on due to pancreatic ductal adenocarcinoma and serum HBsAg was not ***,in both of them anti-HBc antibodies were detected in blood,although HBV DNA was not *** of the resected pancreatic tissue gave positive results for HBV DNA,expression of HBx,and active cellular proliferation by Ki-67 index in both ***,HBV pgRNA and cccDNA were detected only in case *** These cases may reflect potential involvement of HBV infection in the development of pancreatic cancer.

关键词： Pancreatic cancer Pancreatic ductal adenocarcinoma Hepatitis B virus Previous hepatitis B Anti-HBc Hepatitis B virus X antigen

Real-time decay of fluorinated fullerene molecules on Cu（001） surface controlled by initial coverage

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 2018年第4期11卷 2069-2082页

作者： Andrey I. Oreshkin dmitry A. Muzychenko sergey I. Oreshkin Vladimir A. Yakovlev Palanichamy Murugan s. selva Chandrasekaran Vijay Kumar Rauf Z. Bakhtizin Department of Physics Lomonosov Moscow State University 119991 Moscow Russia sternberg Astronomical Institute Lomonosov Moscow State University 119234 Moscow Russia Institute of Petrochemical synthesis Russian Academy of Sciences 119991 Moscow Russia CsIR Central Electrochemical Research Institute Karaikudi 630003 Tamil Nadu India Dr. Vijay Kumar Foundation 1969 Sector 4 Gurgaon 122001 Haryana India Center for Informatics School of Natural Sciences Shiv Nadar University NH91 Tehsil Dadari Gautam Budh Nagar 201314 Uttar Pradesh India Department of Physical Electronics Bashkir State University 450074 Ufa Russia

In this study, the evolution of C60F18 molecules on a Cu（001） surface was studied by means of scanning tunneling microscopy and density functional theory calculations. The results showed that fluorinated fuUerenes （tortoise-shaped polar C60F18） decay on Cu（001） surfaces by a step-by-step detachment of F atoms from the C60 cage. The most favorable adsorption configuration was realized when the F atoms of C60F18 pointed towards the Cu surface and six F atoms were detached from it. The results also showed that a further decay of C60F12 molecules strongly depended on the initial C60F18 coverage. The detached F atoms initially formed a two-dimensional （2D） gas phase which then slowly transformed into F-induced surface structures. The degree of contact between the C60F12 molecules and the Cu（001） surface depended on the density of the 2D gas phase. Hence, the life-time of fluorinated fullerenes was determined by the density of the 2D gas phase, which was affected by the formation of new F-induced structures and the decay of C60F12 molecules.

关键词： fluorinated fullerene (001) Cu surface two-dimensional (2D)molecular island 2D gas phase self-assembling molecules scanning tunneling microscopy (sTM) density functional theory(DFT)

structure,magnetic and adsorption properties of novel FePt/h-BN heteromaterials

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 2023年第1期16卷 1473-1481页

作者： Anton s.Konopatsky Vladislava V.Kalinina Alena s.savchenko Denis.V.Leybo Ekaterina V.sukhanova Viktor s.Baidyshev Zakhar I.Popov Andrey V.Bondarev Josef Polčák dmitry V.shtansky National University of science and Technology(MIsIs) Leninskiy prospect 4Moscow119049Russia Emanuel Institute of Biochemical Physics RAs Kosygina 4Moscow119334Russia Katanov Khakas state University 90 Lenin pr.655017 AbakanRussia Plekhanov Russian University of Economics 36 Stremyanny per.Moscow 117997Russia Department of Control Engineering Faculty of Electrical EngineeringCzech Technical University in PragueTechnicka 2Prague 16627Czech Republic CEITEC-Central European Institute of Technology Brno University of TechnologyPurkyňova 123Brno 61200 BrnoCzech Republic

Nanomaterials with high specific surface area and high absorption capacity are attracting increased interest aimed at imparting the desired magnetic *** work is devoted to the study of the effect of heat treatment in a hydrogen atmosphere on the microstructure,adsorption and magnetic properties of heterogeneous FePt/h-BN *** via the polyol process,FePt nanoparticles(NPs)had a sizestributed over the surface of hexagonal boron nitride(h-BN)*** temperature-activated fcc→fct phase transformation in ultrafine FePt NPs has been well *** NPs act as active centers dissociating H2 molecules and transfer adsorbed hydrogen atoms to the *** functional theory(DFT)calculations also indicate that the h-BN substrate can absorb hydrogen adsorbed on the FePt *** hydrogen circulation in the FePt/h-BN system promoted the fcc→fct phase transformation and allowed to control the magnetic ***/h-BN nanomaterials also exhibited a high adsorption capacity with respect to various organic dyes.

关键词： FePt/h-BN nanomaterials polyol synthesis phase transformations magnetic properties adsorption

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

俄罗斯未来国家形象的青年政治认同

西伯利亚研究 2024年第2期51卷 20-28页

作者： [俄]Д.В.索苏诺夫 Д.В.扎维留欣邹秀婷(译) 沃罗涅日国立大学历史系社会学与政治学教研室沃罗涅日国立大学黑龙江省社会科学院俄罗斯研究所

2019—2023年,俄罗斯青年群体的政治认同发生了比较大的变化,年轻一代开始参与社会政治进程。当前形势下,俄罗斯的国家政治制度能否延续,取决于年轻一代能否以政治精英制定的“游戏规则”为基础融入政治生活。在确定政治日程目标和设置... 详细信息

2019—2023年,俄罗斯青年群体的政治认同发生了比较大的变化,年轻一代开始参与社会政治进程。当前形势下,俄罗斯的国家政治制度能否延续,取决于年轻一代能否以政治精英制定的“游戏规则”为基础融入政治生活。在确定政治日程目标和设置政治日程的背景下,关注青年人对自己在国家政治体系中地位的变化,以及跟踪研究青年人对俄罗斯国际地位和作用的态度变化至关重要。分析国家政治领导层发布的战略性文件,对比俄罗斯新一代人的期望与政府的官方表述可以发现,俄罗斯青年和政治精英对国家未来形象的认知存在差异。出现这种情况的原因在于,大多数青年人对社会国家~((1))和最低限度参与国家对外政策的要求很高,导致家长式统治、社会认同程度低等问题。当代俄罗斯青年政治认同高质量转型的先决条件正在形成,这为解决政府与社会互动的深层问题提供了可能性。原文发表于俄罗斯《俄罗斯与亚太》杂志2023年第4期~((2)),经作者同意在《西伯利亚研究》以中文刊发。

关键词：政治认同青年政治议程俄罗斯未来形象

A class of high-mobility layered nanomaterials by design

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Journal of Materials science & Technology 2023年第33期164卷 179-187页

作者： dmitry V.Averyanov Ivan s.sokolov Oleg E.Parfenov Alexander N.Taldenkov Oleg A.Kondratev Andrey M.Tokmachev Vyacheslav G.storchak National Research Center “Kurchatov Institute” Kurchatov Sq.1Moscow 123182Russia

Design of materials with particular functional properties is indispensable albeit very *** and structural analogies can be helpful in this endeavor,especially when a particular combination of properties is sought *** aim is to bundle together 3 characteristics:high carrier mobility,magnetism,and scalability to nanomaterials in the form of a film–such a combination is particularly advantageous for ***,inspired by recent studies of MAl_(2)si_(2)and related compounds,we develop magnetic EuAl_(2)Ge_(2)and non-magnetic srAl_(2)Ge_(2)nanomaterials with high carrier *** syntheses employing sacrificial 2D templates result in epitaxial films of MAl_(2)Ge_(2)seamlessly integrated with *** syntheses are followed by a study of the atomic structure,magnetic and electron transport *** particular,the films demonstrate high carrier mobility,exceeding 10,000 cm^(2)V^(-1)s^(-1)in the case of EuAl_(2)Ge_(2),making the materials appealing for *** together,MAl_(2)Ge_(2)and MAl_(2)si_(2)form a class of high-mobility layered nanomaterials.

关键词： High carrier mobility Magnetism srAl_(2)Ge_(2) EuAl_(2)Ge_(2) Germanium

Microscopic theory of exciton and trion polaritons in doped monolayers of transition metal dichalcogenides

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

npj Computational Materials 2022年第1期8卷 891-900页

作者： Yaroslav Vladimirovich Zhumagulov salvatore Chiavazzo dmitry Romanovich Gulevich Vasili Perebeinos Ivan Andreevich shelykh Oleksandr Kyriienko University of Regensburg Regensburg93040Germany Department of Physics and Engineering ITMO UniversitySt.Petersburg197101Russia Department of Physics and Astronomy University of ExeterStocker RoadExeterEX44QLUnited Kingdom Department of Electrical Engineering University at BuffaloThe State University of New YorkBuffaloNY14260USA science Institute University of IcelandDunhagi-3IS-107ReykjavikIceland

We study a doped transition metal dichalcogenide (TMDC) monolayer in an optical *** the microscopic theory,we simulate spectra of quasiparticles emerging due to the interaction of material excitations and a high-finesse optical mode,providing a comprehensive analysis of optical spectra as a function of Fermi energy and predicting several modes in the strong light-matter coupling *** addition to exciton-polaritons and trion-polaritons,we report polaritonic modes that become bright due to the interaction of excitons with free *** large doping,we reveal strongly coupled modes corresponding to excited trions that hybridize with a cavity *** also demonstrate that the increase of carrier concentration can change the nature of the system’s ground state from the dark to the bright *** results offer a unified description of polaritonic modes in a wide range of free electron densities.

关键词： polar transition theory