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等离子体湍流中的能量级串和耗散:从流体尺度到动力学尺度的数值模拟

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等离子体湍流中的能量级串和耗散:从流体尺度到动力学尺度的数值...

Lattice-based digital signatures

第十届全国流体力学青年研讨会

作者：万敏平杨艳 William Matthaeus Vadim Roytershteyn Tulasi Parashar 史一鹏陈十一南方科技大学力学与航空航天系北京大学工学院湍流与复杂系统国家重点实验室美国特拉华大学物理与天文系

本文主要探讨空间等离子体湍流中的能量级串和耗散问题,通过可压缩磁流体动力学(MHD)模拟和动力学尺度的等离子体数值模拟来研究这一跨尺度的物理问题。

关键词：等离子体磁流体动力学能量级串耗散

来源： cnki会议评论

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National Science Review 2021年第9期8卷 9-10页

作者： vadim Lyubashevsky Zurich Research Laboratory IBM Research

Digital signatures and key exchange protocols are the two most important public key cryptographic primitives used in the electronic transmission of data. The goal of key exchange is to preserve the secrecy of the communication, while the goal of digital signatures is to guarantee the authenticity of the exchanged messages. Constructions of digital signature schemes based on classical mathematical assumptions appeared shortly following the invention of public key cryptography in the late 1970s. And just like with key exchange,

关键词： lattice cryptography digital signatures standardization

Heterogeneous LBM Simulation Code with LRnLA Algorithms

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Communications in Computational Physics 2023年第1期33卷 214-244页

作者： vadim Levchenko Anastasia Perepelkina Keldysh Institute of Applied Mathematics RAS

A design of a new heterogeneous code for LBM simulations is proposed.By heterogeneous computing wemean a collaborative computation on CPU and GPU,which is characterized by the following features:the data is distributed between CPU and GPU memory spaces taking advantage of both parallel hierarchies;the capabilities of both SIMT GPU and SIMD GPU parallelization are used for calculations;the algorithms in use efficiently conceal the CPU-GPU data exchange;the subdivision of the computing task is performed with an account for the strong points of both processing units:high performance of GPU,low latency,and advanced memory hierarchy of CPU.This code is a continuation of our work in the development of LRnLA codes for LBM.Previous LRnLA codes had good efficiency both for CPU and GPU computing,and allowed GPU simulation performed on data stored in CPU RAM without performance loss on CPU-GPU data transfer.In the new code,we use methods and instruments that can be flexibly adapted to GPU and CPU instruction sets.We present the theoretical study of the performance of the proposed code and suggest implementation techniques.The bottlenecks are identified.As a result,we conclude that larger problems can be simulated with higher efficiency in the heterogeneous system.

关键词： LBM Roofline memory-bound GPU LRnLA

Thermogravimetric,kinetic study and gas emissions analysis of the thermal decomposition of waste-derived fuels

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Journal of Environmental Sciences 2024年第3期137卷 155-171页

作者： vadim V.Dorokhov Galina S.Nyashina Pavel A.Strizhak Heat and Mass Transfer Laboratory National Research Tomsk Polytechnic University30 Lenin AvenueTomsk 634050Russia

A wide range of wastes can potentially be used to generate thermal and electrical energy.The co-combustion of several types of waste as part of water-containing waste-derived fuels is a promising method for their recovery.In this research,we use thermogravimetric analysis and differential scanning calorimetry to study the thermal behavior and kinetics of coal slime,biomass,waste oils,and blends on their basis.We also analyze the concentrations of gaseous emissions.The results show that biomass,oils,and coal slime significantly affect each other in the course of their co-combustion when added to slurry fuels.The preparation of coal-water slurry based on slime and water reduced the ignition and burnout temperature by up to 16%.Adding biomass and waste oils additionally stimulated the slurry ignition and burnout,which occurred at lower temperatures.Relative to dry coal slime,threshold ignition temperatures and burnout temperatures decreased by 6%–9%and 17%–25%,respectively.Also,the use of biomass and waste oils as part of slurries inhibited NOхand SO_(2)emission by 2.75 times.According to the kinetic analysis,added biomass and waste turbine oil provide a 28%–51%reduction in the activation energy as compared to a coal-water slurry without additives.

关键词： Coal-water slurry Water-containing composite fuels Combustion Emission Kinetic TGA-DSC

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Parameterization of the propeller thrust for modelling ship braking in ice channel behind icebreaker

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Transportation Safety and Environment 2023年第1期5卷 41-48页

作者： vadim K.Goncharov Natalia Yu.Klementieva Saint-Petersburg State Marine Technical University Saint-Petersburg190121Russia Krylov State Research Centre Ice Basin LaboratorySaint-Petersburg196158Russia.

Cargo ship sailing within the ice channel that an assisting icebreaker tracks in the compact ice cover is the usual navigation practice for difficult ice conditions in freezing seas and Arcticwater areas.When the icebreaker or an ahead vessel stops before the insuperable ice obstacle or because of engine trouble,the danger of an emergency appears,namely of collision with the icebreaker or the ahead ship,if the interval between them is not sufficient for effective braking and stopping.The paper presents the equation that describes the ship braking process within an ice channel and includes the thrust of the propeller that works under the reverse regime.The specific of this regime is the following:the ship continues the motion‘forwards’and the propeller rotates‘backwards’.An analytical method for description of the ship propeller work on the reverse regime is absent because of the detached flow on its blades.The paper describes the developed empirical method of this regime parameterization on the basis of serial models of propeller testing.The outcomes of this investigation are applied to a ship braking process simulation and the evaluation of the safe interval between the ship and the icebreaker.

关键词： ship braking ice channel propeller action curve advance thrust reverse regime

Orbits of 152 globular clusters of the Milky Way galaxy constructed from Gaia DR2

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Research in Astronomy and Astrophysics 2021年第7期21卷 177-191页

作者： Anisa Talgatovna Bajkova vadim vadimovich Bobylev Pulkovo Astronomical Observatory St.Petersburg 196140Russia

We present orbits and their properties for 152 globular clusters of the Milky Way galaxy obtained using average Gaia DR2 proper motions and other astrometric data from the list of Vasiliev. For orbital integration we have applied the axisymmetric model of the Galactic potential based on the Navarro-Frenk-White dark halo, and modified by Bajkova & Bobylev utilizing circular velocities of Galactic objects in a wide region of Galactocentric distances(up to 200 kpc) from the Bhattacharjee et al. catalog. Based on the analysis of the obtained orbits, we have modified the composition of the subsystems of globular clusters presented in Massari et al..

关键词： (Galaxy) globular clusters general

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Analysis of the Quantity and Causes of Outages in LV/MV Electric Grids

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CSEE Journal of Power and Energy Systems 2020年第3期6卷 537-542页

作者： Alexander Vinogradov Alina Vinogradova vadim Bolshev Laboratory of power supply and electrical safety Federal Scientific Agroengineering Center VIMMoscow109428 Russia

The paper considers the quantity and causes of outages in electric grids of low and medium voltages using the example of an electric grid of a regional power supply company.The main types of damage to the equipment of power lines and transformer substations were identified.Data on other areas of rural and urban electric grids are also analyzed.The main directions for reducing the quantity of outages in electric grids are proposed based on this analysis.Among them,there are the use of isolated wires in power transmission lines,the improvement of design of switching devices,switches and terminals of transformers,the application of technical condition diagnostics,the disaggregating of power lines and the increase of protection sensitivity of power lines.Most of the causes of equipment damage can be prevented by increasing the maintenance level of this equipment.

关键词： Electrical network grid power line power outages power supply reliability PTL transformer

Prediction of Moments in the Particles on Demand Method for LBM

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Communications in Computational Physics 2023年第1期33卷 144-173页

作者： Elizaveta Zipunova Anastasia Perepelkina vadim Levchenko German Zvezdin Keldysh Institute of Applied Mathematics RAS 4 Miusskaya sq.MoscowRussia125047 Moscow State University 1 Ulitsa KolmogorovaMoscowRussia119991

PonD is a method to extend LBM calculations to arbitrary ranges of Mach number and temperature.The current work was motivated by the issue of mass,momentum and energy conservation in the PonD method for LBM.The collision guarantees their conservation,thus,the study involves all aspects of the streaming step:both coordinate and velocity space discretizations,gauge transfer method,resolution of the scheme implicitness.After obtaining the expressions for the change of moments in the system in a time update of the scheme,it was found that the scheme can be formulated as explicit in some cases.Thus,we found the sufficient conditions to make Pond/RegPonD computations explicit and mass,momentum,and energy conserving.The scheme was implemented in the explicit form,and validated for several test cases.

关键词： LBM compressible off-grid

Probing the dynamic thermodynamic resolution and biological activity of Cu(Ⅱ) and Pd(Ⅱ) complexes with Schiff base ligand derived from proline

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Chinese Chemical Letters 2024年第4期35卷 99-105页

作者： Tao Yu vadim A.Soloshonok Zhekai Xiao Hong Liu Jiang Wang State Key Laboratory of Drug Research Shanghai Institute of Materia MedicaChinese Academy of SciencesShanghai 201203China School of Pharmacy University of Chinese Academy of SciencesBeijing 100049China Department of Organic Chemistry Ⅰ Faculty of ChemistryUniversity of the Basque Country UPV/EHUSan Sebastian 20018Spain IKERBASQUE Basque Foundation for ScienceBilbao 48013Spain School of Pharmaceutical Science and Technology Hangzhou Institute for Advanced StudyUCASHangzhou 310024China Lingang Laboratory Shanghai 200031China

Schiff base metal complexes are of great importance in pharmaceutical science owing to their unique chemical properties, which enable them to exhibit diverse biological activities such as anti-bacterial,anti-oxidant, anti-inflammatory, and anti-tumor properties. Furthermore, Schiff base metal complexes can serve as reagents and catalysts in chemical reactions. This review aims to provide an overview of our recently published studies on Cu(Ⅱ) and Pd(Ⅱ) complexes derived from proline Schiff base ligands. We also discuss the potential applications of these metal complexes in the fields of antibacterial and chiral resolution.

关键词： Schiff bases Biological activity Tailor-made amino acids Asymmetric synthesis Chiral tridentate ligands Square-planar Cu(Ⅱ)-complexes Square-planar Pd(Ⅱ)-complexes

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