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Communications in Computational Physics 2012年第4期11卷 1279-1299页

作者： Yuqi Wu xiao-Chuan cai Department of Applied Mathematics University of Colorado at BoulderBoulderCO 80309USA Department of Computer Science University of Colorado at BoulderBoulderCO 80309USA

We introduce and study a parallel domain decomposition algorithm for the simulation of blood flow in compliant arteries using a fully-coupled system of nonlinear partial differential equations consisting of a linear elasticity equation and the incompressible Navier-Stokes equations with a resistive outflow boundary *** system is discretized with a finite element method on unstructured moving meshes and solved by a Newton-Krylov algorithm preconditioned with an overlapping restricted additive Schwarz *** resistive outflow boundary condition plays an interesting role in the accuracy of the blood flow simulation and we provide a numerical comparison of its accuracy with the standard pressure type boundary *** also discuss the parallel performance of the implicit domain decomposition method for solving the fully coupled nonlinear system on a supercomputer with a few hundred processors.

关键词： Fluid-structure interaction blood flow mesh movement resistive boundary condition additive Schwarz domain decomposition parallel computing

Theoretical Study on the Ordered Structure in Lanthanum-Modified Lead Zirconate Titanate

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Chinese Physics Letters 1996年第9期13卷 696-699页

作者： guI Hong ZHANG xiao-wen gu Bing-lin Department of Materials Science and Engineering Department of Physics Tsinghua UniversityBeijing 100084

The 1/2{111}-type ordered structure observed in lanthanum-modified lead zirconate titanate has been proved to be stable in the next-nearest-neighbor approximation by the eightpoint cluster variation *** order parameter as a function of the composition of La3+and lead vacancies and the order-disorder phase diagram have been obtained.

关键词： method lanthanum Modified

The research on the substitution effect between the wireless and fixed telecommunication industry

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The Journal of China Universities of Posts and Telecommunications 2006年第3期13卷 102-106页

作者： DOU cai-lan LONG xiao-yu Department of Economics and Management Xi'an Institute of Posts and Teleconununications Xi'an 710061 China

Wireless telecommunication has developed at a rapid pace than the fixed telecommunication since the last decades of twentieth century. This article analyzes the effect wireless mobile telecom substitutes for the fixed telecom by employing the normal theory of substitution and econometrics model. The analytical results are consistent with the reality, and it has been observed that the relation between the wireless and fixed telecommunication industry has changed from state of being complementary in the early last decades of twentieth century to that of being substituted at present. Moreover, the enhanced progress of telecommunication technology especially in wireless areas enriches customers＇ demands in terms of multimedia contents thereby changing their communication style, which significantly promotes the rapid growth of wireless mobile communication and strengthens the effect of the substitute.

关键词： effect of substitute wireless telecommunication,fixed telecommunication telecommunication industry

Spatiotemporal dynamics in a network composed of neurons with different excitabilities and excitatory coupling

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Science China(Technological Sciences) 2016年第12期59卷 1943-1952页

作者： xiao Wei Wei gu Hua guang LIU Ming Rui School of Aerospace Engineering and Applied Mechanics Tongji University Department of Mathematics Shanghai Jiao Tong University

Spiral waves have been observed in the biological experiments on rat cortex perfused with drugs which can block inhibitory synapse and switch neuron excitability from type II to type I. To simulate the spiral waves observed in the experiment, the spatiotemporal patterns are investigated in a network composed of neurons with type I and II excitabilities and excitatory coupling. Spiral waves emerge when the percentage(p) of neurons with type I excitability in the network is at middle levels, which is dependent on the coupling strength. Compared with other spatial patterns which appear at different p values, spiral waves exhibit optimal spatial correlation at a certain spatial frequency, implying the occurrence of spatial coherence resonance-like phenomenon. Some dynamical characteristics of the network such as mean firing frequency and synchronous degree can be well interpreted with distinct properties between type I excitability and type II excitability. The results not only identify dynamics of spiral waves in neuronal networks composed of neurons with different excitabilities, but also are helpful to understanding the emergence of spiral waves observed in the biological experiment.

关键词： spiral wave neuronal network spatiotemporal dynamics type I excitability type II excitability coherence resonance

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煤表面含氧官能团吸附氮化物的模拟计算研究

原子与分子物理学报 2025年第2期42卷 1-7页

作者：孙潇镝唐克王聚财富添洪新辽宁工业大学化学与环境工程学院锦州121001

煤表面六种常见的官能团结构单元包括酚羟基Ph-OH、羧基-COOH、羰基-C=O、醚键-O-、醇羟基R-OH和烷基R,采用巨正则蒙特卡洛(GCMC)和密度泛函理论(DFT)从原子层面模拟计算煤表面官能团对苯胺、吡啶、喹啉三种典型氮化物的吸附性能.通过... 详细信息

煤表面六种常见的官能团结构单元包括酚羟基Ph-OH、羧基-COOH、羰基-C=O、醚键-O-、醇羟基R-OH和烷基R,采用巨正则蒙特卡洛(GCMC)和密度泛函理论(DFT)从原子层面模拟计算煤表面官能团对苯胺、吡啶、喹啉三种典型氮化物的吸附性能.通过计算分析前线轨道、吸附能及分子间吸附距离等参数,探究三种氮化物在煤表面不同官能团上的吸附机理,结果表明煤表面模型上各官能团对三种氮化物的吸附强弱顺序均为:-COOH>R-OH>Ph-OH>-C=O>-O->R,三种氮化物在煤表面官能团的吸附强弱顺序为:吡啶>喹啉>苯胺.

关键词：煤官能团氮化物模拟吸附

A comprehensive fluid-solid coupling dynamic simulation for spatiotemporal distribution of regression rate in hybrid rocket motors

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Chinese Journal of Aeronautics 2024年第9期37卷 100-112页

作者： Tianfang WEI guobiao cai Hui TIAN Xiangyu MENG Xianzhu JIANG xiaoming gu School of Astronautics Beihang UniversityBeijing 100191China Key Laboratory of Spacecraft Design Optimization&Dynamic Simulation Technologies Ministry of Education Beijing 100191China

The spatiotemporal distribution characteristics of the regression rate are crucial aspects of the research on Hybrid Rocket Motor(HRM). This study presents a pioneering effort in achieving a comprehensive numerical simulation of fluid dynamics and heat transfer in both the fluid and solid regions throughout the entire operation of an HRM. To accomplish this, a dynamic grid technique that incorporates fluid–solid coupling is utilized. To validate the precision of the numerical simulations, a firing test is conducted, with embedded thermocouple probes being used to measure the inner temperature of the fuel grain. The temperature variations in the solid fuel obtained from both experiment and simulations show good agreement. The maximum combustion temperature and average thrust obtained from the simulations are found to deviate from the experimental results by only 3.3% and 2.4%, respectively. Thus, it can be demonstrated that transient numerical simulations accurately capture the fluid–solid coupling characteristics and transient regression rate. The dynamic simulation results of inner flow field and solid region throughout the entire working stage reveal that the presence of vortices enhances the blending of combustion gases and improves the regression rate at both the front and rear ends of the fuel grain. In addition, oscillations of the regression rate obtained in the simulation can also be well corresponded with the corrugated surface observed in the experiment. Furthermore, the zero-dimension regression rate formula and the formula describing the axial location dependence of the regression rate are fitted from the simulation results, with the corresponding coefficients of determination(R^(2)) of 0.9765 and 0.9298, *** research serves as a reference for predicting the performance of HRM with gas oxygen and polyethylene, and presents a credible way for investigating the spatiotemporal distribution of the regression rate.

关键词： Hybrid Rocket Motor(HRM) Transient numerical simulation Fluid-solid couplingheat transfer Spatiotemporal distribution of regression rate Dynamic grid

Carbon-coated lithium titanate: effect of carbon precursor addition processes on the electrochemical performance

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Frontiers of Chemical Science and Engineering 2021年第1期15卷 148-155页

作者： Shilei Ding Zelong Jiang Jing gu Hongliang Zhang Jiajia cai Dongdong Wang School of Energy and Environment Anhui University of TechnologyMaanshan 243002China School of Chemistry and Chemical Engineering Anhui University of TechnologyMaanshan 243002China Analysis and Testing Central Facility Anhui University of TechnologyMaanshan 243002China

In this paper,two carbon-coated lithium titanate(LTO-C1 and LTO-C2)composites were synthesized using the ball-milling-assisted calcination method with different carbon precursor addition *** physical and electrochemical properties of the as-synthesized negative electrode materials were characterized to investigate the effects of two carbon-coated LTO synthesis processes on the electrochemical performance of *** results show that the LTO-C2 synthesized by using Li2CO3 and TiO2 as the raw materials and sucrose as the carbon source in a one-pot method has less polarization during lithium insertion and extraction,minimal charge transfer impedance value and the best electrochemical performance among all *** the current density of 300 mA·h·g^(-1),the LTO-C2 composite delivers a charge capacity of 126.9 mA·h·g^(-1),and the reversible capacity after 300 cycles exceeds 121.3 mA·h·g^(-1) in the voltage range of 1.0–3.0 ***,the electrochemical impedance spectra show that LTO-C2 has higher electronic conductivity and lithium diffusion coefficient,which indicates the advantages in electrode kinetics over LTO and *** results clarify the best electrochemical properties of the carbon-coated LTO-C2 composite prepared by the one-pot method.

关键词： lithium titanate carbon-coated carbon precursor synthetic process

Numerical study on transom stern ventilation and resistance of high-speed ship in calm water

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Journal of Hydrodynamics 2022年第5期34卷 864-875页

作者： Hui Wang Ren-chuan Zhu Meng-xiao gu Le Zha State Key Laboratory of Ocean Engineering School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China Marine Design and Research Institute of China Shanghai200011China

A transom stern is a common design feature for a high-speed *** the present study,the transom stern ventilation of NPL 3b,5b hull is investigated by three methods:H−H formula,Doctors’formula,and computational fluid dynamics(CFD)method at *** the CFD method,the ratios of the wave elevation and wetted area are used to determine the transom *** of results show that Doctors’formula is more accurate to calculate the critical transom draft Froude *** then a Rankine panel method(RPM)based on the high-order boundary element method incorporated the modified transom stern condition is implemented to evaluate the steady wave problem of a high-speed fishery patrol ship in calm ***,free-surface(FS)and double body(DB)simulations based on Star-CCM+are carried out to obtain the wave-making resistance and total *** results of the resistance and wave pattern around the fishery patrol ship computed by RPM show generally good agreement with experimental measurement and CFD *** results indicate that the developed Rankine panel method with transom condition could predict the resistance of high-speed displacement ships with good accuracy.

关键词： Transom ventilation computational fluid dynamics(CFD)method Rankine panel method(RPM) high-speed ship double body simulation resistance

Deep hybrid: Multi-graph neural network collaboration for hyperspectral image classification

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Defence Technology（防务技术） 2023年第5期23卷 164-176页

作者： Ding Yao Zhang Zhi-li Zhao xiao-feng cai Wei He Fang cai Yao-ming Wei-Wei cai Xi'an Research Institute of High Technology Xi'an710025China The School of Computer Science China University of GeosciencesWuhan430074China The School of Artificial Intelligence and Computer Science Jiangnan UniversityWuxi214122China

With limited number of labeled samples,hyperspectral image(HSI)classification is a difficult Problem in current *** graph neural network(GNN)has emerged as an approach to semi-supervised classification,and the application of GNN to hyperspectral images has attracted much ***,in the existing GNN-based methods a single graph neural network or graph filter is mainly used to extract HSI features,which does not take full advantage of various graph neural networks(graph filters).Moreover,the traditional GNNs have the problem of *** alleviate these shortcomings,we introduce a deep hybrid multi-graph neural network(DHMG),where two different graph filters,i.e.,the spectral filter and the autoregressive moving average(ARMA)filter,are utilized in two *** former can well extract the spectral features of the nodes,and the latter has a good suppression effect on graph *** network realizes information interaction between the two branches and takes good advantage of different graph *** addition,to address the problem of oversmoothing,a dense network is proposed,where the local graph features are *** dense structure satisfies the needs of different classification targets presenting different ***,we introduce a GraphSAGEbased network to refine the graph features produced by the deep hybrid *** experiments on three public HSI datasets strongly demonstrate that the DHMG dramatically outperforms the state-ofthe-art models.

关键词： Graph neural network Hyperspectral image classification Deep hybrid network

Analysis of air quality characteristics of Beijing–Tianjin–Hebei and its surrounding air pollution transport channel cities in China

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Journal of Environmental Sciences 2020年第1期32卷 213-227页

作者： Cuicui xiao Miao Chang Peikun guo Meifeng gu Yang Li School of Environment Tsinghua University

Beijing–Tianjin–Hebei(BTH)and its surrounding areas are very important to air pollution control in *** analyze the characteristics of BTH and its surrounding areas of China,we collected 5,641,440 air quality data from 161 air monitoring stations and 37,123,000 continuous monitoring data from air polluting enterprises in BTH and surrounding cities to establish an indicator system for urban air quality *** results showed that particulate matter with aerodynamic diameters of<2.5μm(PM2.5),particulate matter with aerodynamic diameters of<10μm(PM10)and SO2 improved significantly in 31 cities from2015 to 2018,but ozone *** quality in BTH and the surrounding areas showed obvious seasonal characteristics,among which PM2.5,PM10,SO2,and NO2 showed a"U"type distribution from January to December,while O3 had an"inverted U"*** hourly changes in air quality revealed that peaks of PM2.5,PM10 and NO2 appeared from 8:00 to 10:00,while those for O3 appeared at 15:00–16:*** exposure characteristics of the 31 cities showed that six districts in Beijing had the highest air quality population exposure,and that exposure levels in Zhengzhou,Puyang,Anyang,Jincheng were higher than the average of the 31 investigated ***,multiple linear regression revealed a negative correlation between meteorological factors(especially wind and precipitation)and air quality,while a positive correlation existed between industrial pollution emissions and air quality in most of BTH and its surrounding cities.

关键词： Beijing–Tianjin–Hebei Air quality population exposure Seasonal index Hourly change Industrial pollution source emission Meteorology factors