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Acta Mechanica Sinica 2008年第1期24卷 69-82页

作者： jing tang Xing School of Engineering Sciences University of Southampton Southampton SO17 1B J England

A fluid-structure interaction system subject to Sommerfeld＇s condition is defined as a Sommerfeld system which is divided into three categories： Fluid Sommerfeld （FS） System, Solid Sommerfeld （SS） System and Fluid Solid Sommerfeld （FSS） System of which Sommerfeld conditions are imposed on a fluid boundary only, a solid boundary only and both fluid and solid boundaries, respectively. This paper follows the previous initial results claimed by simple examples to further mathematically investigate the natural vibrations of generalized Sommerfeld systems. A new parameter representing the speed of radiation wave for generalized 3-D problems with more complicated boundary conditions is introduced into the Sommerfeld condition which allows investigation of the natural vibrations of a Sommerfeld system involving both free surface and compressible waves. The mathematical demonstrations and selected examples confirm and reveal the natural behaviour of generalized Sommerfeld systems defined above. These generalized conclusions can be used in theoretical or engineering analysis of the vibrations of various Sommerfeld systems in engineering.

关键词： Sommerfeld system Complex natural frequencies Fluid-structure interaction Complex energyflow identity Speed of radiation wave

Theoretical investigations on lattice Boltzmann method:an amended MBD and improved LBM

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Acta Mechanica Sinica 2021年第11期37卷 1659-1682,I0002页

作者： jing tang Xing Maritime Engineering School of EngineeringFEPSUniversity of SouthamptonSouthamptonSO171BJUK

This paper presents theoretical investigations of lattice Boltzmann method(LBM)to develop a completed LBM *** on H-theorem with Lagrangian multiplier method,an amended theoretical equilibrium distribution function(EDF)is derived,which modifies the current Maxwell–Boltzmann distribution(MBD)to include the total internal energy as its *** modification allows the three conservation laws derived directly from lattice Boltzmann equation(LBE)without additional small-parameter expansions adopted in *** this amended theoretical EDF,an improved LBM is developed,in which the total internal energy like the mass density and mean velocity is a new macroscopic variable to be updated for different times and cells during *** developed method provides a means to consider external forces and energy generation sources as generalised forces in LBM *** corresponding model and implementation process of the improved LBM are presented with its performance theoretically *** hand-workable examples are given to illustrate its applications and to confirm its *** paper will excite more researchers and scientists of this area to numerically practice the new theory and method dealing with complex physical problems,from which it is expected to further advance LBM benefiting science and engineering.

关键词： Amended MBD Improved LBM Macroscopic internal energy Conservation laws from LBE Lagrangian multiplier method

Generalised energy conservation law for chaotic phenomena

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Acta Mechanica Sinica 2019年第6期35卷 1257-1268页

作者： jing-tang Xing Faculty of Engineering and Physical Sciences University of SouthamptonSouthampton SO171BJUK

Chaotic phenomena are increasingly being observed in all fields of nature,where investigations reveal that a natural phe nomenon exhibits nonlinearities and attempts to reveal their deep underlying *** is normally understood as“a state of disorder”,for which there is as yet no universally accepted mathematical definition.A commonly used concept states that,for a dynamical system to be classified as chaotic,it must have the following properties:be sensitive to initial conditions,show topological transitivity,have densely periodical orbits *** the rules that govern chaotic motion is thus an important unsolved task for exploring nature.W e present herein a generalised energy conservation law governing chaotic *** on two scalar variables,*** potential and kinetic energies defined in the phase space describing nonlinear dynamical systems,we find that chaotic motion is periodic motion with infinite time period whose time-averaged generalised potential and kinetic energies are conserved over its time *** implies that,as the averaging time is increased,the time-averaged generalised potential and kinetic energies tend to constants while the time-averaged energy flows,i.e.,their rates of change with time,tend to *** simulations on reported chaotic motions,such as the forced van der Pol system,forced Duffing system,forced smooth and discontinuous oscillator,Lorenz’s system,and Rossler's system,show the above conclusions to be correct according to the results presented *** discovery may indicate that chaotic phenomena in nature could be controlled because,even though their instantaneous states are disordered,their long-time averages can be predicted.

关键词： Chaos Generalised energy Generalised energy conservation Nonlinear dynamical systems Energy flow theory

New model for load-sharing k-out-of-n:G system with different components

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Journal of Systems Engineering and Electronics 2008年第4期19卷 748-751,842页

作者： tang Yinghui Zhang jing School of Mathematics & Software Science Sichuan Normal Univ. Chengdu 610066 P. R. China

On the basis of capacity flow model, a new model is developed for a load-sharing k-out-of-n： G system consisting of different components, to describe the increase of the same component＇s failure rates under different loads. All components have exponential life distributions and are nonrepairable in the system. Reliability of load- sharing 2-out- of-3： G system is calculated and some special cases for the system are discussed. The calculation and discussions show that the model is right and practical.

关键词： load-sharing k-out-of-n: G system system reliability

Research progress in human infection with avian influenza H7N9 virus

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Science China(Life Sciences) 2017年第12期60卷 1299-1306页

作者： jing tang Dayan Wang National Institute for Viral Disease Control and Prevention Chinese Center for Disease Control and Prevention WHO Collaborating Center for Reference and Research on Influenza Key Laboratory for Medical Virology National Health and Family Planning CommissionBeijing 102206China

Since the identification of the novel reassortant avian influenza A(H7N9) virus in China in 2013, until Jun 30, 2017, the virus has caused five epidemic waves leading to a total of 1,552 human infections, with a fatality rate of about 40%. In the spring of2017, highly pathogenic avian influenza(HPAI) H7N9 virus emerged and has caused 25 human infections. The HPAI H7N9 virus has some biological differences from the LPAI one, such as its multiple basic amino acid residues on HA leading to its independence on trypsin for replication. The pathogenicity of the HPAI H7N9 virus to experimental animals or humans is still unclear. A(H7N9) vaccine development for pandemic preparedness is ongoing, including the reassortment(H7N9/PR8)reverse genetic based vaccine, the virus like particle(VLP) vaccine, the intranasal live attenuated influenza vaccine(LAIV),the non-adjuvant Vero cell culture-derived inactivated whole-virus vaccine, the MDCK culture-derived vaccine, the H7 DNA vaccine and the recombinant replicative H7N9 virus \(H7N9-53 TM\) vaccine. Five neuramidinase resistant sites of A(H7N9)virus isolated from patients have been reported. Some alternative drugs have been studied, such as DAS181(Fludase), ribavirin,troglitazone and minocycline. Persistent surveillance and enhanced global control are essential to fight against human infections with A(H7N9) virus.

关键词： influenza A(H7N9) virus epidemiology virological characteristics vaccine drug resistance

Thermodynamic analysis on the formation mechanism of MgO·Al_2O_3 spinel type inclusions in casing steel

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International Journal of Minerals,Metallurgy and Materials 2010年第1期17卷 32-38页

作者： Hai-yan tang jing-she Li School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing 100083 China

MgO·Al2O3 spinel type inclusions in casing steel were analyzed by scanning electron microscope （SEM） and energy dispersive spectrometer （EDS）. The results show that there are three forms. One is pure MgO·Al2O3 spinel, another is the composite oxide of the Mg-Al-Ca-Si-O system, and the third is the complex with oxide as a core covered by sulfide. The formation mechanisms were studied. The influences of slag basicity and vacuum degree on the magnesium content during the vacuum treatment of molten steel and furnace lining in molten steel were calculated with the coexistence theory of slag structure. The results show that the magnesium content increases with the increase in slag basicity and aluminum content in molten steel, and decreases with the increase in CO partial pressure.

关键词： magnesium-aluminum spinel basicity theoretical model formation mechanism

Energy flow characteristics of friction-induced nonlinear vibrations in a water-lubricated bearing-shaft coupled system

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Acta Mechanica Sinica 2021年第4期37卷 679-704,I0003页

作者： Li Qin Hongling Qin jing tang Xing Key Laboratory of Metallurgical Equipment and Control Technology School of Machinery&AutomationWuhan University of Science and TechnologyWuhan 430081China Hubei Key Laboratory of Hydroelectric Machinery Design&Maintenance Three Gorges UniversityYichang 443002China Maritime Engineering Group CMEESchool of EngineeringFaculty of Engineering&Physical SciencesUniversity of SouthamptonSouthampton SO 171BJUK

Based on the energy flow theory of nonlinear dynamical system,the stabilities,bifurcations,possible periodical/chaotic motions of nonlinear water-lubricated bearing-shaft coupled systems are investigated in this *** is revealed that the energy flow characteristics around the equlibrium point of system behaving in the three types with different friction-para-mters.(a)Energy flow matrix has two negative and one positive energy flow factors,constructing an attractive local zero-energy flow surface,in which free vibrations by initial disturbances show damped modulated oscillations with the system tending its equlibrium state,while forced vibrations by external forces show stable oscillations,(b)Energy flow matrix has one negative and two positive energy flow factors,spaning a divergence local zero-energy flow surface,so that the both free and forced vibrations are divergence oscillations with the system being unstable,(c)Energy flow matrix has a zero-energy flow factor and two opposite factors,which constructes a local zero-energy flow surface dividing the local phase space into stable,unstable and central subspace,and the simulation shows friction self-induced unstable vibrations for both free and forced *** a set of friction parameters,the system behaves a periodical oscillation,where the bearing motion tends zero and the shaft motion reaches a stable limit circle in phase space with the instant energy flow tending a constant and the time averaged one tending *** simulations have not found any possible chaotic motions of the *** is discovered that the damping matrices of cases(a),(b)and(c)respectively have positive,negative and zero diagonal elements,resulting in the different dynamic behavour of system,which gives a giderline to design the water-lubricated bearing unit with expected performance by adjusting the friction parameters for applications.

关键词： Nonlinear friction-induced vibrations Nonlinear energy flows Nonlinear water-lubricated bearing-shaft systems Bifucation friction parameters Energy flow matrices Periodical oscilation

A Molecular Hepatocellular Carcinoma Prognostic Score System Precisely Predicts Overall Survival of Hepatocellular Carcinoma Patients

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Journal of Clinical and Translational Hepatology 2022年第2期10卷 273-283页

作者： Jie Jia jing tang Department of Orthopedics Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWu-hanHubeiChina Cancer Center Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhanHubeiChina

Background and Aims:With high rates of recurrence post-treatment,hepatocellular carcinoma(HCC)is one of the most common types of cancer worldwide and the major cause of cancer *** improve the overall survival of HCC patients,identification of a reliable biomarker and precise early diagnosis of HCC remain major unsolved ***:We initially screened data from the Cancer Genome Atlas liver cancer cohort to identify potential prognosis-related ***,a metaanalysis of five international HCC cohorts was implemented to validate such ***,artificial intelligence models(random forest and neural network)were trained to predict prognosis accurately,and a log-rank test was performed for ***,the correlation between the molecular hepatocellular carcinoma prognostic score(mHPS)and the stromal and immune scoring in HCC were ***:A comprehensive list of 65 prognosis-related genes was obtained,most of which have been not extensively studied thus far.A universal HCC mHPS system depending on the expression pattern of only 23 genes was *** mHPS system had general applicability to HCC patients(log-rank p<0.05)in a platform-independent manner(RNA sequencing or microarray).The mHPS was also correlated with the stromal and immune scoring in HCC,reflecting the status of the tumor immune ***:Overall,the mHPS is an easy and cost-effective prognosis predicting system,which can disclose previously uncovered heterogeneity among patient *** mHPS system can further stratify patients who are at the same clinical stage and should be valuable for precise ***,the prognosis-related genes recog-nized in this study have potential in targeted and immune therapy.

关键词： Hepatocellular carcinoma Random forest Neural network Prog-nostic scoring system Personalized medicine

Phase noise approximation analysis for the OFDM system

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The Journal of China Universities of Posts and Telecommunications 2007年第3期14卷 95-98,107页

作者： tang jing SHEN Shu-qun Wireless Technique Innovation Institute Key Laboratory of UniversalWireless Communication Ministry of Education Beijing University of Postsand Telecommunications Beijing 100876 China

The influence of phase noise（PN） present at the access point（AP） and mobile terminator（MT） may degrade the performance in orthogonal frequency division multiplexing （OFDM） system, because the OFDM system is sensitive to the PN. The method of PN approximation based on the PN power spectrum was proposed to combat the influence of the PN present. The idea of the PN cancellation is the PN is approximated for the sum of the different frequency between the AP and the MT as well as Doppler shift supposing that the fixed different frequency during several OFDM symbols are identical, so the variable phase may be considered as the combination of the fixed partition and the random partition. The approximation method is utilized to remove the fixed and the random phase partition so that the signal-to-noise ratio （SNR） may be improved. The analysis and the simtilation proposed show that the method may effectively improve the performance of the OFDM system.

关键词： inter-carrier interference(ICI) phase noise cancellation common phase error (CPE)

Crystallization behavior of plasma-sprayed lanthanide magnesium hexaaluminate coatings

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International Journal of Minerals,Metallurgy and Materials 2014年第12期21卷 1247-1253页

作者： Liang-liang Huang Hui-min Meng jing tang Corrosion and Protection Center University of Science and Technology Beijing

LaMgAl11O19 thermal barrier coatings （TBCs） were prepared by atmospheric plasma spraying. The crystallization behavior of the coatings and the synthesis mechanism of LaMgAl11O19 powders were researched. The results showed that the plasma-sprayed coatings conmined some amorphous phase, and LaMgAl11O19 powders were partially decomposed into Al2O3, LaAlO3, and MgAl2O4 in the plasma spraying process. The amorphous phase was reerystallized at a temperature of approximately 1174.9℃, at which level the decomposed Al2O3, LaAl2O3, and MgAl2O4 reacted again. The resynthesis temperature of LaMgAl11O19 in the plasma-sprayed coatings was lower than that of LaMgAl11O19 in the original raw powders. The synthesis mechanism of LaMgAl11O19 powders can be summarized as follows： during the first part of the overall reaction, La2O3 reacts with Al2O3 to form LaAl2O3 at approximately 900℃, and then LaAl2O3 further reacts with Al2O3 and MgAl2O4 to produce LaMgAl11O19 at approximately 1200℃.

关键词： thermal barrier coatings hexaaluminates plasma spraying crystallization