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TRAVELING WAVES IN A SIRH MODEL WITH SPATIO-TEMPORAL DELAY AND NONLOCAL DISPERSAL

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Acta Mathematica Scientia 2022年第2期42卷 715-736页

作者： Lu YANG Yun-Rui YANG xue song School of Mathematics and Physics Lanzhou Jiaotong UniversityLanzhou 730070China

This paper deals mainly with the existence and asymptotic behavior of traveling waves in a SIRH model with spatio-temporal delay and nonlocal dispersal based on Schauder’s fixed-point theorem and analysis techniques,which generalize the results of nonlocal SIRH models without relapse and *** particular,the difficulty of obtaining the asymptotic behavior of traveling waves for the appearance of spatio-temporal delay is overcome by the use of integral techniques and analysis ***,the more general nonexistence result of traveling waves is also included.

关键词： Nonlocal dispersal spatio-temporal delay traveling waves

Comparison of Grain Size in Plain Carbon Hot-Rolled Sheets Manufactured by CSP and Conventional Rolling Processing

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Journal of Iron and Steel Research International 2012年第1期19卷 17-22页

作者： ZHU xue-song ZHU Guo-hui MAO Wei-min School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China School of Materials Science and Engineering Anhui University of Technology Ma＇anshan 243002 Anhui China

Average grain size and grain size distribution in as hot-rolled SPHC, SPHD, and SPHE sheets manufac- tured by compact strip production （CSP） processing and traditional continuous casting and rolling （CCR） processing respectively were investigated by quantitative metallographic method. The results show that the average grain size and distribution width of grain size in sheets manufactured by CSP processing was obviously larger than that by CCR processing. It was analyzed that multi-phase transformation and high reduction ratio in CCR processing resulted in refining grain size, which would be dominant reason for controlling grain size. In plain carbon steels such as SPHC, SPHD and SPHE, the effect of fine precipitation in CSP on behavior of deformation and recrystallization of austenite during roiling, and consequent refinement of grain size seem not to be as important as the effect of reheating and roughing in CCR processing. Homogenizing in reheating and refining grain size in roughing in CCR processing would refine final grain size and also make grain size homogenized, Very coarse grain size would result in mixed grain size, large distribution width of grain size due to interaction of static and dynamic recrystallization in CSP processing

关键词： CSP CCR hot-rolled plate grain size

Trace Formulae of Characteristic Polynomial and Cayley-HamUton's Theorem, and Applications to Chiral Perturbation Theory and General Relativity

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Communications in Theoretical Physics 2008年第4期49卷 801-808页

作者： ZHANG Hong-Hao YAN Wen-Bin LI xue-song School of Physics and Engineering Sun Yat-Sen University Guangzhou 510275 China Department of Physics Tsinghua University Beijing 100084 China Science College Hunan Agricultural University Changsha 410128 China Department of Physics and Astronomy Satte University of New York at Stony Brook New York 11794 USA

By using combinatorics, we give a new proof for the recurrence relations of the characteristic polynomial coefficients, and we further obtain an explicit expression for the generic term of the coefficient sequence, which yields the trace formulae of the Cayley-Hamilton＇s theorem with all coefficients explicitly given. This implies a byproduct, a complete expression for the determinant of any finite-dimensional matrix in terms of the traces of its successive powers. And we discuss some of their applications to ehiral perturbation theory and general relativity.

关键词： characteristic polynomial coefficients Cayley-Hamilton's theorem chiral perturbation theory general relativity

Adaptability of microbial inoculators and their contribution to degradation of mineral oil and PAHs

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Journal of Environmental Sciences 2006年第2期18卷 310-317页

作者： song xue-ying song Yu-fang SUN Tie-heng ZHOU Qi-xing ZHANG Wei ZHANG Lei Key Laboratory of Terrestrial Ecological Process Institute of Applied Ecology Chinese Academy of Sciences Shenyang 110016 China Graduate School of Chinese Academy of Sciences Beijing 100039 China Key Laboratory of Environmental Engineering Shenyang University Shenyang 100041 China Institute of Microbiology Chinese Academy of Sciences Beijing 100081 China

Five dominant bacteria strains（A cetobacter sp., Alcdigenes sp., Micrococcus sp., Arthrobacter sp. and Bacillus sp.） and five fungi strains （Cephalosporium sp. Ⅰ, Cephalosporlum sp. Ⅱ, Aspergillus sp. Ⅰ, Aspergillus sp. Ⅱ and Fusarium sp.） isolated from petroleum-contaminated soil were used to assess the potential capability of mineral oil and PAH enhanced degradation separately and jointly using the batch liquid medium cultivation with diesel oil spiked at 1000 mg/L. The experiment was performed on a reciprocal shaker in the darkness at 25℃ to 30℃ for 100 d. The dynamic variation in the activity of microbial inoculators in each treatment and the degradation of the target pollutants during the period of experiment were monitored. Results showed a more rapid biodegradation of mineral oil and PAHs at the beginning of the experiment （about 20 d） by dominant bacteria, fungi and their mixture than that of the indigenous microorganisms, however, thereafter an opposite trcnd was exhibited that the removal ratio by indigenous microorganisms was superior to any other dominant treatments and the tendency lasted till the end of the experiment, indicating the limited competitive capability of dominant microorganisms to degrade the contaminants, and the natural selection of indigenous microorganisms for use in the removal of the contaminants. At the end of the experiment, the removal ratio of mineral oil ranged from 56.8 % to 79.2 % and PAHs ranged from 96.8 % to 99.1% in each treatment by microbial inoculators,

关键词： dominant microorganism indigenous microorganism mineral oil PAHs biodegradation

Microstructure and mechanical properties of Mg-6Zn-0.5Y magnesium alloy prepared with ultrasonic treatment

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Rare Metals 2017年第8期36卷 622-626页

作者： Di Li Han-song xue Gang Yang Ding-Fei Zhang College of Materials Science and Engineering Chongqing UniversityChongqing 400044China National Engineering Research Center for Magnesium Alloys Chongqing UniversityChongqing 400044China

Ultrasonic effect on microstructure evolution and mechanical properties of Mg-6Zn-0.5Y magnesium alloy was *** results show that ultrasonic treatment can significantly modify the as-cast microstructure of Mg-6Zn-0.5Y *** the application of ultrasonic treatment,the primary a-Mg phase transforms from coarse dendrites to nearly fine equiaxed grains,and the continuous I-phase atα-Mg boundaries is modified into discontinuous ***,the area fraction of I-phase decreases after ultrasonic ***,the tensile properties of Mg-6Zn-0.5Y alloy are apparently improved after ultrasonic *** to those of the untreated alloy,the ultimate tensile strength and elongation of Mg-6Zn-0.5Y alloy are improved by 67%and 56%,respectively.

关键词： Magnesium alloy Ultrasonic treatment Microstructure Mechanical properties

Study on the subgrade deformation under high-speed train loading and water–soil interaction

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Acta Mechanica Sinica 2016年第2期32卷 233-243页

作者： Jian Han Guo-Tang Zhao Xiao-Zhen Sheng xue-song Jin State Key Laboratory of Traction Power Southwest Jiaotong University Chengdu 610031 China China Railway Corporation Beijing 100844 China

It is important to study the subgrade characteristics of high-speed railways in consideration of the water–soil coupling dynamic problem,especially when high-speed trains operate in rainy *** study develops a nonlinear water–soil interaction dynamic model of slab track coupling with subgrade under high-speed train loading based on vehicle–track coupling *** using this model,the basic dynamic characteristics,including water–soil interaction and without water induced by the high-speed train loading,are *** main factors-the permeability coefficien and the porosity-influencin the subgrade deformation are *** developed model can characterize the soil dynamic behaviour more realistically,especially when considering the influenc of water-rich soil.

关键词： Water–soil interaction High-speed train loading Finite difference method Subgrade deformation Permeability coefficien Porosity

Diffusion Dynamics of Cux Cluster on Cu（111） Surface

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Chinese Journal of Chemical Physics 2008年第1期21卷 27-31页

作者： Jian-feng Tang Mai-chang Xu xue-song Li Wo-yun Long Department of Applied Physics Hunan Agricultural University Changsha 410128 China Department of Maths and Physics Hunan Institute of Engineering Xiangtan 411104 China

The diffusion dynamics of small two-dimensional atomic clusters Cux （1≤x≤8） on Cu（lll） surface were studied using the molecular dynamics simulations and a modified analytic embedded-atom method in the temperature range from 200 K to 800 K. The cluster size and temperature dependence of the diffusion coefficients and migration energies are presented. Our simulations show that the diffusion migration energy of the CuT cluster is the highest and the prefactor for the CuT cluster is almost three orders of magnitude larger than that for single atom diffusion. This conclusion is consistent with the experimental results for similar metals. In addition, the dependence of cluster diffusion on film growth is also discussed.

关键词： Cluster Molecular dynamics Surface diffusion

Subcutaneous panniculitis-like T-cell lymphoma invading central nervous system in long-term clinical remission with lenalidomide:A case report

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World Journal of Clinical Cases 2021年第8期9卷 1885-1892页

作者： Jing Sun Xiao-Shan Ma Li-Mei Qu xue-song song Department of Anesthesiology The First Hospital of Jilin UniversityChangchun 130021Jilin ProvinceChina Department of Neurosurgery The First Hospital of Jilin UniversityChangchun 130021Jilin ProvinceChina Department of Pathology The First Hospital of Jilin UniversityChangchun 130021Jilin ProvinceChina

BACKGROUND Subcutaneous panniculitis-like T-cell lymphoma(SPTCL)involvement in the central nervous system(CNS)is particularly *** with CNS involvement has an exceedingly poor prognosis,and no optimum therapeutic method has been *** the best of our knowledge,this is the first reported case of SPTCL invading the CNS achieving long-term remission with lenalidomide maintenance *** SUMMARY A 63-year-old man diagnosed with SPTCL was admitted to the hospital with severe headache for 15 d after four cycles of *** to the treatment,the patient developed CNS *** biopsy was pathologically diagnosed as CNS T-cell lymphoma,and two courses of chemotherapy were performed *** to the intolerance of the side effects of chemotherapeutic drugs,the patient received lenalidomide *** magnetic resonance imaging of the head at the 8 mo follow-up indicated no signs of recurrence,and the vital signs were *** Lenalidomide deserves further investigation as a targeted drug for SPTCL cases involving the CNS.

关键词： Subcutaneous panniculitis-like T-cell lymphoma Central nervous system Tcell lymphoma Lenalidomide Complication Case report

Ballistic penetration damages of hybrid plain-woven laminates with carbon,Kevlar and UHMWPE fibers in different stacking sequences

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Defence Technology（防务技术） 2023年第8期26卷 23-38页

作者： Zhi-yong Li You-song xue Bao-zhong Sun Bo-hong Gu Shanghai Frontier Science Research Center for Modern Textiles College of TextilesDonghua UniversityShanghai201620China

Hybrid composite materials combine different fibers in preform and take advantages of different mechanical behaviors for improving ballistic impact damage *** we report ballistic impact damages of plain-woven laminates with different hybrids and stacking *** kinds of hybrid laminates,i.e.,carbon/Kevlar,carbon/ultra-high molecular weight polyethylene(UHMWPE),and UHMWPE/Kevlar,had been prepared and tested in ballistic penetration with fragment simulating projectiles(FSP).The residual velocities of the projectiles and impact damage morphologies of the laminates have been obtained to show impact energy absorptions for the different hybrid schemes.A microstructural model of the hybrid laminates had also been established to show impact damage mechanisms with finite element analysis(FEA).We found that the UHMWPE/Kevlar hybrid laminates with Kevlar layers as the front face have the highest energy absorption capacity,followed by the carbon/Kevlar hybrid laminates with carbon layers as the front *** main damage modes are fiber breakages,matrix crack and interlayer *** ballistic damage evolutions from the FEA results show that the major damage is shear failure for front layers,while tension failure for the back *** expect that the ballistic impact performance could be improved from the different hybrid schemes.

关键词： Hybrid laminates Ballistic impact damages Energy absorption Finite element analysis(FEA)