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Reflection of Shock Fronts in a van der Waals Fluid

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Chinese Annals of Mathematics,Series B 2013年第6期34卷 927-956页

作者： shuyi zhang Yaguang WANG Business Information Management School Shanghai University of International Business and Economics Department of Mathematics Shanghai Jiao Tong University

In this paper,the reflection phenomenon of a vapor shock front(both sides of the front are in the vapor phase)in a van der Waals fluid is *** the1-dimensional case and the multidimensional case are *** authors find that under certain conditions,the reflected wave can be a single shock,or a single subsonic phase boundary,or one weak shock together with one subsonic phase boundary,which depends on the strength of the incident *** is different from the known result for the reflection of shock fronts in a gas dynamical system due to Chen in 1989.

关键词： Shock Subsonic phase boundary Reflection Boundary value problem

Two-stage identification of interlayer contact loss for CRTS Ⅲ prefabricated slab track based on multi-index fusion

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2023年第6期24卷 497-515页

作者： Wei DU Juanjuan REN Kaiyao zhang Shijie DENG shuyi zhang MOE Key Laboratory of High-Speed Railway Engineering School of Civil EngineeringSouthwest Jiaotong UniversityChengdu 610031China

To accurately identify the potential contact loss of the China railway track system(CRTS)III prefabricated slab track,a finite element model with contact loss of self-compacting concrete(SCC)under transient impact was *** the vertical accelerations near impact points on the track slab surface were extracted to obtain damage-sensitive indices in the time and frequency *** indices were initially normalized to obtain independent items of evidence before the Dempster-Shafer(D-S)evidence theory was used to fuse these into ***,a two-stage identification was performed to identify the damaged SCC area,comprising a rough identification(Stage I)and a precise identification(Stage II).The research results show that the damage indices extracted based on the transient impact response change abruptly at the damage location,and that can be used for damage ***,the use of a single index to determine the damage of the impact point may be *** Stage I,five damage indices of acceleration were fused to magnify the difference between the damaged point and undamaged point,thereby improving the accuracy of finding *** Stage II,in the area where more impact points were added,a fusion of three indices of acceleration response,that is,the absolute mean of the time domain,the maximum amplitude of the frequency domain,and the power density ratio,further narrowed down the area where damage *** a result,when the contact loss of SCC is greater than 50%along the thickness direction,the identification accuracy can be as high as 70%to 80%.The two-stage identification method proposed in this study can greatly improve the efficiency of interlayer damage detection of slab tracks and is expected to provide effective technical support for damage identification of track structures in the future.

关键词： Slab track Contact loss identification Transient impact response Index fusion Dempster-Shafer(D-S)evidence theory

Laser-enhanced thermal effect of moderate intensity focused ultrasound on bio-tissues

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Science China(Physics,Mechanics & Astronomy) 2017年第9期60卷 28-36页

作者： JinYu Zhao shuyi zhang XiuJi Shui Li Fan Laboratory of Modern Acoustics Institute of Acoustics Collaborative Innovation Center of Advanced Microstructures Nanjing University

For avoiding extra-damage to healthy tissues surrounding the focal point during high intensity focused ultrasound(HIFU) treatment in medical therapy, to reduce the ultrasonic intensity outside the focal point is expected. Thus, the heating processes induced by moderate intensity focused ultrasound(MIFU) and enhanced by combined irradiation of laser pulses for bio-tissues are studied in details. For fresh bio-tissues, the enhanced thermal effects by pulsed laser combined with MIFU irradiation are observed experimentally. To explore the mechanisms of these effects, several tissue-mimicking materials composed of agar mixed with graphite powders are prepared and studied for comparison, but the laser-enhanced thermal effects in these mimicking materials are much less than that in the fresh bio-tissues. Therefore, it is suggested that the laser-enhanced thermal effects may be mainly attributed to bio-activities and related photo-bio-chemical effects of fresh tissues.

关键词： bio-tissue focused ultrasound laser pulse irradiation thermal effect

REFLECTIVE CHARACTERISTICS OF SAW BY SLANTING METAL STRIP ARRAYS

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Chinese Journal of Acoustics 1989年第1期8卷 20-32页

作者： zhang, Bufa zhang, shuyi Wei, Rongjue Nanjing Univ China

The reflective characteristics of SAW by slanting metal strips on the surface of YZ - LiNbO3 have been studied. By using both Simple Model and Multi - Reflection Model, the reflective characteristics of SAW by a periodic metal strip array and the SAW distribution in the array have been calculated. Furthermore, by using an improved laser probe, the reflective SAW field by the array has also been measured. By comparing the theoretical results with the experiments, it is shown that the results of Multi - Reflection Model, being more exact than the simple one, are in better agreement with the experiment.

关键词： Acoustic Waves Reflection Sheet and Strip Metal Acoustic Properties

Differential introgression suggests candidate beneficial and barrier loci between two parapatric subspecies of Pearson＇s horseshoe bat Rhinolophus pearsoni

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Current Zoology 2016年第4期62卷 405-412页

作者： Xiuguang MAO shuyi zhang Stephen J. ROSSlTER Institute of Estuarine and Coastal Research East China Normal University Shanghai 200062 China School of Biological and Chemical Sciences Queen Mary University of London London E14NS UK

Observations that rates of introgression between taxa can vary across loci are increasingly common. Here, we test for differential locus-wise introgression in 2 parapatric subspecies of Pearson＇s horseshoe bat （Rhinolophus pearsoni chinensis and R. p. pearsoni）. To efficiently identify putative speciation genes and/or beneficial genes in our current system, we used a candidate gene approach by including loci from X chromosome that are suggested to be more likely involved in reproductive isolation in other organisms and loci underlying hearing that have been suggested to spread across the hybrid zone in another congeneric species. Phylogenetic and coalescent analyses were performed at 2 X-linked, 4 hearing genes, as well as 2 other autosomal loci individually. Likelihood ratio tests could not reject the model of zero gene flow at 2 X-linked and 2 autosomal genes. In contrast, gene flow was supported at 3 of 4 hearing genes. While this introgression could be adaptive, we cannot rule out stochastic processes. Our results highlight the utility of the candidate gene approach in searching for speciation genes and/or beneficial genes across the species boundary in natural populations.

关键词： gene flow hybridization hybrid zone reproductive isolation.

Characteristics of surface acoustic waves in (1120) ZnO film/R-sapphire substrate structures

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Science China(Physics,Mechanics & Astronomy) 2018年第2期61卷 41-48页

作者： Yan Wang shuyi zhang Jing Xu YingCai Xie XiaoDong Lan School of Electronic Science and Engineering Nanjing University of Posts and Telecommunications Lab of Modern Acoustics Institute of Acoustics Nanjing University

（1120）ZnO film/R-sapphire substrate structure is promising for high frequency acoustic wave devices. The propagation characteristics of SAWs, including the Rayleigh waves along [0001] direction and Love waves along [1100] direction, are investigated by using 3 dimensional finite element method （3D-FEM）. The phase velocity （vp）, electromechanical coupling coefficient （k2）, temperature coefficient of frequency （TCF） and reflection coefficient （r） of Rayleigh wave and Love wave devices are theoretically analyzed. Furthermore, the influences of ZnO films with different crystal orientation on SAW properties are also investigated. The results show that the 1st Rayleigh wave has an exceedingly large/d of 4.95% in （90°, 90°, 0°）（1120）ZnO film/R-sapphire substrate associated with a phase velocity of 5300 m/s; and the 0th Love wave in （0°, 90°, 0°）（1120）ZnO film/R-sapphire substrate has a maximum k2 of 3.86% associated with a phase velocity of 3400 m/s. And （1120）ZnO film/R-sapphire substrate structures can be used to design temperature-compensated and wide-band SAW devices. All of the results indicate that the performances of SAW devices can be optimized by suitably selecting ZnO films with different thickness and crystal orientations deposited on R-sapphire substrates.

关键词： surface acoustic wave (1120)ZnO films R-sapphire finite element method

Preface to the Special Topic on Modern Acoustics

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Science China(Physics,Mechanics & Astronomy) 2013年第7期56卷 1235-1236页

作者： zhang shuyi QIU XiaoJun LIU XiaoZhou Key Laboratory of Modern Acoustics Institute of AcousticsNanjing University

The 9^th International Symposium on Modem Acoustics was held in Nanjing, China, on May 19-22, 2012. In 1985, Prof. WEIRongJue, the pioneer and founder of the Institute of-Acoustics of N-anjing University, Member of Chinese Academy of Sciences, organized the First International Workshop on Modern Acoustics. By the end of last century,

关键词：近代声学国际研讨会中国社科院专题调制解调器声学研究所开拓者实验室

Energy-saving PPM schemes for WSNs

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Science in China(Series F) 2008年第5期51卷 571-585页

作者： TANG QiuLing YANG LiuQing QIN TuanFa zhang shuyi School of Computer Electronics and Information Guangxi University Nanning 530004 China Department of Electrical and Computer Engineering University of Florida P. O. Box 116130 Gainesville FL 32611 USA Lab of Modern Acoustics Nanjing University Nanjing 210093 China

Energy conservation is a critical problem in recently-emerging wireless sensor networks （WSNs）. Pulse position modulation （PPM）, as an exploring-worthy modulation format for energy efficiency, is tailored for WSNs into two schemes, mono-mode PPM and multi-mode PPM, in this paper. Resorting to an idealized system model and a practical system model, which combine the power consumptions in transmission and reception modules of nodes with the idealized and real- istic battery characteristics, the battery energy efficiencies of mono-mode PPM and multi-mode PPM are evaluated and compared. To minimize the battery energy consumption （BEC）, these schemes are further optimized in terms of constellation size M for a link in path-loss channels. Our analytical and numerical results show that considerable energy can be saved by multi-mode PPM; and the optimization performances of these schemes are noticeable at various communication distances though their optimization properties are different.

关键词： wireless sensor networks (WSNs) mono-mode PPM multi-mode PPM battery energy consumption (BEC),parameter optimization

Fruit bats as anatural reservoir of zoonotic viruses

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Chinese Science Bulletin 2003年第2期48卷 1179-1182页

作者： JIA Guangle zhang Ying WU Tinghe zhang shuyi WANG Yinan Institute of Zoology Chinese Academy of SciencesBeijing 100080China Shanxi Agricultural University Taigu 030801China

As a natural reservoir of manifold zoonotic viruses, fruit bats have been involved in at least three emerging zoonoses in recent years. This paper aims to intro-duce the epidemiological characteristics of these diseases emerged in the Australasian region between 1994 and 1999, transmission pathways of the newly discovered viruses and the relationship between the changed entironment of fruit bats and occurrences of these emerging diseases and provide a clue for the epidemiological investigations of SARS.

关键词： fruit bat natural reservoir zoonotic virus.