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Conformally Mapped Multifunctional Acoustic Metamaterial Lens for Spectral Sound Guiding and Talbot Effect

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Research 2019年第1期2019卷 299-308页

作者： He Gao Xinsheng Fang Zhongming Gu tuo liu Shanjun Liang Yong Li Jie Zhu Department of Mechanical Engineering The Hong Kong Polytechnic UniversityHung HomKowloonHong Kong SARChina Institute of Acoustics School of Physics Science and EngineeringTongji UniversityShanghai 200092China The Hong Kong Polytechnic University Shenzhen Research Institute Shenzhen 518057China

We demonstrate a conformally mapped multifunctional acoustic metamaterial Mikaelian *** lens is a gradient medium with a hyperbolic secant refractive index profile that can realize functions like beam *** the conventional design approaches,with a conformal transformation method,only isotropic material parameters with gradient refractive index profiles are required for the construction of such *** realize desired gradient index distribution,we carefully design a new type of crosschannel-shaped acoustic metamaterial,whose refractive index can be effectively modulated by simply changing the slit opening *** distinct capabilities of the metamaterial Mikaelian lens in manipulating acoustic waves are experimentally verified with the fabricated *** sound guiding and Talbot effects,which normally require respective geometrical and wave acoustic approximations,are observed in simulations and ***,those effects of shaping acoustic wave propagations were validated within a relatively wide frequency *** study reveals how the conformal transformation method can help to bridge the ray acoustics with wave *** offers opportunities to the development of novel multifunctional acoustic devices for various applications,such as sound and particle manipulations.

关键词： Talbot acoustics refractive

Analysis of the Reliability Model of the Tool Magazine Subsystem in the Processing Center

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Journal of Electronic Research and Application 2021年第1期5卷 12-19页

作者： tuo liu University of Washington Seattle USA

Tool magazine is an important part of a processing *** magazines have the advantage of reducing work parts turnover,handling,and storage *** addition,some research shows that the use of tool magazine in machine tools in the machining center can make the cutting time utilization rate of machine tools 3-4 times higher than that of ordinary machine tools,and has better machining consistency,thus improving processing accuracy and processing efficiency,shortening the production ***,the reliability,efficiency and accuracy of the tool magazine have a crucial impact on the stability of the machine ***,the reliability analysis of CNC machine tool magazine is considerably *** view of this problem,this paper puts forward that the reliability model of the tool magazine is established after the parameter estimation and hypothesis test,and then the maintainability model of the tool magazine is built,it ends with the fault analysis of the tool magazine.

关键词： Tool Magazine Processing Center Reliability Repairability Failure Analysis

The influence of synthetic jet excitation on secondary flow in compressor cascade

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Journal of Thermal Science 2010年第6期19卷 500-504页

作者： Yanming liu, tuo SUN, Chaobin GUAN and Baoguo WANG School of Aerospace Engineering, Beijing Institute of Technology, Beijing, 100081, China Assistant Professor School of Aerospace Engineering Beijing Institute of Technology Beijing China

The detailed numerical simulation has been carried out to investigate the effect of synthetic jet excitation on the secondary flow at 5° incidence in a compressor cascade, in which the synthetic jet actuation is equipped on the suction surface. The influence of excitation position, one fixed near the trailing edge and the other fixed a little far from the trailing edge, has also been studied. The results show that unsteady disturbance of desirable synthetic jet effectively enhances the mixing of the fluid inside the separation region, which reduces the vortex intensity and the energy loss, improves the flow status in the cascade, and also suppresses velocity fluctuation near the trailing edge. Additionally, the actuation fixed near the separation region proves to be more effective and exit load distribution is more uniform due to the employment of the synthetic jet.

关键词： synthetic jet actuator compressor cascade loss velocity fluctuation

Solvent-Free Manufacturing of Lithium-Ion Battery Electrodes via Cold Plasma

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Energy & Environmental Materials 2024年第1期7卷 28-33页

作者： Zhiming Liang Tianyi Li Holden Chi Joseph Ziegelbauer Kai Sun Ming Wang Wei Zhang tuo liu Yang-Tse Cheng Zonghai Chen Xiaohong Gayden Chunmei Ban Paul M.Rady Department of Mechanical Engineering University of Colorado BoulderBoulder CO 80309USA Advanced Photon Source Argonne National LaboratoryLemont IL 60439USA Intecells Inc. Southfield MI 48084USA Department of Materials Science and Engineering Michigan Center for Materials CharacterizationUniversity of MichiganAnn Arbor MI 48109USA Department of Chemical and Materials Engineering University of KentuckyLexington KY 40506USA Department of Chemistry University of KentuckyLexington KY 40506USA Chemical Sciences and Engineering Division Argonne National LaboratoryLemont IL 60439USA

Slurry casting has been used to fabricate lithium-ion battery electrodes for decades,which involves toxic and expensive organic solvents followed by high-cost vacuum drying and electrode *** work presents a new manufacturing method using a nonthermal plasma to create inter-particle binding without using any polymeric binding materials,enabling solvent-free manufacturing electrodes with any electrochemistry of *** cold-plasma-coating technique enables fabricating electrodes with thickness(>200 pm),high mass loading(>30 mg cm^(-2)),high peel strength,and the ability to print lithium-ion batteries in an arbitrary *** crosscutting,chemistry agnostic,platform technology would increase energy density,eliminate the use of solvents,vacuum drying,and calendering processes during production,and reduce manufacturing cost for current and future cell ***,lithium iron phosphate and lithium cobalt oxide were used as examples to demonstrate the efficacy of the cold-plasma-coating *** is found that the mechanical peel strength of cold-plasma-coating-manufactured lithium iron phosphate is over an order of magnitude higher than that of slurry-casted lithium iron phosphate *** cells assembled with a graphite anode and the cold-plasma-coating-lithium iron phosphate cathode offer highly reversible cycling performance with a capacity retention of 81.6%over 500 *** the highly conductive cathode material lithium cobalt oxide,an areal capacity of 4.2 mAh cm^(-2)at 0.2 C is *** anticipate that this new,highly scalable manufacturing technique will redefine global lithium-ion battery manufacturing providing significantly reduced plant footprints and material costs.

关键词： cold plasma deposition lithium-ion battery solvent-free manufacturing

Acoustic Purcell effect induced by quasibound state in the continuum

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Fundamental Research 2024年第1期4卷 57-62页

作者： Sibo Huang Shuhuan Xie He Gao Tong Hao Shuang Zhang tuo liu Yong Li Jie Zhu Institute of Acoustics School of Physics Science and EngineeringTongji UniversityShanghai 200092China Department of Mechanical Engineering The Hong Kong Polytechnic UniversityHong Kong 999077China College of Surveying and Geo-Informatics Tongji UniversityShanghai 200092China Department of Physics The University of Hong KongHong Kong 999077China Key Laboratory of Noise and Vibration Research Institute of AcousticsChinese Academy of SciencesBeijing 100190China The Hong Kong Polytechnic University Shenzhen Research Institute Shenzhen 518057China

We study theoretically and experimentally the acoustic Purcell effect induced by quasi-bound states in the continuum(quasiBICs).A theoretical framework describing the acoustic Purcell effect of a resonant system is developed based on the system’s radiative and dissipative factors,which reveals the critical emission condition for achieving optimum Purcell *** show that the quasiBICs contribute to highly confined acoustic field and bring about greatly enhanced acoustic emission,leading to strong Purcell *** concept is demonstrated via two coupled resonators supporting a Friedrich-Wintgen quasiBIC,and the theoretical results are validated by the experiments observing emission enhancement of the sound source by nearly two orders of *** work bridges the gap between the acoustic Purcell effect and acoustic BICs essential for enhanced wave-matter interaction and acoustic emission,which may contribute to the research of high-intensity sound sources,high-quality-factor acoustic devices and nonlinear acoustics.

关键词： Acoustic Purcell effect Bound state in the continuum Mode coupling Sound emission enhancement High-quality-factor acoustic device

cDNA-AFLP analysis reveals differential gene expression in incompatible interaction between infected non-heading Chinese cabbage and Hyaloperonospora parasitica

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Horticulture Research 2016年第1期3卷 148-156页

作者： Dong Xiao Shi-tuo liu Yan-Ping Wei Dao-Yun Zhou Xi-Lin Hou Ying Li Chun-Mei Hu Horticulture Department College of HorticultureNanjing Agricultural UniversityNanjing 210095China State Key Laboratory of Crop Genetics&Germplasm Enhancement Ministry of AgricultureNanjing 210095China

Non-heading Chinese cabbage(Brassica rapa ***)is one of the main green leafy vegetables in the world,especially in China,with significant economic *** parasitica is a fungal pathogen responsible for causing downy mildew disease in Chinese cabbage,which greatly affects its *** objective of this study was to identify transcriptionally regulated genes during incompatible interactions between non-heading Chinese cabbage and *** using complementary DNA-amplified fragment length polymorphism(cDNA-AFLP).We obtained 129 reliable differential transcript-derived fragments(TDFs)in a resistant line‘Suzhou Qing’.Among them,121 upregulated TDFs displayed an expression peak at 24–48 h post inoculation(h.p.i.).Fifteen genes were further selected for validation of cDNA-AFLP expression patterns using quantitative reverse transcription *** confirmed the altered expression patterns of 13 genes(86.7%)revealed by the *** identified four TDFs related to fungal resistance among the 15 ***,comparative analysis of four TDFs between resistant line‘Suzhou Qing’and susceptible line‘Aijiao Huang’showed that transcript levels of TDF14(BcLIK1_A01)peaked at 48 *** 25.1-fold increased in the resistant line compared with the susceptible ***,transcript levels of the other three genes,TDF42(BcCAT3_A07),TDF75(BcAAE3_A06)and TDF88(BcAMT2_A05)peaked at 24,48 and 24 *** 25.1-,100-and 15.8-fold increases,*** results suggested that the resistance genes tended to transcribe at higher levels in the resistance line than in the susceptible line,which may provide resistance against pathogen *** present study might facilitate elucidating the molecular basis of the infection process and identifying candidate genes for resistance improvement of susceptible cultivars.

关键词： heading analysis interaction

Optical microcombs in whispering gallery mode crystalline resonators with dispersive intermode interactions

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Photonics Research 2022年第12期10卷 2866-2875页

作者： tuo liu SUWAN SUN YOU GAO SIYU WANG YONGYUAN CHU HAIRUN GUO Key Laboratory of Specialty Fiber Optics and Optical Access Networks Joint International Research Laboratory of Specialty Fiber Optics and Advanced CommunicationShanghai UniversityShanghai 200444China

Soliton microcombs have shown great potential in a variety of applications ranging from chip-scale frequency metrology to optical communications and photonic data center,in which light couplings among cavity transverse modes,termed as intermode interactions,are long-existing and usually give rise to localized impacts on the soliton *** particular interest are whispering gallery mode-based crystalline resonators,which with dense mode families,potentially feature interactions of all *** effects of narrowband interactions such as spectral power spikes have been well recognized in crystalline resonators,those of broadband interactions remain ***,we demonstrate microcombs with broadband and dispersive intermode interactions,in homedeveloped magnesium fluoride microresonators with an intrinsic Q-factor approaching 10 *** addition to conventional soliton comb generation in the single-mode pumping scheme,comb states with broadband spectral tailoring effect have been observed,via an intermode pumping ***,footprints of both constructive and destructive interference on the comb spectrum have been observed,which as confirmed by simulations,are connected to the dispersive effects of the coupled mode *** results would not only contribute to the understanding of dissipative soliton dynamics in multi-mode or coupled resonator systems,but also extend the access to stable soliton combs in crystalline microresonators where mode control and dispersion engineering are usually challenging.

关键词： pumping resonator mode

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中国土地沙漠化经济损失评估

中国沙漠 2006年第1期26卷 40-46页

作者：刘拓北京林业大学经济管理学院

以1999年国家荒漠化监测数据为基准,采用灾害经济评价方法,20世纪末我国沙漠化造成的直接经济损失每年约为1 281.41亿元。其中,土地沙漠化造成资源损失955.71亿元,占总损失的74.58%;对农牧业生产造成损失266.99亿元,占总损失的20.84%。... 详细信息

以1999年国家荒漠化监测数据为基准,采用灾害经济评价方法,20世纪末我国沙漠化造成的直接经济损失每年约为1 281.41亿元。其中,土地沙漠化造成资源损失955.71亿元,占总损失的74.58%;对农牧业生产造成损失266.99亿元,占总损失的20.84%。研究表明,全国每年因土地沙漠化所造成的经济损失占当年全国GDP的1.41%,占我国土地沙漠化土地主要分布省区(内蒙古、甘肃、新疆、青海、宁夏、陕西)当年GDP的23.64%,相当于上述五省区1999年财政收入的3.

关键词：土地沙漠化沙漠化灾害评价最终效果原则

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伊朗旧石器考古简史及早期文化的发现与研究

人类学学报 2017年第1期36卷 49-61页

作者：刘拓北京大学考古文博学院北京100871

伊朗作为亚洲大陆腹地沟通东西方的大国,对探究旧石器时代早期东亚和西方石器工业面貌的差异,是重要的地理节点。然而伊朗旧石器的材料相对匮乏,外人知之甚少。为方便理解,本文首先介绍了伊朗的自然与政区地理概况,梳理了伊朗一百多年... 详细信息

伊朗作为亚洲大陆腹地沟通东西方的大国,对探究旧石器时代早期东亚和西方石器工业面貌的差异,是重要的地理节点。然而伊朗旧石器的材料相对匮乏,外人知之甚少。为方便理解,本文首先介绍了伊朗的自然与政区地理概况,梳理了伊朗一百多年旧石器考察、发掘和研究的时间脉络,在此基础上,对其旧石器时代早期文化的发现与研究现状予以整理。伊朗旧石器的研究程度目前尚低,不宜过早做出结论;从现有证据看,伊朗西部受一定程度的阿舍利传统影响,而东部几乎不见;最后从传播路径的角度,推测了伊朗及周边地区在旧石器时代早期可能的文化图景。

关键词：伊朗旧石器时代早期研究史综述阿舍利