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Observation of Near-Inertial Internal Waves on the Continental Slope in the Northwestern South China Sea

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Journal of Ocean University of China 2017年第2期16卷 184-190页

作者： ZHENG Jie TIAN Jiwei liang hui Physical Oceanography Laboratory Ocean University of ChinaQingdao 266100P.R.China

Based on nearly 3 months of moored acoustic Doppler current profiler records on the continental slope in the northwestern South China Sea(SCS) in 2006,this study examines temporal and vertical characteristics of near-inertial internal waves(NIW).Rotary frequency spectrum indicates that motions in the near-inertial frequency are strongly polarized,with clockwise(CW) energy exceeding counterclockwise(CCW) by about a factor of *** analysis exhibits an energy peak exceeding the 95% confidence level at the frequency of local inertial during the passage of typhoon Xangsane(24 September to 4 October).This elevated near-inertial kinetic energy(NIKE) event possesses about a 4 days delay correlation with the time integral of energy flux induced by typhoon,indicating an energy source of *** analysis shows that the upward phase velocity of this event is 3.8 m h^(-1)approximately,corresponding to a vertical wavelength of about 125 m if not taking the redshift of local inertial frequency into *** vertical wavenumber spectrum exhibits the dominance of clockwise-with-depth energy,indicating downward energy propagation and implying a surface energy *** modes suggest that mode 1 plays a dominant role at the growth stage of NIW,whereas major contribution is from higher modes during the penetration of NIKE into the ocean interior.

关键词： South China Sea near-inertial internal waves mooring

The Spectral Gap for Quasi-birth and Death Processes

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Acta Mathematica Sinica,English Series 2012年第5期28卷 1075-1090页

作者： Yong Hua MAO liang hui XIA School of Mathematical Sciences LMCSMinistry of EducationBeijing Normal University Department of Mathematics Ji'nan University

For a reversible quasi-birth and death process, we generalize and refine the decomposition method, by constructing a birth-death process and a sequence of restriction processes. The spectral gap for the quasi-birth and death process is estimated in terms of the spectral gaps for these processes, and in some special cases, the estimation is sharp. With the aid of the symmetrization procedure, the result is also applied to two queueing models： M/M/1 in random environment and MIMIc with synchronous vacation.

关键词： Quasi-birth and death process spectral gap birth-death process M/M/1 in random environment MIMIc with synchronous vacation

Symplectic Approach on the Wave Propagation Problem for Periodic Structures with Uncertainty

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Acta Mechanica Solida Sinica 2019年第3期32卷 287-297页

作者： Yan Zhao hui liang Youwei Zhang Jiahao Lin State Key Laboratory of Structural Analysis for Industrial Equipment Department of Engineering Mechanics International Center for Computational Mechanics Dalian University of Technology Dalian 116023 China

An effective method is proposed in this paper for the symplectic eigenvalue problem of a periodic structure with uniform stochastic properties. Since structural parameters are uncertain, the symplectic transfer matrix of a typical substructure, which is described in the state space, also has sto chastic proper ties. An effec tive spec tral st ochastic finite elemen t method is adopted to ensure the symplectic orthogonality of the random symplectic matrix on the premise of certain precision. By means of the Rayleigh quotient method, the symplectic eigenvalue problem of random symplectic matrix is investigated. On the basis of this, the mean value and the standard deviation of the random eigenvalues are fully discussed. The comparison between the numerical results derived from the proposed method and the Monte-Carlo simulation indicates that the proposed method has high precision. This research provides a useful guidance for the dynamic analysis of periodic structures with stochastic properties.

关键词： Periodic structures Spectrum method Random symplectic matrix Symplectic eigenvalue

Research on Auto-detection for Remainder Particles of Aerospace Relay Based on Wavelet Analysis

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Chinese Journal of Aeronautics 2007年第1期20卷 75-80页

作者： GAO Hong-liang ZHANG hui WANG Shu-juan Department of Electrical Engineering Harbin Institute of Technology Harbin 150001 China

Aerospace relay is one kind of electronic components which is used widely in national defense system and aerospace system. The existence of remainder particles induces the reliability declining, which has become a severe problem in the development of aerospace relay. Traditional particle impact noise detection （PIND） method for remainder detection is ineffective for small particles, due to its low precision and involvement of subjective factors. An auto-detection method for PIND output signals is proposed in this paper, which is based on direct wavelet de-noising （DWD）, cross-correlation analysis （CCA） and homo-filtering （HF）, the method enhances the affectivity of PIND test about the small particles. In the end, some practical PIND output signals are analysed, and the validity of this new method is proved.

关键词： aerospace relay remainder particles PIND wavelet analysis

Colorimetric characterization of imaging device by total color difference minimization

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第6期7卷 1041-1045页

作者： MOU Tong-sheng SHEN hui-liang State Key Laboratory of Modern Optical Instrumentation Zhejiang University Hangzhou 310027 China Department of lnformation and Electronic Engineering Zhejiang University Hangzhou 310027 China

Colorimetric characterization is to transform the device-dependent responses to device-independent colorimetric values, and is usually conducted in CIEXYZ space. However, the optimal solution in CIEXYZ space does not mean the mini-mization of perceptual error. A novel method for colorimetric characterization of imaging device based on the minimization of total color difference is proposed. The method builds the transform between RGB space and CIELAB space directly using the downhill simplex algorithm. Experimental results showed that the proposed method performs better than traditional least-square (LS) and total-least-square (TLS) methods, especially for colors with low luminance values.

关键词： Colorimetric characterization Color difference Imaging device

Rheological properties and microscopic mechanism of waste cooking oil activated waste crumb rubber modified asphalt

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Journal of Road Engineering 2022年第4期2卷 357-368页

作者： Xinjun Feng hui liang Zijian Dai School of Traffic&Transportation Engineering Changsha University of Science&TechnologyChangsha 410114China

In this paper,the surface activated crumb rubber with waste cooking oil(WCO)was studied to improve the performance of crumb rubber modified *** activated waste crumb rubber modified asphalt(OCRMA)with different amount of crumb rubber was prepared to study the microscopic appearance of OCRMA by scanning electron microscope and fluorescence microscope and analyze the surface *** rheological properties and microscopic mechanism of OCRMA were characterized by dynamic shear rheological test,multiple stress creep recovery(MSCR)test,BBR test and infrared *** results show that the dissolution degree of waste crumb rubber is improved after WCO activation,and the compatibility with asphalt components is enhanced,and the stable cross-linking structure is formed,which improves the asphalt *** several new absorption peaks,which were obvious,were all caused by the composition of WCO,that is,there was no significant chemical change during the interaction between the activated crumb rubber and base *** with the common waste crumb rubber modified asphalt(CRMA),activation with WCO can significantly reduce the viscosity of CRMA,decrease the difference of segregation softening point by 27%,and enhance the low temperature performance by 30%.The aging degree is greatly reduced,and the anti-aging performance of OCRMA is increased by about 20%with the same *** high temperature performance,though higher than that of base asphalt,decreases to some *** comprehensive analysis,the optimal dosage of crumb rubber for OCRMA is 30%.

关键词： Waste crumb rubber Waste cooking oil Surface activated crumb rubber Rheological properties Microcosmic mechanism

High-frequency dielectric properties of BSTO ceramic prepared with hydrothermal synthesized SrTiO_3 and BaTiO_3 powders

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Particuology 2009年第5期7卷 414-418页

作者： Yonghui Xing hui liang Xiaolei Li Liuqi Si Key LaboratoryforAdvanced Ceramics and Machining Technology of Ministry of Education Tianjin University Tianjin 300072 China Shandong Sinocera Functional Material Co. Ltd.. Shandong Dongying 257091 China

BSTO dielectric ceramic was prepared from SrTi03 and BaTi03 powders synthesized by hydrothermal method, as well as from ***.4TiO3 powder synthesized by conventional solid-state reaction. The former can be sintered at a relatively low temperature of 1120 ℃. Characterization by SEM showed that the grain shapes of both ceramics are cubical, though the grain size of the former is much smaller. Dielectric constants measured at 20℃ were shown to vary with frequency in the range from I kHz to 2 MHz and dc bias field, and further that the dielectric loss of the former to be less than 2 × 10^- 3 in the frequency range of 20 kHz to 1 MHz, much smaller than that of the latter sample. For the former, temperature dependence of dielectric constant is much flatter and there exists an extended phase transition diffusion covering a wide temperature range of Curie temperature To. The smaller grain size of the former depresses the dc bias electrical field dependence of dielectric constant. The tunability is 7% under a bias field of 0.6 kV/mm dc.

关键词： Hydrothermal method SrTiO3 BaTiO3 Dielectric properties

NURBS curve blending using extension

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第4期10卷 570-576页

作者： Yong-jin LIU Rong-qi QIU Xiao-hui liang Tsinghua National Lab for Information Science and Technology Tsinghua University Beijing 100084 China State Key Lab of Virtual Reality Technology and Systems Beihang University Beijing 100191 China

Curve and surface blending is an important operation in CAD systems, in which a non-uniform rational B-spline （NURBS） has been used as the de facto standard. In local comer blending, two curves intersecting at that comer are first made disjoint, and then the third blending curve is added-in to smoothly join the two curves with G^1- or G^2-continuity. In this paper we present a study to solve the joint problem based on curve extension. The following nice properties of this extension algorithm are exploited in depth：（1） The parameterization of the original shapes does not change; （2） No additional fragments are created. Various examples are presented to demonstrate that our solution is simple and efficient.

关键词： Curve blending Curve fairing Curve extension Non-uniform rational B-spline (NURBS)

Microstructures and Mechanical Properties of Multi-component AlxCrFe2Ni2Mo0.2 High-Entropy Alloys

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Acta Metallurgica Sinica(English Letters) 2020年第8期33卷 1135-1144页

作者： Qiuxin Nie hui liang Dongxu Qiao Zhaoxin Qi Zhiqiang Cao Key Laboratory of Solidifi cation Control and Digital Preparation Technology(Liaoning Province) School of Materials Science and EngineeringDalian University of TechnologyDalian 116024China Ningbo Institute of Dalian University of Technology Ningbo 315000China

A series of AlxCrFe2 Ni2 Mo0.2 alloy consisting of FCC+BCC phases have been designed,and their as-cast microstructures and mechanical properties were also investigated with x ranging from 0.6 to *** was found that with the addition of Al element,the solidified structures changed from dendrite to columnar crystal then back to dendrite ***,the increased amount of BCC phase resulted in finer and more uniform microstructures of FCC[FeCrNi(Mo)]and BCC(Al-Ni)*** yield strength and hardness of alloys showed a similar increasing trend as the volume fraction of BCC phase *** strain hardening rate and strain hardening exponent were calculated to assess the tensile properties of the *** was shown that A10.6CrFe2 Ni2 Mo0.2 exhibited the most excellent and comprehensive mechanical properties due to its high work hardening ability and stable strain hardening *** product of strength and elongation of Al0.6CrFe2 Ni2 Mo0.2reached up to 38.6 GPa%,which was higher than most of the reported as-cast high-entropy alloys.

关键词： High-entropy alloys Mechanical properties Microstructures Strain hardening