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Acoustic Nonlinearity Parameters Due to Microstructural Defects

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Acta Mechanica Solida Sinica 2018年第5期31卷 525-534页

作者： Xiang Gao Jianmin qu Department of Mechanical Engineering Tufts University Medford MA 02155 USA

This study presents a general approach to derive the acoustic nonlinearity parameters induced by various types of dislocation configurations including dislocation strings （monopoles）, dislocation dipoles, dislocation pileups and extended dislocations. It is found that expressions of the acoustic nonlinearity parameter induced by such a variety of dislocation con- figurations share a common mathematical form. They are all scaled with （Lch/b）n, where Lch is a characteristic length of the dislocation configuration, b is the magnitude of the Burgers vector, and n is either 3 or 4. Semiquantitative analysis is presented to compare the magnitudes of the acoustic nonlinearity parameters among different types of dislocation configurations.

关键词： Nonlinear ultrasound Nondestructive evaluation Acoustic nonlinearity parameter Microstructural defects Dislocations

Steady Compressible Euler Equations of Concentration Layers for Hypersonic-limit Flows Passing Three-dimensional Bodies and Generalized Newton-Busemann Pressure Law

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Chinese Annals of Mathematics,Series B 2023年第4期44卷 561-576页

作者： Aifang qu Hairong YUAN Department of Mathematics Shanghai Normal UniversityShanghai 200234China School of Mathematical Sciences and Shanghai Key Laboratory of Pure Mathematics and Mathematical Practice East China Normal UniversityShanghai 200241China

For stationary hypersonic-limit Euler flows passing a solid body in three-dimensional space,the shock-front coincides with the upwind surface of the body,hence there is an infinite-thin layer of concentrated mass,in which all particles hitting the body move along its upwind *** proposing a concept of Radon measure solutions of boundary value problems of the multi-dimensional compressible Euler equations,which incorporates the large-scale of three-dimensional distributions of upcoming hypersonic flows and the small-scale of particles moving on two-dimensional surfaces,the authors derive the compressible Euler equations for flows in concentration layers,which is a stationary pressureless compressible Euler system with source terms and independent variables on curved *** a by-product,they obtain a formula for pressure distribution on surfaces of general obstacles in hypersonic flows,which is a generalization of the classical Newton-Busemann law for drag/lift in hypersonic aerodynamics.

关键词： Compressible Euler equations Hypersonic fow Concentration layer Ramp Cone Radon measure solution Newton-Busemann law

DESIGN AND ANALYSIS OF HIGH-THROUGHPUT SCREENING EXPERIMENTS

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Journal of Systems Science & Complexity 2011年第4期24卷 711-724页

作者： Xianggui qu Department of Mathematics and Statistics Oakland University Rochester MI 48309 USA.

Saturated row-column designs are studied to eliminate positional effects in primary high- throughput screening experiments. Compared to designs currently used in practice, all compounds in the designs considered are comparable within each microplate in spite of the existence of row and column effects. The designs considered in this paper also have the maximum number of compounds arranged in each microplate. Two statistical methods are used to choose leading compounds in the designs considered. These two methods take full advantages of effect sparsity in primary screening. Simulation studies are carried out to compare the two statistical methods with two ad hoc methods in selecting active compounds. A method that maintains balanced false positives and false negatives is recommended.

关键词： Bscore high-throughput screening row-column design saturated design Zscore.

Distribution Patterns of Calcite Cement in the Turbidite Sandstones of the Shahejie Formation in the Dongying Depression,Eastern China

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Acta Geologica Sinica(English Edition) 2022年第3期96卷 1041-1056页

作者： ZHANG Yongwang qu Zhengyang State Key Laboratory of Petroleum Resources and Prospecting Beijing 102249China College of Geosciences China University of Petroleum-BeijingBeijing 102249China No.4 Oil Production Plant PetroChina Changqing Oilfield CompanyYinchuan 718500China

Calcite cements are volumetrically dominant among the most diagenetic constituents in turbidite sandstones of the Paleogene Shahejie Formation in the Dongying *** results show carbonate cements mainly occur in three phases:Calcite I(pre-compaction),Calcite II(post-compaction)and ankerite in the turbidite *** isotopic composition of Calcite I and Calcite II range from−4.3‰to 4.4‰,−3.5‰to 4.3‰PDB,respectively,suggesting that the calcite cements are mainly derived from the interbedded *** early calcite cement precipitated from the mixing of lacustrine and meteoric waters at 38-69℃.The late-phase calcite precipitated from pore waters modified by water-rock interactions at 64-126℃.Two distribution patterns of calcite cements can be identified,depending on their position within the *** peripheral cementation of the sandstones is near the sand-shale *** development of cement is controlled by sandstone thickness and the properties of the interbedded *** scattered cementation,the distribution of the calcite cement is not controlled by the sand-shale *** cement was preferentially distributed in coarse-grained sandstones,indicating that sandstones with high original permeability are the preferred pathway for the migration of early diagenetic fluids.

关键词： turbidite sandstone calcite cement distribution patterns Dongying Depression

Advances in tissue state recognition in spinal surgery:a review

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Frontiers of Medicine 2021年第4期15卷 575-584页

作者： Hao qu Yu Zhao Department of Orthopaedics Peking Union Medical College HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100730China

Spinal disease is an important cause of cervical discomfort,low back pain,radiating pain in the limbs,and neurogenic intermittent claudication,and its incidence is increasing *** the etiological viewpoint,these symptoms are directly caused by the compression of the spinal cord,nerve roots,and blood vessels and are most effectively treated with *** surgeries are primarily performed using two different techniques:spinal canal decompression and internal *** the past,tactile sensation was the primary method used by surgeons to understand the state of the tissue within the operating ***,this method has several disadvantages because of its ***,it has become the focus of spinal surgery research so as to strengthen the objectivity of tissue state recognition,improve the accuracy of safe area location,and avoid surgical injury to *** from traditional imaging methods,surgical sensing techniques based on force,bioelectrical impedance,and other methods have been gradually developed and tested in the clinical *** article reviews the progress of different tissue state recognition methods in spinal surgery and summarizes their advantages and disadvantages.

关键词： spinal surgery tissue state recognition image force sensing bioelectrical impedance

Impedance spectroscopy for quantum dot light-emitting diodes

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Journal of Semiconductors 2023年第9期44卷 26-38页

作者： Xiangwei qu Xiaowei Sun Institute of Nanoscience and Applications and Department of Electrical and Electronic EngineeringSouthern University of Science and TechnologyShenzhen 518055China Key Laboratory of Energy Conversion and Storage Technologies(Southern University of Science and Technology) Ministry of Educationand Shenzhen Key Laboratory for Advanced Quantum Dot Displays and LightingSouthern University of Science and TechnologyShenzhen 518055China

Impedance spectroscopy has been increasingly employed in quantum dot light-emitting diodes(QLEDs)to investigate the charge dynamics and device *** this review,we introduce the mathematical basics of impedance spectroscopy that applied to *** particular,we focus on the Nyquist plot,Mott-Schottky analysis,capacitance-frequency and capacitance-voltage characteristics,and the d C/d V measurement of the *** impedance measurements can provide critical information on electrical parameters such as equivalent circuit models,characteristic time constants,charge injection and recombination points,and trap distribution of the ***,this paper will also discuss the disadvantages and limitations of these ***,this review provides a deeper understanding of the device physics of QLEDs through the application of impedance spectroscopy,offering valuable insights into the analysis of performance loss and degradation mechanisms of QLEDs.

关键词： quantum dot light-emitting diode impedance spectroscopy equivalent circuit model charge dynamics

Recent advancement of chemical imaging in pharmaceutical quality control:From final product testing to industrial utilization

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Journal of Innovative Optical Health Sciences 2020年第1期3卷 19-34页

作者： Luming Liu Haibin qu College of Pharmaceutical Sciences Zhejiang University HangzhouZhejiang 310058P.R.China

Chemical imaging(CI)possesses a strong ability of pharmaceutical *** great strength relies on the integration of traditional spectroscopy(one dimension)and imaging technique(two dimensions)to generate three-dimensional data *** pre-processing or processing methods are proposed to analyze vast data matrixes and thereby realizing different research *** this review paper,various pharmaceutical applications of quality control over the past few years are summed up in two groups of final product test and industrial *** scope of"quality control"here includes traditional analytical use,process understanding and manufactural ***,two major challenges about undesirable sample geometry and lengthy acquisition time are discussed for prospective commercial or industrial application.

关键词： Hyperspectral imaging pharmaceutical application multivariate data analysis quality control

Invariant hypersurface flows in centro-affine geometry

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Science China Mathematics 2021年第8期64卷 1715-1734页

作者： Yun Yang Changzheng qu Department of Mathematics Northeastern UniversityShenyang 110819China School of Mathematics and Statistics Ningbo UniversityNingbo 315211China

In this paper,the invariant geometric flows for hypersurfaces in centro-affine geometry are *** first present evolution equations of the centro-affine invariants corresponding to the geometric *** on these fundamental evolution equations,we show that the centro-affine heat flow for hypersurfaces is equivalent to a system of ordinary differential equations,which can be solved ***,the centro-affine invariant normal flows for hypersurfaces are investigated,and two specific flows are provided to illustrate the behaviour of the flows.

关键词： invariant geometric flow centro-affine geometry heat flow normal flow centro-affine invariant

Mesoporous Silica MCM-48 Membrane Synthesized on a Coarse-pore α-Al_2O_3 Ceramic Tube

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Chemical Research in Chinese Universities 2005年第2期21卷 131-133页

作者： LIUChun-yan WANGJin-qu InstituteofAdsorptionandInorganicMembrane DalianUniversityofTechnologyDalian116012P.R.Chinas／／FacultyofChemistryandChemicalEngineeringLiaoningNormalUniversityDalian116029P.R.China InstituteofAdsorptionandInorganicMembrane DalianUniversityofTechnologyDalian116012P.R.Chinas

A mesoporous MCM-48 membrane was synthesized on a coarse-pore α-alumina ceramic tube by hydrothermal treatment by using a cationic surfactant as the structure-directing agent under basic conditions. The products were characterized by small-angle X-ray diffraction, SEM measurements and N_2 adsorption experiments. The X-ray diffraction(XRD) results show that the membrane possesses a periodic mesostructure, which is typical for an MCM-48 material. The results of the SEM measurements indicate that MCM-48 grew in the pores of the support and formed a continuous membrane. The N_2 adsorption and desorption isotherms also show that the membrane is a typical mesoporous material with pore channel size of about 2.74 nm.

关键词： Mesoporous membrane MCM-48 Synthesis Alumina support