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Singular integral operators on product domains along twisted surfaces

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frontiers of Mathematics in China 2021年第1期16卷 13-28页

作者： Ahmad al-SalMAN Department of Mathematics Sultan Qaboos UniversitySultanateOman Department of MathematicsYarmouk UniversityIrbidJordan

We introduce a class of singular integral operators on product domains along twisted *** prove that the operators are bounded on L^(p) provided that the kernels satisfy weak conditions.

关键词： Singular integral operators on product domains rough kernels L^(p)estimates Hardy Littlewood maximal function truncated maximal singular integrals twisted surfaces block spaces

On the Basis of Taiji Relativity

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Chinese Physics Letters 1996年第5期13卷 321-324页

作者： al Xiao-bai Institute of Nuclear Research Chinese Academy of SciencesShanghai 201800

In this letter author argues that the taiji relativity,which recently developed by Hsu et al.[***.A 196(1994)1],caji not be founded only upon Einstein's first postulate,the principle of *** fact it is still based on t... 详细信息

关键词： letter Einstein relativity

Injection of biosurfactant and chemical surfactant following hot water injection to enhance heavy oil recovery

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Petroleum Science 2016年第1期13卷 100-109页

作者： Yahya al-Wahaibi Hamoud al-Hadrami Saif.al-Bahry Abdulkadir Elshafie ali al-Bemani Sanket Joshi Petroleum and Chemical Engineering Department Sultan Qaboos University Department of Biology College of ScienceSultan Qaboos University

This study investigates the potential of enhancing oil recovery from a Middle East heavy oil field via hot water injection followed by injection of a chemical surfactant and/or a biosurfactant produced by a Bacillus subtilis strain which was isolated from oil-contaminated *** results reveal that the biosurfactant and the chemical surfactant reduced the residual oil saturation after a hot water ***,it was found that the performance of the biosurfactant increased by mixing it with the chemical *** is expected that the structure of the biosurfactant used in this study was changed when mixed with the chemical surfactant as a probable synergetic effect of biosurfactant-chemical surfactants was observed on enhancing oil recovery,when used as a mixture,rather than *** work proved that it is more feasible to inject the biosurfactant as a blend with the chemical surfactant,at the tertiary recovery *** might be attributed to the fact that in the secondary mode,improvement of the macroscopic sweep efficiency is important,whereas in the tertiary recovery mode,the microscopic sweep efficiency matters mainly and it is improved by the biosurfactantchemical surfactant *** as evidenced by this study,the biosurfactant worked better than the chemical surfactant in reducing the residual heavy oil saturation after a hot water flood.

关键词： surfactant Injection attributed macroscopic saturation mixing microscopic contaminated tertiary enhancing

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基于薄膜形状控制的空气静压轴承研究

国防科技参考 1997年第3期18卷 39-42页

作者： f.al-Bender H.Van Brussel 张云洲 Katholieke大学制造工程系机械设计及自动化(PMA) Haverlee(Leuvaen) Belgium Belgium

目前已经提出了一种主动式空气静压轴承,它具有一个可以用压电驱动器来改变形状的规则表面。普遍认为主动补偿方法是最有效的,其原因是小的驱动质量和大的承载力增益及带宽使这种主动式空气静压轴承具有无限大的静态刚度,并具有仅被支... 详细信息

目前已经提出了一种主动式空气静压轴承,它具有一个可以用压电驱动器来改变形状的规则表面。普遍认为主动补偿方法是最有效的,其原因是小的驱动质量和大的承载力增益及带宽使这种主动式空气静压轴承具有无限大的静态刚度,并具有仅被支承机械系统所限制的补偿带宽。微位移测试表明,0.1μm的进给可以相当容易地被高速跟踪。

关键词：空气静压轴承轴承主动式

Temperature-dependent Raman scattering and photoluminescence in YBa2Cu3O7 doped with SiO2 and Zn0.95Mn0.05O nanoparticles:comparative study

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Rare Metals 2019年第8期38卷 754-763页

作者： Munirah A.al Messiere Department of Physics College of ScienceImam Abdulrahman Bin Faisal University

A combined study examining the temperature dependencies of Raman scattering and photoluminescence(PL)of a YBa2 Cu3 O7(YBCO)matrix doped with SiO2(12 nm;0.01 wt%.,0.10 wt%)and Zn0.95Mn0.05O(20 nm;0.02 wt%,0.10 wt%)nanoparticles was presented.X-ray diffraction(XRD)analysis confirms that both YBCO types exhibit aperovskite structure with the orthorhombic Pmmm *** microstructure was examined using environmental scanning electron microscopy(ESEM).Raman scattering and photoluminescence measurements as functions of temperature were conducted in the 77-837 K *** photoluminescence intensity is observed to decrease for the doped YBCO than for the pure YBCO,because of localized *** photoluminescence spectrum is primarily composed of three bands at 1.60,1.88,and 2.40 eV.A clearly pronounced correlation is observed between electronic and structural changes in the doped YBCO,which is due to the temperature,illumination,added oxygen or metal ions,and spectral *** PL integrated intensity as a function of the inverse temperature was simulated using the Arrhenius *** analysis reveals that the energy exchange between the different levels in the pure and doped YBCO was conducted via two vibration modes only,which are strongly linked to the oxygen and copper atoms in the YBCO *** temperature dependencies of the modes at 340 and 500 cm-1 exhibit softening with temperature increase,resulting from microstructure control,which may be due to small concentrations of Si,Zn,and Mn substitutions at the chain Cu(1)and plane Cu(2)sites.

关键词： Matrix YBa2Cu3O7 Nanoparticles Raman scattering Raman modes Photoluminescence spectra

Determination of gamma-ray parameters for polyethylene glycol of different molecular weights

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Nuclear Science and Techniques 2017年第11期28卷 180-187页

作者： Ibrahim f. al-Hamarneh Mohammad W. Marashdeh fahad I. almasoud Ahmad alkaoud Department of Physics Faculty of Science Al-Balqa Applied University Al-Salt 19117 Jordan Department of Physics College of Science Al Imam Mohammad Ibn Saud Islamic University (IMSIU)Riyadh 11623 Saudi Arabia Nuclear Science Research Institute King Abdulaziz City for Science and Technology (KACST) Riyadh 11442 Saudi Arabia National Centre for Nuclear Technology (NCNT) King Abdulaziz City for Science and Technology (KACST)Riyadh 11442 Saudi Arabia

Mass attenuation coefficient(μ_m) for polyethylene glycol(PEG) of different molecular weights was determined by using NaI(Tl) scintillator and Win Xcom mixture rule at gamma energies of 59.5, 302.9, 356.0, 661.7, 1173.2 and 1332.5 keV. The total atomic, molecular and electronic cross sections, half-value layer, effective atomic and electron numbers, mass energy-absorption coefficients and kerma relative to air are calculated. The energy and compositional dependence of μ_m values, and the related radiation absorption parameters, are evaluated and discussed. The experimental results agree well with the theoretical ones, within an uncertainty of 1% in the effective atomic number for all PEG samples at the designated energies.

关键词： Polyethylene glycol Mass attenuation coefficient Effective atomic number Electron density Kerma relative to air

Coupled pile soil interaction analysis in undrained condition

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Journal of Central South University 2013年第5期20卷 1376-1383页

作者： M.Y.fattah f.A.Salman Y.J.al-Shakarchi A.M.Raheem Building and Construction Engineering Department University of Technology Department of Civil Engineering Faculty of EngineeringUniversity of Malaya Department of Civil Engineering College of EngineeringUniversity of Baghdad Department of Civil Engineering College of EngineeringUniversity of Kirkuk

The effective stress method is developed to predict the axial capacity of piles in clay. The effective stress state changes due to the resulting pore pressure change and therefore, the strength and stiffness of the soil will change. In this work, the finite element method is utilized as a tool for the analysis of pile-soil systems in undrained condition. The computer program CRISP was developed to suit the problem requirements. CRISP uses the finite element technique and allows predictions to be made of ground deformation using critical state theories. Eight-node isoparametric element was added to the program in addition to the slip element. A pile loading problem was solved in which the pile-soil system is analyzed in undrained condition. The pile is modelled as elastic-plastic material, while the soil is assumed to follow the modified Cam clay model. During undrained loading condition, the settlement values increase by 22% when slip elements are used. The surface settlement increases by about three times when the load is doubled and the surface settlement at all points increases when using slip elements due to the mode of motion which allows smooth movement of the adjacent soil with respect to the pile. The vertical displacement increases as the distance decreases from the pile and negligible values are obtained beyond 10D (where D is the pile diameter) from the center of the pile and these values are slightly increased when slip elements are used. The vertical effective stress along a section at a distance D from the pile center is approximately the same for all load increments and lower values of effective vertical stress can be obtained when slip elements are used.

关键词： pile finite element coupled analysis undrained condition

Practical fast Computation of Zernike Moments

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Journal of Computer Science & Technology 2002年第2期17卷 181-188页

作者： al-Rawi Mohammed 杨杰 Image Processing and Pattern Recognition Institute Shanghai Jiaotong University Shanghai 200030 P.R. China

The fast computation of Zernike moments from normalized geometric moments has been developed in this paper. The computation is multiplication free and only additions are needed to generate Zernike moments. Geometric moments are generated using Hatamian's filter up to high orders by a very simple and straightforward computation scheme. Other kinds of moments (e.g., Legendre, pseudo Zernike) can be computed using the same algorithm after giving the proper transformations that state their relations to geometric moments. Proper normalizations of geometric moments are necessary so that the method can be used in the efficient computation of Zernike moments. To ensure fair comparisons, recursive algorithms are used to generate Zernike polynomials and other coefficients. The computational complexity model and test programs show that the speed-up factor of the proposed algorithm is superior with respect to other fast and/or direct computations. It perhaps is the first time that Zernike moments can be computed in real time rates, which encourages the use of Zernike momentfeatures in different image retrieval systems that support huge databases such as the XM experimental model stated for the MPEG-7 experimental core. It is concluded that choosing direct computation would be impractical.

关键词： Zernike moment fast algorithm digital filter invariant patternrecognition

Device-free human micro-activity recognition method using Wifi signals

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Geo-Spatial Information Science 2019年第2期22卷 128-137,I0005页

作者： Mohammed A.A.al-qaness School of Computer Science Wuhan UniversityWuhanChina

Human activity tracking plays a vital role in human–computer *** human activity recognition(HAR)methods adopt special devices,such as cameras and sensors,to track both macro-and ***,wireless signals have been exploited to track human motion and activities in indoor environments without additional *** study proposes a device-free Wifi-based micro-activity recognition method that leverages the channel state information(CSI)of wireless *** from existed CSI-based microactivity recognition methods,the proposed method extracts both amplitude and phase information from CSI,thereby providing more information and increasing detection *** proposed method harnesses an effective signal processing technique to reveal the unique patterns of each *** applied a machine learning algorithm to recognize the proposed *** proposed method has been evaluated in both line of sight(LOS)and none line of sight(NLOS)scenarios,and the empirical results demonstrate the effectiveness of the proposed method with several users.

关键词： Human activity recognition channel state information Wifi device-free microactivity recognition machine learning