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Petrology, geochemistry, radioactivity, and M–W type rare earth element tetrads of El Sela altered granites, south eastern desert,Egypt

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Acta Geochimica 2019年第1期38卷 95-119页

作者： A.M.El Mezayen M.A.Heikal M.G.El-Feky H.A.Shahin I.K.Abu Zeid S.R.Lasheen Geology Department Faculty of Science Al Azhar University Nuclear Material Authority

The southern part of the Eastern Desert of Egypt—about 30 km southwest of Abu-Ramad city—is mainly covered by ophiolitic rocks(Sul Hamed), island arc assemblage, younger granites(muscovite granites of Qash Amer and two mica granites of El Sela), and various acidic and basic dikes. Field, petrological, and geochemical studies indicate that the El Sela shear zone has been subject to hydrothermal and supergene alteration such as kaolinization, albitization, sericitization, and hematitization. It is invaded by quartz ENE–WSW veins associated with hydrothermal alteration accompanied by radioactive mineralization. The investigated younger granitic rocks had very low contents of compatible elements, such as Cr, Ni,and Co; and high contents of incompatible elements, such as Zr, and large ion lithophiles, such as Sr, especially in the El Sela shear zone. Major oxide and trace element analyses revealed calc-alkaline affinity and peraluminous character.These highly differentiated granitic rocks' lower Zr/Hf and higher Y/Ho than the normal ratio are consistent with hydrothermal alteration. Most samples had rare earth element(REE)-patterns with an M-type tetrad effect in the first and fourth segments and a W-type tetrad in the third segment. The average ∑REE in the studied granites was lower than the world granite average; the ratio of light to heavy REEs greater. The main radioactive, uranium-bearing, and uraniferous Fe and Mn minerals are uranothorite,autunite, uranophane and autunite as compounds, kasolite,columbite, xenotime, uranophane-bearing zircon and jarosite, silver-bearing pyrite, hematite, and autunite-bearing pyrolusite.

关键词： Geochemistry REE-tetrad effect Radioactive minerals Radiometric measurements Qash Amer El Sela

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Recursive Approximation of Complex Behaviours With IoT-Data Imperfections

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IEEE/CAA Journal of Automatica Sinica 2020年第3期7卷 656-667页

作者： Korkut Bekiroglu Seshadhri Srinivasan Ethan Png Rong Su Constantino Lagoa College of Engineering SUNY Polytechnic InstituteUtica 13503NYUSA Berkeley Education Alliance for Research in Singapore(BEARS) Singapore 138602Singapore School of Electrical and Electronic Engineering Nanyang Technological UniversitySingapore 639798Singapore IEEE Electrical Engineering Department of Pennsylvania State University ParkPA 16802 USA

This paper presents an approach to recursively estimate the simplest linear model that approximates the time-varying local behaviors from imperfect(noisy and incomplete) measurements in the internet of things(IoT) based distributed decision-making problems. We first show that the problem of finding the lowest order model for a multi-input single-output system is a cardinality(l0) optimization problem, known to be NP-hard.To solve the problem a simpler approach is proposed which uses the recently developed atomic norm concept and the modified Frank-Wolfe(mFW) algorithm is introduced. Further, the paper computes the minimum data-rate required for computing the models with imperfect measurements. The proposed approach is illustrated on a building heating, ventilation, and air-conditioning(HVAC) control system that aims at optimizing energy consumption in commercial buildings using IoT devices in a distributed manner. The HVAC control application requires recursive thermal dynamical model updates due to frequently changing conditions and non-linear dynamics. We show that the method proposed in this paper can approximate such complex dynamics on single-board computers interfaced to sensors using unreliable communication channels. Real-time experiments on HVAC systems and simulation studies are used to illustrate the proposed method.

关键词： Adaptability distributed decision systems imperfect measurements internet of things(IoT) low order model identification

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A regularization algorithm for estimating the multimodal size distribution of nanoparticles from multiangle dynamic light scattering

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Particuology 2018年第6期16卷 30-39页

作者： Lei Li Kecheng Yang Wei Li Kai Li Long Yu Min Xia School of Optical and Electronic Information Huazhong University of Science and TechnologyWuhan 430074China Wuhan University Scientific Journals Press Wuhan 430072China

The multiangle dynamic light scattering (MDLS)technique provides more robust,reproducible,and accu- rate particle size distributions (PSDs)than single-angle dynamic light scattering.However,in MDLS,the determination of peak locations is difficult but significant,particularly for multimodal distributions.In this paper,a self-adaptive algorithm,the iterative recursion nonnegative Tikhonov-Phillips-Twomey (IRNNT-PT)algorithm,is proposed for the estimation of the PSD from MDLS measurements.This algorithm optimizes the weighting coefficients,distinguishes features of PSDs and chooses the optimal inversion method from two regularization algorithms self-adaptively.Numerical simulations and experimental results for unimodal and multimodal distributions are presented to demonstrate both the validity and noise immunity of the IRNNT-PT algorithm,and demonstrate that the proposed algorithm can be well applied to reconstruct PSDs from MDLS measurements.

关键词： Dynamic light scattering Particle size distribution Inverse scattering Mie theory Scattering measurements

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Effect of Deep Sea Pressures on the Corrosion Behavior of X65 Steel in the Artificial Seawater

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Acta Metallurgica Sinica(English Letters) 2019年第8期32卷 972-980页

作者： Qiu-Shi Li Shun-Zhong Luo Xu-Teng Xing Jing Yuan Xin Liu Ji-Hui Wang Wen-Bin Hu Tianjin Key Laboratory of Composite and Functional Materials School of Materials Science and EngineeringTianjin UniversityTianjin 300072China College of Physics Electronic Information Engineering Qinghai University for NationalitiesXining 810007China

The corrosion behaviors of X65 steel in the artificial seawater at different hydrostatic pressures are investigated by potentiodynamic polarization measurements, electrochemical impedance spectroscopy measurements and weight loss measurements.The corroded morphologies and the corrosion products are also investigated by scanning electron microscopy, X-ray diffraction analysis and Raman analysis.The results show that the corrosion current increases as the hydrostatic pressure increases.The charge transfer resistance decreases as the hydrostatic pressure increases.The corrosion products are mainly composed of γ-FeOOH and Fe3O4 at the atmospheric pressure, while the main components are γ-FeOOH, Fe3O4, and γ-Fe2O3 at the high pressure.The hydrostatic pressure accelerates the corrosion of X65 steel due to its effect on the chemical and physical properties of corrosion products, including the promoted reduction of γ-FeOOH and the wider and deeper cracks on the corrosion products layer.

关键词： X65 steel Deep sea pressures Electrochemical measurements Corrosion

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Boundary-layer transition of advanced fighter wings at high-speed cruise conditions

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Chinese Journal of Aeronautics 2019年第4期32卷 799-814页

作者： Yiming DU Zhenghong GAO Chao WANG Qianhuan HUANG School of Aeronautics Northwestern Polytechnical University

The achievement of laminar flow in the boundary layer at high-speed cruise conditions may further, in addition to shock-wave control, reduce the drag and extend the range of military fighter aircraft. To this end, a further investigation on transitional boundary-layer flow of fighter wings is needed due to different configurations from the wings used on conventional transport aircraft. In this paper, wind tunnel experiments and numerical simulations were conducted on three-dimensional transition of thin diamond-shaped wings used on advanced fighter aircraft at tran/supersonic design points. A newly proposed correlation of crossflow transition which includes the effect of surface roughness was introduced into the c-Rehttransition model. Predicted results were in good agreement with flow visualizations. Results showed that the strength of the crossflow component grew rapidly around the leading edge because of the severe flow acceleration, just as the same as wings with a large aspect ratio. However, there seemed no regular pattern of instabilitydominance variation in span-wise for a diamond configuration. The dominance of different instability mechanisms strongly depended on the local pressure distribution. Hereby, the research recommended a ‘‘roof-like" shape of pressure distribution to suppress both crossflow and Tollmien-Schlichting(T-S) instabilities. Besides, a sharp suction peak with a serious pressure rise should be cut off to avoid stronger instabilities. Further discussions also revealed an independence of the unit Reynolds number when transition was triggered by T-S instabilities. Aerodynamic force comparisons indicated that further benefit on drag reduction could be expected by including the three-dimensional transition effect into a wing design process.

关键词： Boundary layer transition Fighter aircraft design Supersonic aircraft wings Transonic wing aerodynamics Wind tunnel measurements

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Robust CCD photoelectric autocollimator for outdoor use

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Chinese Optics Letters 2011年第9期9卷 32-36页

作者：高敏董作人卞正兰叶青方祖捷翟荣辉 Shanghai Key Laboratory of All Solid-state Laser and Applied Techniques Shanghai Institute of Optics and Fine MechanicsChinese Academy of Sciences Graduate University of Chinese Academy of Sciences

A robust charge-coupled device （CCD） photoelectric autocollimator for outdoor use is designed and demonstrated. The influence of outdoor conditions on the signal-to-noise ratio （SNR） and imaging quality of the measuring system is experimentally analyzed. The pulse width modulation technology is applied to the automatic feedback control of the actively regulated illuminating light source of the measuring system to maximize SNR while avoiding image saturation. A Fourier phase shift method for subpixel estimation is adopted to achieve high-accuracy measurement in the presence of noises. Experimental results indicate that the technologies proposed here largely improve the measuring stability, dynamic range, and accuracy of the CCD photoelectric autocollimator used outdoors.

关键词： Light sources measurements Robust control Signal to noise ratio

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Development of high-coercivity state in melt-spun Fe41Pd41B8Si6P4 ribbons

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Rare Metals 2020年第1期39卷 76-83页

作者： Oksana Aleksandrovna Golovnia Nina Ivanovna Vlasova Aleksandr Gervasievich Popov Vasiliy Semenovich Gaviko Vladimir Vladimirovich Popov Jr. Andrey Vladimirovich Protasov Arti Kashyap M.N.Miheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences EkaterinburgRussia620990 Institute of Natural Sciences and Mathematics Ural Federal UniversityEkaterinburgRussia620002 Israel Institute of Metals Technion R&D FoundationTechnion City3200003HaifaIsrael Indian Institute of Technology Mandi KamandMandiHP175005India

The phase transformation and magnetic hysteresis properties of melt-spun Fe41 Pd41 B8 Si6 P4 ribbons subjected to the annealing at temperatures of 500-550℃were studied after holding for 0.1-60.0 h by transmission electron microscopy(TEM),X-ray diffraction(XRD)and thermomagnetic analysis.The additions of P,B and Si to the FePd alloy allowed us to achieve the coercivity of124 kA·m-1,which is 2.6 times higher than that of the melt-spun ribbons of the binary equiatomic FePd alloy.The high-coercivity Fe41Pd41B8 Si6 P4 alloy is nanocrystalline and is composed of the ordered L10-phase grains approximately 40 nm in size and inclusions of the Fe2(P,B)and Pd2(Si,B)phases.The coercivity kinetics is controlled by the phase transformation which can be divided into three stages:transformation from the bcc structure to nanosized regions of the fee and Fe2 P phases;transformation from the fee to L10 nanosized regions with somewhat different degrees of tetragonality and their ordering;and extensive growth of the weight fraction of L10 phase from the fee nanosized regions.P and B atoms occupy interstitial sites in the iron plane of L10 lattice,thus decreasing its Curie temperature(TC).

关键词： Fe-Pd-P-B-Si Melt spinning L10 Nanostructured materials Phase transformation Magnetic measurements

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Investigation on Measurement of Size and Concentration of Solid Phase Particles in Gas-Solid Two Phase Flow

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Chinese Journal of Electronics 2018年第2期27卷 381-385页

作者： WANG Yueming LYU Xiaoqi LI Wentao YAO Guodong BAI Junyuan BAO An School of Information Engineering Inner Mongolia University of Science and Technology

Gas-solid two phase flow measurements have a wide range of applications in industrial production and scientific research. Based on optical principle and image processing, a measurement method of solid phase particle size and concentration of gas-solid two phase flow was presented, and an experimental system was built. By theoretical analysis and image processing algorithms, solid phase particle sizes and concentrations in gas-solid two phase flow were achieved.

关键词： Gas-solid two phase flow Particle size Concentration measurements

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A three-step system calibration procedure with error compensation for 3D shape measurement

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Chinese Optics Letters 2010年第1期8卷 33-37页

作者：崔海华廖文和程筱胜戴宁袁天然 College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and Astronautics

System calibration, which usually involves complicated and time-consuming procedures, is crucial for any three-dimensional （3D） shape measurement system based on vision. A novel improved method is proposed for accurate calibration of such a measurement system. The system accuracy is improved with considering the nonlinear measurement error created by the difference between the system model and real measurement environment. We use Levenberg-Marquardt optimization algorithm to compensate the error and get a good result. The improved method has a 50% improvement of re-projection accuracy compared with our previous method. The measurement accuracy is maintained well within 1.5% of the overall measurement depth range.

关键词： Birefringence Calibration Error compensation measurements Model structures

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Improved digital processing method used for image motion measurement based on hybrid opto-digital joint transform correlator

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Chinese Optics Letters 2010年第10期8卷 989-992页

作者：易红伟赵惠李英才汶德胜 Xi’an Institute of Optics and Precision Mechanics Chinese Academy of Sciences

Hybrid opto-digital joint transform correlator （HODJTC） is effective for image motion measurement, but it is different from the traditional joint transform correlator because it only has one optical transform and the joint power spectrum is directly input into a digital processing unit to compute the image shift. The local cross-correlation image can be directly obtained by adopting a local Fourier transform operator. After the pixel-level location of cross-correlation peak is initially obtained, the up-sampling technique is introduced to relocate the peak in even higher accuracy. With signal-to-noise ratio ≥ 20 dB, up-sampling factor k ≥ 10 and the maximum image shift ≤ 60 pixels, the root-mean-square error of motion measurement accuracy can be controlled below 0.05 pixels.

关键词： Fourier transforms measurements Optical correlation Processing Signal to noise ratio

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