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Dispersion of Ultrafast Optical Kerr Effect in No-aggregation Phthalocyanine Molecules

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Chinese Physics Letters 1997年第2期14卷 96-99页

作者： GONG Qi-huang t.Isoshima M.Q.tian t.Wada h.Sasabe Department of Physics Mesoscopic Physics LaboratoryPeking UniversityBeijing 100871 Frontier Research Program Institute of Physical and Chemical Research(RIKEN)WakoSaitama 351-01Japan

We report dispersion property for femtosecond optical Kerr effect in the solutions of no-aggregation 16(trifluoro ethoxy1)vanadyl phthalocyanine in the wavelength range of 850-770 *** optical Kerr effect spectrum show... 详细信息

关键词： optical Dispersion effect

Synthesis of crystalline perovskite-structured SrtiO_3 nanoparticles using an alkali hydrothermal process

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International Journal of Minerals,Metallurgy and Materials 2016年第1期23卷 109-115页

作者： U.K.N.Din t.h.t.Aziz M.M.Salleh A.A.Umar Institute of Microengineering and Nanoelectronics (IMEN) Universiti Kebangsaan Malaysia

We report an experimental route for synthesizing perovskite-structured strontium titanate （SrtiO3） nanocubes using an alkali hydrothermal process at low temperatures without further heating. Furthermore, we studied the influence of heating time （at 180℃） on the crystallinity, morphology, and perovskite phase formation of SrtiO3. the SrtiO3 powder, which is formed via nanocube agglomeration, transforms into cubic particles with a particle size of 120--150 nm after 6 h of hydrothermal sintering. the crystallinity and percentage of the perovskite phase in the product increased with heating time. the cubic particles contained 31.24at% anatase tiO2 that originated fi＇om the precursor. By varying the weight ratio of anatase tiO2 used to react with the strontium salt precursor, we reduced the anatase-tiO2 content to 18.8at%. however, the average particle size increased when the anatase-tiO2 content decreased.

关键词： strontium titanate nanoparticles anatase hydrothermal synthesis

Peripheral Nonlinear time Spectrum Features Algorithm for Large Vocabulary Mandarin Automatic Speech Recognition

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tsinghua Science and technology 2005年第2期10卷 174-182页

作者： Fadhil h.t.Al-dulaimy 王作英 Department of Electronic Engineering Tsinghua University Beijing 100084 China

this work describes an improved feature extractor algorithm to extract the peripheral features of point x(ti,fj) using a nonlinear algorithm to compute the nonlinear time spectrum (NL-tS) pattern. the algo- rithm observes n×n neighborhoods of the point in all directions, and then incorporates the peripheral fea- tures using the Mel frequency cepstrum components (MFCCs)-based feature extractor of the tsinghua elec- tronic engineering speech processing (thEESP) for Mandarin automatic speech recognition (MASR) sys- tem as replacements of the dynamic features with different feature combinations. In this algorithm, the or- thogonal bases are extracted directly from the speech data using discrite cosime transformation (DCt) with 3×3 blocks on an NL-tS pattern as the peripheral features. the new primal bases are then selected and simplified in the form of the ?dp- operator in the time direction and the ?dp- operator in the frequency di- t f rection. the algorithm has 23.29% improvements of the relative error rate in comparison with the standard MFCC feature-set and the dynamic features in tests using thEESP with the duration distribution-based hid- den Markov model (DDBhMM) based on MASR system.

关键词： large vocabulary speech recognition Mandarin automatic speech recognition (MASR) dura- tion distribution-based hidden Markov model (DDBhMM) feature identification

A new computational approach for modeling diffusion tractography in the brain

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Neural Regeneration Research 2017年第1期12卷 23-26页

作者： harsha t.Garimella Reuben h.Kraft Department of Mechanical and Nuclear Engineering Department of Biomedical EngineeringThe Pennsylvania State UniversityUniversity ParkPAUSA

Computational models provide additional tools for studying the brain,however,many techniques are currently disconnected from each *** is a need for new computational approaches that span the range of physics operating in the *** this review paper,we offer some new perspectives on how the embedded element method can fill this gap and has the potential to connect a myriad of modeling *** embedded element method is a mesh superposition technique used within finite element *** method allows for the incorporation of axonal fiber tracts to be explicitly ***,we explore the use of the approach beyond its original goal of predicting axonal strain in brain *** explore the potential application of the embedded element method in areas of electrophysiology,neurodegeneration,neuropharmacology and *** conclude that this method has the potential to provide us with an integrated computational framework that can assist in developing improved diagnostic tools and regeneration technologies.

关键词： embedded elements finite element analysis computational biomechanics explicit axonal fiber tracts neural regeneration diffusion tractography

Magnetic field induction and magnetic force distribution profiles in plasma focus discharge device

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Plasma Science and technology 2021年第7期23卷 110-120页

作者： A A LAShIN t M ALLAM h A EL-SAYED Kamal M AhMED S A WARD h M SOLIMANand M A ABOUELAttA Plasma and Nuclear Fusion Department Nuclear Research CentreEgyptian Atomic Energy AuthorityInshas 13759Egypt Faculty of Engineering Delta University for Science and TechnologyGamasa 11152Egypt Electrical Engineering Department Faculty of Engineering at ShoubraBenha UniversityCairo 11629Egypt

We report a simple-to-perform technique to investigate the distribution of the azimuthal magnetic field induction,Bθ,and the induced magnetic force acting on the plasma current sheath(PCS)in a plasma focus(PF)*** in situ measurement technique can undoubtedly be beneficial when other fast-imaging techniques are not *** are not *** work was conducted in the low-energy Mather-type EAEA-PF1 device operated in *** axial distribution(Bθ)z along the coaxial electrodes system was measured with a four magnetic-probe set technique at different radial distances(r=2.625×10^(−2) to 4.125×10^(−2) m)within the annular space between the coaxial electrodes during the 1st and 2nd half cycles of the discharge current waveform,where inner electrode of coaxial electrode system has a+ve polarity and−ve polarity,***,radial and total magnetic force distribution profiles were estimated from Bθ*** of PCS shape in terms of its inclination(curvature)angle,θ,along the axial rundown phase and the correlation between the magnetic forces per unit volume acting on the PCS,the inclination angleθof the PCS,and the formation of a powerful PF action during the 1st and 2nd half cycles is carried *** of inclination angle,θ,on total magnetic force per unit volume acting on PCS axial motion was studied,separately,during the 1st and 2nd half cycles.

关键词： plasma focus azimuthal magnetic field magnetic force inclination angle plasma current sheath

Skew Pairs of Idempotents in transformation Semigroups

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Acta Mathematica Sinica,English Series 2006年第6期22卷 1705-1714页

作者： t.S.BLYth M.h.ALMEIDA SANtOS Mathematical Institute University of St Andrews Departamentode Matemática F.C.T.Universidade Nova de Lisboa

An ordered pair （e, f） of idempotents of a regular semigroup is called a skew pair if ef is not idempotent whereas fe is idempotent. We have shown previously that there are four distinct types of skew pairs of idemp... 详细信息

关键词： full transformation semigroups idempotents skew pairs

Influence of Gaps Between Multiple Floating Bodies on Wave Forces

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China Ocean Engineering 2000年第4期15卷 407-422页

作者：缪国平 h. Ishida t. Saitoh Professor Department of Civil Engineering Kanazawa University Associate Professor Department of Civil Engineering Kanazawa University

the present study aims to give general hints about hydrodynamic interactions for water wave diffraction on a super large floating structure composed of a large number of box-shaped modules with many small gaps in between. And meanwhile, it also aims to seek for an effective way to take the gap influence into consideration without numerical difficulties existing in conventional methods. An asymptotic matching technique is exploited by virtue of the smallness of gaps. Formal potential solutions are established for the near field around the gap ends and the far field away from gap ends, respectively, and the unknowns in those solutions are uniquely determined by asymptotic matching. the eigen-function expansion method is used for the outer far field and a series of pulsating sources at each gap end is introduced to simulate the gap influence. Strong hydrodynamic interaction is observed and a new resonant phenomenon, the mechanism of which differs absolutely from any known ones, is revealed in the present study. Sharp peak responses for both vertical and horizontal wave-exciting forces on each block are found around some special resonance frequencies, which depend on the draft of the structure and the gap width. the present results are of practical significance to the design of links (connectors) of modules for super large floating structures. And the importance is also closely related to the hydro-elasticity analysis for super large floating structures, in which local loads may be as important as the integrated loads.

关键词： super large floating structure wave interaction resonance gap influence

Mechanical Property Prediction of Commercially Pure titanium Welds with Artificial Neural Network

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Journal of Materials Science & technology 2005年第3期21卷 403-407页

作者： YanhongWEI K.K.D.h.Bhadeshia t.Sourmail StateKeyLaboratoryofAdvancedWeldingProductiontechnology HarbinInstituteofTechnologyHarbin150001China DepartmentofMaterialsScienceandMetallurgy UniversityofCambridgeCambridgeCB23QZUK

Factors that affect weld mechanical properties of commercially pure titanium have been investigated using artificial neural networks. Input data were obtained from mechanical testing of single-pass, autogenous welds, and neural network models were used to predict the ultimate tensile strength, yield strength, elongation, reduction of area, Vickers hardness and Rockwell B hardness. the results show that both oxygen and nitrogen have the most significant effects on the strength while hydrogen has the least effect over the range investigated. Predictions of the mechanical properties are shown and agree well with those obtained using the 'oxygen equivalent' (OE) equations.

关键词： Commercially pure titanium Artificial neural networks Mechanical properties Weld

Frequency equations of nonlocal elastic micro/nanobeams with the consideration of the surface effects

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Applied Mathematics and Mechanics(English Edition) 2018年第8期39卷 1089-1102页

作者： h.S.ZhAO Y.ZhANG S.t.LIE School of Civil and Environmental Engineering Nanyang Technological University

A nonlocal elastic micro/nanobeam is theoretically modeled with the consideration of the surface elasticity, the residual surface stress, and the rotatory inertia,in which the nonlocal and surface effects are considered. three types of boundary conditions, i.e., hinged-hinged, clamped-clamped, and clamped-hinged ends, are examined. For a hinged-hinged beam, an exact and explicit natural frequency equation is derived based on the established mathematical model. the Fredholm integral equation is adopted to deduce the approximate fundamental frequency equations for the clamped-clamped and clamped-hinged beams. In sum, the explicit frequency equations for the micro/nanobeam under three types of boundary conditions are proposed to reveal the dependence of the natural frequency on the effects of the nonlocal elasticity, the surface elasticity, the residual surface stress, and the rotatory inertia, providing a more convenient means in comparison with numerical computations.

关键词： Fredholm integral equation micro/nanobeam natural frequency nonlocal elasticity surface effect