检索结果-南通市图书馆

High Thermoelectric Figure of Merit of Ag8SnS6 Component Prepared by Electrodeposition Technique

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2015年第12期32卷 126-130页

作者： TAHER Ghrib AMAL Lafy Al-Otaibi MUNIRAH Abdullah Almessiere IBTISSEM Ben Assaker RADHOUANE Chtourou Laboratory of Physical Alloys Science Faculty of Dammam University of Dammam Saudi Arabia laboratoire photovoltaique Centre de Recherches et des Technologies de l'Energie Technopole bozj cedria Bp 95 hammam lif 2050 Tunisie

A new thermoelectric material Ag8SnS6, with ultra-low thermal conductivity in thin film shape, is prepared on indium tin oxide coated g/ass （ITO） substrates using a chemical process via the electrodeposition technique. The structural, thermal and electrical properties are studied and presented in detail, which demonstrate that the material is of semiconductor type, orthorhombic structure, with a band gap in the order of 1.56eV and a free carrier concentration of 1.46 × 10^17 cm-3. The thermal conductivity, thermal diffusivity, thermal conduction mode, Seebeck coefficient and electrical conductivity are determined using the photo-thermal deflection technique combined with the Boltzmann transport theory and Cahill＇s model, showing that the AgsSnS6 material has a low thermal conductivity of 3.8 Wm - 1K- 1, high electrical conductivity of 2.4 × 10^5 Sm- 1, Seebeck coefficient of -180μVK-1 and a power factor of 6.9mWK-2m-1, implying that it is more efficient than those obtained in recently experimental investigations for thermoelectric devices.

关键词： Figure High Thermoelectric Figure of Merit of Ag8SnS6 Component Prepared by Electrodeposition Technique Ag SnS

Substrate Temperature-Dependent Physical Properties of Thermally Evaporated Sn4Sb6S13 Thin Films

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2016年第1期29卷 79-88页

作者： A. Harizi M. Ben Rabeh M. Kanzari laboratoire de photovoltaique et Materiaux Semiconducteurs departement genie industriel ENIT-Universite Tunis E1 Manar BP 37 Le belvedere 1002 Tunis Tunisie Institut Preparatoire aux Etudes d'Ingenieurs de Tunis Universite de Tunisie Montfleury Tunisia

In this work, the homogenous thin films of sulfosalt Sn4Sb6S13 were successfully synthesized by the thermal evaporation technique onto coming 7059 glass substrates heated at various temperatures in the range of 30--200 ℃. The surface morphology and structural characteristics of Sn4Sb6S13 films were analyzed by atomic force microscopy, X-ray diffraction, and energy-dispersive X-ray, respectively. The X-ray diffraction analysis revealed that Sn4Sb6S13 thin films crystallized in monoclinic structure according to a preferential direction （6 11）. An improvement in the structural properties by increasing the substrate temperature was observed. The values of some important parameters such as absorption coefficient （x）, band gap （Eg）, refractive index （n）, extinction coefficient （k）, and dielectric constant （Eg） of thin film were determined. The absorption coefficient was larger than 105 cm-l in the visible range. The electron transition of Sn4Sb6S13 films was direct allowed with the values that decreased （2-1.69 eV） by increasing substrate temperature from 30 to 200 ℃,The dispersion data obeyed the single oscillator relation of the Wemple-DiDomenico model and Cauchy model. The electrical free carrier susceptibility and the carrier concentration of the effective mass ratio were estimated according to the model of Spitzer and Fan.

关键词： Thin film Thermal evaporation technique X-ray diffraction Optical parameters

Numerical studies towards practical large-eddy simulation

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2007年第4期16卷 328-336页

作者： J.Boudet J.Caro L.Shao E.Lév(?)que LMFA laboratoire

Large-eddy simulation developments and validations are presented for an improved simulation of turbulent internal flows. Numerical methods are proposed according to two competing criteria： numerical qualities （precision and spectral characteristics）, and adaptability to complex configurations. First, methods are tested on academic test-cases, in order to abridge with fundamental studies. Consistent results are obtained using adaptable finite volume method, with higher order advection fluxes, implicit grid filtering and ＂low-cost＂ shear-improved Smagorinsky model. This analysis particularly focuses on mean flow, fluctuations, two-point correlations and spectra. Moreover, it is shown that exponential averaging is a promising tool for LES implementation in complex geometry with deterministic unsteadiness. Finally, adaptability of the method is demonstrated by application to a configuration representative of blade-tip clearance flow in a turbomachine.

关键词： LES adaptable methods validation

INTERACTIONS BETWEEN KETONES AND AMINES IN PHOTOINITIATING SYSTEMS USED FOR RADICAL POLYMERIZATION

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 1990年第1期8卷 51-60页

作者：吴世康 FOUASSIER J.P. laboratoire

Time resolved laser spectroscopy and GC/MS were used to investigate the primary processes and the side reactions occurring in benzophenone and chlorothioxanthone/amine systems used as photoinitiators of radical polymerization. The discrepancy observed between the experimental data and the expected behaviour is accounted for by detrimental chemical reaction involving the ketone triplet state, the ketyl radical and the amine-derived radical.

关键词： Photoinitiating systems photopolymerization Benzophenone/Amine system Chlorothioxanthone/Amine system Light absorbing transient (LAT).

Influence of Auxiliary Equation on Wave Functions for Time-Dependent Pauli Equation in Presence of Aharonov-Bohm Effect

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2009年第5期51卷 803-810页

作者： M.Maamache C.Lahoulou Y.Saadi laboratoire

Invariant operator method for discrete or continuous spectrum eigenvalue and unitary transformation approach are employed to study the two-dimensional time-dependent Pauli equation in presence of the Aharonov-Bohm effect （AB） and external scalar potential. For the spin particles the problem with the magnetic field is that it introduces a singularity into wave equation at the origin. A physical motivation is to replace the zero radius flux tube by one of radius R, with the additional condition that the magnetic field be confined to the surface of the tube, and then taking the limit R → 0 at the end of the computations. We point that the invariant operator must contain the step function θ（r - R）. Consequently, the problem becomes more complicated. In order to avoid this dimculty, we replace the radius R by ρ（t）R, where ρ（t） is a positive time-dependent function. Then at the end of calculations we take the limit R →0. The qualitative properties for the invariant operator spectrum are described separately for the different values of the parameter C appearing in the nonlinear auxiliary equation satisfied by p（t）, i.e., C 〉 0, C = 0, and C 〈0. Following the C＇s values the spectrum of quantum states is discrete （C 〉 0） or continuous （C ≤ 0）.

关键词： time-dependent systems invariant theory Aharonov-Bohm effect Pauli equation

PHONONS IN POLYACENIC CHAINS

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2006年第3期24卷 229-236页

作者： O.Rafil M.Tamine B.Bourahla R.Tigrine S.Amoudache A.Khater laboratoire de Physique et Chimie Quantique laboratoire de Physique de l'Etat Condensé

We have theoretically resolved phonon excitations in quasi-two-dimensional organic crystals of polyacenic semiconductor material which may be obtained by the pyrolytic treatment of phenol-formaldehyde resin. A model for studying the dynamical properties using three polyacene chains is proposed with the aim to present the vibrational properties of this structure. It employs the formalism of solid states in two dimensions which admit phonons. A simulation process of the two-dimensional lattice structure shows that elastic waves may explain the existence of vibrational modes in the frequency range 100-400 cm^-1. The presence of acoustic and optical like phonons is discussed in terms of the elastic force constants. A hyperfine resonance structure is obtained. It allows the analysis of the dynamical evolution in thin films of polyacene. It is found that the behavior of the phonon density of states exhibits resonance between modes in the structure.

关键词： Polymers Elastic waves Surface phonons Localized modes

FIBER MIGRATION IN SPINNING

在线全文

学校读者我要写书评

暂无评论

Journal of China Textile University(English Edition) 1991年第4期9卷 18-23页

作者： HUA Vnn Minh ENSITM-laboratoire

Fiber migration in spinning greatly influences the propesties of the resultant *** stud-ying its dynamic behaviour,the author developed a new model of fiber migration and further inves-tigated the effects of factors such as fiber length,fineness and twist level in the *** fromtracer fiber experiments and computer simulation have confirmed the validity of the model as wellas the extent to which the model applies.

关键词： fibre migration spinning amplitude intensity period migration model tracer-fibres

SEPARATION OF SCALES IN ELASTICITY IMAGING:A NUMERICAL STUDY

在线全文

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 2010年第3期28卷 354-370页

作者： Habib Ammari Pierre Garapon Franois Jouve Institut Langevin Laboratoire Ondes et Acoustique laboratoire J.L.Lions Universite Paris Ⅶ laboratoire J.L.Lions Université Paris Ⅶ

In magnetic resonance elastography, one seeks to reconstruct the shear modulus from measurements of the displacement field in the whole body. In this paper, we present an optimization approach which solves the problem by simply minimizing a discrepancy functional. In order to recover a complex anomaly in a homogenous medium, we first observe that the information contained in the wavefield should be decomposed into two parts, a ＂near-field＂ part in the region around the anomaly and a ＂far-field＂ part in the region away from the anomaly. As will be justified both theoretically and numerically, separating these scales provides a local and precise reconstruction.

关键词： Elastography multi-scale imaging anomaly reconstruction.

Quantal studies of sodium 3p ← 3s photoabsorption spectra perturbed by ground lithium atoms

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2019年第6期28卷 146-154页

作者： N Lamoudi F Talbi M T Bouazza M Bouledroua K Alioua Badji Mokhtar University B.P.12 AnnabaAlgeria laboratoire LESIMS laboratoire de Physique des Rayonnements laboratoire LAMA Souk-Ahras University Souk-Ahras 41000Algeria

The pressure broadening in the far wings, where the sodium Na(3 p ← 3 s) resonance line is perturbed by ground lithium Li(2 s) atoms, has been theoretically analyzed. The NaLi potential–energy curves and the transition dipole moments are constructed by using a reliable ab initio data points to carry out the reduced-absorption coefficients k_r(ν, T). This quantum-mechanical investigation have demonstrated that the NaLi profile spectra show a satellite future in the red wing at wavelength λ = 685 nm in the temperature range 4000 K–1.8 × 10~4 K. The computation could also exhibit a second satellite, in the blue wing, near the wavelength λ = 574 nm beyond 6000 K and a third peak located at λ = 490 nm which begins to appear at 1.8 × 10~4 K.

关键词： pressure broadening absorption coefficient satellite structure radiative lifetime