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

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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

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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

Balance control during gait initiation: State-of-the-art and research perspectives

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World Journal of Orthopedics 2017年第11期8卷 815-828页

作者： Eric Yiou Teddy Caderby Arnaud Delafontaine Paul Fourcade Jean-Louis Honeine laboratoire CIAMS Université Paris-Sud Université Paris-Saclay laboratoire CIAMS Université d’Orléans laboratoire irisse UFR des Sciences de l’Homme et de l’Environnement Université de la Réunion Ecole Nationale de Kinésithérapie et Rééducation Department of Public Health Experimental and Forensic Medicine University of Pavia

It is well known that balance control is affected by aging, neurological and orthopedic conditions. Poor balance control during gait and postural maintenance are associated with disability, falls and increased mortality. Gait initiation-the transient period between the quiet standing posture and steady state walking-is a functional task that is classically used in the literature to investigate how the central nervous system(CNS) controls balance during a whole-body movement involving change in the base of support dimensions and center of mass progression. Understanding how the CNS in able-bodied subjects exerts this control during such a challenging task is a prerequisite to identifying motor disorders in populations with specific impairments of the postural system. It may also provide clinicians with objective measures to assess the efficiency of rehabilitation programs and better target interventions according to individual impairments. The present review thus proposes a state-of-the-art analysis on:(1) the balance control mechanisms in play during gait initiation in able bodied subjects and in the case of some frail populations; and(2) the biomechanical parameters used in the literature to quantify dynamic stability during gait initiation. Balance control mechanisms reviewed in this article included anticipatory postural adjustments, stance leg stiffness, foot placement, lateral ankle strategy, swing foot strike pattern and vertical center of mass braking. Based on this review, the following viewpoints were put forward:(1) dynamic stability during gait initiation may share a principle of homeostatic regulation similar to most physiological variables, where separate mechanisms need to be coordinated to ensure stabilization of vital variables, and consequently; and(2) rehabilitation interventions which focus on separate or isolated components of posture, balance, or gait may limit the effectiveness of current clinical practices.

关键词： Balance control Anticipatory postural adjustments Leg stiffness Foot placement Lateral ankle strategy Foot strike pattern Vertical center of mass braking Dynamic stability Gait initiation Biomechanics

PHONONS IN POLYACENIC CHAINS

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维普期刊数据库

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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

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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

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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

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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

The Stochastic Regression Analysis as a Tool in Ecotoxicological QSAR Studies

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Biomedical and Environmental Sciences 1989年第4期2卷 385-393页

作者： J.DEVILLERS D.ZAKARYA M.CHASTRETTE J.C.DORE CTIS laboratoire

Correspondence factor analysis(CFA)was used in conjunction with linear regression analysis to examine the structure-activity relationships of 50 benzene derivatives tested on Pimephales *** nine molecular descriptors(numbers of C,H,O,N,Br,Cl,NO_2,OH,and NH_2 included in the molecules),CFA made it possible to define five new independent variables which were introduced in a stepwise regression analysis procedure to describe the acute toxicity(96-h LC_(50))of the aromatic *** model log 1/C=-0.727F_1+1.248F_3+4.052(r=0.918; s=0.270)is more relevant to describe the ecotoxicological behavior of the studied compounds on the fathead minnow than that obtained with principal components(log 1/C=0.151 PC_1 -0.271 PC_2+4.124;r=0.737;s=0.460).The heuristic potency of this particular statistical analysis,which is called stochastic regression analysis,is discussed in detail.1989 Academic Press,Inc.

关键词： QSAR The Stochastic Regression Analysis as a Tool in Ecotoxicological QSAR Studies

The xanthate route to all-carbon quaternary centers

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Science China Chemistry 2019年第11期62卷 1450-1462页

作者： Béatrice Quiclet-Sire Samir Z.Zard laboratoire de Synthèse Organique Ecole Polytechnique

This review discusses the numerous routes to all-carbon quaternary centers based on the unique radical chemistry of xanthates. Itsummarizes the various approaches to the synthesis of tertiary xanthates then describes the intra- and intermolecular radicaladditions and combinations thereof that have so far been used to construct quaternary centers.

关键词： xanthates quaternary centers radical addition cyclization tandem reactions