Pub Date : 1990-10-01DOI: 10.1051/JPHYS:0199000510200234700
I. Voigt-martin, H. Krug, D. Dyck
Les images de microscopie electronique a haute resolution des polymeres cristaux liquides calamitiques [CO−CH(R)−CO 2 −(CH 2 ) 6 −OPh−N:N−PhO−(CH 2 ) 6 −O] n (R=CH 2 −CH=CH 2 , (CH 2 ) 6 −O−Ph N=N−Ph−CN) et discotique poly (hexadecanedioate de triphenylene) sont simulees sur ordinateur et comparees avec les structures obtenues a partir des resultats experimentaux de diffraction electronique. Une theorie est developpee pour expliquer le bon accord observe
了电子显微镜的图像的高分辨率液晶聚合物calamitiques [CO 2−−−CH (R) CO (CH) 2−6碳化硅N: N−−和光化学6−−(CH) O] N (R = 2−CH = CH、CH (CH) O - 6−−Ph = N (N−−CN)和discotique聚hexadecanedioate triphenylene)是计算机上和simulees费用包括与所得到的结构起了电子衍射的实验结果。发展了一个理论来解释观察到的良好一致性
{"title":"High resolution electron microscopy of liquid crystalline polymers","authors":"I. Voigt-martin, H. Krug, D. Dyck","doi":"10.1051/JPHYS:0199000510200234700","DOIUrl":"https://doi.org/10.1051/JPHYS:0199000510200234700","url":null,"abstract":"Les images de microscopie electronique a haute resolution des polymeres cristaux liquides calamitiques [CO−CH(R)−CO 2 −(CH 2 ) 6 −OPh−N:N−PhO−(CH 2 ) 6 −O] n (R=CH 2 −CH=CH 2 , (CH 2 ) 6 −O−Ph N=N−Ph−CN) et discotique poly (hexadecanedioate de triphenylene) sont simulees sur ordinateur et comparees avec les structures obtenues a partir des resultats experimentaux de diffraction electronique. Une theorie est developpee pour expliquer le bon accord observe","PeriodicalId":14747,"journal":{"name":"Journal De Physique","volume":"51 1","pages":"2347-2371"},"PeriodicalIF":0.0,"publicationDate":"1990-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87966752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1990-10-01DOI: 10.1051/JPHYS:0199000510190218700
D. Léger, C. Deutsch
This is the first paper in a series devoted to a systematic investigation of linear electronic transport properties in strongly coupled plasmas consisting of a multicomponent and classical ionic mixture embbedded in a highly degenerate electron jellium. The basic formalism rests upon suitable extensions of the Boltzmann-Ziman theory as explained in this work. It is hereafter specialized in a thorough investigation of thermoelectronic and mechanical transport coefficients. Validity conditions for the Lorentzian approximation are first carefully examined. High temperature and inelastic corrections are emphasized. Basic transport quantities are expressed under an analytic and compact form both in the elastic and i Cet article est le premier d'une serie consacree a l'etude systematique du transport electronique lineaire dans les plasmas denses fortement couples, comportant plusieurs especes ioniques classiques plongees dans un jellium electronique fortement degenere. Le formalisme retenu, specialise ici au cas des coefficients thermoelectroniques et du transport mecanique (viscosite), repose pour l'essentiel sur l'extension de la theorie de Boltzmann-Ziman, dans le cadre de l'approximation Lorentzienne. Les conditions de validite de cette derniere sont largement developpees, et l'accent mis sur les corrections de temperature finies et les corrections inelastiques. Les coefficients de transport sont exprimes analytiquement sous forme de quantites reduites, a la fois dans le cas elastique et inelastique, respectivement au moyen des solutions exactes et variationnelles de l'equation de transport. Ceci permet un calcul simplifie des corrections precedemment mentionnees, calcul qui sera detaille dans l'article II de cette serie. Finalement, nous demontrons la validite de la methode en reproduisant, dans les limites appropriees, les formules de Ziman et d'Edwards pour la resistivite, ainsi que d'autres resultats bien connus
这是一系列致力于系统研究强耦合等离子体中线性电子输运性质的论文中的第一篇，强耦合等离子体由嵌入在高度简并电子凝胶中的多组分和经典离子混合物组成。基本的形式主义建立在玻尔兹曼-齐曼理论的适当扩展之上，正如本著作所解释的那样。此后，它专门从事热电子和机械输运系数的深入研究。首先仔细考察了洛伦兹近似的有效性条件。强调了高温和非弹性修正。基本输运量在弹性和弹性两种情况下均以解析和紧致形式表示。文章est le premier d'une serie consacree al 'etude systematique du transport electronique lineaire dans les等离子体密度和位移偶，重要的plusiurs especespecioniques classiques plongees dans un jilium electronique forement degenere。形式主义的保留，专门研究热电子系数和输运力学(粘滞)，玻尔兹曼-齐曼理论的基本原理和扩展，洛伦兹安近似理论的基本原理。在较大的发展过程中，较低的条件下可以有效地测量温度，较低的条件下可以精确地测量温度，较低的条件下可以精确地测量弹性。输运系数和输运方程的实验分析结果分别为:弹性和非弹性，分别为弹性和非弹性，分别为弹性和非弹性。Ceci许可的计算简化了前面提到的更正，计算的细节不符合第II条的规定。最后，我们证明了复制方法的有效性，限制了适当性，Ziman和d'Edwards的公式为电阻性，而结果为一致性
{"title":"Linear electronic transport in dense plasmas. I. Specific features of Boltzmann-Ziman formalism within the Lorentzian approximation","authors":"D. Léger, C. Deutsch","doi":"10.1051/JPHYS:0199000510190218700","DOIUrl":"https://doi.org/10.1051/JPHYS:0199000510190218700","url":null,"abstract":"This is the first paper in a series devoted to a systematic investigation of linear electronic transport properties in strongly coupled plasmas consisting of a multicomponent and classical ionic mixture embbedded in a highly degenerate electron jellium. The basic formalism rests upon suitable extensions of the Boltzmann-Ziman theory as explained in this work. It is hereafter specialized in a thorough investigation of thermoelectronic and mechanical transport coefficients. Validity conditions for the Lorentzian approximation are first carefully examined. High temperature and inelastic corrections are emphasized. Basic transport quantities are expressed under an analytic and compact form both in the elastic and i Cet article est le premier d'une serie consacree a l'etude systematique du transport electronique lineaire dans les plasmas denses fortement couples, comportant plusieurs especes ioniques classiques plongees dans un jellium electronique fortement degenere. Le formalisme retenu, specialise ici au cas des coefficients thermoelectroniques et du transport mecanique (viscosite), repose pour l'essentiel sur l'extension de la theorie de Boltzmann-Ziman, dans le cadre de l'approximation Lorentzienne. Les conditions de validite de cette derniere sont largement developpees, et l'accent mis sur les corrections de temperature finies et les corrections inelastiques. Les coefficients de transport sont exprimes analytiquement sous forme de quantites reduites, a la fois dans le cas elastique et inelastique, respectivement au moyen des solutions exactes et variationnelles de l'equation de transport. Ceci permet un calcul simplifie des corrections precedemment mentionnees, calcul qui sera detaille dans l'article II de cette serie. Finalement, nous demontrons la validite de la methode en reproduisant, dans les limites appropriees, les formules de Ziman et d'Edwards pour la resistivite, ainsi que d'autres resultats bien connus","PeriodicalId":14747,"journal":{"name":"Journal De Physique","volume":"17 1","pages":"2187-2203"},"PeriodicalIF":0.0,"publicationDate":"1990-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90758169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1990-10-01DOI: 10.1051/JPHYS:0199000510190215300
R. Rammal, J. Bellissard
The energy of 2D Bloch electrons in a magnetic field is studied as a function of the filling fractions ν and the magnetic flux φ. Using a new semi-classical quantization method the total energy E(φ,ν) is calculated and shown to have an absolute minimum which corresponds to one flux quantum per particle. This optimal flux phenomenon is shown to occur under large conditions and for different lattices. An explicit cusp-like behavior of E vs. φ at fixed ν is found both for the absolute and for the relative minima of E. Furthermore, the ground state energy is shown to be a smooth function of ν. The implications of our results for the stabilization of Anyons and the flux states are discussed On etudie l'energie des electrons de Bloch sous champ magnetique en fonction du flux magnetique φ et du taux de remplissage ν. On calcule l'energie totale E (φ,ν) a l'aide d'une nouvelle methode de quantification semi-classique. Le minimum absolu est atteint pour un choix optimal d'un quantum de flux par particule. Ce phenomene se produit pour differents reseaux et sous des conditions assez generales. Pour ν fixe, l'energie est une ligne brisee en fonction de φ. Toutefois, l'energie du fondamental est une fonction reguliere de ν. Les implications de ces resultats pour la stabilisation des Anyons et les phases de flux sont discutees
{"title":"Ground state of the Fermi gas on 2D lattices with a magnetic field","authors":"R. Rammal, J. Bellissard","doi":"10.1051/JPHYS:0199000510190215300","DOIUrl":"https://doi.org/10.1051/JPHYS:0199000510190215300","url":null,"abstract":"The energy of 2D Bloch electrons in a magnetic field is studied as a function of the filling fractions ν and the magnetic flux φ. Using a new semi-classical quantization method the total energy E(φ,ν) is calculated and shown to have an absolute minimum which corresponds to one flux quantum per particle. This optimal flux phenomenon is shown to occur under large conditions and for different lattices. An explicit cusp-like behavior of E vs. φ at fixed ν is found both for the absolute and for the relative minima of E. Furthermore, the ground state energy is shown to be a smooth function of ν. The implications of our results for the stabilization of Anyons and the flux states are discussed On etudie l'energie des electrons de Bloch sous champ magnetique en fonction du flux magnetique φ et du taux de remplissage ν. On calcule l'energie totale E (φ,ν) a l'aide d'une nouvelle methode de quantification semi-classique. Le minimum absolu est atteint pour un choix optimal d'un quantum de flux par particule. Ce phenomene se produit pour differents reseaux et sous des conditions assez generales. Pour ν fixe, l'energie est une ligne brisee en fonction de φ. Toutefois, l'energie du fondamental est une fonction reguliere de ν. Les implications de ces resultats pour la stabilisation des Anyons et les phases de flux sont discutees","PeriodicalId":14747,"journal":{"name":"Journal De Physique","volume":"19 1","pages":"2153-2165"},"PeriodicalIF":0.0,"publicationDate":"1990-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79123506","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1990-10-01DOI: 10.1051/JPHYS:0199000510200230700
P. Higgs, J. Joanny
Lamellar phases formed by amphiphilic molecules consist of a stack of alternating solvent layers and surfactant membranes. The stability of the structure is governed by the interactions between neighboring membranes mediated by the solvent layers, these interactions include the Van der Waals attractive forces, the hydration forces and the electrostatic forces. It was argued by Helfrich [1] that due to the very low surface tensions, the out-of-plane undulations of the membrane are important and induce a repulsion of entropic origin between membranes. The strength of the undulation repulsion is controlled by the bending elasticity of the membranes that is usually described, by the bending constants kc and kc for the mean and Gaussian curvatures.
{"title":"Enhanced membrane rigidity in charged lamellar phases","authors":"P. Higgs, J. Joanny","doi":"10.1051/JPHYS:0199000510200230700","DOIUrl":"https://doi.org/10.1051/JPHYS:0199000510200230700","url":null,"abstract":"Lamellar phases formed by amphiphilic molecules consist of a stack of alternating solvent layers and surfactant membranes. The stability of the structure is governed by the interactions between neighboring membranes mediated by the solvent layers, these interactions include the Van der Waals attractive forces, the hydration forces and the electrostatic forces. It was argued by Helfrich [1] that due to the very low surface tensions, the out-of-plane undulations of the membrane are important and induce a repulsion of entropic origin between membranes. The strength of the undulation repulsion is controlled by the bending elasticity of the membranes that is usually described, by the bending constants kc and kc for the mean and Gaussian curvatures.","PeriodicalId":14747,"journal":{"name":"Journal De Physique","volume":"365 1","pages":"2307-2320"},"PeriodicalIF":0.0,"publicationDate":"1990-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76558464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1990-10-01DOI: 10.1051/JPHYS:0199000510190213500
G. Aguirre-Zamalloa, M. Couzi, N. Chanh, B. Gallois
The ferroelectric phase transition in (CH 3 ) 4 NCdBr 3 (TMCB) at ∼156 K is studied by X-ray diffraction measurements; it is shown that the space group of the paraelectric phase is P6 3 /m, with lattice parameters a, a, c, and that of the ferroelectric phase is P6 1 (or P6 5 ) with lattice parameters a, a, 3c. The transition is analyzed in the framework of the Landau theory. In particular, the observed symmetry change implies the presence of cubic invariants (first-order transition). A classical Landau type expansion of the free-energy, including coupling terms with the polarization vector components (improper ferroelectric) is able to account satisfactorily for the temperature dependence of the spontaneous polarization and dielectric susceptibilities which have been previously measured La transition de phase ferroelectrique de (CH 3 ) 4 NCdBr 3 (TMCB) a ∼156 K est etudiee par diffraction des rayons X; on montre que le groupe d'espace de la phase paraelectrique est P6 3 /m, avec des parametres de maille a, a, c, et que celui de la phase ferroelectrique est P6 1 (ou P6 5 ) avec pour parametres a, a, 3c. La transition est analysee a l'aide de la theorie de Landau. En particulier, le changement de symetrie observe implique l'existence d'invariants d'ordre trois (transition du premier ordre). Un developpement classique de l'energie libre de Landau, incluant les termes de couplage avec les composantes du vecteur polarisation (ferroelectrique impropre) rend compte d'une maniere satisfaisante de la dependance en temperature de la polarisation spontanee et des susceptibilites dielectriques, mesurees precedemment
用x射线衍射测量研究了(ch3) 4 NCdBr 3 (TMCB)在~ 156 K下的铁电相变;结果表明，准电相的空间群为p63 /m，晶格参数为a、a、c;铁电相的空间群为p61(或p65)，晶格参数为a、a、3c。在朗道理论的框架下分析了这种转变。特别是，观察到的对称性变化意味着三次不变量(一阶跃迁)的存在。自由能的经典朗道式展开，包括与极化矢量分量的耦合项(不适当的铁电)，能够令人满意地解释自发极化和介电率的温度依赖性，这是先前测量到的La相变铁电de (ch3) 4 NCdBr 3 (TMCB) A ~ 156 K的衍射衍射des rayons X;对每组相铁电试验p6.3 /m，每组相铁电试验p6.1 /m，每组相铁电试验p6.1 /m(每组p6.5 /m)，每组铁电试验参数a, a, c，每组铁电试验参数a, a, 3c。过渡性分析是朗道理论的基础。特别地，这些对称的变化观察到简单的存在性、不变性和三阶性(初阶跃迁)。发展经典的朗道自由能量，包括耦合条件、矢量极化条件、复合材料条件(铁电性改进)、温度、极化自发条件和磁化介质条件下的电依赖性、测量方法等
{"title":"On the ferroelectric phase transition in (CH3)4 NCdBr 3 (TMCB)","authors":"G. Aguirre-Zamalloa, M. Couzi, N. Chanh, B. Gallois","doi":"10.1051/JPHYS:0199000510190213500","DOIUrl":"https://doi.org/10.1051/JPHYS:0199000510190213500","url":null,"abstract":"The ferroelectric phase transition in (CH 3 ) 4 NCdBr 3 (TMCB) at ∼156 K is studied by X-ray diffraction measurements; it is shown that the space group of the paraelectric phase is P6 3 /m, with lattice parameters a, a, c, and that of the ferroelectric phase is P6 1 (or P6 5 ) with lattice parameters a, a, 3c. The transition is analyzed in the framework of the Landau theory. In particular, the observed symmetry change implies the presence of cubic invariants (first-order transition). A classical Landau type expansion of the free-energy, including coupling terms with the polarization vector components (improper ferroelectric) is able to account satisfactorily for the temperature dependence of the spontaneous polarization and dielectric susceptibilities which have been previously measured La transition de phase ferroelectrique de (CH 3 ) 4 NCdBr 3 (TMCB) a ∼156 K est etudiee par diffraction des rayons X; on montre que le groupe d'espace de la phase paraelectrique est P6 3 /m, avec des parametres de maille a, a, c, et que celui de la phase ferroelectrique est P6 1 (ou P6 5 ) avec pour parametres a, a, 3c. La transition est analysee a l'aide de la theorie de Landau. En particulier, le changement de symetrie observe implique l'existence d'invariants d'ordre trois (transition du premier ordre). Un developpement classique de l'energie libre de Landau, incluant les termes de couplage avec les composantes du vecteur polarisation (ferroelectrique impropre) rend compte d'une maniere satisfaisante de la dependance en temperature de la polarisation spontanee et des susceptibilites dielectriques, mesurees precedemment","PeriodicalId":14747,"journal":{"name":"Journal De Physique","volume":"54 1","pages":"2135-2141"},"PeriodicalIF":0.0,"publicationDate":"1990-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73895311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1990-10-01DOI: 10.1051/JPHYS:0199000510200233300
F. Nallet, D. Roux, S. Milner
2014 Small-angle neutron scattering experiments on dilute lyotropic smectics A have been performed on oriented samples. The structure factor of a two-component smectic A is derived theoretically, taking explicitly into account the anisotropic coupling between concentration and layer displacement fluctuations. The anisotropic small-angle signal and other characteristic features of the spectra, and their evolutions with dilution, are predicted. The differences between electrostatically and sterically stabilized dilute lamellar phases are emphasized. Experiments are consistently described by the theory. J. Phys. France 51 (1990) 2333-2346 15 OCTOBRE 1990, 1
{"title":"Small-angle scattering features of lyotropic smectics A","authors":"F. Nallet, D. Roux, S. Milner","doi":"10.1051/JPHYS:0199000510200233300","DOIUrl":"https://doi.org/10.1051/JPHYS:0199000510200233300","url":null,"abstract":"2014 Small-angle neutron scattering experiments on dilute lyotropic smectics A have been performed on oriented samples. The structure factor of a two-component smectic A is derived theoretically, taking explicitly into account the anisotropic coupling between concentration and layer displacement fluctuations. The anisotropic small-angle signal and other characteristic features of the spectra, and their evolutions with dilution, are predicted. The differences between electrostatically and sterically stabilized dilute lamellar phases are emphasized. Experiments are consistently described by the theory. J. Phys. France 51 (1990) 2333-2346 15 OCTOBRE 1990, 1","PeriodicalId":14747,"journal":{"name":"Journal De Physique","volume":"73 1","pages":"2333-2346"},"PeriodicalIF":0.0,"publicationDate":"1990-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76040930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1990-10-01DOI: 10.1051/JPHYS:0199000510200232100
H. Mattoussi
Etude du polyelectrolyte (Ph−CHR−CH 2 ) n (R= + SC 4 H 8 ) en solution aqueuse. En l'absence de sel, on observe 2 modes de fluctuations, un mode cooperatif et un mode a longue distance, ce qui reflete une conformation allongee du polyelectrolyte. L'augmentation de la force ionique de la solution entraine une reduction de la conformation et un seul mode de fluctuation est observable. Le coefficient de diffusion mutuelle ne depend pas des concentrations nen polymere et en sel en raison des interactions hydrophobes
水溶液中聚电解质(Ph−CHR−ch2) n (R= + sc4h 8)的研究。在没有盐的情况下，观察到两种波动模式，一种是合作模式，另一种是远距离模式，反映了聚电解质的拉长构象。溶液离子强度的增加导致构象的降低，只能观察到一种波动模式。由于疏水相互作用，相互扩散系数不依赖于聚合物和盐的浓度
{"title":"Unusual behavior of water soluble polyelectrolyte macromolecules shown by QELS study: is it a property of hydrophobic backbones ?","authors":"H. Mattoussi","doi":"10.1051/JPHYS:0199000510200232100","DOIUrl":"https://doi.org/10.1051/JPHYS:0199000510200232100","url":null,"abstract":"Etude du polyelectrolyte (Ph−CHR−CH 2 ) n (R= + SC 4 H 8 ) en solution aqueuse. En l'absence de sel, on observe 2 modes de fluctuations, un mode cooperatif et un mode a longue distance, ce qui reflete une conformation allongee du polyelectrolyte. L'augmentation de la force ionique de la solution entraine une reduction de la conformation et un seul mode de fluctuation est observable. Le coefficient de diffusion mutuelle ne depend pas des concentrations nen polymere et en sel en raison des interactions hydrophobes","PeriodicalId":14747,"journal":{"name":"Journal De Physique","volume":"2008 1","pages":"2321-2332"},"PeriodicalIF":0.0,"publicationDate":"1990-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86231639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1990-10-01DOI: 10.1051/JPHYS:0199000510190220500
E. Aero, S. Vakulenko, A. Vilesov
A semiphenomenological theory that has the advantage of taking into account nonlinear and nonlocal contributions in the free energy for microphase separation of block copolymers is proposed. A kinetic nonlinear equation defining the process of structure formation from a melt is obtained, and its analytical solution at the melt-structure transition temperature is examined. In this region, the structure formation proceeds in two stages. The first one is characterized by damping of all but stable Fourier-components of density distribution and the second, by stabilization of the amplitude of the distribution. Characteristic times of these processes are estimated. The applied approach allows a comparatively simple definition of lamellar, hexagonal and body-centered cubic structures near Ts. Equilibrium structures at T ~ Ts are described as well.
{"title":"Kinetic theory of microphase separation in block copolymers","authors":"E. Aero, S. Vakulenko, A. Vilesov","doi":"10.1051/JPHYS:0199000510190220500","DOIUrl":"https://doi.org/10.1051/JPHYS:0199000510190220500","url":null,"abstract":"A semiphenomenological theory that has the advantage of taking into account nonlinear and nonlocal contributions in the free energy for microphase separation of block copolymers is proposed. A kinetic nonlinear equation defining the process of structure formation from a melt is obtained, and its analytical solution at the melt-structure transition temperature is examined. In this region, the structure formation proceeds in two stages. The first one is characterized by damping of all but stable Fourier-components of density distribution and the second, by stabilization of the amplitude of the distribution. Characteristic times of these processes are estimated. The applied approach allows a comparatively simple definition of lamellar, hexagonal and body-centered cubic structures near Ts. Equilibrium structures at T ~ Ts are described as well.","PeriodicalId":14747,"journal":{"name":"Journal De Physique","volume":"28 1","pages":"2205-2226"},"PeriodicalIF":0.0,"publicationDate":"1990-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78738260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1990-10-01DOI: 10.1051/JPHYS:0199000510190216700
A. Barelli, J. Bellissard, R. Rammal
Algebraic methods recently introduced for 2D Bloch electrons in a uniform magnetic field are extended to the case of periodic magnetic fields. Using a semiclassical approach, we investigate the case where the magnetic unit cell is commensurate with the lattice unit cell. In general and according to the values φ of the average flux through the magnetic unit cell, two distinct cases take place. The first one corresponds to finite values of φ, where the usual structure of Landau levels is recovered (non commutative case). In the second case where φ=0, a non trivial band structure is obtained (commutative case). Our results are illustrated by simple examples. In particular we show that, under certain conditions, the mechanism of stabilization of the Fermi sea by the gaps (with one quantum flux per fermion) holds in the general case of periodic magnetic fields Les methodes algebriques que l'on a introduites recemment pour l'etude des electrons de Bloch sous champ magnetique uniforme sont generalisees au cas des champs periodiques. En utilisant une approche semi-classique, on etudie le cas ou la maille magnetique uniforme sont generalisees au cas des champs periodiques. En utilisant une approche semi-classique, on etudie le cas ou la maille magnetique est commensurable avec celle du reseau. En general et selon la valeur φ du flux magnetique moyen a travers la cellule elementaire, deux cas distincts semblent se distinguer. Le premier cas est φ¬=0, ou la structure en niveaux de Landau est retrouvee (cas non commutatif). Dans le second cas φ=0, on obtient une structure de bandes non triviale (cas commutatif). Nos resultats sont illustres avec des exemples simples. En particulier on montre, sous certaines conditions, que le mecanisme de stabilisation de la mer de Fermi, avec un quantum de flux par fermion, se generalise au cas d'un champ magnetique periodique
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Pub Date : 1990-10-01DOI: 10.1051/JPHYS:0199000510200229300
J. Garreau, M. Allegrini, L. Julien, F. Biraben
Résumé. - Cet article le d’une donnant une description détaillée de notre mesure récente de la constante de Rydberg. Nous y décrivons soigneusement la méthode de mesure des longueurs d’onde. Les longueurs d’onde des trois transitions A deux photons 2S-8D, 2S-10D et 2S-12D dans l’hydrogène et le deutérium sont comparées à celle d’un laser He-Ne stabilisé sur l’iode, laser qui est actuellement la meilleure référence dans le domaine optique. Cette comparaison est faite à l’aide d’un étalon Fabry-Perot de grande stabilité. Les déphasages à la réflexion sont pris en compte en changeant la longueur de cette cavité ("méthode des miroirs virtuels"). Pour mesurer le déphasage de Fresnel nous étudions la différence de fréquence entre le premier mode transverse et le mode fondamental de cette cavité. A partir des six longueurs d’onde mesurées, nous déduisons une nouvelle valeur de la constante de Rydberg R~ = 109737, la plus précise à l’heure actuelle. A partir des déplacements isotopiques entre l’hydrogène et le deutérium nous déduisons aussi une valeur pour le rapport de masse entre le proton et l’électron: mp/me Abstract. 2014 This paper is the last of a series giving a detailed description of our recent determi- nation of the Rydberg constant. Here we carefully describe the wavelength comparison procedure. The wavelengths of the three two-photon transitions 2S-8D, 2S-10D, and 2S-12D in hydrogen and deuterium are compared to that of an I2-stabilized He-Ne laser which is the present best reference in the optical domain. The key of this comparison is a high stability Fabry-Perot cavity etalon. The reflective phase shifts are taken into account by changing the length of this cavity ("virtual mirrors method"). In order to measure the Fresnel phase shift we study the frequency difference between the first transverse mode and the fundamental mode of the cavity. From the six measured wavelengths we deduce a new value for the Rydberg constant, R~ = 109737.315709(18) cm-1, currently the most precise one. The H-D isotopic shifts have been also measured and a value for the proton-to-electron mass ratio is deduced: mp/me = 1836.15259(24).
摘要。-这篇文章详细描述了我们最近对里德伯格常数的测量。我们仔细地描述了测量波长的方法。将氢和氘中三种2S-8D、2S-10D和2S-12D双光子跃迁的波长与碘稳定的He-Ne激光器的波长进行了比较，后者是目前光学领域的最佳参考。这种比较是用一种非常稳定的法布里-佩罗种马进行的。反射时的相移是通过改变腔的长度来考虑的(“虚拟镜像法”)。为了测量菲涅耳相移，我们研究了这个腔的第一横向模态和基本模态之间的频率差异。从测量的6个波长中，我们推导出了里德伯格常数R~ = 109737的新值，这是目前最精确的值。从氢和氘之间的同位素位移，我们也推导出质子和电子之间质量比的值:mp/me Abstract. 2014这篇论文是系列论文的最后一篇，详细描述了我们最近确定的里德伯格常数。这里我们仔细描述波长比较程序。wavelengths of The three two-photon 2S-8D跃迁、2S-10D and 2S-12D are in and氘氢比较to that of an I2-stabilized氖激光which is礼物in The best参考的光学域。= =地理= =根据美国人口普查，这个县的面积为。are The文件阶段变化过程中博取by changing The长of this隔热”(virtual mirrors法”)。为了测量菲涅耳相移，我们研究了腔体第一横模和基本模之间的频差。= =地理= =根据美国人口普查，这个县的面积为，其中土地面积为，其中土地面积为。H-D同位素位移也被测量，并推导出质子对电子质量比的值:mp/me = 1836.15259(24)。
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