Showing papers by "Sichuan University published in 1990"
TL;DR: In this article, a defocused optical field with a Ronchi grating was used to get a quasi-sine optical field and by using a grating ii phase shifting technique, the fundamental spectrum modulated by the object height distribution was theoretically extended from 0 to 2f0 (f0 is the carrier frequency of the optical field) without overlapping the zero component and other higher spectra.
Abstract: By using a defocused optical field with a Ronchi grating to get a quasi-sine optical field and by using a grating ii phase shifting technique, the fundamental spectrum modulated by the object height distribution can theoretically be extended from 0 to 2f0 ( f0 is the carrier frequency of the optical field) without overlapping the zero component and other higher spectra. Consequently, the measurable slope of height variation can be extended to nearly three times that of the unimproved Fourier transform
profilometry method. This paper gives the theory and experiment results of the improved Fourier transform profilometry.
178 citations
TL;DR: In this paper, cross sections for K-shell ionization by electron impact derived from experimental measurements are tabulated according to target atomic number and incident electron energy, for elements C through U.
62 citations
TL;DR: The relationships between the Hill coefficients and the fractal as well as spectral dimensions of protein molecules are obtained, suggesting a new mechanism for the allosteric effects of proteins and enzymes.
53 citations
48 citations
TL;DR: In this article, the authors investigated linear elastic systems with damping in Hilbert spaces, where A and B are unbounded positive definite linear operators and obtained the most fundamental results for the holomorphic property and exponential stability of the semigroups associated with these systems via inclusion relation of the domains of A and b.
25 citations
TL;DR: The main purpose of this paper is devoted to generalizing the results of Browder[1,2] as discussed by the authors, which consists of four parts: in the first part, we introduce the concepts of multivalued (S) and (S)-type mappings, and in the second part we define the pseudo-degree for (S-) type mappings and the degree for(S)+type mapping, all the generalizations of the degree defined by Browder
Abstract: The main purpose of this paper is devoted to generalizing the results of Browder
[1,2].
This paper consists of four parts. In the first part, we introduce the concepts of multivalued (S) and (S) type mappings and the concepts of the limits of multivalued (S) and (S) type mappings. These kinds of mappings contain many monotone type mappings, such as maximal monotone mapping, bounded pseudo-monotone mapping and bounded generalized pseudo-monotone mapping, as its special cases. In the second part we define the pseudo-degree for (S) type mapping and the degree for (S)
+
type mapping. These two kinds of degrees are all the generalizations of the degree defined by Browder
[1,2].As applications, we utilize the degree theory presented in part 2 to study the existence of solutions for the multivalued operator equations (see part 3) and to obtain some new fixed point theorems in part 4.
25 citations
TL;DR: In this article, a simple and uniform method of calculating the spin-lattice coupling coefficients for all S-state ions in cubic symmetry has been established, and the analytic expressions of the coefficients are given.
Abstract: In this paper a simple and uniform method of calculating the spin-lattice coupling coefficients ${\mathit{G}}_{11}$ and ${\mathit{G}}_{44}$ for all ${\mathit{d}}^{\mathit{n}}$ ions in ${\mathit{T}}_{\mathit{d}}$ symmetry has been established. According to this method, the analytic expressions of ${\mathit{G}}_{11}$ and ${\mathit{G}}_{44}$ for $^{6}$S-state ions based on various mechanisms and models are easily given. Comparing these results with those in ${\mathit{O}}_{\mathit{h}}$ symmetry, it can be seen that, in the two cubic (${\mathit{T}}_{\mathit{d}}$,${\mathit{O}}_{\mathit{h}}$) fields, the signs of the coefficient ${\mathit{G}}_{11}$ or ${\mathit{G}}_{44}$ are opposite for all mechanisms and models, and the ratios ${\mathit{G}}_{11}$/${\mathit{G}}_{44}$ are also rather different for the majority of mechanisms. So, the analogy of coefficients ${\mathit{G}}_{11}$ and ${\mathit{G}}_{44}$ for $^{6}$S-state ions between the two cubic symmetries, such as between ZnTe:${\mathrm{Mn}}^{2+}$ (${\mathit{T}}_{\mathit{d}}$ symmetry) and MgO:${\mathrm{Mn}}^{2+}$ (${\mathit{O}}_{\mathit{h}}$ symmetry) crystals, is not suitable. The expressions for ${\mathit{G}}_{44}$ calculated from two cases are not the same for the covalency and overlap mechanism and the spin-spin mechanism; it appears that the formulas of zero-field splitting (ZFS) D in the trigonal field and E in the rhombic field for the two mechanisms are not self-consistent and need further study. Considering the very scattered and random experimental results of ${\mathit{G}}_{11}$/${\mathit{G}}_{44}$ for $^{6}$S-state ions in the crystals having ${\mathit{T}}_{\mathit{d}}$ symmetry, it seems that a single mechanism cannot explain the ZFS in all symmetries and stress states, and that the relative importance of various mechanisms that contribute to ZFS is not the same in different symmetries and crystals.
21 citations
17 citations
TL;DR: In this article, a dimensionless parameter method was used for studies of second-order reactions, with which the rate constant of reaction can be calculated from the thermogram's data without using the apparatus constants of the calorimeter.
15 citations
TL;DR: In this paper, Lanthanium-modified lead-titanate (PLT) thin films have been prepared for the first time by recently developed multi-ion-beam reactive co-sputtering (MIBRECS) technique.
Abstract: Lanthanium-modified lead-titanate (PLT) thin films have been prepared for the first time by recently developed multi-ion-beam reactive co-sputtering (MIBRECS) technique. The preliminary results of the thin film deposition and analyses studied by X-ray diffraction (XRD) and X-ray photoelectronic spectroscopy (XPS) are presented.
12 citations
TL;DR: In this article, the authors show that the corresponding relation about the normalities of these two spaces does not hold for a certain fuzzy lattice, and they successfully establish a positive result about this normality relation for an important type of fuzzy lattices.
TL;DR: This paper presents a simple practical method for characterizing conformation of protein chains using a single number Df, as the fractal dimension, which is related to the shape of the protein chain.
02 Mar 1990-Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms
TL;DR: In this article, a scaled ion transport cross section is taken as the scaled parameter, and the scatter of the reflection coefficient of the above-mentioned light ions will markedly decrease, and a new empirical formula for the reflection coefficients of light ions is obtained.
Abstract: The reduced energy is normally adopted as the scaled parameter of the reflection coefficient of ions. For H, D, T and He with the same reduced energy, the maximum reflection coefficient of ions is approximately 3 to 4 times as large as the minimum one. We have found that, if the scaled ion transport cross section is taken as the scaled parameter, then the scatter of the reflection coefficient of the above-mentioned light ions will markedly decrease. By adopting this new scaled parameter, we have obtained a new empirical formula for the reflection coefficients of light ions. Compared with the existing empirical formulas for the reflection coefficients of light ions, the new scaling law is much simpler and more universal.
TL;DR: The idea resulting from the present communication suggests that the thermodynamic behaviours of proteins may be related to multifractals.
TL;DR: In this article, the authors introduce the concept of generalized KKM mapping and obtain some general version of the famous K-KM theorem and Ky Fan's minimax inequality.
Abstract: The purpose of this paper is to introduce the concept of generalized KKM mapping and to obtain some general version of the famous KKM theorem and Ky Fan's minimax inequality. As applications, we utilize the results presented in this paper to study the saddle point problem and the existence problem of solutions for a class of quasi-variational inequalities. The results obtained in this paper extend and improve some recent results of [1–6].
TL;DR: By means of the eigenvalues and eigenvectors of the complete energy matrix of the C (d8) ion and the spin Hamiltonian theory, the Spectral fine structure, the EPR parameters (D, g) and the ground state Zeeman splitting of Ni2+ in LiNbO3 are calculated in a unified scheme for the first time as discussed by the authors.
Abstract: By means of the eigenvalues and eigenvectors of the complete energy matrix of the C (d8) ion and the spin Hamiltonian theory, the Spectral fine structure, the EPR parameters (D, g) and the ground state Zeeman splitting of Ni2+ in LiNbO3 are calculated in a unified scheme for the first time. The results agree well with the findings, thus the optical and paramagnetic properties of LiNbO3:Ni2+ are uniformly explained. The theoretical methods, including the g formulae, are suitable for any C (d8,2) ion.
Mittels der Eigenwerte und Eigenvektoren der vollstandigen Energiematrix eines C (d8)-Ions und der Spin-Hamilton-Theorie werden die Feinstruktur, die EPR-Parameter (D, g) und die Zeeman-Aufspaltung des Grundzustandes von Ni2+ in LiNbO3 einheitlich berechnet. Die Ergebnisse sind in Ubereinstimmung mit den Experimenten, so das es moglich ist, die optischen und paramagnetischen Eigenschaften von LiNbO3: Ni2+ einheitlich zu erklaren. Die theoretische Methode und die Formel fur den g-Faktor konnen fur beliebige C (d8,2) Ionen benutzt werden.
TL;DR: In this paper, the electronic structure of Dodecamolybdophophosphates has been analyzed and it was shown that all the component atoms of the anion, P, O p, O b, O t, and Mo, have the potential to participate in catalytic reactions.
Abstract: Dodecamolybdophosphates, which contain the large cluster anion known as the Keggin unit, have been known to be effective catalysts for many heterogeneous oxidation reactions. SCC-DV-Xα calculations have been performed on the electronic structure of the Keggin anion. According to calculated results, all the component atoms of the anion, P,O p ,O b ,O t , and Mo, have the potential to participate in catalytic reactions, which is strongly supported by many experimental results of K. Eguchi and others.
TL;DR: In this paper, a multi-ion-beam reactive co-sputtering (MIBRECS) system and related technique is described, which allows fine control of film stoichiometry and structure, and initial results in preparing lanthanium modified lead titanate (PLT) ferroelectric thin films are given in a companion paper.
Abstract: Co-deposition techniques which allow to control independently the deposition rates of different components during film growth are promising methods for fabricating complex oxide thin films with good quality and ideal stoichiometry. The present work describes a novel multi-ion-beam reactive co-sputtering (MIBRECS) system and related technique, which allows fine control of film stoichiometry and structure. Initial results in preparing lanthanium modified lead titanate (PLT) ferroelectric thin films by using the system are given in a companion paper.
TL;DR: La methode de determination de ces coefficients a partir du spectre optique permet de les expliquer d'une maniere unifiee quand les constantes elastiques locales sont prises en compte as mentioned in this paper.
Abstract: La methode de determination de ces coefficients a partir du spectre optique permet de les expliquer d'une maniere unifiee quand les constantes elastiques locales sont prises en compte
TL;DR: In this article, the reaction of ethyl magnesium bromide and 17 alpha-ethynylestradiol with formaldehyde in the presence of triethyl phosphate or hexamethylphosphoramide gave the 2-and 4-formyl-17 alpha-ETHNylstradiol in high yield.
TL;DR: In this paper, a variety of deposition processes of oxide thin films with emphasis on some new techniques for successful preparation of multi-component ones, illustrate the general trend of the development, and also outline the development of ferroelectric thin films depostion in China.
Abstract: Metal oxide thin films, in particular the multicomponent ones, are being widely used in optoelectronics and other high technological applications. In recent years, several progresses in fabrication of oxide thin films have been made. In this paper, we survey a variety of deposition processes of oxide thin films with emphasis on some new techniques for successful preparation of multi-component ones, illustrate the general trend of the development, and also outline the development of ferroelectric thin films depostion in China.
TL;DR: Methode uniforme de calcul des coefficients G 11 and G 44 a partir des formules de la decomposition de champ nul dans les basses symetries.
Abstract: Methode uniforme de calcul des coefficients G 11 et G 44 a partir des formules de la decomposition de champ nul dans les basses symetries. Cette methode est plus simple que le calcul direct a partir des elements des tenseurs de contrainte
TL;DR: In this paper, the analytical expressions for the spin-lattice coupling coefficients G11 and G44 in cubic symmetry for d8 ions derived from a uniform method based on the relations between the coefficients G 11 and the stress dependence of zero-field splitting were derived.
Abstract: According to the analytic expressions for the spin-lattice coupling coefficients G11 and G44 in cubic symmetry for d8 ions derived from a uniform method based on the relations between the coefficients G 11 and the stress dependence of zero-field splitting, the coefficients G11 and G44 for Ni2+ ions on KMgF3 and KZnF3 crystals have been calculated by using two adjustable parameters (the average covalency) reduction factor N and ligand dipole p) obtained from electron paramagnetic resonance and optical absorption spectra. The absolute values of the calculated results are in agreement with the data obtained from spin-lattice relaxation experiments, and the signs of these coefficients are predicted to be positive from the theoretical calculation.
02 Mar 1990-Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms
TL;DR: PANDA-P as discussed by the authors is a microcomputer program based on a generalized bipartition model of ion transport, which can be used to calculate the range distribution, energy deposition and reflection for different ions that are normally or obliquely incident into a semi-infinite, non-monoatomic solid.
Abstract: PANDA-P is a new microcomputer program based on a generalized bipartition model of ion transport. Owing to using new, better data about elastic scattering cross sections and electronic stopping power and giving up the power-function approximation to these data, the precision of the generalized bipartition model has been largely improved. PANDA-P can be used to calculate the range distribution, energy deposition and reflection for different ions that are normally or obliquely incident into a semi-infinite, nonmonoatomic solid. The computational efficiency for PANDA-P is about 100 times higher than that for the TRIM-86 Monte Carlo program (5000 testing particles for one time Monte Carlo calculation).
03 Dec 1990
TL;DR: In this article, the concept of coincidence point, some coincidence theorems and some existence theorem of solutions of variational inequalities for fuzzy mappings are introduced and established, and the existence theorem of the existence theorem is established.
Abstract: The concept of coincidence point, some coincidence theorems and some existence theorems of solutions of variational inequalities for fuzzy mappings are introduced and established. >
TL;DR: In this article, the authors introduce the concept of accretive mapping in probabilistic normed space (PN space, in short) and study the existence problem of solutions for equations with accrete mappings in PN space.
Abstract: The purpose of this paper is to introduce the concept of accretive mapping in probabilistic normed space (PN space, in short) and to study the existence problem of solutions for equations with accretive mappings in PN space and some existence theorems are shown.
TL;DR: In this article, the spin-lattice coupling coefficients C 11 and C 44 for Cr 3+ ions in various doped YAG crystals have been calculated within the framework of cubic field approximation.
TL;DR: In this article, a uniform and simple method is established to calculate the spin-lattice coupling coefficients G 11 and G 44 for all d n ions in fourfold or eightfold cubic coordination from the formulas of zero-field splitting in tetragonal and trigonal symmetries.
TL;DR: In this article, an exothermic binary chemical reaction of first order was studied, assuming that one of the reactants can undergo a change of phase, and the well-posedness of the corresponding system of two parabolic equations with a free boundary was proved in a classical sense.
Abstract: An exothermic binary chemical reaction of first order is studied, assuming that one of the reactants can undergo a change of phase. In the limit of low activation energy, a one-dimensional problem is considered and the well-posedness of the corresponding system of two parabolic equations with a free boundary is proved in a classical sense.
TL;DR: Etude theorique des coefficients (G 11'and G 44 ') pour des ions d 5 dans une symetrie T d. Application aux 6 coefficients de couplage G ij de Mn 2+ par rotation de l'axe cubique vers l 'axe wurtzite as mentioned in this paper.
Abstract: Etude theorique des coefficients (G 11 ' et G 44 ') pour des ions d 5 dans une symetrie T d . Application aux 6 coefficients de couplage G ij de Mn 2+ par rotation de l'axe cubique vers l'axe wurtzite