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Showing papers by "Sichuan University published in 1982"


Journal ArticleDOI
Wan-Di Wei1
TL;DR: A lower bound to the cardinality of the class A(R, S), which can be computed readily, is derived.

23 citations


Journal ArticleDOI
TL;DR: In this paper, the authors investigated periodic solutions for a coupled system of parabolic boundary value problems in a one-dimensional domain under various boundary conditions, including Dirichlet type boundary conditions.
Abstract: THE STUDY of periodic solutions to parabolic differential systems goes back to J. Fourier who investigated the linear heat equation for the determination of temperature oscillation on earth (cf. [ 141). In recent years, attention has been given to nonlinear parabolic boundary value problems (cf. [l, 2,4, 6, 7, 15, 16)). However, most of the discussions in the literature are concerned with a single parabolic equation under Dirichlet type boundary condition. Due to the recent development in the biochemical and biological fields there arise various types of reactiondiffusion systems (e.g., see [lO-121). An interesting problem in some of these systems, such as the Belousov-Zhabotinskii reaction model, is an understanding of the oscillating nature of the solution. In this paper, we investigate periodic solutions for a coupled system of parabolic boundary value problems in a one-dimensional domain under various boundary conditions. Specifically, the equations under consideration are given by

15 citations


Journal ArticleDOI
Ru-gang Xie1, Li-sen Deng1, Hai-quan Gu1, Ya-ming Fan1, Hua-ming Zhao1 
01 Oct 1982-Steroids
TL;DR: A new two-step synthetic route to 2-hydroxy estrogens from either estrone or estradiol, via 2-acetylation followed by Dakin oxidation, is described, characterized by its simplicity and excellence of yield.

15 citations


Journal ArticleDOI
Zhou Hao-Xuan1
TL;DR: In this article, it was shown that every Hausdorff compact space with a small (resp. regularly small) diagonal is metrizable under CH+FA, but no G δ -diagonal spaces are given under MA+¬CH.

11 citations


Journal ArticleDOI
TL;DR: In response to enquiries received by the World Health Organization from several countries, the WHO Special Program of Research, Development and Research Training in Human Reproduction convened a meeting of experts in Geneva during August 1981 to review the available animal, clinical, and epidemiological data on vasectomy.

5 citations


Journal ArticleDOI
Xu-hua Zheng1, Wen-long Wang1, Zhi-zheng Zhong1, Zhen-bon Xu1, Hua-ming Zhao1 
01 Aug 1982-Steroids
TL;DR: A novel synthetic route to pyrogallolestrogen dimethyl ethers was developed using Benzo-15-crown-5 with CuI that catalyses the specific nucleophilic substitution of bromo atoms by methoxide ions.

5 citations


Journal ArticleDOI
Li Delang1
01 Jul 1982
TL;DR: In this article, it was shown that two positive definite binary forms with real coefficients are equivalent if they represent the same numbers, with the sole exception of the pair equivalent to and their scalings.
Abstract: It is an old problem whether two binary quadratic forms representing the same numbers are equivalent. Legendre asserted without proof that two positive definite forms representing the same numbers are equivalent. In 1895, Bauer(1) proved Legendre's assertion for primitive forms with the same discriminant. In 1938 Delone (2) proved that two positive definite binary forms with real coefficients are equivalent if they represent the same numbers, with the sole exception of the pair equivalent to and their scalings. Watson (3) rediscovered this result in 1979 and asked the same question for indefinite binary forms.

3 citations


Journal ArticleDOI
01 Jan 1982-Vacuum
TL;DR: In this paper, it has been shown that the molecular conductance of an elbow, the correction factor and the transmission probability are all functions of the supplementary angle between the two tubes.

2 citations


Jiang D1
01 Jan 1982
TL;DR: The Encyrtid parasites found in the males and females of Ericerus pela Chav from China are reported, with one species, Microterys sinicus, described as new to science, and all the others, Metaphycus tama-katakaigara Tachikawa, Blastothrix ericeri Sugonjaev and C. similis Ishii are new records to the Chinese insect fauna.
Abstract: The present paper reports the Encyrtid parasites found in the males and femalesof Ericerus pela Chav.from China. Altogether six species are recognized. Amongthem, one species, Microterys ericeri Ishii,is already known in China, another species,Microterys sinicus, is described as new to science,and all the others, Metaphycus tama-katakaigara Tachikawa, Blastothrix ericeri Sugonjaev, Cerapteroceroides japonicus Ash-mead and C. similis Ishii are new records to the Chinese insect fauna.The males of thelatter three species are deseribed for the first time in this paper. Microterys sinicus, sp. nov. The new species closly resembles M. lunatus Dalman, and the differences betweenthese two species may be shown in the following table: Holotype , allotype , paratypes 2 1: Emei (29°35′N, 103°31″E), Sichuan,V,6, 1975.Other paratypes: 2 2: Huili (26°36′N,102°12′E), Sichuan, V, 7, 1975;7: Zhaojiao (28°5′N, 102°50′E), Sichuan, V, 25, 1974; 7 7: Qiaojia (27° N,103°E), Yunnan,V,10,1974. All reared by the author from the egg chambers of Ericerus pela Chav. The typespecimens are deposited in the Department of Biology,Sichuan University, Chengdu.The larvae of this species are predaceous uoon the eggs of its host.

2 citations




Book ChapterDOI
01 Jan 1982
TL;DR: In this paper, eight solid complex compounds obtained by reactions of uranyl nitrate, uranyl chloride, and thorium nitrate with crown ethers DB18CR6, B15CR5, and 18CR6 in polar solvents were characterized by elemental analysis, melting points, and infrared spectra analysis.
Abstract: Eight solid complex compounds obtained by reactions of uranyl nitrate, uranyl chloride, and thorium nitrate with crown ethers DB18CR6, B15CR5, and 18CR6 in polar solvents were characterized by elemental analysis, melting points, and infrared spectra analysis. Four complexes had chemical compositions which differed from those reported in the literature. It was not possible to obtain IR spectra of the crown ethers, or with the nitrate complexes with the KBr-pressed-disk technique, although the Nujol-Mull technique was adequate. A shift of the characteristic frequencies in the IR spectra of the complex compounds might be observed as crown ethers are converted to complexes.

Journal ArticleDOI
TL;DR: In this paper, a new method has been introduced which combines roulette and splitting with statistical estimation for accelerating convergence in Monte Carlo simulation, and a trial calculation of the sputtering yield produced by T ions vertically incident on Ni has been performed using the above method and the result of the calculation has been compared with that of others.

Journal ArticleDOI
TL;DR: In complete separable metric space random fixed point theorems have been discussed by Bharucha-Reid[1,2], Hans[3], Itoh[4,5] and the author's papers as mentioned in this paper.
Abstract: Random fixed point theorems are of fundamental importance in probabilistic functional analysis. In complete separable metric space random fixed point theorems have been discussed by Bharucha-Reid[1,2], Hans[3], Itoh[4,5] and the author's papers [15–20].