光缆拉伸应变分布测量的新方法：布里渊光纤时域分析技术

通信光缆拉伸应变分布测量对于保证光纤通信线路的长期可靠性具有十分重要的意义。文章论述了布里渊光纤时域分析技术的背景、现状、描述了该技术的基本原理，存在的问题以及目前研究的最新进展。     

测量液体粘滞系数实验的研究

本文利用液体的绝对速度理论得到液体的粘滞系数随温度变化的关系式，在不同的温度下测得液体的粘滞系数，找出液体的粘滞系数随温度变化的数学表达式。     

P－正则半群的双序集

本文刻划了双序集Ｅ为某Ｐ－正则半群的幂等元双序集的充要条件．所得定理不仅推广了Ｄ．Ｅａｓｄｏｗｎ关于带的双序集的结论，而且导出了正则＊－半群的幂等元双序集的一个刻划．进而还对Ｐ－正则半群的若干特殊情形及向非正则半群的推广进行了讨论．     

On computing the entropy of the Henon attractor

In a recent article D. Ruelle [inLecture Notes in Physics, No. 80 (Springer, Berlin, 1978)] has conjectured that for the Hénon attractor its measure theoretic entropy should be equal to its characteristic exponent. This result is known to be true for systems which satisfy Smale's Axiom A. In this article we report the results of our computations which suggest that Ruelle's conjecture may be true for the Hénon attractor. Further, in our study we are confronted with fundamental questions which suggest that certain existence theorems from ergodic theory are not sufficient from a computational point of view.     

Electromigration effects in aluminum alloy metallization

An investigation of electromigration-induced failure in aluminum alloy films, with the major emphasis on aluminum-copper-silicon, was conducted. Flash evaporation was utilized for alloy deposition and yielded aluminum-copper films having electromigration resistance comparable to that of such films prepared by other techniques. Results for aluminum-copper-silicon and aluminum-copper were similar indicating the passive role of silicon in the presence of copper. Additions of four weight percent copper resulted in near-optimum electromigration resistance. In addition, hot-substrate deposition was beneficial in attaining greater lifetime. For films deposited on unheated substrates, or having lower copper contents, heat treatment seriously degraded electromigration resistance. Heat treatment effects were considered to be a consequence of copper redistribution. Lifetime decrease at large copper contents and possible saturation at large thicknesses were interpreted in terms of clustering of CuAl₂ precipitates. The superior reliability of copper-alloyed metallization when compared with aluminum or aluminum-silicon was clearly demonstrated. Lifetime improvement could be accounted for by the increased activation energy for the failure process in the aluminum-copper alloys.     

The excess volumes of tetrahydronaphthalene inn-alkanes at 10 and 25°C

The excess volume of mixing tetrahydronaphthalene with n-pentane, n-hexane, n-heptane, n-octane, n-dodecane and n-hexadecane have been measured over the whole composition range at two temperatures. The results are compared to the excess volume of mixing bicyclohexyl with the same solvents.     

X-ray determination of the mean amplitudes of vibration and debye temperatures of some rare earth monochalcogenides

The x-ray diffraction intensities of Bragg reflections have been measured at room temperature for thulium selenide, samarium sulphide, samarium selenide and samarium telluride. On the basis of a common amplitude approximation, the Debye-Waller factor, the mean amplitude of vibration and the Debye temperature have been evaluated. The values of the Debye temperatures and mean amplitudes of vibration are 176±16°K, 0·185 ± 0·017 Å (TmSe), 155 ± 7°K, 0·244 ± 0·012 Å (SmS), 153 ± 14°K, 0·221 ± 0·020 Å (SmSe) and 151 ± 20°K, 0·204 ± 0·027 Å (SmTe).     

Triangular lattice Potts models

In this paper we study the 3-state Potts model on the triangular lattice which has two- and three-site interactions. Using a Peierls argument we obtain a rigorous bound on the transition temperature, thereby disproving a conjecture on the location of its critical point. Low-temperature series are generated and analyzed for three particular choices of the coupling constants; a phase diagram is then drawn on the basis of these considerations. Our analysis indicates that the antiferromagnetic transition and the transition along the coexistence line are of first order, implying the existence of a multicritical point in the ferromagnetic region. Relation of the triangularq-state Potts model with other lattice-statistical problems is also discussed. In particular, an Ashkin-Teller model and the hard-hexagon lattice gas solved by Baxter emerge as special cases in appropriate limits.Supported in part by NSF grant No. DMR 78-18808.     

Stationary phases for gas chromatography; chemical stability of polysiloxanes

A number of polysiloxanes have been shown to be sensitive to acids when dissolved in chloroform. At 26O°C polysiloxanes were found to degrade under the influence of several compounds used or produced during the preparation of glass capillary columns.