Global attractivity of a higher-order nonlinear difference equation

The main goal of this paper is to investigate the locally asymptotically stable, period-two solutions, invariant intervals and global attractivity of all negative solutions of the nonlinear difference equation

     

Predicting the strain hardening characteristics of ageing alloys under combined loading

The paper examines the effect of the initial structure and prestrain on the yield stress of a number of ageing steels and alloys under combined loading in the cases of like and opposite directions of preloading and reloading. The parameters of yield loci are calculated for the case of combined two-axial tension. Their predicted dependence on temperature, ageing time, and prestrain is experimentally checked. As they increase, strain hardening changes from isotropic to kinematic and then to mixed __________ Translated from Prikladnaya Mekhanika, Vol. 43, No. 6, pp. 116–125, June 2007.     

海关走私监管的演化博弈分析

利用演化博弈的方法对海关缉私部门和走私商之间相互作用时的策略,进行了分析。结果表明：当企业进行走私活动的收益大于不走私的收益、海关缉私部门对走私企业处罚力度过轻或对缉私检查的成本过高时,走私必然发生。要确保走私的发生率降低,就必须对进行走私的企业进行严惩,降低其的预期收益。同时,要加强缉私队伍建设。     

电势-pH图在判断高锰酸钾反应产物中的应用

针对无机化学实验的性质实验模块中,关于溶液酸碱度对高锰酸钾与亚硫酸钠间氧化还原反应产物的影响,以及反应放置一段时间后化学现象发生变化等问题,利用能斯特方程推导出相关电对的电极电势随pH变化表达式,通过电势-pH图讨论了Mn体系相关物质在水中的热力学稳定性和存在形式,讨论了在不同酸度下KMnO₄作为氧化剂,与Na₂SO₃反应生成不同产物的原因,并从理论上探讨了放置一段时间后,在特定的酸碱性条件下因某种反应物过量等因素而观察到产物继续会转化成MnO₂、Mn(OH)₂等的可能性。     

A note on characterizations of multivariate stable distributions

Several characterizations of multivariate stable distributions together with a characterization of multivariate normal distributions and multivariate stable distributions with Cauchy marginals are given. These are related to some standard characterizations of marcinkiewicz.Research supported, in part, by the Air Force Office of Scientific Research under Contract AFOSR 84-0113. Reproduction in whole or part is permitted for any purpose of the United States Government.     

Maximal line subbundles of stable bundles of rank 2 over an algebraic curve

Let E be a vector bundle of rank 2 over an algebraic curve X of genus g ≥ 2. In this paper, we prove that E is determined by its maximal line subbundles if it is general. By restudying the results of Lange and Narasimhan which relates the maximal line subbundles with the secant varieties of X, we observe that the proof can be reduced to proving some cohomological conditions satisfied by the maximal line subbundles. By noting the similarity between these conditions and the notion of very stable bundles, we get the result for the case when E has Segre invariant s(E) = g. Also by using the elementary transformation, we have the result for the case s(E) = g−1. I. Choe and J. Choy were supported by KOSEF (R01-2003-000-11634-0) and S. Park was supported by Korea Research Foundation Grant funded by Korea Government(MOEHRD, Basic Research Promotion Fund) (KRF-2005-070-C00005)     

Cesium-Fluoride-Promoted Synthesis of Stable Organocesium Reagents and Their Ambident Reactivities with Arynes

Described are the diverse reactivities of novel, stable, ambident thio-organocesium reagents (bearing electron withdrawing groups) against benzynes. Reactions at reflux temperature predominantly led to the generation of various functionalized stable sulfonium ylides and at 40 °C the same reaction underwent direct c-arylation. Furthermore, lack of internal hydrogen on the cesium reagent helped to produce different ortho-bifunctional arynes in both the reactions. Interestingly, depending on the reactivities of substrates, the one-pot tri-component procedure generated either ylides or σ-bond insertion products.     

Increased thermostability of non-polar wall-coated open tubular columns

A method of deactivating the inner surface of glass capillary columns is described, which can be used at 350°C without detoriation. A non-polar liquid phase was prepared from a commercially available liquid phase which, when coated on a glass surface, can withstand temperatures of 325°C for isothermal analysis and 350°C for temperature-programmed analysis. After deactivation, the column was coated using the static coating method. Then it was conditioned, tested and kept for 48 hours at 35O°C before being used for the analysis of a mixture of chlorinated pesticides.