Prediction of formation enthalpies for Al2X-type intermetallics using back-propagation neural network

A back-propagation artificial neural network (ANN) was established to predict the formation enthalpies of Al₂X-type intermetallics as a function of some physical parameters. These physical parameters include the electronegativity difference, the electron density difference, the atomic size difference, and the electron–atom ratio (e/a). The values calculated by the ANN method agree with experiments well to typically within 10%, indicating that the well-trained back-propagation (BP) neural network is feasible, and can precisely predict the formation enthalpies of Al₂X-type intermetallics. The method comparison based on the predicted formation enthalpies suggests that our ANN method is superior to Miedema's model. Some trends of formation enthalpies for Al₂X-type intermetallics were also observed from the ANN.     

Nonparametric inference based on panel count data

Panel count data usually refer to data arising from studies on recurrent events in which the subjects under study are followed or observed only periodically rather than continuously. In such situations, an objective of interest is about the occurrence of some events that can occur multiple times or repeatedly and the studies resulting in this type of information are often referred to as event history studies. There are many fields such as medical studies, reliability experiments and social sciences wherein panel count data are encountered commonly. This article reviews basic concepts about panel count data, some common issues and questions of interest regarding them as well as the corresponding statistical procedures that are suitable for their analysis. In particular, we will discuss an estimation of the mean function of the underlying counting process characterizing the occurrence of the events, comparison of several processes and analysis of multiple state panel count data. Some discussion is also presented of situations involving dependent or informative observation processes.     

On the equivalence of linear codes

Certain equivalent conditions are given for the equivalence of linear codes using the properties of the relative subcodes derived from the relative generalized Hamming weight.     

核电用钢的开发与展望

阐述了我国核电发展的现状及特点,重点介绍了鞍钢在核电用钢开发方面现有装备情况及取得的业绩,同时对我国钢铁企业未来核电用钢的研发方向进行了展望。     

Schiff碱-双（呋喃甲醛）缩联苯胺的合成与光谱研究

Schiff碱在材料、催化剂和分析化学方面等的研究都有了很大进展,也越来越受到重视。文章以呋喃甲醛和联苯胺为起始原料,在无水甲醇的溶剂中合成了一种新的Schiff碱,收率为85.0%。反应的最佳条件是呋喃甲醛与联苯胺的比例为3∶1,反应时间为1h,反应温度为30℃。这种新的Schiff碱结构且通过了IR和UV光谱测定。     

Multi-displacement continuum model for discrete systems

A first-order multi-displacement microstructure continuum model is introduced to represent a discrete diatomic lattice system. This model is developed based on a two-term Taylor series expansion of the local displacement of the lattice. It is found that the multi-displacement continuum model obtained by keeping two terms in the Taylor series yields, in general, a better representation of the lattice system than the effective modulus model. However, this microstructure continuum model cannot characterize the negative group velocity of an optical mode of harmonic wave motion in the diatomic lattice. To capture the negative group velocity, a higher-order multi-displacement continuum model is necessary.     

流舍矿防治老窑水的做法与效果

从管理与技术方面介绍了流舍矿老窑水的防治措施及其取得的效果.     

基于Multisim的控制系统串联校正分析

利用NI Multisim10仿真软件对控制系统串联校正进行了AC频率分析与瞬态分析,阐述了利用该软件进行控制系统仿真的具体方法和一般过程,给出了仿真波形并进行了相关分析。界面直观,操作方便,可以大大降低开发成本,提高开发效率,对于控制系统开发和教学具有一定的指导意义。