Jacobi与Gauss—Seidel迭代法求解线性方程组收敛性比较与研究

Jacobi迭代法和Gauss-Seidel迭代法是计算机求解线性方程组常用的两种迭代法,但是这两种方法对方程的收敛性要求很严,大部分方程组均不能用以求解.给出一些基本技巧:对于简单的2阶方程组,若Jacobi法与Gauss-Seidel法均发散,可交换其两行求得其解;对一般性方程,给出一个应用性较强的定理,将方程Ax=b ATAx=ATb,可以用Gauss-Seidel求得任何｜A｜≠0方程组的解.     

Family factors and parenting in Ukraine

The present study aimed to estimate the use of positive and negative parenting practices in Ukraine and explore relationships between parenting practices, intimate partner violence (IPV), alcohol use, and sociodemographics. Parents of children (N = 320) ages 9–16 from three Ukrainian regions answered questions from the Alabama Parenting Questionnaire (APQ), the Revised Conflict Tactics Scales (CTS-R), Family Adaptability and Cohesion Evaluation Scale (FACES), and the Alcohol Use Section of the Drinking and Drug History and Current Use Patterns questionnaire. Ukrainian parents who reported lower use of alcohol, balanced family functioning and lower intimate partner violence were more likely to use positive parenting and less likely to use negative parenting practices. Parents with lower education were more likely to use negative parenting practices. Furthermore, alcohol use, IPV, parent education and higher family income were significantly and indirectly related with positive and negative parenting scores. The model explained 61% of variance in the positive parenting, 67% in the negative parenting.     

Libraries and Spatial Literacy: Toward Next-Generation Education

The role of the library is to assist citizens in skills development critical to national interest and empowerment as literacy ambassadors, in general. Specifically, the work by the Federal Geographic Data Committee (1994) indicates that spatial literacy is for every citizen and not just a set of workforce specialists. Hence, the use of maps in decision making and problem solving will become fundamental to all professions, including library professionals. Thus, a spatial literacy awareness and rationale for such as standard job ability is discussed as a future librarian workforce proficiency and knowledge transfer medium.     

Childhood adversity and the risk of substance use and delinquency: The role of protective adult relationships

Youth involved in the child welfare system experience multiple early adversities that can contribute to increased risk of substance use and delinquency. Although adverse childhood experiences (ACEs) have been associated with poorer behavioral outcomes among youth, less is known about the possible protective factors that may influence the relationship between early adversity and risk-taking behavior. This study examined whether protective adult relationships moderated the link between cumulative ACEs and substance use and delinquency after controlling for demographic characteristics in child welfare-involved youth. The sample included 1054 youth, ages 11–17, from the National Survey of Child and Adolescent Well-Being II who were in the first wave of data collection. Results showed that protective adult relationships moderated the relationship between ACEs and substance use, but not for delinquency. Specifically, under lower levels of protective adult relationships, cumulative ACEs related to increased substance use among youth. Implications for child welfare practices to target youths' support systems are discussed.     

跨学科类比法在线性代数教学中的应用

针对线性代数教学的抽象与沉闷的现状,结合当前大学生的时代特性与兴趣特性,文章将以一个教学实例为对象,尝试使用跨学科类比法,并以此为突破口,试图探索生活化的＂去数学化＂的新型教学。     

宣城市30万Nm／d液化天然气项目设计简介

文章简单介绍宣城市30万Nm／d液化天然气项目的设计，并对设计中难以把握或容易出错的地方做了重点说明。     

Dialectics of design: how ideas of ‘good design’ change

This paper advances a first‐pass theory of change in the styling of objects of domestic utility. It is based on the idea that the expressive potential of design for the maker, the user and the designer exists in tension with other desirable properties of the designed artefact. Respectively these are mass availability, conformity to professionally‐defined ideas of good taste, and the demands of function and marketability. The theory is illustrated by reference to the emergence and subsequent dilution of three design movements; Arts and Crafts, Art Nouveau and certain versions of Modernism.     

一类时滞双曲型微分方程系统的振动性

建立了一类具有连续分布滞量的双曲型微分方程系统解的振动的若干充分条件 ,并对主要结果举例说明     

基于多元线性回归分析的新疆外贸出口对策研究

目前,新疆外贸正处于新旧动能转换的关键时期,培育外贸发展新动力是进入新时代外贸的必然要求,新动力的形成主要需要供给方进行动力重塑和协调发力,在出口方面通过创新驱动、结构调整、制度变革培育供给侧新动力。研究结合供给侧改革对新疆外贸出口依存度进行分析,运用Eviews对与出口相关的因素进行多元线性回归分析,得出结论:一是要素禀赋与出口呈负相关关系;二是新疆GDP对出口有显著的促进作用;三是人民币汇率变动与出口额之间表现为强相关关系;四是外商直接投资与出口较强的相关关系。最后针对多元线性回归的结果,提出相应的外贸出口增长对策。     

再论《吴医汇讲》为中国期刊的肇端

基于无限期出版的意图和具有定期或不定期连续出版的特征是期刊最根本的2个属性,提出了《吴医汇讲》第1卷单卷刊行传播和9册本、6册本、5册本、4册本分卷、分册刊行的文字证据和版本实物证据,彻底颠覆了认为其在”3个年份里2次刻成,故非连续出版物”的错误观点,再次巩固了其为中华第一刊的正确结论.