图的积的广义燃烧数

图的燃烧数是指在图的燃烧过程中所需要的最少时间数.2021年,李银奎等人提出图的广义燃烧数.图G的广义燃烧数br(G)是指图的广义燃烧过程需要的最少时间数.本文解决了完全k叉树的广义燃烧数的一般性结果,并部分解决了字典积和笛卡尔积的广义燃烧数问题.     

初中化学《燃烧和灭火》课题的教学研究

一、基础知识思维导图 燃烧的条件、灭火的原理和方法以及易燃物和易爆物的安全知识是本节重要内容.根据学生对燃烧现象的了解,通过实验探究、实验分析可得出燃烧的条件有三：可燃物;可燃物与氧气接触;温度达到可燃物的着火点.破坏燃烧的条件,使燃烧不能继续进行,这就是灭火的原理.根据灭火原理可确定灭火的方法.通过安全知识的学习,增强安全意识中考中常以选择题、填空题、实验题的形式出现二、重点难点突破（一）燃烧1.燃烧一定有氧气参加吗燃烧的概念有狭义和广义两种.我们通常所说的燃烧是狭义的燃烧,     

生物质与煤共燃特性的研究

利用TG-DTG（热重-微分热重）热分析技术研究了生物质、煤及其混合物燃烧的燃烧性质.考察了它们各自的着火温度、最大失重速度和燃尽温度等燃烧特征参数,计算了着火性能指数和综合燃烧特性指数.结果表明,生物质的燃烧分为250～350℃之间和350～450℃之间两个阶段;生物质的燃烧性能相近,结构相似;生物质的综合燃烧特性指数明显高于煤的综合燃烧特性;生物质与煤样混燃可有效地降低着火温度,改善煤样的燃烧性能.     

警惕:有机物的不完全燃烧

剖析燃烧产物,改善燃烧条件,消除环境污染,已成为有机物燃烧命题的要点,就其命题形式,归纳如下,供大家参考. 一、燃烧条件的选择含碳物质的不完全燃烧是导致空气中一氧化碳污染的主要原因,通过分析燃烧条件,改善燃烧环境,使有机物充分燃烧,以减少CO的产生.此类问题的解题方法,通常是通过写出有机物燃烧的化学方程式,比较不同有机物的耗氧量,从而确定反应物的条件.     

有机材料的燃烧与阻燃

分析阐述了燃烧发生的原因和燃烧循环过程中的化学反应,探讨了阻止燃烧循环的基本途径.简述了阻燃剂的基本分类.     

燃烧的反应机制

燃烧看似简单,却是极其复杂的化学反应.燃烧进程并非简单地服从质量作用定律.本文阐述氢气、一氧化碳以及烃类的燃烧实质,揭示了自由原子H、O以及根OH是燃烧反应的活化中心是链式反应得以进行的本质所在.     

秸秆着火及燃烧特性的实验研究

采用非等温热重分析法对玉米秆、小麦秆及稻秆着火、燃烧燃烬特性进行实验研究,提出了秸秆的挥发分着火、燃烧燃烬特性的特性参数,并测算了反映燃烧性能的燃烧特性指数和挥发分特性指数.结果表明,玉米秆和小麦秆的着火温度随升温速度的增大而减小,燃烧特性指数随升温速度的增加而增加.稻秆的着火温度、燃烧特性指数随升温速度的增加而增加.     

基于DCS的煤气燃烧锅炉控制系统的设计

针对煤气燃烧锅炉存在燃烧不稳定、热效率低、自动化程度不高等问题,本文设计了一种基于分布式煤气燃烧锅炉控制系统,对燃烧锅炉现场进行数据采集和远程监控,实现锅炉的液位控制、燃烧控制及监控系统的远程控制.该系统采用MACSV组态软件进行锅炉控制,软件编程层次清楚,现场调试方便,利用其强大的通讯功能可组成各种分布式监控管理系统.     

富氧燃烧实验台及燃烧特性研究

富氧燃烧是节能、环保的一项重要技术.通过石油液化气在实验台中富氧燃烧的热工试验研究,通过控制助燃空气的含氧浓度来改变燃烧特性和火焰形状、温度,确保合理燃烧.助燃空气中的含氧浓度控制在24%～28%范围内,燃烧的技术性、经济性能较佳.根据燃烧火焰的流动特性和局部助燃富氧空气流动特性确定相关参数,能够得到较好的燃烧效果,较高的锅炉热工效率.采用该方法进行局部增氧助燃烧更为经济、实用.     

烛光点点大智慧——例析有关蜡烛燃烧的中考试题

蜡烛燃烧是生活中常见的化学现象,在现行九年级上教版化学教材中到处都闪烁着蜡烛燃烧的光芒.一支小小的蜡烛燃烧蕴藏着许多深刻的化学道理,有关蜡烛燃烧的探究实验已成为中考命题的热点.一、燃烧条件与灭火原理例1同学在研究物质燃烧的条件时,做了如右图所示的实验:把一条粗金属丝绕成线圈,罩在一支蜡烛的火焰上,火焰很快就熄灭了.对这一实验的说法不正确的是A.金属丝有良好的导热性B.可燃物的温度降到着火点以下C.若预先将金属丝加热,蜡烛就不会很快熄灭     

Voices Along the Journey: Midwives' Perceptions of Implementing the CenteringPregnancy Model of Prenatal Care

The purpose of this study was to describe the reported perceptions of six midwife participants at different stages of their engagement in a multiphase process of adopting a new model of prenatal care. Midwives were interviewed at five different stages during the process of implementing CenteringPregnancy, a model of group prenatal care. The research methodology used in this study was phenomenology. The conceptual framework for exploring the participants' perceptions was based on the Institute for Healthcare Improvement's patient-centered model and on the International Institute for Restorative Practices' empowerment model. The five themes that emerged from the midwives' experiences mirrored the stages of change health education model. Suggestions for the implementation and sustainability of the CenteringPregnancy model of care are provided based on the five themes that emerged from this study's findings.     

风暴潮极值状态下珠江河网白坭水道内的不稳定流动

利用1999年洪季和9316号台风风暴潮的实测资料,通过ECOMSED数学模型对珠江河网广州区域进行数值模拟计算.计算结果显示,在99年洪季时,河网内白坭水道流动为通常的往复流动;但在风暴潮极值状态下,由于受极值流速及地形的影响,流动在白坭水道中弯曲扭摆,呈现出流动不稳定现象.     

Prediction of the science inquiry skill of seventeen-year-olds: A test of the model of educational productivity

The study was designed to investigate the influence of student characteristics and classroom characteristics on students' inquiry skill. The sample consisted of a national stratified random sample of 1955 17-year-olds who were assessed as part of the 1981-1982 national assessment in science. The dependent variable was a 17-item measure of students' inquiry skill. The independent variables were selected from the available data using the Model of Educational Productivity as a guide in the selection of the variables. The first purpose of the study was to test the effectiveness of the Model of Educational Productivity for predicting the inquiry skill of 17-year-olds. The results of this study indicate that this model was capable of accounting for between 24 and 32% of the variance in inquiry skill for the general population of 17-year-olds. More specifically, students' reporting of their general ability alone accounted for between 17 and 22% of the variance. The second question posed by this study asked whether the prediction of inquiry skill differed for males and females. While there was some difference in the contribution of the minor predictors, there was very little difference in the prediction of inquiry skill for males and females using the Model of Education Productivity. The third question posed by this study asked whether the prediction of inquiry skill differed for white and nonwhite students. For nonwhite students, the Model of Educational Productivity accounted for only 18% of the variance in science inquiry skill. Thus, it would appear that there is a great deal that is not known about the factors that contribute to the science inquiry skill of nonwhite students.     

清末新政与日本的亚洲主义

清末新政是一场王朝自救运动，历时十年。日本参与并引导了这场改革，期间中日关系相对缓和，日本亚洲主义影响下的对华政策给这一现象带来了答案。     

论我国刑法中的关系犯及其特征——以利用影响力受贿罪为视角

我国刑法增设了利用影响力交易罪,其在犯罪主体上首次确立了关系犯,在行为方式上将斡旋受贿行为无限延伸;本罪主体与请托人、与被利用的国家工作人员之间存在不同的共同犯罪形态;本罪行为的性质是斡旋受贿,为保持刑法分则第八章同类客体的统一性,需要对关系犯的自然身份给予法定化,并看作是法定身份的投射。     

Imagining a future,living in the present and remembering the past

The remit for this short piece was to identify themes emerging from the articles in this edition by Julie McLeod, Duncan Waite and Eugenie Samier, to consider how these themes reflect on the current field, and to identify their ongoing relevance. Additionally, I was asked to consider the current challenges that the field is facing and what this means for research and journals such as this one. My short response is that our research has to matter. It has to matter to us as individuals so that what we do is worthwhile; it has to matter that we can provide rigorous research that is reliable so that it can inform policy makers and administrators; and it has to provide teachers and students with a greater understanding of why they are doing what they are being asked to do.     

Measuring the impact of a pilot Geospatial Technology Apprenticeship Program for the Department of Labor

The Geospatial Technology Apprenticeship Program (GTAP) pilot was designed as a replicable and sustainable program to enhance workforce skills in geospatial technologies to best leverage a $30 billion market potential. The purpose of evaluating GTAP was to ensure that investment in this high‐growth industry was adding value. Findings from this evaluation showed that investments in geospatial technology competency development have the potential for high‐systemic payoffs and sustained economic growth.     

Analysis and assessment of the Jordan National Test for Controlling the Quality of Science Instruction (NTCQSI): a Rasch measurement perspective

The purpose of this study was to analyze and assess the Jordan National Test for Controlling the Quality of Science Instruction (NTCQSI) from the perspective provided by Rasch measurement. The test was administered on a stratified random sample that consisted of 41,556 tenth graders from all over Jordan. The test results were saved in a data bank. A random sample of 150 participants' records was selected from this data bank. To address the purpose of this study, a series of analyses were conducted. WINSTEPS and RUMM programs were used for the analysis. The procedures that were used in this paper might be used by worldwide testing agencies to clarify or outline how Rasch measurement may be used to obtain evidence for the validity of inferences of tests data.     

儿童孤独感与同伴关系的相关研究

孤独感是一种消极、弥散性的心理状态,儿童长期处于此状态会导致适应不良.同伴关系在本文采用同伴提名法和问卷调查法,对4-5年级共258名儿重进行了研究.结果表明:儿童的孤独感在年级和性别上的差异不显著;受欢迎组儿童的孤独感显著低于被拒绝组儿童.