长齿条的加工工艺分析

长齿条由于尺寸太长而无法在通用设备上加工,改装有车齿装置的C630-Ⅱ型车床可同时加工几十根齿条;X63型铣床采用专用铣头后也可加工,两者有不同的优缺点,决定了不同的使用场合.     

论器具信息技术

器具信息技术是信息技术中不同于身体信息技术的另一个重要种类,信息的载入设备、载体和媒介是考察器具信息技术的三个重要侧面,它们集合形成了不同时代的信息装置范式,信息装置范式的演变标志着人类文明形态的演变。器具信息技术具有作为人造物、折射人的本质以及指向信息等三个总体特征。     

Can we predict device use? An investigation into mobile device use in surveys

In this study, we investigate whether mobile device use in surveys can be predicted. We aim to identify possible motives for device use and build a model by drawing on theory from technology acceptance research and survey research. We then test this model with a Structural Equation Modeling approach using data of seven waves of the GESIS panel. We test whether our theoretical model fits the data by focusing on measures of fit, and by studying the standardized effects of the model. Results reveal that intention to use a particular device can predict actual use quite well. Ease of smartphone use is the most meaningful variable: if people use a smartphone for specific tasks, their intention to use a smartphone for survey completion is also more likely. In conclusion, investing in ease of use of mobile survey completion could encourage respondents to use mobile devices. This can foremost be established by building well-designed surveys for mobile devices.     

Impact of COVID-19 on breastfeeding intention and behaviour among postpartum women in five countries

BackgroundStudies regarding the impact of COVID-19 on breastfeeding have mostly used single- country samples or a qualitative design.AimThe objective of this study was to examine breastfeeding intention during pregnancy and breastfeeding behaviour among postpartum women in five countries during the COVID-19 pandemic and the associated factors.MethodsAn online questionnaire survey was conducted in Thailand, the United Kingdom, South Korea, Taiwan, and Brazil from July through November 2021. The study participants included 3253 mothers within six months of birth.FindingsAbout 90% of participants intended to breastfeed during pregnancy and 85.7% reported breastfeeding in the past 24 h. More than half reported their breastfeeding duration being as planned or longer despite COVID-19. Multivariate logistic regression models showed that being multiparous, ever tested COVID-19 positive, and having positive breastfeeding beliefs were associated with increased odds for intention to breastfeed during pregnancy. Lower maternal educational level, being primiparous, ever tested COVID-19 positive, and experiencing food insecurity were associated with decreased odds for breastfeeding duration being as planned or longer. Vaginal birth, currently working or on maternity leave, breastfeeding beliefs, breastfeeding support from spouse/partner/friend/relative, online support groups, and in-person or telephone contact with healthcare professionals were associated with increased odds for breastfeeding duration being as planned or longer.ConclusionBreastfeeding intention and behaviour remained high during the COVID-19 pandemic. Online support groups and telephone contact with health professionals were effective during the pandemic.     

1300V/20A绝缘栅双极晶体管IGBT

基于理论概括与实验研究,已经在N~-/N~+/P~+外延基片上获得了1300V/20A高性能IGBT;并进而指出了实现该器件互相关联的关键技术。它们分别是:优质厚层低缺陷密度异型硅外延材料的工艺制备,器件纵横向几何结构及工作参数的准确量化,和通过叠加组合形成的复合高压终端结构。     

利用情绪生成心理机制培养学生的自我效能感

本文从情绪生成心理机制的角度论述了学生自我效能感的培养 ,着重强调了如何利用需要、客体与预期的关系、观察性学习、表情训练、认知和评价、兴趣等因素来培养学生的自我效能感 ,并指出自我效能感培养的最终目标是使学生能将之内化为自身性格并能有意识地在该方面进行自我教育。     

绕射辐射振荡器研究

介绍了“绕射辐射振荡器研究”的成果，简述了理论分析、三维计算及设计方法；给出了实验结果并对有关问题进行了讨论。实验管测试的主要参量为：在工作电压２４００～４０００Ｖ；频率范围ｆ＝８４～１０４ＧＨｚ内测得高频振荡，最大输出功率达２００ｍｗ。频率范围ｆ＝６０～８２ＧＨｚ；最大输出功率达１．３Ｗ。同时介绍了这种器件在科学技术中的应用。     

电子实验装置的抗干扰技术

通过分析电子装置产生干扰的原因,对线路板、电源、系统结构、控制信号电缆和传输信号线路等环节进行了各种抗电磁干扰设计,提高整个系统的抗干扰能力。     

"建筑环境与设备工程"专业设置的优化

文章阐述了建筑环境与设备工程专业教学改革的目的和重要意义 ,通过分析本校的实际情况 ,提出了该专业课程的优化设置 ,注重素质教育和能力培养 ,并反映铁路特色 ,使培养的毕业生能够成为德智体全面发展的高素质人才。     

计算机辅助英语学习

外语教学的远期、最终目标是逐渐培养学生目的语的交际能力。然而 ,对于一般的外语教师来说 ,在常规教室里面是很难具体操作的。随着 2 0世纪信息时代的出现 ,计算机辅助英语教学为外语教学提供了更为先进的媒介和空间。短短几十年时间计算机辅助英语教学发展如此迅速 ,必然有其独特的优势和强大的潜力。本文就 CAL L的历史、发展及现状进行了介绍 ,并结合中国传统教学隐藏的弊端以及 Krashen二语习得机制理论进行深入的探讨。同时 ,本文也对 CAL L的优势和前景进行了系统深入的分析。