太阳能空间斯特林热机性能的优化分析

建立太阳能驱动的空间斯特林热机的循环模型，应用有限时间热力学理论和太阳能集热器的辐射损失模型，研究受热阻和回热损失影响的太阳能斯特林热机循环性能，导出空间热机效率的基本优化关系，确定太阳能集热器的最佳工作温度和效率界限，讨论各种不可逆性对空间热机性能的影响，所得结论可为太阳能空间斯特林热机的优化设计提供新的理论指导。     

数字内容产品版权保护的演化博弈分析

[目的/意义]基于版权保护的演化博弈分析，有助于探究数字内容产品的原创主体对仿冒行为是否具有容忍度，以及不同仿冒水平下实施版权保护的策略选择，对规范数字内容产品市场主体行为具有一定指导意义。[方法/过程]首先借助演化博弈模型，分析原创主体与仿冒主体的利益演化过程，探究版权保护下原创主体对仿冒水平的容忍行为；然后通过细化博弈双方的利润函数模型，探究原创主体容忍度水平的决定因素。[结果/结论]原创主体对较小的仿冒水平存在一定的容忍度，对较高的仿冒水平零容忍。最大仿冒水平容忍度由仿冒交叉收益系数、收益模型常系数、产品研发成本系数和原创主体的产品研发努力水平倍数4个因素共同决定。     

烧结动力系统节能减排措施和应用

烧结工序能耗约占钢铁生产总能耗的8．3%,仅次于炼铁。文章介绍本钢炼铁厂一烧结车间针对本车间烧结生产消耗大量水、汽等能源,同时在烧结生产过程中向空气中排放大量热能的特点,采用工业循环冷却水,回收余热再利用等措施,以达到节能减排的目的。     

Building an understanding of heat transfer concepts in undergraduate chemical engineering courses

Understanding the distinctions among heat, energy and temperature can be difficult for students at all levels of instruction, including those in engineering. Misconceptions about heat transfer have been found to persist, even after students successfully complete relevant coursework. New instructional methods are needed to address these misconceptions. This pilot study examined whether researcher-developed and inquiry-based activities could increase conceptual understanding of heat transfer and alter common misconceptions. Twenty-two undergraduate chemical engineering students were assessed before and after instruction with inquiry-based activities using a ten-item concept inventory. Concept inventory questions were developed to assess students＇ performance on questions closely related to the inquiry-based activities and questions applying concepts in new contexts. Participants significantly improved their overall scores from pre-test to post-test. An examination of performance on individual items revealed significant improvement on half of those questions closely related to the instructional activities and half of those applying concepts in new but related contexts. Results are examined in light of the assessment and inquiry activities that were used, as well as the difficulty of the concepts. Educational implications and suggestions for future research are discussed.     

传热学的研究性实验教学

研究性实验教学是创新教育的重要内容,作者把创新性思维能力的培养定位于以方法论的培养为重点的教学实践,把创新思维能力的培养过程划分为3个阶段,实验教学体系也划分为基础理论的验证、演示实验教学,综合性技术实验教学和研究性自我设计型的实验教学3项内容,并讨论了推进研究性实验教学的3点看法,结合传热学给出了两个研究性教学实验设计的例子。     

油冷柴油机及其余热回收系统

本文介绍一种可以节约燃油的方法。该方法利用油冷却船用柴油机的气缸盖、气缸套及其它部件,并使气缸盖出口处冷却温度在大气压力下为100℃或更高。由于提高了冷却介质的出口温度,减少了热损失,增加余热回收,从而取得节油效果。     

Creating Respectful Classroom Environments

Creating respectful classroom environments Respect is a critical variable in education. It is critical to each individual child in the classroom environment as well as to the teaching and learning that takes place in the classroom. Children learn by example. Where do they get their examples? This article explores the parameters of teaching and encouraging respect in classrooms for young children. Emphasis is placed on the creation of respectful classroom environments taught by teachers who have themselves been prepared to nurture this kind of environment.     

火电厂锅炉高排烟温度剖析及处理对策研究

排烟热损失是目前火电厂节能降耗的重心之一,高排烟温度不仅大大增加了排烟热损失,降低了锅炉效率,增加了尾部烟道再燃烧的风险,同时对脱硫系统的正常运行也有一定的影响。文章通过对可能影响排烟温度的相关因素进行逐一分析研究,探讨从机组运行调整及设备改造的角度在条件允许的前提下尽可能降低排烟温度水平的可能。     

相变潜热随温度的变化及其对物质的蒸气压方程的影响

当物质发生一级相变时，相变潜热是温度的函数．考虑与凝聚相达到平衡的饱和蒸气，当相变潜热随温度发生变化时，求得物质的蒸气压方程．     

排名前10的与预防运动和体育活动猝死相关的关键问题

参加有组织的体育运动和休闲活动存在发生严重伤病甚至死亡的内在风险。虽然造成体育运动或体育活动中猝死的原因有很多,但运动医学和循证标准治疗方面的进展已使临床医生得以更有效地预防、发现和治疗可能致死的伤患。随着研究与技术不断发展进步,当前的治疗标准正在不断发展以更好地改善患者的治疗效果。本文提出了10个与运动和体育活动中猝死的主要原因及其治疗手段有关的关键问题,未来开展的研究将提高运动员和休闲运动爱好者参与运动的安全度。当前证据表明,如采取正确的预防策略或最佳治疗方案,绝大多数的死亡案例是可以避免的。