卫星热管传热测试台的制冷与真空系统的设计   总被引：1，自引：0，他引：1  

雷新塘  徐烈  李兆慈 《实验室研究与探索》2003,22(2):102-104

介绍了能满足卫星环境要求的热管传热试验台的制冷与真空系统的设计方案，提出了一种采用液氮制冷和分子泵抽真空系统的方案。制冷系统能方便达到 60— -60℃的温度要求，并可以任意调节所需温度，且调温精度高、反映时间短。抽真空系统能满足0．1mPa的工作真空度和方便更换试样的要求，是一台简便、实用的卫星热管传热试验台。  相似文献   

A different type of charter school: in prestige charters,a rise in cachet equals a decline in access   总被引：1，自引：0，他引：1  

Elizabeth Brown  Molly Vollman Makris 《教育政策杂志》2018,33(1):85-117

This paper seeks to elucidate a specific type of charter school. While much has been written about school choice and the expanding charter school segment, a growing and important number of charter schools do not fit in to the common understanding of these schools. Distinct from many of their counterparts, prestige charter schools have the following two features: elements which foster a reputation similar to that of elite private schools and a student population demographically distinct from local public district schools – whereby the prestige charters serve a disproportionate number of advantaged families. The prestige elements include: founding by advantaged community members; parental involvement; wait lists; popularity with advantaged professionals; high test scores; and niche themes. The authors will show through two in-depth case studies that prestige charter schools work hand-in-hand with gentrification in urban neighborhoods, and result in racial and class segregation and inequality. This paper examines how these charter schools struggle when a rise in prestige coincides with a decline in access for low-income students. The authors recommend that given the current system of school choice, prestige charter schools must use tools and mechanisms to maintain demographic diversity and educational equity which is in the best interest of all children.  相似文献   

集中供热的单独用户计量问题的解决方案     

徐玉梅  袁东 《洛阳工业高等专科学校学报》2001,11(1):28-29

从计费合理管理方便的角度出发，详细介绍了室内采暖管道每户为一独立系统，各楼层之间采用并联方式的采暖系统。  相似文献   

农民收入与城镇职工收入差异比较分析     

岳冬冬 《陕西理工学院学报(社会科学版)》2006,24(4):32-35

在认识理解收入权利的基础上,分析了农民和城镇职工在收入方面的来源差别,并且从收入权利的角度对造成这种收入来源差异的原因进行了探讨分析,为制定缩小城乡收入差距的政策提供理论参考。  相似文献   

孤寂文坛上的双子星座——苏青、张爱玲比较     

袁月华 《连云港职业技术学院学报》2007,20(2):35-38

苏青、张爱玲是40年代沦陷区上海文坛上最负盛誉的女作家，她们都以周围的题材从事写作，张爱玲以小说创作擅长，而苏青以散文写作著名。她们年龄相似、性情相同，又都写女性题材，在生活圈子、爱好情趣方面也有许多相同之处，但她们以其独特的创作风格和写作技巧，在上海的特殊气氛和背景下，大红大紫一时，可视为孤寂文坛上的双子星座。  相似文献   

新感觉派都市小说叙事模式对传统小说的突破和创新   总被引：1，自引：0，他引：1  

杨少卿 《韩山师范学院学报》2003,24(2):77-80

新感觉派是中国现代文学史上第一个现代主义小说流派．该派作家借鉴了欧美现代派和日本新感觉派的艺术表现技巧，以“感觉”为艺术表现核心，采取了独特的内向化的审美视角来发掘都市人的深层心理，拓宽了小说艺术表现领域，全面突破传统小说叙事模式，创造了新的小说叙事模式，丰富了现代小说的表现技巧。  相似文献   

浅淡有关温度和内能的几个问题     

邹道阶 《湖州师范学院学报》1994,(5)

本文讨论了温度和热量这两个热学中常用的物理量,阐述了两者的关系,并联系热力学第一定律,分析了与之相关的内能、功和热量等概念,对功和热量的异同之处提出若干看法。  相似文献   

The urban and the natural in education reform: the development of Hamburg Schullandheime (rural school hostels) in the 1920s     

Christine Mayer 《History of education》2020,49(4):459-475

ABSTRACT

The desire to be close to nature and live in tune with it grew as industrialisation, urbanisation and the impact of technology became increasingly ubiquitous at the turn of the twentieth century. Throughout Europe, model schools were established in rural environments. These private reform schools could not solve the problems of public urban schools. Founded on the initiative of teachers and parents, the Schullandheim (rural school hostel) emerged as a new form bringing urban education and schooling close to nature after the First World War in Germany. Even if related pedagogic activities developed at that time in other countries there is no evidence for comparable institutions. Besides tracing the development of Schullandheime, the article shows how the school hostel idea was embedded in the contemporary educational discussion about the influence large cities had on youth and explores the educational and cultural differences within the school hostel movement through the use of visual material.  相似文献   

义乌市城区生态环境调查分析     

刘国进 《江西教育学院学报》1994,15(6):38-43

本文对义乌城区主要环境因子，整体生态环境质量作了定性、定量分析，表明目前城区总件生态环境仍在不断退化。  相似文献   

楚汉文化品牌与徐州城市文化创新发展     

沈山  吴婧  胡瑞山 《徐州师范大学学报(哲学社会科学版)》2007,33(1):99-103

楚汉文化是体现徐州城市文化品格的核心内容，其品牌内涵为“彭祖故国、刘邦故里、项羽故都”。建议徐州城市文化创新发展的基本路径是：文化资源的整理与评估-文化产品的创意与开发-城市文化品牌的培育与营销-文化产业的整合与升级-文化战略的确定与实施；可供讨论的徐州城市文化发展战略思路是：“明确一个文化品牌，启动两大文化项目，建设三条文化产业带、确定四大文化发展基地、推进五大文化产业园区（城）、扶持六大文化产业、培育七大文化市场、八大政策保障”。  相似文献