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Characteristics of R22 and its new alternative refrigerant R200 flowing through adiabatic capillary tubes are investigated based on the homogeneous model. Extensive flow variables along tube length such as pressure, temperature, viscosity, velocity. Reynolds number, friction factor and vapor quality etc are compared between the two fluids under the same operating condition. Two cases are considered, namely, either the same tube length or the same mass flow rate as inlet condition. The results show that the mass flow rate in the capillary tube of R290 is 40% lower than that of R22 due to the differences of physical properties between the two fluids. Further. a parametric analysis is performed and it appears that effects of geometric and thermodynamic parameters on mass flow rate of R290 are weaker than that of R22. When the condensing temperature is increased from 40℃ to 50℃ C. the mass flow rate for R22 is increased by 16%. while the increasing rate for R290 is 13%. 相似文献
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James Langston Hughes was born February 1,1902, inJoplin, Missouri. His parents divorced when he was a smallchild, and his father moved to Mexico. He was raised by hisGrandmother until he was thirteen, when he moved to Lincoln,Illinois, to live with his m… 相似文献
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受美国次贷危机的影响,我国民营企业发展受到较大影响,相当多的企业发展陷入困境,为了促使民营企业获得稳定发展,应正确应对人民币升值,向制造成本更低的国家转移生产基地,开拓新的出口市场,在精益和柔性生产领域投资,明确品牌形象,增加优势产品的产能,兼并收购,行业结盟应对挑战. 相似文献
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人格,包括情操、品行、道德、伦理、气度、胸怀等内涵.教师人格以高尚的师德、超人的才情、深厚的学养为基础,升华而成人格魅力和精神气质,通过各种途径和方式渗透、融合到教育教学活动过程中.学生的道德观、人生观、价值观、世界观的形成,除了来自书本、社会、家庭的影响之外,最直接、最具体、最[深刻的影响来自教师.从这个意义上来说,人格就是教师的一切.教师应以自己良好的人格去影响学生、塑造学生. 相似文献
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Acapillarytubeiscommonlyusedastheexpan sionandflow rate controllingdeviceinsmallrefrige ratingandair conditioningsystems.Recently,itsap plicationhasbeenextendedtolargerunitssuchasunitaryairconditionersofsizeupto35.2kWcapaci ty[1].Itssimplicity,havingnoactiveparts,lowcostandlowstartingtorqueofcompressorsarethemain reasonsforitswideuse.Despiteitssimpleconfigura tion,theflowinsideacapillarytubeisverycomplexanditsbehaviorsignificantlyinfluencestheperform anceofthewholesystem.Inthepastdecades,many… 相似文献
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2007年1月11日-13日,新疆日报在一版重要位置连续刊发长篇通讯《各族患者都是我的亲人》、《病人的微笑是对我最大的奖赏》、《他感动了新疆》,还配发了《向庄仕华学习》、《精益求精是一种品质》、《大医大爱大境界》的本报评论员文章,全面报道了武警新疆总队医院院长庄仕华33年如一日,始终牢记全心全意为人民服务宗旨,扎根边疆,无私奉献,拼搏进取,努力创建医患和谐的事迹. 相似文献
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郝红 《新校园(当代教育研究)》2018,(6)
英语是初中必修课程,也是初中重要的学科之一,现代信息技术的发展逐渐影响着初中英语教学模式。本文分析了现代信息技术对初中英语教学的重要作用,从听力、阅读、口语等三个方面探讨了如何有效地将现代信息技术引入初中英语课堂教学。 相似文献