节能温度、供热气象指数及供热参数研究   总被引：2，自引：1，他引：1  

王保民  张德山  汤庆国  李迅  孔玉斌  张姝丽  杨世燕  陈正洪  胡江林  王志斌 《气象》2005,31(1):72-74

对北京市2001～2002年采暖季的室内外气象一热力试验数据进行科学分析,求出实际条件下不同环境温度、风速、辐射等气象条件下的节能温度,提出了供热气象指数及等级划分标准,推算出总供热量、供回水温度差及通过控制回水温度而知供水温度等供热参数,并已在北京市供热作业中投入应用,为实时供热调度提供了参考依据,是节能、增效、减污的基础。  相似文献   

Intersection-pavement de-icing: comprehensive review and the state of the practice     

ZhaoHui Joey Yang 《寒旱区科学》2019,11(1):1-12

Winter maintenance operations are crucial for pedestrian and motorist safety and public mobility on urban streets and highways in cold regions, especially during winter storms. This study provides a comprehensive literature review of existing deicing technologies, with emphasis on electrical resistance-heating deicing technologies for possible applications in areas with concentrated traffic, such as street intersections and crosswalks. A thorough review of existing and emerging deicing technology for snow/ice melting was conducted. The performance of various deicing methods was evaluated and the installation and operation cost of the electrical resistance-heating methods compared. Finally, current state of the practice of intersection/crosswalk winter maintenance was surveyed among state departments of transportation in North America. The intersection/crosswalk winter maintenance procedure adopted by the State of Alaska Department of Transportation and Public Facilities was described, and the annual winter maintenance and operation cost per intersection was estimated. It was found that the annual energy cost of an electrical resistance-heating method such as the carbon-fiber-tape deicing technology is about the same as the average annual maintenance and operation cost of current practice. In addition, an automatic electrical resistance-heating deicing system will bring benefits such as minimized delay time and improved safety for pedestrian and vehicular traffic in an urban application.  相似文献   

磁能和磁复杂性向日冕的传输     

汪景琇 《中国天文和天体物理学报》1995,(3)

本文讨论了从太阳光球向日冕传输磁能和磁复杂性的过程。活动日冕，作为由电磁场和粒子组成的系统，其唯一的开场表面是太阳光球。光球层等离子体的运动和磁场的相互作用，是造成磁能和磁复杂性向日冕传播的主要根源；同时，光球上的耗散过程也对日冕磁能和磁复杂性的积累有不可忽视的贡献。  相似文献   

磁拱脚点缓慢运动引起的磁场演化和日冕加热     

彭元  吴林襄 《中国天文和天体物理学报》1988,(3)

Heyvaerts和Priest最近提出了一个线性无力场演化的简化模型来定量计算磁拱脚点做缓慢的剪切运动所引起的日冕加热。由于他们在能量的计算中漏掉了一些二阶项,并且保留了导致位移无界的磁场的线性演化项,本文对他们的工作进行了修正,同时还对脚点运动引起的磁拱无力场演化进行了进一步探讨。本文主要结果如下:(1)得到的加热效率(即耗散能量在光球供给能量中所占比例)比Heyvaerts和Priest所得结果大。(2)磁拱无力场的无耗散线性演化是不可能的。(3)由磁场位形具体说明了非线性无力场发生磁力线重联的可能性,并指出最容易发生磁力线重联的高度大约为一个磁拱宽度。  相似文献   

南太平洋辐合带季节循环及与地形和非绝热加热变化的联系     

于亚鑫  管兆勇  方陆俊  孙婧超 《气象学报》2018,76(4):566-577

利用1981—2015年NCEP/NCAR月平均资料、NOAA的逐月CMAP（CPC（Climate Prediction Center）Merged Analysis of Precipitation）降水资料以及GODAS的月平均洋流资料和SODA的月平均风应力资料,定义了南太平洋辐合带（SPCZ）的关键区域,对南太平洋辐合带的季节变化特征及南太平洋辐合带的形成和维持原因进行了分析。结果表明,在南太平洋辐合带,4月存在由东西风切变型辐合带向东风辐合型辐合带转变的现象,而12月则存在相反的转换。在对流层低层,南太平洋辐合带区域的向上伸展高度和辐合在北半球冬季较其他季节明显高和强。引起南太平洋辐合带形成与维持的原因有2个方面:一是地形作用。由于地形的阻挡,造成等位涡线发生沿澳大利亚地形的绕行,利于澳大利亚地区反气旋性环流和南太平洋辐合带区域气旋性环流的形成与维持;同时,在地形和科里奥利力共同作用下,还易使暖海水在南太平洋辐合带区域汇聚,形成高海表温度区,从而加热大气,利于南太平洋辐合带的形成与维持。二是非绝热加热作用。南太平洋辐合带区域范围内的热源作用可以使其上方的大气受到加热,并产生加热强迫纬向梯度,驱动低层大气产生辐合。这些结果对深刻认识全球环流特别是南半球热带环流变化有重要意义。   相似文献   

剪切生热与花岗岩部分熔融——关于喜马拉雅地区逆冲断层与地壳热结构的分析   总被引：2，自引：0，他引：2       下载免费PDF全文

朱元清  石耀霖 《地球物理学报》1990,(4)

本文对影响喜马拉雅逆冲断层地区热结构的三种主要热源(断层的摩擦剪切热,地壳的放射性热和上地幔的传导热)的效应进行了计算分析,在计算中考虑了岩石的流变性造成的剪应力和温度的非线性关系及岩石温度到达熔点时的熔解热.结果表明,尽管地壳的放射性热和上地幔的传导热也可能引起地壳中的部分熔融,但此时熔融将从地壳底部开始发生,这与喜马拉雅地区观测到的地质现象不符;在考虑了剪切断层带的剪切热后,熔融将从断层附近开始发生,因此得到了比较符合实际地质现象的结果.  相似文献   

微波加热在岩土工程中的应用     

胡龙 《地质与勘探》2016,52(3):570-575

介绍了微波具有的特性以及微波加热原理,包括偶极极化、离子导电和界面极化三种机制。综述了微波加热技术在岩土工程领域的相关应用,例如快速测定土的含水量、处理固体废弃物、破碎岩石等,概述了该技术在融解冻土、淤泥土脱水、公路再生沥青修复技术方面的成果,并且提出微波加热技术可应用于减少有机土有机物含量、加热快速固结软土,以及微波加热研究的具体方向,期望能推动微波加热技术在岩土工程领域的推广。  相似文献   

凝结潜热释放和地表热通量对一次飑线过程的影响   总被引：2，自引：0，他引：2  

沈新勇  岳俗甲  刘佳  李小凡 《气象科学》2016,36(6):709-720

针对2013年7月4—5日一次产生大风、短时强降水强对流天气的飑线过程进行数值试验,研究了凝结潜热释放和地表热通量在中尺度对流系统的发生发展过程中的影响。结果表明:(1)凝结潜热释放对飑线系统有重要的作用,对飑线发展维持、移动及成熟阶段的垂直结构都有着一定影响。(2)当飑线系统进入成熟阶段后,小尺度的积云对流中的凝结加热作用于中高层大气,加强了高层辐散低层辐合的配置,而对流系统内垂直上升运动的加强又导致凝结加热作用更强。(3)凝结加热作用极大地促进了飑线的低层入流、高层出流的垂直结构,以及系统前方中层入流和高层出流之间形成的间接垂直反环流,促进高空动能下传的同时,使系统前方对流不稳定性增加,新的对流单体易于触发。(4)潜热释放间接增强了对流内部的冷性下沉气流,进而加强了低层的阵风锋,使得新的对流单体能在飑锋处触发,飑线以新老对流单体交替的方式向前移动。(5)在高低空急流的垂直耦合促进飑线发展的同时,成熟阶段飑线中较强的凝结加热对高低层急流有反馈作用,一定程度上增强了这种垂直耦合。(6)地表感热、潜热通量等边界层非绝热过程在对流系统的触发和发展中起到了较为重要的作用。地表热通量在白天加强了对流边界层的湍流混合作用,由此产生的特征维持到了夜间,形成了适合飑线触发的层结条件。另外,在对流形成之前,与地表潜热通量相关的边界层加湿作用为对流的爆发贮存了丰富的水汽和不稳定能量。  相似文献   

Seismic slip recorded in tourmaline fault mirrors from Elba Island (Italy)     

《Journal of Structural Geology》2016

This paper reports the first example of fault mirrors developed in an unusual protolith, consisting of tourmaline crystals with interstitial goethite. The deformation mechanisms active in the fault zone have been investigated from the outcrop to the nanoscale, aiming to identify possible traces of frictional heating at seismic slip rate, as observed for other fault mirrors in different protoliths. The investigation revealed the superposition of two main deformational stages. The first was dominated by brittle processes and produced a cataclastic/ultracataclastic principal slip zone, a few mm thick; the second was associated with seismic slip and produced a sharp discontinuity (the principal slip surface) within the cataclastic/ultracataclastic zone. The mirror-like coating, a few microns thick, occurs on the principal slip surface, and is characterized by 1) absence of interstitial goethite; 2) occurrence of truncated tourmaline crystals; 3) highly variable grain size, from 200 μm to 200 nm; 4) tourmaline close packing with interlobate grain boundaries, and 5) tourmaline random crystallographic orientation.Micro and nanostructural investigations indicate the occurrence of thermally-activated processes, involving both interstitial goethite and tourmaline. In particular, close to the principal slip surface, goethite is completely decomposed, and produced an amorphous porous material, with local topotactic recrystallization of hematite. Tourmaline clasts are typically characterized by strongly lobate boundaries, indicative of reaction and partial decomposition at grain boundaries. TEM observations revealed the occurrence of tourmaline nanograins, a few tens of nm in size, characterized by rounded shape and fading amorphous boundaries, that cannot be obtained by brittle processes. Lastly, the peculiar interlobate microstructure of the mirror surface is interpreted as the result of grain boundary recrystallization processes taking place by deformation at high-T conditions. Our results show that tourmaline fault mirrors recorded localized high-T processes triggered by frictional heating and can be therefore considered as reliable traces of ancient earthquakes.  相似文献   

Diagnosis of the forcing of inertial-gravity waves in a severe convection system     

Lingkun Ran  Changsheng Chen 《大气科学进展》2016,33(11):1271-1284

The non-hydrostatic wave equation set in Cartesian coordinates is rearranged to gain insight into wave generation in a mesoscale severe convection system. The wave equation is characterized by a wave operator on the lhs, and forcing involving three terms—linear and nonlinear terms, and diabatic heating—on the rhs. The equation was applied to a case of severe convection that occurred in East China. The calculation with simulation data showed that the diabatic forcing and linear and nonlinear forcing presented large magnitude at different altitudes in the severe convection region. Further analysis revealed the diabatic forcing due to condensational latent heating had an important influence on the generation of gravity waves in the middle and lower levels. The linear forcing resulting from the Laplacian of potential-temperature linear forcing was dominant in the middle and upper levels. The nonlinear forcing was determined by the Laplacian of potential-temperature nonlinear forcing. Therefore, the forcing of gravity waves was closely associated with the thermodynamic processes in the severe convection case. The reason may be that, besides the vertical component of pressure gradient force, the vertical oscillation of atmospheric particles was dominated by the buoyancy for inertial gravity waves. The latent heating and potential-temperature linear and nonlinear forcing played an important role in the buoyancy tendency. Consequently, these thermodynamic elements influenced the evolution of inertial-gravity waves.  相似文献