共查询到20条相似文献,搜索用时 78 毫秒
1.
晟 《小型内燃机与摩托车》1985,(3)
我国机动车的正式牌照都是七位数字,前列二位数字为省、自治区、直辖市的代号,后列五位数字为车辆的编号.代号的分配是:北京01,河北02,内蒙古03,山西04,辽宁05,吉林06,黑龙江07,上海08,江苏09,浙江10,安徽11,江西12,福建13,山东14,广东15,广西16,湖北17,湖南18,河南19,四川20,云南21,贵州22,西藏23,陕西24,甘肃25,青海26,新疆27,宁夏28,天津29.空下"30"是留给台湾省的. 相似文献
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《热科学学报(英文版)》2003,(4)
Editorial Advisory BoardAUNG,WinCHEN,Xue JunGAL一OR,BenGRUNDMANN,RogerIV人NOV, MiehailLEONTIEV, A.I.MA,TongZeNAKORIAKOV, VESWITHENBANK,J.认钱NG,Bu XuanWU,Cheng KangZIEREP, JuergenU.SA.ChillaIsraelGermanyRussiaRussiaChinaRtlssiaUnited瓦ngdomChiflaChinaGenllanyBERGLES,Arthllr E.DVORAK,RudolfGALLUS,HE.HUANG,Zhao XiangLEFEBVRE,A.H.MA,Chong一FangMARTYNENKO,O.G.RAUTENBERG,ManfredTIEN,Chang LinWENG,Shi LieYE,Da JunU:S A.CzeehG… 相似文献
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INTaoDUCTIONDuetohighenthalPychemicalactivityandcon-tr0llableatmophere,thermalplasmajetreactorshavebeenextensivelyutilizedinmodernindustrysuchasmetallurgy,materialsprocessing,aerospace,electron-ics,autom0bile,biomedicine,wastemanagementandsoon.Il-3]PowdermaterialproductiQnisatypicalexampleofplasmatechnologyaPplications.Inthiscase,mass,momentumandenergytransferprocessesbetweentheplasmagasandinjectedparticlesarethedominatmechwhsmswhichgovernthemixing,mov-ingandheating0fthematerialparticlesb… 相似文献
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三门湾地处浙东沿海,亦即全国东海岸中段和华东沿海中心,北衔宁波,南近温州,湾内水深长期保持不变;东岸奇峰叠翠。绵延曲折,形成多个深水港汊嵌入内陆,西面天台山系蟠结耸峙,蜿蜒逶迤,舒展入海;湾外东海波涛汹涌,航程万里,湾内珠岛星罗棋布,平静如镜,气候温和,雨量充沛,山溪汇集,物产丰富,素有“浙东 相似文献
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李庆生 《能源技术(上海)》2001,22(1):32-34
通过工程功能,供电方案,设备选择等方面,叙述水利工程设计中应用节能技术的经验,根据上海河道受潮汐影响大的特点,最大限度提高自排能力,以节制闸自排为主,减少水泵强排,合理规划排水模式,充分利用景观绿化和人工水面,增加河道蓄洪能力,科学调度,使城市排水功能所用电耗降到最低,选用10kV主水泵电动机直接联网运行,实现功率因数就地补偿,合理配置电力变压器,减少电能损耗,选择合适参数的节能与设计,节约电能。 相似文献
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我厂是生产气缸套产量较大厂家之一,年产缸套毛坯110万件,12000多吨,年铁屑量6000~7000吨,铁屑的回收以冷压块为主,自78年以来,铸工车间一直使用二台中央送风冲天炉,雨淋式外水冷,金属炉料中加入25~30%的冷压块。冷压块加火炉内,易碰碎或砸碎,碎铁屑在风力的作用下,吹向炉壁,在高温下烧结成一体,挂在炉胆下沿的炉壁上,如图1所示,严重时挂铁厚度达100~150mm,高1000~1500mm,使熔化率下降,架料、氧化次数增多,只好停产,清理挂铁,用电焊机割铁,要用许多焊条,既影响了生产,又浪费了材料,且雨淋式冲天炉由于冷却水量不均匀,造成炉衬侵蚀不同,侵蚀严重的部位,易造成挂 相似文献
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叙述了目前运城市环境质量状况较差,资源利用效率低下,污染物排放量增大,城镇乡村基础设施滞后的情况,提出,转变观念,宣传教育,搞好规划,调整结构,健全法制,完善政策,依靠科技,示范推广等解决环境问题的思路。 相似文献
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利用高速摄像技术研究气流通过浸没垂直导管口在液体中形成气泡的机理及其行为规律,分析导管内径、气体流量、导管口浸没深度和导管外径对气泡脱离直径的影响。结果表明:在导管内径分别为7、10和14 mm,气体流量在0~450 mL/s的条件下,气泡脱离直径随导管内径和气体流量的增加而增大;在浸没深度为0.05~1 m的条件下,导管口浸没深度对气泡脱离直径的影响很小可以忽略;当气体流量在100 mL/s以上,导管内径为10 mm、导管外径为14~26 mm时,随着导管外径的增加,气泡脱离直径减小。 相似文献
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The reflectivity of the bottom of a solar pond increases on account of the accumulation of dirt or the presence of undissolved salt. The effect of the reflection of the solar radiation at the bottom of the pond on the seasonal performance of the pond has been studied using a three zone model. The spectral reflectivity of dirt and common salt were measured in the laboratory and used in the analysis. The results obtained from the analysis show that the presence of dirt at the bottom of the pond does not affect the performance of the pond substantially. On the other hand, the presence of undissolved salt at the bottom of the pond results in substantial deterioration of the pond performance. 相似文献
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It has been proposed to introduce a new parameter into the practice of the heat calculation and testing of the flat-plate solar water-heating collectors (FSWHCs)—the coefficient of heat transfer from the light-absorbing panel (LAP) to the heat transfer fluid in its internal heat-exchange channels (HECs) reduced to the unit area of the frontal surface of their cases. The mechanism of the formation of this parameter is studied, the design expression is derived, and a practical example of the calculation to define its value is performed. The structures of the flowing LAPs of a sheet-piped thin parallelepiped form are selected as the objects of the investigation. The reliability of the results of the investigations is proved by comparing the values of the specific (relative to the area unit of the frontal surface of the case) heating efficiency of the collector obtained based on the various formulas. 相似文献
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The problems of the transportation energy and environment are the major challenges faced globally in the 21st century and are especially serious for China. The future 20 years is the strategic opportunity period of the transition of the transportation energy and powertrain system for China. The greatest characteristics of hydrogen economy lie in its diversity of the primary energy source, the unification of energy carrier and the greening of energy transformation. Development of hydrogen energy transportation powertrain system is suitable for China from the views of the situation of Chinese resources and energy sources, the urban and rural layouts, the superiority of later development and the successful practices of clean cars and electric vehicle development projects. The transition of the transportation energy powertrain system includes three parts: the transition of the energy structure, the transition of the powertrain system and the transition of the fuel infrastructure. The technical pathways of energy powertrain system transition includes expending the use of gaseous fuel to prompt the multiform of the transportation energy and to prepare for the transition of the infrastructure simultaneously, developing and promoting the hybrid technology to solve the current energy and environment problems and to prepare for the transition of powertrain system, and focusing on the research and development and demonstration of fuel cell vehicles and the hydrogen energy technology to prompt the earlier formation of the market of fuel cell vehicles. The goal in the near and medium term of transition is to reduce the fuel consumption by 100 million ton in 2020 by substituting and saving, and the long-term goal is to setup the infrastructure of hydrogen and fuel cell vehicle as the main one replacing the petroleum internal combustion engine vehicle. In order to realize the strategic goals of the transition, the four-phases strategic periods and research and development activities are discussed and proposed. 相似文献
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抽水蓄能电站甩负荷过渡过程中,内部流场与外部结构双向作用,对球阀安全运行造成不良影响。为探讨抽水蓄能电站甩负荷工况球阀动态关闭过程中流场演变对球阀关键部件的影响,基于流固耦合理论,建立球阀系统离散角度有限元仿真模型,以多角度结构分析近似模拟球阀在动水关闭过程中的结构瞬态过程,反映球阀流道的分布特点及薄弱环节的数据特征。为此,先对某抽水蓄能电站进行数值模拟,提取甩负荷过渡过程关键参数,根据仿真结果确定球阀流场边界条件;然后计算球阀流道内流场压力与速度分布;最后基于流场仿真结果建立球阀结构流固耦合模型,求解球阀瞬态过程结构强度相关参数分布。结果表明,甩负荷过渡过程中,在水流三维瞬变流动的影响下,球阀结构的应力分布具有明显规律性,工作密封与检修密封的过流面积突变,导致应力极大值出现在基座与枢轴部位。流场作用于球阀壁面的变形量叠加,球阀总变形量呈现由上游至下游逐渐递增的趋势。 相似文献
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V. Zubkova A. Strojwas M. Walczak 《Energy Sources, Part A: Recovery, Utilization, and Environmental Effects》2016,38(10):1318-1325
The mechanism of influence of the addition of 2 wt% of the expired pharmaceuticals (EPs) containing 80% of ibuprofen ((RS)-2-[4-(2-methylpropyl)phenyl]propanoic acid) on the transformation of the ordered structure of the three coals of different ranks was studied. The co-pyrolysates of coals with EP additive were studied with the method of X-ray diffraction (ХRD) and scanning electron microscopy (SEM). It was stated that the addition of 2 wt% of EP to all coals under study increases the intra-crystalline ordering. Under the influence of the addition of 2 wt% of EP at the stage of swollen grains of the co-pyrolysates of all coals, the amount of carbon ordered in crystallites decreases. In the co-pyrolysates of lower-rank coals (LRC) and higher-rank coals (HRC) under the influence of this additive at the stage of coke, the amount of the ordered phase decreases compared to the pyrolysates. In the co-pyrolysate of a medium-rank coal (MRC), the degree of ordering of coke does not change compared to the coke from single coal. 相似文献
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《International Journal of Hydrogen Energy》2021,46(68):33670-33678
Traditionally, the determination of static load characteristics is one of the main stages in the preparation of a design model of an electric power system. It is especially important to correctly take into account energy-intensive industries, which make a huge contribution to the formation of these characteristics. In particular, the increased interest in hydrogen technologies observed in the world as one of the most promising high-tech areas of energy development, and an increase in the share of the installed capacity of generation units based on renewable energy sources determine the prospects for the development of hydrogen production by water electrolysis. Accordingly, a significant increase in the scale of application of hydrogen technologies, in particular, in accordance with the “Hydrogen Strategy for Climatically Neutral Europe”, the European Commission for the production of “green” hydrogen, determines the task of forming correct mathematical models of these devices in terms planning of modes, analyzing their impact on the parameters of electric power systems. Determination of static load characteristics on the basis of a physical experiment will not allow obtaining a characteristic with a significant increase or decrease in voltage in the node of the electric power system, which occur only in emergency modes of operation of the power system. Therefore, it seems relevant to analyze and determine the electrical characteristics of consumers by mathematical modeling of the power circuit. This article presents the results of correcting the static load characteristic of a high-power electrolyzer used in the production of hydrogen. The analysis of these results obtained with the MATLAB software is carried out using least squares regression to procure polynomial functions of the static load characteristics. According to this analysis, the static characteristics of the considered electrolyzer, being close to linear within the control range, outside the control range acquire parabolic dependences of active and reactive power on voltage. The static load characteristics of the installation are determined by the parameters of the power circuit and the current-voltage characteristic of the rectifiers displacing the vertices of the parabolas from the origin, which should be taken into account to increase the reliability of the design scheme. 相似文献