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91.
多联式空调机组的应用 总被引:1,自引:1,他引:1
分析了多联式空调机组的系统匹配、室内外机配比、室内外机之间的管长和高差对制冷量和制热量的影响,给出了确定室内外机容量的方法。 相似文献
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A large-scale antenna system(LSAS) with digital beamforming is expected to significantly increase energy efficiency(EE) and spectral efficiency(SE) in a wireless communication system. However, there are many challenging issues related to calibration, energy consumption, and cost in implementing a digital beamforming structure in an LSAS. In a practical LSAS deployment, hybrid digital-analog beamforming structures with active antennas can be used. In this paper, we investigate the optimal antenna configuration in an N × M beamforming structure, where N is the number of transceivers, M is the number of active antennas per transceiver, where analog beamforming is introduced for individual transceivers and digital beamforming is introduced across all N transceivers. We analyze the green point, which is the point of maximum EE on the EE-SE curve, and show that the log-scale EE scales linearly with SE along a slope of-lg2/N. We investigate the effect of M on EE for a given SE value in the case of fixed NM and independent N and M. In both cases, there is a unique optimal M that results in optimal EE. In the case of independent N and M, there is no optimal(N, M) combination for optimizing EE. The results of numerical simulations are provided, and these results support our analysis. 相似文献
95.
中国可持续发展城市降温广州试点项目组 《城市规划》2021,45(6):52-62
全球人口城市化率在超过50%后持续上升和全球气候变化是当前世界各地城市发展面临的两大趋势.随着城市人口和开发建设的高度集聚,城市热环境过载问题日益突显,对城市带来复杂且持续的影响.这一问题的解决与联合国2030年可持续发展目标的17个领域均直接相关,可作为统筹推进城市可持续发展的重要抓手.本文结合世界银行2020年在广州市启动的全球首个可持续降温试点项目阶段成果,展示并总结以"清凉城市"为主题的城市可持续转型新模式:助力中国城市应对气候变化,贡献实现碳中和路径,面向可持续发展综合目标,聚焦关键问题,通过国际合作和知识共享,以系统化思维构建集成化的解决方案,并促进方案高效实施. 相似文献
96.
TONG YaBo YANG ZhenYu PAN YongXin ZHENG Li i SUN ZhiMing PEI JunLing &ZHUANG ZhongHai Institute of Geomechanics Chinese Academy of Geological Sciences Beijing China 《中国科学:技术科学(英文版)》2011,(4)
Geomagnetic polarity transitions were the most important phenomena in the study of the geomagnetic field evolution and the earth's deep interior dynamics.The Miocene postcollisional ultrapotassic-potassic rocks are widely distributed in the Lhasa Block of southern Tibet.Paleomagnetic studies on the Wuyu Formation indicated that these volcanic rocks recorded the C5Bn.2n-C5Bn.1r and C5ACr-C5ACn geomagnetic polarity transitions.The virtual geomagnetic poles(VGPs) of these two polarity transitions were located ... 相似文献
97.
JIANG XueJun LIN XueHui YAO De & GUO WeiDong Key Laboratory of Marine Oil Gas Resources Marine Environment Ministry of L Resources Qingdao China Qingdao Institute of Marine Geology China Geological Survey 《中国科学:技术科学(英文版)》2011,(2)
A series of selective extraction experiments were conducted on marine hydrogenic ferromanganese crusts from the seamount near the Line Island to investigate the distribution of rare earth elements(REEs) and the mechanisms of combination between REEs and the hydrogenic ferromanganese crusts.The enrichment of REEs in hydrogenic ferromanganese crusts is attributed mainly to the mineral or oxide/hydroxide of the crust rather than the growth environment.The REEs are present mainly in amorphous ferric oxide/hydro... 相似文献
98.
FANG JiaSong & ZHANG Li State Key Laboratory of Marine Geology Tongji University Shanghai China College of Natural Computational Sciences Hawaii Pacific University Kaneohe HI USA State Key Laboratory of Geological Processes Mineral Resources Faculty of Earth Sciences China University of Geosciences Wuhan 《中国科学:技术科学(英文版)》2011,(2)
Over the past two decades, scientific drilling into sediments and rocks in the ocean and the continent has revealed the presence of physiologically and phylogenetically complex microbial life in the deep subsurface. Microorganisms, most of which have no cultured or known relatives in the surface biosphere, have been discovered in sediments and rock at depth as deep as 1 km below the seafloor and more than 3 km deep in the continent. The deep biosphere probably represents the most voluminous part of the glob... 相似文献
99.
ZHAO Ming JI JunFeng CHEN ZhenYan CHEN XiaoMing CUI XiangDong & WANG YanShan School of Earth Sciences Engineering Nanjing University Nanjing China Exploration Development Institute Liaohe Oilfield Panjin 《中国科学:技术科学(英文版)》2011,(1)
The oil-rich Damintun Depression is located in the Liaohe Basin, Northeast China, and was formed during the Paleogene. The major oil-producing strata in the depression are mudstone and shale. To explore the burial diagenetic history of the basin and the formation thresholds of hydrocarbons, the characters of the kaolinite subgroup minerals and mixed-layer illite/smectite in the mudstone and the shale are studied by using X-ray diffraction, electron probe, scanning electron microscope, and Fourier infrared s... 相似文献
100.
DU XueBin Lanzhou Institute of Seismology China Earthquake Administration Lanzhou China Lanzhou Base of Earthquake Science Institute 《中国科学:技术科学(英文版)》2011,(1)
Two types of changes in apparent resistivity (AR) have been linked to earthquake occurrences. This paper studies the changes and their causes, in detail with the ultimate purpose of developing and assessing a method of earthquake (EQ) prediction. The AR changes of the first type (CFT) are considered to be precursors related to earthquakes (EQs); these appear mostly in the medium-term period before EQs and in the short-term period preceding EQs. The changes of the second type (CST) are characterized by a tur... 相似文献