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华东地区围护结构节能研究 总被引:2,自引:0,他引:2
根据南京市的典型年逐时气象参数,对于该市的某一座高层建筑物,应用自编的逐时动态负荷模拟程序,输入围护结构(窗户、墙体和屋顶)相关的物理参数及其与周围环境的关系(地点及朝向等),计算围护结构冬季采暖期散热量及夏季制冷得热量。结果表明,采用双层塑窗代替单层塑窗,使用节能墙体代替传统墙体能够使得冬季围护结构传散热量减少51%,夏季围护结构总得热量减少46%。因此,这一结果为华东地区建筑节能技术提供了理论依据。 相似文献
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Adverse effects of microgravity on the magnetotactic bacterium Magnetospirillum magnetotacticum. 总被引:2,自引:0,他引:2
J E Urban 《Acta Astronautica》2000,47(10):775-780
Bacteria that contain magnetosomes display magnetotaxis and align themselves to the earth's magnetic field. When magnetotactic bacteria were first isolated several decades ago it was presumed that geomagnetic orientation allowed magnetotactic bacteria to orient themselves downward towards sediments where the habitat is favorable to their growth and metabolism. As more species of magnetotactic bacteria have been isolated and studied, differences in magnetotactic responses have been observed which suggested that the primary role of magnetosomes might simply be to enhance a microorganism's response to gravity. To resolve if gravity influences magnetotactic behavior in bacteria, Magnetospirillum magnetotacticum was used to examine magnetotaxis in the absence of gravity. Experiments to compare the orientation of bacteria to north- or south-pole magnets were conducted in normal gravity and in the microgravity environments aboard the Space Shuttle and Space Station MIR. In each of the microgravity situations studied, bacteria were impaired in their ability to orient to magnets and the failure to exhibit magnetotaxis appeared to be a function of the loss of magnetosomes. The disappearance of aggregated magnetosomes seemed to correlate with a general loss of cellular integrity in microgravity. 相似文献
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Bacteroids can be induced in vitro by treating growing Rhizobium leguminosarum bv. trifolii with succinic acid or succinic acid structural analogs like acetysalicylic acid. Quantitating bacteroid induction by measuring acetylsalicylic binding under normal (1 g) conditions showed two forms of binding to occur. In one form of binding cells immediately bound comparatively high levels of acetylsalicylic acid, but the binding was quickly reversed. The second form of binding increased with time by first order kinetics and reached saturation in 40 s. Similar experiments performed in the microgravity environment aboard the NASA 930 aircraft showed only one form of binding and total acetylsalicyclic acid bound was 32% higher than at 1 g. 相似文献
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A. Urban K.M. Torkar J. Bjordal J.A˚. Lundblad F. Søraas B. Grandal L.G. Smith J.C. Ulwick R.P. Vancour 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1982,2(10):77-80
Measurements of the precipitation of electrons and positive ions (in the keV to MeV range) detected aboard eight rockets launched from Northern Scandinavia are reported together with corresponding satellite data. The downgoing integral fluxes indicate the temporal fluctuations during each flight. Height profiles of the energy deposition into the atmosphere at different levels of geomagnetic disturbance are given. 相似文献
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