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高精度的流体热物性实验研究是新工质工程应用的必要基础,也是获取部分基础物理常量的重要途径(如声速法测量玻尔兹曼常数k、通用气体常数R).本文建立了高精度的流体热物性实验系统,包括温度测量和恒温系统、压力测量及真空配气系统,实现了实验系统的自动控制与数据采集.可用温度范围-40~180℃,不确定度为±5 mK;压力范围0~10 MPa,不确定度为±50 Pa(0~130 kPa),±100 Pa(130~3000 kPa),±0.01%(3~10 MPa).进行了HFC-227ea的饱和蒸气压验证性实验,结果表明本系统运行稳定,具有较高测量精度. 相似文献
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质子交换膜燃料电池是-种能量转换装置,具有效率高、噪音低、无污染等优点。本文使用正交实验法和方差分析法研究了流场板结构、运行温度、阴阳极相对湿度和阴阳极流量对电池性能的影响,并对电池性能进行了优化.性能指标采用最大功率和最高效率。研究结果表明,流场板结构和运行温度对最大功率有显著影响,流场板结构和阳极流量对最高效率有显著影响。对所研究的电池下列组合可得最优性能:蛇形流场板-运行温度70℃阴极相对湿度0%-阳极相对湿度100%-阴极流量0.263 SLPM-阳极流量0.525 SLPM。 相似文献
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Two Cd(II) complexes, Cd2L2Cl2(1) and Cd2L2(NCS)2(2)(HL = N-(3-methoxyl-salicylidene)-3-dimethylaminopropylamine) were synthesized and determined by EA, IR, TG and single-crystal X-ray diffraction.The crystallographic data are as follows:monoclinic, space group P21/n, a = 9.2710(9), b = 18.0069(18), c = 18.5562(19) , β = 99.741(4)o, V = 3053.1(5), Z = 4, μ = 1.605, F(000) = 1536, R = 0.0264 and wR = 0.0699 for 1;orthorhombic, space group Pca21, a = 16.196(3), b = 11.506(2), c = 36.126(7), V = 6732(2), Z = 8, μ = 1.428, F(000) = 3264, R = 0.0376 and wR = 0.0877 for 2.There are two geometrically different octahedral Cd(II) atoms, with N4O2 and O4Cl2 donor sets for 1 while N4O2 and N2O4 for 2.In the dinuclear Cd(II) centers, the Cd(II) atoms are held together by two deprotonted phenolate oxygen atoms from tetradentate L-ligands.The thermal gravity data show two step decompositions with the residues of CdO for two complexes. 相似文献
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1 INTRODUCTION Organic-inorganic hybrid material has captured the imaginations of chemists due to its potential applications in electric conductivity, magnetism, ion exchange and catalysis[1~2]. Coordination polymers with special structures have been well prepared by the reaction of transition metal ions and special orga- nic ligands. As a kind of multi-dentate ligand, aro- matic polyoxybiontic anion can coordinate with metal ion to form chain, layer and network struc- tures[3~6]. 1,3,5… 相似文献
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声学共鸣法是目前测量流体热物性、热力学温度和玻尔兹曼常数最精确的方法之一,声波导管为共鸣腔提供声源和气体进入口,但是会破坏共鸣腔的理想表面从而导致腔体内气体介质共鸣频率的偏移(△f)和共鸣峰半宽的增加(g)。本文从一阶声学微扰出发建立了声波导管对共鸣腔声场的扰动模型,分析了导管位置、长度和半径大小对腔体中介质共振频率的影响。进一步测量了52~1763 mm之间六个不同长度的导管在T=332 K和p=50~500 kPa时,圆柱共鸣腔中轴向共鸣模式的共鸣频率和半宽的变化,测量结果与理论计算值吻合较好,证明了理论模型的正确性。 相似文献