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601.
Christian Hill 《Journal of Molecular Spectroscopy》2007,241(1):7-14
The spin-spin centrifugal distortion Hamiltonian for an asymmetric top molecule in a given vibrational level of an open-shell electronic state with S ? 1 may contain more parameters than can be determined from the observed energy levels. This paper describes the reduction of the Hamiltonian by means of a unitary transformation to a form suitable for fitting to observed energies. It is established that there are six determinable spin-spin centrifugal distortion parameters for a molecule of orthorhombic symmetry; the corresponding matrix elements are derived for both Hund’s case (a) and case (b) coupling schemes. 相似文献
602.
Baldermann S Mulyadi AN Yang Z Murata A Fleischmann P Winterhalter P Knight M Finn TM Watanabe N 《Journal of separation science》2011,34(19):2759-2764
Centrifugal precipitation chromatography and a high-speed counter-current chromatography system equipped with a spiral tubing support rotor (spHSCCC) were successfully applied for the identification and isolation of carotenoid cleavage-like enzymes from Enteromorpha compressa (L.) Nees. This is the first study separating active enzymes from a complex natural matrix by spHSCCC. The target enzymes were identified after fractionation of the proteins in an acetone Tris-buffer gradient by centrifugal precipitation chromatography. Also, an aqueous two-phase solvent system consisting of PEG 1000 and mono- and dibasic potassium phosphate was used for the isolation of the enzymes by spHSCCC. The purified fractions contained two proteins of 65 and 72 kDa, respectively. The enzymes could cleave β-carotene and β-apo-8'-carotenal to produce β-ionone. 相似文献
603.
Experiments were conducted to measure and to clarify quantitative variations of fluid force on three kinds of setting blade configuration on a Savonius rotor at the static state in the steady uniform flow. In the experiments, by splitting both the end-disks of the blades into two half parts, the two blades were independent on each other and the one blade attached to both the half end-disks was only connected to the axis rod of the rotor, and the other blade connecting to the other half end-disks was free from the axis rod. Hence, the drag and lift forces acting on the former blade were directly measured in a short time at every phase angle and every overlap ratio of the two blades using the force balance meter. The experiment for the rotor of the diameter 160 mm and the height 160 mm was conducted in the steady wind flow of the Reynolds number, about 0.64 × 105 which based on the rotor diameter and the upstream velocity. From the experiment, value of the drag coefficient of the one blade in two blades with the overlap ratio of zero was taken from about −0.3 to 1.6, and the lift coefficient of it from about −1.0 to 1.4 in a cycle. The minus value of drag only appears in the setting of one blade in two blades, however the minus value does not exist in the distribution of tangential force on every overlap. And it was shown that the force distributions on the one blade in a cycle were very different in the first and second half cycle and interfered by the other blade, and strongly dependent on the overlap ratio between the blades. 相似文献
604.
605.
基于近似模型的透平机械多目标优化 总被引:2,自引:0,他引:2
本文研究了采用多目标优化算法NSGA—II与前馈神经网络的耦合优化方法的收敛性问题。提出了一种改进的拥挤距离和coarse-to-fine的迭代策略,有效地解决了原耦合方法不收敛的问题。在此基础上,提出了基于数值模拟和耦合优化方法的多目标气动设计框架,并对转子37进行了三目标优化。优化结果表明,多目标优化结果的气动性能... 相似文献
606.
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609.
将理论推导和数值模拟相结合,对典型离心压缩机Eckardt叶轮流场进行分析,探讨了不同进气预旋对叶轮气动性能的影响;从叶片进口攻角、叶尖相对马赫数和流向压力变化的角度,阐述了预旋对内部流动以及气动性能的影响机理。结果表明:预旋角对进口攻角和叶尖相对马赫数同时产生显著影响,正预旋会降低进口来流的攻角及相对马赫数,使叶片前缘载荷降低、叶轮效率及稳定性提升;负预旋会提升叶轮的做功能力,使总压比上升;正预旋由于降低了叶片前部做功能力,使低压流体堆积到叶片中后部,导致总压比下降;叶轮最高效率受叶尖相对马赫数与进口攻角共同影响,若提升效率必须合理协调预旋对二者的影响。 相似文献
610.
《Analytical letters》2012,45(8-9):591-597
Abstract Two new rotors have been designed and developed for use with Centrifugal Fast Analyzers. These rotors incorporate separate sample and reagent chambers and transfer channels, which prevent premature mixing of the aliquots of sample and reagent and also provide for their simultaneous and rapid transfer and mixing when the rotor is accelerated. 相似文献