材料期刊网

COMPUTERIZED SIMULATION AND EXPERIMENTAL RESEARCH ON SOFT-SWITCHING ARC WELDING INVERTER POWER SOURCE

S. J. Chen , S. Y. Yin , L. Feng and L. Y. Li( 1) School of Materials Science and Engineering , Beijing Polytechnic University , Beijing 100022 , China 2)National Key Laboratory of Advanced Welding Production Technology , HIT , Harbin 150001 , China)

金属学报(英文版)

Based on the existing component models in the Pspice software package, a combined model for Insulat- ed the Bipolar Transistor (IGBT) is established, in which a non - linear is introduced to represent the parasitic capacitance. Using this model, computerized simulation is conducted for the FB - ZVZCS - PWM soft - ewitching converter,the switching and energy-transferring characteristics of the components are analyzed.The simulation results are testified by experiments.It is proved that by abopting appropriate models,computerized simulation becomes an effective tool for investigation of arc welding inverter power source.

关键词: arc welding inverter , null , null

Fe2+对嗜铁钩端螺旋菌L. ferriphilum生长活性的影响

高健 , 康健 , 吴学玲 , 徐競 , 李邦梅 , 邱冠周

中国有色金属学报

以分离于江西某铜矿的嗜铁钩端螺旋菌(L. ferriphilum YSK)菌株为研究对象,报道不同Fe2+浓度对 L. ferriphilum生长活性的影响.结果表明,YSK菌株生长最适宜的Fe2+浓度约为0.1 mol/L.当初始Fe2+浓度为0.4 mol/L时,进入对数生长期前很明显需要一个较长的延迟期,表明该Fe2+浓度对细胞的生长产生较强的抑制作用;当初始Fe2+浓度为0.6 mol/L时,YSK菌株的生长完全受到抑制.尽管高浓度的Fe2+抑制细胞的生长,但受到抑制而不生长繁殖的YSK细胞仍然具有氧化Fe2+的能力.

关键词: L.ferriphilum YSK菌株 , Fe2+ , 生长活性

Distribution, Transportation and Cytolocalization of Neodymium in Oilseed Rape (Brassica napus L.)

魏幼璋

稀土学报(英文版)

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Distribution, Transportation and Cytolocalization of Neodymium in Oilseed Rape (Brassica napus L.)

魏幼璋

稀土学报(英文版)

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Distribution, Transportation and Cytolocalization of Neodymium in Oilseed Rape (Brassica napus L.)

魏幼璋

稀土学报(英文版)

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Distribution, Transportation and Cytolocalization of Neodymium in Oilseed Rape (Brassica napus L.)

魏幼璋

稀土学报(英文版)

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Distribution, Transportation and Cytolocalization of Neodymium in Oilseed Rape (Brassica napus L.)

魏幼璋

稀土学报(英文版)

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Distribution, Transportation and Cytolocalization of Neodymium in Oilseed Rape (Brassica napus L.)

魏幼璋

稀土学报(英文版)

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L1(2)- and L1(0)-like cation-ordered structures in ZrO2-Y2O3 ceramics

Journal of Materials Research

Y0.25Zr0.75O2-x and Y0.5Zr0.5O2-y phases, with L1(2-) and L1(0-) like cation-ordered structures, respectively, have been found in ZrO2-Y2O3 ceramics in both the sintered and annealed states. High-resolution electron microscopy, energy-dispersive x-ray spectroscopy and computer simulation have been used to reveal the presence of the phases. The formation of Y0.25Zr0.75O2-x, and Y0.5Zr0.5O2-y phases was initiated during the sintering procedure and developed with the increase in annealing temperature and time. Segregation of yttrium, which was prevalent in different regions even within one grain, induced the formation of Y0.25Zr0.75O2-x and Y0.5Zr0.5O2-y phases.

关键词: yttria-stabilized zirconia;percent y2o3 alloy;x-ray-diffraction;solid-solutions;electron-diffraction;neutron-diffraction;modulated;structure;diffuse-scattering;average structure;tetragonal phase

Effect of Low Concentration of Yttrium on Physiological Characteristics of Cucumber (Cucumis Sativus L.)

稀土学报(英文版)

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