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21.
Chenglong Zhang Jingming Fei Lei Guo Jianxing Yu Binbin Zhang Zheng Yan Fuxing Ye 《Ceramics International》2018,44(8):8818-8826
LaPO4 powders were produced by a chemical co-precipitation and calcination method. The ceramic exhibited a monazite structure, kept phase stability at 1400?°C for 100?h, and had low thermal conductivity (~ 1.41?W/m?K, 1000?°C). LaPO4/Y2O3 partially stabilized ZrO2 (LaPO4/YSZ) double-ceramic-layer (DCL) thermal barrier coatings (TBCs) were fabricated by air plasma spray. The LaPO4 coating contained many nanozones. Thermal cycling tests indicated that the spallation of LaPO4/YSZ DCL TBCs initially occurred in the LaPO4 coating. The failure mode was similar to those of many newly developed TBCs, probably due to the low toughness of the ceramics. LaPO4/YSZ DCL TBCs were highly resistant to V2O5 corrosion. Exposed to V2O5 at 700–900?°C for 4?h, La(P,V)O4 formed as the corrosion product, which had little detrimental effect on the coating microstructure. At 1000?°C for 4?h, a minor amount of LaVO4 was generated. 相似文献
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分析离散型按订单生产的中小企业生产过程,建立生产计划系统模型,采用模拟退火算法设计了基于订单的生产计划和排程系统. 相似文献
23.
用一步法合成DMDAAC单体,采用APS—TEA复合引发体系引发聚合得到PDMDAAC。实验取100mL质量分数为72%的DMDAAC溶液,通N2 30min后加入APS 0.548g、TEA0.352g、EDTA·2Na 15.04mg,当反应温度为42℃,反应时间为24h时,DMDAAC的转化率为82.26%,PDMDAAC的特征粘度为1.06dL/g。采用PFS(聚合硫酸铁)、PDMDAAC和PFS—PDMDAAC复合絮凝剂处理Cu^2+、pb^2+浓度均为10mg/L的模拟重金属污水,PFS—PDMDAAC复合絮凝剂处理效果最好。控制模拟污水的终点DH值约为8.5,使用PFS-PDMDAAC复合絮凝剂,当PFS剂量为5.52mg/L、PDMDAAC剂量为0.39mg/L时,处理后Cu^2+、Pb^2+去除率分别达到99.8%和99.9%。 相似文献
24.
文中介绍了应用于高光谱地球观测的CMOS有源图像传感器。该器件由全局曝光模式的像素组成512×256面阵,可实现450帧/s的帧频。全局曝光模式是由在光二极管外增加1个储存电容的方式实现的。该器件采用0.5μm标准CMOS工艺,满阱电子达到140 000电子,瞬态噪声29电子,动态范围74 d B。采用该器件开发的高光谱成像仪的空间及频谱分辨率具有很高水平。 相似文献
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提出一种LCC谐振变换器的非对称移相控制方法。该方法采用PWM移相混合调制方式,有两个控制变量,实现了更高的控制自由度。分析LCC谐振变换器的稳态特性,包括输出功率特性、软开关特性以及谐振电流特性。分析结果表明,不同的控制变量组合能够实现同一输出功率,但会导致软开关及谐振电流特性发生变化。在此基础上提出一种效率优化策略,使谐振变换器在输出功率不变的情况下谐振电流降至最低,同时保证了软开关的实现。所提出的方法能够进一步提升LCC谐振变换器的效率。通过仿真及1.9k W样机验证了理论分析及所提控制方法的可行性和有效性。 相似文献
27.
Zhou Zheng Wang Lu He Dingyong Liu Yanbo Zhang Guanzhen Beijing University of Technology Beijing China Beijing Institute of Technology Beijing 《稀有金属材料与工程》2011,(Z3)
Amorphous metallic coatings with a composition of Fe48Cr15Mo14C15B6Y2 were prepared by means of atmospheric plasma spraying (APS) process under different conditions. The microstructure and frictional behavior were characterized simultaneously in this article. The results show that the as-deposited coatings consist of amorphous matrix and some precipitated nanocrystals, while the amorphous fraction and particle deformation as well as crystallization mechanism are significantly sensitive to the spraying param... 相似文献
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从提出和分析PTN网络保护技术现状问题出发,总结PTN环网保护对运营商的重要意义。通过研究PTN环网保护技术的原理和实现机制,对不同技术方案、技术标准的优缺点进行分析总结,同时也提出了笔者自己的观点和看法,提出了环网保护技术配置方案建议,最后对环网保护技术及PTN网络未来发展趋势进行了展望。 相似文献
30.
Parul Gupta Anand GhosalkarSaroj Mishra Tapan Kumar Chaudhuri 《Journal of Bioscience and Bioengineering》2009,107(2):102-107
A major portion of the over expressed yeast mitochondrial aconitase, a large 82 kDa monomeric TCA cycle enzyme, in Escherichia coli led to the formation of inclusion bodies. Bacterial chaperonin GroEL mediated the correct folding of aconitase with the assistance of its co-chaperonin GroES in an ATP dependent manner. Till date the chaperonin assisted folding of aconitase was limited to the shake flask studies with relatively low yields of folded aconitase. No attempt had yet been made to enhance the yield of chaperone mediated folding of aconitase using a bioreactor. The current report deals with the effect of co-expression of GroEL/GroES in the production of soluble, biologically active recombinant aconitase in E. coli by cultivation in a bioreactor at different temperatures under optimized conditions. It revealed that the yield of functional aconitase was enhanced, either in presence of co-expressed GroEL/ES or at low temperature cultivation. However, the outcome from the chaperone assisted folding of aconitase was more pronounced at lower temperature. A 3-fold enhancement in the yield of functional aconitase from the bioreactor based chaperone assisted folding was obtained as compared to the shake flask study. Hence, the present study provides optimized conditions for increasing the yield of functional aconitase by batch cultivation in a bioreactor. 相似文献