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41.
Xiling Yao Seung Ki Moon Guijun Bi Jun Wei 《The International Journal of Advanced Manufacturing Technology》2018,99(9-12):2111-2119
Additive manufacturing (AM) technologies provide more freedom to functional part design in various industries. One of the unique capabilities of AM is that multi-material parts can be produced with material compositional and geometric complexity. Multi-material parts have the advantage of achieving multiple performance requirements. In the research, we propose a framework for designing multi-material parts using AM processes. The proposed framework is composed of four interacting modules, including design requirement identification, primary material selection, AM process selection, material composition, and part geometry determination. Rules and guidelines for AM are integrated into the proposed framework with AM processes’ capabilities and constraints compiled in databases. We also introduce databases to assist in decision-making and ensure manufacturability of the designed multi-material part in various product design phases. The proposed framework is applied to a case study involving a conceptual design of a multi-material battery pack cooling plate. 相似文献
42.
43.
Hydrolytic stability is an essential requirement for polyurethanes (PUs) that are used in highly humid and aqueous environments. In this study, hydrolysis-resistant PU elastomers (PUEs) are synthesized based on hydrophobic bio-based polyfarnesene diol (PFD), which contains unique “bottle brushes” structure (with long branched hydrocarbon side chains). The effect of hard segment (HS) content, ranging from 30 to 50%, on the morphology and properties of PUEs is investigated by Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, X-ray diffraction, scanning electron microscopy, tensile, water absorption, and contact angle measurements. The results show that there are prominent phase separations in the synthesized PUEs. The PUEs show a three-stage degradation process and two Tg, one is at about −66 °C and the other 61 °C, which are related to the soft segment and HS, respectively. Water contact angles of PUEs increase from 98.6 to 105.2° with the increasing of PFD structural unit fraction. After being immersed in deionized water for 30 days, PUEs show no significant degradation of both tensile strength and elongation at break, and mass changes of all samples are less than 0.5%. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47673. 相似文献
44.
Duan Haiyang Wang Xudong Bai Yu Yao Man Guo Qingtao 《Metallurgical and Materials Transactions B》2019,50(5):2343-2353
Metallurgical and Materials Transactions B - Mold breakout is a catastrophic accident that has serious impacts on smooth production, slab quality, and caster equipment. Accurate identification and... 相似文献
45.
Photonic Network Communications - A low complexity carrier phase estimation (CPE) algorithm for M-ary quadrature amplitude modulation (m-QAM) optical communication systems is investigated in this... 相似文献
46.
苏里格气田是中国典型的致密砂岩气藏,构造简单、平缓,横向非均质性强,有效储层与围岩声学特征差别小,地震响应不明显,常规地震监测方法预测难度大,但气田含气砂岩泊松比低,是地震气藏检测的有效参数。利用弹性全波形反演精度高和能处理复杂非均质介质的优势,反演地层拉梅常数、剪切模量和密度,并计算泊松比,从而进行气藏预测。重点阐述了苏里格气田多分量数据全波形反演初始模型建模、先验模型建模和地震数据预处理3个关键问题的处理方法。二维三分量数据反演和"甜点"预测结果表明:①对于具有强非均质性的苏里格气田,利用全波形反演获得精度较高的地层弹性参数能显著提高气藏预测的准确度;②苏里格地区构造简单、平缓,利用常规叠加速度并结合构造解释可以建立比较好的初始模型,从而有效地解决了周波跳跃和局部极小的难题;③先验知识的约束和地震数据的预处理是全波形反演成功应用于苏里格气田气藏检测的关键。 相似文献
47.
Zhen Wu Jing Yao Pengfei Zhu Fusheng Yang Xiangyu Meng Sandra Kurko Zaoxiao Zhang 《International Journal of Hydrogen Energy》2021,46(19):11183-11198
Advanced biogas power generation technology has been attracting attentions, which contributes to the waste disposal and the mitigation of greenhouse gas emissions. This work proposes and models a novel biogas-fed hybrid power generation system consisting of solid oxide fuel cell, water gas shift reaction, thermal swing adsorption and proton exchange membrane fuel cell (SOFC-WGS-TSA-PEMFC). The thermodynamic, exergetic, and thermo-economic analyses of this hybrid system for power generation were conducted to comprehensively evaluate its performance. It was found that the novel biogas-fed hybrid system has a gross energy conversion efficiency of 68.63% and exergy efficiency of 65.36%, indicating high efficiency for this kind of hybrid power technology. The market sensitivity analysis showed that the hybrid system also has a low sensitivity to market price fluctuation. Under the current subsidy level for the distributed biogas power plant, the levelized cost of energy can be lowered to 0.02942 $/kWh for a 1 MW scale system. Accordingly, the payback period and annual return on investment can reach 1.4 year and about 20%, respectively. These results reveal that the proposed hybrid system is promising and economically feasible as a distributed power plant, especially for the small power scale (no more than 2 MW). 相似文献
48.
启发式分支策略是SAT求解器中不可或缺的一部分,直接影响求解器的效率。早期的启发式分支决策需要遍历整个子句数据库,效率比较低。随着独立变量状态衰减和(Variable State Independent Decaying Sum, VSIDS)分支策略的出现,SAT求解器的效率有所提高,但VSIDS策略以及它的延伸策略中变量的增量都只是与变量的冲突次数有关,没有考虑变量的决策层在分支策略中的影响。因此当发生冲突时,如果与冲突有关的变量的得分相同而决策层不同时,对于变量的选择就具有随机性。基于此,本文在阐述变量的决策层的重要性之后在VSIDS策略的基础上,提出一种基于变量决策层的启发式变量选择策略--HSVDL策略。然后通过实例显示HSVDL策略在变量决策阶段选择决策层低的变量的可能性比选择决策层高的变量的可能性要大,而且得分比较小,减少了内存的占用。最后通过实验表明HSVDL策略能够求解出更多的实例,求解器的效率也有所提高,说明该策略有一定的优势。 相似文献
49.
Taper grinding experiments were conducted in this paper to investigate the continuous and complete ductile-brittle transition process of two kinds of amorphous glass: high purity fused silica (HPFS) which is silica rich glass and soda-lime silica glass (SLSG) which is low silica glass. The grinding force, ground surface morphology, surface roughness, and subsurface damage depth induced during different stages of taper grinding were all analyzed. A mathematical model describing the cutting force of a grit and micro-crack length was established to clarify the ductile-brittle transition mechanisms of isotropic material. The model revealed that material removal mechanisms and grinding force were mainly determined by the crack equivalent length in front of the grit and its equivalent cutting force. The ground surface roughness and subsurface damage depth were mainly affected by the cutting force of the grit and length of cracks behind it. The ductile machinability of SLSG was better than that of HPFS due to the bonding of metallic atoms in SLSG with nonbridging oxygens, as well as their packing into free volume in SiO2 network. 相似文献
50.
Fancong Zeng Yingrui Sui Yanjie Wu Dongyue Jiang Zhanwu Wang Fengyou Wang Bin Yao Lili Yang 《Ceramics International》2021,47(13):18376-18384
Element doping into the Cu2ZnSn(S,Se)4 (CZTSSe) absorber is an effective method to optimize the performance of thin film solar cells. In this study, the Cu2InxZn1-xSn(S,Se)4 (CIZTSSe) precursor film was deposited by magnetron cosputtering technique using indium (In) and quaternary Cu2ZnSnS4 (CZTS) as targets. Meanwhile, the In content was controlled using the direct current (DC) power on In target (PIn). A single kesterite CIZTSSe alloy was formed by successfully doping a small number of In3+ into the main lattice of CZTSSe. The partial Zn2+ cations were substituted by In3+ ions, resulting in improving properties of CZTSSe films. Morphological analysis showed that large grain CIZTSSe films could be obtained by doping In. The well-distributed, smooth, and dense film was obtained when the PIn was 30 W. The band gap of CIZTSSe could be continuously adjusted from 1.27 to 1.05 eV as PIn increased from 0 to 40 W. In addition, the CIZTSSe alloy thin film at PIn = 30 W exhibited the best p-type conductivity with Hall mobility of 6.87 cm2V?1s?1, which is a potential material as the absorption layer of high-performance solar cells. 相似文献