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21.
A new type of high temperature energy storage material was obtained through the melt infiltration method, using compounding SiC ceramic foam as matrix and Na2SO4 as phase change material. The resulting composite material was measured by XRD, SEM, TG-DSC methods. The experimental results indicate that the composite is composed of silicon carbide, sodium sulfate and square quartz, and no chemical reactions occurs between Na2SO4 and SiC matrix. Na2SO4 has a good bonding with the SiC ceramic foam matrix. As the composite material is characterized by high thermal energy storage density and high thermal conductivity, it is suit for energy storage under high temperature. Funded by the “863” Hi-Tech Research and Development Program of China (2008AA05Z418)  相似文献   
22.
苏州50后著名女作家范小青和70后新生代女作家朱文颖的小说创作,在传承和新变苏州文化方面表现出较为鲜明的特点。从其创作内容和创作风格的简略对比中可以看出,新老苏州作家根植地域、融合地域、挖掘地域的创作空间可谓至为广阔。  相似文献   
23.
高职学院经过合并升格后,既面临机遇也面临挑战,全面整合高职学院的各种资源,需要厘清整合的涵义和特征,把握整合的内容,从精神引领、利益调整、文化整合等途径探寻有效的整合之道。  相似文献   
24.
Xia  Bin  Bai  Yuxuan  Yin  Junjie  Li  Yun  Xu  Jian 《Information Systems Frontiers》2021,23(2):285-298
Information Systems Frontiers - System logs that trace system states and record valuable events comprise a significant component of any computer system in our daily life. Each log contains...  相似文献   
25.
Jia  Wei  Gao  Jian  Xia  Wei  Zhao  Yang  Min  Hai  Lu  Jing-Ting 《国际自动化与计算杂志》2021,18(1):18-44

Palmprint recognition and palm vein recognition are two emerging biometrics technologies. In the past two decades, many traditional methods have been proposed for palmprint recognition and palm vein recognition, and have achieved impressive results. However, the research on deep learning-based palmprint recognition and palm vein recognition is still very preliminary. In this paper, in order to investigate the problem of deep learning based 2D and 3D palmprint recognition and palm vein recognition in-depth, we conduct performance evaluation of seventeen representative and classic convolutional neural networks (CNNs) on one 3D palmprint database, five 2D palmprint databases and two palm vein databases. A lot of experiments have been carried out in the conditions of different network structures, different learning rates, and different numbers of network layers. We have also conducted experiments on both separate data mode and mixed data mode. Experimental results show that these classic CNNs can achieve promising recognition results, and the recognition performance of recently proposed CNNs is better. Particularly, among classic CNNs, one of the recently proposed classic CNNs, i.e., EfficientNet achieves the best recognition accuracy. However, the recognition performance of classic CNNs is still slightly worse than that of some traditional recognition methods.

  相似文献   
26.
International Journal of Control, Automation and Systems - An underwater gliding snake-like robot (UGSR) combines the advantages of an underwater glider (UG) and an underwater snake-like robot...  相似文献   
27.
复合材料层合板损伤模型中的刚度退化需要通过损伤变量来实现。针对通常采用的2种损伤变量定义,给出了统一表达式。此外,损伤刚度矩阵是损伤变量的函数,基于应变等效假设推导了三维损伤刚度矩阵,从而避免了对损伤刚度矩阵的人为假定。最后,通过复合材料层合板在冲击载荷作用下的数值模拟,讨论了损伤变量的2种定义对数值结果的影响,表明损伤变量的不同定义对分层和基体损伤分布存在一定的影响,对冲击载荷的影响不大。建议在复合材料损伤模拟中,应予关注损伤变量。  相似文献   
28.
Based on some assumptions, the dynamic analysis model of anchorage system is established. The dynamic governing equation is expressed as finite difference format and programmed by using MATLAB language. Compared with theoretical method, the finite difference method has been verified to be feasible by a case study. It is found that under seismic loading, the dynamic response of anchorage system is synchronously fluctuated with the seismic vibration. The change of displacement amplitude of material points is slight, and comparatively speaking, the displacement amplitude of the outside point is a little larger than that of the inside point, which shows amplification effect of surface. While the axial force amplitude transforms considerably from the inside to the outside. It increases first and reaches the peak value in the intersection between the anchoring section and free section, then decreases slowly in the free section. When considering damping effect of anchorage system, the finite difference method can reflect the time attenuation characteristic better, and the calculating result would be safer and more reasonable than the dynamic steady-state theoretical method. What is more, the finite difference method can be applied to the dynamic response analysis of harmonic and seismic random vibration for all kinds of anchor, and hence has a broad application prospect.  相似文献   
29.
导磁体在汽车零件感应加热中的应用技术   总被引:1,自引:2,他引:1  
本文简单介绍了导磁体工作的基本原理,并给出在汽车零件大规模生产中所积累的导磁体应用的一些经验,以阐明如何更有效地使用导磁体。  相似文献   
30.
The oxidation behavior and mechanism of aluminum oxynitride (AlON) powder exposed to air at elevated temperatures between 800°C and 1300°C was investigated by X-ray diffractometry (XRD), scanning electron microscope (SEM), electron spin resonance (ESR), nuclear magnetic resonance (NMR), and simultaneous thermogravimetry, differential thermal analysis, and mass spectrometry techniques (TG-DTA-MS). The weight of AlON gradually increases to a maximum value at 1150°C and then decreases with further heating. Meanwhile, AlON powder undergoes chemical changes, as evidenced by lattice expansion, and turns eventually into alumina. ESR spectra reveal the occurrence of lone pair electrons in the oxidized products and the intensity of corresponding resonance signal increases before disappearing with the increase in temperature. Combined with the results of NMR and TG-DTA-MS, the measured data suggest that Al-N in [AlO3N] tetrahedron and [AlO5N] octahedron are gradually oxidized into Al-O-N group with lone pair electrons, which causes continuous weight gain and lattice expansion. Further oxidation at higher temperatures results in alumina and N2.  相似文献   
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