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61.
62.
降低陶瓷材料表面电荷的积累一直是俄歇分析技术能否成功应用于该类材料必须解决的首要问题. 通过实验认为:陶瓷材料试样减薄法可以用来降低表面电荷.采用这种方法,样品可分析区域大小仅依赖于电子束斑尺寸. 因而,用Microlab 310--F热场发射扫描俄歇微探针分析仪能在几十纳米的微区内,获取结构信息和除氢氦外的化学成分信息,突破了陶瓷材料在低电压、低电流下约几十微米的分析范围. 在此基础上,挑选了掺Dy的α-Sialon ,掺Y、La的α-Si3N4与以Al2O3为基体加入SiC晶须, 并通氮气氛处理的三种高性能陶瓷作为实验对象,分析和研究它们的晶粒、界面的成份、化学态和结构.发现α-Si3N4和α-Sialon陶瓷中的Si(LVV, KLL)峰位都会向低能端漂移,峰位分别为: 84eV 和1613eV. Si--N--O的结合态又使Si(LVV)峰继续漂移到80eV左右. 掺Y、La的α-Si3N4的玻璃相区, Si至少以两种或者两种以上的化学态存在.掺Dy的α-Sialon陶瓷的局部区域内有四种组分不同的固溶相及三种组分不同的晶间相. 另外, 在SiC与SiC-BN-C纤维补强复合陶瓷材料的断裂面,观察到从SiC基体拔出的纤维表面的大部分是残留的C层与C-BN交界层. 相似文献
63.
We demonstrate that a scanning acoustic microscope (SAM) operating in the frequency range 100–400 MHz can detect cracks at the aggregate/paste interface and subsurface cracks in aggregates with high sensitivity. A complete interpretation of the obtained results has been made by combining high and low frequency acoustic microscopy, SEM, optical microscopy, and energy dispersive (X-ray) spectroscopy. 相似文献
64.
Kenji Kinashi Hironori ShinkaiWataru Sakai Naoto Tsutsumi 《Organic Electronics》2013,14(11):2987-2993
Photorefractive (PR) performances of methyl-substituted poly(triarylamine) (PTAA)-based PR device were demonstrated using chemically modified electrodes (CMEs) of self-assembled monolayer (SAM) coated indium-tin-oxide (ITO) electrodes. The SAM-ITO electrodes successfully suppressed dark current which blocks the formation of space-charge field and also causes the dielectric breakdown. The PR device consisted of composite of PTAA, 4-azacycloheptylbenzylidenemalononitrile (7-DCST), N-ethylcarbazole (ECz), and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) sandwiched between the SAM-ITO electrodes. The PR devices showed the PR performances: optical gain Γ, refractive index Δn, diffraction efficiency η, response time τ, sensitivity S, phase shift Φ, trap-limited field Eq, number density of traps NT, and space-charge field ESC. The remarkable response time of 11.3 ms was achieved at the low electric field of 20 V μm−1, which was comparable to the response time of high-definition television (HDTV) quality of 16 ms. Our approach will widen the usage of higher mobility materials to photorefractive field and give us more favorable materials to achieve the best performance of photorefractivity in the future. 相似文献
65.
由于技术资金的限制,我国中小型煤矿在瓦斯监测体系建设上存在诸多问题。为了破解这些难题,面向中小型煤矿的实际应用设计了一种基于单片机AT91SAM9261的小型瓦斯智能监控系统。整个设计具有简单实用、便于在现有设备技术上升级改造的特点,具有一定的应用前景。 相似文献
66.
P. AnsorenaAuthor Vitae A. ZuzuarreguiAuthor VitaeE. Pérez-LorenzoAuthor Vitae M. MujikaAuthor VitaeS. AranaAuthor Vitae 《Sensors and actuators. B, Chemical》2011,155(2):667-672
One of the most remarkable procedures to immobilize some biological molecules onto surfaces is the use of self-assembled monolayers (SAMs). The aim of this work is to analyse the influence of formation conditions in the detection capability of two different SAMs. With this purpose two techniques have been implemented: the Quartz Crystal Microbalance with Dissipation (QCM-D) and the Surface Plasmon Resonance (SPR). Thus, several parameters usually involved in the SAM protocols have been characterized, i.e. the nature of the thiolated acid. The influence of its concentration and incubation time has been also taken into account. For the validation of these biological layers, the polymyxin B sulfate salt (PmB), as ligand, and the lipopolysaccharide (LPS), as analyte, have been used. It is demonstrated that both in the QCM and the SPR, the use of SAM improves significantly the detection and immobilization of the target compound and an optimum SAM formation protocol is provided. 相似文献
67.
68.
Volatile organic contamination is known to be one of the factors to cause the failure of head-disk interface (HDI). Therefore, reduction of its harmful effects and improvement of the stability and reliability of HDI is becoming an important issue. In this study, the effects of some model compounds of volatile organic contamination on the tribological characteristics of HDI were systematically investigated using a contact start/stop (CSS) tester. The slider surface after the CSS tests was analyzed using Time-of-Flight Secondary Ion Mass Spectroscopy (TOF-SIMS). Transfer of lubricating oil onto the slider surface was detected after the CSS tests. The organic contaminants promoted the transfer and resulted in high and unstable friction force. Fluorinated self-assembled monolayers (SAMs) were applied on the slider surface for reducing the transferred amount of the lubricating oil. Tribological performance of the slider coated with the SAMs and the transfer amount of lubricating oil onto the slider surface in the presence of contaminant was investigated. The friction force was low and stable in the case of the SAMs coated slider even under environmental contaminant. This result could be explained by the reduction of the transferred lubricating oil because the SAMs that coated on the slider surface were low surface energy. 相似文献
69.
70.
提出了基于稀疏表示的声扫描显微镜(Scanningacousticmicroscope,SAM)图像超分辨率重构方法,以解决其空间检测分辨率受超声波频率和穿透深度的限制,原始SAM图像分辨率较低,不利于封装缺陷辨识等问题。通过字典设计训练和稀疏系数α求解获得了重构的高分辨率SAM图像,利用Levenberg-Marquardt算法改进BP神经网络(LM-BP),并用于倒装芯片焊点缺陷识别。与原始图像及双三次插值图像相比,稀疏重构图像的峰值信噪比明显增大,提高了SAM图像质量,减小了芯片焊点的错误识别数目,错误率降至2.76%。试验结果表明稀疏表示的SAM重构算法和LM-BP神经网络训练速度快、识别精度高,可用于高密度半导体封装缺陷的检测及可靠性评估。 相似文献