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1.
Chun-Tsen Lu Kun-Wei Lin Huey-Ing Chen Hung-Ming Chuang Chun-Yuan Chen Wen-Chau Liu 《Electron Device Letters, IEEE》2003,24(6):390-392
A new and interesting Pd-oxide-Al/sub 0.3/Ga/sub 0.7/As MOS hydrogen sensor has been fabricated and studied. The steady-state and transient responses with different hydrogen concentrations has been measured at various temperatures. Based on the large Schottky barrier height and presence of oxide layer, the studied device exhibits a high hydrogen detection sensitivity and wide temperature operating regime. The studied device exhibits the low-leakage current and obvious current changes when exposed to hydrogen-contained gas. Even at room temperature, a very high hydrogen detection sensitivity of 155.9 is obtained when a 9090 ppm H/sub 2//air gas is introduced. Furthermore, when exposed to hydrogen-contained gas at 95/spl deg/C, both the forward and reverse currents are substantially increased with increased hydrogen concentration. In other words, the studied device can be used as a hydrogen sensor under the applied bidirectional bias. Under the applied voltage of 0.35 V and 9090 ppm H/sub 2//air hydrogen ambient, a fast adsorption response time about 10 s is found. The transient and steady-state characteristics of hydrogen adsorption are also investigated. 相似文献
2.
对己二腈工业反应器提出了两釜串联带回流的模型,通过模拟计算得出模型的级间返混系数 f=6的结论。该模型能较好地预测工业反应器中物料组分浓度变化和气、液两相的流动特性;指出了现工业反应器的鼓泡中和段体积偏小是造成己二酸浓度偏高的关键;提出了可以通过增加串连一个鼓泡预反应段的改造方案,能有效地降低己二酸的浓度,从7%降至4%左右,从而能较好地减缓腐蚀和结焦。 相似文献
3.
The results of study of the effects of yttria stabilization (0–6 mol.%) on the room-temperature fracture behavior and toughening mechanisms in zirconia-reinforced MoSi2 are presented in this paper. Transformation toughening is shown to occur only in composites reinforced with zirconia particles stabilized with 2 mol.% yttria. However, the fracture toughness levels are comparable in the other composites with yttria levels between 0 and 6 mol.%. Toughening in the other composites is attributed to the combined effects of residual stress, microcrack shielding/anti-shielding and/or crack deflection. A rigorous micromechanics-based model is presented for the estimation of residual stress levels in brittle materials reinforced with phases that can transform during cooling or under stress. The model is applied successfully to the rationalization of the observed fracture and toughening phenomena. 相似文献
4.
Jing Wang Walker D.M. Xiang Lu Majhi A. Kruseman B. Gronthoud G. Villagra L.E. van de Wiel P.J.A. Eichenberger S. 《Design & Test of Computers, IEEE》2007,24(3):226-234
Excessive power supply noise during test can cause overkill. This article discusses two models for supply noise in delay testing and their application to test compaction. The proposed noise models avoid complicated power network analysis, making them much faster than existing power noise analysis tools. can cause performance degradation and 相似文献
5.
A jet-printed digital-lithographic method, in place of conventional photolithography, was used to fabricate 64 /spl times/ 64 pixel (300 /spl mu/m pitch) matrix addressing thin-film transistor (TFT) arrays. The average hydrogenated amorphous silicon TFT device within an array had a threshold voltage of /spl sim/3.5 V, carrier mobility of 0.7 cm/sup 2//V/spl middot/s, subthreshold slope of 0.76 V/decade, and an on/off ratio of 10/sup 8/. 相似文献
6.
Zhen-Qiu Lu Yan-Yun Zhang 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》1996,43(2):296-302
Reconstruction algorithms and their numerical examples of acoustical tomography based on the second-order Born transform perturbation approximation are presented. The reconstruction algorithms in the second-order Born approximation are similar in form to those in the first-order Born approximation. Replacing the angular spectrum of the scattered wave in the first-order case by the result of applying a first-order operator to the angular spectrum of the scattered wave or applying a second-order operator to the angular spectrum of the incident wave leads to the second-order reconstruction algorithms. Also, comparisons of reconstruction algorithms of the first- and second-order Born approximations are given, and they show that the second-order Born approximation algorithms have a distinct advantage over the first-order approximations in many cases 相似文献
7.
The effect of the atomic mobility on a film surface has been studied by using a three-dimensional atomistic thin-film deposition model which simulates three-dimensional thin-film images, surface profiles and cross-sectional area pictures. In addition, quantitative results of surface RMS roughness, average film thickness, atomic coordination number and its distribution, and solid fraction of the deposited thin films, were obtained from the simulations. When the film surface mobility increased from 0.3 to 3.0, RMS roughness decreased from 6.5 to 1.1, solid fraction increased from 0.27 to 0.56 and average film thickness decreased from 40 to 28, due to the reduction of the voids within the film. The full-width half magnitude of the atomic coordination distribution became narrower indicating the increased degree of crystallization. With increase in surface mobility crossing the boundary to 1.5, the film evolved from a porous or loose columnar structure with voids, to a densely packed fibrous grain structure which can be categorized by the zone structure models. 相似文献
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