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31.
32.
Kollipara R.T. Arodzero A. Bashindzhagyan G. Brau J.E. Frey R. Gao D. Mason D. Sinev N. Strom D. Yang X. 《IEEE transactions on nuclear science》1995,42(2):92-101
The SSC GEM silicon Central Tracker design incorporated 18-cm long single-sided AC-coupled silicon microstrip ladders. Compared to the 12-cm long ladders considered in the preliminary stages of the tracker design, the 18-cm long ladders have the advantage of reduced cost, channel count and overall power consumption, and led to a simplified tracker assembly. However, such long ships also present the challenge of maintaining satisfactory performance. The increased capacitance and series resistance contribute to lower signal-to-noise ratios, longer time walk, higher power consumption per channel and increased probability of crosstalk to neighboring channels. In this paper, an accurate method to calculate the geometric capacitance of the AC-coupled microstrips is presented and the calculated results are compared with measurements, SPICE simulations are performed to predict the noise, the extent of interstrip capacitive coupling and the dispersion of the detector signal due to the finite series resistance of the metal strips and the long length of the detector. The influence of the preamplifier current and the shaping time on the signal and noise levels is also presented. The study concludes that the 18-cm long ladders can successfully satisfy the performance goals of the GEM silicon Central Tracker 相似文献
33.
Ku T.K. Chen S.H. Yang C.D. She N.J. Wang C.C. Chen C.F. Hsieh I.J. Cheng H.C. 《Electron Device Letters, IEEE》1996,17(5):208-210
Undoped and phosphorus (P)-doped diamond-clad Si field emitter arrays have been successfully fabricated using microwave plasma chemical vapor deposition (MPCVD) technology. The electron emission from the blunt diamond-clad microtips are much higher than those for the pure Si tips with sharp curvature due to a lower work function. Furthermore, the characteristics of emission current against applied voltage for the P-doped diamond-clad tips show superior emission at lower field to the undoped ones. After the examination of Auger electron spectroscopy (AES) and electrical characteristics of as-grown diamond, such a significant enhancement of the electron emission from the P-doped diamond-clad tips is attributed to a higher electron conductivity and defect densities 相似文献
34.
在内蒙古大青山地区发育一套高温区域变质岩──麻粒岩,在这高温变质岩内有一系列的糜棱岩带.通过对糜棱岩带中石英的研究,对比深部地壳与浅部地壳石英的变形特点,获得一些新的认识.对石英显微构造、动态重结晶、TEM研究及石英岩组学方面进行了研究,发现石英的塑性变形显著,以缎带石英产出,发育各种塑性变形的显微构造,变形带、波状消光和亚颗粒显著:TEM观察到石英中有直线状的位错.岩组学研究显示出石英高温变形和多期构造叠加的特点. 相似文献
35.
In this paper, we propose a new definition of digital connectivity for gray images on a 2D space for arbitrary grid systems. We extend a digital version of the Jordan curve theorem and its converse proved earlier by Rosenfeld for the rectangular grid system. We also extend in two directions the concept of well-composed sets introduced by Lateckiet al.(1995,Comput. Vision Image Understanding61,70–83). First, we extend the definition of well-composed sets from the quadratic grid system to an arbitrary grid system. Then, by using the concept of parameter-dependent connected components introduced by us in a previous work, we allow the pixels in a connected component of a well-composed set to have different gray values so that the connectivity of connected components accommodates a wider meaning. 相似文献
36.
本文介绍了以微处理器与IBM-PC上的彩色/图形适配器相结合构成的一种智能显示系统。本系统主要解决数控系统中主CPU与6845CRTC争夺显示缓存的矛盾。保证了6845CRTC对显示缓存操作的时间要求;并且保证了数控系统中主CPU对显示缓存操作的随意性。 相似文献
37.
In this paper, we investigate the problem of determining the optimal bandwidth allocation for a Dynamic Bandwidth Allocation Scheme (DBAS). The objective is to minimize the total amount of bandwidth required to satisfy the Quality of Service (QoS) requirements of all traffic streams. It is shown that when the performance functions satisfy a certain number of conditions, there exists a unique optimal bandwidth allocation such that, for each traffic stream, either its QoS is just satisfied or its QoS is over-satisfied and it is allocated zero bandwidth. Such an allocation is said to be efficient. It is also shown that there exists a unique efficient allocation in the entire feasible region. An iterative algorithm is developed to compute the efficient allocation employing its special properties. Numerical examples are presented to demonstrate how the algorithm works. Future extensions of this work are also discussed.Partially supported by NSERC of Canada through grants OGP14020 and STRIN-200. 相似文献
38.
Z. -G. Fan Y. -X. Zhuang G. Yang R. Shao G. -F. Zhang 《Journal of Alloys and Compounds》1993,200(1-2):33-36
The oxygen absorption process in highly aligned YBa2Cu3Ox samples in air and in pure oxygen was studied at several constant temperatures. The process can be expressed in two steps, a chemical reaction controlled step and a diffusion controlled step. The kinetic equations are as follows respectively:
(1 − at) ln(1 − at) + at = kDt
The activation energy was calculated using an Arrhenius equation. The technical conditions of heat treatment for oxygen absorption of highly aligned YBa2Cu3Ox crystals are discussed. 相似文献
39.
本文总结了近年冶金炉渣氮酸盐容量的研究方法,氮在炉渣中存在形态与炉渣氧分压的关系,炉渣氮化物容量与温度及炉渣成分的关系,并给出设计钢液脱氮渣系的基本原则。 相似文献
40.
A technique for SiO2 formation by liquid-phase deposition (LPD) at nearly room temperature for low-temperature processed (LTP) polysilicon thin-film transistor (poly-Si TFT) was developed. LPD SiO2 film with a lower P-etch rate shows a dense structure. LPD SiO2 also exhibits good electrical characteristics. LTP poly-Si thin-film transistors (TFTs) with LPD SiO 2 as the gate insulator have been fabricated and investigated. Their characteristics indicate performance adequate for their use as pixel transistors in liquid crystal displays (LCDs) 相似文献