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61.
Leonardo Gomez Michael Canonico Meekyung Kim Pouya Hashemi Judy L. Hoyt 《Journal of Electronic Materials》2008,37(3):240-244
Ultrathin strained-Si/strained-Ge heterostructures on insulator have been fabricated using a bond and etch-back technique.
The substrate consists of a trilayer of 9 nm strained-Si/4 nm strained-Ge/3 nm strained-Si on a 400-nm-thick buried oxide.
The epitaxial trilayer structure was originally grown pseudomorphic to a relaxed Si0.5Ge0.5 layer on a donor substrate. Raman analysis of the as-grown and final transferred layer structures indicates that there is
little change in the strain in the Si and Ge layers after layer transfer. These ultrathin Si and Ge films have very high levels
of strain (∼1.8% biaxial tension and 1.4% compression, respectively), and are suitable for enhanced-mobility field-effect
transistor applications. 相似文献
62.
A method of noise variance estimation in BayesShrink image denoising is presented. The proposed approach competes with the well known MAD-based method and outperforms this method in more than 99% of our experimental results. The approach, called Residual Autocorrelation Power (RAP), provides a more accurate noise variance estimate and results in a smaller MSE. 相似文献
63.
A new unsymmetrical diamine monomer, 2,4‐diaminophenyl [4′‐(2′′,6′′‐diphenyl‐4′′‐pyridyl)phenyl]ether, was successfully synthesized by nucleophilic substitution of 1‐chloro‐2,4‐dinitrobenzene with 4‐(2′,6′‐diphenyl‐4′‐pyridyl) phenol. The diamine monomer was characterized by FTIR, 1H and 13C NMR, and elemental analysis techniques and used for the preparation of novel polyimides (PIs) by reaction with commercially available tetracarboxylic dianhydrides such as pyromellitic dianhydride, 3,3′,4,4′‐benzophenone tetracarboxylic dianhydride, and bicyclo[2.2.2]‐oct‐7‐ene‐2,3,5,6‐tetracarboxylic dianhydride. These PIs with inherent viscosities ranged from 0.43 to 0.48 dL/g were readily soluble in many organic solvents and afforded tough and flexible films by solution casting. These polymers exhibited Tgs between 237 and 294°C, and 10% weight loss temperatures in excess of 500°C with up to 56% char yield at 600°C in air. Their maximum fluorescence emission in dilute (0.2 g/dL) NMP solution appeared at 450 nm. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
64.
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66.
Saeed Zakavi Gholam Reza Karimipour Nasrin Gholami Gharab 《Catalysis communications》2009,10(4):388-390
Highly regioselective ring opening of styrene oxide with acetic acid in the presence of catalytic amounts of meso-tetra(4-CH3)phenyl- or meso-tetraphenylporphyrin at room temperature is reported. Under the same reaction conditions, cyclohexene oxide is more reactive than styrene oxide and gives the trans-isomer as the sole product. 相似文献
67.
This paper describes an experiment in the development of a small piece of software in both the languages C and C++ in a university setting. The C++ codes were found to be more modular than the corresponding C codes. Some of the other effects of C++ on program quality are very briefly discussed. The paper also discusses some of the errors that C programmers may make as novice C++ programmers, and the testing of object-oriented programs. Some of the error types possible in C++, but not in C, include delays in the flushing of output buffers and polymorphism. 相似文献
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69.
We introduce a new approach to ATM switching. We propose an ATM switch architecture which uses only a single shift-register-type buffering element to store and queue cells, and within the same (physical) queue, switches the cells by organizing them in logical queues destined for different output lines. The buffer is also a sequencer which allows flexible ordering of the cells in each logical queue to achieve any appropriate scheduling algorithm. This switch is proposed for use as the building block of large-stale multistage ATM switches because of low hardware complexity and flexibility in providing (per-VC) scheduling among the cells. The switch can also be used as scheduler/controller for RAM-based switches. The single-queue switch implements output queueing and performs full buffer sharing. The hardware complexity is low. The number of input and output lines can vary independently without affecting the switch core. The size of the buffering space can be increased simply by cascading the buffering elements 相似文献
70.
Tuned ring oscillators are used to generate multiple phases of a sinusoid for a variety of applications including phased- array transceivers and clock and data recovery circuits. A variable-phase ring oscillator (VPRO) is presented that generates outputs with a controllable phase progression, enabling its use in a compact low-power single-chip phased-array transceiver architecture. The VPRO functionality is shown to be robust with respect to process and layout mismatches. This enables the implementation of integrated phased arrays with acceptable array performance even in the absence of mismatch calibration circuitry, which are essential in other phase-shifterless schemes such as coupled oscillator arrays. A prototype 24-GHz four-channel single-chip phased-array transceiver implemented in a 0.13-mum CMOS process is presented to validate these claims. 相似文献