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71.
We have demonstrated a graded-index-rod external coupled-cavity (GRECC) laser with backface output through a partially transmitting external cavity mirror. Laser output is monitored from the backface in a transmitter module with double-loop feedback control which stabilizes output power and maintains single-frequency operation under CW and pseudorandom pulse modulation. 相似文献
72.
73.
J. J. Liou K. Lee S. M. Knapp K. B. Sundaram J. S. Yuan D. C. Malocha M. Belkerdid 《Solid-state electronics》1990,33(12):1629-1632
The quasi-static approximation, which assumes that free-carrier propagation delay in the semiconductor device is zero, is often used in device modeling. Consequently, the quasi-static model is adequate only for low-frequency excitations for which free-carrier propagation delay is very small compared to the variation of the excitations. This paper develops a non-quasi-static model suitable for metal-semiconductor junction diodes subjected to small-signal excitation. We show that the predictions of the non-quasi-static model agree more favourably with experimental data taken from Al---Si diodes than that of the quasi-static model, particularly when the frequency of the excitation is high. 相似文献
74.
Wu W.-C. Chao T.-S. Peng W.-C. Yang W.-L. Wang J.-C. Chen J.-H. Lai C.-S. Yang T.-Y. Lee C.-H. Hsieh T.-M. Liou J. C. 《Electron Device Letters, IEEE》2007,28(3):214-216
In this letter, high-performance and reliable wrapped select gate (WSG) polysilicon-oxide-nitride-oxide-silicon (SONOS) memory cells with multilevel and 2-bit/cell operation have been successfully demonstrated. The multilevel storage is easily obtained with fast program/erase speed (10 mus/5 ms) and low programming current (3.5 muA) for our WSG SONOS by a source-side injection. Besides the excellent reliability properties of our multilevel WSG-SONOS memory including unconsidered gate and drain disturbance, long charge retention (>150degC) and good endurance (>104) are also presented. This novel WSG-SONOS memory with a multilevel and 2-bit/cell operation can be used in future high-density and high-performance memory application 相似文献
75.
A model of reverse base current characteristics which is based on device physics is presented. The model requires only physical parameters, thus allowing circuit designers to estimate the device performance under avalanche operation prior to the actual device fabrication. Previously reported experimental data are included in support of the model 相似文献
76.
Surface area-normalized rate constants (k(SA)) of reaction between metallic nanoparticles and reducible contaminants, such as chlorinated hydrocarbons, heavy metals, and nitrate, have been reported to be dramatically increased as compared to that of commercial metallic powder. However, k(SA) for individual pollutants in previously published data vary by as much as 1-2 orders of magnitude and much of this variability is due to the effect of various sizes. The size dependence of the reactivity of nanoparticles is not yet fully understood; however, yielding nanoparticles with uniform size and without agglomeration during the period of reaction would demonstrate the effect of varying particle size. In this study, resin-supported zerovalent copper with average particle size of 7, 10, 18, 26, and 29, respectively, were successfully synthesized and evidenced no agglomeration during the reaction period of 10h. The k(SA) of copper nanoparticles (k(n,SA)) was 110-120 times higher than that of powdered copper particles (k(p,SA)) when the copper particle size was about 10nm. However, for diameters of 18-29 nm, the ratio of k(n,SA)/k(p,SA) was around 10-20, indicating that the reactivity of small copper nanoparticles (approximately 10nm) varies discontinuously. Thus, most variability in previous k(SA) is attributed to the presence of small nanoparticles. 相似文献
77.
Tarak Amine Joseph W. Newkirk Hussam El-Din F. El-Sheikh Frank Liou 《The International Journal of Advanced Manufacturing Technology》2014,73(9-12):1427-1435
Several techniques can be used to improve surface properties of metals. These can involve changes on the surface chemical composition such as alloying or on the surface microstructure, such as hardening. In the present work, melting of the surface by a 9 kW CO2 CW laser of wavelength 10.6 μm was used to alter surface features of D2 tool steel. Carbon powder and nitrogen gas were used as sources of alloying elements during laser processing. The effect of various laser parameters (power and speed) on the microstructure and hardness of D2 tool steel was investigated. Laser powers from 1 to 8 kW and laser speeds from 5 to 15 mm/s were employed. It was found that as the laser power increases, the hardness of the melted zone decreases while that of the heat-affected zone increases. On the other hand, the depth of both of melted and heat-affected zones increases with power. 相似文献
78.
刘重轩 《纺织高校基础科学学报》1997,10(1):42-45
箱式组合变电站箱内温的特点跟负载特性及箱壳的散热结构有关,而变电站内的电力变压器的负载率又跟箱内温升及箱壳的散热等级有关,本文给出了变压器负载率的计算公式和参考值。 相似文献
79.
Sivertsen K.N. Liou A.E.-L. Emami-Forooshani A. Michelson D.G. 《Wireless Communications, IEEE Transactions on》2009,8(8):3921-3925
We show by simulation that when the fading signals observed on orthogonally polarized diversity branches follow Ricean statistics, the distribution of polarization states on the Poincar′e sphere is well-approximated by a Fisher distribution. Further, we show that the Fisher concentration parameter is: (1) completely determined by the corresponding Ricean Kfactors and the cross-correlation coefficient between the diversity branches, both of which can be estimated from simple measurements of received power vs. time, and (2) a good indicator of the level of cross-polar discrimination (XPD) on the channel. The insights gained are potentially useful to those engaged in the development and validation of schemes that use either polarization re-use or polarized MIMO. 相似文献
80.
Dr. Hsueh‐Yun Lee Dr. Chia‐Ron Yang Dr. Mei‐Jung Lai Han‐Li Huang Yi‐Ling Hsieh Yi‐Min Liu Dr. Teng‐Kuang Yeh Yu‐Hsuan Li Samir Mehndiratta Dr. Che‐Ming Teng Dr. Jing‐Ping Liou 《Chembiochem : a European journal of chemical biology》2013,14(10):1248-1254
A series of 1‐arylsulfonyl‐5‐(N‐hydroxyacrylamide)indolines ( 7 – 15 ) has been developed; the compounds exhibited potent histone deacetylase (HDAC) inhibitory activities. Notably, almost all of this series exhibited better HDAC‐inhibitory and antiproliferative activities than 3‐(1‐benzenesulfonyl‐1H‐indol‐5‐yl)‐N‐hydroxyacrylamide ( 6 ), as reported in a previous study. Among these compounds, 3‐[1‐(4‐methoxybenzenesulfonyl)‐2,3‐dihydro‐1H‐indol‐5‐yl]‐N‐hydroxyacrylamide ( 9 ) showed a two‐ to tenfold increase in activity compared to SAHA ( 1 ) in the suppression of lipopolysaccharide‐induced cytokine production. Compound 9 also caused a marked reduction in carrageenan‐induced acute inflammation in a rat model. Taken together, these data indicated that 1‐arylsulfonyl‐5‐(N‐hydroxyacrylamide)indolines HDAC inhibitors exhibit potent anti‐inflammatory activity. 相似文献