Diode-HBT-logic circuits monolithically integrable with ECl/CMLcircuits

A novel logic approach, diode-HBT logic (DHL), that is implemented with GaAlAs/GaAs HBTs and Schottky diodes to provide high-density and low-power digital circuit operation is described. This logic family was realized with the same technology used to produce emitter-coupled-logic/current-mode-logic (ECL/CML) circuits. The logic operation was demonstrated with a 19-stage ring oscillator and a frequency divider. A gate delay of 160 ps was measured with 1.1 mW of power per gate. The divider worked properly up to 6 GHz. Layouts of a DHL flip-flop and divider showed that circuit area and transistor count can be reduced by about a factor of 3, relative to ECL/CML circuits. The new logic approach allows monolithic integration of high-speed ECL/CML circuits with high-density DHL circuits with high-density DHL circuits     

夜视系统鉴别率测试的新方法

用室内低光照高对比鉴别率取代野外探测目标距离作为衡量夜视系统性能优劣的标准,将给验收工作带来方便。本文给出一种实验室内测试夜视系统鉴别率的方法。文中导出了夜视系统鉴别率的一种新的表达式,从而提出了一种改进后的物理模型及其实验方案。分析表明,采用新方案,即在实验室中人为增加环境照度,由此测得的系统工作鉴别率,用以取代野外探测目标距离,其可信度可望得到明显的提高。     

Thermal fatigue effects on the temperature distribution inside IGBT modules for zone engine aeronautical applications

This work examines the thermal fatigue effects on the temperature distribution inside IGBT modules for aeronautical applications. Exactly, they are used in a very different application where temperature cycling due to the working environment is the most limiting fact. In this case, it is concluded that solder delamination does not present any restriction to module lifetime at short term (up to 60% of total delaminated area). In addition, it is proposed only determining the delaminated area behind devices, which is the main responsible of the thermal temperature increase.     

Bandwidth allocation algorithms for weighted maximum rate constrained link sharing policy

This paper addresses the problem of bandwidth allocation under the weighted maximum rate constrained link sharing policy and proves a key theory in the condition of allocation termination. We propose several algorithms with various worst-case and average-case time complexities, and evaluate their computation elapse times.     

Boundary Constrained Swept Surfaces for Modelling and Animation

Due to their simplicity and intuitiveness, swept surfaces are widely used in many surface modelling applications. In this paper, we present a versatile swept surface technique called the boundary constrained swept surfaces. The most distinct feature is its ability to satisfy boundary constraints, including the shape and tangent conditions at the boundaries of a swept surface. This permits significantly varying surfaces to be both modelled and smoothly assembled, leading to the construction of complex objects. The representation, similar to an ordinary swept surface, is analytical in nature and thus it is light in storage cost and numerically very stable to compute. We also introduce a number of useful shape manipulation tools, such as sculpting forces, to deform a surface both locally and globally. In addition to being a complementary method to the mainstream surface modelling and deformation techniques, we have found it very effective in automatically rebuilding existing complex models. Model reconstruction is arguably one of the most laborious and expensive tasks in modelling complex animated characters. We demonstrate how our technique can be used to automate this process.     

Heterogeneous object modeling: A review

A review on the recent development in heterogeneous object modeling is provided in this paper. General problems and prevalent solutions to the modeling of heterogeneous objects are investigated. Vigorous heterogeneous object representations are roughly classified into three major categories: evaluated models, unevaluated models and composite models. We reveal their similarities and study their strengths and weaknesses in terms of the representational capacities, intuitiveness, exactness, compactness, efficiency and other criteria. Different design paradigms are briefly reviewed to provide an overview of the state-of-the-art in heterogeneous object design. Finally, open problems and possible future directions are discussed.     

BOOM BOX与GM338接口电路的改进

本文针对BOOM BOX系统在使用中存在的一些问题，对BOOMBOX与GM338电台接口电路进行了分析，找出了存在的问题，并对其接口进行了改进和优化。     

High-breakdown-voltage AlSbAs/InAs n-channel field-effecttransistors

InAs channel field-effect transistors of 1-μm gate length were grown by molecular beam epitaxy and observed to operate at channel electric fields (20 kV/cm) higher than previously demonstrated and several times greater than the threshold for impact ionization in bulk InAs. Voltage gains on the order of 10 were observed with transconductances as high as 414 mS/mm and output conductances as low as 33 mS/mm. These voltage gains are comparable to those of GaAs-based devices and are the highest observed for InAs channel devices. The results demonstrate the potential for practical room-temperature operation of InAs FETs     

Traveling wave method for calculation of linewidth, frequencytuning, and stability of semiconductor lasers

The authors present a new traveling wave method for calculating the linewidth, the frequency tuning efficiency, and a mode stability parameter for a general class of laser-diode structures. The method leads to simple semianalytic expressions which allow an easy numerical determination of the three parameters     

Determination of glycyrrhizin and glycyrrhetinic acid in traditional Chinese medicinal preparations by capillary electrophoresis

A simple, rapid, accurate and reproducible capillary electrophoretic method was developed for the assay of glycyrrhizin and glycyrrhetinic acid in traditional Chinese medicinal preparations. The buffer solution used in this method was acetonitrile and 0.02 M sodium dihydrogen-phosphate solution adjusted to pH 7.5 with 0.05 M sodium hydroxide. The linear calibration range was 0.04-2.00 mg/ml (r = 0.9988) for glycyrrhizin and 0.007-0.35 mg/ml (r = 0.9985) for glycyrrhetinic acid and recoveries were 98.1-101.3% for glycyrrhizin and 98.5-101.4% for glycyrrhetinic acid. The relative standard deviations were 1.02% (n = 6) for glycyrrhizin and 0.91% (n = 6) for glycyrrhetinic acid. The content of these two acids in Glycyrrhizae Radix and Glycyrrhizae Radix-containing Chinese medicinal preparations was successfully determined within 10 min.