反向阳光间被动式太阳能空气采暖系统

介绍一种多层建筑中反向阳光间被动式太阳能空气采暖系统。它通过置于屋顶和地面的风管实现公寓中南部阳光间的太阳能得热向北部阳光间的自然传递。南部阳光间受热的空气上升，进入置于屋顶的风管，并通过这些风管流向北部阳光间；同时，南部阳光间置换出的空气被由北部阳光间的通过置于地面风管流向南部阳光间的较冷的空气所代替。由于系统还可用于东西阳光间之间，建筑物不受相对于太阳朝向的限制。     

Strange chaotic attractor crowding in boost converter model

A set of chaotic attractors is observed on a boost converter model. The union of their Poincare maps is strange. The attractors are densely packed such that they are sensitive to initial conditions. However every attractor in the set is stable with a finite (may be long) period     

Simulation and design methodology for a 50-Gb/s multiplexer/demultiplexer package

A 50 Gb/s package for SiGe BiCMOS 4:1 multiplexer and 1:4 demultiplexer targeting SONET OC-768 serial communication systems is introduced in this work. The package was designed to facilitate bit-error-rate tests and constructed with high-speed coaxial connectors, transmission lines on ceramic substrate, ribbon bonds for chip-to-package interconnects, and a metal composite housing. Numerical simulations were conducted to guide the package design, and both small signal measurements and operational tests were performed thereafter to verify the design and modeling concepts. To keep the model structure under the existing computing capability, the simulation was segmented into three sections - coaxial connector to transmission line, transmission line alone, and transmission line to ribbon bond, and then the results were assembled to predict the performance of the entire package. The package was operated up to 50 Gb/s with low degradation to input digital waveforms and free of error.     

Cisco SRP与以太网的第二层互通方式

在扩展以太网协议用于城域或广域组网的过程中，暴露出了传统的以太网树型或星型拓扑缺乏有效的性能监视和保护倒换协议的弱点，网络的维护也比较复杂，在传输骨干上使用环形拓扑有助于解决这个问题。Cisco SRP是一种基于双纤环型拓扑的媒体访问协议，主要应用于城域或广域的传输骨干环上，本文提出了以太网和CiscoSRP骨干环之间在第二层上互通的两种方式，并分析了两种互通方式实现中的一些具体问题。     

CO_2激光对兔脑组织血脑屏障的影响

同等功率和照射时间条件下,在14只家兔大脑皮质运用伊文思蓝染料和超微结构观察方法进行血脑屏障改变的研究。结果表明:CO_2激光作用十分表浅,且激光作用后的水肿层血脑屏障改变是可逆的。     

Ca原子的Penning离化

用614.3nm染料激光照射以Ne为缓冲气体的Ca空心阴极灯,观察到了Ca原子的Pen-ning离化效应。对比在Li空心阴极灯中获得的光电流信号,解释了Ca原子的彭宁离化。     

自适应相位制中波同步广播及现场试验

在本试验中，采用智能同步广播激励器和ＣＣＴＶ传输的１ＭＨｚ标频，实现了中波同步广播同频保护率趋于０ｄＢ．并提出了自适应相位跟踪同步的概念。     

Enhancement of oxide break-up by implantation of fluorine inpoly-Si emitter contacted p+-n shallow junctionformation

In this study, it is demonstrated that the incorporation of fluorine can enhance poly-Si/Si interfacial oxide break-up in the poly-Si emitter contacted p⁺-n shallow junction formation. The annealing temperature for breaking up the poly-Si/Si interfacial oxide has been found to be as low as 900°C. As a result, the junction depth of the BF₂-implanted device is much larger than that of the boron-implanted device     

Performance analysis of adaptive interleaving for OFDM systems

We proposed a novel interleaving technique for orthogonal frequency division multiplexing (OFDM), namely adaptive interleaving, which can break the bursty channel errors more effectively than traditional block interleaving. The technique rearranges the symbols according to instantaneous channel state information of the OFDM subcarriers so as to reduce or minimize the bit error rate (BER) of each OFDM frame. It is well suited to OFDM systems because the channel state information (CSI) values of the whole frame could be estimated at once when transmitted symbols are framed in the frequency dimension. Extensive simulations show that the proposed scheme can greatly improve the performance of the coded modulation systems utilizing block interleaving. Furthermore, we show that the adaptive interleaving out performs any other static interleaving schemes, even in the fast fading channel (with independent fading between symbols). We derived a semi-analytical bound for the BER of the adaptive interleaving scheme under correlated Rayleigh fading channels. Furthermore, we discussed the transmitter-receiver (interleaving pattern) synchronization problem     

Pd-Ge contact to n-GaAs with the TiW diffusion barrier

Pd-Ge based ohmic contact to n-GaAs with a TiW diffusion barrier was investigated. Electrical analysis as well as Auger electron spectroscopy and the scanning electron microscopy were used to study the contact after it was subjected to different furnace and rapid thermal annealing and different aging steps. All analyses show that TiW can act as a good barrier metal for the Au/Ge/Pd/n-GaAs contact system. A value of 1.45 × 10⁻⁶ Ω-cm² for the specific contact resistance was obtained for the Au/TiW/Ge/Pd/n-GaAs contact after it was rapid thermally annealed at 425°C for 90 s. It can withstand a thermal aging at 350°C for 40 h with its ρ_c increasing to 2.94 × 10⁻⁶Ω-cm² and for an aging at 410°C for 40 h with its ρ_c increasing to 1.38 × 10⁻⁵ Ω-cm².