结构设计应注意的若干问题

指出与荷载有关的一些问题,阐述了"半地下室"结构设计计算应注意的一些事项,指出采用morgain计算工具进行基础计算的常见错误,分析了剪力墙布置和结构构件设计中存在的一些问题,并提出相应处理办法,供设计人员参考。     

The Spatial Color Mixing Model of Digital Camouflage Pattern

A spatial color-mixing model based on tricolor angular frequencies is proposed in consideration that the design theory falls behind the application of digital camouflage pattern. The model is based on Fourier transform and Gaussian low-pass filter （LPF）. In the model, the tricolor angular frequencies are introduced to the spatial frequency response function of human color vision, and the effects of atmospheric attenuation and air screen brightness on color mixture are considered. The field test shows that the model can simulate the color-mixing process in the aspects of color-mixing order, and shape and position of color-mixing improved by optimizing the atmospheric parameters and tricolor cut-off digital camouflage pattern. spot. But the color-mixing spot color is not perfect, which can be angular frequencies. The model provides a tool for the research on     

串行通信服务器中的自适应以太网设计

串行通信服务器中的自适应快速以太网,其硬件包括运行操作系统及应用程序的MPC860T主处理器电路及其外围电路.快速以太网接口电路,负责以太网数据的收发.串行通道电路又分,负责配置监控服务器的SMC接口和负责4个HDLC数据收发功能电路.4个HDLC通道提供符合RS-232C和RS-422标准的接口.     

Price-based congestion control and local channel-link assignment for multi-radio wireless mesh networks

In multi-radio multi-channel wireless mesh networks, engineering the network capacity requires a complex cross-layer design. In this paper, in order to make the complex problem implementable in a distributed manner, we make a decoupling approach that breaks down the entire design space into routing and initial channel assignment, and distributed congestion control and local channel reassignment. We propose a unified priced-based framework for distributed congestion control and localized channel-link assignment algorithms. We demonstrate the convergence of the proposed algorithms with respect to different fairness objectives (i.e., proportional fairness and max–min fairness) via simulation on both grid and random topologies. The proposed algorithms achieve faster convergence with less overhead in the control and forwarding plane than previous multi-path based algorithms.     

Polystyrenes in channels

Polystyrenes (PS) with various stereosequences have been modeled in narrow cylindrical channels corresponding to those found in polymer-inclusion compounds (ICs), such as those formed with host cyclodextrins (CDs), where the polymers reside as guests. Isotactic (i) PS is found to fit in channels with narrower diameters (D) than syndiotactic (s) PS, when both adopt conformations permitted by the Yoon, Sundararajan, Flory RIS conformational model of PSs, while atactic (a) PS can be included in channels with D intermediate to those for i- and s-PS. In ICs formed with host γ-CD and guest a-PS homopolymer and guest poly(?-caprolactone) (PCL)-b-a-PS diblock copolymer it was observed that the a-PS homopolymer and the a-PS copolymer blocks were and were not included, respectively. Thus, it appears that a-PS is barely able to be threaded by γ-CD, whose internal diameter is ∼8 Å. Because the channel conformers found for i- and s-PS have smaller and larger diameters, respectively, than those found for a-PS, we would expect i-PS to be complexed by γ-CD, while s-PS might not. As a consequence IC formation with γ-CD may provide a means to physically separate the stereoregular forms of polystyrene. In addition, only the mrm and rmr PS stereoisomers show channel conformations with significant probabilities, so we suggest that in situ polymerization of styrene monomer in the narrow channels of its IC formed with γ-CD might produce a new stereoregular form of PS with regularly alternating m and r diads.     

基于部分信道信息的中继选择与功率分配算法

针对传统中继选择算法反馈开销大、信道条件利用不充分以及等功率分配算法资源利用率低等问题,在放大转发协作通信网络中,以最小化系统中断概率为目标,提出基于部分信道状态信息的中继选择与功率分配算法。指出源-中继-目的节点传输链路所能获得的信噪比受制于源-中继及中继-目的链路中接收信噪比较小者,各中继依据自身到源及目的节点链路的统计信道状态信息,采用不同的反馈策略向源节点进行信息反馈,由源节点完成中继选择,通过凸优化方法对所选择的源和中继节点进行功率分配。仿真结果表明,与基于第一跳信道信息的算法相比,该算法在仅增加少量反馈的条件下可明显降低系统的中断概率,且与同等反馈负荷下的其他算法相比,仍能获得较好的中断性能。     

聚四氟乙烯烧结成型的制备工艺

对聚四氟乙烯（PTFE）进行了压制试验和烧结试验，讨论了成型压力与试件的致密度、压缩强度以及压缩模量之间的关系，且对不同烧结工艺下试件的压缩强度进行了分析，得到较合适的成型压力和烧结工艺。结果表明：咖材料的压缩强度随压制压力的升高而减小，压缩模量随压制压力的升高而增加；闻的成型压力为27．5MPa，烧结温度380℃，保温时间4h。     

旋转变压器信号的标定与解调

针对检波后信号存在直流偏置、幅值不等和相位偏移等问题,采用梯度估计算法,对检波后的包络信号进行离线标定;并设计了基于状态观测器的旋转变压器-数字转换(RDC)算法,对标定后的包络信号进行解调.试验结果表明,梯度估计算法收敛速度快,估计精度高.与反正切法相比,所设计的RDC算法不需通过数值差分即可获得角速度信息,干扰抑制能力强,角位置和角速度估计精度高.     

浅层地震反射波法在过江通道勘察中的应用

浅层地震是工程地质勘察中的一种重要手段,其特有的高分辨率特性有利于确定地层界面、基岩起伏变化的形态。针对不同的地质情况,采用相应的野外观测方法,经过资料的解释、处理得到较好的效果。本文主要介绍浅层地震反射波法在某过江通道勘察中的地质效果。     

现代水声通信技术的发展及应用

本文介绍了通信技术中现代水声通信的历史,分析了水声通信发展的关键技术,讨论了水声信道的特点,并简要分析了水声通信技术的现状,对水声通信系统的特点作了一定的比较,最后对未来的水声通信技术作了预测。