弹道导弹的雷达探测系统仿真

该文根据弹道理论建立了雷则弹道导弹的仿真模型,并对雷达跟踪的导弹弹道数据进行了处理,预报了它的落点范围,并与理论落点进行比较,给出了落点精度。仿真结果表明：雷达对导弹的探测数据经过一数据处理,所得到的落点比较精确。     

Surface treatment,reflectance, and age effects on electronic‐paper reading performance

Abstract— This study is intended to explore the legibility and visual fatigue of different age users under various surface treatments and reflectance of electronic paper. Through the method of character‐search task, the results indicated that compared with single types of treatment [anti‐reflection (AR) 0.8%, anti‐glare, 43% haze), the compound treatment of anti‐reflection and anti‐glare (ARC) exhibited the same legibility, and it showed superior properties to effectively reduce visual fatigue. Hence, it is suggested that electronic‐paper manufacturers should choose the compound surface treatment for better visual performance. On the other hand, the findings also validated that enhancing the reflectance of electronic paper to the same level as regular paper (about 80%) is worthy to be practically implemented. Based on the results of this study, electronic‐paper manufacturers can take useful information to fulfill ergonomic requirements on product design.     

Impacts in multibody systems: modeling and experiments

This paper outlines a novel approach to the modeling and analysis of impact involving multibody systems. This approach is based on an analysis of energy absorption and restitution during impact, using a decomposition of the kinetic energy, which decouples the parts associated with the spaces of admissible and constrained motions of the underlying unilateral constraints. Such a decomposition turns out to be useful in the analysis of energy dissipation during impact, and leads to a generalized definition of the energetic coefficient of restitution, which targets particularly collisions in multibody systems. The applicability of the approach reported is investigated by conducting an experimental study on a robotic testbed. It is shown that impact between multibody systems is considerably affected not only by the local dynamics characteristics of the interacting bodies, but also the configuration of the whole multibody system. The results reported here show that our decomposition can offer a sound characterization of impact in several problems of multibody systems.     

基于ARM+uC/OS-Ⅱ的超声波水煤浆粒度检测仪的设计

根据超声波在水煤浆中传播的声学特性的变化与水煤浆粒度之间的函数关系,基于低功耗32位嵌入式微处理器LPC2210与实时操作系统uC/OS-Ⅱ,文章提出了一种智能型水煤浆粒度快速检测仪的设计方案,并在测时电路里运用了锁相环技术,提高了超声传播时间的测量精确度。实际运行证明,该检测仪能满足实际测定水煤浆粒度的要求。     

Empirical Evaluation of User Models and User-Adapted Systems

Empirical evaluations are needed to determine which users are helped or hindered by user-adapted interaction in user modeling systems. A review of past UMUAI articles reveals insufficient empirical evaluations, but an encouraging upward trend. Rules of thumb for experimental design, useful tests for covariates, and common threats to experimental validity are presented. Reporting standards including effect size and power are proposed.     

宽带高效超声波传感器的研究

提出了一种新型的双层压电结构超声波传感器 ,借助于移相电容器的移相作用 ,改变各压电层的激励电压的幅值和相位 ,实现对传感器频率特性的控制 ,从而得到了具有宽频带高效率的超声波传感器 ,为研究宽带高效超声波传感器探索了一条新的途径     

光三角式传感器测距系统

主要介绍了光三角式距离传感器测距系统的结构组成和原理 ,分析了参数之间的转换关系 ,论述了以单片机为核心构成检测电路的原理和性能 ,以及单片机的软件功能。最后给出检测系统的主要技术指标。     

Design of an auditory guidance system for the blind with signal transformation from stereo ultrasonic to binaural audio

We have designed an auditory guidance system for the blind using ultrasonic-to-audio signal transformation. We first investigated the system requirements, and designed a simple but useful portable guidance system for the blind. The system derives visual information using multiple ultrasonic sensors, and transforms it to binaural auditory information using a suitable technique. The user can recognize the position of obstacles and the surrounding environment. The system is composed of two parts. One is a glasses-type system, and the other is a cane-type system with guide wheels. The former functions as an environment sensor, and the latter functions as a clear-path indicator. Wide-beam-angle ultrasonic sensors are used to detect bojects over a broader range. The system is designed as a battery-supplied portable model. Our design is focused on low power consumption, small size, light weight, and easy manipulation.     

Surface Modification of Reinforcement Fibers for Composites by Acid Treatments

In this study, we investigated the surface modification of reinforcement fibers for composites by acid treatments, including PBO fiber, Kevlar fiber and carbon fiber. The corresponding changes in the surface free energy components were carefully evaluated using a Cahn dynamic contact angle analysis system. In addition, the fiber's surface elemental composition and topography were studied using X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The results showed that the surface nitrogen-to-carbon (N/C) and oxygen-to-carbon (O/C) ratios were significantly increased after the treatments. The surface free energy of PBO fiber was increased from 43.3 mJ/m² to 58.5 mJ/m² or by 35% with 60 wt% methanesulfonic acid solution treatment for 36 h. However, the increase with 60 wt% nitric acid solution was only by 14% (to 49.5 mJ/m²) for the same treatment time.     

改性淀粉絮凝剂的开发与应用

淀粉来源广，价格低廉，产物可完全生物降解，因此淀粉改性絮凝剂的研究发展迅速。淀粉改性絮凝剂包括非离子型、阴离子型和阳离子型，文中综述了近十年来我国在这几方面的研究开发与应用方面的进展，并对今后进一步的研究提出了一些建议，建议今后加强实际工艺的研究，充分考虑到影响絮凝剂对废水处理效果的因素，开发出更加有效的絮凝剂。