基于SPCE061A单片机的髋作用力测试仪设计

介绍了基于SPCE061A单片机的髋作用力测试仪的系统结构及部分软件编写流程,着重分析了测试仪的测力方法以及使用光电编码器进行测速和鉴相的原理.测试仪以SPCE061A单片机为控制核心,配有串行通信口,具备上位机实时监控、数据保存和复现、测试数据离线分析等功能.实验证明,该测试仪具有测量准确、稳定性高及操控界面友好等优点.     

Coverage by randomly deployed wireless sensor networks

One of the main applications of wireless sensor networks is to provide proper coverage of their deployment regions. A wireless sensor network k-covers its deployment region if every point in its deployment region is within the coverage ranges of at least k sensors. In this paper, we assume that the sensors are deployed as either a Poisson point process or a uniform point process in a square or disk region, and study how the probability of the k-coverage changes with the sensing radius or the number of sensors. Our results take the complicated boundary effect into account, rather than avoiding it by assuming the toroidal metric as done in the literature.     

Broadband high-efficiency circularly polarized active antenna and array for RF front-end application

This paper presents a broadband high-efficiency circularly polarized (CP) active integrated antenna, and a broadband CP active array at 2 GHz. To realize the broadband CP antenna, a circular patch is aperture coupled by crossed slots in the ground plane, which are fed by an L-shaped microstrip feed line below the ground. The antenna is designed to serve the functions of both a radiator and a harmonics-terminated load for class-E high-efficiency power-amplifier (PA) integration. The broadband CP active antenna is realized by directly integrating the broadband CP antenna with the class-E PA. It achieves a 9% bandwidth (1.84-2.01 GHz) for axial ratio (AR) below 3 dB, and a 12% bandwidth for power-added efficiency (PAE) over 60%. To form the broadband CP active array, four active antenna elements are sequentially rotated, and each element is directly integrated with broadband class-E PA. A low-cost printed-circuit-board technology is employed in fabrication and a pseudomorphic high electron-mobility transistor is used. A peak drain efficiency of 71.5% for the class-E amplifier is measured at 1.95 GHz. The active array achieves a peak-effective radiated power of 39.7 dBm, and PAE is over 50% within a 22.6% bandwidth (1.72-2.16 GHz). The AR is below 3 dB over a 27% bandwidth (1.72-2.26 GHz).     

Symbol error rate of selection amplify-and-forward relay systems

Cooperative diversity schemes significantly improve the performance of wireless networks by transmitting the same information through several nodes. The amplify-and-forward (AF) relaying method is one of the most attractive cooperative diversity schemes due to its low complexity. Selection AF relaying has recently been proven to achieve the same diversity order as and lower outage probability than all-participate relays. In this letter, we present an asymptotic analysis of the symbol error rates of a selection AF network, and compare it with the conventional all-participate scheme     

纳入城市规划、规范移动通信基站建设

本文分析了目前移动基站建设存在的主要问题及其产生根源,提出规范移动通信基站建设,将其作为城市公用设施纳入城市规划的观点.并根据国家及政府有关部门的政策法规及国内先行城市的成功经验,结合本市的实际情况,对规范移动通信基站建设的本地立法工作提出了建议.     

梅纽因:世纪小提琴

EMI公司于2005年新出 版的这款《梅纽因:世 纪小提琴》,用传记性方 式和珍贵的影音资料, 概述了20世纪最杰出的小提琴家耶胡 迪·梅纽因的艺术生涯。 这张影碟由“序言”、“出生”、“神 童”、“非凡事业”、“赫夫齐巴”、“相遇”、 “流浪小提琴”、“触摸声音的耳朵”、“尾     

Parameter Extraction for 2-π Equivalent Circuit Modelof RF CMOS Spiral Inductors

从有理分式拟合方法出发，提出了用于射频CMOS平面螺旋电感2-π等效电路模型参数提取的新方法. 通过比较提参后等效电路给出的S参数和实验测量的S参数，证明该方法的精度很高. 此外，提参的策略非常直接，因此容易在CAD里面编程实现. 提参得到的等效电路模型对于射频电路设计者来说也是非常有用的.     

基于亲水表面处理的GaAs/GaN晶片直接键合

对晶片进行亲水表面处理,在氮气保护下500℃热处理10min,成功实现GaAs与GaN晶片的直接键合,键合质量较好.扫描电子显微镜观测结果表明,键合界面没有空洞.光致发光谱观测结果表明,键合工艺对晶体内部结构的影响很小.可见光透射谱测试结果表明,键合界面具有良好的透光特性.GaAs与GaN晶片直接键合的成功,为实现GaAs和GaN材料的集成提供了实验依据.     

Visible Light-Driven Alkyne-Grafted Ethylene-Bridged Azobenzene Chromophores for Photothermal Utilization

Molecular photoswitches are considered to be important candidates in the field of solar energy storage due to their sensitive and reversible bidirectional optical response. Nevertheless, it is still a daunting challenge to design a molecular photoswitch to improve the low solar spectrum utilization and quantum yields while achieving charging and discharging of heat without solvent assistance. Herein, a series of visible-light-driven ethylene-bridged azobenzene (b-Azo) chromophores with different alkyne substituents which can undergo isomerization reactions promoted in both directions by visible light are reported. Their visible light responsiveness improves their solar spectrum utilization while also having high quantum yields. In addition, as the compounds are liquids, there is no need to dissolve the compounds in order to exploit this switching. The photoisomerization of b-Azo can be adjusted by alkyne-related substituents, and hexyne-substituted b-Azo is able to store and release photothermal energy with a high density of 106.1 J·g⁻¹, and can achieve a temperature increase of 1.8 °C at a low temperature of −1 °C.     

Surface Functionalized Magnetic Nanoparticles as a Selective Sorbent for Affinity Fishing of PPAR-γ Ligands from Choerospondias axillaris

Coronary heart disease (CHD), which has developed into one of the major diseases, was reported to be treated by the target of peroxisome proliferators-activate receptor γ (PPAR-γ). As a natural medicine long used in the treatment of CHD, there are few studies on how to screen the target active compounds with high specific activity from Choerospondias axillaris. To advance the pace of research on target-specific active compounds in natural medicines, we have combined magnetic ligand fishing and functionalized nano-microspheres to investigate the active ingredients of PPAR-γ targets in Choerospondias axillaris. The PPAR-γ functionalized magnetic nano-microspheres have been successfully synthesized and characterized by vibrating sample magnetometer (VSM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The specificity, reusability, and reproducibility of the nano-microspheres were investigated with the help of the specific binding of rosiglitazone to PPAR-γ. In addition, the incubation temperature and the pH of the buffer solution in the magnetic ligand fishing were optimized to improve the specific adsorption efficiency of the analytes. Finally, with the aid of ultraperformance liquid chromatography plus Q-Exactive Orbitrap tandem mass spectrometry (UHPLC-Q-Exactive Orbitrap-MS/MS), the 16 active ligands including 9 organic acids, 5 flavonoids, and 2 phenols were found in the ethanolic extracts of Choerospondias axillaris. Therefore, the study can provide a successful precedent for realizing the designated extraction and rapid isolation of target-specific active ingredient groups in the complex mixtures.