基于LM628的光谱分析仪波长定位系统

本文介绍了基于LH628的光谱分析仪波长定位系统,详细阐述了其原理及具体实现。     

Langmuir–Blodgett films of stearic acid deposited on substrates at different orientations relative to compression direction: alignment layer for nematic liquid crystal

The Langmuir monolayer at an air–water interface shows remarkably different surface pressure (π)–area (A) isotherm, when measured with the surface normal of a Wilhelmy plate parallel or perpendicular to the direction of compression of the monolayer. Such difference arises due to difference in stress exerted by the monolayer on the plate in different direction. In this article, we report the effect of changing the direction of substrate normal with respect to the compression of the monolayer during Langmuir–Blodgett (LB) film deposition on the morphology of the films. The morphology of the LB film of stearic acid is studied using an atomic force microscope. The morphology of the LB films is found to be different due to difference in the stress in different directions. The role of such surface morphology on the alignment of a nematic liquid crystal (LC) in LC cells is studied. The granular texture of LB films of stearic acid supports the homogeneous alignment of the LC whereas the uniform texture supports the homeotropic alignment of the LC.     

治疗非小细胞肺癌脑转新药:Zorifertinib

新药Zorifertinib是阿斯利康公司针对非小细胞肺癌(NSCLC)脑转研发的一种表皮生长因子酪氨酸激酶抑制剂(EGFR-TKI),对EGFR 19外显子缺失和EGFR 21外显子L858R突变有高选择性和高抑制性,相较于其他EGFR-TKIs的突出优势是具有优秀的血脑屏障渗透性。临床研究表明Zorifertinib可以在脑内达到等同血浆的药物浓度,有效抑制脑内肿瘤生长,减少脑内肿瘤面积,并且预防脑内肿瘤形成。本文将对该新药的作用机制、研发历程、药代动力学、临床研究和安全性进行综述,为广大研究者以及今后的临床应用提供参考。     

A transformed random effects model with applications

This paper proposes a transformed random effects model for analyzing non-normal panel data where both the response and (some of) the covariates are subject to transformations for inducing flexible functional form, normality, homoscedasticity, and simple model structure. We develop a maximum likelihood procedure for model estimation and inference, along with a computational device which makes the estimation procedure feasible in cases of large panels. We provide model specification tests that take into account the fact that parameter values for error components cannot be negative. We illustrate the model and methods with two applications: state production and wage distribution. The empirical results strongly favor the new model to the standard ones where either linear or log-linear functional form is employed. Monte Carlo simulation shows that maximum likelihood inference is quite robust against mild departure from normality. Copyright © 2009 John Wiley & Sons, Ltd.     

基于ARM的智能化公寓安防测控系统设计

针对宿舍安全需求,遵循可靠性、独立性、安全性、联动性、扩展性、实用性、经济性的原则设计出了一个基于ARM的智能化公寓防盗防火报警系统。该系统采用Easyarm LM3S1138、RS232总线和多种传感器,实现了异地控制和多终端网络同步控制。经测试表明,该系统不仅实现了人体检测、烟雾检测、声光报警、键盘密码解警以及宿舍内贵重物品进出情况记录等功能,且具有电路设计简单、可靠性高、人机交互友好和成本低的特点。     

基于改进BP网络的柴油机燃油故障诊断的应用

针对标准BP神经网络收敛速度较慢的问题,本文对所建立的BP网络的学习算法进行了改进,采用LM最优化算法对BP网络进行训练,替代了原来标准BP算法中的梯度下降法寻找最优网络连接权值。燃油喷射系统是柴油机的核心部分,其工作状况直接影响柴油机的燃油过程及其性能,将这种改进的BP算法应用到柴油机燃油故障诊断中,仿真实验证明,该...     

基于国半LM3886的高保真合并式音频功率放大器

顺应当前节能减排的原则,开发了一款性价比极高、性能较完善的基干国半LM3886的高保真合并式音频功率放大器,该合并武音频功率放大器能匹配绝大多数书架音箱.实测指标与实际试听都达到较高水平.     

汽车倒车雷达系统的设计与实现

为避免汽车倒车过程中发生碰撞,设计一种基于单片机AT89C51的倒车雷达系统,介绍了超声波测距的基本原理,阐述了倒车雷达系统的结构组成、硬件电路设计以及软件设计,并在数据处理部分采用温度补偿消除温度时声速的影响,提高了测距精度.倒车距离采用LCD进行实时显示,并通过语音报警电路对不同距离段做出不同的语音提示.实验表明该倒车雷达系统在30～500 cm范围内可实现准确测距,具有可靠性较高、外围电路简单、实用性强等优点.     

基于STC89C58数字温度计的设计与实现

介绍一种数字温度计的设计制作方案.通过采用LM94022作为温度传感器芯片,FM1602C液晶显示作为温度显示,TLC2543CN作为ADC采样转换器,STC89C58作为数字温度计控制核心相结合,设计制作了宽量程高精度多功能数字温度计.概述了数字温度计设计思路及总体方案,另外对各单元电路也做了详细分析.该数字温度计不仅分辨率高,还可以设置报警温度上下限,当温度达到高、低限温控制点时发出声光报警.     

关于电视响度测量问题的解决

现在观众有越来越多的节目可供选择，但是不同节目间却存在着响度差异过大的问题。杜比实验于2003开发出了LM100广播响度测试仪，能够外部节目、本地节目以及广告之间的对白响度一致性，本文LM100的技术特点和实际应用进行了介绍。