光电窥膛自控系统

提出一种用于炮膛疵病损伤检测的光电窥膛自控系统。该系统由上位机和下位机子系统组成。上位机子系统为计算机主控单元 ,下位机子系统以单片机为核心。上、下位机子系统通过串行口进行通信 ,由上位机产生驱动摄像单元步进电机的控制信号 ,经过单片机处理 ,实现对步进电机的控制 ,从而使光电窥膛头完成前进、前进预置、后退、旋转、侧视特写、前视搜索等多种功能 ,并实现对膛内疵病的高精度测量和定位     

端口概念及应用的仿真演示实验

端口概念是微机原理及嵌入式系统相关课程中的关键概念之一。通过简单的设计实例,结合硬件原理和输入输出指令的执行时序,分析了端口的作用,端口地址的本质及形成过程。给出了Proteus环境下实验系统的仿真调试结果。     

港口选择研究进展

从港口选择问题演化、港口选择决策人、港口选择决定因素、枢纽港选择以及研究方法等方面系统地阐述了国内外港口选择的研究动态和主要论点，并探讨了未来港口选择研究的方向和特点。     

基于XMC4500的汽车CAN网络检测卡设计

CAN总线作为车用网络的主要应用总线技术,通过CAN总线获得汽车运行时的实时数据成为汽车电子系统研发、维修及故障分析的主要手段;在对传统CAN总线检测卡分析及研究的基础上,为了使移动PC更加便捷地分析及记录汽车CAN网络中的数据,使基于串口通讯的系统及应用软件能够方便地继承使用,设计了基于XMC4500单片机的汽车CAN网络检测卡;实现了将汽车CAN网络中的数据通过USB端口虚拟的高速串口传输至上位机、实时备份相关数据到Micro SD卡中的功能;实验数据显示在最高1 000 kb/s的传输速率下,能够100%正确接收及存储相关数据,满足对该卡实时性和可靠性的要求。     

Simplified Derivatization Method for Triclosan Determination in Personal Care Products by Gas Chromatography‐Mass Spectrometry

An efficient and eco‐friendly injection‐port tert‐butyldimethylsilylated (TBDMS) derivatization and gas chromatography‐mass spectrometry (GC‐MS) was developed to determine triclosan (TCS, an antibacterial agent) in the samples of toothpaste, liquid hand‐soap and facial cleansing cream. This on‐line derivatization coupled ultrasonic extraction provides sensitivity, fast and reproducible results for TCS analysis. The accuracy and precision of the method was evaluated. The developed method was successfully applied to determine the content of TCS in selected personal care products.     

Ultrasound‐assisted emulsification microextraction combined with injection‐port derivatization for the determination of some chlorophenoxyacetic acids in water samples

An efficient method based on ultrasound‐assisted emulsification microextraction followed by injection‐port derivatization GC analysis was developed to determine 2,4‐dichlorophenoxyacetic acid (2,4‐D) and 4‐chloro‐2‐methylphenoxyacetic acid (MCPA) in natural water samples. In this procedure, 12.5 μL of 1‐undecanol was injected slowly into a 12 mL home‐designed centrifuge glass vial containing an aqueous sample of the analytes located inside an ultrasonic water bath. The resulting emulsion was centrifuged, and 1 μL of the separated organic solvent together with 1 μL of the derivatization reagent were injected into a GC equipped with a flame ionization detector. Several factors that influence the derivatization and extraction were optimized. Under the optimal conditions, the LODs were 0.33 and 1.7 μg/L for MCPA and 2,4‐D, respectively. Preconcentration factors of 670 and 836 were obtained for MCPA and 2,4‐D, respectively. The precision of the proposed method was evaluated in terms of repeatability, which was <5.7% (n = 5). The applicability of the proposed method was evaluated by extraction and determination of chlorophenoxyacetic acids from some natural waters, which indicated that the matrices of natural waters have no significant effect on the extraction and derivatization efficiency of this method.     

切向管结构对涡流二极管性能影响的数值模拟

为研究涡流二极管切向管结构对其性能及内部流场的影响,本文采用SIMPLE算法、κ-ε模型对锥角为0.(直筒型),3°、5°、7°和10°的五种切向管结构模型进行了数值模拟.结果表明:随着切向管锥角的增大,由于强制涡速度的提高,反向阻力系数随之增大,同时由于切向管中涡量的增大,正向阻力系数也随之增大.直筒型切向管结构ε值...     

宁波港船舶进出主航道分道通航方案探讨

随着宁波港吞吐量的迅速增长，虾峙门航道单向通航已不能适应港口的发展需要．针对宁波港的发展规划提出三套可行性分道通航方案，在进行航道规划时作参考，以保持宁波港可持续稳定的发展．     

红外多干扰目标模拟器电控系统的实现

红外多干扰目标模拟器提供了一个虚拟的仿真环境,通过模拟红外目标及其释放的干扰的运动情况对红外制导导弹的性能进行测试.在其电控系统的设计中,采用双口RAM来进行多机通讯,并采用了多种控制方法,使系统各性能需求得以较好地实现。     

组合评价模型在港口物流综合服务能力评价中的应用

为了对港口物流综合服务能力进行科学评价,提出了基于组合评价方法的港口物流服务能力评价模型,并对我国15个港口的物流综合服务能力进行实证分析说明模型的有效性.首先分别采用5种评价方法进行评价,然后使用KendallW系数检验各方法评价结果的一致性,再运用4种组合评价模型进行组合评价,采用Spearman等级系数进行事后检验并得到最终结果.方法可克服单一评价方法的不足,为港口物流服务能力评价提供新的思路.