激光阈值附近微孔加工方法的研究

基于各个激光参数对加工微孔的影响以及激光在阈值附近工作时光束质量较好的优点,采用声光调QNd∶YAG脉冲激光器进行阈值附近的微孔加工,在0.7mm的镀锌钢板上获得了直径为15μm的微孔,深径比超过50,打孔成功率为100%。实验证实了此方法能实现高质量微细孔的激光制备。     

Formation of carbonaceous and nitrogenous disinfection by-products from the chlorination of Microcystis aeruginosa

Formation of carbonaceous disinfection by-products (C-DBPs), including trihalomethanes (THMs), haloacetic acids (HAAs), haloketones (HKs), chloral hydrate (CH), and nitrogenous disinfection by-products (N-DBPs), including haloacetonitriles (HANs) and trichloronitromethane (TCNM) from chlorination of Microcystis aeruginosa, a blue-green algae, under different conditions was investigated. Factors evaluated include contact time, chlorine dosages, pH, temperature, ammonia concentrations and algae growth stages. Increased reaction time, chlorine dosage and temperature improved the formation of the relatively stable C-DBPs (e.g., THM, HAA, and CH) and TCNM. Formation of dichloroacetonitrile (DCAN) followed an increasing and then decreasing pattern with prolonged reaction time and increased chlorine dosages. pH affected DBP formation differently, with THM increasing, HKs decreasing, and other DBPs having maximum concentrations at certain pH values. The addition of ammonia significantly reduced the formation of most DBPs, but TCNM formation was not affected and 1,1-dichloropropanone (1,1-DCP) formation was higher with the addition of ammonia. Most DBPs increased as the growth period of algal cells increased. Chlorination of algal cells of higher organic nitrogen content generated higher concentrations of N-DBPs (e.g., HANs and TCNM) and CH, comparable DCAA concentration but much lower concentrations of other C-DBPs (e.g., THM, TCAA and HKs) than did natural organic matter (NOM).     

基于FPGA的MEMS测量控制系统的设计

基于频闪显微干涉(stroboscopic interferometer vision system,SIVS)技术,提出了一种MEMS三维动态测量的同步控制系统.在该系统中,频闪的参数通过有USB功能的MCU从PC配置到FPGA中,然后由FPGA分别控制测量系统中的声光调制器、MEMS驱动器、微动平移台和千兆网相机.结合开发的应用软件,可以实时测量MEMS的运动.计算表明,使用该系统所能测量的MEMS的理论最高周期运动频率为1 MHz.实验证明这种方法行之有效.     

齿廓误差对齿轮时变系统拍击门槛转速的影响

建立了具有时变啮合刚度的二级齿轮系统的动力学方程式。用算符分解算法（AOM）研究了齿轮啮合误差和时变啮合刚度对拍击门槛转速的影响。结果表明,时变啮合刚度和齿面误差可以导致拍击;齿轮啮合频率、或者齿面误差频率等于派生系统的固有频率引起的共振是产生拍击的原因之一;低速端的齿面误差对系统拍击门槛转速影响较小,而高速端的齿面误差对拍击门槛转速影响较大;齿面误差对拍击门槛转速的影响不仅与自身的变化频率、幅值大小有关,更重要的是与时变频率及其组合频率有关。     

脱臭过程控制对油脂氧化稳定性的影响

本文介绍了什么是油脂氧化稳定实验,并对脱臭过程控制中油脂氧化稳定性进行了探讨。通过对脱臭蒸汽用量、进油流量、脱臭温度的单因素实验,并经过三个因素的正交实验,得出了脱臭过程控制中油脂氧化稳定性的最佳工艺条件。正交实验表明,在生产过程中油脂氧化稳定时间最长的工艺条件是:蒸汽用量70 KPa,进油流量24 m3/h,进油温度252℃,可使AOM值在3.17 h以上。     

LD抽运Nd:YVO4/KTP激光光强高频调制技术

用声光调制的方法将激光二极管(LD)抽运ND:YVO4/KTP激光进行光强调制,频率达15 MHz以上,衍射效率达40%～60%,满足了激光精密测量和新型激光彩色电视的技术要求,有很好的应用前景.     

基于Java EE 的AOM-Spring-Hibernate 架构及应用

针对传统开发方法在开发中小型Web 应用时的不足,研究了目前主流的基于Java EE 的轻量级框架技术,提出了一种基于AOM-Spring-Hibernate （ASH）整合框架的新的解决方案。该方案利用AOM 的视图控制反转（Inversion of View Control, IoVC）技术实现了表现层的页面设计与业务逻辑完全解耦,业务逻辑层采用Spring 技术,Hibernate 则将数据库中的表持久化为Java Bean。基于该方案,开发了一套适合于多批量少品种制造环境的精益生产管理系统,并在重 庆某企业得到成功应用。     

扭矩波动对齿轮时变系统拍击门槛转速的影响

建立了具有时变啮合刚度的二级齿轮系统的动力学方程式,它是一个具有时变系数的线性动力系统。用算符分解算法(AOM)研究了扭矩波动和时变啮合刚度对拍击门槛转速的影响。根据计算结果发现,时变啮合刚度可以导致拍击;齿轮啮合频率等于派生系统的固有频率引起的共振是产生拍击的原因之一;低速端的扭矩波动对系统拍击门槛转速影响较小,而高速端的扭矩波动对拍击门槛转速影响较大;在大部分情况下,考虑时变啮合刚度的二次谐波分量后,拍击门槛转速稍有下降。     

提高声光调Q光纤激光器输出功率的关键因素分析

声光调Q光纤激光器具有所需驱动调制电压很低，容易实现对连续激光调Q获得高重复频率脉冲输出的特点。介绍丁声光调Q光纤激光器的原理，并对影响它性能的几个重要因素如自发辐射的放大、泵浦功率和速率、光纤的选择、声光Q开关的重复频率等主要因素做理论分析，提出了优化这些因素的方法。     

Collaborative study of the oil stability index analysis

The Oil Stability Index Analysis method was subjected to a fifteen-laboratory collaborative study in which the participants used currently available commercial and home-built instruments to provide data to support the approval process as an Official Method of the American Oil Chemists’ Society. The overall average coefficient of variation was 11.3% for samples from 7 to 80 h of stability testing at 110°C.