枧田瓷石化学与矿物组成及其工艺性能研究

本文研究了枧田瓷石的化学与矿物组成及其工艺性能。利用XRF、XRD和FT—IR测试手段确定了瓷石的化学与矿物组成,结果表明：枧田瓷石由石英、高岭土、白云母和钠长石组成,其含量分别为56wt％、24wt％、13wt％和7wt％。采用DTA—TG和XRD分析瓷石的热分解过程,结果发现,白云母和高岭土发生了热分解,石英出现了晶型转变。1300℃煅烧后只存在石英和莫来石晶相,并且工艺实验表明其白度高达51,烧成收缩为4．9％,吸水率为0．14％,显气孔率为0.18％。     

V型滤池常用滤砂在给水处理中各参数的对比试验

文章通过对V型滤池常用的6种粒径滤砂进行过滤效果的对比试验研究,确定一种适合处理我国南方地区水质的均质滤料,使滤后水浊度达到小于0.1 NTU的处理效果。经过对不同滤砂的进出水浊度、水头损失以及过滤周期的一系列对比试验,6种滤料中粒径为1.0 mm的滤砂处理效果最好,达到所要求的处理效果。     

基于FCMISVM的自适应软测量建模算法及其在PX吸附分离过程中的应用

To overcome the problem that soft sensor models cannot be updated with the process changes, a soft sensor modeling algorithm based on hybrid fuzzy c-means (FCM) algorithm and incremental support vector machines (ISVM) is proposed. This hybrid algorithm FCMISVM includes three parts: samples clustering based on FCM algorithm, learning algorithm based on ISVM, and heuristic sample displacement method. In the training process, the training samples are first clustered by the FCM algorithm, and then by training each clustering with the SVM algorithm, a sub-model is built to each clustering. In the predicting process, when an incremental sample that represents new operation information is introduced in the model, the fuzzy membership function of the sample to each clustering is first computed by the FCM algorithm. Then, a corresponding SVM sub-model of the clustering with the largest fuzzy membership function is used to predict and perform incremental learning so the model can be updated on-line. An old sample chosen by heuristic sample displacement method is then discarded from the sub-model to control the size of the working set. The proposed method is applied to predict the p-xylene (PX) purity in the adsorption separation process. Simulation results indicate that the proposed method actually increases the model’s adaptive abilities to various operation conditions and improves its generalization capability.     

超声波探伤仪的线性误差测试方法分析

介绍了超声波探伤仪的工作原理,得出水平线性和垂直线性对缺陷定位和定量的影响.对超声检定装置(含脉冲信号发生器和标准衰减器)和参考试块这两种测量器具进行探讨,同时用两种测试方法分别进行试验,得出这两种测试结果的优劣,分析影响因素,并给出相应的使用建议.     

海洋平台管道自动焊接工艺研究

针对海洋平台运维工程管线厚壁管道对接接头的机器人自动焊接生产线要求,分别采用K-TIG、高频TIG焊及直流TIG焊等打底焊工艺,以及混氩保护气体条件下的脉冲MAG填充盖面焊工艺,对生产线的焊接工艺进行了工艺适应性研究,并按照美标ASME BPVC相关要求对焊接试验中的焊件进行了焊缝力学性能和X射线探伤,制定出一套可用于实际焊接生产焊接生产工艺参数,为管线管道的自动化焊接生产奠定了工艺基础。     

低碳MgO-C材料的抗热震性研究

以电熔大结晶镁砂、天然鳞片石墨、纳米炭黑、酚醛树脂、铝粉等为主要原料制备w(C)=3%的低碳MgO-C材料,以其抗热震性为考核指标,选取颗粒级配、复合抗氧化剂、石墨粒度和复合结合剂4个因素,进行了四因素三水平正交试验。结果表明:在本试验范围内,颗粒级配是影响低碳MgO-C材料抗热震性的主要因素,复合抗氧化剂次之,石墨粒度和复合结合剂的影响基本相当;通过极差分析确定,镁砂颗粒级配(3～1、1～0.088和≤0.088mm的镁砂的质量比)采用50:23:27,复合抗氧化剂采用Al2.5+Mg-Al0.5+B4C0.5,石墨粒度采用10μm的,复合结合剂采用炭黑N220+沥青+酚醛树脂,可制备出抗热震性最佳的低碳MgO-C材料。     

短周期螺柱焊在线分析系统

短周期电弧螺柱焊生产效率高,易于实现自动化,广泛应用于汽车工业。开发了由信号采集单元和分析软件构成的短周期螺柱焊在线分析系统。信号采集单元包含PIC18F4580单片机、电源、信号调理、外部存储器和RS485通信等电路,通过焊接状态判断、AD采样、数据存储和通信等程序,实现焊接电流和电压采集、存储和传输。分析软件采用Microsoft Visual Studio C#编写,操作界面由主窗口、焊接过程分析窗口、熔深阈值设置窗口和报警窗口等构成。DP600镀锌钢板焊接试验表明,开发的短周期螺柱焊分析系统能实时显示焊接电流和电压波形,提取焊接参数特征值,判断电弧的稳定性,熔深计算值与实测值相吻合,在线检测结论与外观目检、宏观检测和扭矩测试的结论一致。系统收集的原始数据可用于分析引起质量问题的具体原因。     

基于模糊算法的水下机器人路径规划研究

针对水下机器人的工作环境的复杂性与不确定性,为了提高自主式水下机器人与外部环境交互及自主航行的能力,结合视线导航原理与模糊控制算法,提出一种未知环境下水下机器人的局部路径规划策略,可实现机器人的实时避障功能。利用测距声呐、短基线系统对环境进行探测,得到一定范围内的障碍物与目标信息,通过模糊控制器实时调整水下机器人的运动偏转角度,有效地避开障碍物,达到预定目标点。最后通过MATLAB进行仿真,构建一个仿真实验平台,交互式设置障碍物的数量、大小、形状、位置等初始信息,机器人运用该算法在多障碍物、不同路障环境下,都能较好地实现机器人避障,验证了算法的有效性。     

Effects of surfactant and particle size on the microstructure and strength of Si3N4 foams with high porosity

The highly porous Si₃N₄ ceramic foams were prepared by direct foaming with mixed surfactants. The surface tension and viscosity of slurries were tailored by different carbon chain length of surfactants and different mean Si₃N₄ particle size to achieve the pore size controlling. The nearly linear relationship between the pore size and the ratio of surface tension to viscosity was observed, which indicates that the pore size could be precisely tailored by the slurry properties. Si₃N₄ ceramic foams with porosity of nearly 94%, mean pore size of 110–230 µm, and compressive strength of 1.24–3.51 MPa were obtained.