温岭市东部新区北片污水处理厂工程设计方案

在温岭市东部产业集聚区的北片建成了温岭市东部新区污水处理工程—北片污水处理厂,近期处理规模为1万m3/d。采用多点进水A/A/O工艺,集约化布置,曝气采用抽吸式曝气搅拌一体机,深度处理采用微絮凝＋无阀滤池,尾水经加氯消毒后达到GB 18918—2002一级A排放标准后外排,部分回用于新区。该文介绍了该厂的处理工艺和设计参数,并对工程设计中需要考虑的问题进行了分析,总结了工程特点。     

Manufacturing polymer/clay nanocomposites through elongational flow technique

A novel processing technique that employs continuous elongational flow to fabricate polymer/clay nanocomposites has been developed and evaluated in this work. A self-made vane mixer has been used to supply the continuous elongational flow, while high-density polyethylene (HDPE) and organic montmorillonite (O-MMT) were used as the polymer matrix and clay, respectively. The morphology of resultant nanocomposites has been carefully revealed and studied by examining wide-angle X-ray diffraction (WAXD) and transmission electron microscopy (TEM). Intercalation effect and dispersion of O-MMT layers have been investigated by the morphology study. The results indicate that the elongational flow has a great potential in melt intercalation of O-MMT, and can lead to an orderly O-MMT layers’ distribution. Thermal properties of as-mixed nanocomposites that prepared under elongational flow have been determined by the differential scanning calorimetry (DSC), which demonstrates that the introduction of O-MMT nano-sheets is bad for the crystal of HDPE matrix. The universal tensile test shows how O-MMT layers affect the mechanical properties of nanocomposites, including the tensile strength and elongation at break. The strain–stress relationship reveals that with continually adding O-MMT layers, the tensile strength increases at first, and then decreases. While the elongation at break shows the same trend.     

Flux Improvement during Cross-flow Microfiltration of Wheat Starch Suspension using Turbulence Promoter

The objective of this study was to investigate the effects of the process variables (transmembrane pressure, flow rate, and concentration) on the permeate flux during the microfiltration of model starch suspensions, and to determine the conditions under which the use of Kenics statics mixer as a turbulence promoter is justified. A response surface methodology was used to examine the influence of the selected operating conditions on starch suspension microfiltration using a single channel ceramic membrane with 200 nm pore size. The experimental results clearly show that the improved performance of starch suspension cross-flow microfiltration can be obtained by using a Kenics static mixer, especially at lower flow rates. Compared to the operation without the turbulence promoter, the average permeate flux improvement during the filtration period ranged from 30% to 230%. As a result of the statistical analysis, the optimal conditions for starch suspension microfiltration were determined and applied to microfiltration of starch industry wastewater.     

A statistical analysis on the mechanical properties of nanocomposite modified asphalt mixtures

This study aimed to characterize the rate of change that takes place in the mechanical properties of polymer-nanocomposite asphalt (PNMA) mixtures due to altering asphalt binder grade and styrene-butadiene-styrene (SBS) type. Laboratory testing program included Marshall stability, resilient modulus, and wheel-tracking tests. Test results were compared and analyzed statistically by means of two-way analysis of variance and Tukey test. Variance analysis indicated the significant effect of both binder type and SBS grade on mechanical properties of asphalt mixtures. Interaction between binder type and SBS grade is also meaningful in all the experiments. The results also show that the binder type is the primary affecting factor, followed by the SBS grade.     

潜水搅拌器叶轮设计及搅拌流动研究

基于环流理论实现潜水搅拌器叶轮设计,应用Fluent软件对其产生的复杂搅拌流场进行数值求解。结果表明:搅拌器叶轮运行时产生旋向射流,利用体积流来输送液体。通过改变搅拌器叶轮的设计参数,对模拟结果进行对比分析,提出优化设计方案,现场运行效果良好,效益显著。     

矿用充填料搅拌机研究进展

介绍了矿山所使用充填搅拌机的特性和开发新型充填搅拌机的必要性,总结了近期国内外对矿用充填搅拌机研究开发的现状,并对新型矿用充填搅拌设备研制发展趋势作了展望。     

OGFC沥青混合料组成设计与施工工艺研究

采用SinoTPS对基质沥青进行了改性,并拌制沥青混合料,进行了OGFC的配合比设计,确定了矿料配合比例以及最佳油石比;通过OGFC沥青路面试验段的铺筑,提出了OGFC沥青混合料拌合、运输、摊铺和碾压中的质量保证措施。     

塔河油田重质原油脱硫工艺优化与应用

塔河油田属于奥陶系油气藏,所产原油物性主要表现为粘度高、密度大、富含硫化氢,进入油田生产系统后,对设备装置、原油储罐、管线等关键要害部位腐蚀较大,往往造成系统不稳定,同时在生产环节中,塔河原油容易逸散出高浓度的硫化氢,对环境和人造成极大的影响和危害。如何结合现有实际情况,降低原油硫化氢含量是需要解决的问题。针对问题,提出了在上游原油集输站库加装静态混合器进行脱硫工艺优化的解决措施,使原油硫化氢含量、脱硫剂单位成本费用两项关键控制指标大幅降低,取得了较好的经济效益和社会效益,具有较强的推广价值和应用前景。     

20GHz镜频抑制谐波混频器

镜频抑制混频器能有效地抑制镜像频率,提高雷达和通信系统的抗干扰能力。介绍了一个20 GHz二次谐波镜频抑制混频器的设计与制作,该镜频抑制混频器采用两个相同的二次谐波混频器做为两路混频单元,两路射频输入和中频输出分别用90°的功分器/合路器与两路混频器相连,本征用威尔金森功分器等幅同相输入两路混频。借助于90°的功分器,两路混频器的镜频产物在中频90°合路器的输出端口反相抵消,有用中频在90°合路器的输出端口同相叠加。利用ADS和HFSS对该混频器进行了仿真设计,并对实际电路进行了加工测试。经测试,当中频固定在400 MHz时,射频在20～21 GHz内变频损耗小于10 dB,镜频抑制大于20 dB。     

基于薄膜工艺的x波段下变频器设计

本文介绍了一个基于薄膜电路工艺设计、加工的X波段下变频器.首先对整体方案进行分析论证,然后运用安捷伦公司的ADS仿真设计软件,对射频及中频滤波器、朗格电桥、低噪声放大器和混频器等电路单元及变频器系统进行了仿真设计.最后经过加工测试验证,该变频器性能指标良好.其工作频率为9.35GHz - 9.85GHz,变频增益≥26dB,噪声系数≤2dB,P01dB压缩点功率≥10dBm,输入、输出驻波≤1.3,镜像抑制比≥50dB;本振输入为0±1dBm.整个电路腔体结构尺寸为70mm×20mm×10mm.