Indirect model for roughness in rough honing processes based on artificial neural networks

In the present paper an indirect model based on neural networks is presented for modelling the rough honing process. It allows obtaining values to be set for different process variables (linear speed, tangential speed, pressure of abrasive stones, grain size of abrasive and density of abrasive) as a function of required average roughness Ra. A multilayer perceptron (feedforward) with a backpropagation (BP) training system was used for defining neural networks. Several configurations were tested with different number of layers, number of neurons and type of transfer function. Best configuration for the network was searched by means of two different methods, trial and error and Taguchi design of experiments (DOE). Once best configuration was found, a network was defined by means of trial and error method for roughness parameters related to Abbott–Firestone curve, Rk, Rpk and Rvk.     

Designing the NGC system of a small ASV for tracking underwater targets

The paper describes the development of the Navigation, Guidance and Control system of a small, prototypal Autonomous Surface Vehicle (ASV), which is part of an ASV/UUV (Unmanned Underwater Vehicle) robotic system. The main task of the ASV is to serve as supply vessel for the UUV it can carry, deploy and recover and to allow communication with a remote control station. The main problem the NGC system has to handle is that of making the ASV track the UUV and maintain the relative distance within a given bound, using delayed information about the UUV position provided by an acoustic tracking and positioning systems. The specific tracking problem is formulated in a suitable way and a strategy for its solution is proposed and implemented by means of an appropriate control architecture. Stability is discussed using Lyapunov techniques and performances are shown by means of simulations.     

某白酒企业废水处理系统改造工程

为执行《发酵酒精和白酒工业水污染物排放标准》(GB 27631—2011),四川某白酒企业对原污水处理系统进行了改造,主体工艺在原"UASB+接触氧化"的基础上增加了A2/O单元,并给UASB增加了回流。为提高化学除磷效果,在投加聚合氯化铝的基础上,加投了聚丙烯酰胺。改造后系统出水中COD、NH3-N、TN、TP、色度等指标均实现了稳定达标排放。     

Chemical Reactions Directed Peptide Self-Assembly

Fabrication of self-assembled nanostructures is one of the important aspects in nanoscience and nanotechnology. The study of self-assembled soft materials remains an area of interest due to their potential applications in biomedicine. The versatile properties of soft materials can be tuned using a bottom up approach of small molecules. Peptide based self-assembly has significant impact in biology because of its unique features such as biocompatibility, straight peptide chain and the presence of different side chain functionality. These unique features explore peptides in various self-assembly process. In this review, we briefly introduce chemical reaction-mediated peptide self-assembly. Herein, we have emphasised enzymes, native chemical ligation and photochemical reactions in the exploration of peptide self-assembly.     

The effects of electrical comminution on the mineral liberation and surface chemistry of a porphyry copper ore

The surface chemistry and mineral liberation changes of a porphyry copper ore after high voltage pulse (HVP) electrical comminution have been investigated using X-ray photoelectron spectroscopy (XPS) and mineral liberation analysis (MLA). Previous studies suggest that electrical comminution has the potential to improve downstream flotation recoveries, due to increased mineral liberation. However, until now the effects on the surface chemistry have not been investigated in detail.The mineral liberation results showed that chalcopyrite was more liberated in the electrical comminution product than in mechanical comminution, noticeably in the coarser size fractions. The surface chemistry of pure chalcopyrite was investigated, using XPS, and high resolution scans of iron and sulphur showed that both comminution methods led to iron oxidising preferentially leaving behind a passivating film of copper sulphides. However, the HVP product oxidisation was more severe with more iron oxide being produced and further oxidation of the remaining copper sulphides into copper sulphate. An attrition grinding stage may be useful in removing the oxidised layer from the surface of the particles prior to flotation separation. This paper presents a new application of the HVP technology in hybrid procedures using electrical comminution and mechanical grinding to prepare the flotation feed, rather than using excessive pulse energy to fully disintegrate ore to the flotation size. Better liberation and flotation performance were achieved through the hybrid procedures than the comparative mechanical comminution.     

《化学制药单元操控》工学结合课程的教学探索

《化学制药单元操控》是一门新开发的将情景教学、实验操作和仿真实训相结合的工学结合课程。其中,引入化工仿真教学这一新型的教学方式,即通过在非常逼真的操作环境中进行技能训练,使学生对实际生产装置有更加感性的了解和认识。本文对《化学制药单元操控》工学结合课程开发与实施应用过程进行分析和总结得到几点经验,同时分享对该门课程教学改革中的一些心得。     

Surface Treatment of ZrO2 Nanoparticles with Biosafe Citric Acid and Its Utilization for the Synthesis of L-leucine Based Poly(Amide–Imide) Nanocomposites

This study aimed at preparing three nanocomposites of optically active poly(amide–imide) and zirconium dioxide (ZrO₂) inorganic nanoparticles through the ultrasonic process. First, the surface of ZrO₂ nanocomposites was chemically modified with bio-active citric acid in the basic media. Then, the poly(amide–imide) was reinforced with modified nanocomposites and three poly(amide–imide)/ZrO₂-citric acid nanocomposites were synthesized by ultrasonic irradiation. The poly(amide–imide) was prepared by polycondensation of N-trimellitylimido-L-leucine with 4,4′-diaminodiphenylsulfone using of triphenyl phosphite and molten tetra-n-butylammonium bromide as green media. The obtained poly(amide–imide)/ZrO₂-citric acid nanocomposites were characterized by different techniques.     

基于网络控制的电机软启动器故障分析与控制系统改造

某公司低压电机应用某合资品牌软启动器配合网络完成启停及反馈控制方式,正常运行时频繁发生软启动器无故障报警停机。针对这一现象进行深入分析、总结,并对其进行国产化改造,以保证设备运行可靠性及生产的稳定性。