Nitrogen removal using recycled polystyrene bottles as biofilm media

The performance of an attached growth wastewater treatment process was investigated in an effort to improve nitrogen removal efficiency. Recycled Yakult (lactic acid fermentation drink) bottles made of polystyrene were used as a biofilm media. The use of Yakult bottles as a biofilm media has been attempted by numerous researchers in Japan for the removal of solids and organics. However, these studies focused only on the removal of solids and organics. This study extended their application to the removal of nitrogen for domestic sewage treatment. Yakult media was placed in a reactor with 70% apparent reactor volume in a conventional A/O process. The bottom of the Yakult media was removed, and randomly filled Yakult media were effectively able to reduce the flow in tanks, resulting in an increase in the contact time between pollutants and microorganisms. With higher HRT, the nitrogen removal efficiency was increased by up to 83% with 12 hr of HRT. Nitrification appeared to be the limiting factor of nitrogen removal at an HRT that is less than 12 hr, indicating that the Yakult process requires more retention time to achieve nitrification compared to other biofilm processes. The removal efficiencies of organics and solids were high regardless of the change of operational parameters. This article is based on a presentation in “The 7th Korea-China Workshop On Advanced Materials” organized by the Korea-China Advanced Materials Cooperation Center and the China-Korea Advanced Materials Cooperation Center, held at Ramada Plaza Jeju Hotel, Jeju Island, Korea on August 24–27, 2003.     

Ce在铁基溶液中分别与Cu,P,Ti相互作用规律的研究SCIEI

Fe-Cu-Ce,Fe-P-Ce和Fe-Ti-Ce溶液的平衡产物是Ce_2O_2S,而不是Ce与Cu、P、Ti的金属间化合物。测定了Fe液中Ce_2O_2S=2[Ce]+[O]+2[S]反应的平衡常数和溶质之间的相互作用系数。Ce降低Cu和Ti在Fe液中的活度,增大其溶解度,同时增大P的活度,降低其溶解度。     

几种金属副在NaCl溶液中的抗蚀耐磨性能评价

应用电化学测试手段，针对20、2Cr13、QAl 9-2、QA l 10-3-15和QAl 10-4-4五种材料试件，分别测定了它们在NaCl溶液中的腐蚀电位及与QAl 9-2偶接时的电偶腐蚀电流的变化.并对几种铝青铜材料和QAl 9-2构成的摩擦副进行了摩擦磨损性能分析.结果表明，铝青铜材料的抗腐蚀性比钢好.其中QAl 10-4-4的腐蚀电位最为偏正，但它与QAl 9-2配副会对QAl 9-2产生较大的阳极电偶腐蚀；QAl 9-2与QAl 9-2相配时的电偶腐蚀最小，但其摩擦相溶性最差；而QAl 9-2与QAl 10-3-15材料副的抗电偶腐蚀能力和摩擦相溶性均佳.     

Characteristics of ZnO thin film deposited on various metal bottom electrodes

ZnO films for electronic applications were deposited by radio-frequency (rf) sputtering onto various metal bottom electrodes (Pt/Ti, W, Ni) to investigate such structural properties as crystallinity and surface morphology. The crystallinity, surface morphology and composition of the as-deposited films were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM) and Rutherford back-scattering spectrometry (RBS), respectively. The preferred orientation and surface morphologies were strongly influenced by the type of bottom electrodes. The ZnO films with (200) texturing deposited on Pt/Ti/SiO₂/Si showed a smoother and smaller grain size than those deposited on W and Ni. The ZnO films on Pt and W electrodes exhibited compressive residual stress. This article is based on a presentation made in the 2002 Korea-US symposium on the “Phase Transformations of Nano-Materials”, organized as a special program of the 2002 Annual Meeting of the Korean Institute of Metals and Materials, held at Yonsei University, Seoul, Korea on October 25–26, 2002.     

PbS和PbO反应动力学及其机理SCIEI

本文得出了PbS和PbO交互反应的速率方程:(da)/(dt)=kx_(PbS)~3x_(PbO)^(-2);发现了反应过程中有过渡产物碱式硫酸铅(PbSO_4·2PbO);从电子转移角度,探讨了反应机理。     

Low-energy ion beam treatment of α-Al<Subscript>2</Subscript>O<Subscript>3</Subscript>(0001) and improvement of photoluminescence of ZnO thin films

A low energy N₂ ^? ion beam impinged on a α-Al₂O₃(0001) single crystal surface in the range of fluence 5×10¹⁵/cm²?1×10¹⁸/cm² at room temperature. After ion bombardment, chemical bonding on the modified sapphire surface was investigated by x-ray photoelectron spectroscopy. Below a fluence of 1×10¹⁵/cm², only a non-bonded N1s peak at the binding energy 398.7 eV was found, but further irradiation up to 2×10¹⁷/cm² induced Al?O?N bonding at around 403 eV. The occurrence of Al?N bonding was identified at ion fluence higher than 5×10¹⁷/cm² at 396.6 eV. II–VI ZnO thin films were grown on an untreated/ion-beam-induced sapphire surface by pulsed laser deposition (PLD) for the investigation of the modified-substrate effect on photoluminescence. The ZnO films grown on modified sapphire containing Al?O?N bonding only, and both Al?O?N and Al?N bonding showed a significant reduction of the peak related to deep-level defects in photoluminescence. These results are explained in terms of the formation of Al?N?O and Al?O?N layers and relaxation of the interfacial strain between Al₂O₃ and ZnO.     

高温模具表面激光熔覆耐磨合金

用2kw CO 激光和送粉工艺,在4Cr5MoV_1Si 钢表面熔覆一层高温耐磨合金(Ni 基高温合金+WC),并应用于轧钢机导向板工作面。用扫描电子显微镜、电子探针和 x 射线衍射技术分别进行熔覆层的组织形态观察,微区成分分析和物相的鉴定。结果表明,熔覆层显微组织主要有许多弥散分布的 W_2C、(W,Ti)C_(1-x)、WC 和共晶态的 M_(12)C 及γ(f、c、c)母体相组成。室温及高温硬度测试结果表明,熔覆层有适中的室温硬度和相对较高的高温硬度。实际生产考核结果表明,激光熔覆导向板使用寿命大大提高,每对可轧钢1000～1100吨,而4Cr_5MoV_1Si 和普碳钢分别为400～500吨和200吨。     

数控铣镗床滑枕下垂补偿系统

提出了可行的数控落地铣镗床下垂补偿方案，使数控机床滑枕伸出时由于自重弯曲产生的精度误差得以修正。     

Solders development and application process for a micro chip-camera

Nowadays, micro components have to fulfill rising optical requirements for different scientific and industrial fields like astronomy, medicine or multimedia. For this purpose, advanced miniaturized chip-cameras are produced for the microsystems engineering market. The assembly and joining technologies play a very important role in the production of these micro components. Several challenges are associated with the joining of chip-cameras. In this study, the application of the soldering technology has been considered in order to face these challenges. Two joining technologies have been investigated: active soldering and transient liquid phase (TLP) bonding. Both soldering processes have shown a big potential for hybrid microsystems joining in previous studies. For both processes, soldering alloys and parameters have been conceived in order to fulfill the joining requirements of the micro camera components. For instance, the joining temperature represents a major challenge because the chip-camera consists of a plastic material, polymethyl methacrylate (PMMA). Therefore, particular attention has been directed to the soldering as well as to the coating temperature. The experimental investigations concerning the solders application through physical vapor deposition (PVD) have been supported by finite element method (FEM) simulations. The analysis of  the temperature distribution in the micro components during the coating process was the focus of  the calculations. Possible undesirable local overheated areas of the chip-camera components can be detected through simulation.

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Design of micromirror actuator by ionic polymer metal composites

Microactuators for micromirror system have found many applications in various areas including projection displays, optical switches, RF switches and so on. In this paper we demonstrated micromirror actuator using ionic polymer metal composites (IPMC) that is a suitable candidate, since it has many attractive qualities such as durability, aquatic, miniature and light-weighted. Specially, IPMC has extraordinary advantages which are simple bending motion for low driving voltage (1–2 V), low power consumption, and simple structure. The IPMC actuator is made of Nafion NE-1110 (Dupont Co, Ltd., 260 µm thick) layer and electrode (platinum) layers and driven by 1–4 V. The displacement measured vertically is 0.25 mm and tilting angle is 11.3°. The angular motion, which is more than 10°, is a good advantage in the field of display module. This paper shows that the IPMC actuator has enough possibility for other applications.