A study on performance characteristics of granular-media trickling filters

Mass transfer within microbial films is described using Monod type biological kinetics in terms of the properties of packing material and the feed solution. For this purpose computer techniques have been first developed for the numerical evaluation of the normalized biofilm mathematical model. A second-order partial differential equation describing the mechanism of dispersion phenomena inside the liquid layer is then solved to determine the mass transfer coefficient. The application of the theory to experimental data reported in literature has also been demonstrated using the values of mass transfer coefficients and the computer programs developed.     

金刚石膜在Si(100)衬底上的选择沉积

采用自行设计的微波等离子体化学气相沉积系统,利用铜网作为模板实现了在Si(100)衬底上金刚石膜的选择沉积.用场发射扫描电子显微镜(SEM)、Raman散射谱对样品进行了表征与分析.并与同样生长条件下未采用模板时得到的金刚石样品进行了比较.结果发现,采用模板后,金刚石膜的成核密度和质量都得到很大提高.     

CVD金刚石薄膜涂层衬底预处理方法

概述了CVD金刚石薄膜涂层衬底预处理的基本方法,并对一些主要方法作了评述.对于硬质合金类衬底预处理、铜衬底表面预处理、钢铁衬底表面预处理、硅表面预处理,提高膜基结合力的途径除有研磨、超声清洗、植晶、化学腐蚀、等离子体刻蚀、沉积中间过渡层等方法外,还有优化衬底形状、通过表面扩散感应促进成核等手段.     

Behavior of the continuous X-ray background in grazing-exit electron probe X-ray microanalysis

The energy distribution of the background radiation originating from two kinds of substrate materials has been studied using Electron Probe X-Ray Microanalysis (EPMA) at grazing-exit angles. The different behavior between tendencies of background reduction for the silicon and the gold substrates at the grazing exit angle is explained using a critical energy concept. It is also shown experimentally that a gold substrate results in a lower background intensity than a silicon substrate in the energy region 5–7 keV, while on the other hand, for elements with X-ray lines of 2–3 keV, it is advantageous to perform the analysis when such elements are deposited on the silicon substrate.     

陶瓷微细镀覆新技术的研究

建立微机处理体系(包括线路、图形设计,光照点选择及活化处理等)与化学镀铜相结合的微细镀覆新技术.该技术可在Al2O3基底上获得性能良好的Cu镀层,其布线速率达 50mm/s,线分辨率 35μm,工艺简便,条件温和,为陶瓷微细镀覆开辟了新途径.     

模拟生物矿化过程原位合成活性纳米碳酸钙

生物矿化是一种广泛而复杂的固液之间、有机物和无机物间的物理化学过程．以少量有机质为模板,进行分子操作,高度有序地组合成无机材料．有机基质能作为构造支持的惰性底质或矿物沉淀的局限空间和核化作用的表面,确定矿物质点的形态大小、空间排列、结晶取向和同质多晶类型,并与生物晶体一起确定生物矿物硬体的机械性质．     

The Electrochemical Activity Determination of γ-Glutamyl Transpeptidase

Abstract

The electrochemical activity determination of γ-glutamyl-transpeptidase is described using the electrogenic L-γ-glutamyl paraaminodiphenylamide substrate. In order to correlate the results with classical measurements involving chromogenic substrates, linear calibration curves for the amperometric detection of the released free amine, the kinetics of the catalysis and the enzyme level in one plasma sample have been compared to photometric experiments effectuated in parallel runs, in the same conditions, with L-y-glutamyl paranitroanilide as the substrate. Results show that this new technique applies successfully to such evaluations.     

Retention of poly(N-isopropylacrylamide) thin films on polycarbonate via polymer interdiffusion

This study explored the possibility of polymer interdiffusion for retaining thermoresponsive poly(N-isopropylacrylamide) (pNIPAAm) on polycarbonate (PC). It was hypothesized that interdiffusion could be facilitated either by increasing the annealing temperature or by treating PC using air plasma (AP) and ultra-violet ozone (UVO). The results showed that increasing annealing temperature only moderately improved pNIPAAm retention. Treating PC with AP led to an increase in surface-active groups and a greatly enhanced retention of pNIPAAm. UVO treatment, however, severely damaged the PC layer with no noticeable enhancement on pNIPAAm retention. The retained pNIPAAm films on PC exhibited thermoresponsive behavior as evidenced by water contact angle and desired cell attachment/detachment behaviors. These results illustrate the simplicity of using polymer interdiffusion to successfully retain pNIPAAm films on a polymer, and the resulting substrates would be less expensive and more versatile than those retained on brittle supports (e.g., glass) for applications that require resilient thermoresponsive substrates.     

Cetyltrimethylammonium Bromochromate: A New and Efficient Oxidant for Organic Substrates

Cetyltrimethylammonium bromochromate is a versatile reagent for the effective and selective oxidation of organic substrates, particularly for alcohols, under mild conditions.     

Enzyme-mediated enantioselective hydrolysis of soluble polymer-supported dendritic carbonates

The easy separation of optically active compounds from enzymatic kinetic resolution products by simple precipitation using poly(ethylene glycol) (PEG)-supported dendritic carbonates is disclosed. The water-soluble polymer-supported substrates were prepared by immobilization of (±)-1-phenylethanol onto a monomethoxy PEG (MPEG; av MW 5000) bearing a dendritic spacer through a carbonate linker. The enantioselective hydrolysis of the dendritic substrates of the 1st and 2nd generations using lipase from porcine pancreas (PPL; Type II, Sigma) smoothly proceeded, and a multimolecule of the corresponding (R)-alcohols was released from one molecule of the racemic substrates. The E values of the reactions at 0 °C in a mixed solvent (hexane/buffer = 9/1) were up to >200.