Carrier Density and Plasma Frequency of Aluminum Nanofilms

In this work, the prerequisite and mode of electromagnetic response of Al nanofilms to electromagnetic wave field was suggested.Reflectance, transmittance in infrared region and carrier density of the films was measured. With the carrier density of the films, the dependence of their plasma frequencies on the film thickness was obtained. On the other hand, the dependence of absorptance on the frequency of electromagnetic wave field was set up by using the measured reflectance and transmittance,which provided plasma frequency-film thickness relation as well. Similarity of both plasma frequency-film thickness relations proved plasma resonance as a mode of electromagnetic response in Al nanofilms.     

“低阻油层”的识别与认识

阿尔奇公式中的地层水电阻率R_w应有严格的使用条件。R_w选用不当是造成解释符合率降低的主要原因。"低阻油层"是一个不妥当的概念,在岩性、孔隙度相同的条件下,油层电阻率一定要比含同一矿化度地层水的水层电阻率高4倍左右,从这个意义上讲,"低阻油层"基本上是不存在的。所谓"低阻油层",大多数是由油层高矿化度和水层低矿化度的比较所产生的,两者相互依存,缺一不可,是陆相沉积油藏独有和一般现象。解决"低阻油层"的方法有两个:一是求得油层束缚水电阻率后经阿尔奇公式求得含水饱和度;二是不依靠地层水电阻率求地层含油饱和度。我国测井工作者独自研发的双频电阻率测井属于后者,目前已取得了很好的地质效果,正在一些油田推广使用。     

New methodologies for geological surveys

Within the context of Quaternary geology, current developments in the automation of survey data aim at mechanization of traditional data-handling techniques. In this type of automation, computer systems are asked to perform tasks at which they are slow, clumsy, and expensive. The need for continuous human support makes conventional automation unattractive.Traditional geological survey methodology has developed within the framework of manual data-handling techniques. The sampling design, data compression and generalization, the stratigraphic map all illustrate our inability to return to the only hard facts available: the observed boreholes and outcrops and their attributes.The computer can liberate us from most of these constraints. New sampling designs will be based on recent work in geostatistics. Information from existing archives may be captured through free-language processing, new borelogs will be recorded directly on magnetic medium. Lithological and stratigraphic interpretation will be automated and rely on numerical classification techniques. Traditional map drawing will disappear, the general purpose map will be replaced by special purpose univariate and multivariate maps computed directly from borelogs, but influenced by subjective point, line and area data.Experiments with the Quaternary by the Dutch geological survey are used to illustrate the feasibility of this alternative automation. The steps Input (free-language processing), Stratigraphic identification (interactive allocation), and Map construction (multivariate automated mapping) are illustrated.     

High-performance GaAs beam-lead mixer diodes for millimetre and submillimetre applications

A novel GaAs beam-lead Mott Schottky-barrier mixer device having a zero-bias junction capacitance near 10 fF, very low parasitic capacitance, ideality factor near or below 1.07, and a zero-bias cutoff frequency as high as 5000 GHz has been developed. The diode configuration makes use of a unique design in which the current distribution in the N+ layer at d.c. and at r.f. are equivalent, and thus, for the first time, it is possible to fully characterise mixer devices at d.c. Samples of these devices have been tested at 94 GHz in a broadband fin-line mixer structure, and realised a mixer conversion loss below 6.0 dB. This performance is representative of the best results achieved to date in a printed-circuit mount.     

高炉煤气与煤混烧的热电联产用流化床锅炉

介绍了以高炉煤气和劣质煤为燃料的热电联产用流化床锅炉的工作特性，阐述了为提高锅炉的燃烧效率和增强负调节能力所采取的关键技术。实际运行的情况表明：该种锅炉具有燃烧效率高，燃产适应性强，负荷调节性能好，节能效果明显和环保性能优越等优点，是冶金企业高效大量利用低热值高炉煤的敢的一种新炉型。     

基于神经网络的永磁同步电机矢量控制

本文提出了一种利用神经元PID的永磁同步电机矢量控制方案。给出了永磁同步电机的数学模型、神经网络PID结构、算法以及控制系统的仿真结果。仿真结果表明该系统具有良好的动态性能。     

国际工程项目融资概述

介绍了国际工程项目融资的概念和运作特点,从有限追索、风险共担等方面论述了项目融资与公司融资模式的差异,讨论了项目融资的不同模式及其特点,分析了项目融资的发展、现状及未来趋势。     

在EPSW2003中对地形图图廓的完善

为了便于测绘、使用和保管地形图,通常需要将其分幅和整饰,在EPSW2003系统中分幅和整饰虽然灵活方便,但图廓仍然存在一些不足之处。本文主要分析了存在的问题并利用模板控制技术对其进行完善。     

Separation and extraction of antimicrobial lipopeptides produced by Bacillus amyloliquefaciens ES-2 with macroporous resin

A new method for separation and extraction of antibiotic lipopeptides produced by Bacillus amyloliquefaciens ES-2 with macroporous resin was carried out in this study. Among widely used twelve macroporous resins, X-5 resin had the highest adsorption capacity in static and dynamic tests, its non-polarity and configuration were suited for the lipopeptides (surfactin and fengycin). Dynamic adsorption and desorption experiments were performed using a column packed with X-5 resin to obtain optimal conditions, with 30 g/L resin concentration, 0.5 BV/h feed flow rate, 80% aqueous ethanol at 1 BV/h elute flow rate as eluant agent, the total content of lipopeptides in final product was 79.5% (surfactin content was 33.2% while fengycin content was 23.4%), which had been improved about 150% compared with that of lipopeptide in fermentation broth. Because of its low cost, high efficiency, procedural simplicity and scale up ease, the adsorption–desorption method could be more efficient for the preparative separation and extraction of antibiotic lipopeptide than the conventional acid precipitation method, which could provide scientific references for antibiotic lipopeptide production.