同步辐射光刻技术

同步辐射光刻有希望代替传统光刻技术,用于0.25μm以下图形的超精细加工。本文叙述了它的原理、相关技术的开发现状和工艺应用。     

Improved cellulase production by stable Clostridium cellulolyticum mutants

Methods for the production of mutants of the cellulase producer Clostridium cellulolyticum ATCC 35319 were examined using an agar plate screening technique. Spontaneous and UV light-induced mutants were isolated, some of which exhibited a high level of both endoglucanase and exoglucanase activities as assayed using CMC (carboxymethyl cellulose) and PNPCb (paranitrophenyi-β-cellobioside) respectively. The volumetric enzyme activities were up to 2.5 times those of the wild strain.     

近程地对地战术导弹的作用与问题

海湾战争中,“爱国者”导弹成功地拦截了“飞毛腿”导弹,给近程地对地战术导弹的作用、发展与装备方向提出了值得思考的问题。本文着重讨论在局部战争中,近程地对地战术导弹的作用、使用场合及其技术发展方向。     

光测遥测数据联合计算速度的方法

提出了利用遥测的过载、俯仰角信息和光测的坐标联合计算弹道关机段速度的方法，从遥测结果的系统误差、随机误差和数值积分的截断误差三万面对剩余误差的影响进行了精度分析，并给出了速度精度的算法。     

采用多模复合导引头提高反舰导弹突防能力

分析了现有反舰导弹制导体制的特点，提出了反舰导弹如采用被动微波／红外成像双模复合导引头，将是提高其突防能力的有力举措，同时提出了研制主被动／红外成像三模复合导引头的建议，并给出了三模导引头结构布局示意图。     

Synthesis and characterization of radiation grafted copolymer for removal of nonionic organic contaminants

Nonionic organic contaminants such as phenol, benzene, and toluene from contaminated wastewater on laboratory scale can be effectively sorbed by cellulosic wood pulp sheet incorporated with three polar functional groups. The synthesis was carried out by graft copolymerization reaction of N,N‐dimethylaminoethylmethacrylate with methacrylic acid onto wood pulp. The preparation conditions at which the grafting process proceeds homogeneously are determined. Characterization and some selected properties of the original and grafted wood pulp were evaluated using FTIR and scanning electron microscope, also, the removal of phenol, benzene, and toluene on laboratory scale was investigated by using gas chromatography. It was found that phenol shows the highest removal percent than that of benzene and toluene. The efficiency of removal of the nonionic contaminants is found to be 97%, which shows a great promise for its applicability in the removal of organic contaminates from wastewater. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3589–3595, 2006     

Analysis of hazard area associated with hydrogen gas transmission pipelines

Hydrogen is considered to be the most important future energy carrier in many applications reducing significantly greenhouse gas emissions, but the safety issues associated with hydrogen applications need to be investigated and fully understood to be applicable as the carrier. Generally, the locations of hydrogen production and consumption are different. Hydrogen must be transported from the point of production to the point of use. Pipeline delivery is cheaper than all other methods for large quantities of hydrogen. The rupture of a hydrogen pipeline can lead to outcomes that can pose a significant threat to people and property in the immediate vicinity of the failure point. In this work, a simplified equation of hazard analysis is proposed for the pipeline transporting hydrogen, which relates the diameter, the operating pressure and the length of the pipeline to the size of the affected area in the event of a failure of the pipeline. The dominant hazards are thermal radiation from sustained fire and shock pressure from gas cloud explosion. For a transmission pipeline of hydrogen gas, the hazard area from the fire is slightly larger than by the other event. The hazard area is directly proportional to the operating pressure raised to the power one-half, and to the pipeline diameter. This simplified equation to estimate the hazard area will be a useful tool for safety management of hydrogen gas transmission pipelines.     

PV system sizing using observed time series of solar radiation

Sizing represents an important part of photovoltaic system design. This paper describes a sizing procedure based on the observed time series of solar radiation. Using a simple geometrical construction, the sizing curve is determined as a superposition of contributions from individual climatic cycles of low daily solar radiation. Unlike the traditional methods based on loss-of-load probability, the reliability of supply enters in this method through the length of the time series of data used in the analysis. The method thus resembles techniques used in other branches of engineering where extreme values are considered as functions of certain recurrence intervals.     

EXPERIMENTAL RESEARCH ON RADIATION FROM DOUBLE CYLINDRICAL STRUCTURES

1. INTRODUCTION Induced by unbalanced mechanical forces and moments, underwater structures vibrate and radiate The main form of underwater structures, such a submarine, is reinforced double cylindrical structure immersed in water, with fluid media filled between th double cylindrical shells. In essence, this is a coupling problem between fluid and structure. Multipl methods have been used to estimate radiation leve from underwater structures[1-9]. Musha[10] and Chertock[11] estimate the …