高能大功率电子辐照加速器270°偏转光路设计

为实现高能大功率电子辐照加速器的一机多用目的,需研制270°偏转光路支线。本文采用Trace3D程序对270°偏转光路进行了设计与模拟计算,设计了双135°偏转磁铁和整体270°偏转磁铁。对双135°和整体270°两种偏转磁铁元件进行二维和三维电磁场设计与模拟计算,计算结果表明,整体270°偏转磁铁的场分布与光路设计中所要求的物理参数差距较大。由于整体270°偏转磁铁的场分布调整较困难,使工程实施中的束流调试难度较大,因此采用双135°偏转磁铁的光路方案。     

Effect of Pre-heat and Inert Gas Species on Cryogenic Aerosol Cleaning Performance in Semiconductor Manufacturing

Cryogenic aerosol cleaning is a dry cleaning method used in the back end of line (BEOL) semiconductor manufacturing to remove defects from planar hydrophobic surfaces such as SiCOH and SiCxNyHz. Cryogenic aerosol cleaning is preferred over conventional wet cleaning methods as it is a non-contact cleaning method, which uses inert gases to generate sub-micrometer-sized solid aerosol particles that physically remove nanometer-sized contaminants on wafer surfaces. Particle removal mechanism involves detachment of the particles upon impact with aerosol, diffusion, and finally entrainment away from the wafer. In BEOL metal line patterning, particles on the dielectric isolation surfaces translate through the subsequent lithography and copper fill steps in to single or multiple metal line open defects that are yield killers. In this study, we show that the particle removal performance of the standard aerosol cleaning can be enhanced by pre-heating the wafer and use of a higher molecular weight inert gas, namely Ar, for aerosol generation. Both the addition of a Pre-heat step and the use of Ar as the aerosol source showed 47–52% reduction in single and multiple line opens detected through wafer electrical tests during high volume semiconductor manufacturing process.     

LNG储罐工程用低温钢筋机械连接接头研发初探

综合考虑LNG储罐工程的特点以及耐-165℃的低温钢筋的力学性能,根据钢材的低温性能规律和钢筋机械连接的传力机理,设计低温钢筋镦粗直螺纹接头。按照相关标准进行了一系列低温钢筋和低温钢筋接头的常温和-165℃低温加载试验,接头试件各项试验结果均满足要求。最后根据实际情况对低温钢筋接头提出了更高的要求,并给出了实现方案。研究成果可为LNG储罐工程低温钢筋机械接头的研发和国内相关标准的制定提供参考。     

低温氢泄漏及射流火传播特性研究现状

阐述了低温氢的应用前景及泄漏危险性,从气体扩散特性和射流火点火、传播行为两方面介绍了低温氢泄漏的研究现状,对低温氢泄漏气体扩散及射流火传播特性的研究方法、手段及结论进行了总结分析。目前,低温氢泄漏研究方法包括实验研究和数值模拟,多数研究集中在气体扩散特性,对射流火的点火、传播行为的产生条件及影响因素尚不明确。未来应完善低温氢泄漏气体扩散预测模型,以建立有效的低温氢泄漏气体扩散过程及射流火点火、传播预测模型。     

双波长红外激光诱发痛觉刺激研究

搭建红外波段双波长(1940 nm和980 nm)激光诱发痛觉刺激系统,探索基线温度控制、激光吸收导热涂层、致痛区域控制对痛觉刺激效果的影响。利用热电偶测温模块实时监测基线温度控制及涂抹20%氧合血红蛋白溶液时离体猪皮皮肤表面温度的变化;利用滤光片实现致痛区域控制。利用1940 nm激光模块实现了40℃基线温度控制,结合980 nm脉冲激光模块完成了联合痛觉刺激实验;皮肤表面涂抹20%氧合血红蛋白溶液时温降时间(110 ms)远低于空白对照(1.2 s)和风冷散热(341 ms),可提升痛觉信号质量;列举了三种不同尺寸滤光片下的温度场分布情况,证明了致痛区域的可控性。双波长红外激光诱发痛觉系统提出的三种技术对痛觉刺激效果有较好的促进作用,证明了这种痛觉刺激模式的可行性和可信性。     

Dynamic response of ferrofluidic deformable mirrors using elastomer membrane and overdrive techniques

The experimental results obtained with a ferrofluidic deformable mirror controlled by electro-magnet actuators are presented here. Using a step input through a single actuator, we obtained a steady-state settling time of 100?ms; however, different combinations of overdrive inputs can be used to decrease it to 25?ms. A new technique which consists of laying down an elastomer membrane, coated with an aluminum film, on the ferrofluid is also discussed. By adding the membrane on the ferrofluid, it further decreases the time response by a factor of 2. Furthermore, the thin aluminum layer improves the reflectivity of the mirror. Finally, using the membrane and the overdrive techniques combined, the time response is improved by a factor of 20. Numerical simulations show that ferrofluidic mirrors using membranes and improved electronics should reach settling times of the order of a millisecond. Presumably, even lower settling times could be possible.     

The influence of cryogenic rolling on a transformation-induced plasticity steel

ABSTRACT

Here, a novel cryogenic rolling plus intercritical annealing process was applied to a transformation-induced plasticity (TRIP) steel with a low chemical composition of carbon and manganese. Compared with traditional cold rolling, obvious grain refinement was observed, due to a high amount of dislocations retained. In addition, austenite volume fraction was increased, because of a unique nucleation mechanism. Subjected to cryogenic rolling, strength and ductility were increased, due to the enhanced austenite stability, which provided continuous and active TRIP effect. Consequently, tensile strength was increased to 1030?MPa, and elongation was increased to 38.2%. Thus, a great mechanical combination was obtained in a steel with a relatively low chemical composition with carbon and manganese, only by cryogenic rolling process.     

Luminescence at 2.8 μm: Er3+-doped chalcogenide micro-waveguide

This paper reports the fabrication of luminescent optical rib/ridge waveguides made of erbium doped Ga-Ge-Sb-S films deposited by RF magnetron sputtering. Several fluorescence emissions of Er³⁺ ions from the visible to the middle infrared spectral domain were clearly observed within the films. The study of the ⁴I_13/2 level lifetime enabled development of a suitable annealing treatment of the films to reach the value of the bulk counterpart while the variation in surface roughness was limited, thus ensuring reasonable optical losses (0.7–0.9 dB/cm). Amplification experiments were carried out at 1.54 μm leading to complete characterization of the erbium-doped micro-waveguide with ∼3.4 dB/cm on/off gain. A demonstration of mid-IR photoluminescence from Er³⁺-doped chalcogenide micro-waveguide was recorded at ∼2.76 μm. The multi-luminescence from the visible to mid-IR generated using erbium doped chalcogenide waveguiding micro-structures might find easy-to-use applications concerning telecommunication technologies or on-chip optical sensors for which luminescent sources or amplifiers operating at different wavelengths are required.