RCS－Ⅰ反应堆堆芯模拟程序

本文介绍堆芯三维物理—热工水力耦台计算程序ＲＣＳ－Ｉ（ＲｅａｃｔｏｒＣｏｒｅＳｉｍｕｌａｔｏｒ）．其中子学模型采用先进的粗网格节块格林函数法，热工水力计算模型采用于通道分析方法．通过考虑多种反馈，该程序比较真实地描述堆芯的燃耗过程，具有临界、燃耗、中毒、跟踪和倒料等多种功能，可用于动力堆和研究堆的设计．     

用灵敏值确定纯β核素的液闪测量效率

纯β核素液闪测量技术应用广泛,实际工作中往往需要确定核素的测量效率;但除~3H、~(14)C等半衰期较长的核素外,多无系列猝灭标准源,给工作带来很多不便。本文根据国外有关方面研究,做了以~3H标准源为基准、通过理论计算求出其它纯β核素在均相条件下的测量效率和猝灭校正曲线,进而求得放射性的活度。本方法使用简便、结果可靠,实用性强。     

飞机撞击下高温气冷堆乏燃料厂房损伤研究

本文针对典型高温气冷堆乏燃料厂房在双发商用飞机撞击载荷下的响应及结构完整性开展研究,并探讨结构特性对撞击损伤的影响。对乏燃料厂房及飞机分别建立有限元模型,通过弹体-目标相互作用分析模拟了飞机撞击过程,综合IAEA与NRC的评价准则对乏燃料厂房在飞机撞击下的损伤程度进行评估。数值结果表明：厂房上对应于机身及发动机的撞击位置发生可接受的局部损伤;乏燃料贮存井墙体对于提高构筑物抗飞机撞击能力有重要作用。此外,构筑物外形对损伤有很大影响,圆柱形壳体的抗飞机撞击能力显著强于方形厂房,是核电厂厂房设计的优化方向之一。     

Cu(II)-Catalyzed Ortho-Selective Amination of Simple Phenols with O-Benzoylhydroxylamines

A Cu(II)-catalyzed ortho-selective amination of simple phenols with O-benzoylhydroxylamines has been developed, which provides access to 2-aminophenols under mild conditions. Various functional groups on the phenol and electrophilic amine are compatible, and the protocol typically delivers the products in moderate to good yields. The mechanistic detail of this process are discussed.     

Recycling of Polyethylene Bags into High-Strength Yarns Without Using Melt Processing

A critical issue facing mankind is how to effectively recycle plastic grocery bags. Currently, the most proven practice for bag recycling is to create numerous returning sites throughout the nation. However, the success is compromised by the voluntary nature of such activities. In this work, we investigate an alternative approach to bag returning, by diverting recycling activities directly to consumers or end users at home. Specifically, a simple process for converting waste bags into high-strength fibers and yarns is designed and tested in an experimental feasibility study. The results from tensile testing and thermal analysis demonstrate that by a combined process sequence of cutting, knotting, twisting, hot drawing, and heat setting, high-strength polyethylene yarns with mechanical properties comparable to those of melt-spun polyethylene fibers can be produced. Without the involvement of melt processing, yarns made of a waste high-density polyethylene grocery bag material were hot drawn and heat set to achieve a tensile strength of 330 MPa. Yarns with such ternacity are expected to find numerous applications in textile, flooring, and leisure products. This may open up a new paradigm in plastic bags recycling and allow part of the recycling burden to be shifted to local residential communities. POLYM. ENG. SCI., 60: 281–287, 2019. © 2019 Society of Plastics Engineers     

Degradation of the Tensile Properties of an Au-Coated 316L Stainless Steel Bipolar Plate in a Fuel Cell Stack

Cost reduction for fuel cell stainless steel bipolar plate (BPP)’s Au-coating requires in depth understanding of its corrosion behavior. To this end, this paper explores the degradation of the tensile properties of an Au-coated 316L stainless steel bipolar plate in a real fuel cell stack. 4 BPPs were randomly chosen and removed from a stack that had run for 1600 h and, along with 2 pristine BPPs, were subsequently tested for surface morphology and tensile properties. Results suggest that (1) Pristine BPPs have initial pinhole flaws on the surface, whereas corroded BPPs have punctate (on O₂ side) and continual (on H₂ side) corrosions. (2) The tensile ultimate elongation for a BPP significantly decreases after corrosion on both O₂ and H₂ sides. (3) The degradation of tensile properties is attributed to primary cell effect.

     

Efficient key generation leveraging channel reciprocity and balanced gray code

Wireless Networks - Key generation leveraging wireless channel reciprocity can establish secret keys from unauthenticated broadcast channels and thus protect the communication of wireless networks....     

Low complexity carrier phase estimation for m-QAM optical communication systems

Photonic Network Communications - A low complexity carrier phase estimation (CPE) algorithm for M-ary quadrature amplitude modulation (m-QAM) optical communication systems is investigated in this...     

A holographic waveguide based eye tracking device

We demonstrated the feasibility of using a holographic waveguide imager for eye tracking. A holographic waveguide placed in front of the eye was used to capture images of the anterior segment of the eye and to guide the images to a camera distant from the eye. The pupil centre (PC) and corneal reflection (CR) of the eye was used to compute eye position. A custom-built model eye was used to validate the prototype eye tracker. A linear relationship between the angular eye position and the PC/CR vector was found over 60 horizontal degrees and 40 vertical degrees. The tracking accuracy and precision were 0.72 degree and 0.50 degree over these tracking ranges. These results confirmed that holographic waveguide could be a viable platform for developing compact, wearable, see-through eye trackers that can continuously monitor eye movements during real life tasks and thus can facilitate diagnosis of oculomotor disorders.