Spatial distribution of laser energy and its influence on the stability of extreme narrow keyholes during ultra-high power laser welding

The instability of extremely narrow keyholes is the main challenge in high-power laser welding.In this work,the spatial energy distribution and its influence on the stability of extremely narrow keyholes during ultra-high power laser welding are studied.A multiphase flow model that considers the vapor plume impact and the multiple scattering of laser radiation is built to simulate the topology and downstream wave flow on the keyhole wall.Drastic keyhole fluctuation is due to excessive energy acc...     

Untraceable Analysis of Scalable RFID Security Protocols

Wireless Personal Communications - In order to support robust implementation of IoT, many schemes have been done to provide privacy, anonymity, scalability and customizability. Ray et al.’s...     

一种多级混沌同步通信系统

本文了蔡氏混沌同步通信系统的主要性质和局限性,提出了一种多级混沌安全通信系统,证明了该系统对传输信号可以完全重建,在有效带宽,失真特性及安全性和方面获得了改善。文中出了给利用该系统进行语音数据和静止图像数据传输的实例。     

A Novel Human Antibody,HF, against HER2/erb-B2 Obtained by a Computer-Aided Antibody Design Method

Fully human antibodies have minimal immunogenicity and safety profiles. At present, most potential antibody drugs in clinical trials are humanized or fully human. Human antibodies are mostly generated using the phage display method (in vitro) or by transgenic mice (in vivo); other methods include B lymphocyte immortalization, human–human hybridoma, and single-cell polymerase chain reaction. Here, we describe a structure-based computer-aided de novo design technology for human antibody generation. Based on the complex structure of human epidermal growth factor receptor 2 (HER2)/Herceptin, we first designed six short peptides targeting the potential epitope of HER2 recognized by Herceptin. Next, these peptides were set as complementarity determining regions in a suitable immunoglobulin frame, giving birth to a novel anti-HER2 antibody named “HF,” which possessed higher affinity and more effective anti-tumor activity than Herceptin. Our work offers a useful tool for the quick design and selection of novel human antibodies for basic mechanical research as well as for imaging and clinical applications in immune-related diseases, such as cancer and infectious diseases.     

Brazil’s Petrobras Keen on Cooperation with China

Brazil’s state-controlled oil and gas giant Petrobras is analyzing future cooperation opportunities with Chinese companies,the company’s CEO Jose Sergio Gabrielli said in an interview with Xinhua in Rio de Janeiro in late     

Improve on/off ratio of organic heterojunction transistors by adopting single-sandwich configuration

Organic heterojunction transistors (OHJTs) based on 5,5′″-bis(naphtha-2-yl)-2,2′:5″,2′″-quaterthiophene (NaT₄)/copper-hexadecafluoro-phthalocyanine (F₁₆CuPc) heterojunction were fabricated in single-sandwich and sandwich configurations, respectively. All the devices operated in depletion-accumulation (normally-on) mode. High field-effect mobility of 0.35 cm²/Vs was obtained for all devices, which was higher than that, 0.20 cm²/Vs of the devices with NaT₄ as active layer. The on/off ratio of 1 × 10⁵ was obtained for OHJTs with single-sandwich configuration, which is three orders of magnitude higher than that of OHJTs with sandwich configuration. Compared with OHJTs with sandwich configuration, the higher on/off ratio was mainly determined by the lower off state current in OHJTs with single-sandwich configuration. In OHJTs with single-sandwich configuration, the well-type shield effect of the source and drain electrodes caused a very narrow empty region in F₁₆CuPc film, which is responsible for the lower off state current.     

窄带物联网技术在铜冶炼工厂中的应用实践及前景展望

在江西铜业股份有限公司贵溪冶炼厂智能工厂建设一期项目中,窄带物联网技术首次被成功应用于铜冶炼的能源计量与安全环保等监测系统,其广覆盖、低功耗、低成本的技术优势初步显现。通过对铜冶炼全流程中现有的参数指标监控需求与环境进行剖析,结合窄带物联网的优势特性,遴选出几例契合度高的典型应用,对其可行性展开分析探讨,旨在拓宽此项技术在铜冶炼过程中的应用思路。     

FF和PROFIBUS现场总线控制系统应用

通过对FF和PROFIBUS现场总线综述,介绍基于FF和PROFIBUS现场总线技术的烟气海水脱硫控制系统在1 000MW火电机组的应用。就地变送器、流量液位表计等采用具有FF接口的产品,部分电动执行机构具有PROFIBUS-DP的接口。具有现场总线接口的仪表设备通过总线通信与艾默生OVATION系统连接。应用实践表明,基于FF和PROFIBUS现场总线技术的烟气海水脱硫控制系统运行稳定,现场总线技术的优势得到体现。     

SAR测雨反演算法MREA的研究

介绍了利用X-SAR的归一化雷达散射截面(NRCS)来反演地表降雨量的算法:改进型回归经验算法(MREA),依据测雨反演算法的基本原理,重点分析了MREA算法的理论依据,对于矩形降雨分布在地表降雨量R=50 mm/h和R=100 mm/h的条件下用MREA算法进行反演,指出了NRCS随x轴坐标不断变化这一导致MREA算...