变象管、双近贴象增强器及带微通道板光电倍增管的快门选通电路

本文主要简介我国变象管、双近贴象增强器毫微秒分幅相机的研制现状,并讨论这些相机的快门脉冲发生器电路。同时还介绍了用于带微通道板光电倍增管的选通电路。这些电路作适当修改后可用于微光硅靶摄象管的控制,高压电器特性试验,毫微秒脉冲源以及激光调制等场合中。     

A kHz heat‐load shutter for white‐beam experiments at synchrotron sources

A heat‐load shutter capable of frequencies from one to several tens of kHz and window times from 10 µs up to 1 ms is described. In the current configuration the water‐cooled shutter absorbs ～99% of the heat generated by the white beam. It has been successfully used for extended periods synchronized with a Jülich pulse‐selector operating at 946 Hz. The temperature of the pulse‐selector remained constant during a three‐day continuous operation. Flexibility is provided by the interchangeability of the chopper disc.     

基于CMOS图像传感器多斜率光积分的研究

基于CMOS图像传感器IBIS5-A-1300驱动时序，对多斜率光积分进行了研究，并实现同步快门模式下的多斜率光积分．选用CPLD器件作为硬件设计载体，使用VHDL语言对时序发生器进行了硬件描述．采用QutartusⅡ软件对所作的设计进行了功能仿真．实验结果表明，多斜率光积分有效扩展了普通线性转移成像器的光学动态范围．     

CE combined with rolling circle amplification for sensitive DNA detection

Here we describe an assay which combines CE with rolling circle amplification (RCA) for sensitive DNA detection and quantification. RCA is an isothermal DNA replication technique that generates a long ssDNA with tandem repeats. It requires simpler temperature control in reaction and offers higher sequence specificity and greater quantitation capability compared to other amplification technologies. In this study, RCA amplified the DNA target via a circular template, and the product was digested into monomers for CE analysis. Less than 2 fmol of the DNA target could easily be detected using this RCA-CE assay and the assay has a dynamic range of two orders of magnitudes. Moreover, simultaneous detection of both the target DNA and the internal standard was achieved by designing two padlock probes with different sizes, which could significantly improve the quantification accuracy. The RCA-CE assay is easy to perform, readily adaptable for detection of multiple targets because of the high resolution power of CE, and is compatible with other applications employing RCA as a signal amplification tool. Additionally, this assay can be used with a capillary array system to perform sensitive, high-throughput genetic screening.     

滚动轴承声信号特征提取和诊断试验研究

为解决振动检测方法不能有效识别低速旋转机械滚动轴承故障问题,利用声发射检测方法,建立了滚动轴承低速声发射信号采集试验装置,对模拟人工缺陷滚动轴承声发射信号进行了采集,进而对滚动轴承声发射信号进行总体平均经验模式分解,结合能量矩及相关系数法综合判断分解后各模态分量的真伪,据此提取出特征信号并做出其局部Hilbert边际谱,最后对滚动轴承各种故障模式进行诊断。试验结果表明该诊断方法能准确识别滚动轴承声发射信号故障频率,依据特征频率及幅值大小可对低速滚动轴承故障进行有效诊断。     

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介绍了HL-2M装置极向场线圈所需的大截面外方内圆铜导体的规格,用二辊周期式轧管机进行冷轧的工艺技术以及所做的多项检测.用这个技术制造了具有冷却水孔道的大截面外方内圆铜管.测试结果表明,该工艺生产的外方内圆铜管在尺寸及各项性能上均满足HL-2M托卡马克装置极向场线圈的加工要求.     

Mid-wave infrared liquid crystal shutter for breathalyzer applications

There exists a problem with an in situ diagnostics of contamination of ethyl alcohol in a human being exhaled air. When ethyl alcohol in a mouth blowing (in a gaseous state) exists, the characteristic CH stretch absorption bands in CH₃ and CH₂ functional groups in ethanol (CH₃CH₂OH) appear at a wavelength of λ = 3.42 μm. To investigate the presence of ethyl alcohol in exhaled human air, the light beam of λ = 3.42 μm is passing through an air sample. If one alternately measures the intensity of the investigated beam and the reference, a percentage of ethanol in the air sample can be estimated using a sensitive nondispersive infrared (NDIR) system with a stable operating flow mass detector. To eliminate a mechanical chopper and noise generating stepper motors, a photonic chopper as a liquid crystal shutter for λ = 3.42 μm has been designed. For this purpose, an innovative infrared nematic liquid crystal mixture was intentionally prepared. The working mixture was obtained by a selective removal of CH bonds and its exchange by heavier polar substituents, what ensures a lack of absorption band of CH bonds. The paper presents theory, concept and final experimental results of the infrared nematic liquid crystals mixture and the liquid crystal shutter for breathalyzer applications.     

CICC导体轧制过程有限元模拟

利用显式动力学有限元分析软件ANSYS/LS-DYNA对CICC导体的轧制过程进行了模拟,得到了导体在不同轧制道次中所需的轧制力以及轧制道次对导体形状和残余应力的影响。轧制力的计算结果与参考的实验数据吻合,能为导体轧制成型设备的研制提供依据。     

Aptamer-conjugated bio-bar-code Au–Fe3O4 nanoparticles as amplification station for electrochemiluminescence detection of tumor cells

An electrochemiluminescence (ECL) assay has been developed for highly sensitive and selective detection of tumor cells based on cell-SELEX aptamer-target cell interactions through a cascaded amplification process by using bio-bar-code Au–Fe₃O₄ as amplification station. Firstly, bio-bar-code toehold-aptamer/DNA primer/Au–Fe₃O₄ (TA/DP/Au–Fe₃O₄) nanoconjugates are fabricated with a ratio of 1:10 to efficiently avoid cross-linking reaction and recognize target cells, which are immobilized on the substrate by hybridizing aptamer to capture probe with 18-mer. Through strand displacement reaction (SDR), the TA/DP/Au–Fe₃O₄ composites further act as the amplification station to initiate rolling circle amplification (RCA). As a result, on the surface of TA/DP/Au–Fe₃O₄, a large number of Ru(bpy)₂(dcbpy)NHS-labeled probes hybridize to RCA products, which are easily trapped by magnetic electrode to perform the magnetic particle-based ECL platform. Under isothermal conditions, this powerful amplification strategy permits detection of Ramos cells as low as 16 cells with an excellent selectivity. Moreover, analysis of Ramos cells in complex samples and whole blood samples further show the great potential of this ultrasensitive approach in clinical application involving cancer cells-related biological processes.