共查询到20条相似文献,搜索用时 359 毫秒
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介绍用激光诱发分子荧光法探测流动液体中单个染料分子的基本原理和实验方法。并给出用自行设计和研制的单分子探测谱仪分析R6G水溶样品的最新实验结果。 相似文献
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流动液体中单个分子探测技术的基本原理及实验方法 总被引:2,自引:2,他引:0
介绍用激光诱发分子荧光法探测流动液体中单个染料分子的基本原理和实验方法。并给出用自行设计和研制的单分子探测谱仪分析R6G水溶液样品的最新实验结果。 相似文献
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激光单分子探测技术的研究 总被引:7,自引:1,他引:6
文中介绍利用激光激发分子荧光的方法探测液体中单个染料分子的新技术,以及作者自行设计和研制的激光单分子探测谱仪。通过探测“光子爆发”,把单个染料分子的荧光同很强的背景杂散光区别开来。进一步用82MHz高重复频率的锁模激光器和时间门符合技术,成功地消除了Raman散射光。目前该谱仪达到的检测限为灵敏区内仅有~7个R6G分子。 相似文献
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介绍采用双光子激发荧光方法进行单分子探测的原理和自行研制的实验装置,激发光聚焦和荧光收集采用共焦方式。选择香豆素C445水溶液作为研究对象,从样品流速、浓度、激光功率、信噪比和检测限等方面探讨了双光子激发荧光的特性。该谱仪目前己达到探测灵敏区内C445的平均分子数为1.5个的检测限 相似文献
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We report studies on the multiple ionization of the N2 molecule using intense, femtosecond laser pulses. We present details of the experimental characterisation of the light pulses
and analysis and detection of the ions produced. Precautions to be taken in intense field ionization experiments are discussed.
We illustrate the retrieval of information about different aspects of the ionization process (such as, kinetic energies of
the fragments produced, dissociation bond lengths and information on the precursors to fragmentation) using coincidence techniques.
We report results of the first measurements of the angular distribution of a highly charged fragment, N3+. 相似文献
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Shiltsev V Alexahin Y Bishofberger K Kamerdzhiev V Kuznetsov G Zhang XL 《Physical review letters》2007,99(24):244801
We report the successful application of space-charge forces of a low-energy electron beam for improvement of particle lifetime determined by beam-beam interaction at a high-energy collider. In our experiments, an electron lens, a novel instrument developed for the beam-beam compensation, was set on a 980-GeV proton bunch at the Fermilab Tevatron proton-antiproton collider. The proton-bunch losses due to its interaction with the antiproton beam were reduced by a factor of 2 when the electron lens was operating. We describe the principle of electron lens operation and present experimental results. 相似文献
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D L Miller 《Ultrasonics》1984,22(6):261-269
An ultrasonic instrument for the accurate measurement of bolt stress is described. The instrument, which is based on the pseudo-continuous-wave technique, uses carrier phase detection to track the frequency of the mechanical resonance of the bolt. The basic operation of the instrument and the experimental results obtained are discussed. 相似文献
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Ultrasonic instrument for measuring bolt stress 总被引:1,自引:0,他引:1
An ultrasonic instrument for the accurate measurement of bolt stress is described. The instrument, which is based on the pseudo-continuous-wave technique, uses carrier phase detection to track the frequency of the mechanical resonance of the bolt. The basic operation of the instrument and the experimental results obtained are discussed. 相似文献
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A.G. Berezin O.V. Ershov A.I. Nadezhdinskii 《Applied physics. B, Lasers and optics》2002,75(2-3):203-214
The goal of the present paper was to develop an experimental technique to detect trace concentrations of complex molecules
in the atmosphere using near-IR diode lasers. Ethanol and propane were chosen as model species. New optical, hardware, instrument-operation-mode
and data-processing approaches for detection of trace complex molecules were developed. Different physical processes limiting
the sensitivity of trace molecule detection were considered and solutions were developed to reduce the influence of these
mechanisms on instrument operation. An absorption sensitivity of αmin=2.5×10-5 for 4.5 ms measurement time was achieved, which is comparable with the sensitivity of “small” molecule detection. The first
results utilizing this technique for in-field monitoring of trace complex molecules are presented.
Received: 25 April 2002 / Revised version: 29 May 2002 / Published online: 21 August 2002
RID="*"
ID="*"Corresponding author. Fax: +7-095/135-8281, E-mail: anber@nsc.gpi.ru 相似文献
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K. Ravi S. Lee A. Sharma G. Werth S. A. Rangwala 《Applied physics. B, Lasers and optics》2012,107(4):971-981
We report an experimental apparatus and technique which simultaneously traps ions and cold atoms with spatial overlap. Such an apparatus is motivated by the study of ion–atom processes at temperatures ranging from hot to ultra cold. This area is a largely unexplored domain of physics with cold trapped atoms. In this article we discuss the general design considerations for combining these two traps and present our experimental setup. The ion trap and atom trap are characterized independently of each other. The simultaneous operation of both is then described and experimental signatures of the effect of the ions and cold atoms on each other are presented. In conclusion, the use of such an instrument for several problems in physics and chemistry is briefly discussed. 相似文献
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We tested a handheld X‐ray fluorescence instrument with adaptable matrix correction for its suitability in meteoritics. We report here the instrument setup, precision and accuracy and present examples of applications. With a measuring time of 300 s, it is possible to collect accurate data for K, Ca, Ti, Cr, Mn, Fe, Co, Ni, Sr and Ba that are needed for the identification of doubtful meteorites and the nondestructive classification of chondrites and achondrites. The factory‐supplied calibration curve of the instrument was fine tuned for our purposes with the use of well‐analyzed meteorite powders, pressed pellets and meteorite hand specimens as standards. Relative errors of 10% to 20% are reached for the mentioned elements. The instrument was tested in the hot desert of Oman while searching for meteorites and also in the laboratory while doing research on meteorites. The main applications of the instrument are the identification and classification of meteorites, the quantification of terrestrial elemental contamination (Sr and Ba) and detection of Mn‐rich desert varnish. It is possible to discriminate the major meteorite groups using Fe/Mn and Ni values. Handheld X‐ray fluorescence is also useful in identifying meteorites belonging to the same fall event. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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基于机器视觉构建汽车仪表自动检测系统已成为实现仪表生产测试的主要途径。基于图像空间到参数空间的收敛映射提出了改进CM-Hough变换检测算法对汽车仪表盘的指针位置实施检测。首先,介绍了基于机器视觉对汽车仪表的符号片及指针进行自动检测的系统组成。接着,针对经典Hough变换发散映射运算量大的缺点,提出了基于收敛映射CM-Hough变换进行指针检测的算法,给出了利用Hough变换的检测结果直接解算指针位置的方法。最后,将算法由软件编程实现,通过测试实验验证了算法的实时性和有效性,测试数据分析显示了指针位置误差小于1%。 相似文献