单分子监测与操纵(Single-Molecule Observation and Manipulation)综合利用光学工具、荧光标记和扫描探针显微技术对单分子进行成像和监测。过去在观测大分子行为时,必须设法使样本中反应同步进行,以获取相对准确的分布信息。而单分子...单分子监测与操纵(Single-Molecule Observation and Manipulation)综合利用光学工具、荧光标记和扫描探针显微技术对单分子进行成像和监测。过去在观测大分子行为时,必须设法使样本中反应同步进行,以获取相对准确的分布信息。而单分子监测与操纵技术的出现,使得研究生理环境下的实时反应中大分子的构型、分布和反应进程成为可能,并为进一步解释DNA转录、RNA聚合、动力蛋白和蛋白质折叠机理等一系列过程提供了有力的研究手段。使用扫描隧道显微镜(Scanning Tunneling Microscope,STM),可以更为深刻地观察分子的量子电动力学行为,理解分子水平上力学作用、电磁作用及化学作用的相互影响,并以此为基础设计极其高效的纳米器件。对上述三个领域(光学工具、荧光标记、扫描探针显微技术)做了简要介绍,并重点阐述其在生物大分子研究中的具体应用。展开更多
The electromagnetic interaction of light with polar materials shows a sharp and well defined electromagnetic response in the infrared(IR)region that consists mainly of excitation of optical phonons.Similar to surface ...The electromagnetic interaction of light with polar materials shows a sharp and well defined electromagnetic response in the infrared(IR)region that consists mainly of excitation of optical phonons.Similar to surface plasmons in the visible region,surface phonons can couple efficiently to infrared light in micron-sized antennas made of polar materials.We applied the boundary element method to calculating the infrared electromagnetic response of single SiC disks acting as effective infrared antennas as a function of different parameters such as disk size and thickness.We also analyzed the effect of locating a probing metallic tip near the SiC disk to scatter light in the proximity of the SiC disk,thereby obtaining new spectral peaks connected with localized modes between the tip and the SiC disk.We then further investigated their application in IR scanning probe microscopy.A near-field map of the phononic resonances enhances the understanding of the nature of the IR extinction peaks.展开更多
Scanning near-field acoustic microscope （SNAM） combines the ultrasonic detection technology with scanning near-field microscopy. The main characteristic of such microscope is that the acoustic wave is produced or de...Scanning near-field acoustic microscope （SNAM） combines the ultrasonic detection technology with scanning near-field microscopy. The main characteristic of such microscope is that the acoustic wave is produced or detected in near-field area whether ultrasonic transducer acts as generator or detector. The resolution of SNAM can reach to nanometer scale. First, two typical SNAMs, scanning electron acoustic Inicroscope and scanning probe acoustic microscope, will be introduced in this paper. The working principle of our homemade SNAM based on a commercial scanning probe microscope will be reported, together with some recent results from this homemade SNAM.展开更多
文摘The electromagnetic interaction of light with polar materials shows a sharp and well defined electromagnetic response in the infrared(IR)region that consists mainly of excitation of optical phonons.Similar to surface plasmons in the visible region,surface phonons can couple efficiently to infrared light in micron-sized antennas made of polar materials.We applied the boundary element method to calculating the infrared electromagnetic response of single SiC disks acting as effective infrared antennas as a function of different parameters such as disk size and thickness.We also analyzed the effect of locating a probing metallic tip near the SiC disk to scatter light in the proximity of the SiC disk,thereby obtaining new spectral peaks connected with localized modes between the tip and the SiC disk.We then further investigated their application in IR scanning probe microscopy.A near-field map of the phononic resonances enhances the understanding of the nature of the IR extinction peaks.
基金supported by the National Natural Science Foundation of China (Grant Nos.50971011 and 10874006)Beijing Natural Science Foundation (Grant No.1102025)Research Fund for the Doctoral Program of Higher Education of China (Grant No.20091102110038)
文摘Scanning near-field acoustic microscope （SNAM） combines the ultrasonic detection technology with scanning near-field microscopy. The main characteristic of such microscope is that the acoustic wave is produced or detected in near-field area whether ultrasonic transducer acts as generator or detector. The resolution of SNAM can reach to nanometer scale. First, two typical SNAMs, scanning electron acoustic Inicroscope and scanning probe acoustic microscope, will be introduced in this paper. The working principle of our homemade SNAM based on a commercial scanning probe microscope will be reported, together with some recent results from this homemade SNAM.
