Laser irradiation cell photothermal therapy assisted by gold nanoparticles

The strong absorption of gold nanoparticles in the visible spectral range allows the localized generation of heat in a volume of only a few tens of nanometer. The efficient conversion of strongly absorbed light by plasmonic gold nanoparticles to heat energy and their easy bioconjugation suggest that the gold nanoparticles can be used as selective photothermal agents in molecular cell targeting. The selective destruction of alkaline phosphatase, the permeabilization of the cell membrane and the selective killing of cells by laser irradiating gold nanoparticles were demonstrated. The potential of using this selective technique in molecularly targeted photothermal therapy and transfection is discussed.

A new method for spectrum reproduction and interferogram processing

On the basis of researchon the theory and mathe matics of interference data collection of the spatially modulated polarization interference imaging spectrometer designed by us, this paper mainly analyses and compares three different methods of spectrum reconstruction and interferogram processing. Specially, the authors introduce the nonparametric model of Music algorithm which is maturely used in power spectrum estimation into the spectrum reconstruction processing for the first time. This method prodigiously improves the resolution of reproduced spectrum, and provides a better math matic model for the improvement of resolving power in spectrum reproduction.

Transfer property of electron pulse in a femto-second electron diffraction system

An ultra-fast electron diffraction system has been designed. The static and dynamic characters of an electron pulse with 150 fs temporal dispersion are studied during its transmission in the whole ultra-fast electron diffraction system, including the size of the electron spot, temporal dispersion, distribution of azimuths and elevation angles. The initial status of the photoelectrons are put down by Monte Carlo method, both the two dimensional and three dimensional electric fields are calculated by finite difference method and the magnetic flux are. calculated by finite element method.

聚酰亚胺的结构改性及其杂化材料的合成

本论文综述了聚酰亚胺结构改性与杂化的研究现状与发展趋势。合成了2,2',3,3'-联苯四酸二酐（2,2',3,3'-BPDA），其单晶结构分析表明该单体具有非线性和非共平面结构，不同于其异构体3,3',4,4'-BPPA；对两个异构体的模型化合物和聚合物进行了分子模拟，表明二者沿联苯轴的旋转位垒相差10~9倍；以2,2',3,3'-BPDA为单体与不同二胺反应制得一系列新型的聚酰亚胺均聚物和共聚物，它们显示出高Tg、高耐热性和低结晶性；联苯型聚酰亚胺的溶解性因引入柔性单元、非共平面结构和采用共缩聚而得到改善，其中使用2,2',3,3'-联苯四酸二酐还可提高热稳定性。在含大量水的溶剂中制得高分子量和具有良好力学性能的聚酰亚胺，这与热酰亚胺化时的链增长过程有关。通过溶胶-凝胶、掺杂和分散等方法成功地制得聚酰亚胺－TiO_2（BaO/TiO_2, BaTiO_3）等纳米杂化材料，这些材料具有良好的耐热性、透明性和力学性能，其介电性能、导电性能和压电性能也得到明显的提高。

Abnormal photoabsorption in high resistance GaN epilayer

Unintentionally doped GaN epilayers are grown by the metalorganic chemical vapor deposition (MOCVD). Photovoltaic (PV) spectroscopy shows that there appears an abnormal photoabsorption in some undoped GaN films with high resistance. The peak energy of the absorption spectrum is smaller than the intrinsic energy band gap of GaN. This phenomenon may be related to exciton absorption. Then metal-semiconductor-metal (MSM) Schottky photodetectors are fabricated on these high resistance epilayers. The photo spectrum responses are different when the light individually irradiates each of the two electrodes with the photodetector which are differently biased. When the excitation light irradiates around the reverse biased Schottky junction, the responsivity is almost one order of magnitude larger than that around the forward biased junction. Furthermore, when the excitation light irradiates the reverse biased Schottky junction, the peak energy of the spectrum has a prominent red-shift compared with the peak energy of the spectrum measured with the excitation light irradiating the forward biased Schottky junction. The shift value is about 28 meV, and it is found to be insensitive to temperature. According to the analyses of the distribution of the electric field within the MSM device and the different dependences of the response on the electric field intensity between the free carriers and excitons, a reliable explanation for the different response among various areas is proposed.

The exciton-longitudinal-optical-phonon coupling in InGaN/GaN single quantum wells with various cap layer thicknesses

This paper studies the exciton-longitudinal-optical-phonon coupling in InGaN/GaN single quantum wells with various cap layer thicknesses by low temperature photoluminescence (PL) measurements With increasing cap layer thickness, the PL peak energy shifts to lower energy and the coupling strength between the exciton and longitudinal-optical (LO) phonon, described by Huang-Rhys factor, increases remarkably due to an enhancement of the internal electric field With increasing excitation intensity, the zero-phonon peak shows a blueshift and the Huang-Rhys factor decreases These results reveal that there is a large built-in electric field in the well layer and the exciton-LO phonon coupling is strongly affected by the thickness of the cap layer

Energy level analyses of even-parity J=1 and 2 Rydberg states of Sn I by multichannel quantum defect theory

This paper analyzes the energy levels along the even-parity J=1 and 2 Rydberg series of Sn I by multichannel quantum defect theory. A good agreement between theoretical and experimental energy levels was achieved. Below 59198 cm~(-1), a total of 85 and 23 new energy levels, respectively, in the J=1 and J=2 series, which cannot be measured previously by experiments, are predicted in this work. Based on the calculated admixture coefficients of each channel, interchannel interactions were discussed in detail. The results are helpful to understand the characteristics of configuration interaction among even-parity levels in Sn I.