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991.
Shun‐Li OuYang Cheng‐Lin Sun Mi Zhou Zhan‐Long Li Zhi‐Wei Men Dong‐Fei Li Zuo‐Wei Li Shu‐Qin Gao Guo‐Hui Lu 《Journal of Raman spectroscopy : JRS》2010,41(12):1650-1654
Using the technique of liquid‐core optical fiber (LCOF), we measured the Raman scattering cross sections (RSCSs) of the carbon–carbon (C C) stretching vibrational modes of all‐trans‐β‐carotene in carbon disulfide (CS2) at concentrations ranging from 10−6 to 10−11 M . It was found that the RSCSs of all‐trans‐β‐carotene were extremely high with decreasing concentration, and the absolute RSCS of C stretching modes of all‐trans‐β‐carotene reached the value of 2.6 × 10−20 cm2 molecule−1 Sr−1 at 8 × 10−11 M , which is larger than at 8 × 10−6 Mby 4 orders of magnitude. A theoretical interpretation of the anomalous experimental results is given, which introduces a qualitative nonlinear model of coherent weakly damped electron‐lattice vibrations in structural order of all‐trans‐β‐carotene. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
992.
J.-F. Yang B.-T. Zhang J.-L. He H.-T. Huang X.-L. Dong J.-L. Xu C.-H. Zuo S. Zhao X.-Q. Yang G. Qiu Z.-K. Liu 《Applied physics. B, Lasers and optics》2010,98(1):49-54
With a non-critically phase-matched high gray-trace resistance KTP (GTR-KTP) crystal, a high-power intracavity optical parametric oscillator (IOPO) emitting at the wavelength of 1.5 μm and pumped by a diode-side-pumped acousto-optically Q-switched Nd:YAG laser is experimentally demonstrated. At the frequency repetition rate of 6 kHz, the maximum average power of 6.36 W at signal wavelength 1570 nm with a pulse width of 9.94 ns is obtained from IOPO based on GTR-KTP, corresponding to a peak power of 107 kW and a single-pulse energy of 1.06 mJ, respectively. We have compared the GTR-KTP IOPO with common KTP IOPO using the same scheme. At the same cavity design, frequency repetition rate and pump condition, only 5.42 W average output power with pulse width 13.82 ns is obtained from IOPO based on common KTP. Besides the higher output power, the output stability of GTR-KTP IOPO is much better than that of common KTP OPO. The output instability of GTR-KTP IOPO is 0.83% versus 6.7% of the common KTP IOPO. 相似文献
993.
994.
研究了铬过渡层对纳米球刻蚀法制备二维银纳米点阵结构的影响。首先利用自组装的方法在玻璃基底上制备出单层排列的聚苯乙烯纳米球阵列,然后使用物理气相沉积的方法在二维聚苯乙烯纳米球阵列上沉积一层铬层作过渡层和银层,最后将玻璃基底在乙醇溶液中超声移除聚苯乙烯纳米球,得到二维的银纳米点阵。实验发现,随着铬过渡层厚度的增加,制得的二维银纳米点阵阵列趋于完整,单个的银纳米颗粒由椭圆状转变为三角形形状。实验中测量了所得到的二维银纳米结构的吸收光谱。 相似文献
995.
Probe 1 was designed and synthesized as a new fluorescent molecular probe for thiols in PBS buffer at physiological condition. This
fluorescent molecular probe consists of a thiol reaction moiety bound to a coumarin fluorophore. Its fluorescence quantum
yield is low, but a drastic enhancement of fluorescence intensity was observed in the presence of thiols. Possible interference
with other analytes was examined. Probe 1 displays a highly selective fluorescent enhancement with thiols, and the probe was successfully applied to thiols determination
in intracellular, in human urine and blood samples. 相似文献
996.
Qianqian Cao Chuncheng Zuo Lujuan Li Nan Zhang 《Macromolecular theory and simulations》2010,19(6):298-308
The conformational transition of a single bottle‐brush polyelectrolyte with charged and neutral side chains is studied through MD simulations. Counterions are included explicitly and no additional salt is added. The structure of the polyelectrolyte and the counterion condensation are found to depend greatly on the Bjerrum length. As the Bjerrum length increases, the neutral side chains in a poor solvent can condense into clusters with variable size. Moreover, the polyelectrolyte forms globular structures at large or very small Bjerrum lengths. This transition is quite different from that in the case of a good solvent, in which there are not observable clusters and a globular structure is only formed at large Bjerrum lengths.
997.
Haoyi Zuo Qiaojun Liu Jieyu Wang Ling Yang Shirong Luo 《Journal of Quantitative Spectroscopy & Radiative Transfer》2010,111(1):2106-795
A wavelength-selecting method to improve the precision of retrieving the aerosol size-distribution is presented. The optimal wavelength set selected by using this method can decrease the degree of ill-condition of the Mie matrix effectively, indicating that the optical depth set of the optimal wavelength set is more unjammable than the optical depth sets of other wavelength sets. By using the computer simulation and the actual measurements of the size-distribution of Al2O3 particles in water, the wavelength-selecting method is proved to be validity to some extent. 相似文献
998.
Energetic electrons associated with magnetic reconnection in the magnetic cloud boundary layer 总被引:2,自引:0,他引:2
Here is reported in situ observation of energetic electrons (~100-500 keV) associated with magnetic reconnection in the solar wind by the ACE and Wind spacecraft. The properties of this magnetic cloud driving reconnection and the associated energetic electron acceleration problem are discussed. Further analyses indicate that the electric field acceleration and Fermi-type mechanism are two fundamental elements in the electron acceleration processes and the trapping effect of the specific magnetic field configuration maintains the acceleration status that increases the totally gained energy. 相似文献
999.
Pure ZnO and Ni-doped ZnO rods have been prepared by hydrothermal method at a temperature of 120 °C. The morphological, structural, magnetic and optical properties of the as-prepared rods were investigated by means of field emission scanning electron microscopy, X-ray diffraction, vibrating sample magnetometer and photoluminescence. All the samples are radial-grown hexagon rods with diameter from 470 to 720 nm and length of 4-6 μm. X-ray diffraction shows that the rods have single crystalline wurtzite structure without other impurity phases. The pure ZnO rods and Ni-doped ZnO rods have ferromagnetism at room temperature, and the special saturation magnetization deduces with the increasing diameter of rods. These results reveal that the saturation magnetization of the ZnO rods depends on the surface-to-volume ratio of rods rather than the Ni doping concentrations. The photoluminescence spectra studies show the same diameter dependences of oxygen vacancies as that of magnetization, which demonstrates that oxygen vacancies at surface of rods play an important role in introducing ferromagnetism. The annealing in rich oxygen and reducing atmospheres confirms this argument further. 相似文献
1000.
Yalu Zuo Zhenhua Yu Shiming Yan Xueyun Zhou Li Zhang 《Applied Surface Science》2010,256(20):6013-6017
The electrical and ferromagnetic properties of (In0.9−xTbxSn0.1)2O3 and (In0.99−yTb0.01Sny)2O3 films fabricated by sol-gel method have been investigated. All the films show room temperature ferromagnetism. The magnetic moment per Tb ion of (In0.9−xTbxSn0.1)2O3 films first increases and then decreases with the increasing Tb content. The variation of conductivity with Tb content is coincident with that of the magnetic moment. Furthermore, the conductivity and magnetic moment variations with Sn content y in (In0.99−yTb0.01Sny)2O3 films also have the similar trend. These results imply that the ferromagnetism may originate from the carrier-mediated mechanism. 相似文献