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201.
Yuguo Li Ruiqin Peng Xianwu Xiu Xuelei Zheng Xiaosen Zhang Guannan Zhai 《Superlattices and Microstructures》2011,50(5):511-516
Tin oxide (SnO2) nanoparticles were fabricated by evaporation of Sn powers at 1000 °C in air pressure. The as-deposited SnO2 particles were single crystal structure, which were mostly spherical shape, the diameter of particles was ranging from 200 to 600 nm. The photoluminescence (PL) spectrum showed that a sharp emission peak at around 393 nm with the excitation wavelength at 325 nm, which suggested possible applications in nanoscaled optoelectronic devices. It was also found that the holding time affects the morphology of the products. The formation mechanism of SnO2 particles was discussed. 相似文献
202.
T. Zhai S. Chen Y. Zhou J. Shi X. Zhang D. Liu 《Applied physics. B, Lasers and optics》2011,104(4):935-939
Flexible and adjustable beam splitters, expanders/compressors and the cloak are presented based on a universal two-dimensional
transformation formula for the embedded transformation optics. Nonlinear transformation results by the suggested formula under
different conditions reveal several interesting phenomena and potential applications. All beam controllers are achieved by
the nonlinear coordinate transformation. 相似文献
203.
Wang Changzhou Zhai Jiwei Song Zhitang Shang Fei Yao Xi 《Applied Physics A: Materials Science & Processing》2011,103(1):193-198
Phase-change behavior in Si/Sb80Te20 nanocomposite multilayer films were investigated by utilizing in situ resistance measurements. It was found that the crystallization
temperature increased firstly with increasing Si layer thickness within the multilayer films, and then remained almost unchanged
at 170°C. The multilayer films have the merits of both good thermal stability and fast phase-change speed. An increase in
crystallization temperature by around 95°C was observed for the multilayer films when the Sb80Te20 layer thickness was reduced to 3 nm. Cross-sectional transmission electron microscopy (TEM) observations revealed that Si/Sb80Te20 nanocomposite multilayer films had layered structures with clear interfaces. The reversible phase change between set and
reset states was verified in phase-change random access memory (PCRAM) cell based on [Si (1 nm)/Sb80Te20 (5 nm)]17 multilayer film. 相似文献
204.
Neutrals ejection in intense femtosecond laser ablation 总被引:1,自引:0,他引:1
Time-resolved shadowgraphs and holograms of intense femtosecond laser ablation of aluminum are reported. The different bending trends of interference fringes are found in the ablations of aluminum and other materials at probe wavelengths of 400 and 800 nm, for the first time to our knowledge, which could be attributed to the ejection of massive neutral droplets induced by critical-point phase separation during the second material ejection. 相似文献
205.
We present an all-fiber bidirectional passively mode-locked soliton laser with what we believe is a novel cavity configuration. Using a four-port circulator, we incorporate two different semiconductor saturable absorber mirrors (SESAMs) into the laser cavity, which enables bidirectional mode locking. The laser allows the generation of two independent countercirculating mode-locked pulse trains, each with an individual fundamental repetition rate that can be adjusted by varying the SESAM pigtail length. Two countercirculating pulse trains with repetition rates of 21.3 and 15.2 MHz are obtained simultaneously. By controlling the intracavity loss imposed on these two pulse trains, either one of the two pulse trains can be switched on or off. The bidirectional operation with other repetition rates is also demonstrated. 相似文献
206.
L.H. Kong R.R. ChenT.T. Song Y.L. Gao Q.J. Zhai 《Journal of magnetism and magnetic materials》2011,323(24):3285-3289
The magnetic properties and the annealing process of Fe78Zr7B15 amorphous ribbons are investigated by X-ray diffraction (XRD), differential scanning calorimetry, and vibrating sample magnetometer. The fully amorphous structure of the as-quenched ribbons is confirmed by the XRD pattern. The Curie temperature and the saturation magnetization Ms of the ribbons are 305 °C and 124.3 emu/g, respectively. Annealing at 550 °C can result in an increase in Ms with annealing time due to the increasing crystallized volume fraction of α-Fe phase. The optimized annealing process is established at 550 °C for 20-30 min with maximum Ms of 146.6 emu/g. The morphology of the ribbons annealed at 550 °C is observed by scanning electron microscopy, showing that nanocrystalline α-Fe grains are dispersed in an amorphous matrix. 相似文献
207.
Guomin JiYaxin Zhai Changfeng FangYuqing Xu Bin CuiDesheng Liu 《Physics letters. A》2011,375(14):1602-1607
By applying non-equilibrium Green?s functions in combination with the density-functional theory, we investigate the transport behavior of molecular devices composed by metal electrode-C60 molecule-metal electrode. Our results show that the electronic transport properties are affected obviously by the different contact distances between the electrodes, and the tunneling current decreases approximately exponentially at a certain bias with the increasing of contact distances. The negative differential resistance is observed and the peak-to-valley ratio can be tuned by different contact distances. The mechanisms of the contact distance effect and the negative differential resistance behavior are proposed. 相似文献
208.
A method for fast sensitive ultraviolet detection of amino acids was developed with a disposable electrophoresis microdevice. The microdevice was conveniently constructed by fixing a fused-silica capillary with a sampling fracture to a printed circuit board. During the separation process, the on-column conjugation of amino acids with cupric cation led to the ultraviolet absorption at 232 nm that could be directly used for fast analysis of amino acids. Using 20 mM boric acid (pH 5.3) containing 5 mM cupric cation and 0.015% Tween 20 as running buffer, this method could completely separate lysine, glutamine and serine at a sampling time of 2 s at +210 V and a separation voltage of +1800 V (240 V/cm). The theoretical plate numbers were from 140,000 to 205,000 plates/m. The linear ranges were from 10 to 500 μM for lysine, 20-1000 μM for glutamine and serine. The novel protocol had been successfully used to detect amino acids in beverage samples with recovery more than 85.0%, indicating its advantages and potential analytical application in different fields. 相似文献
209.
三层介质长圆柱界面上极化电荷和磁化电流的分立镜像 总被引:1,自引:0,他引:1
计算表明,三层介质无工圆柱界面上的极化电荷和磁化电流可用多个分立镜像代替,从而使电场和磁场的计算更简单和直观。 相似文献
210.
Composite CoFe2O4-BaTiO3 films were prepared by combining method of sol-gel and electrophoretic deposition. CoFe2O4 thick films were prepared by electrophoretic deposition method and then BaTiO3 precursor solution was spin-coated on these thick films to obtain dense structure. X-ray diffraction indicated that the films consisted of both spinel CoFe2O4 and perovskite BaTiO3 phase. Dielectric properties and leakage current conduction of the films were studied. Leakage current characterization of the films exhibits an Ohmic conduction behavior at lower electric field and space charge limited conduction behavior at higher electric field, respectively. 相似文献