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991.
992.
随着能源危机的加剧,太阳能电池作为开发和利用太阳能的一种普遍形式, 日益受到世界各国的重视.随着太阳能电池向着高效率、薄膜化、无毒性和原材料丰富的方向发展, 单纯的硅系太阳能电池已经无法达到这样的要求,因此新的材料和工艺的开发利用迫在眉睫. 本文研究了碳材料在硅异质节上实现光伏效应的改善及其可能在太阳能电池上的应用. 采用脉冲激光沉积方法制备的Co2-C98/Al2O3/Si异质结构在标准日光照射 (AM1.5, 100 mW/cm2)条件下,可获得0.447 V的开路电压和18.75 mA/cm2的电流密度, 转换效率可达3.27%.通过电容电压特性和暗条件下的电输运性能测量, 证明了氧化铝层的引入不但对单晶硅的表面起到了物理钝化作用,减小了反向漏电流, 使异质结界面缺陷、界面能级和复合中心减少,还起到了场效应钝化作用, 增加了异质结界面的势垒高度,增加了开路电压,使异质结的光伏效应显著增强. 相似文献
993.
994.
X. B. Wan Q. P. Wang Z. J. Liu X. Y. Zhang Z. H. Cong S. Z. Fan G. F. Jin 《Laser Physics》2012,22(1):106-110
Raman lasers based on c-Nd:YVO4 crystals can generate 1178 nm Stokes line, which can be frequency-doubled to realize 589 nm sodium lasers. We make comparative
experimental studies of c-Nd:YVO4/YVO4 Raman lasers and c-Nd:YVO4 self-Raman lasers. About these two kinds of lasers, the output characteristics of power, center wavelength and beam quality
are measured and compared. 相似文献
995.
P Dolashka F Zal A Dolashki L Molin P Traldi B Salvato 《Journal of mass spectrometry : JMS》2012,47(7):940-947
The understanding of the function of macromolecular complexes is mainly related to a precise knowledge of their structure. Recently, the development of suitable mass spectrometric techniques (electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI)) and multi-angle laser light scattering has enabled mass determination of native complexes and of their subunits. By these techniques, the structure and association/dissociation behavior of huge molecules of molluscan Octopus vulgaris, Sepia officinalis and Rapana venosa have been characterized. Molecular masses of the native and dissociated molecule of cephalopodan Hcs O. vulgaris (3545 and 359.3?kDa, respectively) and S. officinalis (4134 and 443.8?kDa, respectively) revealed that only one type subunit organizes their molecules, while the presence of two isoforms with different masses (422.8 and 400.0?kDa) has been determined for gastropodan R. venosa Hc, aggregated into didecamers. The difference of their structural subunits was also established after limited proteolysis with TPCK-trypsin. Eight functional units (FUs) with masses of?~?50?kDa were isolated from both subunits of RvH and isoform of Sepia officinalis, while seven FUs were purified from OvH. Further characterization of proteins by ESI-mass spectrometry (MS) and MALDI-MS, methods gave insights into post-translational modifications such as glycosylation. Glycosylation of O. vulgaris and S. officinalis Hcs was suggested based on the differences (11.6 and 40.0?kDa, respectively) between the masses measured by ESI-MS and those calculated by their gene sequences. 相似文献
996.
Phase transition,dielectric and piezoelectric properties of NaNbO3–Bi0.5Li0.5TiO3 lead-free ceramics
Lingling Fu Dunmin Lin Qiaoji Zheng Xiaochun Wu Lang Wu Hailing Sun Yang Wan Ximing Fan Chenggang Xu 《Current Applied Physics》2012,12(6):1523-1528
Lead-free ceramics (1?x)NaNbO3–xBi0.5Li0.5TiO3 have been fabricated by an ordinary sintering technique, and their electric properties and temperature characteristics have been studied. All the ceramics possess a perovskite structure with orthorhombic symmetry, indicating that (Bi0.5Li0.5)TiO3 diffuses into NaNbO3 lattices to form a new solid solution. A low (Bi0.5Li0.5)TiO3 doping level transforms the NaNbO3 ceramics from antiferroelectric to ferroelectric. The ceramics with x ≤ 0.075 are normal ferroelectric, and the ferroelectric-paraelectric phase become diffusives with the doping level of Bi0.5Li0.5TiO3 increasing. As x increases, the Curie temperature of the ceramics decreases linearly, while the relative permittivity εr increases. 0.925NaNbO3–0.075(Bi0.5Li0.5)TiO3 ceramic exhibits the relatively large piezoelectric constant (d33 = 58 pC/N), high Curie temperature (TC = 228 °C) and good temperature stability, suggesting that the ceramics are one of new possible candidates for lead-free piezoelectric materials. 相似文献
997.
Lihua Zhang Zhenyan Tang Shaolin Wang Ding Ding Mingshu Chen Huilin Wan 《Surface science》2012,606(19-20):1507-1511
The growth, structures, and vibrational properties of ultrathin manganese oxide films on Rh(111) had been investigated using high-resolution electron energy loss spectroscopy (HREELS), X-ray photoelectron spectroscopy (XPS), low energy electron diffraction (LEED), low energy ion scattering spectroscopy (LEIS) and Auger electron spectroscopy (AES). MnOx grew in a layer-by-layer fashion on the Rh(111) surface. HREELS phonon features and XPS binding energies showed that an OMnO like tri-layer formed initially. Which was stable on the Rh(111) surface with MnOx coverage less than one monolayer. At above one monolayer, Mn3O4 was preferred as indicated from a four-phonon feature peaked at 13.3, 39, 68 and 83 meV in HREELS. Higher temperature oxidation and annealing were found to improve the long-range order of the MnOx films. 相似文献
998.
We demonstrate a tunable crystalline Raman laser by varying the temperature of Raman crystal. Nd:YAG and YVO(4) crystals were selected as the laser and Raman gain media, respectively. The center wavelength of this Nd:YAG/YVO(4) Raman laser was tuned over a 0.49 nm range from 1175.76 to 1175.27 nm when the temperature of the Raman crystal was adjusted from 5 °C to 150 °C. The characteristics of this Raman laser including tunability, output power, and beam quality factors (M(2)) dependent on temperature were also studied in this paper. 相似文献
999.
1000.
研究设计了一个有效的可扩展的二维刻槽离子芯片。为了减少激光在离子芯片表面的散射,使被囚禁离子更加稳定,并使激光容易控制和探测成行的被囚禁离子,在每两个平行的射频电极中间刻槽使冷却光和探测光路径可穿过芯片。把控制离子运动的直流电极跟射频电极分开,减轻了不同电压对被囚禁离子的干扰,改进了对离子的控制。用有限元分析的方法对芯片表面上方的电势分布做了计算模拟。模拟结果表明,在这种新型的刻槽可扩展芯片上可以生成一个可扩展的离子阱阵列。这种结构提供了一个新颖的刻槽二维平面离子芯片,被囚禁其上的线形离子阵列可用来进行大型的量子信息处理。 相似文献