GZO厚度对非晶硅电池中复合背电极的影响

在非晶硅太阳能电池中加入复合背电极是提高非晶硅太阳能电池光电转换效率和稳定性的有效手段.本文利用磁控溅射技术在非晶硅薄膜太阳能电池上制备了ZnO :Ga(GZO)/Al复合背电极,研究了GZO厚度对GZO薄膜光电性质及非晶硅电池中GZO/Al复合背电极性能的影响.研究表明：随着GZO层厚度的增加,GZO薄膜的光电性质均表现出较高水平,适合制备GZO/Al复合背电极;相较于单层Al背电极的非晶硅太阳能电池,具有GZO/Al复合背电极的太阳能电池性能大幅提高.当GZO层厚度为100 nm时,太阳能电池的短路电流(I_SC)、开路电压(V_OC)和填充因子(FF)分别达到8.66 mA,1.62 V和54.7%.     

On energy conservation for finite element approximation of flow-induced airfoil vibrations

In this paper the numerical approximation of a two-dimensional fluid–structure interaction problem is addressed. The fully coupled formulation of incompressible viscous fluid flow interacting with a flexibly supported airfoil is considered. The flow is described by the incompressible system of Navier–Stokes equations, where large values of the Reynolds number are considered. The Navier–Stokes equations are spatially discretized by the finite element method and stabilized with a modification of the Galerkin Least Squares (GLS) method; cf. [T. Gelhard, G. Lube, M.A. Olshanskii, J.-H. Starcke, Stabilized finite element schemes with LBB-stable elements for incompressible flows, Journal of Computational and Applied Mathematics 177 (2005) 243–267]. The motion of the computational domain is treated with the aid of Arbitrary Lagrangian Eulerian (ALE) method and the stabilizing terms are modified in a consistent way with the ALE formulation.     

Relating time complexity of protein folding simulation to approximations of folding time

Finkelstein and Badretdinov [A.V. Finkelstein, A.Y. Badretdinov, Rate of protein folding near the point of thermodynamic equilibrium between the coil and the most stable chain fold, Fold. Des. 2 (1997) 115-121] approximated the folding time of protein sequences of length n by exp(λ⋅n2/3±χ⋅n1/2/2)ns, where λ and χ are constants close to unity. Recently, Fu and Wang [B. Fu, W. Wang, A ²O(n1−1/d⋅logn) time algorithm for d-dimensional protein folding in the HP-model, in: J. Daz, J. Karhumäki, A. Lepistö, D. Sannella (Eds.), Proceedings of the 31st International Colloquium on Automata, Languages and Programming, in: Lecture Notes in Comput. Sci., vol. 3142, Springer-Verlag, Heidelberg, 2004, pp. 630-644] published an exp(O(n1−1/d)⋅lnn) algorithm for d-dimensional protein folding simulation in the HP-model, which is close to the folding time approximation by Finkelstein and Badretdinov and can be seen as a justification of the HP-model for investigating general complexity issues of protein folding. We propose a stochastic local search procedure that is based on logarithmic simulated annealing. We obtain that after (m/δ)^a⋅D Markov chain transitions the probability to be in a minimum energy conformation is at least 1−δ, where m?b(d)⋅n is the maximum neighbourhood size (b(d) small integer), a is a small constant, and D is the maximum value of the minimum escape height from local minima of the underlying energy landscape. We note that the time bound is instance-specific, and we conjecture D<n1−1/d as a worst case upper bound. We analyse experimentally on selected benchmark problems for the d=2 case.     

Preparation of acidic or bifunctional catalysts by means of straightforward calcination of as-synthesized [Ga]-ZSM-5 zeolites obtained from alkali-free media. Propane aromatization

Propane aromatization (530°C, 1 atm) was used as a reaction model to evaluate the effect of the calcination temperature on the catalytic properties of an as-synthesized [Ga_1.3]-ZSM-5 zeolite obtained from alkali-free media and calcined at two different temperatures: 530°C (C-530) and 750°C (C-750). Results show that in spite of its lower acidity, C-750 is more active and selective toward aromatics than C-530. This is probably due to the fact that at higher temperature the decomposition of organic compounds used during the zeolite synthesis is accompanied by a partial degalliation of the zeolitic support leading to the production of a bifunctional xGa₂O₃ /H-[Ga_y-ZSM-5(2x+y=1.3)catalyst.     

New oxide phosphors for FEDs: Ruddlesden—Popper phases synthesized with IIIB‐group elements

Abstract— A red‐emitting phosphor, SrTiO³:Pr³⁺, for low‐voltage‐type FEDs and VFDs was developed by Futaba Corporation in 1996. The addition of Al or Ga is essential in the preparation of this phosphor because it improves the luminescence efficiency dramatically. For this impurity effect, Futaba Corporation proposed a charge‐compensation mechanism, which was supported by a recent observation of emission lines due to Al³⁺‐Pr³⁺ pairs. In addition, it was found that Al also works as a scavenger of planar defects, presumably SrO thin layers interleaved in the SrTiO³ lattice, by forming strontium aluminates. The latter mechanism suggests the possibility that a similar impurity effect can be found in materials with crystal structures, including alkaline‐earth oxide layers (Ruddlesden‐Popper phases).     

Ga3O2-和Ga4O3-的结构及稳定性的研究

采用密度泛函理论（DFT）中的B3LYP方法和BP86方法,O原子基于6-311+G（d,p）基组,Ga原子基于Stuttgart基组,对Ga₃O₂^-/0与Ga₄O₃^-/0团簇的各种可能构型进行了几何优化,预测了各团簇的最稳定结构,并研究了Ga₃O₂^-和Ga₄O₃^-最稳定结构的成键特性、振动特性和稳定性。对比B3LYP和BP86计算结果发现得到的异构体的结构和能量顺序相同,且阴离子的基态构型与中性分子的构型相接近,都是平面C_2v型,都存在由2个Ga原子和一个O原子形成的三中心二电子（3c-2e）桥键。两结构中处于端位的"Ga-O"键的Wiberg键级数值较大,分别为0.50、0.55;振动频率分别为713.92、832.76cm-1,在红外谱图上皆对应一明显的强振动峰,表明该"Ga-O"结构单元成键稳定,是决定团簇结构稳定的重要因素。计算得到是Ga₃O₂^-和Ga₄O₃^-基态结构的LUMO与HOMO的能量之差（分别为2.75、2.84eV）,以及电子绝热剥离能（ADE）和电子垂直剥离能（VDE）,都表明两基态结构具有较好的热力学稳定性。     

电化学方法脱除高岭土中铁、钛杂质的研究

除去高岭土中铁、钛等杂质，有利于它的广泛应用．对淮北地区高岭土进行电化学处理，并对处理前后的试样进行了SiO2，Al2O3，Fe2O3和TiO2含量的测定，发现在保持SiO2和Al2O3总量基本不变的前提下，Fe2O3，TiO2的脱除率分别达到60．0％和31．7％．同时配合透射电子显微镜、X-衍射和EDX能谱对样品进行分析．结果表明，电化学处理后的高岭土颗粒明显细化，铁、钛含量明显减少．     

金属间化合物Sm_3(Fe_(1-x)V_x)_(29)的结构及其微观机制研究

利用X射线衍射,金相显微镜,能谱分析以及差示扫描量热(DSC)等手段对金属间化合物Sm3(Fe1-xVx)29(x=0.01,0.03,0.05,0.08,0.1)的结构及其微观机制进行了研究.结果表明,金属间化合物Sm3(Fe1-xVx)29(x=0.01,0.03,0.05,0.08,0.1)的结构均为3:29型结构,并且随V含量增加,金属间化合物Sm3(Fe1-xVx)29的晶格常数和晶胞体积V均呈减少趋势.当x>0.05时,金属间化合物Sm3(Fe1-xVx)29中的杂质相明显呈现出来.随着V含量的增加,居里温度(TC)呈单调上升趋势.     

Fabrication of GaN films through reactive reconstruction of magnetron sputtered ZnO/Ga_2O_3

1　INTRODUCTIONGallium nitride (GaN) is one of the most po tential semiconductors. GaN has a direct energyband gap of 3.4 eV at room temperature and highexternal photoluminescence quantum efficiency, aswell as a high excitonic binding energy of20 meV[1]. It is an ideal material for fabrication ofultraviolet(UV)/blue/green light emitting diodes(LEDs), laser diodes(LDs), UV detectors and de vices operating in high temperature, high frequen cy and high power co…     

铜线杆质量影响因素浅谈

从杂质元素、稀土元素、等方面讨论了铜线杆质量影响因素,以及表面质量对铜材加工的影响。