平台式FPGA中可重构存储器模块的设计

可重构静态存储器(SRAM)模块是场可编程门阵列(FPGA)的重要组成部分,它必须尽量满足用户不同的需要,所以要有良好的可重构性能.本文设计了一款深亚微米工艺下的16-kb的高速,低功耗双端口可重构SRAM.它可以重构成16Kx1,8Kx2,4Kx4,2Kx8,1Kx16和512x32六种不同的工作模式.基于不同的配置选择,此SRAM可以配置为双端口SRAM,单端口SRAM,ROM,FIFO,大的查找表或移位寄存器,本文完整介绍了该SRAM的设计方法,重点介绍了一种新颖的存储单元电路结构:三端口存储单元,以及用于实现可重构功能的电路的设计方法.

纳米非晶硅(na-Si:H)P-i-n太阳电池

该文报道了通过适当氢稀释(RH=15)和合适的衬底温度(Ts=170℃)下,用PECVD制备得到的宽带隙氢化纳米非晶硅(na-Si:H)薄膜,并将其用作pin太阳电池的本征层.经过电池结构和工艺条件的优化设计,在p/i,i/n界面插入渐变带隙缓冲层,制备出了glass/ITO/p-a-SiC:H/i-na-Si:H/n-nc-Si:H/Al结构的pin太阳电池.电池初始开路电压(Voc)高达0.94V,同时还能保证0.72的填充因子(FF).光电转换效率(Eff)达到8.35%(AM1.5,100mW/cm2).

原子氢辅助分子束外延生长对GaAs材料性能的改善

利用深能级瞬态谱(DLTS)研究了常规分子束外延和原子氢辅助分子生长的掺杂Si和Be的GaAs同质结构样品中缺陷的电学特性。发现原子氢辅助分子束外延生长的样品中缺陷的浓度与常规分子束外延生长的样品相比有明显的降低，这可解释为生长过程中原子氢对缺陷的原位中和与钝化作用。

Improvement of CMOS SOS devices characteristics by a modified solid phase epitaxy

CMOS/SOS devices have lower carriers mobility and higher channel leakage current than bulk silicon CMOS devices. These mainly results from the defects of heteroepitaxial silicon film, especially from the defects near Si-Sapphire interface. This paper describes the experiment results of CMOS/SOS devices characteristics improved by a better epitaxial silicon quality which is obtained by a modified solid phase epitaxy.

The diphasic nc-Si/a-Si : H thin film with improved medium-range order

A series of silicon film samples were prepared by plasma enhanced chemical vapor deposition (PECVD) near the threshold from amorphous to nanocrystalline state by adjusting the plasma parameters and properly increasing the reactions between the hydrogen plasma and the growing surface. The microstucture of the films was studied by micro-Raman and Fourier transform infrared (FTIR) spectroscopy. The influences of the hydrogen dilution ratio of silane (R-H = [H-2]/[SiH4]) and the substrate temperature (T-s) on the microstructural and photoelectronic properties of silicon films were investigated in detail. With the increase of RH from 10 to 100, a notable improvement in the medium-range order (MRO) of the films was observed, and then the phase transition from amorphous to nanocrystalline phase occurred, which lead to the formation of diatomic hydrogen complex, H-2* and their congeries. With the increase of T-s from 150 to 275 degreesC, both the short-range order and the medium range order of the silicon films are obviously improved. The photoconductivity spectra and the light induced changes of the films show that the diphasic nc-Si/a-Si:H films with fine medium-range order present a broader light spectral response range in the longer wavelength and a lower degradation upon illumination than conventional a-Si:H films. (C) 2004 Elsevier B.V. All rights reserved.

鄂尔多斯地区锦鸡儿资源化途径与关键技术

锦鸡儿灌木适生于鄂尔多斯高原，资源丰富，萌发力强，粗蛋白和钙含量高，锦鸡儿的饲用化开发是当地羊绒业实现可持续发展的根本对策之一。为此进行了锦鸡儿资源评估并应用正交、均匀和配方设计对康氏木霉，黑曲霉产酶发酵和锦鸡儿同步酶解发酵进行了实验研究。结果表明：（1）锦鸡儿叶部约占地上干生物质的20％；4年是锦鸡儿生长的临界点，4年后粗纤维含量骤升，木质化程度加剧。故锦鸡儿应在花期后、落叶前的深秋、每4年贴地平茬一次。（2）开发出康氏木霉纤维素酶、黑曲霉果胶酶的优化产酶培养基配方与固态发酵工艺，二者放大发酵复合酶的活力超过国内同类商品，成本仅537.16元／（tDM）、1072.10元／（tDM）。舍饲时添加复合酶的山羊仅增重可增收138元（年·只）。（3）在同步酶解发酵锦鸡儿生物质时，乳酸菌长期发酵产生的乳酸会降低pH值并对酶解粗纤维产生抑制；复合酶中FPA:CMCase：棉花酶： β-glucosidase活力比以0.6:1:0.3:1为宜。（4）中间锦鸡儿资源集中在干草原区，4年轮流平茬时每年收获的生物质可供146万只羊越冬，经复合酶发酵后能满足191万只羊越冬期间对粗蛋白的需求。本研究有助于西部不发达牧区实现社会、经济和环境的可持续发展。