Ba6-3xNd8+2xTi18O54陶瓷的微波合成及低温烧结

采用微波加热法于1 100℃保温30 min(升温速率为20℃/min)合成Ba6-3xNd8+2xTi18O54(x=0.30～0.75,BNT)陶瓷粉末,再添加质量分数45％的B2O3-SiO2-CaO-MgO( BM)玻璃,在马弗炉中于900℃烧结2h制得BNT陶瓷.研究了所制陶瓷的微观结构及性能.结果表明:微波...     

北京54坐标系向国家2000大地坐标系的转换

2000国家坐标系统提高了测量的绝对精度,并且可以快速获取精确的三维地心坐标,能够提供高精度、地心、实用、统一的大地坐标系,自此以后的测量成果要求坐标系统采用2000国家大地坐标系,本文就北京54坐标系和2000国家大地坐标系原理和转换方法进行简单的分析。     

山东省不同年代主要栽培小麦品种(系)高分子量谷蛋白亚基分布

用SDS－PAGE法鉴别了山东省从50年代至今推广的106个小麦品种（系）的HMW－GS组成。结果表明：山东省小麦品种（系）高分子量谷蛋白亚基（HMW－GS）组成以1Anu11或1A1，1Bx＋1By9或1Bx7＋1By8，1Dx2＋1Dy12为主，不同年代间亚基的分布具有一定特点，研究过程中还发现了一些较为罕见的亚基和亚基组合。针对以上结果，对山东省今后小麦品质的改良提出了几点看法。     

一种新的造血干细胞获取方法的建立

目的建立一种新的造血干细胞获取方法,为临床应用提供实验依据。方法将明胶海绵移植到小鼠后肢的大腿内侧肌间隙,12 d后分离明胶海绵中的迁移细胞。采用流式细胞术和免疫荧光法检测迁移细胞和骨髓细胞中CD34+、Sca-1+和CD34+Sca-1+细胞的表达,利用体外造血克隆分析迁移细胞和骨髓细胞中造血克隆的密度。结果迁移细胞的数量在移植12 d时达最大;迁移细胞中CD34+、Sca-1+和CD34+Sca-1+细胞的比例明显高于骨髓细胞(P<0.05),造血克隆比例也明显高于骨髓(P<0.01)。结论利用生物材料明胶海绵成功建立了一种高效的造血干细胞获取方法,可实现自体细胞治疗。     

基于坐标定位文件的不同坐标系下影像坐标一体化处理应用研究

当前很多测绘单位北京54、西安80及国家2000坐标系数据相互并存,这就造成数据在不同坐标下相互转换问题,特别是影像数据。为了节约数据转换成本,本文提出基于坐标定位文件的不同坐标系下正射影像的一体化处理,其基本思路在于直接对影像定位的坐标文件进行转换,通过前端正确显示影像位置,其特点是原理简单易于实现,不需要复杂的数据转换。     

An analytical subthreshold current modeling of cylindrical gate all around (CGAA) MOSFET incorporating the influence of device design engineering

An analytical model of CGAA MOSFET incorporating material engineering, channel engineering and stack engineering has been proposed and verified using ATLAS 3D device simulator. A comparative study of short channel effects for various device structures has also been carried out incorporating the effect of drain induced barrier lowering (DIBL), threshold voltage lowering and degradation of subthreshold slope. The effectiveness of applying the three region doping profile concept in the channel such as high-medium-low and low-high-low and its comparison with Gaussian doping profile to the cylindrical GAA MOSFET has been examined in detail. Reduced SCEs have been evaluated in combined designs i.e. TM–GC–GS, GCGS and DM–GC–GS. Out of several design engineering, GC–GS CGAA gives nearly ideal subthreshold slope whereas TM–GC–GS CGAA provides overall superior performance to reduce SCEs in deep nano-meter. The results so obtained are in good agreement with the simulated data which validate the model.     

Simplified models for the performance evaluation of desiccant wheel dehumidification

In the present communication, simple models have been presented to evaluate the performance of rotary desiccant wheels based on different kind of solid desiccants e.g. silica gel and LiCl. The first part of the paper presents ‘Model 54’ which is developed for silica gel desiccant rotor. The model has been derived from the interpolation of experimental data obtained from the industry and the correlations have been developed for predicting outlet temperature and absolute humidity. The ‘Model 54’ consists of 54 coefficients corresponding to each correlation for outlet absolute humidity and temperature and it is found that the model predicts very well the performance of silica gel desiccant rotor (Type-I). In the second part of the paper, a psychrometric model has been presented to obtain relatively simple correlations for outlet temperature and absolute humidity. The developed psychometric model is based on the correlations between the relative humidity and enthalpy of supply and regeneration air streams. The model is used to predict the performance of three type of desiccant rotors manufactured by using different kind of solid desiccants (Type I, II and III). The model is tested corresponding to a wide range of measurement data. The developed psychometric model is simple in nature and able to predict very well the performance of different kind of desiccant rotors. Copyright © 2002 John Wiley & Sons, Ltd.     

契伯格-萨克斯顿方法反演相位的二次驱动改进研究

契伯格-萨克斯顿(GS)方法在反演相位时,其反演结果并不唯一。通过数值模拟,对GS方法用于反演激光光波相位的唯一性问题进行了研究,提出了一种对GS方法做二次驱动改进的新方法,并对经过改进前后模拟得到的反演结果及其误差特性曲线进行了比较。结果说明,改进的新方法不仅能够克服绝大多数相位的不确定性,反演结果准确性强,而且还加快了收敛速度。     

TMS320C54x DSP在线烧写FLASH存储器并实现自举引导的方法

通过一个完整的实例,详细阐述了TMS320C54x系列DSP芯片在线烧写FLASH存储器,并实现自举引导的方法。给出了硬件连接方案和完整的C语言烧写程序。