Two-dimensional analytical models for asymmetric fully depleted double-gate strained silicon MOSFETs

This paper develops the simple and accurate two-dimensional analytical models for new asymmetric double-gate fully depleted strained-Si MOSFET. The models mainly include the analytical equations of the surface potential, surface electric field and threshold voltage, which are derived by solving two dimensional Poisson equation in strained-Si layer. The models are verified by numerical simulation. Besides offering the physical insight into device physics in the model, the new structure also provides the basic designing guidance for further immunity of short channel effect and drain-induced barrier-lowering of CMOS-based devices in nanometre scale.     

ITER遥控运输车支撑腿的设计与分析

借助虚拟样机技术为ITER遥控运输车设计了一种全新概念的支撑腿。该支撑腿能承受50t重的载荷,并能在行程150mm内任意调整高度。机械动态仿真和有限元分析的结果表明,设计的机构不仅完全实现了需要的功能,且还具有载荷恒定、控制变量呈现线性关系等良好特征。     

The study on two-dimensional analytical model for gate stack fully depleted strained Si on silicon-germanium-on-insulator MOSFETs

Based on the exact resultant solution of two-dimensional Poisson's equation in strained Si and Si_{1 - X}Ge_X layer, a simple and accurate two-dimensional analytical model including surface channel potential, surface channel electric field, threshold voltage and subthreshold swing for fully depleted gate stack strained Si on silicon-germanium-on-insulator (SGOI) MOSFETs has been developed. The results show that this novel structure can suppress the short channel effects (SCE), the drain-induced barrier-lowering (DIBL) and improve the subthreshold performance in nanoelectronics application. The model is verified by numerical simulation. The model provides the basic designing guidance of gate stack strained Si on SGOI MOSFETs.     

3-((4，6-二甲基-2-嘧啶基)硫代)-丙酸和菲咯啉三元稀土配合物的晶体结构和发光性能

制备了以3-((4,6-二甲基-2-嘧啶基)硫代)-丙酸(HL)和菲咯啉(Phen)为配体的2个三元稀土配合物[Eu(L)₃(Phen)]₂·2H₂O(1)和[Tb(L)₃(Phen)]₂·2H₂O(2),并对其结构进行了表征。单晶X射线衍射分析表明它们是同构的。2个稀土离子(Ln)由4个羧酸配体桥接,形成二聚体排列。其余2个羧酸配体和Phen以双齿螯合方式与Ln配位。Ln的配位数为9,具有扭曲的单端方形反棱柱配位多面体构型。固态光致发光测试表明,这2种配合物都显示了金属中心的特征发射带。     

低温制备二氧化钛纳米薄膜及其光伏性能研究

研究一种易实现的低温合成TiO2薄膜电极的方法。实验采用氨水、盐酸和去离子水分别作为无机粘结剂、无水乙醇作为分散剂来合成TiO2浆料,重点研究了粘结剂/分散剂质量比对薄膜制备的影响。采用合成的TiO2电极进行全固态染料敏化太阳能电池的组装。综合浆料粘稠度测试、薄膜形貌表征以及电池时域/频域光电测试等结果,分析了宏观光伏特性与微观载流子输运机制。最终得到最佳的无机粘结剂/分散剂质量比,相应电池的光电转换效率达到1.45%。     

Monte Carlo simulation of indoor external exposure due to gamma-emitting radionuclides in building materials

The use of building materials containing naturally occurring radionuclides,such as ⁴⁰K, ²³⁸U, ²³²Th and their progeny, could lead to external exposures to the residents of such buildings. In this paper, a set of models are constructed to calculate the specific effective dose rates (the effective dose rate per Bq/kg of ⁴⁰K, the ²³⁸U series, and the ²³²Th series) imposed on residents by building materials with the MCNPX code. The effect of chemical composition, position concerned in the room and thickness as well as density of material is analyzed. In order to facilitate more precise assessment of indoor external dose due to gamma-emitting radionuclides in building materials, three regressive expressions are proposed and validated by measured data to calculate specific effective rates for ⁴⁰K, the ²³⁸U series and the ²³²Th series, respectively.     

快速毛细管气相色谱分析白酒中的香味成分

本文建立了快速毛细管气相色谱法,在10 min内分离了白酒中的香味成分,并对其中的醇、醛、酸、酯进行定性分析,对主要呈味成分己酸乙酯进行定量分析,方法重复性好,回收率较高。与常规毛细管色谱法相比,快速毛细管气相色谱法有效地缩短了分析时间,提高了白酒的分析效率。     

新型SOANN埋层SOI器件的自加热效应研究

本文提出了一个新型的SOI埋层结构SOANN (silicon on aluminum nitride with nothing),用AlN代替传统的SiO₂材料,并在SOI埋氧化层中引入空洞散热通道. 分析了新结构SOI器件的自加热效应.研究结果表明:用AlN做为SOI埋氧化层的材料, 降低了晶格温度,有效抑制了自加热效应.埋氧化层中的空洞,可以进一步提供散热通道, 使埋氧化层的介电常数下降,减小了电力线从漏端通过埋氧到源端的耦合, 有效抑制了漏致势垒降低DIBL(drain Induced barrier lowering)效应.因此,本文提出的新型SOANN结构可以提高SOI器件的整体性能,具有优良的可靠性.     

全合成机油润滑下热氧化改性TC4钛合金的摩擦学行为

通过热氧化改性技术,在TC4钛合金表面制备金红石相TiO₂氧化膜,利用XRD、拉曼、辉光光谱对氧化膜结构及成分进行了分析,利用摩擦磨损试验机考察了轻载(约1 GPa)与重载(约2 GPa)下热氧化改性前后TC4钛合金样品在5W-30全合成机油润滑下的摩擦学特性,并利用SEM和XPS对其磨损表面形貌及摩擦化学反应膜的化学成分进行了分析. 结果表明:热氧化改性后,TC4钛合金表面形成具有氧化层和扩散层的双层结构. 在油润滑条件下,与未处理的TC4钛合金表面相比,经过热氧化改性的TC4合金表现出优异的减摩抗磨性能,摩擦系数在轻载和重载条件下分别降低了75%和80%,磨损率均下降了近两个数量级. 其原因在于TC4合金热氧化改性后在表面形成的金红石相TiO₂氧化膜提高了表面硬度,同时改善了润滑油在表面的润湿,并可促进润滑油中抗磨极压添加剂在接触区表面形成含磷的摩擦化学反应膜,从而极大地提高了摩擦学特性.      

银铜钛膏状钎料钎焊石墨和铜合金接头的微观组织及性能

利用银铜钛(Ag-Cu-Ti)膏状钎料采用真空钎焊的方法对两种不同石墨和铜合金进行钎焊连接实验,研究了钎焊温度、中间缓冲层、母材尺寸等工艺参数对接头性能的影响。采用自行设计模具对接头的剪切强度进行了测试,利用扫描电镜和配带的X射线能谱分析仪分析了接头界面组织形貌及元素物相成分。研究结果表明：当钎焊温度为910℃,保温时间10min时,Ag-Cu-Ti膏状钎料能够与石墨和无氧铜两侧母材形成良好的结合界面;与GA石墨相比,阿泰克石墨与无氧铜接头强度更高;采用1mm无氧铜做中间缓冲层钎焊石墨和铬锆铜时,能有效缓解钎焊热应力,接头强度有明显提高。