镁铁双羟基复合金属氧化物的可控合成及晶面生长特征研究

采用成核 /晶化隔离法合成镁铁双羟基复合金属氧化物MgFe LDH ,考察了Mg∶Fe摩尔比对MgFe LDH晶形的影响 ,探讨了晶化温度及晶化时间对晶面生长选择性及晶粒尺寸的影响规律 .结果表明 ,随Mg∶Fe摩尔比增大 ,层板阳离子排列更为规整 .晶化温度对晶粒尺寸的影响显著大于晶化时间的影响 .晶化温度相同 ,随晶化时间延长 ,MgFe LDH的晶体结构趋于完整 ,晶粒尺寸变化不大 ;晶化时间相同 ,随晶化温度升高 ,晶体结构趋于完整 ,晶粒尺寸明显增大 .所得到的MgFe LDH沿a轴方向的晶粒尺寸对晶化温度变化的敏感程度远大于对晶化时间变化的敏感程度 ,但总是沿a轴方向的晶粒尺寸大于沿c轴方向的尺寸 ,即 [110 ]晶面的生长速率比[0 0 2 ]晶面的生长速率快     

近红外光谱法的若干应用实例

通过ＰＧＥ和ｍＰＤＡ体系反应前后的近红外和中红外光谱图的对比，说明对于含Ｎ─Ｈ和Ｏ─Ｈ官能团的物质近红外光谱显示出中红外光谱无法比拟的优越性。本研究介绍了近红外光谱对Ｎ─Ｈ、Ｏ─Ｈ、ＣＨ＿２─ＣＨ─等官能团分析的应用实例，以及如何应用近红外光谱法研究金属氧化物的表面羟基与其催化活性的关系。     

用发射光谱分析法检测地膜中金属杂质含量

本文描述农用薄膜中Ａｌ、Ｆｅ、Ｍｇ、Ｃａ、Ｓｉ、Ｃｕ、Ｔｉ杂质元素的发射光谱分析法，该方法直接压样于石墨电极中，简便，快速，取得了满意的结果。     

Sub-nanosecond silicon-on-insulator optical micro-ring switch with low crosstalk

<正>We demonstrate a sub-nanosecond electro-optical switch with low crosstalk in a silicon-on-insulator(SOI) dual-coupled micro-ring embedded with p-i-n diodes.A crosstalk of -23 dB is obtained in the 20-μm-radius micro-ring with the well-designing asymmetric dual-coupling structure.By optimizations of the doping profiles and the fabrication processes,the sub-nanosecond switch-on/off time of400 ps is finally realized under an electrical pre-emphasized driving signal.This compact and fast-response micro-ring switch,which can be fabricated by complementary metal oxide semiconductor(CMOS) compatible technologies,have enormous potential in optical interconnects of multicore networks-on-chip.     

Band Structures of Metal-Oxide Capped Graphene： A First Principles Study

We perform a first-principles calculation based on density functional theory to investigate the interface between single layer graphene and metal oxides. Our study reveals that the monolayer graphene becomes semiconducting by single crystal SiO2 and Al2O3 contact, with energy gaps to - 0.9 and - 1.8 eV, respectively. We find the gap originates from the breakage of π bond integrity, whose extent is related to the interface atom configuration. We believe that our results highlight a promising direction for the feasibility to apply large scale graphene layers as building blocks in future electronics devices.     

Quantum Mechanical Study on Tunnelling and Ballistic Transport of Nanometer Si MOSFETs

Using self-consistent calculations of million-atom SchrSdinger-Poisson equations, we investigate the I-V characteristics of tunnelling and ballistic transport of nanometer metal oxide semiconductor field effect transistors （MOSFET） based on a full 3-D quantum mechanical simulation under nonequilibtium condition. Atomistic empirical pseudopotentials are used to describe the device Hamiltonian and the underlying bulk band structure. We find that the ballistic transport dominates the I-V characteristics, whereas the effects of tunnelling cannot be neglected with the maximal value up to 0.8mA/μm when the channel length of MOSFET scales down to 25 nm. The effects of tunnelling transport lower the threshold voltage Vt. The ballistic current based on fully 3-D quantum mechanical simulation is relatively large and has small on-off ratio compared with results derived from the calculation methods of Luo et al.     

A low specific on-resistance SOI MOSFET with dual gates and a recessed drain

A low specific on-resistance(Ron,sp) integrable silicon-on-insulator(SOI) metal-oxide semiconductor field-effect transistor(MOSFET) is proposed and investigated by simulation.The MOSFET features a recessed drain as well as dual gates,which consist of a planar gate and a trench gate extended to the buried oxide layer(BOX)(DGRD MOSFET).First,the dual gates form dual conduction channels,and the extended trench gate also acts as a field plate to improve the electric field distribution.Second,the combination of the trench gate and the recessed drain widens the vertical conduction area and shortens the current path.Third,the P-type top layer not only enhances the drift doping concentration but also modulates the surface electric field distributions.All of these sharply reduce Ron,sp and maintain a high breakdown voltage(BV).The BV of 233 V and Ron,sp of 4.151 mΩ·cm2(VGS = 15 V) are obtained for the DGRD MOSFET with 15-μm half-cell pitch.Compared with the trench gate SOI MOSFET and the conventional MOSFET,Ron,sp of the DGRD MOSFET decreases by 36% and 33% with the same BV,respectively.The trench gate extended to the BOX synchronously acts as a dielectric isolation trench,simplifying the fabrication processes.     

Lead zirconate titanate behaviors in an LDMOS

The behaviors of lead zirconate titanate (PZT) deposited as the dielectric for high-voltage devices are investigated experimentally and theoretically. The devices demonstrate not only high breakdown voltages above 350 V, but also excellent memory behaviors. A drain current-gate voltage (ID-VG) memory window of about 2.2 V is obtained at the sweep voltages of ±10 V for the 350-V laterally diffused metal oxide semiconductor (LDMOS). The retention time of about 270 s is recorded for the LDMOS through a controlled ID-VG measurement. The LDMOS with memory behaviors has potential to be applied in future power conversion circuits to boost the performance of the energy conversion system.     

时间延迟积分型面阵CMOS图像传感器MTF速度失配模型研究

研究了时间延迟积分型面阵互补金属氧化物半导体(CMOS)图像传感器调制传递函数(MTF)速度失配特性,在分析累加级数、像素尺寸、镜头放大倍数、行周期及电机运动速度失配等影响因素的基础上,建立了MTF速度失配模型。基于现场可编程门阵列(FPGA)开发板,搭建面阵CMOS图像传感器实现线阵时间延时积分(TDI)的CMOS测试系统。实验结果表明,在光强为3lx,速度失配M(ΔV/V)<2,8级时间延迟积分与面阵成像相比,MTF值提高50%;当累加级数为8级,速度失配满足M(ΔV/V)=2的速度失配容限时,奈奎斯特频率处的MTF值下降10%,当速度失配达到M(ΔV/V)=10时,MTF值下降35%。     

K促进的纳米片状水滑石衍生CoAlO金属氧化物催化碳烟燃烧

采用水热法合成了负载K的纳米片状水滑石衍生CoAlO金属氧化物,其表现出优异的催化碳烟燃烧活性.氢气-程序升温还原（H₂-TPR）实验结果表明,K与Co之间的相互作用提高了催化剂的氧化还原性能.X射线光电子能谱（XPS）分析结果表明,K的负载增大了表面Co²⁺/Co³⁺的比例,促进了氧空位的产生,提高了催化剂对气相氧的吸附能力.碳烟-程序升温还原（Soot-TPR）实验结果表明,K的负载增加了表面吸附氧数量.动力学实验结果表明,K的负载增加了单位质量催化剂上的活性氧数量、反应速率和转化频率（TOF）,从而提高了催化剂的本征活性.另外,碳烟颗粒可以分散在纳米片的层间,与活性位点的接触效率得到提高,也有利于提高催化碳烟燃烧活性.