功率器件、电路和系统用的计算机辅助设计技术的进展

最近10年,计算机辅助设计技术(TCAD)的应用已在工业界和学术界普及。计算机硬件和软件迅猛发展和数值算法用的物理模型的精度、速度和鲁棒性显著提高,使TCAD作为晶片加工和计量的补充实验方法,成为降低成本的有效技术。     

日将试验最大风力发电设备

日本三菱重工将于年末在横浜制作所金泽工厂安装使用日本最大风车的风力发电设备，并进行实证试验。     

Evaluation of a multimode fiber optic low coherence interferometer for path length resolved Doppler measurements of diffuse light

The performance of a graded index multimode fiber optic low coherence Mach-Zehnder interferometer with phase modulation is analyzed. Investigated aspects were its ability to measure path length distributions and to perform path length resolved Doppler measurements of multiple scattered photons in a turbid suspension of particles undergoing Brownian and translational motion. The path length resolution of this instrument is compared with a system using single mode fibers for illumination and detection. The optical path lengths are determined from the zero order moment of the phase modulation peak in the power spectrum. The weighted first moment, which is equal to the average Doppler shift, shows a linear response for different mean flow velocities within the physiological range.     

Spectroscopic and structural properties of MgAl_2O_4:Nd~(3+) nanopowders and ceramics

The structural and spectroscopic properties of MgAl2O4:1%Nd3+ spinel nanocrystals and ceramics were measured and analyzed. Ceramics were prepared from the above mentioned spinel nanocrystals and undoped commercial spinel powder, using the spark plasma sintering(SPS) method. Properties of the obtained ceramics strongly depended on the SPS conditions. The samples were not homogeneous and possessed defects and pores. The most transparent ceramics had 60% transparency at 1000 nm.     

Ultralow feeding gas flow guiding growth of large-scale horizontally aligned single-walled carbon nanotube arrays

On the basis of the rational analysis about the fluidic property of the system, an ultralow gas flow chemical vapor deposition (CVD) strategy was designed to prepare large-scale horizontally aligned ultralong single-walled carbon nanotube (SWNT) arrays. SWNT arrays could be well obtained under extremely low feeding flow of 1.5 sccm in a 1 in. quartz tube reactor. It was confirmed that the tubes grew floatingly and could cross microtrenches or climb over micro-obstacles in ultraslow gas flow. SWNTs arrays also could be formed no matter the substrate was placed vertically or upside down. The growth mechanism was discussed. Both the buoyancy effect induced by gas temperature/density difference and gas flow stability played dominant roles. More attractively, simultaneous batch-scale preparation of SWNT arrays was realized by the ultralow gas flow strategy. This new strategy turns to be more abstemious, efficient, promising, and flexible compared with the high gas flow rate fast-heating CVD processes.     

Fluorescence recovery assay for the detection of protein-DNA binding

We report a novel and straightforward fluorescence recovery assay which enables the detection of protein-DNA interactions and simultaneously determines relative binding affinities of sequence-specific DNA-binding proteins for a variety of DNA sequences in a multiplexed format. The detection of protein-DNA binding is accomplished by monitoring fluorescence recovery during exonuclease digestion of DNA sequences that are modified with fluorophore-quencher pairs. Retardation of fluorescence recovery occurs with binding of the protein to the putative DNA binding element, which arrests exonuclease digestion. The assay detects protein-DNA binding in a homogeneous solution simply, quickly, and reliably without using radioisotopes. Multiplexing is possible by labeling different DNA sequences with spectrally distinct dyes, allowing simultaneous analysis of experimental and control binding reactions in the same mixture.     

Large-scale graphene transistors with enhanced performance and reliability based on interface engineering by phenylsilane self-assembled monolayers

In this letter, we report the dielectric/graphene interface physics and engineering of large-scale, chemical vapor deposited (CVD) graphene transistors by self-assembling a molecular-scale organosilane monolayer onto the dielectric surface. We show that phenyl-alkyl-terminated self-assembled monolayers (SAM) at the dielectric/graphene interface consistently improve the graphene device performance and reliability. The extrinsic field-effect mobility of large-scale CVD graphene transistors on the phenyl-SAM engineered dielectric is currently up to 2500 cm(2)/(V s) at room temperature, considerably higher than the counterparts without the SAM. In addition, significant reduction on the bias stress instability and hysteresis is achieved by the SAM-based interface engineering. Further analysis reveals that charge injection from graphene to the dielectric/graphene interface dominates the observed hysteresis behavior. For both graphene transistors with and without SAMs, the bias stress stability, that is, Dirac point shift under bias stress, is well described by the stretched exponential model with its fitting parameters clearly indicating different interface properties.     

Application of selective implantation in Al0.5Ga0.5As/In0.25Ga0.75As/GaAs pseudomorphic single quantum wire structures

A pseudomorphic Al0.5Ga0.5As/In0.25Ga0.75As/GaAs asymmetric quantum wire (QWR) structure was grown on GaAs V-grooved substrate by low pressure metal organic vapor phase epitaxy. The formation of crescent shaped QWRs at the bottom of the V-grooves was confirmed by both transmission electron microscopy and photoluminescence (PL) spectra. The temperature dependence of PL spectra demonstrated a fast decrease of the sidewall quantum well PL intensity with increasing temperature, which originates from relaxation of carriers from well to wire region. The self-aligned dual implantation technique was successfully used to selectively disable the adjacent quantum structures. Decrease of the PL intensity of QWR at 8 K was observed after selective implantation, which resulted from a decreased number of carriers relaxed from adjacent quantum structures.     

移动通信网络干扰类型分析与治理探索

本文介绍了移动通信网络干扰的类型、产生原因、解决方案及效果,为整治移动通信网络干扰提供了可行性方案.