Fabrication and characterization of groove-gate MOSFETs based on a self-aligned CMOS process

N and P-channel groove-gate MOSFETs based on a self-aligned CMOS process have been fabricated and characterized. For the devices with channel length of 140nm, the measured drain induced barrier lowering (DIBL) was 66mV/V for n-MOSFETs and 82mV/V for p-MOSFETs. The substrate current of a groove-gate n-MOSFET was 150 times less than that of a conventional planar n-MOSFET. These results demonstrate that groove-gate MOSFETs have excellent capabilities in suppressing short-channel effects. It is worth emphasizing that our groove-gate MOSFET devices are fabricated by using a simple process flow, with the potential of fabricating devices in the sub-100nm range.     

基于OpenCV的嵌入式自动捡乒乓球系统设计

为了解决在乒乓球比赛和训练中人工手动捡球的问题,从机器视觉的角度出发,综合嵌入式、图像处理和测量控制等技术,基于第三方库OpenCV设计了一种自动捡乒乓球系统。系统是以Contex-A8平台为控制核心,首先通过对云台和USB摄像头的控制获取视频信号;然后通过霍夫圆变换和SVM分类器算法识别出视频中的乒乓球,并根据质心计算出其与系统的相对位置;最后将视频信号中抽象出的位置信息传递给机械运动控制终端,控制小车和机械手将乒乓球捡起,并送到指定位置。实验结果表明本系统能够正确的检测和识别乒乓球,并对其进行定位捡取,效果良好,提高了拾取乒乓球的效率,减轻工作人员的负担。     

可调谐超导滤波器技术的研究

通过研究可调谐滤波器的基本原理,利用钛酸锶铁电薄膜介电常数随外加电场变化的特性,以铝酸镧为基片,采用多层薄膜和三次套刻两种方法设计出可调谐超导滤波器,通过外加电压实现滤波器频率的调谐。     

夸克物质中的色超导性理论简介(英文)

夸克-夸克通过单胶子交换的相互作用在其反对称态上是相互吸引的,在致密夸克物质里,这种吸引相互作用会导致费米面上的双夸克凝聚,这就是所谓的夸克配对或色超导现象。本文介绍了夸克配对或色超导现象的基本知识和一些新进展。色超导是一个对称性自发破坏现象,有非常丰富的破缺方式,我们介绍了色超导对称性及其自发破坏模式的分析方法,介绍了怎样计算色超导体两个最基本的变量:能隙和迈斯纳质量。然后我们介绍了描述色超导现象的有效理论。最后是这些理论的一个应用,即计算色超导体里的中微子发射率以及其它输运性质。本文可以作为研究夸克物质理论的入门参考资料。     

Seasonal changes in antifreeze protein gene transcription and water content of beetle Microdera punctipennis (Coleoptera, Tenebrionidae) from Gurbantonggut desert in Central Asia

Desert beetle Microdera punctipennis (Coleoptera: Tenebriondae) is a special species in Gurbantonggut Desert in Central Asia. To investigate the possible strategy it employs for cold survival, seasonal changes in supercooling point (SCP), body water content, haemolymph osmolality and antifreeze protein gene (Mpafp) expression were measured over 13 months. Our results show SCPs in M. punctipennis adults changed from -8.0°C in summer to -18.7°C in winter. During winter, adults endured modest water loss; total water decreased from 65.4 percent in summer to 55.9% in winter. Mpafp mRNAs level increased by 13.1 fold from summer to early winter, and haemolymph osmolality increased accordingly from 550 mOsm to 1486 mOsm. Correlation coefficient of Mpafp mRNAs level and SCP indicates that Mpafp mRNA explained 65.3 percent of the variation in SCPs. The correlation between Mpafp mRNA level and total water reflected an indirect influence of antifreeze protein on water content via reducing SCP.     

Analysis on skin-effect of a polymer shielded push–pull directional coupler electro-optic switch

By using the extended point-matching method, coupled mode theory, and electro-optic modulation theory, design and optimization are carried out for a polymer shielded push–pull directional coupler electro-optic switch. A novel technique and the relative formulas are presented for analyzing the influences of the skin-effect on the microwave characteristic parameters and the switching performances. Simulation results show that the voltages of the cross- and bar-states are 0 and ±2.93 V, respectively, and the coupling length is 4.139 mm. Considering the influences of the skin-effect, the cutoff switching frequency is 172 GHz, the insertion loss is in the range of 1.920–1.975 dB, the crosstalk is less than ?20 dB, and the switching time is 31.18–31.40 ps within the range of the switching frequency from 0.72 to 172 GHz. The designed switch exhibits superior characteristics including good impedance match, low switching voltage, and high cutoff switching frequency.     

Long range effect of ion irradiation on diffusion

Argon ion irradiation enhanced diffusion between Cu and Ni was found beyond the radiation effect zone in classical theory. The enhanced diffusion effect attenuates along with the distance between the diffusion zone and the radiated surface. An interpretation based on irradiation induced discrete breathers was employed as a possible mechanism.     

脉冲激光频域干涉技术在超快动力学物理中的应用

介绍了一种具有fs时间分辨力的超短脉冲激光频域干涉测试技术,详细论述了该技术的工作原理和系统构成,指出传输时间差和相位差是影响频域干涉条纹周期的主要因素。采用脉冲激光频域干涉仪测量了200 nm厚度铝膜在波长800 nm、单脉冲能量0.7 mJ、脉宽35 fs脉冲激光作用下的运动速度剖面。在单次飞秒脉冲激光作用下,铝膜自由面的运动速度峰值可达960 m/s,速度剖面的上升前沿小于5.77 ps,表明脉冲激光频域干涉技术可用于测量材料在超快脉冲激光作用下的冲击动力学参数。     

含有格点势的一维Fibonacci链热传导性质的研究

用传输矩阵的方法,研究了格点势(on-site势)对一维Fibonacci链的热传导性质(透射系数、Lyapunov指数及热导率κ)的影响.研究结果表明:当固定原子质量比和力作用常数比时,随着格点势的增大,低频区域的透射系数减小,对应的Lyapunov指数增大,透射谱向高频方向移动.同时,格点势越大,同样大小的体系对应的κ越小,当格点势足够大时,κ会趋近零.在热导率κ对振动频率ω²作图中,κ呈现台阶式缓慢上升的趋势,且在高频     

Energy band structure of spin-1 condensates in optical lattices

The energy band structure of spin-1 condensates with repulsive spin-independent and either ferromagnetic or antiferromagnetic spin-dependent interactions in one-dimensional (1D) periodic optical lattices is discussed. Within the two-mode approximation, Bloch bands of spin-1 condensates are presented. The results show that the Bloch bands exhibit a complex structure as the atom density of m F=0 hyperfine state increases: bands splitting, reversion, intersection and loop structure are excited subsequently. The complex band structure should be related to the tunneling and spin-mixing dynamics.