Numerical and analytical investigations for the SOI LDMOS with alternated high-k dielectric and step doped silicon pillars

This paper presents a new silicon-on-insulator(SOI) lateral-double-diffused metal-oxide-semiconductor transistor(LDMOST) device with alternated high-k dielectric and step doped silicon pillars(HKSD device). Due to the modulation of step doping technology and high-k dielectric on the electric field and doped profile of each zone, the HKSD device shows a greater performance. The analytical models of the potential, electric field, optimal breakdown voltage, and optimal doped profile are derived. The analytical results and the simulated results are basically consistent, which confirms the proposed model suitable for the HKSD device. The potential and electric field modulation mechanism are investigated based on the simulation and analytical models. Furthermore, the influence of the parameters on the breakdown voltage(BV) and specific on-resistance(R_on,sp) are obtained. The results indicate that the HKSD device has a higher BV and lower R_on,sp compared to the SD device and HK device.     

An investigation on the magneto-optic properties of terbium gallium garnet under high magnetic field

The superexchange interaction on a magnetic ion may be represented by an effective field H_m = $\lambda$M in some paramagnetic materials, here λ is the coefficient of effective field and M = $\chi$H_e with $\chi$ being the magnetic susceptibility and H_e being the applied field. The variation of the equivalent $\lambda_{\chi}$with the dynamic applied field is given and the crystal field-splitting levels of the excited configuration 4f⁷5d¹ of the Tb³⁺ ion are calculated in the Tb₃Ga₅O₁₂. By means of the effective field H_m and the applied field H_e, the Faraday rotation of Tb₃Ga₅O₁₂ at 6 K and 41 K, under the high magnetic field and at 0.63 μm wavelength, are presented. Our calculated results are in agreement with the experimental data.     

基于AI+MRI的影像诊断的样本增广与批量标注方法

训练样本是所有领域人工智能（AI）研发的关键因素.目前，基于人工智能+磁共振成像（AI+MRI）的影像诊断存在着训练样本的有效标注数量和类型无法满足研发需求的瓶颈问题.本文利用临床MRI设备对志愿者或阳性病例进行正常或重点病灶区的定量扫描，获取高分辨率各向同性的纵向弛豫时间（T₁）、横向弛豫时间（T₂）、质子密度（Pd）和表观扩散系数（ADC）等物理信息的多维数据矩阵，作为原始数据.开发虚拟MRI技术平台，对原始数据（相当于数字人体样本）进行虚拟扫描，实现不同序列不同参数下的多种类磁共振图像输出.选择感兴趣组织具有最好边界区分度的图像种类，经有经验的影像医生对其进行手动勾画并轨迹跟踪形成三维MASK标注矩阵，作为其他种类图像的图像勾画标注模板，从而实现低成本、高效率的MRI样本增广和批量标注.该平台以临床少量阳性病例作为输入，进行样本增广和标注，极大地减少AI对实际扫描样本的要求，降低了影像医生的精力和时间投入，极大地节省了成本，并输出了数量足够的磁共振图像，为基于AI+MRI的影像诊断研发提供低成本的训练数据解决方案.     

金纳米簇化学发光体外生物检测应用研究进展

金纳米簇是一种制备工艺简单、具有分子级尺寸和量子效应的新型发光材料,近年来在化学发光检测中得到了广泛应用,特别是较多应用于体外生物检测.本文综述了金纳米簇化学发光(含电化学发光)体系在体外生物检测中的应用进展.首先,阐释了金纳米簇的合成方法、结构、性质及其化学发光基本原理;其次,总结了国内外近年来基于该体系的体外生物检...     

金融市场波动性CARR类模型与GARCH类模型的比较研究

在CARR模型基础上提出它的衍生模型ABSCARR模型,并利用广义误差分布(GED)讨论了它们的条件残差分布问题,最后运用CARR类模型对高频金融时间序列进行了实证分析.研究结果表明:CARR及其衍生模型在高频金融时间序列的价格波动性捕捉方面具有良好的效果,而GED的引入可以很好的用于分析CARR模型具体的条件分布情况,而CARR模型的条件残差分布应该并非只有指数分布与威布尔分布两种形式.     

微波灰化电感耦合等离子发射光谱法测定初级形状塑料中催化剂残留

采用微波灰化法对聚丙烯(PP)、聚乙烯(PE)和聚对苯二甲酸乙二醇酯(PET)三种初级形状塑料进行灰化,结合差示扫描量热法(DSC)确认微波灰化的温度,并使用电感耦合等离子体发射光谱法(ICP-OES)测定催化剂残留。实验结果表明:塑料经微波灰化梯度升温,在850℃保持30min可灰化完全。方法对Al、Ca、Co、Cr、Mg、Si、Ti和Zr的检测限分别为0.24、0.12、0.08、0.03、0.03、0.35、0.01、0.02mg/kg,回收率在92.5%～116.3%之间,相对标准偏差为1.4%～9.7%。     

Experimental Properties of Optical Phase Conjugation in Cold Atoms in a Magneto-Optical Trap

We employ a sample of cold 87Rb atoms in a magneto-optical trap to study the impulse responses and spatial characters of backward conjugate waves in a four-wave mixing process. We measure the slow and superluminal group velocities of backward conjugate waves, and find the sensitive variation of the spatial mode of backward waves with the probe-pump detuning and the dependence of the reflectance on the magnetic field, while the trapping magnetic field exists.     

非线性再生散度随机效应模型的渐近性质

对非线性再生散度随机效应模型, 该文给出了类似于Barndroff-Nielson, Cox (1989)和Severin, Wong (1992)的正则条件, 基于这些正则条件和Laplace近似, 证明了该模型参数极大似然估计的存在性、强相合性和渐近正态性.     

指数族非线性模型最大似然估计的相合性和渐近正态性

本文我们提出了一些正则条件, 这些条件减弱了Zhu and Wei (1997)文中的条件. 基于所提的正则条件, 我们证明了指数族非线性模型参数最大似然估计的相合性和渐近正态性. 我们的结果可被认为是Zhu and Wei (1997)工作的进一步改进.