改进型硅微振动轮式陀螺仪有限元模型与结构性能研究

由于改进型硅微振动轮陀螺仪的结构性能要求和特殊的制造工艺,在设计阶段必须对其进行详细的结构性能分析.本文建立了该陀螺仪的三维有限元模型,分析计算了其基本模态.通过研究其谐响应,确定了频率、振幅和灵敏度的关系.     

改进VGG网络的多聚焦图像的融合方法

为更好地保留原图像信息,提高图像融合性能,提出一种改进VGG卷积神经网络与边缘像素统计特征相结合的融合算法。首先,该算法将完整图像拆分成图像块,以图像块的预处理来获取较高的图像分类,精度达到0.985以上,以改进的VGG卷积神经网络来加快模型收敛速度,当图像块输入到网络当中,可以初步得到二分类的权值矩阵。其次,在高频细节部分,对于左聚焦图像和右聚焦图像的清晰模糊模块分别进行模糊化处理,根据像素点之间的统计特征经阈值分割后得到有明显边界的权值矩阵。最后,结合两次分割的权值矩阵,通过加权求和的融合策略,得到处处清晰的聚焦图像。为说明算法有效性,在实验部分展示其融合主观视觉效果图与信息熵等客观评价,该算法对比其他算法表现突出,可较好地保留原图像的信息。     

Defects in Statically Unstable Solids: The Case for Cubic Perovskite α-CsPbI3

High-temperature phases of solids are often dynamically stable only. First-principles study of point defects in such solids at 0 K is prohibited by their static instability, which results in random structures of the defect-containing supercell so that the total energy of the supercell is randomly affected by structural distortions far away from the defect. Taking cubic perovskite α-Cs Pb I3 as an example, we first present the problem incurred by the static instability and then propose an approac...     

The dual role of multiple-transistor charge sharing collection in single-event transients

As technologies scale down in size, multiple-transistors being affected by a single ion has become a universal phenomenon, and some new effects are present in single event transients (SETs) due to the charge sharing collection of the adjacent multiple-transistors. In this paper, not only the off-state p-channel metal-oxide semiconductor field-effect transistor (PMOS FET), but also the on-state PMOS is struck by a heavy-ion in the two-transistor inverter chain, due to the charge sharing collection and the electrical interaction. The SET induced by striking the off-state PMOS is efficiently mitigated by the pulse quenching effect, but the SET induced by striking the on-state PMOS becomes dominant. It is indicated in this study that in the advanced technologies, the SET will no longer just be induced by an ion striking the off-state transistor, and the SET sensitive region will no longer just surround the off-state transistor either, as it is in the older technologies. We also discuss this issue in a three-transistor inverter in depth, and the study illustrates that the three-transistor inverter is still a better replacement for spaceborne integrated circuit design in advanced technologies.     

石斛属植物中石斛碱类成分的波谱学特征

石斛属（Dendrobium Sw.）植物中的石斛碱类（dendrobines）倍半萜生物碱（sesquiterpenoid alkaloids）以其独特的结构和显著的生理活性而受到广泛关注．本文对石斛碱类化合物的结构特点及波谱学特征，包括紫外光谱（UV）、红外光谱（IR）、质谱（MS）、核磁共振（NMR）波谱等进行总结，并归纳石斛碱类成分的结构解析方式，为其深入研究与开发提供参考依据．     

“正确证明”有瑕疵

第32届IMO试题如图1,P为△ABC内任意一点,求证:∠1,∠2,∠3中至少有一个不大于30°本刊2009年第10期高群安老师给出错误证明后,笔者在本刊2010年第6期予以纠正如下:证明假设∠1,∠2,∠3都大于30°,设P点到三角形三边AB、BC、CA的距离分别为p,q,r,则PA<2p,PB     

涨落耗散定理概述

本文从一个最早的例子——Einstein关系,到Callen和Welton及Kubo公式,简述了涨落耗散定理形成和发展的历史,阐明了这个在统计物理学中占有重要地位的定理的物理实质,并列举了它在各个领域一些应用实例,通过这些具体例子,记述了涨落耗散定理与线性响应理论、广义Langevin方程、非平衡统计力学等的关系。     

远离平衡问题及其描述的理论和方法概述

本文简要阐述了耗散结构、混沌、外场驱动下的耗散系统非线性动力学等远离平衡和非线性问题,及描述这些问题的各种宏观、半宏观及非平衡统计物理的理论和方法。     

6-甲氧基-1,2,3,9-四氢-4H-咔唑-4-酮肟的一锅合成

报道了6-甲氧幕-1,2,3,9-四氢-4H-咔唑-4-酮肟(3b)的一锅合成法,将Fischer吲哚合成与肟化两步反应并为一步,可简化操作,提高收率.反应可以在弱碱性且温度温和的条件下一锅合成,是由于肟化使Fischer吲哚环合变得容易,羰基与肟基在互变异构方向上的差别是影响环合反应的关键因素.