一种测量RTD串联电阻的新方法

根据RTD峰值电压VP与串联电阻RS、外加电阻Rex的关系,提出一种新的测量RTD串联电阻RS的方法.实验证明该方法具有准确、简便、快速等特点.文中给出VP与RS,Rex关系的推导,RS测量原理、测量结果和与其他RS测量方法的比较.     

一种抗H．264压缩攻击的视频水印方案

提出了一种能较好地抗H．264压缩的鲁棒视频水印方法。根据H．264中DCT变换系数的分布和人眼视觉的特点,选择1帧的亮度残差分量4×4矩阵中次对角线位置上的四个中频系数嵌入水印。分析水印信息受压缩攻击出错的原因,并结合纠错编码的原理,提出了一种根据中频系数奇偶性嵌入可抗压缩的鲁棒性水印的方法,有效的提高水印的抗压缩性。试验结果表明,提出的方法对抵抗H．264压缩、准确提取水印具有显著效果。     

金属膜层对光纤表面等离子传感器的影响研究

采用SG-12SA作为镀膜设备, 研究了当金膜厚度相同的情况下, 光纤表面等离子体波传感器在有粘结层和无粘结层时的光谱特性; 当粘结层厚度相同时, 光纤表面等离子体波传感器对应不同金膜厚度的光谱特性。结果表明：对镀有同样金膜厚度的光纤表面等离子体波传感器, 纤芯与金膜之间有粘结层相对于无粘结层, 共振波长出现红移, 且共振深度减小; 对镀有同样粘结层厚度的光纤表面等离子体波传感器, 随着金膜厚度的增加, 共振波长亦逐渐发生红移。这些研究成果为以后研制性能优良的光纤传感器提供了参考, 同时为在直径为微米级的三维圆柱面上镀膜提供一定的指导意义。     

A pure spin-current injector of semiconductor quantum dots with Andreev reflection and Rashba spin-orbit coupling

We propose a four-terminal device consisting of two parallel quantum dots with Rashba spin-orbit interaction (RSOI), coupled to two side superconductor leads and two common ferromagnetic leads, respectively. The two ferromagnetic leads and two quantum dots form a ring threaded by Aharonov-Bohm (AB) flux. This device possesses normal quasiparticle transmission between the two ferromagnetic leads, and normal and crossed Andreev reflections providing conductive holes. For the appropriate spin polarization of the ferromagnetic leads, RSOI and AB flux, the pure spin-up (or spin-down) current without net charge current in the right lead, which is due to the equal numbers of electrons and holes with the same spin-polarization moving along the same direction, can be obtained by adjusting the gate voltage, which may be used in practice as a pure spin-current injector.     

国产优化300／600MW汽轮机通流部分气动设计──第一部分：设计体系与通流设计特点

本文介绍了用于大功率汽轮机通流部分气动设计的准三维／全三维设计体系。使用该设计体系把复合倾斜叶片、可控涡流型等先进的汽轮机气动设计思想，成功地应用到了３００／６００ＭＷ汽轮机的改型设计中，以期较大程度地改进机组的热力性能。     

基于5G+MEC的电站行业专网部署方案研究

随着5G正式商用以及新基建对5G应用的大力推进,5G正快速融入工业、能源、医疗等各行各业,成为推动实体经济数字化、网络化、智能化转型升级的关键驱动。主要研究5G专网在发电站领域的部署方案,探讨如何将5G技术应用于电站生产、运维各环节,助力智慧电站建设。     

基于偏振控制的Sagnac环负系数微波光子滤波器

为了克服正抽头系数低通滤波的限制,满足光载无线通信(ROF)、无线通信等系统对带通滤波器的需要,提出了一种新的负系数带通微波光子滤波器结构。系统采用了一种偏振敏感的电吸收调制器,其横向电场(TE)和横向磁场(TM)方向上具有不同的调制系数,在小信号调制下仍为线性调制。通过旋转偏振控制单元的波片,改变其快轴与TE方向的夹角,可以得到任意偏振态的转换。当偏振控制单元由两个旋光方向相反的法拉第旋光片和一个1/2波片组合时实现了负系数滤波,和一个1/4波片组合时得到了正系数滤波。     

Load adaptive start-up scheme for synchronous boost DC-DC converter

This paper presents a load adaptive soft-start scheme through which the inductor current of the synchronous boost DC-DC converter can trace the load current at the start-up stage. This scheme effectively eliminates the inrush-current and over-shoot voltage and improves the load capability of the converter. According to the output voltage, the start-up process is divided into three phases and at each phase the inductor current is limited to match the load. In the pre-charge phase, a step-increasing constant current gives a smooth rise of the output voltage which avoids inrush current and ensures the converter successfully starts up at different load situations. An additional ring oscillator operation phase enables the converter to start up as low as 1.4 V. When the converter enters into the system loop soft-start phase, an output voltage and inductor current detection methods make the transition of the phases smooth and the inductor current and output voltage rise steadily. Effective protection circuits such as short-circuit protection, current limit circuit and over-temperature protection circuit are designed to guarantee the safety and reliability of the chip during the start-up process. The proposed start-up circuit is implemented in a synchronous boost DC-DC converter based on TSMC 0.35μm CMOS process with an input voltage range 1.4-4.2 V, and a steady output voltage 5 V, and the switching frequency is 1 MHz. Simulation results show that inrush current and overshoot voltage are suppressed with a load range from 0-2.1 A, and inductor current is as low as 259 mA when the output shorts to the ground.     

一种用于语音增强的卷积门控循环网络

为了充分利用含噪语音特征来提高语音增强网络的性能,基于含噪语音在时间和频率两个维度上的相关性,本文结合卷积神经网络的局部特征提取能力和门控循环单元的长期依赖建模能力,设计了一种适用于语音增强的卷积门控循环网络.该网络采用卷积网络结构代替全连接网络结构来改进门控循环单元中的特征计算过程,从而能够更好地保留含噪语音特征中的时频结构信息.实验结果表明,与其它语音增强网络相比,本文网络在语音成分的保留和噪声成分的抑制上具有明显优势,增强后语音具有更好的语音质量和可懂度.     

共振隧穿器件及其集成技术发展趋势和研究热点

在概括了共振隧穿器件及其集成技术的特点和分析了其发展趋势的基础上,给出了该领域当前的研究热点。