纳米ZnO掺杂压敏电阻电位梯度与显微组织研究

在制备ZnO压敏电阻的原料中加入纳米级ZnO粉料，研究了纳米级粉料对ZnO压敏电阻的压敏电位梯度的影响，并对其微观组织进行了分析研究，从理论上探讨了纳米ZnO影响ZnO压敏电阻压敏电位梯度与组织的机理．研究结果表明，压敏电阻中加入纳米ZnO后，其压敏电位梯度显著提高，纳米ZnO(质量分数)在0-30%的成分范围内，随着纳米ZnO含量的增加，ZnO压敏电阻的压敏电位梯度明显提高．其原因是纳米ZnO加入到ZnO压敏电阻中，使晶粒尺寸减小所致．     

新型低功耗128×128红外读出电路设计

文中介绍了一种新型的128×128红外读出电路中的低功耗设计,包括像素级和列读出级两部分.在像素级设计中,提出了一种新型四像素共用反馈放大器(Quad-Share Buffered Injection,QSBDI)的结构:每个像素的平均功耗为500nW,放大器引入的功耗降低了30%,同时使像素FPN只来源于局部失配.列读出级采用新型主从两级放大列读出结构,其中主放大器完成电荷到电压的转换,从放大器驱动输出总线来满足一定的读出速度.通过SPICE仿真发现,与传统列电荷放大器结构相比,新型结构可节省60%的功耗.     

pMOSFET中栅控产生电流的衬底偏压影响研究

研究了pMOSFET中栅控产生电流(GD)的衬底偏压特性。衬底施加负偏压后,GD电流峰值变小;衬底加正向偏压后,GD电流峰值增大。这归因于衬底偏压VB调制了MOSFET的栅控产生电流中最大产生率,并求出了衬底偏压作用系数为0.3。考虑VB对漏PN结的作用,建立了包含衬底偏压的产生电流模型。基于该模型的深入分析,很好地解释了衬底负偏压比衬底正偏压对产生电流的影响大的实验结果。     

低相干光干涉法延时测量中的误差分析

低相干光干涉法通过测量宽谱光通过待测器件之后的相位变化得到其相对延时量。采集宽谱光时域干涉数据,利用傅里叶变换提取出频域相位信息后再进行相位展开、多项式拟合处理,所得相位曲线对频率求导可得待测延时曲线。延时测量误差来源于干涉信号强度误差和纯相位误差。理论分析和仿真计算表明,延时误差与相位误差成正比;强度噪声引起的相位误差与噪声强度成正比,且该类噪声可通过曲线拟合算法得到有效抑制。实验表明,温度等环境因素引起的纯相位误差是延时测量误差的主要因素。实验上,对约19 m光子晶体光纤于1540~1560 nm波段的相对延时进行了测量,达到了0.14 ps的精度。     

一种单层双频宽带GNSS测量型天线设计

基于单介质层结构,设计了一款双频宽带全球卫星导航系统(GNSS)测量型天线,天线采用单层高性能轻质复合材料作为双频微带天线共用的辐射介质基板。双频辐射贴片单元采用共面齿轮结构设计,并在天线单元外围设置一系列短路销钉来有效改善天线轴比带宽、低仰角辐射增益等参数,四馈点馈电技术和宽带耦合相移馈电网络的应用保证了天线相位中心稳定度更加可靠。设计结果表明,该双频天线单元大于等于5 d Bi的辐射增益带宽均大于245 MHz,高低频3 d B轴比带宽分别为-76°~76°和-116°~116°,低仰角90°增益滑落均小于11.5 d B,经实物样机对比测试分析,实测结果与仿真结果基本吻合。实测频谱显示,该天线工作频段覆盖目前在运行的四大导航系统全部工作频点,较好满足GNSS精确测量与定位系统终端设备应用需求。     

0.35μm CMOS 2.5Gb/s宽动态范围前置放大器设计

采用Chartered 0.35μm CMOS工艺设计了一种适用于光纤传输系统STM-16(2.5Gb/s)速率级的低功耗、宽动态范围的前置放大器.该前置放大器采用RGC(Regulated Cascode)结构作为输入级,同时引入消直流电路来提高光电流的过载能力.仿真结果表明,前置放大器的跨阻增益为57.0dBΩ,-3dB带宽为2.003GHz;当误码率BER为10~(-12)时,输入灵敏度为-23.0dBm,过载光电流达到800 μ A.3.3V单电源供电时,功耗仅为59.43mW.芯片面积为465 μm × 435 μm.     

连接器的介质耐电压试验

该文介绍了连接器的介质耐电压试验,重点阅述如何确定其试验条件,以保证试验的准确性和一致性,并就实验中的一些问题进行探讨.     

H型栅结构的亚微米PDSOI MOS器件的跨导双峰效应研究

A bimodal effect of transconductance was observed in narrow channel PDSOI sub-micron H-gate PMOSFETs,which was accompanied with the degeneration of device performance.This paper presents a study of the transconductance bimodal effect based on the manufacturing process and electrical properties of those devices.It is shown that this effect is caused by a diffusion of donor impurities from the NC region of body contact to the PC poly gate at the neck of the H-gate,which would change the work function differences of the polysilicon gate and substrate.This means that the threshold voltage of the device is different in the width direction,which means that there are parasitic transistors paralleled with the main transistor at the neck of the H-gate.The subsequent devices were fabricated with layout optimization,and it is demonstrated that the bimodal transconductance can be eliminated by mask modification with NC implantation more than 0.2 m away from a poly gate.     

低能量He—Ne激光血管内照射对血脂的影响

应用低能量Ｈｅ—Ｎｅ激光血管内照射外周循环血液，结果显示：与对照组相比较，Ｔ—Ｇ差异显著（Ｐ＜０．００５），Ｔ—ｃｈ与ＨＤＬ—ｃｈ差异非常显著（Ｐ＜０．０１—０．００５）．说明低能量Ｈｅ—Ｎｅ激光血管内照射，可遏制高脂血症及心脑血管病等的发生。     

Atomic Insights into the Enhanced Surface Stability in High Voltage Cathode Materials by Ultrathin Coating

Surface properties of electrode materials play a critical role in the function of batteries. Therefore, surface modifications, such as coatings, have been widely used to improve battery performance. Understanding how these coatings function to improve battery performance is crucial for both scientific research and applications. In this study the electrochemical performance of coated and uncoated LiNi_0.5Mn_1.5O₄ (LNMO) electrodes is correlated with ensemble‐averaged soft X‐ray absorption spectroscopy (XAS) and spatially resolved scanning transmission electron microscopy‐electron energy loss spectroscopy (STEM‐EELS) to illustrate the mechanism of how ultrathin layer Al₂O₃ coatings improve the cycle life of LiNi_0.5Mn_1.5O₄. Mn²⁺ evolution on the surface is clearly observed in the uncoated sample, which results from the reaction between the electrolytic solution and the surfaces of LiNi_0.5Mn_1.5O₄ particles, and also possibly atomic structure reconstructions and oxygen loss from the surface region in LiNi_0.5Mn_1.5O₄. The coating effectively suppresses Mn²⁺ evolution and improves the battery performance by decelerating the impedance buildup from the surface passivation. This study demonstrates the importance of combining ensemble‐averaged techniques (e.g., XAS) with localized techniques (e.g., STEM‐EELS), as the latter may yield unrepresentative information due to the limited number of studied particles, and sheds light on the design of future coating processes and materials.