Photo‐Induced Charge‐Variable Conjugated Polyelectrolyte Brushes Encapsulating Upconversion Nanoparticles for Promoted siRNA Release and Collaborative Photodynamic Therapy under NIR Light Irradiation

Combination of photodynamic therapy (PDT) with small interfering RNA (siRNA) therapy has become a major strategy in cancer treatment for enhancing anticancer efficacy. However, developing nanoplatform that can promote siRNA release and collaborate with efficient PDT under NIR light irradiation is still a big challenge. Photo‐induced charge‐variable conjugated polyelectrolyte brushes encapsulating upconversion nanoparticles (UCNP@CCPEB) as an efficient nanoplatform are reported. Cationic conjugated polyelectrolyte brush (CCPEB) is synthesized through quaternary ammoniation of N‐functionalized polyfluorene brush by photodegradable 2‐nitrobenzyl‐2‐bromoacetate. CCPEB with abundant positive charges and intrinsic photosensitizer (PS) performance is good for integrating siRNA carrier and PS into one molecule. The obtained CCPEB next encapsulates upconversion nanoparticle for realizing its NIR light excitation. Agarose gel electrophoresis experiments show that UCNP@CCPEB present good stability and excellent siRNA‐loading capacity (1 mol UCNP@CCPEB to at least 32.5 mol siRNA). Under 980 nm light irradiation, UCNP@CCPEB exhibit efficient single oxygen production for PDT. Concurrently, the photoresponsive cationic side‐chain of CCPEB turns into zwitterionic chain and thus accelerates its siRNA release to 80%. In vitro and in vivo experiments show that the successful A549 tumor suppression is achieved by UCNP@CCPEB/siPlk1 complex under 980 irradiation. It is envisioned that UCNP@CCPEB can serve as an efficient platform for combining various phototherapies together.     

Comparing Through-Silicon-Via (TSV) Void/Pinhole Defect Self-Test Methods

Three methods have been proposed to test Through-Silicon-Vias (TSV) electrically prior to 3D integration. These test methods are (1) sense amplification; (2) leakage current monitor; and (3) capacitance bridge methods. These tests are aimed at detecting one or both of two failure types, pin-holes and voids. The test circuits measure capacitance and leakage current of the TSVs, and generate a 1 bit pass/fail signal. The outputs are streamed out through a scan chain. The test time is 10 μs for the leakage test and the sense amplification methods, and is 15 μs for the capacitive bridge method. All these methods can be implemented for test-before-stacking, which will increase assembled yield. Resolution, power and area of these TSV test circuits were compared. The performance of each circuit was studied at PVT corners. The IMEC TSV technology was assumed, and the designs were simulated using the 32 nm predicted device model. Without any failure, the TSV capacitance’s mean value is 37 fF, and its leakage resistance is higher than 850 MΩ. With respect to 37 fF standard capacitance, resolution for the sense amplification method is 3.3 fF (8.9%); it is 0.16 fF (0.4%) for the capacitance bridge method. Although the capacitance bridge method has relatively better resolution, it takes 4x area and 10x power than the other two, and is also more sensitive to PVT variation. Resolution of the leakage current monitor method is 10 MΩ (1.1%) with respect to its threshold 850 MΩ, and use 42.5aJ power in normal case. Sense amplification circuit can be modified to detect equivalent leakage resistance under 2KΩ.     

逆合成孔径雷达成像仿真

逆合成孔径雷达的运动补偿问题已有很多讨论,并在实际中得到成功的应用。运动补偿是ISAR成像技术的关键,分两步进行：包络对齐和相位校正。本文从全局效果出发,研究了平均包络最小熵包络对齐法和最小熵相位校准法的原理及算法实现,并对仿真数据进行成像处理。实验结果表明,平均包络最小熵法和最小熵相位校正法在ISAR雷达的运动补偿算...     

一种可重构带通复数滤波器及改进的无源补偿

本文介绍了一种用于多模多频全球卫星导航系统(GNSS)射频接收器的5阶、切比雪夫1型有源滤波器。其中,一种改进的无源补偿技术被用于消除积分器相位误差的影响,从而保证在不同条件下的频率响应带内平坦度。滤波器以6dB为步长,实现0～42dB增益调节范围,中心频率可在6.4MHz和16MHz两种模式间切换,带宽可在2MHz至20MHz间配置,频率校准精度在3%以内。电路使用0.18um CMOS工艺实现,在1.8V电源电压下工作,消耗电流7.8mA,片上面积为0.4mm^2.     

基于头部运动轨迹和3D视觉的跌倒检测系统

为了实现自动识别人体跌倒行为的目的,采用深度摄像头同时获取彩色图像和深度图像,并对其进行校正;对深度图像采用背景差分法提取运动人体前景;利用彩色图像和深度图像的融合、肤色检测以及距离加权面积法进行头部的检测与定位;最后将头部运动速度作为判断跌倒的依据,对人体不同运动行为的头部速度进行采集,利用支持向量机对跌倒进行检测。以5个志愿者的步行、蹲下、坐下和跌倒等4类动作为实验样本,运用交叉比对确定最优化参数,最后采用本文提出的方法进行测试。实验结果表明,系统能够有效识别跌倒,总体识别率超过95％。其中,跌倒／步行行为分类识别率达100％;针对跌倒／蹲下和跌倒／坐下的系统平均识别率分别为94．4％和98．8％。     

基于频域均衡的Tb/s级相干光单载波系统

对相干光单载波频域均衡系统(CO-SCFDE)、相干光单载波频分复用系统(CO-SCFDM)以及相干光正交频分复用系统(CO-OFDM)的理论和实验进行了对比研究,结果表明基于频域均衡的相干光单载波系统既保留了正交频分复用方式计算复杂度较低、频谱效率高和抗色散性能好的优点,又有效地减小了光纤非线性带来的传输损伤,是高速长距离光纤传输的一种有潜力的技术方案。     

A wideband LNA employing gate-inductive-peaking and noise-canceling techniques in 0.18μm CMOS

正This paper presents a wideband low noise amplifier(LNA) for multi-standard radio applications.The low noise characteristic is achieved by the noise-canceling technique while the bandwidth is enhanced by gateinductive -peaking technique.High-frequency noise performance is consequently improved by the flattened gain over the entire operating frequency band.Fabricated in 0.18μm CMOS process,the LNA achieves 2.5 GHz of -3 dB bandwidth and 16 dB of gain.The gain variation is within±0.8 dB from 300 MHz to 2.2 GHz.The measured noise figure(NF) and average HP3 are 3.4 dB and -2 dBm,respectively.The proposed LNA occupies 0.39 mm2 core chip area.Operating at 1.8 V,the LNA drains a current of 11.7 mA.     

非球面透镜组激光光束整形系统

在激光显示等领域常常需要光强均匀分布的激光光束,为此,深入分析了一种非球面透镜组激光光束整形系统的设计方法,该方法可以将入射光束为准直的单模高斯激光光束整形为光强均匀分布的准直平顶激光光束;给出了该非球面透镜组设计的基本过程,主要包括输出光束函数的选择、光线映射函数的确定和非球面参数的确定;最后选择光线映射函数具有解析解形式的匀化洛伦兹函数作为输出光束分布函数,分别确定了伽利略型和开普勒型的非球面透镜组激光光束整形系统的参数。     

SiGe BiCMOS工艺中HBT的关键制造工艺研究

研究了0.18μm SiGe BiCMOS中的核心器件SiGe HBT的关键制造工艺,包括集电极的形成、SiGe基区的淀积、发射极窗口的形成、发射极多晶的淀积、深孔刻蚀等,指出了这些制造工艺的难点和问题,提出了解决办法,并报导了解决相关难题的实验结果。     

低压配电台区线损异常及应对措施研究

电力在人们的生活和生产中都扮演着重要的角色,并且电力发展也成了当前人们研究的重要课题。在当前的电力部门中,低压配电建设仍然存在很多问题,这些都影响了我国电力企业的工作效率,影响了电力的正常使用。本文针对低压配电台区,分析其中出现的线损问题,并从计量装置异常问题入手,提出了有效的解决对策,希望能够实现对配电的有效利用,不断完善电力系统的使用效率。