基于UV光照的圆片直接键合技术

研究了UV辅助活化与湿化学清洗活化相结合的圆片直接键合技术,并利用红外测试系统、单轴拉伸测试仪和场发射扫描电子显微镜,结合恒温恒湿实验、高低温循环实验对键合质量进行了测试.结果表明,采用该技术可以实现较好的圆片直接键合,提高键合强度,控制合适的UV光照时间可以获得更高的强度,对键合硅片进行恒温恒湿和高低温交变循环处理后,硅片仍能保持较高的键合强度.因此,该工艺对于改进圆片直接键合技术是行之有效的,具有很大的应用潜力.     

适用于低频率生理信号片上谱分析的低功耗数字芯片设计

本文针对人体传感网络的应用定制设计了一款基于片上处理技术的低功耗的数字芯片。该数字芯片主要包括一个用于生物医学信号谱分析的可扩展FFT处理模块,一个授权的ARM7TDMI内核和其他外围IP模块。该FFT采用了一种新的混合结构,存储器优化,减少乘法器,高效率的地址产生技术来降低功耗。芯片经过流片,并实际测试后表明,性能方面能满足生物医学信号处理要求,功耗方面,在1.8v输入下,功耗仅0.69mW @ 1MHz,该芯片计算256点FFT的能量是基于ARM7嵌入式平台计算所耗功耗的0.9%,同时,与业界主流ASIC实现的FFT相比,也具有低功耗优势。     

Numerical Solutions of the Integral Equation for Excitation-Transmission-Radiation of the Beam Waveguide

The numerical method of the Integral Equation has been used to model the electromagnetic excitation, transmission, and radiation problems of the beam waveguide. The Mode Matching Method has been used to describe the impedance matching situation at the exciting aperture of the waveguide. The excitation conditions were established based on the expansion of the waveguide modes and the continuity of the tangential components of the fields. The volume-surface integral equations combined with the equavalence principle have been used to model the wave transmission in the beam waveguide. The numerical solutions of the electromagnetic transmission and aperture radiation of the waveguide have been given by using the Multilevel Fast Multipole Algorithm (MLFMA). It has been demonstrated that the method proposed by this paper is able to provide the efficient and accurate numerical solution for the excitation, propagation and radiation problems of the beam waveguide with arbitrary shape and electrically large size.     

Size‐Transformable Metal–Organic Framework–Derived Nanocarbons for Localized Chemo‐Photothermal Bacterial Ablation and Wound Disinfection

Severe infectious diseases caused by pathogenic bacteria have become urgent threats to global public health. Antibacterial materials with combined chemo‐photothermal therapeutic capabilities possess distinct advantages when compared with many other antibacterial approaches. However, developing simplified and chemically tunable precursors to synthesize such antibacterial nanoagents for rapidly, safely, and synergistically combating pathogenic bacteria remains a huge challenge. Herein, metal–organic framework (MOF)‐derived nanocarbons with near‐infrared (NIR)‐responsive and size‐transformable capabilities are designed to overcome this challenge. The MOF‐derived nanocarbons with chemo‐photothermal bactericidal capabilities are first synthesized, and then coated with a thermoresponsive gel layer to obtain ON–OFF switching capability for bacterial trapping. The fabricated nanocarbons exhibit high photo‐to‐thermal conversion efficiency and fast size transformation from nanodispersions to micrometer aggregations upon NIR irradiation, thus enabling nanocarbons to generate localized massive heat and abundant Zn²⁺ ions for directly disrupting bacterial membrane and intracellular proteins. Furthermore, these nanocarbons not only exhibit a nearly 100% bactericidal ratio at very low dosage, but also possess highly efficient and safe wound disinfection activities, which are comparable to vancomycin. Overall, these proposed novel nanocarbons display robust and localized chemo‐photothermal bactericidal capability and possess great potential to be used as alternative to antibiotics for broad‐spectrum eradication of pathogenic bacteria.     

激光大坝位移实时监测系统研究

本文研究了激光大坝位移实时监测系统的原理,制作了焦距为１０ｍ的菲涅 波反,给出了在５０ｍ距离上的测量结果。     

脉冲激光二极管端面泵浦Nd;YAG棒时变温度场

在脉冲激光二极管(LD)泵浦的激光晶体中存在升降温的时变过程,为解决脉冲LD端面泵浦的激光晶体产生的热效应问题,基于热传导方程,采用特征函数法和常数变异法得到了脉冲超高斯光束端面泵浦Nd∶YAG棒的时变温度场的一般解析表达式.同时定量分析了单脉冲和重复脉冲端面泵浦Nd∶YAG棒的时变温度规律.研究结果表明,重复脉冲端面...     

Stability of Skutterudite Thermoelectric Materials

By multifilling with La, Ba, Ga, Ti, Yb, Ca, Al, and In, the dimensionless figure of merit ZT of filled skutterudites has been improved in this work. ZT reached 0.75 for p-type (La,Ba,Ga,Ti) _x (Fe,Co)₄Sb₁₂ (x = 0.8 to 1.0) and 1.0 for n-type (Yb,Ca,Al,Ga,In) _y (Co,Fe)₄Sb₁₂ (y = 0.7 to 0.9). After annealing at 873 K for 180 h, 300 h, 710 h, 1000 h, and 5000 h in vacuum, the Seebeck coefficient S and the electrical resistivity ρ of the samples increased while the thermal conductivity λ decreased with increasing annealing time. As a result, the ZT values of both p- and n-type skutterudites remained unchanged or were slightly improved, demonstrating the excellent thermal stability of these skutterudites.     

具有简单线性补偿和准谐振导通的原边控制的单级反激式LED驱动器

A single-stage flyback driving integrated circuit （IC） for light-emitting diodes （LEDs） is proposed. With an average primary-side current estimation and negative feedback networks, the driver operates in the boundary conduction mode （BCM）, while the output current can be derived and regulated precisely. By means of a simple external resistor divider, a compensation voltage is produced on the ISEN pin during the turn-on period of the primary MOSFET to improve the line regulation performance. On the other hand, since the delay time between the time that the secondary diode current reaches zero and the turn-on time of the MOSFET can be automatically adjusted, the MOSFET can always turn on at the valley voltage even if the inductance of the primary winding varies with the output power, resulting in quasi-resonant switching for different primary inductances. The driving IC is fabricated in a Dongbu HiTek＇s 0.35μm bipolar-CMOS-DMOS process. An 18 W LED driver is finally built and tested. Results show that the driver has an average efficiency larger than 86%, a power factor larger than 0.97, and works under the universal input voltage （85-265 V） with the LED current variation within ±0.5%.     

Washable Multilayer Triboelectric Air Filter for Efficient Particulate Matter PM2.5 Removal

Efficient removal of particulate matter (PM) is the major goal for various air cleaning technologies due to its huge impact on human health. Here, a washable high‐efficiency triboelectric air filter (TAF) that can be used multiple times is presented. The TAF consists of five layers of the polytetrafluoroethylene (PTFE) and nylon fabrics. Compared with traditional electrostatic precipitator, which requires a high‐voltage power supply, the TAF can be charged by simply rubbing the PTFE and nylon fabrics against each other. The electrical properties of the TAF are evaluated through the periodic contacting–separating of the PTFE and nylon fabrics using a linear motor, and an open‐circuit voltage of 190 V is achieved. After charging, the TAF has a removal efficiency of 84.7% for PM_0.5, 96.0% for PM_2.5, which are 3.22 and 1.39 times as large as the uncharged one. Most importantly, after washing several times, the removal efficiency of the TAF maintains almost the same, while the commercial face mask drops to 70% of its original efficiency. Furthermore, the removal efficiency of the PM_2.5 is very stable under high relative humidity. Therefore, the TAF is promising for fabricating a reusable and high‐efficiency face mask.     

一种在无线衰落信道上支持实时业务的分组调度算法

无线分组调度算法能为蜂窝网络中的移动用户提供服务质量的保证。在此问题上,以前的研究工作中一个经典的假设是基站与用户之间的信道条件变化为一平稳随机过程。但在实际情况中,这样的平稳假设并非总是合理的。研究表明基于平稳假设的调度算法,如流行的M-LWDF和EXP-rule算法,在非平稳信道上的性能下降明显。在CDMA蜂窝通信系统中,为在时变衰落信道上支持实时数据业务,该文提出一种基于模糊逻辑控制的分组调度算法,简称FROS。它能在保证用户QoS要求的同时,考虑到无线信道的快衰落特性而充分利用多用户分集(Multiuser diversity)所带来的增益,从而提高系统容量。系统级仿真证明,FROS算法能在优化系统分组时延性能和优化系统吞吐量性能之间保持良好的平衡和折衷,在平稳信道和非平稳信道的条件下都能获得比M-LWDF和EXP-rule算法更好的性能。