Biodegradable Polyanhydrides as Encapsulation Layers for Transient Electronics

Bioresorbable electronic systems represent an emerging class of technology of interest due to their ability to dissolve, chemically degrade, disintegrate, and/or otherwise physically disappear harmlessly in biological environments, as the basis for temporary implants that avoid the need for secondary surgical extraction procedures. Polyanhydride‐based polymers can serve as hydrophobic encapsulation layers for such systems, as a subset of the broader field of transient electronics, where biodegradation eventually occurs by chain scission. Systematic experimental studies that involve immersion in phosphate‐buffered saline solution at various pH values and/or temperatures demonstrate that dissolution occurs through a surface erosion mechanism, with little swelling. The mechanical properties of this polymer are well suited for use in soft, flexible devices, where integration can occur through a mold‐based photopolymerization technique. Studies of the dependence of the polymer properties on monomer compositions and the rates of permeation on coating thicknesses reveal some of the underlying effects. Simple demonstrations illustrate the ability to sustain operation of underlying biodegradable electronic systems for durations between a few hours to a week during complete immersion in aqueous solutions that approximate physiological conditions. Systematic chemical, physical, and in vivo biological studies in animal models reveal no signs of toxicity or other adverse biological responses.     

Robust Design of Dual‐Phasic Carbon Cathode for Lithium–Oxygen Batteries

Given that the performance of a lithium–oxygen battery (LOB) is determined by the electrochemical reactions occurring on the cathode, the development of advanced cathode nanoarchitectures is of great importance for the realization of high‐energy‐density, reversible LOBs. Herein, a robust cathode design is proposed for LOBs based on a dual‐phasic carbon nanoarchitecture. The cathode is composed of an interwoven network of porous metal–organic framework (MOF) derived carbon (MOF‐C) and conductive carbon nanotubes (CNTs). The dual‐phasic nanoarchitecture incorporates the advantages of both components: MOF‐C provides a large surface area for the oxygen reactions and a large pore volume for Li₂O₂ storage, and CNTs provide facile pathways for electron and O₂ transport as well as additional void spaces for Li₂O₂ accommodation. It is demonstrated that the synergistic nanoarchitecturing of the dual‐phasic MOF‐C/CNT material results in promising electrochemical performance of LOBs, as evidenced by a high discharge capacity of ≈10 050 mAh g^?1 and a stable cycling performance over 75 cycles.     

Whisker Growth Behavior of Sn and Sn Alloy Lead-Free Finishes

Sn whisker growth behavior, over periods of time up to 10,080 h at room temperature, was examined for Sn and Sn-Cu, Sn-Ag, Sn-Bi, and Sn-Pb coatings electroplated on copper in 2 μm and 5 μm thicknesses to understand the effects of the alloying elements on whisker formation. Sn-Ag and Sn-Bi coatings were found to significantly suppress Sn whisker formation compared with the pure Sn coatings, whereas whisker growth was enhanced by Sn-Cu coatings. In addition, annealed Sn and Sn-Pb coatings were found to suppress Sn whisker formation, as is well known. Compared with the 2-μm-thick coatings, the 5-μm-thick coatings had high whisker resistance, except for the Sn-Cu coating. Whisker growth was correlated with coating crystal texture and its stability during storage, crystal grain microstructure, and the formation of intermetallic compounds at Sn grain boundaries and substrate–coating interfaces.     

“军事通信基础”PPT的创意与实现

在军事通信基础课件的设计和制作中,详细分析了课程标准、课程特点和授课内容,得出该课件的创意流程。以现代通信技术发展趋势的PPT创意与实现等内容为例,运用三维效果、自定义动画、结构图插入、设置放映方式和旁白录音等PPT设计要素,实现了递进式展示、动画讲解、对比重现、组合说明等创意效果。用简练、生动、新颖的方式展示繁琐、枯燥、复杂的授课内容,调动感官接受知识的兴奋点,以期达到良好的教学效果。     

复合环形腔被动相干合成技术重要特性研究

复合环形腔被动相干合成技术是提高激光功率并保持良好光束质量的有效手段。本课题组对该技术进行了理论和实验研究,其中主要研究分析了基于光纤激光阵列的复合环形腔被动相干合成技术的路数扩展特性、抗相位扰动特性、偏振选择特性、脉冲合成特性以及光束拼接技术。详细报道了相关研究结果并总结分析了该技术方案的发展趋势。     

Red AIE Luminogens with Tunable Organelle Specific Anchoring for Live Cell Dynamic Super Resolution Imaging

Lysosomes and mitochondria play an important role in maintaining cell homeostasis. Visualizing the long-term activities of lysosomes and mitochondria on the nanometer scale in live cells is essential for further understanding their functions but remains challenging due to the limitations of existing fluorescent probes, such as aggregation-caused quenching (ACQ) effect, limited signal-to-noise ratio from fluorescence “always on” in the process of targeting organelle and poor photobleaching resistance. Herein, two efficient red-emitting aggregation-induced emission (AIE) luminogens are reported, which showed “off-on” fluorescence characteristic and specific lysosomes as well as mitochondria targeting capability. Owing to their AIE characteristics, a Stokes’ shift larger than 100 nm, good biocompatibility, and excellent photostability, the AIE luminogens have been successfully utilized for high fidelity imaging of lysosomes and mitochondria. By virtue of these two probes, stimulated emission depletion (STED) images of dynamic lysosomal fusion and mitochondrial fission with a high resolution of 65.6 nm are obtained. Furthermore, the interactions between lysosomes and mitochondria in the process of mitophagy are recorded. This study also provides practical guidance for designing specific organelle targeting probes to support live cell dynamic super-resolution imaging.     

基于BiCMOS技术的高速数字/模拟转换器

基于BiCMOS技术,进行了高速数字/模拟转换器研究.以并行输入类型,电流工作模式的16位D/A转换器为载体,进行了电路设计、工艺制作和测试.在±5.0V工作电压下,测试得到转换速率≥30MSPS,建立时间为50ns,增益误差为±8%FSR,积分非线性误差为1/2 LSB,功耗为500mW.     

USB2.0技术在数据采集传输系统中的应用设计

介绍了一种高速实时数据采集处理系统中的USB2．0接口的硬件、固件设计方案以及其驱动的实现。该系统采用ADSP-2188M数字信号处理器和ISP1581 USB2．0设备接口芯片来实现系统与PC机之间的高速串行数据传输,提出了一种使用多芯片开发符合USB2．0规范的外设端通用数据传输模块的方法。     

Improvement of linewidth enhancement factor in 1.55-μmmultiple-quantum-well laser diodes

The improvement of the linewidth enhancement factor in complex-coupled laser diode (CC-LD), or loss-coupled, was confirmed by measuring the spontaneous emission spectra below threshold from the sidewall of laser diodes. In addition, the serial resistance of the device was measured. The linewidth enhancement factor is improved by the presence of a light absorbing InGaAs grating for loss coupled distributed-feedback (DFB) laser diode (LD). We report the comparison of the linewidth enhancement factors of Fabry-Perot (FP) LD, conventional DFB-LD, and loss coupled DFB-LDs     

基于遗传算法的水电站厂内经济运行新算法

本文提出求解水电站厂内经济运行问题的新方法－遗传算法,它不同于常规优化算法的特点在于,从多个初值点开始,沿多路径搜索实现全局或准全局最优,计算过程不需要存贮状态或决策变量的离散点,减少计算机内存,不必求导计算,编程简单,是一种有效的自适应随机搜索算法。