Binder-free graphene/carbon nanotube/silicon hybrid grid as freestanding anode for high capacity lithium ion batteries

Light-weight graphene/Si (G/Si) hybrid binder-free electrode is deemed a high energy density anode contender for lithium ion batteries (LIBs). However, paper-like G/Si electrodes tend to show an increased migration distance for Li⁺ through the fast interlayer channel with the increment of electrode size, in addition to an intrinsically slow diffusion kinetics; thereby encumbering their commercial realisation in high energy density and long life LIBs. To address these problems, herein, sandwich-structured graphene/carbon nanotube/silicon (G/CNT/Si, Si: 56 wt.%, ∼500 nm) hybrid grid is designed, cognizant of its uniform and shorter Li⁺ migration distance. Cyclic voltammograms indicate G/CNT/Si paper and grid anode to exhibit good electrochemical activity at both low and high temperatures. Noteworthy is that the Li⁺ diffusion coefficient ratio between G/CNT/Si grid and paper anodes are 1.82, 1.64, 1.43, 1.36 and 1.53 at a temperature of −5, 10, 25, 40 and 55 °C, respectively. The initial coulombic efficiencies of both paper and grid anode are as high as ∼82%. After 60 cycles at 420 mA g⁻¹, the charge capacity of G/CNT/Si grid is retained at 808 mA h g⁻¹, which by far surpasses that of paper anode (i.e., 490 mA h g⁻¹). The attained lithium ion storage performance at both high and low temperatures, underpins the G/CNT/Si sandwiched grid as effective to realise the practical deployment of paper-like graphene electrodes for high energy density and long life LIBs.     

基于Windows Mobile的切削用量计算软件的开发

为了实现数控加工中切削用量的便捷计算,开发基于Windows Mobile的切削用量计算软件.该软件采用触摸按钮完成切削参数的输入,且具有输入数据的自动校验功能,实现了切削用量的便捷计算.经测试,该软件在多普达TOUCH HD型号或其他Windows Mobile操作系统的智能手机上均能正常运行,表明其具有良好的通用性.     

In Situ Synthesis of Reduced Graphene Oxide and Gold Nanocomposites for Nanoelectronics and Biosensing

In this study, an in situ chemical synthesis approach has been developed to prepare graphene–Au nanocomposites from chemically reduced graphene oxide (rGO) in aqueous media. UV–Vis absorption, atomic force microscopy, scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy were used to demonstrate the successful attachment of Au nanoparticles to graphene sheets. Configured as field-effect transistors (FETs), the as-synthesized single-layered rGO-Au nanocomposites exhibit higher hole mobility and conductance when compared to the rGO sheets, promising its applications in nanoelectronics. Furthermore, we demonstrate that the rGO-Au FETs are able to label-freely detect DNA hybridization with high sensitivity, indicating its potentials in nanoelectronic biosensing.     

LED灯绳自动装配设备的研究设计

设计了一款LED灯绳自动装配新型设备,设备采用单片机自动控制运行,它由放线机构、导线牵引进给机构、装配主机及自动控制系统等构成。介绍了LED灯绳的装配方法,重点介绍了导线牵引进给机构、装配主机结构中的灯卡自动扣紧机构和LED灯体自动送料机构,以及装配设备各机构间的动作协调关系。     

锂离子电池磷酸铁锂正极材料的制备及改性研究进展

橄榄石型磷酸铁锂(LiFePO4)由于安全性能好、循环寿命长、原材料来源广泛、无环境污染等优点被公认为是最具发展潜力的锂离子动力与储能电池正极材料。综述了近年来磷酸铁锂正极材料在制备和改性方面的最新进展。在此基础上,提出了磷酸铁锂正极材料未来的主要研究和发展方向。     

野生动物图像识别的重要价值及相关的法律应用

图像识别是野生动物形态鉴定中最常用的一种技术方法。此项技术检验速度快、鉴定成本低、对检材无损害,但动物特征点的判断和拍摄质量是检验鉴定的关键,不可忽视,否则,在法庭审判中会导致错判,损害公民的合法利益,甚至造成国家赔偿。     

共享学习模式下知识服务云平台的构建研究

通过剖析知识服务的内涵和特征,梳理知识服务中存在的问题,结合云计算的特性,给出共享学习模式下知识服务的新模式。构建了知识服务云平台体系结构,设计了知识资源层、知识融合层、知识服务层、运营服务与计费保障体系、客户应用层5个知识服务功能模块,实现了知识资源的共享和协同。     

无线多点DDC EDID信息共享的方法

为解决KVM设备中各种分辨率图像在显示屏上的实时正常显示,设计了一种以FPGA和nRF905构成的DDC主从端子组网的方法,实现EDID信息无线多点共享,阐述了各主从端子间的无线数据传输协议、多点接入方法与多点接入时的冲突解决.经实验检验能完整可靠地实现EDID信息共享.     

TD-SCDMA与WCDMA网络优化及切换方式比较

TD—SCDMA采用接力切换方式,WCDMA采用软切换方式,这是两种3G制式在移动性管理上的主要差异。但是在现场测试中可以发现设计切换的信令流程有着许多相似之处,但是两者在切换控制思想上有着很大的不同。同时在优化过程中也有着一定区别,网络优化是保证网络业务质量、充分利用网络资源的重要手段。对网络进行不断的优化,不仅是为了提高用户满意度,更可节约运营商的建设维护成本,提高其市场竞争力。     

认知无线电系统捷变频信号源设计

根据信道环境自适应调节数据速率的需求,设计了一款高性能的认知无线电系统信号源。该信号源以直接数字频率合成芯片AD9854（DDS）为核心,现场可编程门阵列（FPGA）芯片EP1C6Q240作为控制单元,实现频率捷变和调制速率捷变以及具有双路正交输出的功能。经测试,频率精度、稳定度及杂散抑制均达到设计要求,并可集成于认知无线电通信设备中。