A carbon-covered silicon material modified by phytic acid with 3D conductive network as anode for lithium-ion batteries

The requirement for silicon-based anode material is growing and has received attentions. Silicon is a promising anode material for lithium-ion batteries due to the high theoretical capacity. However, the high volumetric variability of silicon has led to severe chalking and rapid capacity degradation. To ameliorate these problems, a carbon-covered silicon material with a 3D conductive network structure was prepared employing glucose and phytic acid as carbon sources. When acted as the anode for Lithium-ion batteries, the prepared composite material delivered 1612 mAh/g in the first cycle and approximately 600 mAh/g at 0.1 A/g after 200 cycles. In addition, even at 5 A/g, a high capacity of 503 mAh/g was reached, and when recovered to 0.1 A/g, the capacity of 878 mAh/g was maintained.     

有机杂质对丁炔二醇氢化反应的影响

研究了有机杂质甲醛、甲醇以及其它低级醇对丁炔二醇催化氢化的影响 ;并根据实验数据计算出氢化反应的动力学参数 ,为放大实验及工业设计提供参考数据。     

The effect of steam treatment on MeO/Al2O3 model catalysts (Me = Ni,Co, Cu,Fe)

To study the influence of steam on the solid state reaction between MeO (Me = Ni, Co, Cu or Fe) and Al₂O3, MeO/-Al₂O₃ and MeO/-Al₂O₃ model catalysts were kept in either N₂/20% O₂ or N₂/O₂/30% H₂O at 500–1000°C. The samples were subsequently analyzed with RBS and FTIR. Surprisingly, nickel, cobalt and copper volatilized when MeO/-Al₂O₃ or MeAl₂U₄/-Al₂O₃ samples were annealed in the presence of 0.3 atm steam at 1000°C. Especially copper was found to volatilize very rapidly in the presence of steam, even at a temperature as low as 800°C. FTIR spectra of steam-treated NiO/-Al₂O₃ samples showed the incorporation of hydroxyl groups in the nickel oxide layer. This observation and an excellent agreement with thermochemical calculations support our conclusion that the volatile species are metal hydroxides. The solid state reaction of MeO with-Al₂O₃ was found to proceed at a much higher rate in the presence of 0.3 atm steam at 500–800°C, presumably as a result of an enhanced surface mobility of Me and Al ions along the grain boundaries and the surfaces of the internal pores of the-Al₂O₃ support, when steam is present.     

Damping of quasiparticles in a layered two-dimensional electron gas: Influence of electron-phonon and electron-electron interaction

Damping of the quasiparticles in a layered two-dimensional electron gas has been calculated including the electron-phonon and electron-electron interaction. The calculations performed atT=0 andT0 show that the non-Fermi behavior can appear as in the case of the electron-plasmon interaction, but it is also enhanced by the presence of the phonons.     

矿井煤仓三维计算机辅助设计

针对传统的矿井煤仓二维设计存在绘图复杂、抽象、易出错等问题,提出了一种矿井煤仓三维计算机辅助设计的方案;以恒源煤矿的-600煤仓和主井缓冲煤仓为例,详细介绍了煤仓三维计算机辅助设计及其动画演示的具体实现。该方案解决了复杂工程施工中设计者与施工人员的交流问题,为高质量、快速施工提供了基础保障。     

煤矿井下三维人员定位及信息管理系统的研究

介绍了井下三维人员定位系统的组成、工作原理、功能及关键技术。该系统采用射频识别技术、ZigBee技术及3D技术,可实时识别与跟踪井下人员动态,并通过计算机网络采集、传送数据;还可通过仿真矿井虚拟现实井下人员的考勤、分布状态及运动轨迹,可在事故发生后为矿井人员的抢救提供可靠的位置信息,提高抢险救灾的效率。     

基于多目视觉的变形钢板三维测量方法

提出了一种使用4个相机测量变形钢板三维形状的方法;在没有纹理的钢板上画一些点,使用4个相机同时拍摄钢板;利用边缘检测算法找出钢板的边缘,利用特征点提取算法提取出4个图像中钢板上的特征点,并找到4个图像上精确的特征点匹配关系,然后测量出这些特征点的三维点;最后,以这些三维点为种子点向外区域增长,从而得到钢板的三维形状;实验对变形钢板进行三维测量,得到了钢板的精确的三维形状,结果验证了该方法的有效性和可行性。     

多路信号采集系统设计

信号采集器是信号和和控制器之间的枢纽,采集信号的质量和采集速度与控制质量密切相关。然而,自然界中的信号各种各样,环境复杂,而且控制器对信号的要求亦各不相同,这些都使得信号采集一直以来都存在技术难点。本文基于C8051F020单片机设计了一款多路信号采集系统,与传统的数据采集器相比,C8051F020具有集成度高、逻辑实...     

Parameterized complexity of control problems in Maximin election

Elections are a central model in a variety of areas. This paper studies parameterized computational complexity of five control problems in the Maximin election. We obtain the following results: constructive control by adding candidates is W[2]-hard with respect to the parameter “number of added candidates”; both constructive and destructive control by adding/deleting voters are W[1]-hard with respect to the parameter “number of added/deleted voters”.     

Revisiting Zhang's 1D calibration algorithm

In recent years, the camera calibration using 1D patterns has been studied and improved by researchers all over the world. However, the progress in that area has been mainly in the sense of reducing the restrictions to the 1D pattern movement. On the other hand, the method's accuracy still demands improvements. In the present paper, the original technique proposed by Zhang is revisited and we demonstrate that the method's accuracy can be significantly improved, simply by analyzing and reformulating the problem. The numerical conditioning can be improved if a simple data normalization is performed. Furthermore, a non-linear solution based on the Partitioned Levenberg-Marquardt algorithm is proposed. That solution takes advantage of the problem's particular structure to reduce the computational complexity of the original method and to improve the accuracy. Tests using both synthetic and real images demonstrate that the calibration method using 1D patterns can be applied in practice, with accuracy comparable to other already traditional methods.