破碎复合型难采矿体安全高效采矿方法优化研究

根据太平铁矿地下涌水量大、矿岩松散软破的复合型难采现状,在"安全、经济、高效"的原则下,对矿山原有的上向水平分层充填采矿法的多个工艺环节进行优化设计,采用简单灵活的盘区上向进路式水平分层尾砂胶结充填采矿法,能根据矿体的具体分布形态有针对性地完成回采,使矿石回收率提高5%~10%;减小了空区暴露面积,有利于顶板维护和管理,极大地提高采矿作业的安全性;用生产效率更高的铲运机代替了落后的电耙出矿方式,使矿块生产能力提高了30~70t/d;同时,贫化率降低了6.31%,较好地发挥了矿产资源的经济效益、社会效益、环境效益。     

荧光免疫层析试条光电信号处理及特征量选取

荧光免疫层析定量检测技术是一种正在兴起的即时检验技术。在前期荧光免疫层析定量检测仪的研究基础上,采用小波算法对A/D采样后的荧光信号进行去噪处理,选用中值滤波剔除基线漂移,最后比较了采用测试线峰值和面积作为特征量的定量检测效果。数据显示,去噪后信噪比提高10 d B,相对均方差减小30.4%;采用峰值和面积值作为定量特征量的测量CV值分别为5.1%和0.4%,测量误差分别为9.1%和0.9%。结果表明采用积分面积作为特征量对荧光信号进行定量检测具有更好的准确度和重复性。     

Moving ion fronts in mixed ionic‐electronic conducting polymer films

The aim of this paper is to analyze moving front dynamics of ions and holes in a planar, mixed ionic‐electronic conducting polymer film. As cations invade the film, holes evacuate; thus, an ionic current is converted to an electronic signal. Recent experiments show that the location of the advancing ion front increases as the square‐root of time, a scaling typically associated with diffusive transport, which is surprising given the large driving voltages utilized. Ionic and electronic transport is modeled via the drift‐diffusion equations. A similarity transformation reduces the governing partial differential equations to ordinary differential equations that are solved numerically. The similarity transformation elucidates the origin of the square‐root‐of‐time front scaling. The similarity solution is then compared to the numerical solution of the full drift‐diffusion equations, finding excellent agreement. When compared with experimental data, our model captures the front location; however, qualitative differences between the ion profiles are observed. © 2015 American Institute of Chemical Engineers AIChE J, 61: 1447–1454, 2015     

基于内置光栅的大功率激光二极管

研制了一种用作光纤激光器泵浦光源内置光栅的976 nm激光二极管,分析了外延结构和芯片平面结构设计,并着重对内置光栅进行了理论分析和设计,通过技术研究和工艺优化,研制出了满足系统工程应用的激光二极管,其主要光电性能参数如下:中心波长为976±1 nm;光谱半宽小于等于1 nm;中心波长温度漂移系数小于等于0.1nm/℃;输出功率大于等于10W;发光条宽度小于等于100 μm.     

一种分段曲率补偿带隙基准源设计

在传统带隙基准的基础上,设计了一种分段曲率补偿的低温漂带隙基准。利用NMOS管工作在亚阈值区域时漏电流和栅极电压的指数特性,在低温和高温段同时对基准电压进行曲率补偿,采用UMC 0.25μm BCD工艺进行仿真。仿真结果表明,电源电压5 V时,静态功耗电流为7.11μA;电源电压2.5~5.5 V,基准电压变化148μV;温度在–40~+145℃内,电路的温度系数为1.18×10–6/℃;低频时电源抑制比为–87 d B。     

联合Kalman和自适应Meanshift的稳健相关视频跟踪方法

相关视频跟踪器存在计算量大、模板漂移、对机动目标,杂波影响大以及遮挡情况无法跟踪的问题,而Kalman滤波能通过利用相关跟踪器的输出结果来预测目标在下一帧里在图像中的坐标,可以在高概率的小范围内对目标进行搜索,以大幅减小计算量和杂波的影响.然后,当跟踪器由于受到杂波或遮挡的影响而提供了错误的测量信息时,跟踪的性能将大幅下降.大量研究表明,Mean-Shift跟踪器具有运算速度快和跟踪性能好的特点,而当目标柱状图和待选图像区域相近时,其跟踪性能也将大幅下降,甚至无法进行跟踪.为了解决该问题,结合上述3种思想提出了一种改进的、稳健的视频目标跟踪方法,并通过理论分析和仿真结果表明了算法的有效性和优越性.     

Modelling of nanostructured TiO2-based memristors

The fourth fundamental circuit element memristor completes the missing link between charge and magnetic flux. It consists of the function of the resistor as well as memory in nonlinear fashion. The property of the memristor depends on the magnitude and direction of applied potential. This unique property makes it the primitive building block for many applications such as resistive memories, soft computing, neuromorphic systems and chaotic circuits etc. In this paper we report TiO2-based nanostructured memristor modelling. The present memristor model is constructed in MATLAB environment with consideration of the linear drift model of memristor. The result obtained from the linear drift model is well matched with earlier reported results by other research groups.     

Si/SiC-based DD hetero-structure IMPATTs as MM-wave power-source: a generalized large-signal analysis

A full-scale, self-consistent, non-linear, large-signal model of double-drift hetero-structure IMPATT diode with general doping profile is derived. This newly developed model, for the first time, has been used to analyze the large-signal characteristics of hexagonal SiC-based double-drift IMPATT diode. Considering the fabrication feasibility, the authors have studied the large-signal characteristics of Si/SiC-based hetero-structure devices. Under small-voltage modulation (～ 2%, i.e. small-signal conditions) results are in good agreement with calculations done using a linearised small-signal model. The large-signal values of the diode's negative conductance (5 × 10⁶S/m²), susceptance (10.4 × 10⁷ S/m^2}), average breakdown voltage (207.6 V), and power generating efficiency (15%, RF power: 25.0 W at 94 GHz) are obtained as a function of oscillation amplitude (50% of DC breakdown voltage) for a fixed average current density. The large-signal calculations exhibit power and efficiency saturation for large-signal (> 50%) voltage modulation and thereafter decrease gradually with further increasing voltage-modulation. This generalized large-signal formulation is applicable for all types of IMPATT structures with distributed and narrow avalanche zones. The simulator is made more realistic by incorporating the space-charge effects, realistic field and temperature dependent material parameters in Si and SiC. The electric field snap-shots and the large-signal impedance and admittance of the diode with current excitation are expressed in closed loop form. This study will act as a guide for researchers to fabricate a high-power Si/SiC-based IMPATT for possible application in high-power MM-wave communication systems.     

离轴三反空间相机与卫星平台的优化连接方式

对于与卫星平台卧式安装的长焦距离轴三反空间相机,由于地面与在轨状态环境条件不同引起平台接口与相机产生温度差,导致相机视轴漂移影响成像质量。为解决此问题,提出了将柔性连接座、刚性连接座和可解锁连接座配合应用的优化连接方式,实现了相机与平台在轨状态3点静定柔性连接,并在运载阶段利用可解锁连接座提高相机基频。利用有限元方法对优化连接方式进行验证,平台接口温度降低15℃引起次镜角度变化为9.62(安装位置跨距1.2 m),满足光学设计要求;同时运载阶段相机在X、Y、Z三方向频率响应基频分别为120 Hz、120 Hz、110 Hz,与全刚性连接情况相比无明显降低。利用试验工装模拟平台进行温度变化替代试验,平台在温度提高15 ℃情况下,试验结果与仿真结果相符,且次镜转角实测值与仿真结果最大误差为9%。试验结果说明优化连接方式解决了卫星平台与相机在轨状态温度差引起的视轴漂移的问题,提高了相机的在轨环境适应性。     

网络入侵检测系统中的漂移检测

目前基于机器学习的入侵检测系统大都建立在入侵数据始终保持统计平稳的假设之上,无法应对攻击者有意改变数据特性或新型攻击方式的出现,而导致的检测率下降的状况.对于上述问题,即攻击漂移,提出了加权Rényi距离的检测方法.在KDD Cup99数据集上的实验证明,Rényi距离可以有效地增强检测效果;在检测到漂移后,通过重新训练模型可以使得对攻击的识别率显著提高.