完整架构+量身定制 让大数据“价值最大化”

目前大数据技术发展得过于迅猛,导致了一个有趣的现象:我们一方面消费着由大数据技术支撑的各种服务(电商、社交网络、通信、医疗、交通等等),一方面又对这个新生事物存有各种疑惑,大数据到底是什么,会是一个新的商业噱头吗?塔吉特是美国第二大超市,它成功使用大数据技术实现了精准营销。为了提升孕妇相关产品的销售,顾客数据分析部建立了一个包含25种典型     

精密测试转台空气静压轴承动态特征

由于气体的可压缩性，惯导测试设备上的空气静压轴承，在工作中常发生气膜振荡而严重影响主轴刚度和运动精度。本文深入研究了在阶跃载荷及交变载荷作用下，轴承气膜的过渡特性及动刚度特性，为分析空气静压轴承的动态特性提供了理论根据，并成功地解决了转台轴承的稳定性问题。     

STRUCTURE AND PROPERTIES OF THE La-DOPED Bi-2201 SYSTEM

In this article, the influence of La substitution for Sr on structure and physi-cal properties of the 2201 phase is studied. First, the crystal microstructure of the Bi_2.1Sr_1.9-xLa_xCuO_y (0≤x≤1.0) is characterized by means of X-ray diffraction and electron diffraction analyses, it is discovered that in the La-doped 2201 system with increasing La content the 2201 phase undergoes tetragnoal-orthorhombic-monoclinic structural transition. With this phase transition, the modulation vector of the 2201 phase transforms from incommensurate to commensurate, and the period of the mod- ulation wave decreases. Secondly, the superconductivity of this system is analyzed systematically. The results of the resistivity measurement show that the appropriate amount of La doping can raise the superconducting transition temperature (T_c) of the 2201 phase, with x=0.2, T_c reaches as high as 25K. However the excessive doping of La (x≥0.3) leads the 2201 phase to transit from metal to insulator and the su-perconductivity disappears. The measurement of thermoelectric power (TEP) of this system shows that with increasing La content the TEP value also increases gradu-ally. But the interesting point is that the transition from positive to negative in TEP occurs for x=0.2 sample. In addition, the electronic structure and oxygen content of this system are also studied. Based on these, we analyze the relation between the microstructure, electronic structure of the La-doped 2201 phase and its superconduc-tivity, indicating that the type of element substitution with higher valence, together with the microstructural distortion induced by the substitution affects the electronic states of Cu 3d seriously, that is, changes the degree of coulomb correlation of Cu 3d electrons, thus resulting in the transition of the type of carrier of this system and the decrease of hole carrier concentration, as well as the corresponding variation of the superconductivity of La-doped 2201 phase.     

甲基蓝探针瑞利光散射测定奶制品中Cu(Ⅱ)

建立了检测奶制品中Cu(Ⅱ)的瑞利散射(RLS)法,探讨了适宜反应条件、反应机理、共存物质的影响及RLS光谱特征。在pH=5.50的Tris-HCl缓冲介质中,溴化十六烷基三甲基铵(CTMAB)增敏甲基蓝(MEB)使RLS信号显著增强,而Cu(Ⅱ)的加入则使体系的瑞利散射猝灭。在最大瑞利散射峰348nm处,Cu(Ⅱ)的质量浓度在0.007~0.13mg/L范围内与体系的RLS猝灭程度呈线性关系,检出限为0.0058mg/L,定量限为0.069mg/100g。方法用于奶制品中Cu(Ⅱ)的测定,加标回收率为98.4%~103%,相对标准偏差(RSD,n=6)为2.2%~2.8%。     

催化褪色光度法测定痕量钴

钴是人体健康不可缺少的微量元素，本文用酸碱指示剂间甲酚紫作为指示物质，催化动力学测定结果显示间甲酚紫在pH：10．0的NH3-NH4Cl缓冲溶液中呈紫色。Co(Ⅱ)对H2O2氧化这种紫色溶液褪色反应有催化作用，从而建立了测定钴的方法。该法可直接用于维生素B12和生物样品及地下水中Co(Ⅱ)含量的测定。     

分光光度法测定冻干粉针剂和滴眼液中甲磺酸帕珠沙星

在硝酸溶液中,铁(Ⅲ)与甲磺酸帕珠沙星在室温下形成橙黄色配合物,其最大吸收波长为470nm,采用分光光度法测定冻干粉针剂和滴眼液中甲磺酸帕珠沙星的含量。甲磺酸帕珠沙星的质量浓度在3.0～540.0mg·L~(-1)内与其对应的吸光度呈线性关系,检出限(3s/k)为0.88mg·L~(-1)。方法用于冻干粉针剂和滴眼液样品的分析,加标回收率为96.8%～101%,测定值的相对标准偏差(n=5)为1.3%～1.4%。     

基于深度学习的远程视频监控异常图像检测

针对复杂场景下远程视频监控图像异常检测困难、传统算法功能单一(仅针对某种特定场景或某种异常图像进行检测)等问题,提出一种基于深度学习的全自动远程视频异常图像检测方法。首先采用Xavier方法对自行设计的卷积神经网络(Convolutional Neural Network,CNN)的参数进行初始化,然后将标准化后的视频差分图送入CNN的输入层,通过特征提取及下采样,最后在CNN的输出层获得远程视频异常图像检测结果。实验结果表明,该方法可以对远程视频监控中突然出现遮挡、模糊和场景切换等多种异常同时进行实时在线检测,准确率可达88.75%。     

基于小型无人机飞行试验的数据采集器

研究了基于小型无人机飞行试验的数据采集器。利用单片机C8051F121全双工串口UART实时接收飞行试验数据,将数据保存在FLASH芯片K9K8G08U0A中;采用铁电存储器FM25CL64保存数据链表;设计数据提取软件,使用者可根据需要将存储在FLASH芯片K9K8G08U0A中的数据下载到上位机中进行分析和处理。该数据采集器体积约50mm×35mm,成本仅200元,容量为8Gbit,能存储30h的试验数据,保存数据约10年,使用方便可靠,完美实现了试验数据实时记录和按需提取,具有重要的工程应用价值。     

联合BSS和FRFT的雷达抗主瓣干扰新方法

有源压制干扰从雷达天线的主瓣进入雷达内部,干扰信号很强时,将严重影响雷达的检测性能。传统的旁瓣消隐、旁瓣相消以及低副瓣天线等技术难以奏效。文中分析了盲源分离技术应用雷达主瓣抗干扰时盲源分离的信号存在幅度、相位的不确定性,提出了一种联合盲源分离和分数阶傅里叶变换的雷达抗主瓣干扰的新方法。并给出新方法与传统脉冲压缩方法主瓣干扰抑制的仿真结果,仿真结果表明了在强噪声压制干扰环境中,新方法具有良好的抗主瓣干扰的性能。     

A high efficiency all-PMOS charge pump for 3D NAND flash memory

For 3D vertical NAND flash memory, the charge pump output load is much larger than that of the planar NAND, resulting in the performance degradation of the conventional Dickson charge pump. Therefore, a novel all PMOS charge pump with high voltage boosting efficiency, large driving capability and high power efficiency for 3D V-NAND has been proposed. In this circuit, the Pelliconi structure is used to enhance the driving capability, two auxiliary substrate bias PMOS transistors are added to mitigate the body effect, and the degradation of the output voltage and boost efficiency caused by the threshold voltage drop is eliminated by dynamic gate control structure. Simulated results show that the proposed charge pump circuit can achieve the maximum boost efficiency of 86% and power efficiency of 50%. The output voltage of the proposed 9 stages charge pump can exceed 2 V under 2 MHz clock frequency in 2X nm 3D V-NAND technology. Our results provide guidance for the peripheral circuit design of high density 3D V-NAND integration.