介电泳芯片的研制及不同细胞介电分离的应用

制备了包括指状交叉、城墙状和梯形的微电极阵列芯片装置.并用这些芯片探索了生物细胞的介电响应.另外观察了酵母和鸡血红细胞的迁移、旋转和融合以及几种细胞收集图片.发现了两种细胞的正、负介电泳现象,确定了这两种细胞的分离条件.讨论了两种细胞正、负介电泳的原因.利用同一芯片在相同的条件下一种细胞移向强场区(正介电泳),另一种细胞移向弱场区(负介电泳).因此可用同一芯片分离不同的细胞.有望建立一种非接触式细胞分离技术,而且在分离过程中不需要添加任何试剂.     

Computer-Aided Design and Test for Digital Microfluidics

This article discusses several aspects of design and test methodology centered on digital microfluidics, including modeling, simulation, synthesis, test, and reconfiguration. The automated design methods for digital electronics and adaption of them to droplet-based microfluidics are explained. The test methodology detects both catastrophic and parametric faults by electrically controlling and tracking the motion of the test stimuli droplets and also facilitates concurrent testing, in which fault testing and biomedical assays run simultaneously on a microfluidic system.     

绝缘体介电电泳细胞分离器件数值分析和优化

绝缘体介电电泳(iDEP)利用微流体管道中均匀绝缘柱阵列产生介电电泳(DEP)所需要的非均匀电场,实现微全分析系统(μTAS)和芯片实验室(LOC)中细胞等生物粒子的分离.对这种新型的iDEP器件进行理论分析,建立了数值计算方法.基于有限元数值计算理论,利用Ansys软件,计算了细胞的介电电泳力,验证了iDEP的富集原理,对iDEP器件的介质形状、尺寸、间距和微管道长度等参数进行了优化,提出了设计准则.选用间距10 μm,圆形,微管道长度3550 μm的5×5绝缘柱阵列,器件性能最优.     

Meniscus-Assisted High-Efficiency Magnetic Collection and Separation for EWOD Droplet Microfluidics

This paper describes a technique to increase the efficiency of magnetic concentration on an electrowetting-on-dielectric (EWOD)-based droplet (digital) microfluidic platform operated in air, i.e., on dry surface. Key differences in the force scenario for droplet microfluidics vis-a-vis the conventional continuous microfluidic systems are identified to explain the rationale behind the proposed idea. In particular, the weakness of the magnetic force relative to the bead-substrate adhesion and the liquid-air interfacial tension is highlighted, and a new technique to achieve high-efficiency magnetic collection with the assistance of the interfacial force is proposed. An improvement in collection efficiency (e.g., from ~ 73% to ~ 99%) is observed with the new technique of ldquomeniscus-assisted magnetic bead collectionrdquo. In addition, isolation of the magnetic species from a mixed sample of magnetic and nonmagnetic beads is demonstrated. Comparison with other related reports is also presented.     

Polymer Microfabrication for Microarrays, Microreactors and Microfluidics

Polymer microfabrication methods are becoming increasingly important as low-cost alternatives to the silicon or glass-based MEMS technologies. Polymer hot embossing and injection molding are replication methods applicable to microreplication of a diversity of materials and microstructures.

Equipment with high precision control of pressure and temperature for hot embossing of polymer materials is now available commercially. These systems have made possible the replication of chips containing microchannels for capillary electrophoresis (CE) and microfluidics devices, microoptical components and microreactors. Stable and reproducible polymer microstructures have been demonstrated in several types of materials with structural and optical properties meeting other biocompatibility and detection requirements. The process involves few variable parameters and results in high structural accuracy suited for a wide range of microfabrication applications.

After demonstrating equivalent and, in cases, improved performance, the alternative use of plastic as the microdevice material addresses needs for rapid prototyping in product development and provides cost advantages in product commercialization. Thus an increasing number of devices have been reported recently in the literature, fabricated on a variety of polymer substrates and using different fabrication methods such as laser ablation, injection molding, silicone rubber casting or embossing for microfabrication.     

Acoustically Driven Programmable Microfluidics for Biological and Chemical Applications

In summary, we described a novel and unconventional technique to manipulate smallest amounts of liquid on a chip. Using SAW on a piezoelectric substrate, we are able to actuate individual droplets along predetermined trajectories, or induce acoustically driven internal streaming in the fluid. This internal acoustic streaming can efficiently be used to agitate, mix, and stir very small liquid volumes, where the low Reynold's number usually only allows for diffusive mixing. We described several applications of the SAW driven microfluidics, including a nanomixer for microarray applications, a contactless mixer for MTPs, a programmable microfluidic chip for droplet-based assays, and finally a chip performing high resolution microliter PCR. The technique is equally well suited to actuate or agitate small amounts of liquids either in closed volumes or in an open, droplet-based geometry. Each of the approaches has its clear advantages, but also disadvantages. Droplet-based fluidics is certainly well suited to handle smallest amounts of fluids without the risk of cross contamination etc. High temperature processes, however, require additional means like covering the droplet with an oil film. SAW pumping, mixing, and stirring on closed volumes is advantageous over many other pumping schemes as the pumps are easily incorporated into most of the existing microfluidic device or lab-on-a-chip. The combination of the SAW actuated droplet-based fluid handling and SAW driven fluidics in closed volumes opens a wide field of many different applications, a few of which I had the pleasure to present in this article. Many more applications, and many more visualizations of the technology described above can be looked up on Advalytix' website http://www.Advalytix.de.     

中速数字(IDR)通信

本文介绍了目前卫星通信网络中主要通信方式之一——中速数字(IDR)通信技术。着重介绍了各次群的复接方式,简单地介绍了数字倍增及多址技术。     

数字视频广播（DVB）

文章主要介绍数字视频广播(DVB)标准;数字视、音频特点;数据组成格式;MPEG-2码流复用方式;以及各种传输方式(包括:DVB-S、DVB-C、DVB-T)和传输电路的组成。     

A Programmable Biochip for the Applications of Trapping and Adaptive Multisorting Using Dielectrophoresis Array

The adaptive biochip integrating dielectrophoresis (DEP) traps and a programmable multisorting DEP array for the multisorting applications of biomolecules such as proteins and DNA is proposed and demonstrated in this paper. In this research, movable beads are used as the mobile probes to capture the target protein molecules. These beads are chemically modified and immobilized with p50 proteins in our demonstration. An array of micropyramid DEP traps with a good levitation control on the height of the beads is located at the upstream to enhance the hybridization function of the mobile probes. The sample solution mixed with Cy3-I-kappa-B-alpha complex is used in the demonstration. A programmable multisorting DEP array that is located at the downstream sorts out the hybridized beads, which are fluorescently labeled based on the fluorescent detection signals. The magnitude and direction of the DEP force that is applied to the beads with/without labeling fluorescence in the multisorting DEP array are controlled via the distribution of time-variant nonuniform electric fields. The voltage on the individual electrode of the multisorting DEP array is preprogrammed and controlled by a LabVIEW controller with fluorescence detection feedback signals. In contrast to the research of Manaresi et al. [IEEE J. Solid-State Circuits, vol. 38, no. 12, p. 2297, 2003], which was proposed for trapping and sorting beads and cells via Dent traps, to our knowledge, the design of this biochip with the hybridization enhancement via micropyramid DEP traps and the adaptive multisorting DEP array for the mobile probes has never been proposed and implemented to date.     

透视数字化关键技术(二)

数字化音／视频处理技术数字视频处理技术可以大大提高传输和存储性能、图像的清晰度和质量以及交互功能，这些都是模拟视频无法做到的。因此目前模拟视频正逐步被数字视频所取代，而发展最为迅速的两大视频产品是亚洲的ＶＣＤ和美国的ＤＳＳ（数字卫星系统）。数字视频技...     

基于数码相机的图象数字变焦（视图插补）算法

相邻象素之间的相关是图象数字变焦（视频插补）、图象平滑及滤波处理的理论基础。为此以图象的相关系数为量化参数，讨论了象素空间和灰度相关性；定义了象素的空间距离和灰度距离，并在此基础上构造了基于空间相关和灰度相关领域变焦（插值）算子，给出了该算子的离散算法、软件实现和仿真。仿真结果表明：该算法最大限度地减小了图象的几何失真和色彩失真，可满足数码相机数字变焦的视觉要求。本算法已应用于i.Photo系列数码相机。     

基于DDS技术的多种数字调制的实现

直接数字合成技术（DDS）随着专用芯片的大量出现而得到广泛的应用。现代数字通信所用的信号调制，也由于DDS技术的出现而变得简单了。中通过对DDS工作原理的分析，结合具体的DDS芯片和单片机控制技术，详细介绍了包括MFSK、QPSK及QAM调制技术在内的多种调制方法的具体实现。     

Separation axioms in (semi)topological quotient BL-algebras

In this paper, we study the relationship between separation axioms and (semi)topological quotient BL-algebras. We bring some conditions under which a (semi)topological quotient BL-algebra becomes a T ₁-space or Hausdorff or regular or normal. Also, we use maximum condition to get a Hausdorff or regular or normal (semi)topological quotien BL-algebra.     

数码相机发展及市场格局

数码相机作为一种图像输入设备,在以图像为主要信息载体的互联网时代,具有广阔的应用前景。论文介绍了数码相机关键技术及发展水平,分析了目前数码相机的市场格局及前景,讨论了我国数码相机企业面临的技术差距,探讨了我国数码相机产业化的发展模式,提出了“硬件集成,软件开发”的发展思路。     

混合选别浓密机底流矿浆浓度和流量区间智能切换mm控制方法

赤铁矿磁选-浓密-浮选过程中浓密机的底流矿浆浓度受到大而频繁的浮选过程产生的中矿矿浆随机干扰的影响,造成底流矿浆流量频繁波动在工艺规定的范围之外,使得矿浆在浮选机中选别时间缩短,液位波动造成有用金属流失,从而减少精矿品位和金属回收率. 本文分析了难以采用现有的底流矿浆浓度闭环控制策略的原因,提出了由流量设定和跟踪流量设定值控制组成的矿浆浓度与流量区间双闭环控制;提出了基于静态模型的流量预设定、模糊推理的流量设定补偿、流量设定保持器和规则推理的切换机制组成的流量设定智能切换控制方法. 与矿浆浓度闭环控制方法的仿真对比实验和在国内某大型赤铁矿混合选别浓密机的成功应用,表明所提出的方法在浮选中矿干扰下,不仅将底流矿浆浓度和流量控制在目标值范围内,而且明显减少底流矿浆流量波动,从而在保证金属回收率不变的条件下,显著提高了精矿品位.     

空分压缩机组安全完整性技术等级(SIL)技术评估应用及分析

依据相关IEC和API标准,对空分装置三大机组(蒸汽透平、空压机和增压机)的安全联锁系统(SIS)做了安全完整性等级(SIL)技术评估,确定了空分三大机组安全联锁系统中的安全联锁功能(SIF),给出了各安全联锁功能(SIF)所需达到的安全完整性等级(SIL),提出并分析了空分三大机组安全联锁系统中存在的多个典型问题,最后针对问题分别给出了相应的改进建议。研究结果对空分装置三大机组和类似机组的安全、稳定、长周期运行有借鉴意义。     

数字智能阀门定位器及其应用

以艾默生过程管理的Fisher DVC5000f系列数字智能阀门定位器为例，介绍了数字智能定位器的结构、性能特点、工作方式及其应用。     

基于线性预测的自适应递归最小二乘盲源分离

为了分离具有时序结构的信号,将线性预测均方误差作为代价函数.使分离出信号的可预测性最大,这样就可以分离出源信号.这种最小均方误差型算法,其在线形式采用瞬时预测误差代替预测误差的期望值.导致收敛速度较慢.为了提高这类算法的收敛速度,本文将线性预测误差的加权平均作为代价函数,提出了递归最小二乘型线性预测盲源分离算法.计算机仿真和实际语音分离试验均表明:提出的算法与最小均方误差型线性预测盲源分离算法相比具有更快的收敛速度,且增加的计算量不大.     

软件工程(数字媒体技术)特色专业的特色建设

根据教育部对对第二类特色专业建设点的建设目标及要求,针对软件工程(数字媒体技术)特色专业的办学定位和人才培养需求,提出用数字皮影打造软件工程(数字媒体技术)特色专业特色的建设方案,并以此为基础,开展特色专业建设,包括:课程建设、实验环境建设、科研教学团队建设以及学生科技活动平台建设。与此同时,对建设成果进行凝练和总结,使其能够被借鉴和推广。