用于识别人类白血病白细胞的 生物传感器的研究

本文介绍了一种以平面热解石墨电极为工作电极,用于识别健康人白细胞及白血病病人白细胞的半微分伏安型生物传感器.工作时,使抽滤在微孔滤膜上的白细胞与平面热解石墨电极紧密接触,然后于磷酸缓冲生理盐水中进行半微分循环伏安扫描.以同一扫描速率下的氧化峰电位(E_P),不同扫描速率下氧化峰电位的差值(△E_P),滤膜上单位细胞数的氧化电流的半微分值(e_p/cells),以及还原扫描有无还原峰等作为该生物传感器系统识别正常与异常白细胞的重要指标.     

多孔阳极氧化铝的化学修饰及其应用于过氧化氢的测定

多孔阳极氧化铝经化学修饰后吸附细胞色素C,制备了过氧化氢生物传感器电极。多孔阳极氧化铝通过电化学和化学腐蚀阻挡层后,用两步无电沉积方法制备了纳米金修饰的多孔阳极氧化铝电极,再在含有L-半胱氨酸的细胞色素C的溶液中通过吸附制备细胞色素C电极。用循环伏安法和计时电流法测试细胞色素C电极的电化学性能及催化对过氧化氢的还原。结果表明,包覆的细胞色素C电极显示较好的稳定性,在扫描速度为80 mV/s时于-50 mV、-190 mV附近出现一对稳定的氧化还原峰。该电极对过氧化氢具有良好的电催化还原性能,在1.5×10-5 mol/L～4.8×10-4 mol/L浓度范围内,电流与浓度呈良好的线性关系。多孔阳极氧化铝经化学修饰后,可应用于生物传感器。     

纳米Au修饰电化学传感器直接检测液相中沙林的研究

采用电势阶跃法,在Au电极表面修饰纳米Au,制备出的电化学传感器采用循环伏安法直接检测液相中的沙林,探讨了检测沙林的电化学反应机理.研究发现,检测沙林中,在1.4～0.1 V范围循环伏安扫描之前,预先进行2.0～-2.0V循环伏安扫描,是实现电化学方法检测沙林的重要先决条件.实验表明,纳米Au修饰Au电极表面后,提高了...     

基于微纳泡沫金属材料的D-半乳糖传感器研究

研究了一种基于微纳泡沫镍材料的D-半乳糖定量传感器,采用泡沫镍材料作为工作电极,Pt作对电极,Ag/AgCl（饱和KCl溶液）电极作为参比电极构建三电极检测体系,采用循环伏安法（CV）和电流-时间曲线法（i-t）检测具有浓度梯度的D-半乳糖溶液。CV扫描结果表明了D-半乳糖在泡沫镍材料上发生氧化-还原反应,i-t检测结果表明在线性范围0.25 mmol/L~5.00 mmol/L内该传感器检测D-半乳糖的灵敏度为6.73×10-2 mA/（cm2·（mmol/L））,检测限为17.7μmol/L（S/N=3）。结果证明所构建的检测方法不但可以实现D-半乳糖的定量分析,并且具有较好的灵敏度和较低的检测限。对比实验结果表明该传感器具有响应速度快、成本低廉等优势,有望在糖类物质快速定量检测领域得到应用。     

谷胱甘肽,溶菌酶和胸腺肽在微电极上的电化学响应

本文用线性扫描伏安法研究了谷胱甘肽、溶菌酶和胸腺肽在不同反应体系中的伏安特性。通过它们在不同缓冲体系中和不同微电极上的电化学响应，发现谷胱甘肽在酸性ＮａＡｃ－ＨＡｃ体系中金丝镀汞电极上有最大响应，同时，发现铜也是一种可资应用电极材料。溶菌酶的最佳响应是在ＮａＯＨ体系中的铜电极上产生的。在ＮａＡｃ－ＨＡｃ体系中，胸腺肽在金电极上有最佳响应，在铜电极上响应也很灵敏。     

基于三维多孔泡沫镍材料的乳糖传感器研究

提出了一种基于三维多孔泡沫镍的乳糖传感器,采用泡沫镍材料作为工作电极,铂电极作为对电极,在0.1 M的NaOH碱性环境中以循环伏安法(CV)和电流-时间曲线法(i-t)建立了乳糖定量检测方法,循环伏安扫描结果证明乳糖可以被泡沫镍氧化,电流-时间检测结果表明乳糖在0.2 mmol/L~3.5 mmol/L的线性浓度范围内,泡沫镍检测乳糖的灵敏度为9.433 1 mA/(cm2·mmol/L),检测限为6.8μmol/L.本文所研究的乳糖传感器具有响应速度快、成本低、高灵敏度、低检测限等优势,具有较好的实际应用价值.     

碳纳米管/聚苯乙烯-共-N-聚异丙基丙烯酰胺纳米粒子修饰电极的过氧化氢传感器

该工作制备了碳纳米管/聚苯乙烯-共-N-聚异丙基丙烯酰胺纳米粒子(CNTs/PS-coNIPAm),利用其修饰玻碳电极(GCE)发展了高灵敏的过氧化氢(H₂O₂)电化学传感器。通过扫描电子显微镜(SEM)和循环伏安曲线(CV)对制备的修饰材料进行了表征。结果显示,CNTs/PS-coNIPAm修饰电极具有较大的比表面积和优异的电催化活性。与裸电极相比,修饰后的GCE电极对H₂O₂显示出明显提高的电流信号。CNTs/PS-co-NIPAm为发展新型电化学传感器提供了一条有前景的电极材料。     

葡萄糖生物传感器检测重金属离子的研究

本文采用葡萄糖氧化酶生物传感器,利用重金属对葡萄糖氧化酶的抑制作用,来检测环境中微量的Cu2 和Hg2 浓度.以普鲁士蓝修饰的葡萄糖氧化酶电极为工作电极,饱和甘汞电极为参比电极,自制铂片电极为对电极,在三电极体系中,用循环伏安法进行扫描.考察了缓冲溶液pH值、温度等因素对葡萄糖氧化酶生物传感器检测Cu2 、Hg2 的影响.在较宽的浓度范围内,峰值电流与酶抑制剂浓度的对数呈良好的线性关系.检测Cu2 和Hg2 时,传感器的线性响应范围分别为5～40μmol/1和2.5～22.5μ.mol/1,最佳响应条件选择pH值为6.86,温度为25℃.上述酶传感器可用于毒性评价和环境监测等领域.     

复合式氧化还原指示电极的研制

本文研制出一种结构简单、制作方便、性能稳定的复合式ＯＲＰ电极，该电极由Ｐｔ丝工作电极、固态Ａｇ－ＡｇＣｌ参比电极组成，这种复合ＯＲＰ电极使用方便，可用作一般科研、工业生产的指示电极。     

基于TB/Nafion膜的pH传感器

电流型pH传感器的研究开始受到了人们的关注,该实验研制了一种基于TB/Nafion膜的新型电型pH传感器。用该传感器对不同pH的磷酸缓冲溶液进行循环伏安分析测试,结果表明TB/Nafion膜修的电极在不同pH的测试底液中的循环伏安曲线的氧化峰和还原峰电位均与pH呈线性关系,该修饰电可用于弱酸性溶液pH的测定。通过对电极修饰过程及pH测定方法的学习及分析,可进一步提高学生pH传感器和循环伏安法的掌握,为本科仪器分析实验提供了新颖的尝试。     

A fast method for choosing the optimum extrapolation parameter for an e.a.d.i. scheme

This paper describes a fast method for choosing the optimum extrapolation parameter ω in an Extrapolated Alternating Direction Implicit (E.A.D.I.) Scheme, for the numerical solution of elliptic partial differential equations. An analysis is presented to show that in the case that the acceleration parameter r is varied, a set of values for the extrapolation parameter ω could be defined. The optimum value of ω is easily obtained from this set. A numerical example demonstrates the applicability of the proposed method.     

基于CompactLogix和现场总线的过程控制系统

对过程控制中的集散控制系统DCS与现场总线控制系统FCS进行了比较,详细阐述了基于Rockwell Automation的现场总线技术DeviceNet的网络控制方法,并通过PID算法编程与监控软件开发,实现了基于CompactLogix控制器与DeviceNet现场总线的过程控制系统。     

COMPUTER-MOVIE的设计与实现技术

COMPUTER MOVIE是一个适用于PC系列微机的计算机教学动画演示系统,可应用于计算机原理、计算机系统结构、微型计算机等课程的教学。本文论述了该系统的构成以及在该系统中采用的一系列作图技术,包括:实现结构化图形实体移动的方法、“面向图形实体/事件驱动/自然遮挡”动画作图法、菜单、背景色调整、相对坐标和大小的采用、多条同时动态延伸线的画法等。这些技术适用于各种教学动画软件的设计与实现。     

基于嵌入式系统的网络化自动抄表系统

设计基于嵌入式系统的网络化自动抄表系统,并着重阐述系统的硬件、软件构成和设计特点。该系统可用于建筑中电、水、气、热等仪表数据的采集和住户耗能设备的控制。自动抄表有利于能量管理部门实现能源的监控管理,提高能源使用效益,对于中国的可持续发展具有非常重要的意义。     

离散系统的一种从模型取状态鲁棒MRAC方案

本文对具有可测扰动的离散系统提出了一种从模型取状态的鲁棒模型参考自适应控制ＭＲＡＣ（模型参考自适应控制）新算法。     

Circular Separability of Polygons

Two planar sets are circularly separable if there exists a circle enclosing one of the sets and whose open interior disk does not intersect the other set. This paper studies two problems related to circular separability. A linear-time algorithm is proposed to decide if two polygons are circularly separable. The algorithm outputs the smallest separating circle. The second problem asks for the largest circle included in a preprocessed, convex polygon, under some point and/ or line constraints. The resulting circle must contain the query points and it must lie in the halfplanes delimited by the query lines. Received October 25, 1998; revised April 21, 1999.     

利用Remoting技术实现分布式系统的开发

运用.NET Remoting进行分布式应用程序开发不仅提高开发效率,而且具有开发的简单性和系统的灵活性,特别是在局域网内运用TCP进行数据传输可以提高数据传输效率.本文介绍了.NET Remoting的体系结构,提出基于.NET Remoting的分布式应用程序的开发方法,并详细论述了在Visual Studio .NET中实现该方法的过程.     

KANTBP: A program for computing energy levels, reaction matrix and radial wave functions in the coupled-channel hyperspherical adiabatic approach

A FORTRAN 77 program is presented which calculates energy values, reaction matrix and corresponding radial wave functions in a coupled-channel approximation of the hyperspherical adiabatic approach. In this approach, a multi-dimensional Schrödinger equation is reduced to a system of the coupled second-order ordinary differential equations on the finite interval with homogeneous boundary conditions of the third type. The resulting system of radial equations which contains the potential matrix elements and first-derivative coupling terms is solved using high-order accuracy approximations of the finite-element method. As a test desk, the program is applied to the calculation of the energy values and reaction matrix for an exactly solvable 2D-model of three identical particles on a line with pair zero-range potentials.

Program summary

Program title: KANTBPCatalogue identifier: ADZH_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADZH_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 4224No. of bytes in distributed program, including test data, etc.: 31 232Distribution format: tar.gzProgramming language: FORTRAN 77Computer: Intel Xeon EM64T, Alpha 21264A, AMD Athlon MP, Pentium IV Xeon, Opteron 248, Intel Pentium IVOperating system: OC Linux, Unix AIX 5.3, SunOS 5.8, Solaris, Windows XPRAM: depends on (a) the number of differential equations; (b) the number and order of finite-elements; (c) the number of hyperradial points; and (d) the number of eigensolutions required. Test run requires 30 MBClassification: 2.1, 2.4External routines: GAULEG and GAUSSJ [W.H. Press, B.F. Flanery, S.A. Teukolsky, W.T. Vetterley, Numerical Recipes: The Art of Scientific Computing, Cambridge University Press, Cambridge, 1986]Nature of problem: In the hyperspherical adiabatic approach [J. Macek, J. Phys. B 1 (1968) 831-843; U. Fano, Rep. Progr. Phys. 46 (1983) 97-165; C.D. Lin, Adv. Atom. Mol. Phys. 22 (1986) 77-142], a multi-dimensional Schrödinger equation for a two-electron system [A.G. Abrashkevich, D.G. Abrashkevich, M. Shapiro, Comput. Phys. Comm. 90 (1995) 311-339] or a hydrogen atom in magnetic field [M.G. Dimova, M.S. Kaschiev, S.I. Vinitsky, J. Phys. B 38 (2005) 2337-2352] is reduced by separating the radial coordinate ρ from the angular variables to a system of second-order ordinary differential equations which contain potential matrix elements and first-derivative coupling terms. The purpose of this paper is to present the finite-element method procedure based on the use of high-order accuracy approximations for calculating approximate eigensolutions for such systems of coupled differential equations.Solution method: The boundary problems for coupled differential equations are solved by the finite-element method using high-order accuracy approximations [A.G. Abrashkevich, D.G. Abrashkevich, M.S. Kaschiev, I.V. Puzynin, Comput. Phys. Comm. 85 (1995) 40-64]. The generalized algebraic eigenvalue problem AF=EBF with respect to pair unknowns (E,F) arising after the replacement of the differential problem by the finite-element approximation is solved by the subspace iteration method using the SSPACE program [K.J. Bathe, Finite Element Procedures in Engineering Analysis, Englewood Cliffs, Prentice-Hall, New York, 1982]. The generalized algebraic eigenvalue problem (A−EB)F=λDF with respect to pair unknowns (λ,F) arising after the corresponding replacement of the scattering boundary problem in open channels at fixed energy value, E, is solved by the LDLT factorization of symmetric matrix and back-substitution methods using the DECOMP and REDBAK programs, respectively [K.J. Bathe, Finite Element Procedures in Engineering Analysis, Englewood Cliffs, Prentice-Hall, New York, 1982]. As a test desk, the program is applied to the calculation of the energy values and reaction matrix for an exactly solvable 2D-model of three identical particles on a line with pair zero-range potentials described in [Yu. A. Kuperin, P.B. Kurasov, Yu.B. Melnikov, S.P. Merkuriev, Ann. Phys. 205 (1991) 330-361; O. Chuluunbaatar, A.A. Gusev, S.Y. Larsen, S.I. Vinitsky, J. Phys. A 35 (2002) L513-L525; N.P. Mehta, J.R. Shepard, Phys. Rev. A 72 (2005) 032728-1-11; O. Chuluunbaatar, A.A. Gusev, M.S. Kaschiev, V.A. Kaschieva, A. Amaya-Tapia, S.Y. Larsen, S.I. Vinitsky, J. Phys. B 39 (2006) 243-269]. For this benchmark model the needed analytical expressions for the potential matrix elements and first-derivative coupling terms, their asymptotics and asymptotics of radial solutions of the boundary problems for coupled differential equations have been produced with help of a MAPLE computer algebra system.Restrictions: The computer memory requirements depend on:

•

(a) the number of differential equations;

•

(b) the number and order of finite-elements;

•

(c) the total number of hyperradial points; and

•

(d) the number of eigensolutions required.

Restrictions due to dimension sizes may be easily alleviated by altering PARAMETER statements (see Long Write-Up and listing for details). The user must also supply subroutine POTCAL for evaluating potential matrix elements. The user should supply subroutines ASYMEV (when solving the eigenvalue problem) or ASYMSC (when solving the scattering problem) that evaluate the asymptotics of the radial wave functions at the right boundary point in case of a boundary condition of the third type, respectively.Running time: The running time depends critically upon:

•

(a) the number of differential equations;

•

(b) the number and order of finite-elements;

•

(c) the total number of hyperradial points on interval [0,ρmax]; and

•

(d) the number of eigensolutions required.

The test run which accompanies this paper took 28.48 s without calculation of matrix potentials on the Intel Pentium IV 2.4 GHz.     

Classification and Uncertainty Visualization of Dendritic Spines from Optical Microscopy Imaging

Neuronal dendrites and their spines affect the connectivity of neural networks, and play a significant role in many neurological conditions. Neuronal function is observed to be closely correlated with the appearance, disappearance and morphology of the spines. Automatic 3‐D reconstruction of neurons from light microscopy images, followed by the identification, classification and visualization of dendritic spines is therefore essential for studying neuronal physiology and biophysical properties. In this paper, we present a method to reconstruct dendrites using a surface representation of the dendrite. The 1‐D skeleton of the dendritic surface is then extracted by a medial geodesic function that is robust and topologically correct. This is followed by a Bayesian identification and classification of the spines. The dendrite and spines are visualized in a manner that displays the spines' types and the inherent uncertainty in identification and classification. We also describe a user study conducted to validate the accuracy of the classification and the efficacy of the visualization.