基于固态Ag/AgCl参比电极的氧化钨pH电化学传感器的研究

通过浸涂法在钨金属丝上涂敷氧化钨氢离子敏感膜,制备了氧化钨H 选择性电极,采用尿素改性聚乙烯醇作为参比电极的固态薄膜材料并进行KCl掺杂,经Nafion膜进行修饰后制备了固态参比电极.利用自制的氧化钨pH电极与固态参比电极制成pH电化学传感器,该传感器具有良好的响应电位E-pH线性函数关系,响应范围为pH2～pH11.响应灵敏度与氧化钨的热处理温度有关,200℃热处理后的响应灵敏度为52.81 mV/pH, 响应时间与氧化钨敏感膜、测试溶液pH值以及溶液温度有关.在pH2→pH11→pH2循环测试过程中,传感器的滞后效应较小.该传感器有良好的选择性,响应行为不受Na 、F-等常见离子的影响,但是受到氧化还原性的NO-3、I-等离子的干扰.传感器内阻很低为22.8 kΩ,远小于玻璃pH计的内阻(1×109 Ω).该传感器在各种饮料中具有较高测量精度,与玻璃pH计的测量值进行对比,两者的差值在(-0.06 pH, 0.15 pH)范围内.在10-5M→10-1M柠檬酸溶液中,传感器的响应电位与溶液浓度存在良好的线性关系,响应时间小于1 min.     

基于微/纳米加工技术的微型电化学免疫传感器研究

生物传感器的研制越来越趋向于微型化、集成化、智能化以及无创伤的方向发展.研制基于微/纳米加工技术的电化学免疫传感器顺应了这一趋势,利用微电子机械系统(MEMS)技术在硅基芯片上制备微型三电极系统和SU-8微型池,并采用自组装单层膜和纳米金修饰微型电极表面用于抗体的固定化,研制出新型的电化学免疫传感器.研究表明,这种微型电化学免疫传感器易于实现批量生产,便于集成,检测过程只需要少量的样品,大大降低有毒试剂的消耗,减少环境污染,同时具有分析成本低,响应时间快,检测下限低和适用于现场快速检测等优点.     

海洋温盐深高精度测量集成微纳传感器制备及测试

海洋传感器技术在海洋军事作战领域发挥着重要的作用,随着人类探索海洋的未知领域,海洋传感器技术逐渐发展,但现阶段发展不完全,主要依赖进口,国产化率低.海水的温度、盐度、深度(温盐深)是海洋环境测量的基本参数,目前国内温盐深三参数传感器体积大、设备复杂、集成度低,难以满足实时在线检测的需求.本文基于微机电系统(MEMS)技...     

硅阵列探针上基于IrOx的pH传感器和电生理信号传感器

脑部区域的pH值是哺乳动物中枢神经系统(CNS)的重要环境参数,并与多种神经系统疾病相关.采用微机电系统(MEMS)工艺和电化学方法制造了由电化学电极点和电生理电极点组成的多功能密歇根探针.在多功能密歇根探针中,电生理电极点在1 kHz时具有10 kΩ的低阻抗,而电化学电极点则对pH值具有47 mV/pH的灵敏度.此多...     

中国微米纳米-微纳结构对电容式柔性压力传感器性能影响的研究

设计制备出三明治结构的电容式柔性压力传感器,并对其性能进行研究.该传感器以银纳米线为电极材料,聚二甲基硅氧烷(PDMS)为柔性衬底,同时采用毛面玻璃和光面玻璃分别作为柔性衬底的制备模板,制备出微纳结构和平面结构的PDMS薄膜.然后采用喷涂法制备AgNWs/PDMS复合电极,以另外一层PDMS为介电层,将两电极面对面封装,得到电容式柔性压力传感器,最后系统研究了传感器的电极微纳结构对器件性能的影响.本文研究表明,具有微纳结构的AgNWs/PDMS复合薄膜传感器的灵敏度为1.0 kPa-1,而平面结构的AgNWs/PDMS复合薄膜传感器的灵敏度为0.6 kPa-1,由此可知具有微纳结构的柔性衬底能够显著提高器件的灵敏度.     

用于快速生化检测的生物传感技术研究

本文介绍了用于检测多种生化参数的手持式多通道微系统的研制过程.该系统通过使用具有不同参数的薄膜电极传感器,可以测量多种生化参数.本文还介绍了利用薄膜电极传感器对其它多种生化参数(酮体、胆固醇、血红素、肌酸激酶等)进行的响应特性研究,并对传感器的响应线性范围、相关系数和精密度进行了详述.     

固态pH 探测电极的制备及其性能表征

我们采用熔融碳酸锂(LiCO3)氧化法制备了固态Ir／IrO2 pH电极，同时制备了改进型固态Ag／AgCl参比电极，并对它们的性能进行了表征。实验结果显示，在pH=0-14的溶液中，Ir／IrO2电极与参比电极电位差与pH值呈现良好的线性关系，直线斜率为-62．429mV／pH，截距为607．97mV，相关系数R2=0．993。温度对新型pH传感器响应信号的影响符合Nernst方程，易于进行温度校正。盐度对电信号强度的影响是线性的，在介质盐度已知，或向步测定介质盐度的前提下，可从响应电信号强度及盐度确定待测介质的pH值。     

基于集成参比电极的多参数水质监测微传感器阵列研制

研究了一种基于MEMS工艺制备的集成微电极型传感器,并用电化学修饰方法将Ag/AgCl参比电极集成在传感器上,用于水体中温度、电导率和氧化还原电位的测定.Pt温度传感器的电阻与温度的线性关系良好,满足温度测量精度的需求;比较法确定电导率传感器的电极常数为2.723,可以对一般水体的电导率进行测定;氧化还原电位传感器的标...     

用于低温环境的铂电阻温度微传感器

目前,铂电阻温度传感器主要应用于73 K(-200℃)以上环境的温度检测。设计了可用于10 K(-263℃)～200 K(-73℃)低温区的铂电阻温度微传感器。铂电阻温度微传感器采用对称的折回型结构,这种结构有效地降低了交流感抗的影响。传感器的敏感薄膜是一层采用磁控直流溅射沉积厚度为200 nm的铂薄膜。采用QD PPMS仪器测试传感器的电阻与温度的变化关系,得出传感器的电阻温度系数(TCR):研制的温度传感器的电阻温度系数在温度高于30K(-243℃)时可达到9980×10-6/K,同时在低于30K(-243℃)的深低温区域TCR也可达到3730×10-6/K。     

微操作/微装配中微力觉的测量与控制技术研究现状综述

微力觉的测量与控制技术是微操作/微装配领域内的核心内容和难点课题,是满足微器件可靠操作与无损装配要求的重要技术保障之一.本文介绍了微操作/微装配机器人系统的典型框架,并对各分系统的研究要点做了分析与回顾.然后,从微力觉的特点、微力测量方法与传感器、微力觉控制三个方面对微力觉的测量与控制技术的发展现状进行了综述.着重介绍了近些年在远程微操作系统和微操作/微装配系统中微力觉控制的方法及核心研究内容的研究成果.在此基础上,提出了微力觉测量与控制亟待解决的一些关键问题,并对这些关键问题的解决方案进行了探讨.最后,对微力觉的发展前景和方向进行了展望.     

M/G/c/K blocking probability models and system performance

An exact solution for the M/G/c/K model is only possible for special cases, such as exponential service, a single server, or no waiting room at all. Instead of basing the approximation on an infinite capacity queue as is often the case, an approximation based on a closed-form expression derivable from the finite capacity exponential queue is presented. Properties of the closed-form expression along with its use in approximating the blocking probability of M/G/c/K systems are discussed. Extensive experiments are provided to test and verify the efficacy of our approximate results.     

设计模式变体的描述与验证*

为解决标准设计模式演化后难以检测的问题,引入设计模式变体思想,以Bridge模式为例,给出了八种常用的变体实现,并以人工形式挖掘了四种开源系统中Bridge模式变体的基准数,接着在Apache Ant1.6.2与JHotDraw5.1开源系统中通过六种主流设计模式检测工具进行了变体检测实验。试验结果表明,FCA-CBR方法简单有效,对2种开源系统中Bridge模式变体检测的精确率达到60%与48.1%,与先前方法相比有了较大的提高。     

(r∞, n12, s12) measurements on the 2-CPU CRAY X-MP

We report performance measurements made on the 2-CPU CRAY X-MP at ECMWF, Reading. Vector (SIMD) performance on one CPU is interpreted by the two parameters ($\text{r}{}_{\mathrm{\infty }}\text{, n}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$), and we find for dyadic operations using FORTRAN $\text{r}{}_{\mathrm{\infty }}\text{= 70}\text{Mflop/s}\text{, n}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{= 53}\text{flop}$. All vector triadic operations produce $\text{r}{}_{\mathrm{\infty }}\text{= 107}\text{Mflop/s}\text{, n}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{= 45}\text{flop}$; and a triadic operation with two vectors and one scalar gives r_∞ = 148 Mflop/s and $\text{n}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{= 60}\text{flop}$. MIMD performance using both CPUs on one job is interpreted with the two parameters ($\text{r}{}_{\mathrm{\infty }}\text{, s}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$), where $\text{s}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ is the amount of arithmetic that could have been done during the time taken to synchronize the two CPUs. We find, for dyadic operations using the TSKSTART and TSKWAIT synchronization primitives, that r_∞ = 130 Mflop/s and $\text{s}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{= 5700}\text{flop}$. This means that a job must contain more than ～ 6000 floating-point operations if it is to run at more than 50% of the maximum performance when split between both CPUs by this method. Less expensive synchronization methods using LOCKS and EVENTS reduces $\text{s}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ to 4000 flop and 2000 flop respectively. A simplified form of LOCK synchronization written in CAL code further reduces $\text{s}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ to 220 flop. This is probably the minimum possible value for synchronization overhead on the CRAY X-MP.     

Complex random sample scheduling and its application to an N/M/F/Fmax problem

“Complex Random Sample Scheduling(CRSS)” was proposed in this paper as an efficient heuristic method for solving any permutation scheduling problems. To show the effectiveness of the proposed CRSS, it was applied to an N-job, M-machine, permutation flowshop scheduling problem to minimize makespan, N/M/F/F_max. Numerical experiments made it clear that the proposed CRSS provides a schedule very close to the near-optimal schedule obtained by the existing promising heuristic methods such as taboo search and simulated annealing, within less computation time than these heuristic methods.     

Geom/G/1/n system with LIFO discipline without interrupts and constrained total amount of customers

Consideration was given to the discrete-time queuing system with inversive servicing without interrupts, second-order geometrical arrivals, arbitrary (discrete) distribution of the customer length, and finite buffer. Each arriving customer has length and random volume. The total volume of the customers sojourning in the system is bounded by some value. Formulas of the stationary state probabilities and stationary distribution of the time of customer sojourn in the system were established.     

Efficient implementation of Johnson''s rule for the n/2/F/Fmax scheduling problem

Several efficient algorithms of O(n log n) computational complexity, for the Johnson's rule to schedule a set of simultaneously available jobs on two machines in a flowship to minimize the maximum job flowtime have appeared in the literature. A modified version of one of these algorithms is presented which not only simplifies the programming effort for implementation but is also able to generate all possible optimal sequences obtainable from Johnson's rule.     

On the M/Ck/1 queue

We obtain the exact analytic expression of the probability distribution of the number of units in a single server queue with Poisson arrivals and Coxian service time distribution (notated as M/C_k/1). A recursive procedure for calculating this probability distribution is given. The well-known queues M/E_k/1 and M/D/1 are re-derived as special cases of the M/C_k/1 queue. Finally, the cases of M/C₂/1 and M/C₃/1 are fully worked out.