一种新型溶解氧敏感材料的制备和研究

该实验合成了基于Pt席夫碱配合物的一种新型溶解氧敏感材料。它对溶解氧有灵敏响应(IN2/IO2=83),其Stern-Volmer曲线有良好的线性,并具有良好的重现可逆性。这是席夫碱金属配合物的又一新应用,具有良好的应用价值。     

生物工程用可消毒溶解氧电极的研制

该文介绍研制可消毒溶解氧电极的原理、构造、工作方式与主要技术参数.对电极的关键技术和材料的特性进行探讨,研制电极的材料完全使用国产的,电极性能良好.并已应用在生物发酵过程中溶解氧在线检测和控制.     

微生物发酵过程中溶解氧的控制研究

溶解氧(DO)是微生物发酵过程中重要参数之一。本文介绍了基于泛布尔代数的溶解氧控制器控制算法和控制器硬件,它能够准确可靠地对溶解氧进行在线检测和控制。     

多路并行信号检测仪的设计与实现

本文先介绍了多路并行数字信号检测仪的工作原理和设计流程,重点讨论了该检测仪的设计方案和实现策略.根据设计要求,将系统划分为采集处理模块和主控模块.然后分析对比了不同方法实现这两个模块的优缺点和适应场合,最后结合本文设计的检测仪的应用特点,给出了详细的实现方法.     

新型鞋内安全检测仪设计与实现

鞋内安全检测仪是专对鞋内、鞋跟及鞋底暗藏金属违禁品进行非破坏性检查的设备,弥补安检类产品对各类鞋子检测的盲区。原有鞋内安全检测仪存在探测范围小,限制了它的推广使用。本文介绍一种新型鞋内安全检测仪,该检测仪扩大对鞋子的检查范围,同时分析此检测仪的基本检测原理,并简述了电路的实现过程和一些关键技术的解决方法。     

基于嵌入式结构的便携式漏磁检测仪设计

针对基于工控机设计的漏磁检测仪体积大、功耗高、操作不便等问题,设计了一种基于嵌入式技术的便携式漏磁检测仪.该检测仪以S3C2440A嵌入式微处理器为核心,采用Windows CE 5.0嵌入式操作系统,通过霍尔传感器捕获缺陷漏磁信号,完成对铁磁材料工件机械结构缺陷的检测.实验结果表明:该仪器具有灵敏度高、结构简单、便于携带等优点,具有一定的推广价值.     

多路并行信号检测仪的设计与实现

本文先介绍了多路并行数字信号检测仪的工作原理和设计流程,重点讨论了该检测仪的设计方案和实现策略。根据设计要求,将系统划分为采集处理模块和主控模块。然后分析对比了不同方法实现这两个模块的优缺点和适应场合,最后结合本文设计的检测仪的应用特点,给出了详细的实现方法。     

网络化杂散电流检测仪设计

针对杂散电流的产生、危害及其检测原理的分析,提出了以单片机为核心的网络化杂散电流检测仪的设计。详细讨论了检测仪的信号调理电路、存储和显示电路、时钟电路及CAN总线接口电路设计和软件设计。该系统通过CAN总线,实现对杂散电流的网络化检测。     

微生物深层发酵过程溶解氧控制器设计

溶解氧(DO)是微生物发酵过程中重要参数之一。介绍了溶解氧控制器的一种设计方法和一个实际控制器，它能够准确可靠地对溶解氧进行在线检测和控制。     

高体积分数溴气传感器

描述了目前溴气传感器的发展状况,介绍了一种用于高体积分数测量的溴气传感器,阐述了它的工作原理,对电极材料、薄膜材料、电解液、电路等关键技术进行了讨论,给出了它的结构,讨论了性能特点及影响因素。     

一种新型的Pt􀀁LaF3 混合膜MISFET 结构溶解氧传感器

基于碳糊成模（carbon paste film forming)方法,我们研制了一种MISFET结构的Pt-LaF混合膜全固态溶解氧传感器,对传感器的器件结构以及Pt-LaF3敏感膜的敏感机制和响应特性进行了分析,并实际测试了器件特性。给出了在不同工作点和不同温度条件下器件的输出电压对溶解氧浓度变化的响应曲线。实验结果表明,我们所提出的器件可以用于测量溶解氧含量。     

智能型溶解氧监测仪的设计

介绍了采用极谱式氧电极和单片机等组成的智能型溶解氧监测仪的原理及软硬件设计方法。该监测仪较好地克服了国内现有溶解氧分析仪的诸多缺点，是集溶解氧和溶解氧变化速率测定与自动监测于一身的智能型溶解氧监测仪。     

Oxygen control for an industrial pilot-scale fed-batch filamentous fungal fermentation

Industrial filamentous fungal fermentations are typically operated in fed-batch mode. Oxygen control represents an important operational challenge due to the varying biomass concentration. In this study, oxygen control is implemented by manipulating the substrate feed rate, i.e. the rate of oxygen consumption. It turns out that the setpoint for dissolved oxygen represents a trade-off since a low dissolved oxygen value favors productivity but can also induce oxygen limitation. This paper addresses the regulation of dissolved oxygen using a cascade control scheme that incorporates auxiliary measurements to improve the control performance. The computation of an appropriate setpoint profile for dissolved oxygen is solved via process optimization. For that purpose, an existing morphologically structured model is extended to include the effects of both low levels of oxygen on growth and medium rheological properties on oxygen transfer. Experimental results obtained at the industrial pilot-scale level confirm the efficiency of the proposed control strategy but also illustrate the shortcomings of the process model at hand for optimizing the dissolved oxygen setpoints.     

Micromachined dissolved oxygen sensor based on solid polymer electrolyte

A silicon microprobe to measure dissolved oxygen levels is described. The sensors are prepared by overlaying platinum thin film electrodes with a solid state proton conductive matrix (PCM) coating. The platinum thin film electrodes are fabricated on silicon substrates by standard photolithographic techniques while the PCM coating is achieved by drop-casting methods. The size and materials of the device make it potentially suitable for medical implantation. The devices are tested in deionized water (DI water), phosphate buffered saline (PBS), and bovine blood serum (BBS). Through linear sweep voltammetry (LSV), single devices are shown to have decent performances in terms of long term stability, reliability, hysteresis, linearity, and sensitivity. Variations among different devices are characterized and correlated. The simplicity and cost effectiveness of the fabrication and packaging procedures and the decent in vitro performances of these devices make them good candidates as miniaturized, disposable, and implantable dissolved oxygen sensors for biological and biomedical use.     

无铅原电池式氧传感器

介绍了一种原电池式氧传感器,以锡代替铅作阳极,以有机酸水溶液作电解质,避免铅造成环境污染。该传感器环保安全,响应快速,性能稳定且操作便捷,可在便携式测氧仪和溶氧测定仪器中使用。     

A digital water quality controller for polluted streams

A procedure is described for designing a digital controller for maintaining the level of dissolved oxygen in a polluted river. The controller generates discrete-time profiles for aeration input and rate of effluent discharge which are used as the controls. Simulation results show that the digital controller performs quite well compared to the continuous-time controllers described in an earlier paper (Gourishankar and Ramar 1977). Computer simulation results are presented to show that the digital controller, designed on the basis that the river system model parameters are constant, performs well with seasonal temperature variations which affect the model parameters.     

Influence of Matrices on Oxygen Sensing of Three Sensing Films with Chemically Conjugated Platinum Porphyrin Probes and Preliminary Application for Monitoring of Oxygen Consumption of Escherichia coli (E. coli)

Oxygen sensing films were synthesized by a chemical conjugation of functional platinum porphyrin probes in silica gel, polystyrene (PS), and poly(2-hydroxyethyl methacrylate) (PHEMA) matrices. Responses of the sensing films to gaseous oxygen and dissolved oxygen were studied and the influence of the matrices on the sensing behaviors was investigated. Silica gel films had the highest fluorescence intensity ratio from deoxygenated to oxygenated environments and the fastest response time to oxygen. PHEMA films had no response to gaseous oxygen, but had greater sensitivity and a faster response time for dissolved oxygen than those of PS films. The influence of matrices on oxygen response, sensitivity and response time was discussed. The influence is most likely attributed to the oxygen diffusion abilities of the matrices. Since the probes were chemically immobilized in the matrices, no leaching of the probes was observed from the sensing films when applied in aqueous environment. One sensing film made from the PHEMA matrix was used to preliminarily monitor the oxygen consumption of Escherichia coli (E. coli) bacteria. E. coli cell density and antibiotics ampicillin concentration dependent oxygen consumption was observed, indicating the potential application of the oxygen sensing film for biological application.     

Bioreactor profile control by a nonlinear auto regressive moving average neuro and two degree of freedom PID controllers

This paper presents the use of nonlinear auto regressive moving average (NARMA) neuro controller for temperature control and two degree of freedom PID (2DOF-PID) for pH and dissolved oxygen (DO) of a biochemical reactor in comparison with the industry standard anti-windup PID (AWU-PID) controllers. The process model of yeast fermentation described in terms of temperature, pH and dissolved oxygen has been used in this study. Nonlinear auto regressive moving average (NARMA) neuro controller used for temperature control has been trained by Levenberg–Marquardt training algorithm. The 2DOF-PID controllers used for pH and dissolved oxygen have been tuned by MATLAB's auto tune feature along with manual tuning. Random training data with input varying from 0 to 100 l/h have been obtained by using NARMA graphical interface. The data samples used for training, validation and testing are 20,000, 10,000 and 10,000 respectively. Random profiles have been used for simulation. The NARMA neuro controller and the 2DOF-PID controllers have shown improvement in rise time, residual error and overshoot. The proposed controllers have been implemented on TMS320 Digital Signal Processing board using code composure studio. Arduino Mega board has been used for input/output interface.