Anaerobic fermentation of xylose by pichia stipitis: The effect of forced cycling of ph

Xylose fermentation by Pichia stipitis was examined using a two-stage batch process. The cells were first grown aerobically on D-xylose (5 g/L), whereafter additional xylose (10 g/L) was added and fermented during anaerobic conditions (T=30°C). The optimum pH value for a fermentation with constant pH was found to be 4.5 (maximum specific ethanol production rate 0.21 g/(g h). Forced square wave cycling of the pH between 4 and 5, and 3.5 and 5.5 (cycle time 30 min) during the fermentation stage resulted in a fermentation rate lower than the maximum rate, but with unchanged ethanol yields.     

一种汽轮机组排汽焓和最优初压在线计算方法

通过对已往的汽轮机变工况计算方法的分析,提出了以汽轮机末级抽汽或次末级抽汽(过热蒸汽状态)为计算起点的汽轮机顺序变工况核算方法。根据初始假定的末级流量和现场实际的末级前热力状态和背压,用汽轮机变工况流型判别准则,判别级的流型,然后从末级前参数开始顺序进行一次级的变工况核算,得到新的排汽焓,最后算得机组热耗率和排汽焓。以此方法为变工况计算的基础,并利用系统分析方法,建立了在线确定单元机组最优运行初压的数学模型。为火电机组的优化运行提出了一种新思路。     

前置反射式发射率在线测量装置的研制

针对目前军事、航空航天、工农业等领域对在线发射率测量的迫切要求,设计了新型的前置反射式发射率在线测量装置.采用立体角比例划分法构建了前置反射器模型,设计了光纤式多光谱仪作为光谱接收装置.根据测量装置的结构特点,建立了在线发射率测量的理论模型.测量了700~1100℃温度范围内的不锈钢氧化层发射率,结果符合金属氧化物发射率的一般规律.实验结果证明了此在线发射率测量装置可满足一定条件下的发射率测量需要.     

基于TD-SCDMA的煤矿智能电力故障检测与分析系统

针对煤矿井下供电设备故障给煤矿安全生产带来很大隐患的问题,提出了一种基于TD-SCDMA技术的煤矿智能电力故障检测与分析系统。该系统通过供电检测采集系统实时采集各段母线电压、各分支电流、功率、断路器状态以及故障信息,然后通过TD-SCDMA/工业以太网络支撑系统将煤矿供配电系统各设备运行状态、运行参数、故障信息传输到智能电力故障分析系统,完成煤矿供配电系统的信息加工、分析和故障诊断与处理。应用结果表明,该系统提高了供电可靠性,为煤矿的安全生产提供了保障。     

数控机床位置伺服在线调试与动态性能分析研究

介绍一种在数控机床位置伺服系统在线调试中应用系统动态性能分析方法的基本原理，给出了一种位置伺服系统动态响应曲线、动态性能分析及其主要技术指标的实例。     

压力传感器在线状态监测装置研发

目前煤炭输送皮带采用双托辊(2个传感器)或四托辊(4个传感器)并采取传感器输出信号并联方法,以此提高皮带秤的准确性和稳定性.然而该并联方法无法对传感器进行独立采集,同时影响了传感器的故障判断.采用MSC1210Y5单片机和信号分离器,设计并联称重传感器系统的压力传感器状态在线监测装置,实现多个压力传感器并联应用时的独立采集;设计压力传感器在线状态比对算法,将不断变化的称重累计量转换为定量值,解决称重累计量为变量而无法准确在线监测的技术弊端.测试结果表明该装置较好地满足了压力传感器独立采集的要求,为称重计量装置等集中监控提供有效手段.     

油液在线监测技术研究进展

油液在线监测技术是机械故障智能诊断的重要发展方向,传感器作为其关键元件,发挥着重要作用。对油液在线监测的粘度传感器、水分传感器、磨粒传感器以及多传感器集成的国内外研究进展进行了介绍。从电磁法、静电法、电感法、图像识别几个方面对磨粒测量与分析的国内外研究进行了介绍。提出了现阶段存在的不足,对油液在线监测的未来发展之路进行了展望。     

Multi-sensor information fusion estimators for stochastic uncertain systems with correlated noises

The information fusion estimation problems are investigated for multi-sensor stochastic uncertain systems with correlated noises. The stochastic uncertainties caused by correlated multiplicative noises exist in the state and observation matrices. The process noise and the observation noises are one-step auto-correlated and two-step cross-correlated, respectively. While the observation noises of different sensors are one-step cross-correlated. The optimal centralized fusion filter, predictor and smoother are proposed in the linear minimum variance sense via an innovative analysis approach. To enhance the robustness and flexibility, a distributed fusion filter is put forward, which requires the calculation of filtering error cross-covariance matrices between any two local filters. To avoid the calculation of cross-covariance matrices, another distributed fusion filter is also presented by using the covariance intersection (CI) fusion algorithm, which can reduce the computational cost. A simulation example is given to show the effectiveness of the proposed algorithms.     

iPods in the Sauna or Kids These Days….

Abstract

Inter-play, an on-line index to plays in collections, anthologies and periodicals, provides easy access to the locations of printed plays by making citations for the location(s) of each play searchable by author and/or title. The process of converting the original card file play index into an electronic database available on the World Wide Web is described. The index has been designed to provide easy access to and broad coverage of available plays. New titles are added to the file on a regular basis, placing this Web publication squarely in the electronic journal arena.     

一种DDOS在线检测法

由DDoS攻击时流量样本与Hurst指数的关系,得到检测DDoS的方法.以提升小波估计Hurst指数法为基础,设计出小波算法的能谱在线计算方法.与传统检测法相比,本法可在线观察业务流特征,能及时发现DDOS入侵。