基于Lab VIEW与MATLAB混合编程的气液两相流测量软件开发

测量气液两相流量需要实时获取大量的数据和快速求解复杂的计算模型,单独采用LabVIEW或者MATLAB对其测量软件进行开发效率较低。为了高效地开发功能强大的虚拟仪器软件,应用动态链接库技术实现了LabVIEW与MATLAB的混合编程,在此基础上开发了用于气液两相流组合测量装置的软件,解决了气液两相流参数测量系统需要进行大量数据实时采集、处理、显示、保存以及复杂多相流模型求解等问题。该软件开发方法适用于对人机交互界面、数据采集、仪器控制和数值计算同时具有较高要求的场合,可广泛应用于实验室和实际生产系统。     

用于气固两相流流速测量的嵌入式相关器设计

工、农业生产中广泛涉及气固两相流体系,气固两相流本质是一种多相流,测量非常困难,静电传感器与相关测量技术的结合,为气固两相流速度测量提供了解决方案。本文利用兼具微处理器和数字信号处理器优点的数字信号控制器（Dsc）,设计制作低功耗、控制灵活的实时在线嵌入式相关系统。通过在气固两相流实验装置上的实验研究表明,该系统有较高的实时性和测量精度。     

传感器在物理实验教学中的应用

将传感器与计算机及接口电路结合 ,应用于物理实验中 ,可实现对数据的在线实时采集、处理、成像 ,提高测量精度 ,优化实验过程     

利用DASP测试软件实现流体机械性能的综合实验

利用DASP软件与传感器、控制元件、计算机等建立典型流体机械性能的测试系统,实现流体机械性能实验中动态参数的采集、整理、计算和分析,用以完成气缸内瞬态压力曲线和气阀阀片的运动规律曲线等录测及示功图的转换与分析。根据测试系统监测获取的实测数据,进行动态参数分析和实时计算指示功率、轴功率、容积流量及功率损失和效率等,并可通过改变转速、改变压力比进行性能的对比实验。另外系统可根据对比数据进行变工况的经济性分析,寻找最佳参数及适宜的热力工况。实验中系统简化,测试方案灵活,具有测量精度高、测试速度快、操作直观和数据存储方便等特点。     

高压水合物/蜡沉积实验环路的设计与建设

针对深海开发海底管道流动安全保障领域内的研究,设计并建设了一套高压水/蜡沉积合物实验环路.通过借鉴国内外著名环路的设计优点及结合自身课题的研究需要,进行了相应的改进与创新,其设计功能为既可进行水合物浆液的单相、多相流动实验,也可进行多相流动蜡沉积实验,为目前世界上为数不多的几套可以同时实现此两项功能的高压实验环路.该套实验装置不仅耐压程度高(15MPa),温控范围较广(- 10～100℃),测试段管径可换(2.54 cm与5.08 cm),整体设计合理以及测量仪表精密,而且还引进了包括FBRM(在线颗粒分析仪)在内的国际上最为先进的实验仪器,使得此实验装置的科技含量与技术水平有了质的飞跃,达到国内一流、国际先进的水平,可应用于水合物浆液多相管流规律和蜡沉积规律的科研工作.     

湿天然气输气管道内液膜测试的实验装置开发

研制了一套模拟测试湿天然气输气管道内液膜的实验装置。实验装置由供液系统、抽气系统、液膜厚度测试系统、管内液滴粒径测试系统、管路系统等组成。管路系统采用有机玻璃制成,便于观察管内气液两相或多相流流态;管路设计为可拆卸连接,便于研究管道形状、管内表面粗糙度等对管内液膜分布的影响规律;气体、液体流量比例可调,便于实现管内泡状流、塞状流、分层流、波状流、弹状流和环状流等流态。该实验装置可开展不同结构参数、操作参数、物性参数对管道内多相流流态、管壁液膜分布特性、液滴浓度分布特征影响的实验研究。     

基于Web使用挖掘的e-Learning自适应推荐系统

e-Learning自适应推荐系统是一种基于当前学习者联机行为,在线自动推荐学习对象而不需要学习者直接反馈的系统。该系统框架是由离线模块和在线模块构成。离线模块预处理数据建立学习者模型,在线模块使用这些模型实时识别学习者目标,运用基于协作过滤的一系列推荐策略预测推荐学习对象。实验证明:由于实现模型构建和模型应用的有效分离,该系统具有较强的伸缩性和较快的实时响应速度,适合为大规模e-Learning系统提供高质量的个性化推荐服务。     

利用单片机实现一种误差补偿方法研究

从实际出发,介绍了一种利用单片机系统对数据进行实时采集及离线处理,从而实现最终的误差补偿的方法.实践证明,该方法切实有效,提高了系统的精度.     

基于Spark流式计算的实时电影推荐研究

基于Hadoop平台的实时电影推荐系统在需要大量迭代计算时运行速度明显变慢,无法根据用户行为作出实时反馈。针对以上问题,设计基于Spark流式计算的实时电影推荐系统,可更好地满足用户实时需求。基于Spark流式计算的实时电影推荐系统将传统电影推荐算法与Spark流式计算方法相结合,在线部分使用Spark Streaming实时接收用户模拟评分,并使用Scoket编程模拟用户浏览商品时产生的实时日志数据。日志数据包括用户当前浏览电影、观看电影次数、停留时间与是否购买该商品,再使用Spark Streaming构建实时数据处理系统,计算出当前用户相关度最高的电影并进行推荐。实验结果表明,基于Spark 平台的电影实时推荐系统在离线推荐训练过程中,训练速度相对于Hadoop 平台有明显提高,能根据用户行为作出实时反馈,并向用户进行电影推荐。     

在线检测控制化学实验系统

大学生从使用常规化学实验仪器,到综合化学实验中利用大型仪器进行实验是一个大的跨越。而在常规化学实验中开设的计算机在线检测控制实验则正是这步跨越的衔接桥梁之一。着重介绍了在线检测控制化学实验系统的开发与实践,其特点在于不仅具有常见的计算机在线数据实时采集功能,更重要的是实现了计算机对化学实验过程的控制。     

Study on absorption coefficients of dual-energy γ-rays in determining phase fractions of multiphase flows

This paper discusses the principle and mathematical method to measure the phase fractions of multiphase flows by using a dual-energy gamma-ray system. The dual-energy gamma-ray device is composed of radioactive isotopes of 241Am and 137Cs with emission energies of 59.5 keV and 662 keV respectively. A rational method to calibrate the absorption coefficient was introduced in detail. The statistical error has been analyzed on the basis of the accurate absorption coefficient which enables determination phrase fractions almost independent of the flow regime. Improvement has been achieved on the measurement accuracy of phase fractions.     

Study on absorption coefficients of dual-energy γ-rays in determining phase fractions of multiphase flows

INTRODUCTION The imaging and measurement of multiphase flows has received much attention in recent years, largely because of a need in the oil industry to measure the mass flow rates of oil, water and gas in production pipelines, and the ability to see through objects and make quantitative measurements of the enclosed ma- terials and structures has wide range of applications. However, measurement over a wide range of flow regimes and the ability to very accurately measure the mass flow rat…     

Volumetric fraction measurement in oil-water-gas multiphase flow with dual energy gamma-ray system

INTRODUCTION Oil-water-gas multiphase mixed transport in oil pipe is extensively used in ocean oil industries. How to measure the volumetric fractions of oil-water-gas multiphase flow is an important subject of study in the oil industry. Related research work was started in the 1980s. The measurement of component ratios in multiphase flows using γ-ray attenuation was first suggested by Abouelwafa and Kendall (1980), and the technique has been used in many current com- mercial multiphase…     

Sample Size Requirements in Single- and Multiphase Growth Mixture Models: A Monte Carlo Simulation Study

Just as growth mixture models are useful with single-phase longitudinal data, multiphase growth mixture models can be used with multiple-phase longitudinal data. One of the practically important issues in single- and multiphase growth mixture models is the sample size requirements for accurate estimation. In a Monte Carlo simulation study, the sample sizes required for using these models are investigated under various theoretical and realistic conditions. In particular, the relationship between the sample size requirement and the number of indicator variables is examined, because the number of indicators can be relatively easily controlled by researchers in many multiphase data collection settings such as ecological momentary assessment. The findings not only provide tangible information about required sample sizes under various conditions to help researchers, but they also increase understanding of sample size requirements in single- and multiphase growth mixture models.     

微机配合刚体转动仪测量刚体转动惯量

用刚体转动仪测量刚体转动惯量实验所要测量的主要物理量是时间，所测量的实验数据繁多（一次实验要测量150多个），且要求准确，并且后续的实验数据处理计算非常繁杂。本文介绍了一种测量时间、计算转动惯量数值两项工作全部由PC机来完成的新方法。从硬件和软件方面详细说明了如何用一台微机实现对整个实验系统中所有实验进行时间量的测量和对实验数据的处理。此方法接口电路简单，时间测量准确，计算速度快，实验结果误差小，而且易于推广。     

Fault location of two-parallel transmission line for double phase-to-earth fa ult using one-terminal data

INTRODUCTIONTransmissionlinesofapowersystemaresubjecttomanykindsoffaults.Theprincipaltypesare :phase to earth ;doublephase to earth(phase phase earth) ;phase to phase ;three phase.Followingtheoccurrenceofatransmis sionlinefault,themaintenancecrewmustfinda…     

Fault location of two-parallel transmission line for double phase-to-earth fault using one-terminal data

An accurate algorithm for fault location of double phase-to-earth fault on transmission line of direct ground neutral system is presented. The algorithm, which employs the faulted phase network and zero-sequence network as fault-location model in which the source impedance at the remote end is not involved, effectively eliminates the effect of load flow and fault resistance on the accuracy of fault location. The algorithm achieves accurate location by measuring only one local end data and is used in a procedure that provides automatic determination of faulted types and phases, and does not require the engineer to specify them. Simulation results showed the effectiveness of the algorithm under the condition of double phase-to-earth fault. Project (No. 023801211) supported by the Key Science Foundation of Tianjin, China     

Numerical study on the flow features of U-beam inertial separator

Detailed parametric study of three-dimensional gas-particle multiphase flow characteristics in U-beam tube bundle inertial separators was conducted by numerical simulation. The carrier phase was treated in the Eulerian frame, the particles were tracked in the Lagrangian frame, and particle-wall collision was considered. Simulation carried out at different inflow rate and mass loading ratios revealed the pressure losses in the separators, velocity field of the gas phase, and the trajectories of particles. The study results revealed the multiphase flow-dynamic features of the separators, and the relationship between separator pressure losses and different inlet velocity. The numerical simulation can provide basis both for optimal design of impacting-inertial separator used in circulating fluidized bed boiler; and for study of gas-particle multiphase circumfluence flow. Project supported by the Zhejiang Provincial Natural Science Foundation of China (No. 500065)     

Computed tomography using level set method and algebraic reconstruction technique

In this paper, a novel reconstruction technique based on level set method and algebraic reconstruction technique is proposed for multiphase flow computed tomography (CT) system. The curvature-driven noise reduction method is inserted into the conventional iteration procedure of algebraic reconstruction technique to improve the image quality and convergence speed with limited projection data. By evolving the image as a set of iso-intensity contours after each updation, the sufficient number of iterations for acceptable results is reduced by 80%-90%, while the image quality is enhanced obviously. Quantitative evaluation of image quality is given by using both relative image error and correlation coefficient. The resultant images can be utilized to detect flow regimes for monitoring industrial multiphase flow. Laboratory results demonstrate the feasibility of the proposed method. Phantoms of four typical flow regimes can be reconstructed from few-view projection data efficiently, and the corresponding image errors and correlation coefficients are acceptable for the cases tested in this paper.