Three-way PLS regression and dual energy gamma densitometry for prediction of total volume fractions and enhanced flow regime identification in multiphase flow

Dual energy gamma densitometry and 3-way partial least squares regression were applied to quantify the total volume fractions and improve flow regime identification in multiphase flow. Multiphase flow experiments were carried out with formation water, crude oil and gas from different North Sea gas fields in Statoil׳s High Pressure Multiphase Flow Loop in Porsgrunn, Norway. Four different flow regimes were investigated (stratified wavy, slug, dispersed and annular). A traversable dual energy gamma densitometer was used to measure the fluid densities in the pipe. Partial least squares regression was previously applied to identify multiphase flow regimes and quantify volume fractions of gas, oil and water. That study showed promising results for flow regime identification but the predictions of the total volume fractions were not acceptable. In this study a new method combining gamma densitometry and 3-way partial least squares regression was applied in order to improve the quantitative estimation of the total volume fractions gained in the previous study. The proposed 3-way regression approach allows prediction of the total volume fractions directly using one model instead of multiple models which was reported earlier. The improved quantification of the volume fractions of gas, oil and water was used to improve the flow regime identification plots and increase the interpretability.The new 3-way prediction results for the volume fractions were significantly better than what was found earlier based on individual PLS models. The root mean square error of prediction for gas, oil and water from the 3-way PLS models were 4.1 %, 4.3 % and 4.6% respectively. All models reported were validated based on independent data (test set validation).     

基于悬浮液拟均相处理的轴承腔两相介质流动

针对航空发动机轴承腔中润滑油滴与气相介质的混合介质处理问题,提出基于悬浮液理论的混合介质拟均相处理技术,将轴承腔中润滑油滴与气相介质的混合流体形态转换为拟均相介质流体形态,形成拟均相介质等效物理参数计算方法。采用提出的拟均相处理方法,分析轴承腔两相介质流场,揭示了若干工况条件下的拟均相介质压力和速度的分布规律,并与其它同类型方法及试验的结果进行了对比。结果表明,基于悬浮液理论的拟均相处理方法可以运用于对轴承腔中润滑油滴/气相介质的处理上,并且有更好的效果。     

双相钢00Cr25Ni7M03NA冷轧管材工艺研究

在试制双相钢00Cr25Ni7M03NA钢管时,采用挤压＋冷轧＋冷拔工艺,发现热加工热塑性差。主要表现在制坯时开裂,挤压管坯内外表面时有裂纹,冷轧抗力大,道次变形量小,冷拔前打钳把断裂。成品管检验结果表明,化学成分、性能等技术指标达到技术要求,工艺路线成熟。     

河套灌区玉米膜下滴灌灌溉制度研究--测试文章

为研究河套灌区膜下滴灌条件下玉米高产、节水、高效的灌溉制度,通过两年的田间试验,分析了膜下滴灌条件下玉米的耗水量规律,用Jensen模型建立了玉米的水分生产函数,并对玉米的灌溉制度进行了优化。结果表明：膜下滴灌条件下玉米在苗期对水分的敏感性较弱,此时期缺水对产量的影响较小;在拔节—抽雄、抽雄—花期和花期—灌浆期对水分的敏感性较强,此时期亏水将会减产。 对玉米膜下滴灌灌溉制度优化得出：灌溉定额为275～325 mm,玉米的产量较高;对灌水量的分配为苗期—拔节灌水量为20～40 mm,拔节—抽穗的灌水量为40～60 mm,抽雄—开花的灌水量为115 mm,开花—灌浆的灌水量为80 mm,灌浆—乳熟的灌水量为20～40 mm,较本地常规地面灌每公顷节水2 546.25～3 296.25 mm,节水效果十分显著。     

铅炭蓄电池充电电压的研究

在混合动力汽车的运行模式下,对铅炭电池采用合理的充放电制度不仅能够高效率地回收汽车的刹车能量,而且还能延长电池的使用寿命。本文测试了高倍率、部分荷电状态（HRPSoC）下充电限制电压在2.5～2.83 V/单格范围内电池循环寿命和正负极电极电位的变化。实验结果表明：在该循环寿命测试制度下,充电限制电压设定在2.67 V/单格时电池的循环寿命最长,极化也较小。     

欧美食品安全监管经验及其启示

美国、欧盟等国家与地区在食品监管机构改革、食品安全信息公开透明、安全监管立法、食品身份认证等方面均积累了丰富的经验。针对他们确保食品安全的做法进行深入剖析和思考,并对中国目前的食品安全监督管理现状进行反思,提出构建加强食品安全监督和管理相关部门之间协作的网络,实施涵盖从田间到餐桌的全程监制体系,逐步推进食品安全监督和管理的相关法律,从而构建良性运行的中国食品安全监督与管理机制。     

Experimental research on heat transfer of water in tubes with conical ring inserts in transient regime

Forced convective of water in horizontal tubes with conical tube inserts has been studied experimentally. The transient flow regime has been used for the tests. Experimental results are validated with existing well established correlation. The turbulators were placed in two different arrangements: converging conical ring, referred to as CR array and diverging conical ring, DR array. Two correlations for the Nusselt number based on the experiment are introduced for practical use. It is found that the insertion of turbulators has enhanced the Nusselt number for the DR arrangement up to 521%, and for the CR arrangement up to 355%, although using the turbulators cause a significant increase in pressure drop.     

基于AT89S52的水情遥测终端设计与实现

设计了一种基于单片机的低功耗水情遥测终端,实现多种水情数据的采集、处理和报送。终端采用AT89S52单片机作为硬件核心,由扩充存储器、实时时钟、键盘输入、液晶显示、串行通信、调制解调及太阳能供电等外围电路构成。同时具备数字和模拟数据采集接口,通过连接相应传感器,实时采集雨量、水位、闸位、流量、温度等信息,使遥测参数多样化。显示模块与按键配合,用于动态显示、设置参数及系统的检测维护。设计的RS-232通信接口,可连接SMS/GSM、GPRS、无线电台等通信模块,满足不同通信方式下的应用,提高了通用性。该终端在实际应用中亦能稳定可靠地工作,满足水情遥测的功能和性能等技术要求。     

基于空气、冰与水物理特性的冰情检测系统

为了实现一种新的定点冰水情自动检测方法,利用空气、冰与水的电阻及温度特性差异规律,通过分层检测获取电阻与温度数据来实现对冰层厚度、冰层内部温度梯度与冰下水位的自动连续检测。在此基础上研制了电阻–温度式冰水情传感器与冰情连续自动数据检测系统,并在南极科考、黄河冰情预报等科研和水电工程中进行了冰情检测现场应用。通过工程应用实践证明,该方法对冰水情进行连续自动检测是完全可行的。     

Principle and Applications of Drying Characteristic Functions

ABSTRACT

This article focuses on the concept of a ‘drying characteristic function,’ which is an effective way to correlate drying rate curves for convective drying of homogeneous nonporous, hygroscopic porous and non-hygroscopic porous materials. The characteristic function, obtained bv a certain transformation of a drying rate curve, is independent of drying conditions and hence characterizes the transport kinetics in the material. The principle and some applications of the functions are reviewed. The first application is estimation of dryinge rate curves. Because any drying rate curve can be transformed into the characteristic function and vice versa, the drying rate can be estimated for various drying conditions from a single drying experiment. Another aoolication is determination of the moisture diffusivity. Using the ‘flux ratio method’ an analytical expression of the characteristic function can be obtained for any aiven moisture diffusivity. The exprcssion enables one to determine the moisture diffusivity for a wide range of moisture content from a single drying experiment.