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1.
Measurement of oil volume fraction and velocity distributions in vertical oil-in-water flows using ERT and a local probe 总被引：2，自引：0，他引：2
INTRODUCTION The need for metering multiphase flow in the petroleum industry has been evident for many years. Considerable research has been conducted into this field for developing a suitable flowmeter which can be used in industrial environments. Various tech- nologies have been employed, and among which the tomographic techniques are increasingly being used. Process tomography is an emerging measure- ment technology with applications in a broad range of industries. It is non-invasive a… 相似文献
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基于文献含油制冷剂R600a两相流动摩擦压降实验数据,采用文献中6种关联式模型对含油制冷剂R600a两相摩擦压降的实验数据进行预测判断。结果表明:油影响因子模型Schlager关联式和Eckel关联式的预测值与实验值平均绝对偏差分别为27.3%和24.4%;混合物性的两相增强因子模型Zurcher关联式和Hu关联式的预测值与实验值的平均绝对偏差分别为33.8%和34.0%,上述关联式预测值普遍低于实验值。 相似文献
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千山侧柏叶挥发性化学成分分析 总被引：7，自引：0，他引：7
报道了用水蒸气蒸馏-萃取法提取千山侧柏叶中挥发性物质，测得提取的千山侧柏叶挥发油含量为2.0％。用GC／MS法从千山侧柏叶挥发油中分离并确定出30种化学成分，占总挥发油总检出量的98．67％．用峰面积归—化法通过化学工作站数据处理系统，得出各化学成分在挥发油中的相对百分含量． 相似文献
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在输送压力可达4.0MPa,固气比高达450kg/m3的高压气力输送试验台上,用氮气进行粉煤高压浓相气力输送试验研究.分别在不同的输送差压、煤粉湿度、浓度和速度等条件下进行了输送试验,考察操作参数对煤粉固气比等气力输送特征参数的影响,用信息熵分析试验过程中采集到的压力波动时间序列,探讨流动稳定性和流型变迁过程中信息化趋势,建立信息熵和流型之间的关系.结果表明:在输送差压增大的过程中,固气比和Shannon信息熵均增大;气体流量与Shannon信息熵和固气比之间呈现较好的规律性;不同流动形态的Shannon熵差异较大,不同流型之间的Shannon熵区分度较好.随着煤粉湿度的增大,煤粉质量流量和Shannon熵均降低.Shannon信息熵分析为研究高压浓相气力输送流型、流动稳定性及其转变特性提供了一种行之有效的方法. 相似文献
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DMF与CHCl_3混合液精馏分离工艺的研究 总被引：1，自引：0，他引：1
采用模拟的二甲基甲酰胺(DMF)与三氯甲烷(CHCl3)混合液(DMF质量分数为47%),通过精馏塔进行分离。当进料量为2L·h-1时,得出最佳的操作条件如下:进料状态为泡点进料,加料位置为第七块塔板进料,回流比为4。最终结果为:理论塔板数为4.5块,塔板效率为37.5%,塔顶产品DMF质量分数低于0.01%,塔底产品DMF质量分数达到96.03%。该新方法与传统的直接精馏法相比既能减少精馏能耗,又能回收利用DMF,还可使萃取剂CHCl3重复使用,对环境友好不造成污染。 相似文献
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Based on the momentum conservation approach, a theoretical model was developed to predict the superficial liquid velocity, and a correlation equation was established to calculate the gas holdup of an annular external- loop airlift reactor(AELAR)in the bubble flow and developing slug flow pattern. Experiments were performed by using tap-water and silicone oil with the viscosity of 2.0 mm2/s(2cs-SiO)and 5.0 mm2/s(5cs-SiO)as liquid phases. The effects of liquid viscosity and flow pattern on the AELAR performance were investigated. The predictions of the proposed model were in good agreement with the experimental results of the AELAR. In addition, the comparison of the experimental results shows that the proposed model has good accuracy and could be used to predict the gas holdup and liquid velocity of an AELAR operating in bubble and developing flow pattern. 相似文献
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We prepared an SbSn intermetallic compound powder with a mixture of equal molar amounts of antimony （Sb） and tin （Sn） by melt-annealing and high-energy ball milling, and characterized the obtained substance with XRD （X-ray diffraction）, DSC （differential scanning calorimetry）, SEM （scanning electron microscopy）, and XPS （X-ray photoelectron spectroscopy）. The prepared SbSn has a hexagonal structure with a melting point of 425 ℃. The particles have a dendritic appearance in micromorphology images. More Sb atoms are enriched on the surface than Sn atoms. A desulfurization efficiency of up to 33.92% can be obtained when applying this powder as a medium in the electric desulfurization of crude oil under the following conditions an emulsion with a volumetric ratio of water to oil at 20：80, a surfactant mass fraction in the emulsion of 0.18%, a processing time of 17 h, and a voltage of 9.68 V. SbSn could be a promising catalyst for desulfurizing crude oil. The desulfurization performance is ascribed to the electron cavities formed by current induction. 相似文献
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采用微波消解-氢化物原子荧光法测定烟草中痕量砷:空心阴极灯电流130 mA,开启高强度模式,检测器电压为320 V,载气与保护气流速分别为200、700 mL/min,添加硫脲-抗坏血酸预还原样品中的As5+,方法检出限为0.034 ng/mL,线性相关系数为0.999。测试4种市售香烟,测试变异系数为1.34%~4.55%,加标回收率97.7%~100.2%,方法适用于烟草中砷的测定。 相似文献
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抗病毒草药金银花的化学成分分析 总被引：11，自引：0，他引：11
报道了用蒸馏—萃取法提取金银花中挥发性物质，测得金银花挥发油的含量为2．52％，用GC／MS法从金银花挥发油中分离并确定出50种化学成分。用峰面积归一化法通过化学工作站数据处理系统，得出各化学成分在挥发油中的相对百分含量。其中主要成分为酸类化合物占挥发油总量的59．76％，其次为酮类化合物占15．58％，醇类化合物占12．85％，萜类化合物占1．57％，萜类氧化物占1．32％，醛类化合物占1．74％，烷烃化合物占7．18％，共占金银花中挥发油总量的98．44％。 相似文献
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A homogeneous theoretical model is developed to predict the performance of R22 and R290 in adiabatic capillary tubes. The model is based on conservation equations of mass, momentum and energy. Metastable both liquid and two-phase flow regions are considered in the model. In metastable two-phase region, superheated liquid is introduced into the metastable mixture viscosity and two methods are presented to evaluate it. The model is validated by comparing the predicted pressure and temperature profile and mass flow rate with several investigators′ experimental data of R22 and one of its alternatives R290 reported in literature. All of the predicted mass flow rates are within ±8% of measured values. Comparisons are also made between the present model and other investigators′ models or sizing correlation. The model can be used for design or simulation calculation of adiabatic capillary tubes. 相似文献
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INTRODUCTION Measurement technology for gas-solid two phase flow has important applications in fields such as process measurement, forecast and control in in- dustry (Teng et al., 2002). At present, most optical measurement methods, such as LDV (Laser Doppler Velocimetry), Laser Dust Particles Measurement Device, use an optical sensor probe that only yields information on a single point or a partial area in the flow field and cannot yield instantaneous multi-ori- entation flow states.… 相似文献
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UHV／CVD生长SiGe／Si材料分析及应用研究 总被引：1，自引：1，他引：0
以Si2H6和GeH4为生长气源,采用UHV／CVD系统在Si（100）衬底上生长了Sil—xGex合金和Sil—xGex／Si多量子阱结构。采用X射线双晶衍射仪、扫描电子显微镜和原子力显微镜等仪器设备对样品的组份、界面和表面形貌等晶体质量进行了研究。SiGe合金中Si和Ge摩尔分数的比值随着Si2H6和GeH4流量比的增加按比例线性增加,比例因子为2．57。生长的Si0．88Ge0．12合金样品的界面清晰,表面平整,平均粗糙度仅为0．4nm,位错密度低于104／cm2。六周期Si0．88Ge0．12／Si多量子阱的X射线双晶衍射摇摆曲线中存在多级卫星峰和Pendellosung条纹。这些结果表明SiGe合金和SiGe／Si多量子阱均具有很好的晶体质量。 相似文献
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建立固相萃取与UPLC—MS／MS检测食品中黄曲霉毒素M1和黄曲霉毒素B1的方法。样品经乙腈提取和SPE小柱萃取净化,提取液经氮气吹干后,用50％甲醇水溶液定容。超高效液相色谱一串联质谱（UPLC—MS／MS）测定,采用电喷雾正离子（ESI＋）模式电离,多反应监测（MRM）模式检测。流动相为0．1％甲酸水溶液和甲醇,流速0．4ml／min,使用ZORBAX Eclipse XDB—C18色谱柱（100mm×3．0mm×1．8μm）为分析柱。黄曲霉毒素AFM1在0．1～50μg／kg范围内线性关系良好、黄曲霉毒素AFB1在0．1～10ug／kg范围内线性关系良好,相关系数均大于0．999;回收率在83．75％～97．8％之间;检出限AFMl为0．05μg／kg、AFBl0．02μg／kg。该法具有分析速度快,检测准确、灵敏度和回收率高等优点,适合食品中黄曲霉毒素M1、B1含量的检测。 相似文献
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环棱褐孔菌挥发性化学成分的分析 总被引：1，自引：0，他引：1
报道了用同时蒸馏-萃取装置提取环棱褐孔菌的挥发性物质，测得环棱褐孔菌挥发油的含量为5．06％，用GC／MS法从环棱褐孔菌挥发油中分离并确定出21种化学成分．用峰面积归一化法通过化学工作站数据处理系统，得出各化学成分在挥发油中的相对百分含量． 相似文献
18.
RH和RH-KTB精炼过程中钢液流动和混合特性的研究 总被引：7，自引：0，他引：7
The flow and mixing characteristics of molten steel during the vacuum circulation refining,including RH(Ruhrstahl-Heraeus) and RH-KTB(Ruhrastahl-Heraeus-Kawasaki top blowing) processes,were investigated on a 1/5 linear scale water model of a 90t multifunction RH degasser,The circulation rate was directly and more accurately determined,using a new method by which the more reliable results can be obtained.The fluid flow pattern and flow field in the ladle were demonstrated,observed and analyzed.The mixing time of liquid in the ladle was measured using electrical conductivity method.The residence time distribution in the RH model was obtained by tracer response technique.The influence of the main technological and geometric factors,including the gas top blowing*(KTB) operation,was examined.The results indicated that the circulation rate of molten steel in the RH degasser can be fairly precisely calculated by the formula:Q1p=0.0333Qg^0.26Du^0.69Dd^0.80(t/min),where Qg-the lifting gas flow rate(NL/min);Du and Dd-the inner diameters of the up and down-snorkels(cm),respectively.The maximum value of circulation rate of molten steel in the case of the 30cm diameters either of the up-and down-snorkels for the RH degasser(the “Saturated” rate) is approximately 31 t/min.the corresponding gas flow rate is 900NL/min.Blowing gas into the vacuum chamber through the top lance like KTB operation does not markedly influence the circulatory flow and mixing charateristics of the RH process under the conditions of the present work.There exist a major loop and a large number of small vortices and eddies in the ladle during the RH refining process.A liquidliquid two-phase flow is formed between the descnding stream from the down-snorkel and the liquid around the stream.All of these flow situation and pattern will strongly influence and determine the mixing and mass transfer in the ladle during the refining.The correlation between the mixing time and the stirring energy density is τmε^0.50 for the RH degasser.The mixing time rapidly shortens with an increase in the lifting gas flowrate.At a same gas flow rate,the mixing times with the up-and down-snorkel diameters either of 6 and 7cm are essentially same.The 30cm diameters either of the up-and down-snorkels for the RH degasser would be reasonalble.The concentration-time curve showed that three circulation cycles are at least needed for complete mixing of the liquid steel in the RH degasser. 相似文献
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雷玉勇 《重庆大学学报(英文版)》2003,2(1)
1. Introduction With the development of transportation, more and more road tunnels, especially the long tunnels, such as Erlangshan Tunnel (4176 m, China), Arlberg Tunnel (13972 m, Austria), Kan-etsu Tunnel (11055 m, South tube, Japan) and Laerdal Tunnel (24510m, Norway) have been built on the highway lines [1]. In a road tunnel, the exhaust gases given off by automobile engines, such as smoke, carbon monoxide (CO), oxynitride (NOx), hydrocarbon, etc., and dust produced by the passing a… 相似文献
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戴必胜 《黄冈师范学院学报》2006,26(6):63-68
用三唑酮(6.25%) 乙蒜素(93.75%)混合配制成160 m g/L至1 600 m g/L不同浓度的药剂(10种),对九重葛插穗浸泡处理3 h后扦插。实验结果,各种处理中最佳的插穗生根数、根长、根径的平均值分别为23.2根、20.5 mm、1.1 mm,最高成活率达到86.7%,所测生长指标与对照组的差异极显著(P<0.01)。在160 m g/L至400 m g/L范围,药剂的处理浓度与插穗的生根数、根长、根径以及成活率的关系均符合二次曲线模型(R2>0.98),而与枝叶的生长呈负相关(R2>0.95),但与对照的差异不显著。统计分析结果,三唑酮.乙蒜素混剂对九重葛插穗的最佳处理剂量为266 m g/L。 相似文献