THE RELATIONSHIP BETWEEN HAZE AND THE SIZE OF PARTICLES IN BEER

Haze measurements have been obtained for suspensions of polystyrenelatex particles of known diameter using two light scattering instruments which measure at angles of 90° and 13° respectively. The results agree well with the theory of light scattering and demonstrate the significant effects of particle size and angle of detection upon the instrumental values for haze. This information has been used to correlate the particle size distributions of a number of beers, as measured by Coulter Counter, with the corresponding, measured haze values.     

交联型聚醚聚氨酯的表征、力学性能及其碱金属盐络合物的导电性能

采用三羟甲基丙烷（ＴＭＰ）作交联剂与聚乙二醇（ＰＥＯ－１５４０）和甲苯二异氰酸酯（ＴＤＩ）反应，得到了具有较好力学性能的交联型聚醚聚氨酯（ＰＥＵ），该聚合物与ＬｉＣｌＯ４的结合物具有较高的室温电导率（σ３０℃＝１．８７×１０￣（－４）Ｓ／ｃｍ）。采用全反射红外光谱（ＡＴＲ－ＩＲ）对聚合物的结构进行了表征。对聚合物的组成、不同ＴＤＩ类型及络合盐浓度对聚合物力学性能及其络合物电导率的影响进行了探讨。低度交联聚合物的络合物，其电导率与温度的关系符合建立在自由体积理论上的ＶＴＦ方程，表明络合物中离子的传导主要是在无定形区域进行，与自由体积有关。     

压力对Fe－29wt％Ni合金超细微粒特性的影响

利用蒸发冷凝法，制备了不同平均粒径的Ｆｅ－２９ｗｔ％Ｎｉ合金超细微粒。在不同压强下，将超细微粒压制成片。随压强增大，马氏体体积分数和比饱和磁化强度σｓ明显增大，而矫顽力Ｈｃ呈线性下降。压力效应与平均粒径ｄ大小密切相关     

Energy Dissipation at the Slug Nose and the Modeling of Solids Transport in Intermittent Flow

It is shown, by means of Lagrangian momentum and power balances across the slug nose in slug flow, that the power dissipated due to sudden expansion of the fluid in the film immediately downstream of the slug nose is greater than the power lost due to viscous action at the pipe wall but that it may not be large enough to materially aid particle transport. This has the implication that sand transport in intermittent flow may be considered as transport in a hybrid flow of hydraulic conveying and stratified flow when the length of the mixing section at the slug nose is short compared to the length of the slug body.     

结构陶瓷的空蚀性研究

利用转盘装置测量了ZrO2、Si3N4和Al2O3／Ti(NC)等陶瓷材料受到水的空蚀破坏的体积损失,通过SEM观察和XRD分析,探讨了微观结构和抗空蚀性能的关系。     

水平管气力输送数值模拟

本文采用粒子追踪理论对水平管中粒子流动状态进行了数值模拟.文中提出了一种新的粒子碰撞模型,并忽略粒子的旋转和扬力,仅考虑气流阻力和重力对粒子的影响,在输送量为9.13×10~3kg/s,混合比约0.3的条件下,通过数值计算得知:由于粒子间的碰撞,使得异径粒子的速度趋向平均化;粒子间的碰撞是粒子悬浮的原因之一;粒子的浓度沿管轴向是随时间而发生变化的.     

Luminescence Characterization of Mg Doped Y2O2S:Ti Long Afterglow Phosphor

Y1.94-xMgxO2S:0.06Ti (0≤x≤0.10) phosphors with long afterglow were synthesized by solid state reaction route. The photoluminescence spectra, decay curves, thermoluminescent spectra and chromaticity coordinate curves were investigated. The results show that the luminescence intensity of Y1.94-xMgxO2S:0.06Ti (0≤x≤0.10) phosphors decrease gradually with increasing Mg2 ion content, and the shape of luminescence spectra and chromaticity coordinate change as well. Furthermore, two thermoluminescent peaks in single Ti-doped Y2O2S sample are found at 91.8 and 221.5 ℃, respectively. Nevertheless, significant different spectra were found for the Mg, Ti co-doped Y2O2S samples that three thermoluminescence peaks appear at 52.3, 141.7 and 226.8 ℃, respectively. These results indicate that the co-doped Mg ion changes the inherent trap depth of single Ti-doped Y2O2S:Ti phosphor, and induces simultaneously a new trap level in the Y1.94-xMgxO2S:0.06Ti phosphor. Based on the analysis of thermoluminescent spectra, photoluminescent spectra, decay curve and crystal structure defect, it was proposed that the varied structure defect and introduced new trap level by the doped Mg2 ions should be responsible for reducing luminescence intensity and varying color in the Y1.94-xMgxO2S:0.06Ti phosphor.     

Kinetic investigation of the carbothermal reduction of an Iranian clay

The kinetics of the carbothermal reduction of clay under argon atmosphere has been investigated by the X-ray diffraction method. The clay-carbon (excess) mixture was formed into 2 cm diameter disks of different thicknesses. Experimental data evidences the significant effect of sample thickness on the reaction rate at 1400 °C. Decreasing thickness promotes mullite dissociation and formation of SiC and alumina powders. Mathematical modeling of the reaction system showed the gas diffusion in the Knudsen regime through the pellet to be the rate controlling step. Diffusivity of CO and reacted core tortuosity factor have been calculated.     

四倍频Nd：YAG激光在高压氢气中的喇曼频移研究

利用Nd:YAG固体激光器四倍频输出(266nm)在高压H₂中的受激喇曼散射获得多波长的激光输出。当泵浦能量一定时,通过改变H₂压力得到了最佳的能量输出,299nm波长的激光能量为3mJ,341nm波长的激光能量输出为6.1mJ,398nm波长的激光能量输出为2.8mJ,239nm波长的激光能量输出为0.8mJ,同时在477nm,595nm,218nm,200nm波段也有能量输出。     

The Problem of Estimating the Uncertainty of the Fixed Point Temperature Due to the Presence of Impurities

The main problems in estimating the uncertainty due to the presence of impurities in the material: the absence in the documents of a unique definition of the quantity being measured – the fixed point temperature, the lack of agreed methods of realizing the fixed points and the insufficient justification of the equations used for the estimate, are analyzed. The results of a measurement of the melting point of gallium are presented, which differ in the conditions in which they were realized – with one and two liquid-solid interfaces and different solidification conditions, are presented. The reasons for the considerable difference between the values of the temperatures obtained in these experiments are discussed.