广西某锑锌银钨多金属矿选矿工艺研究

经过全面详细的工艺矿物学研究和选矿试验研究,针对广西某锑锌银钨多金属矿的矿石特点,提出了"先浮辉锑矿—后浮铁闪锌矿—再浮白钨矿—白钨粗精矿加温精选—浮选尾矿重选回收黑钨矿"的合理工艺流程,锑锌银钨均得到较好回收。     

Oil Binding Ability of Chlorinated and Heated Wheat Starch Granules and Their Use in Breadmaking and Pancake Baking

Chlorination and heat treatment of wheat flour changes the surface character of starch granules from hydrophilic to hydrophobic, and high oil binding ability of the starch granules can be observed. It was suggested that the hydrophobicity, in case of chlorination, was due to chemical modification of the starch granule surface proteins, and, in case of heat treatment, due to conformational changes of the proteins. This hydrophobicity could be also obtained by aging (233 days at room temperature). The hydrophobicity of starch granules in batter is highly related to the springiness of pancake. Heat treated wheat starch granules can encapsulate flavor through their oil binding ability.     

Effect of channel length on critical heat flux under conditions of high subcooling and high velocity in short heated channels

The characteristics of critical heat flux (CHF) in existing experiments under high subcooling and high velocity in short heated channels have, for the first time, been systematically and quantitatively investigated to provide a CHF correlation that can properly predict the effect of channel length, especially when the channel length-to-channel diameter ratio L/D is less than about 20. The major test conditions of existing CHF experiments investigated in this study were channel diameter 1 to 4 mm, L/D 1 to 25, 0.1 to 1.2 MPa pressure, 34 to 117°C inlet water subcooling and 500 to 40 700 kg/(m² · s) mass flux in circular channels, and 3 to 20 mm gap size, 6 to 40 L/D_e, 0.1 to 3.1 MPa pressure, 4 to 166°C inlet water subcooling, and 940 to 27,000 kg/(m² · s) mass flux in rectangular channels. The effect of L/D on CHF was evaluated referring to the analytical solution of CHF, which was previously derived by the author for the channel flow at high subcooling and high velocity. As a result, the effect of L/D was quantitatively clarified as an effect of magnitude in heat transfer of single-phase forced-convection flow, giving a larger CHF with a smaller L/D in the case of L/D less than about 20. The proposed correlation predicts CHF to within a ±35 percent error margin. ©1998 Scripta Technica, Heat Trans Jpn Res, 27(7): 509–521, 1998     

Investigation of Dry‐Heated Hard and Soft Wheat Flour

The Amylograph profile of dry‐heated (120°C, 120 min) wheat flour showed a drastic change, i.e. an earlier onset time and higher peak viscosity than that of a control. However, no difference in the size of the starch granules was observed between dry‐heated and normal starch at every temperature. Wheat flour was fractionated with acetic acid, and the separated prime starch (PS) and tailings (T) fractions were dry‐heated at 120°C for 30, 60, 90, and 120 min, respectively. There was almost no difference in the RVA and DSC profiles between PS and dry‐heated PS, and T and dry‐heated T fractions, i.e., dry heating of wheat flour did not change the structures of starch that would be related to onset time and peak viscosity in the Amylograph profile. We thus excluded the water solubles (WS) fractions from control and dry‐heated wheat flour, but the effect of dry heating on the Amylograph profile was not lost. Next, the gluten (G) fraction was excluded following WS fraction from these wheat flours, and Amylograph tests were performed. The Amylograph profiles in both wheat flours were almost coincidental, which showed that the G fraction in dry‐heated wheat flour caused the earlier onset time and higher peak viscosity.     

自生复合Cu-Cr合金定向凝固新方法

简述了高强度高导电性铜合金的制备方法．指出,基于热型连铸工艺制备具有定向凝固组织的Cu-Cr合金自生复合材料由于充分利用铜基体的导电和第二相Cr纤维强化的作用,因而具有比较好的综合性能,具有广阔的应用前景．     

An unsteady flow structure on a heated rotating disk under mixed convection

A flow field under mixed convection on a heated rotating disk has been measured using an ultrasonic velocity profiler (UVP). The measured velocity field is a spatio‐temporal one as a function of radial coordinates and time. The objective of this paper is to clarify the vortex structure caused by the instability between buoyancy and centrifugal force. The vortex appears under typical conditions of Reynolds numbers and Grashof numbers and it moves toward the outside of the disk. This behavior can be classified into two patterns. The size of the vortex structure decreases with an increasing Reynolds number and increases with the Grashof number. The traveling velocity of the vortex increases with the Grashof number. Moreover, it decreases with an increasing Reynolds number in spite of increasing centrifugal force. According to these results, the region dominated by natural, forced, and mixed convection is classified in the relationship between Reynolds and Grashof numbers. © 2005 Wiley Periodicals, Inc. Heat Trans Asian Res, 34(6): 407–418, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20074     

氧化硅亚微米纳米线光波导的制备

介绍一种新的氧化硅亚微米纳米线光波导的制备方法。使用这种方法制备出的光波导具有良好的直径均匀性和表面粗糙度,满足低损耗传输的要求。纳米级的尺寸以及独特的光学特性,使得亚微米纳米线光波导在亚波长结构的微电子、光电子及光子器件中具有较好的应用前景。     

炉水循环泵马达腔冷却水温度升高的原因分析及预防措施

根据某电厂提出我公司超临界660MW锅炉的启动循环泵马达腔冷却水温度升高的问题,给出了炉水循环泵的结构及产生问题的原因分析.     

热载气体直接加热石油烃裂解研究进展?II.裂解工艺流程

概述了以气体为热载体的石油烃直接加热裂解的主要工艺,分析对比了各裂解工艺的组成、运行条件、产物产率等技术经济指标,分别论述了其技术改进及发展状况. 指出热载气体直接加热裂解工艺具有原料适用性广、产物分布灵活、热效率较高和受结焦影响小等优点,但同时也有运行时间短、缺乏系统性研究数据等不足;并对热载气体直接加热石油烃裂解的研究前景进行了展望,指出以氢氧燃烧产生的过热水蒸汽作为热载气体的直接加热裂解工艺技术,在提高换热效率、降低碳排放、连续除焦等方面有很大发展空间,尤其在扩大裂解原料范围、提高烯烃产率方面具有广阔前景.