用MOCVD法制备铁系云母珠光颜料

以Fe(CO) 5为物源 ,在常压喷动流化反应器中 ,以金属有机化学气相沉积 (MOCVD)法对云母粉进行包覆 ,制备铁系 -云母珠光颜料。实验结果表明 :在沉积温度 2 5 0℃ ,氧气流量 3mL·s-1,沉积时间 5min时能得到棕色色泽的珠光颜料 ;随着沉积温度的提高和反应时间的延长 ,可获得红棕、金红、橙红、深红等不同色泽的珠光颜料。用色差仪测定颜料的明度值L 、红度值a 、黄度值b ;X衍射仪表征颜料的表面成分 ;酸滴定计算氧化物的涂覆率。探讨了温度、时间、氧量对珠光颜料表面成分和珠光光泽的影响     

Langmuir吸附方程的应用

本文总结了Langmuir方程在吸附分离过程中的应用。利用Langmuir方程得到直观表达混合气组分气体间吸附强弱关系及分离的难易程度的x-y图，推导了Lewis关系式。     

丁苯胶乳的稳定性研究

简要介绍了丁苯胶乳（SBL）的制备方法，探讨了乳液聚合过程中胶乳稳定的机理，考察了影响胶乳反应稳定性和储存稳定性的主要因素，如：聚合釜搅拌、聚合助剂以及储存条件等，提出了控制方法和注意事项，在工业生产中取得了良好效果。     

Effect of rare earth elements surface treatment on tensile properties of aramid fiber‐reinforced epoxy composites

Solutions of rare earth modifier (RES) and epoxy chloropropane (ECP) grafting modification method were used for the surface treatment of aramid fiber. Tensile properties of both the aramid/epoxy composites and single fibers were tested. The effects of RES concentration on tensile properties of aramid/epoxy composites were investigated in detail to explore an optimum amount of rare earth elements in solution for modifying aramid fiber. The fracture surface morphologies of tensile specimens were observed and analyzed with the aid of SEM. The experimental results show that rare earth treatment is superior to ECP grafting treatment in promoting interfacial adhesion between the aramid fiber and epoxy matrix. Meanwhile, the tensile strengths of single fibers were almost not affected by RES treatment. The optimum performance is obtained when the content of rare earth elements is 0.5 wt %. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1037–1041, 2004     

等离子体条件下煤基富勒烯的制备及生成机理

以淄博贫煤为原料，用射频等离子体法合成碳纳米管（carbon nanotubes，CNTs）和纳米洋葱状富勒烯（nano—structured onion—like fullerenes，NSOFs），运用场发射扫描电子显微镜（FE—SEM）和高分辨透射电子显微镜（HRTEM）对产物进行了表征和分析．结果表明：以淄博贫煤为原料制备出CNTs和NSOFs，CNTs直径分布均匀，约为10nm左右，准球状的NSOFs直径分布在8nm-30nm之间，石墨化程度较高；并对不同变质程度的煤制备富勒烯的生成机理进行了比较与讨论．     

Numerical computation for clustering of carbon particles with various sizes under both natural and magnetizing convections

The behavior of carbon particles from 0.01 to diameters in natural convection flow field of air was numerically studied including the effect of the magnetic field and the Brownian motion. One thousand carbon particles were released randomly in a vertical cylindrical enclosure whose height is equal to its radius. The enclosure was heated from below and cooled from above to produce the bulk flow of the natural convection of air in the atmospheric condition. A coil with electric current was set coaxially at the enclosure bottom to produce a magnetic field. Sample computations are carried out for the enclosure of 3 cm high and maximum magnetic field is 2.8 T or less. The results show that the natural convection of air is enhanced by the magnetic field. With the increase in the magnetic strength, more particles go along the fluid streak lines. With the increase in the particle size, more particles get together at the vortex center and cluster.     

铌酸催化合成乙酸苯乙酯

将铌酸用于催化合成乙酸苯乙酯 ,在醇酸摩尔比 1∶5 ,回流反应 2h ,催化剂用量 (以 1mol醇计 )为 5g的条件下 ,酯收率可达 84 .3%以上。催化剂不经处理 ,可多次循环使用 ,不污染环境 ,相对于一些其他催化剂 ,具有明显的优点。     

近临界水中薯蓣皂苷水解生成薯蓣皂苷元的工艺研究

薯蓣皂苷元是合成甾体激素类药物和甾体避孕药的重要中间体,传统工艺采用盐酸水解法将黄姜中的薯蓣皂苷水解生成薯蓣皂苷元,反应时间4 h,最大收率为1.78%.该工艺反应时间长,耗水量大,对环境污染严重.今研究了无催化剂条件下,近临界水中薯蓣皂苷水解成薯蓣皂苷元的工艺,分别考察了反应温度、反应压力、反应时间等因素对薯蓣皂苷元收率的影响.研究结果表明,近临界水解法工艺简单,反应时间短,对环境友好,在较佳工艺条件下:P=25.0 MPa,T=260℃,t=10 min,薯蓣皂苷元收率为1.46%.     

WATER MIST FLOW IN A SUPERCONDUCTING MAGNET INCLINED AT VARIOUS ANGLES

Water mist (diamagnetic) flow in a superconducting magnet of 10 T at various angles is studied experimentally and numerically. Water mist is produced by ultrasonic atomizers and fed into a cylindrical Plexiglas pipe (inner diameter, 90 mm) placed in a bore space of an inclined superconducting magnet. The water mist is found to stop at some locations in the magnet at inclined angles ψ ≤ π/6. At ψ ≥ π/4, the amount of mist flowing out of the other opening of the pipe increases with an increase in inclined angle. In the computation of this phenomenon, water mist is simulated with 1000 water droplets of 3 μm diameter. Brownian motion is considered and the Langevin equation is solved. The numerical results show that at ψ ≤ π/6, most of the water droplets accumulate above the magnetic coil. However, at ψ ≥ π/4, with an increase in inclined angle, the number of water droplets passing through the magnetic coil increases.     

Effect of particle size on the surface oxidation and flotation behavior of galena particles in lime system

ABSTRACT

In this research, the effect of particle size on the surface oxidation and flotation behavior of galena in the lime system was studied. Coarse (?0.074 + 0.038 mm), intermediate (?0.038 + 0.025 mm) and fine (?0.025 mm) galena particles were used in the experiment. The dissolution tests, flotation tests, and sorption tests were accomplished. Through further analysis by XPS, the effect of particle size and lime was observed. The decrease of mineral particle sizes increased the adsorption ratio of collector and the dissolution of galena, while the hydrophilic product OH^?/Ca(OH)⁺ produced by dissolution occupied the dominant position, which led to the minerals hydrophilic.