材料期刊网

Shift From Coke to Coal Using Direct Reduction Method and Challenges

Okonkwo Paul Chukwuleke , CAI Jiuju , Sam Chukwujekwu , XIAO Song

钢铁研究学报(英文版)

Ironmaking involves the separation of iron ores. It not only represents the first step in steelmaking but also is the most capitalintensive and energyintensive process in the production of steel. The main route for producing iron for steelmaking is to use the blast furnace, which uses metallurgical coke as the reductant. Concerns over the limited resources, the high cost of coking coals, and the environmental impacts of coking and sinter plants have driven steelmakers to develop alternative ironmaking processes that can use noncoking coals to reduce iron ores directly. Since the efficiency and productivity of modern large capacity blast furnaces will be difficult to surpass, blast furnaces will continue to retain their predominant position as the foremost ironmaking process for some time to come. The alternative ironmaking processes are therefore expected to play an increasingly significant role in the iron and steel industry, especially in meeting the needs of smallsized local and regional markets. It is likely that the importance of direct reduced iron (DRI) and hot metal as sources of virgin iron will continue to increase, especially in the developing countries where steelmaking is, and will be, primarily based on electric arc furnace (EAF) minimills. Consequently, the challenges that are faced by the new technology have to be embraced.

关键词: ironbearing material;coke;flux;coal;blast furnace;sintering;iron ore

Paul阱中射频源倍频作用下囚禁离子运动特性

陈图淼 , 聂宗秀

量子电子学报 doi:10.3969/j.issn.1007-5461.2003.01.010

基于以前的研究结果,采用函数级数展开法,研究了Paul阱中在非理想射频囚禁场作用下、考虑二次谐波φ=U-V1cosΩt-Vscos 2Ωt时囚禁离子运动特性,得到了单个囚禁离子运动Mathieu方程的解析解和z方向离子运动的特征频率(宏运动,微运动)随倍频参数的变化规律.

关键词: 运动特性 , 倍频效应 , Paul阱

Paul阱中共线两离子量子力学问题

邬云文 , 海文华

量子电子学报 doi:10.3969/j.issn.1007-5461.2006.05.011

运用熟知的级数截断方法,设计程序计算了线性Paul阱中两离子量子门系统Schr(o)dinger方程的精确解,分析了质心波函数几个较低能级的态,并作出对应的几率分布图;计算相对距离的方均差△r2＞(h)/2,相对运动的动量方均差△p2＜(h)/2,并满足量子力学的Heisenberg不确定度关系△r.△p＞(h)/2,它满足压缩态的条件,即质心处于基态时,两离子相对位置的量子态是一个压缩态,并得到了两离子纠缠态的表达式.纠缠的存在对量子计算和量子信息有影响,量子测量的不确定度和纠缠是在实验中应加以考虑的问题.

关键词: 量子信息 , Paul阱 , 两离子 , 纠缠 , 量子态

激光冷却Paul势阱中两个粒子的暂态行为

沈京玲 , 戴建华 , 张洪钧

量子电子学报 doi:10.3969/j.issn.1007-5461.2000.05.049

关键词:

PPC/PBS共混体系的粘弹特性

陈君 , 蒋霞 , 陈庆华 , 钱庆荣 , 黄宝铨 , 刘欣萍 , 许兢 , 肖荔人

高分子材料科学与工程

用熔融共混法制备了聚碳酸亚丙酯(PPC)/聚丁二酸丁二醇酯(PBS)共混材料,并采用流变学方法对所制备的共混体系的粘弹特性进行了深入研究.结果表明,PPC/PBS为典型的热力学不相容体系,PBS的加入提高了PPC的加工性能;当PBS的质量分数约为40％～50％时,体系发生相反转,这与Paul模型对相反转点预测的结果一致;在相分离区,动态模量偏离了经典的低频末端标度规则,Han图表现出不同于均相体系的特征,引起时温叠加原理失效;与Gramspacher-Meissner模型相比,Palierne模型可以较好地描述PPC/PBS体系的线性粘弹行为.

关键词: 聚碳酸亚丙酯 , 聚丁二酸丁二醇酯 , 相反转 , 粘弹特性

铟离子冷却用跃迁频率与同位素移动的精密测量

王延辉 , Dumke R , 张洁 , 刘涛 , Stejskal A , 赵燕宁 , 陆泽晃 , 王力军 , 董太乾

量子电子学报 doi:10.3969/j.issn.1007-5461.2008.02.001

利用囚禁在Paul型离子阱中的铟单离子和飞秒光频梳实现了铟离子5s2 1So(F=9/2)-5s5p 3P1(F=11/2)230.6 nm冷却用跃迁频率的精密测量,准确度有超过两个量级的提高.一台基于半导体激光器的四倍频系统作为光源,飞秒激光光频梳作为光频测量的工具,它的参考源为一台铯原子钟.铟离子,'115In+与113In+的跃迁频率分别为1 299 648 954.54(10)MHz和1 299 649 585.36(16)MHz.该跃迁对应的纯同位素移动为630.82(19)MHz,考虑超精细相互作用后,同位素移动为695.76(1.68)MHz.

关键词: 光谱学 , 同位素移动 , 光频测量 , 单离子