高效蓄热式工业炉及其应用

阐述了高效蓄热式工业炉（北岛炉）的原理及其应用情况。北岛炉将蓄热回收和换向式燃烧系统与炉子结合于一体，可将空气和煤气同时预热到1000℃，系统排烟温度低于150℃。在轧钢加热炉上应用，可以以纯高炉煤气为燃料，达到节能30％－50％、提高炉内温度均匀性、减少氧化烧损、保护环境的效果。     

Physicochemical aspects of carbothermic reduction of cassiterite in the ionic melt

Conditions of the carbothermic reduction of the cassiterite concentrate in the melt of the Na₂CO₃-NaNO₃ salt system (weight ratio 1: 0.3) are investigated. The charge composition is established, and the temperature range of reduction (600–900°C) is determined. It is shown that the intermediate Na₂SnO₃ compound is formed during the interaction of cassiterite with the melt. This compound is mainly reduced by gaseous CO in a liquid phase of the melt with a high rate (1.5 h), thereby providing the recovery of 97% Sn from the cassiterite concentrate into the crude alloy.     

复式比例阀计算机均衡凝固工艺设计及数值优化

针对天津宝利福有限公司的复式比例阀灰铁铸件,应用制图软件(UG)绘制出三维零件实体图,并辅助进行模数和周界商计算,划分补缩域;以均衡凝固理论为依据进行分析计算,设计计算铸件的冒口、浇注系统及分型面.用数值模拟软件对设计方案进行了校核验证,实际浇注结果表明,设计是合理的.     

土体自重应力计算方法的探讨

依据有效应力原理,论述了地基中存在承压水及有越流情况下有效应力的计算.由此可知,为达到准确计算地基土自重应力的需要,在岩土工程勘察时,不但要量测潜水位,而且应重视对承压水位的测量,避免漏失掉承压水头压力这个重要数据.另外,还应重视编制、绘制承压水分布情况的系列图件,以满足土体自重应力计算方面工作的需要.     

模具专业的《数控加工》任务驱动教学探索

模具专业的《数控加工》课程传统教学模式存在很多不足,教学效果也不理想。为强化学生职业能力,提高就业竞争力,本文提出以模具加工生产实例为数控加工课程教学单元,从学习目标驱动与生产任务驱动两方面运用任务驱动教学方法进行了尝试与探索。     

高性能钢-高强混凝土组合梁抗弯承载力研究

以高性能钢HPS485W、HPS690W及高强混凝土C60、C70为主要研究材料,对高性能钢-高强混凝土组合梁进行弹性和塑性分析;通过简支组合梁的实例,分别计算各组不同截面不同材料组合梁的屈服弯矩和极限弯矩,发现高性能钢-高强混凝土组合梁的抗弯承载力比普通组合梁大大提高;另外运用有限元软件ANSYS模拟上述实例中的各组组合梁,并将有限元数值模拟结果与理论计算结果相比较,以验证其正确性和合理性。     

创意纷呈的东京创意市集博览会Tomoko的时尚日记(八)

Design Festa是一个没有边界的艺术盛会．它超越了年龄和国界。此时的东京就像一个充满了大量艺术和时尚产品的胃，虽然它依旧难以令所有人满意．但你很难再找到超越它的艺术博览会了。[编者按]     

布拉维法则和剪式合成法与高品级金刚石

讨论两种与高品级金刚石有关指导思想。似乎是些纯基础理论的内容,但绝非如此,它是指导我们一些基本思路的方法。     

Effect of molecular weight on crystallization of semirigid poly(phenylene sulfide) under shear flow

Isothermal crystallization of poly(phenylene sulfide) with three molecular weights (M_w = 22k, 48k, and 52k, respectively) under shear condition has been investigated. It appears that shear can induce all these three PPS samples to form a thread‐like crystal structure which consists of the numerous stable nuclei that align tightly in the direction of shear. Crystallization kinetics of PPS has been greatly influenced by shear flow. Higher shear rate and long shear time can lead to decrease of spherulite growth rate of PPS. Also, the spherulite growth rate of PPS is affected by supercoolings and molecular weight. For the lower molecular weight (M_w = 22k), the spherulite growth rate is independent on the shear rate and shear time; while for the higher ones (M_w = 48k and 52k), with the increasing of shear rate, the spherulite growth rate of PPS increases to reach maximum at first, and then decreases. The lower the crystallization temperature is, the more the spherulite growth rate changes, showing that higher orientation of molecular chains can be obtained more easily with increased supercooling. A model has been proposed to explain the mechanism of thread‐like crystal formation under shear flow. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012