压力式喷雾并流干燥磷酸—铵的粉料物性及其生产的特殊要求

1999年元月,我厂首次启动粉状磷酸一铵生产线,采用南化集团设计院设计的压力式喷雾并流干燥直接出料流程,生产中遇到了一些问题,我们采取了一系措施,生产已比较稳定,现就生产中出现的现象,分析并流干燥磷酸一铵的粉料物性及生产中的特殊要求。     

选择性填充复鞣剂XTF的研制

讨论一种新型氨基树脂鞣剂的合成方法及影响因素;应用试验结果表明：该鞣剂能有效地进行选择性填 充复鞣,成革丰满、弹性好、粒面细致、色泽均匀、颜色鲜艳,而且提高了成革的得革率。     

棒材轧制中的活套控制

介绍了活套控制的原理及特点;分析并阐述了长钢连轧厂采用活套控制系统的工作过程。     

φ550开坯车间一火成材线材技术改造的探讨

介绍了探讨了长钢三轧厂开坯车间半连续式轧机组线材技术改造和实现开坯车间一次成材。     

浅谈质量体系内的分厂如何保持质量体系的有效运行

研究适合分厂质量体系有效运行的途径和万法,突出过程控制、强化六个要素,强化检查监督、健全质量考核。     

A study on optimum insulation thicknesses of external walls in hot summer and cold winter zone of China

The employ of thermal insulation is one of the most effective ways of building energy conservation for cooling and heating. Therefore, the selection of a proper insulation material and the determination of optimum insulation thickness are particularly vital. Four typical cities of Shanghai, Changsha, Shaoguan and Chengdu are selected to represent A, B, C and D subzone of hot summer and cold winter zone in China, respectively. The optimum thicknesses of five insulation materials including expanded polystyrene, extruded polystyrene, foamed polyurethane, perlite and foamed polyvinyl chloride are calculated with a typical residential wall using solar-air cooling and heating degree-days analysis and P₁–P₂ economic model. And then, life cycle total costs, life cycle savings and payback periods are calculated based on life cycle cost analysis. Considering different orientations, surface colors, insulation materials and climates, optimum thicknesses of the five insulations vary from 0.053 to 0.236 m, and the payback periods vary from 1.9 to 4.7 years over a lifetime of 20 years. The maximum life cycle savings are 54.4 $/m² in Shanghai, 54.8 $/m² in Changsha and 41.5 $/m² in Shaoguan (with a deep-colored northeast wall), and 39.0 $/m² in Chengdu (with a light-colored northwest wall). Finally, an approach to analyze economical efficiency of insulation materials is developed, result shows that expanded polystyrene is the most economic insulation material of the five because of the highest life cycle saving and lowest payback period.     

冶金斜齿轮减速器的动态仿真研究

建立了圆柱斜齿轮的六自由度动力学分析模型,通过变量代替推导了无量纲化后的方程,然后采用Runge-Kutta法进行数值求解,在matlab中求解得到了振动位移曲线、振动速度曲线和相平面图。通过分析证明了此动力学模型是正确的。此研究为降低系统振动噪声、提高动态性能提供了理论基础。     

提高转炉散状料称量准确度的实践

本文介绍了三钢炼钢厂散状料称量系统的构成,着重阐述了称重传感器的安装形式和利用PLC联锁延时保护对提高称量准确度的意义.     

DC/DC模块中功率器件的寿命预计方法

模拟开关电源DC/DC模块内部电路为开关电源中的功率器件—垂直导电双扩散MOS(VDMOS)和肖特基二极管(SBD)—提供恒定电应力,并对其施加温度应力进行加速寿命试验。采用恒定电应力温度斜坡法(CETRM),对开关电源中功率器件VDMOS和SBD的可靠性进行评价;对其失效机理一致性进行分析,计算其失效激活能;并在失效机理一致的范围内外推正常使用条件下的寿命,为开关电源整体可靠性评价提供依据。     

三种纵向结构的AlGaN/GaN HFET性能比较

对AlGaN/GaN HFET纵向的常规结构、倒置结构和双异质结进行了研究,结果表明:常规结构的材料生长简单、容易控制,倒置结构的直流性能低于常规结构,而双异质结虽然在材料生长方面较为复杂,但它可以获得较常规结构更为优良的直流特性.