Die wall lubricated warm compacting and sintering behaviors of pre-mixed Fe–Ni–Cu–Mo–C powders

Polytetrafluoroethylene (PTFE) emulsion was used as die wall lubricant. Die wall lubricating warm compacting and sintering behaviors of pre-mixed Fe–2Ni–2Cu–1Mo–1C powders were studied. Results show that green density and spring back effect of pre-mixed powders all gradually increased as the compacting pressure rose. The green density of pre-mixed powder increased with the rise of compacting temperature and then slightly fell, the maximal green density was obtained at 120–140 °C. The degree of effect of warm compaction conditions on green density in turn from big to small followed as compacting pressure, lubrication, compacting temperature, mixing method and compacting speed. Die wall lubrication in combination with warm compaction effectively increased the compact density of pre-mixed powder. Sintered density of pre-mixed Fe–2Ni–2Cu–1Mo–1C material first increased and then fell as the temperatures went up after compacts were sintered at different temperatures for 50 min, but the trends of sintering dilatation were quite the reverse. Sintered density first reduced and then increased with the going on of sintering time at 1300 °C, but the trends of dimension change after sintering were just the reverse.     

电弧螺柱焊机的电路分析

结合具体产品 ,对电弧螺柱焊机电路的组成和功能进行了分析 ,提供了常见故障原因及排除方法     

无机粉体的有机化改性及在橡胶中的应用

研究了用表面活性剂对无机粉体碳酸钙、钛白粉、白炭黑、凹凸棒土进行有机化改性的方法，制备了改性样品，测定了样品的比表面、接触角及在液体石蜡中的粘度等物化性能，还考察了带有反应性基团的新型阳离子表面活性剂（ＣＤＭＡＡＢ）所改性样品对天然橡胶力学性能的影响，结果表明，所述有机化改性是可行的。     

基于双路特征的宫颈细胞核分割

宫颈细胞核的分割问题研究对宫颈癌筛查诊断具有重要意义，但受边缘模糊及存在干扰物影响给分割任务带来了巨大挑战。针对此问题提出一种基于DeepLabV3+网络的细胞核分割方法，首先充分利用主干网络的输出进行多尺度特征融合，并引入注意力机制，构建了细胞团分割模型，以减少背景中干扰物对细胞核分割的影响；基于此设计了融合Transformer与ResNet50的双路特征提取模块，兼顾模型对全局信息的获取及低层上下文特征的敏感度，提高了模型对细胞核与干扰信息的辨别能力。实验结果表明，算法在宫颈细胞核的分割任务中取得了良好的分割效果，均交并比为0.832 9,较DeepLabV3+模型提高了2.33%,且与其他方法相比获得了更优的性能指标。     

Immobilization of polyphenol oxidase on alginate–SiO2 hybrid gel: stability and preliminary applications in the removal of aqueous phenol

An organic/inorganic hybrid gel of alginate–SiO₂ (ALG–SiO₂) was used to immobilize the partially purified potato polyphenol oxidase (PPO) for the treatment of phenolic wastewater. The influences of alginate concentration, quantity of both enzyme and tetramethoxysilane (TMOS) on immobilization were investigated. The Michaelis constant for immobilized PPO was determined as 14.7 mmol L⁻¹ at 25 °C, and the highest activity of immobilized PPO was achieved at pH 7.0. The ALG–SiO₂ immobilized PPO was more stable than the free PPO or ALG(alone) immobilized PPO. This study suggests that ALG–SiO₂ immobilized PPO might be a potential tool for the removal of phenolic compounds from industrial wastewater. Copyright © 2008 Society of Chemical Industry     

试论煤炭工业可持续发展的涵义

对煤炭工业可持续发展定义进行了探讨，认为要准确界定其涵义，目前还面临许多不确定因素．从耗竭时间函数、代际公平配置和社会容忍程度的角度对有关不确定问题进行了分析，并给出了一种定义，研究了它涵盖的具体内容．     

水轮机蜗壳的下料及成形

以钣金下料为基础,采用数学模型的方法,详细介绍水轮机蜗壳的展开下料及采用瓦片压制法压制时如何确定压形线,以确保产品质量符合设计要求.     

Synthesis of needle-like aragonite from limestone in the presence of magnesium chloride

Needle-like aragonite was synthesized with a reversible solution reaction from limestone without calcinations. Scan Electron Microscope (SEM) and X-ray Diffraction (XRD) were used to characterize the morphology and the crystal structure of aragonite. The synthesis of aragonite whisker involves two steps. At first GCC (Ground Calcium Carbonate) was dissolved in an aqueous solution of magnesium chloride with reflux and air flush. Then CO₂ was bubbled into the suspension at a low temperature to produce aragonite whisker. An in-house designed reactor and acid–base titration analysis were used to measure the remaining GCC content in the reaction mixture. A kinetics equation of GCC dissolution was developed, which showed a first-order kinetic feature to magnesium chloride concentration. A reaction rate constant of 0.04234 h^?1 was obtained. The dissolution rate of GCC in magnesium chloride is much higher than that in the magnesium sulfate solution. Some aragonite whiskers with a length of ca. 20 μm and an aspect ratio of 8–12 can be synthesized.     

用现代生物技术改革生酒传统工艺的初探

该文主要探索了寿生酒传统工艺的改革，试验表明：当红曲用量减少40％，用真菌淀粉酶，黄酒活性干酵母取代，所酿制的寿生酒不仅品质更高，而且出酒率提高了5％左右。     

汽机第六段抽汽温度高的原因分析及处理

重点分析广州发电厂4台汽轮机第六段抽汽温度高的原因，并有针对性地进行系统改造，使机组运行的安全性、经济性得到提高。