铸造Fe-C-B合金成分对组织与性能的影响

对Fe-C-B合金的凝固过程与凝固组织特征进行分析.结合相图研究结果,讨论了合金中硬质相种类与形成机理,初步总结了成分对Fe-C-B合金的组织与性能的影响.指出促进和推动Fe-C-B合金的研究与应用,需要在进一步完善Fe-C-B三元相图基础上,深入研究凝固条件、成分对无铬Fe-C-B合金组织与性能的影响,探寻进一步改善其组织与性能的途径.     

Bi(Zn1/2Ti1/2)O3 modified BiFeO3–BaTiO3 lead-free piezoelectric ceramics with high temperature stability

Lead-free high-temperature ceramics with compositions of 0.71BiFe_1−x(Zn_1/2Ti_1/2)_xO₃–0.29BaTiO₃ (BFZTx–BT, x=0–0.05 mol fraction) were fabricated by a conventional solid state reaction method. The effect of Bi(Zn_1/2Ti_1/2)O₃ (BZT) addition on the microstructure, electrical properties, relaxor behavior, and temperature stability has been studied. XRD patterns revealed that all compositions formed a single perovskite phase of pseudo-cubic crystal structure. The grain size was slightly affected by BZT addition. The diffuse phase transition and strong frequency dispersion of dielectric permittivity are observed for BZT modified ceramics. The addition of BZT into BFZTx–BT was also found to affect the piezoelectric properties and temperature stability of the ceramics with maximum values observed for x=0.5% and 1% BFZTx–BT compositions, respectively. The optimum piezoelectric properties with d₃₃=163 pC/N, together with high-temperature stability with a depolarization temperature T_d∼380 °C, reveal the BFZTx–BT ceramics to be promising high-temperature Pb-free piezoelectric materials.     

亚运城水安全与水环境的营造

"岭南水乡,绿色科技"是广州亚运城的规划设计理念之一。本文结合亚运城建设方案,在对水安全和水环境综合评价后,提出亚运城水安全和水环境营造的目标和思路,并从防洪排涝系统、地面高程系统、污水系统、河道水循环、多自然河流建设等方面提出具体的实施方案,以实现建设生态亚运城的目的。     

微机形成的非球面干涉图

介绍一种新的非球面检测方法。用微机技术，对偏离球面很小的非球面作模拟非球面的干涉，获得理想的非球面干涉图。用模拟的理想干涉图作“样板”，使高次非球面的面形在激光球面干涉仪上进行精确测量成为可能。提供了四种类型小非球面度的高次或二次非球面干涉图。给出了几个在CQG一1型激光球面干涉仪上作出的测量结果。其测量精度约为0．5λ。     

装有抗侧翻液压互联悬架校车的动态特性分析

基于牛顿第二定律和传递矩阵法,建立装有抗侧翻液压互联悬架校车全车模型的机液耦合系统动力学方程。完成该非线性系统特征值辨识及模态分析,并对比分析校车安装液压互联悬架前后的动态特性。分析了阻尼阀参数对校车主要模态动态特性关系的影响,结合整车模态匹配策略及阻尼特性需求,提出基于搜索法的阻尼阀参数设计方法,并通过校车动态特性分析验证了该方法的有效性。分析结果表明,抗侧翻液压互联悬架可显著提高车辆的抗侧翻性能,通过合理设计阻尼阀参数可极大改善该耦合系统的阻尼特性。     

A model for performance optimization of wet flue gas desulfurization systems of power plants

In this paper, a model of limestone/gypsum wet flue gas desulfurization (WFGD) system was developed based on unsteady theory. The models of processes of absorption section and oxidation section were developed and incorporated into the WFGD integral model. The sub-model of motion of slurry drops, absorption of SO₂, dissolution of limestone and crystallization of gypsum were included in the model of absorption section, while the model of oxidation section was developed by the population balance theory. The calculation results of the desulfurization system for 300 MW utility in China by this model was compared to that of corresponding measured results. The simulation results agreed with the measurement results very well. The operation mode of boilers of power plant in China is different to that of other countries since variable coal property and unstable loads of boilers. The differences of operation mode lead to the variation of process parameters of WFGD system. The influences of liquid-to-gas ratio, SO₂ concentration of inlet flue gas, and combination mode of different spray levels to the desulfurization efficiency were analyzed. Based on the analysis, some advices of performance optimization of flue gas desulfurization systems in China were suggested.     

Particle‐scale investigation of the solid dispersion and residence properties in a 3‐D spout‐fluid bed

Three‐dimensional modeling of the gas–solid flow in a spout‐fluid bed is conducted at the particle‐scale level. Both the local and systematic dispersion behaviors of solid phase are initially investigated. Then, the solid circulating and resident behaviors are discussed. The results demonstrate that vigorously lateral solid dispersion appears in the spout region and the periphery of the fountain, whereas intensely vertical dispersion exists in the central region of the bed. Moreover, the inlet configuration of bed strongly affects the distribution of lateral dispersion, while its influence on the vertical one disappears in the fountain. Strong anisotropy of solid dispersion along the three directions is obtained. Systematic dispersion intensity along the vertical direction is an order of magnitude larger than the lateral one. In addition, two circulating patterns of solid phase can be identified. Solid residence time is the smallest in the spout region and the largest in the bottom corner. © 2014 American Institute of Chemical Engineers AIChE J, 60: 2788–2804, 2014     

高效建筑砂浆外加剂的性能研究

Ｓ Ｇ 系列高效建筑砂浆外加剂是一种新型的水泥砂浆拌合物外加剂,掺入后不仅能改善建筑砂浆的和易性和保水性,而且能明显提高砂浆的各项性能指标。详细地介绍了掺 Ｓ Ｇ 外加剂建筑砂浆的性能指标,并与未掺外加剂的砂浆作对比。该产品已在多项建筑工程中应用,技术经济效益显著     

大豆凝血素的灭活研究

主要研究了大豆中的抗营养因子之一－－凝血素的灭活方法。凝血素是一种糖蛋白,能使动物中的红血球凝集。分别利用干热处理法,湿热处理法和发芽法来灭活大豆中的凝血素。研究表明：干热处理和发芽处理不能使凝血素活性完丧失,而９５℃,３５ｍｉｎ或１２０℃,１５０ｍｉｎ的湿热处理可以使凝血素活性完全丧失,使之对红细胞不再发生凝集作用。