我国城镇住宅节地措施研究简

在城镇化的发展过程当中,城市土地价值越来越高,如何通过研究住宅的发展来节约土地资源变得尤为重要.笔者通过对城镇住宅节地措施的研究,分析发展节地住宅环境,希望能对我国节约城镇土地有所帮助.     

基于宏观断面的内饰B面设计

在汽车造型设计中,确保设计师的造型思想能够在工程上得以实现,始终是贯穿在造型设计中的一条主线。本文重点阐述了在B面设计阶段,如何基于宏观断面输入,使得最终发布的B面数据既符合造型要求,又满足各种工程约束的方法及流程。     

沿层中值滤波在消除深拖浅地层剖面电干扰中的应用

声学定位系统的充电会在深拖搭载的浅地层剖面上造成竖条形噪声,严重影响海底地层资料的处理与解释。本文分析了上述电噪声信号特征,采用了中值滤波方法,对其进行了处理。文中设计了水平和沿层位两种不同窗口进行滤波,并改变窗口长度进行了滤波效果比较。实验结果表明,沿层位窗口可以更好地消除噪声并实现信号保真。     

Investigation of thickness and wax content of wax deposits in polyethylene pipe using a flow loop

In this study, the thickness and wax content of wax deposits were found to be thinner and lower in the polyethylene (PE) pipe than in the stainless steel (SS) pipe using a flow loop apparatus. The diffusivity of wax, radial thermal gradient, and wax precipitation rate in the PE and SS pipes were calculated and compared. It was found the diffusivity of wax in the PE pipe was higher and tended to enhance the wax deposition in the PE pipe, while the radial thermal gradient and wax precipitation rate were lower in the PE pipe and had the opposite effects. These factors are shown to be comparable with each other and the effect of the thermal gradient dominates the mass flux of wax from bulk to the oil-deposit interface and into the deposits finally, thus causing differences in thickness and wax content of deposits between the PE and SS pipes.     

Phase equilibria in the La2O3-Y2O3-Nd2O3 system at 1500 °C

The phase equilibria in the ternary La₂O₃-Y₂O₃-Nd₂O₃ system at 1500 °C were studied by X-ray diffraction, petrography, and electron microscopy in the overall concentration range. The samples of different compositions have been prepared from nitrate acid solutions by evaporation, drying, and calcination at 1100 and 1500 °C. The solid solutions based on various polymorphous forms of source components and ordered phase of LaYO₃ were revealed in the system. The isothermal section of the phase diagram for the La₂O₃-Y₂O₃-Nd₂O₃ system has been developed. It was established that in the ternary La₂O₃-Y₂O₃-Nd₂O₃ system there exist fields of solid solutions based on hexagonal (A) and monoclinic (B) modifications of La₂O₃ and Nd₂O₃, cubic (C) modification of Y₂O₃, as well as perovskite-type structure of LaYO₃ (R) with rhombic distortions. The systematic study that covered the whole composition range excluded the formation of new phases. The refined lattice parameter of the unit cell and the boundaries of the homogeneity fields for solid solutions were determined.     

影响薄壁球墨铸铁白口倾向和球墨数量的因素分析

研究了不同的冷却速度、稀土加入量、碳量、硅量、Si／C、Mn／S及孕育处理等工艺时薄壁球墨铸铁球墨数量和白口深度的影响。结果表明，随着冷却速率增加，薄壁球墨铸铁石墨小球越多，但容易产生白口。冷速较大时，加入稀土元素进行孕育和控制碳当量，可以有效的消除薄壁球墨铸铁的白口现象，当Si／C大于0．80、Mn／S大于20时薄壁件白口倾向较小。     

采用辊切轧制提高轧机吃坯能力

为了解决小轧机如何使用大连铸坯的问题，本文提出用辊切轧制的方法。并从轧件受力和不均匀变表两方面分析了辊切变形的机理；讨论了辊切轧制的孔型设计方法、配辊方法和导卫设计方法；分析了采用辊切轧制方法后可能带来的经济效益。     

建立劈分法轧制H型钢异型坯的宽展模型

介绍了劈分法轧制H型钢异型坯的特殊孔型系统及工艺,在充分考虑孔型形状和轧辊压下对宽展的影响的基础上,把腿部宽展和腰部宽展分开来计算,并且针对不同孔型和不同道次给出了相应的宽展计算公式,理论计算与现场数据相符合.     

大断面蠕铁缸盖缩松原因分析及防治

对于大断面柴油机气缸盖,通过采用顶置发热冒口,并配合使用冷铁,能最大发挥冒口作用。对于大型单体气缸盖,可采用平组立浇方式,增强顺序凝固作用,进一步缩小缩松风险。     

Nd-Fe-B三元系相图的研究 Ⅰ.室温等温截面

观察了Nd-Fe-B三元合金铸态与均匀化处理后的金相组织,并进行了微区成分分析和物相鉴定。确定了Nd-Fe-B成分三角在室温下的各个平衡相区,绘制了该三元系在室温下的等温截面相图。