低负荷维氏硬度法的负荷选择

本文按照维氏硬度测定的技术条件,将基本公式H_v=1854P/D~2加以变换,从而得到一些较为简单的数学关系式.利用这些关系式,可以对不同金属薄带材料,很容易计算出较合理的负荷大小,既能保证不被"打穿",也使视场内有一个适合观测的压痕图象.     

RFID技术在智能交通管理中应用

本文主要介绍RFDI技术定义及系统工作原理,并重点关注RFID技术在智能交通领域的实际应用方式。同时RFID技术也成功解决了车辆自动识别和信息采集问题,为智能交通管理和服务系统的建立提供了强大的信息支撑和保障。     

Site occupations and ordering behaviour of O phase in Ti2AlNb—based intermetallics

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Characterization of ultrafine La x Sr1−x MnO3 powder prepared by spray pyrolysis

The characterization of La _x Sr_1−x MnO₃ powders produced by spray pyrolysis using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observation, specific surface area (Brunauer-Emett-Teller), and particle size distribution measurements shows that the resultant large particles are loose agglomerates consisting of many small particles. However, the sintered tiny particles can form hard agglomerates, and the particle size increases remarkably. The structures of the powders before and after sintering were identified by x-ray diffraction (XRD). The study of the electrical property of the powder shows that the powder is a metallic conductor. In a reducing atmosphere, the powder can be decomposed. When the powder is cofired with yttria-stabilized zirconia 5% (YSZ) powder at 1200 °C for 5 h, no new phase is produced, and the powder remains a single provskite hexagonal-rhombohedral structure.     

Effect of surface free energy on the adhesion of biofouling and crystalline fouling

Pipelines and heat exchangers using seawater as coolant suffer from biofouling. Biofouling not only reduces heat transfer performance significantly, but also causes considerable pressure drop, calling for higher pumping requirements. It would be much more desirable if surfaces with an inherently lower stickability for biofouling could be developed. In this paper, a cost-effective autocatalytic graded Ni-Cu-P-PTFE composite coating with corrosion-resistant properties was applied to reduce biofouling formation. The experimental results showed that the surface free energy of the Ni-Cu-P-PTFE coatings, which were altered by changing the PTFE content in the coatings, had a significant influence on the adhesion of microbial and mineral deposits. The Ni-Cu-P-PTFE coatings with defined surface free energy reduced the adhesion of these deposits significantly. The anti-bacterial mechanism of the composite coatings was explained with the extended DLVO theory.     

无芯胶管的研制、工艺现状和发展建议

20世纪60年代初,我国胶管领域自主开发创新研制了无芯胶管制造技术,并且形成定型技术,一直沿用至今,笔者参与、见证了该产品从试验到投产的全过程。本文对该产品的工艺进行了新旧对比,提出了今后发展的建议。     

新型液晶PVDF合金的研究

本文系统地研究了液晶聚合物(LCP)与PVDF合金共混体系的组成及加工工艺条件对共混物制件性能的影响。并用SEM观察了合金的形态结构。结果表明:在液晶含量10%左右时,加工温度为210℃,合金的拉伸强度最高,磨耗量最低,体系分散均匀并形成了较多的微纤结构。     

我国化肥催化剂工业现状

全国48家化肥催化剂制造厂总能力为57Kt/a,产量近30kt/a,设备利用率不到50%。平均万吨氨耗催化剂10.36t,高于国外5.60t水平。现生产31个品种203个型号的催化剂中有103种经部级鉴定,但经常使用的约50种。目前化肥催化剂工业水平与国外相比还存在四方面差距。     

新型节能玻璃钢门窗的研究

本文主要围绕节能主题，从能耗方式、性能指标、结构形式、制作安装等方面论述了玻璃钢门窗在不同气候地区、不同环境和不同领域中的开发和应用。     

二次盐水精制采用5台树脂塔流程简介

介绍了国内首创的离子膜盐水二次精制塔工艺,运行6 a证明本工艺是投资省、见 效快,生产能力大,又切实可行的工艺方法。