埋管低温热水辐射地板当量热阻研究

镜像并简化埋管低温热水辐射地板绝热层以上结构，获得地板向上传热的导热形状因子，利用导热形状因子推导出绝热层以上结构当量热阻计算式，提出基于当量热阻的地板散热量的新算法，比较了新算法计算结果和数值模拟法结果，证明当量热阻算法计算准确，为埋管低温热水地板辐射供暖工程设计提供了方便灵活的地板散热量计算方法。     

不同电参数对CFRC应变敏感性的响应

CFRC具有压敏性，测试方法和测试参数的选择对CFRC的压敏性有一定的影响。采用直流电阻测试法、交流阻抗测试法和电容测试法研究了不同电参数(直流电阻、交流阻抗、电容)对CFRC应变敏感性的响应。实验结果表明：直流电阻和交流阻抗随压力的变化都能反映试样受载变形的全过程：弹性阶段、损伤阶段、破坏阶段；电容随压力的增大而增大；交流阻抗和电容随应变的变化比直流电阻随应变的变化灵敏且稳定。最后对这3种测试方法作了综合评价。     

信息化--传统防锈模式面临的挑战

根据传统制造业产品防锈过程的特点及存在的问题，分析了制造业产品防锈信息化的起因和重要性，并介绍了防锈信息系统的功能和用途。通过防锈信息系统输入、处理、输出和模拟运行进一步阐明了防锈信息系统的原理、应用及其广阔的发展前景。     

Surface Alloying of Nitrogen to Improve Corrosion Resistance of Steels and Stainless Steels

It is well known that the addition of nitrogen to steels and stainless steels enhances the passivity and localized corrosion resistance, in addition to improving the mechanical properties. Selective alloying of surfaces of steels and stainless steels with nitrogen could also enhance the corrosion resistance and improve the mechanical properties without affecting the bulk properties. Techniques like ion implantation, laser alloying, nitriding, etc. can be effectively used to introduce very high levels of nitrogen. In addition, these techniques can also produce modified surfaces with novel microstructures to further improve the properties. The surface alloying methods also provide an opportunity to selectively nitrogenate the surface of finished components in order to obtain better properties. The review highlights the techniques, modifications and the properties obtained further.     

Thermal characterization of gallium arsenic nitride epilayer on gallium arsenide substrate using pulsed photothermal reflectance technique

Thermal conductivity of gallium arsenic nitride (GaAsN) epilayer on gallium arsenide (GaAs) substrate prepared by molecular beam epitaxy technique was measured using pulsed photothermal reflectance technique. Three-layer model incorporated thermal boundary resistance was applied to extract the thermal properties from the sample's photothermal response. Within the thickness ranging from 20 to 80 nm, no thickness dependent relationship with thermal conductivity of GaAsN epilayer was found, and the average thermal conductivity is approximately 27 W/mK at room temperature. The thermal boundary resistance at the Au/GaAsN interface is in the order of 10⁻⁸ m²K/W.     

Research on Processes and Adhesion of Electroless Plating Ni-Cu-P Coating

In order to improve the corrosion and wear resistance of the coatings of electroless plating Ni-Cu-P and broaden its application, an optimizing mathematical theory test has been applied in this research. The processing parameters have been optimized and some Ni-Cu-P coatings have been obtained with smooth and glittering appearance. At the same time,the composite complexants can prevent copper from depositing first and obtain coatings with strong adhesion. The porosity of Ni-Cu-P coating (20 μm) ranked class 9. The changing color time of the coating is more than 800 seconds with HNO3 dropthan 0.5 g/L. The surface appearance of deposition is typical cystiform cells by SEM,which rank close and neatly.     

Research About Microstructure and Wear Resistance of Hardfacing Layer on Cast Iron

It's simple technology to manufacture big trimming die by hardfacing on the base metal of cast iron. The chemical composition, microstructure, hardness, wear resistance and wear mechanism of the hardfacing layer were studied.The experimental results indicate that the hardfacing technology has much more advantages and cheaper than that of traditional process. The chemical composition, microstructure, hardness of the hardfacing metal are all satisfied for manufacturing the big trimming die by welding on cast iron. The wear resistant test of hardfacing layers were carried out by using two different electrodes. The wear resistance of new electrode hardfacing layer is higher than that of normal hardfacing electrode D322. The wear mechanism of hardfacing layer is belongs to abrasive wear model.     

全钒液流电池隔膜在钒溶液中的性能

考察了Nafion、日-160、日-80、FYM(日本产Nafion膜)和均相膜5种离子交换膜的两个关键性能(渗透性和面电阻)及其影响因素,对均相膜的化学稳定性进行了初步研究,并对两种膜进行了改性。实验发现:均相膜的钒扩散系数最小,但面电阻较大,化学稳定性不好;用二乙烯苯(DVB)对均相膜改性,综合性能较好;减小电场可降低钒离子扩散,提高钒溶液中氢离子浓度可减小面电阻。     

钙锡含量对铅钙合金耐腐蚀性能的影响

为了研究铅钙合金中,锡钙含量对其耐腐蚀性能的影响,笔者设计并配制了不同锡钙含量的铅钙合金试样。通过对试样的腐蚀电位、腐蚀阻抗、析氢过电位的测试,结果表明:在铅钙合金中,随着锡含量的上升和钙含量的降低,合金的耐腐蚀性和析氢过电位都有所提高。     

关于经电阻接地小电流接地系统的研究

重点分析了电网在发生单相接地故障时的电流分布,讨论了在不接地系统中增加接地点的可能性以及增加接地点的方法,并对各种现有的方法进行了分析,最后提出了增加接地变压器的可行方案和对于此系统继电保护整定的要求,以实现低压系统发生单相接地故障时,通过保护装置跳闸切除故障,防止损坏一次设备的事故发生。