基于BP模型的Ni-SiC镀层镀速预测研究

采用超声波辅助电沉积法,在45钢表面制备Ni-SiC镀层,研究不同工艺参数对Ni-SiC镀层镀速的影响。采用3×6×1型BP模型对Ni-SiC镀层的镀速进行研究。结果表明:Ni-SiC镀层中SiC颗粒的平均粒径为158 nm,镍晶粒的平均粒径为714 nm;BP模型预测值曲线与实验值曲线吻合度较高,其最大相对误差为2.4%,相关系数为0.998。该BP模型具有很好的自适应能力。     

TATB原位包覆HMX的研究

为提高TATB对HMX的钝化效果,利用声化学合成方法,在HMX颗粒表面原位生成了TATB,制备了HMX/TATB复合物。并与混合法制备的样品进行了比较。SEM观察表明,原位包覆法TATB对HMX的包覆效果比混合法的包覆效果更好。DSC分析表明,原位包覆法样品中HMX的热分解温度更高。机械感度测试结果表明,在TATB含量相当的情况下,原位包覆法样品具有更低的机械感度,在TATB含量为10%时,撞击感度为24%,摩擦感度为0%。     

Effect of catch cup geometry on 3D boundary layer flow over the wafer surface in a spin coating

Recently, development of high technology has been required for the formation of thin uniform film in manufacturing processes of semiconductor as the semiconductor instruments become more sophisticated. Spin coating is usually used for spreading photoresist on a wafer surface. However, since rotating speed of the disk is very high in spin coating, the dropped photoresist scarers outward and reattaches on the film surface. A catch cup is set up outside the wafer in spin coating, and scattered photoresist mist is removed from the wafer edge by the exhaust flow generated at the gap between the wafer edge and the catch cup. In the dry process of a spin coating, it is a serious concern that the film thickness increases near the wafer edge in the case of low rotating speed. The purpose of this study is to make clear the effect of the catch cup geometry on the 3D boundary layer flow over the wafer surface and the drying rate of liquid film.     

太阳能级多晶硅铸锭免烧结坩埚的喷涂工艺研究

研究一种太阳能级多晶硅铸锭用坩埚的免烧结喷涂工艺技术,分析该工艺技术对太阳能级多晶硅锭、多晶硅块、多晶硅片的影响。试验证明,该工艺技术在不影响太阳能级多晶硅锭、硅块、硅片性能的基础上,显著降低生产成本,极大地提高了生产效率。     

纳米颗粒在防腐蚀涂料中的应用

介绍了纳米材料在防腐蚀涂料中的应用,分析了颗粒的分散和几种颗粒改性防腐蚀涂料。纳米颗粒由于其优异的性能,适量添加,能够提高涂料的耐腐蚀性能。     

TATB表面包覆高能硝胺发射药的性能研究

为了改善高能硝胺发射药的燃烧性能,且不降低其总能量,将低能炸药TATB加入硝胺药中作为包覆剂对高能硝胺发射药进行包覆处理;通过爆热、密闭爆发器和12．7mm机枪内弹道试验,研究了包覆发射药的能量性能、静态燃烧性能和内弹道性能;结果表明：包覆样品CF-1能量与高能硝胺药相当,且表现出较强的燃烧渐增性,对比高能硝胺药,包覆样品CF-1弹丸初速提高了5％,且具有低温度系数效果。     

Wire rod coating process of gas diffusion layers fabrication for proton exchange membrane fuel cells

Gas diffusion layers (GDLs) were fabricated using non-woven carbon paper as a macro-porous layer substrate developed by Hollingsworth & Vose Company. A commercially viable coating process was developed using wire rod for coating micro-porous layer by a single pass. The thickness as well as carbon loading in the micro-porous layer was controlled by selecting appropriate wire thickness of the wire rod. Slurry compositions with solid loading as high as 10 wt.% using nano-chain and nano-fiber type carbons were developed using dispersion agents to provide cohesive and homogenous micro-porous layer without any mud-cracking. The surface morphology, wetting characteristics and pore size distribution of the wire rod coated GDLs were examined using FESEM, Goniometer and Hg porosimetry, respectively. The GDLs were evaluated in single cell PEMFC under various operating conditions (temperature and RH) using hydrogen and air as reactants. It was observed that the wire rod coated micro-porous layer with 10 wt.% nano-fibrous carbon based GDLs showed the highest fuel cell performance at 85 °C using H₂ and air at 50% RH, compared to all other compositions.     

WC和Al2O3对氩弧熔覆FeAlCoCrCuTi0.4高熵合金涂层组织和耐冲蚀性能影响

利用氩弧熔覆技术制备了FeAlCoCrCuTi0.4,WC/Al2O3-FeAlCoCrCuTi0.4高熵合金涂层,并通过XRD,SEM,EDS,硬度测试和冲蚀磨损测试等方法,探究了WC和Al2O3的添加对FeAlCoCrCuTi0.4高熵合金涂层显微组织和性能的影响.结果表明,通过氩弧熔覆技术所制备的合金涂层表面成形性良好,无孔洞、裂纹等缺陷产生,与基体呈高强度冶金结合.WC和Al2O3的添加对涂层稀释率的降低有显著作用.三种涂层都是主要由Bcc相(Fe-Cr固溶体)构成,晶粒以胞状树枝晶形式存在.添加WC后,晶粒细化明显,在各种强化作用下涂层硬度为685.8HV.且WC和Al2O3的添加显著提高了涂层耐冲蚀磨损性能,耐磨性几乎可以达到FeAlCoCrCuTi0.4高熵合金涂层的2倍.     

高岭土选矿工艺研究

广东省高岭土资源非常丰富，本文着重介绍了对四会，成名，靖远，湛江等地高岭土矿所仨的选矿试验研究以及利用高岭土矿石生产刀刀级与刮刀级造泖布土的工艺。     

各向异性材料部分涂覆导体的散射特性研究

利用物理光学法(PO)与有限元法(FEM)混合方法,研究了有各向异性媒质局部涂覆的电大导体目标的电磁散射问题.在有复杂媒质涂覆的电小结构区域采用有限元法,在未涂覆媒质的电大导体区域采用物理光学法结合等效电磁流法.将两部分区域的边界进行消隐处理,考虑耦合效应,并利用共同的等相位面,将不同区域产生的散射场矢量叠加得到总散射场.文中的实例结果与传统的FEM很好的一致,说明了该方法的有效性和精确性.