纳米陶瓷的烧结研究

纳米陶瓷的制备过程中，烧结是关键一环。总结了现有的烧结理论，介绍了国内外流行的纳米烧结技术，并提出了今后的研究方向。     

红外吸收谱测量过程中的磁场效应

以氢化非晶硅(a-Si∶H)膜处于恒定和交变磁场中,膜中硅氢键(Si-H)相关伸缩振动吸收带(2100cm~(-1)-1900cm~(-1))发生变化的结果来研究磁场对红外吸收谱测量中的影响.     

神经网络在预测中的应用

本文介绍了多层前向神经网络及其学习算法。并利用多层前向神经网络对复杂非线性系统进行预测研究。实验结果证明该方法是有效的。     

掺水化油器的应用研究

介绍了掺水化油器的要点及用于自然吸气式汽油机和涡轮增压汽油机的台架试验结果,并对有关问题作了相应的讨论。     

低阻低噪声前置放大器设计

对用于低温碲镉汞红外探测器的晶体管低阻低噪声前置放大器进行了噪声分析,提出了简便实用的最佳电流设计法.实验验证了结果的实用性     

PTA氧化干燥机BM302电流异常原因分析及处理

针对洛阳石化精对苯二甲酸(简称PTA)装置氧化单元干燥机BM302电流异常,进行全面分析探讨,确定为入口端滚圈与筒体的相对滑动导致的这种情况,并采取相应措施进行处理,取得良好效果,对以后同类设备的运行、维护提供了可借鉴的经验。     

环氧官能化ABS核壳比对增韧PBT性能的影响

采用种子乳液聚合的方法,合成了不同核壳比的甲基丙烯酸缩水甘油酯接枝丙烯腈-丁二烯-苯乙烯塑料耐冲击改性剂(ABS-g-GMA).将合成的耐冲击改性剂用于增韧聚对苯二甲酸丁二酯(PBT),考察耐冲击改性剂核壳比对增韧PBT拉伸性能、缺口冲击强度以及相容性的影响.结果表明,耐冲击改性剂的核壳比对增韧PBT有重要的影响.耐冲...     

Cohesive mechanism of the FeCr/Ni Interface: A first-principles study

Based on previous experimental results, a series of FeCr/Ni interface models have been constructed and analyzed using a first-principles pseudopotential plane-wave method. Several parameters, such as the ideal work of separation (W), formation enthalpy (ΔH), cohesive energy (ΔE), and electronic structure were calculated in order to analyze the bonding performance and adhesion mechanisms of elements along an FeCr/Ni interface. The largest ideal work of separation was obtained for the Fe(100)/Ni(100) interface, which implies that this interface model presented the most stable structure among a series of crystal interface indices, e.g., (100), (110), and (111). With Cr doping, the W of the FeCr(100)/Ni(100) interface was increased by 101.571 mJ/m². The corresponding ΔH and ΔE values also indicated that the FeCr(100)/Ni(100) interface model was strengthened by doping with chromium. Furthermore, the overlap population ratio, R _LBOP (R _LBOP= 1.04), of FeCr(100)/Ni(100) was smaller than that of Fe(100)/Ni(100) (R _LBOP = 1.35), which implies that the toughness of the Fe(100)/Ni(100) interface can be improved by the presence of chromium impurities. Moreover, electronic structure analysis provided an understanding of the mechanical performance of the various Fe(Cr)/Ni interface models. Thus, our findings open a potential avenue for the comprehensive study of composite material designs.     

Characterizations on Mechanical Properties and In Vitro Bioactivity of Biomedical Ti–Nb–Zr–CPP Composites Fabricated by Spark Plasma Sintering

To alleviate the bio-inert of Ti alloys as hard tissue implants, Ti–35Nb–7Zr–xCPP(calcium pyrophosphate,x = 5, 10, 15, 20 wt%) composites were prepared by mechanical alloying(MA) and following spark plasma sintering(SPS). Mechanical behaviours and in vitro bioactivity of these composites were investigated systematically. Results showed that the composites consisted of β-Ti matrix, α-Ti, and metal–ceramic phases such as CaO, CaTiO_3, CaZrO_3, and Ti_xP_y. With increasing CPP content, the composites had higher strength(over 1500 MPa) and higher elastic modulus, but suffered almost zero plastic deformation together with lower relative density. When the CPP contents were 5 and 10 wt%,the compressive elastic moduli were 44 and 48 GPa, respectively, which were close to those of natural bones. However, the compressive elastic modulus of the composites increased significantly when CPP contents exceed 10 wt%, thus deteriorating the mechanical compatibility of the composites owing to more α-Ti and metal–ceramic phases. Besides, the surface of Ti–35Nb–7Zr–10CPP composite was deposited as a homogeneous apatite layer during soaking in simulated body fluid(SBF). It indicates a good bioactivity between the implant materials and living bones.