单轴-平面W型复合锶铁氧体的制备及其吸波特性研究

用草酸盐共沉淀和微量掺杂法研制六角晶系W型Ni,Zn,Co,Al多元复合锶铁氧体，通过调节Ni2W同Co2W的摩尔比例，可使该种铁氧体易磁化方向从C单轴型向垂于C轴的平面型转化，控制置换锶铁氧体中部分Fe3 的微量掺杂Al3 ，可以调整4πMs值，提高磁晶各向异性场，测试分析了5种不同含Co量的W型复合锶铁氧体粉料涂层的吸波特性，发现其自然共振吸收峰随Co含量增加向低频方向偏移，最高吸收峰可达32．8dB，是适用于电子隐形技术的高品位的微波吸收剂。     

A damage identification technique for CF/EP composite laminates using distributed piezoelectric transducers

In this study, a damage identification approach was developed for carbon fibre/epoxy composite laminates with localized internal delamination. Propagation of the Lamb wave in laminates and its interaction with the delamination were examined. The fundamental symmetric Lamb wave mode, S₀, and the lowest order shear wave mode, S₀^′, were chosen to predict damage location. A real-time active diagnosis system was therefore established. This technique uses distributed piezoelectric transducers to generate and monitor the ultrasonic Lamb wave with narrowband frequency. The two-way switches were employed to minimize the number of transducers. A signal-processing scheme based on the time–frequency spectrographic analysis was utilised to extract useful diagnostic information. Also, an optimal identification method was applied on damage searching procedure to reduce errors and obtain the diagnostic results promptly. Experiments were conducted on [0/−45/45/90]_s CF/EP laminates to verify this diagnosis system. The results obtained show that satisfactory detection accuracy could be achieved.     

化学镀Ni-P合金/TiO2复合膜的耐蚀性研究

在改进常规制备方法的基础上，提出化学镀/溶胶-凝胶复合法在碳钢表面制备TiO2复合膜的新技术。用衍射研究了复合膜的组织形态，采用环境扫描电镜（ESEM）表征了复合膜的表观和断面形貌，用极化电阻、阳极极化曲线测量等方法研究TiO2复合膜在0.5mol/L硫酸和0.5mol/L氯化钠溶液中的耐蚀性能。结果表明A3钢表面的TiO2复合膜耐蚀性能优良。     

含预制分层损伤复合材料层合板在压缩载荷下破坏过程和剩余强度的模拟

本文运用一种具有较高精度的高阶位移模式,结合特定的损伤判据和刚度折减方法,建立了一种含损伤有限元模型,并利用其对多个含预制分层损伤的复合材料层合板在压缩载荷下的破坏过程进行了数值模拟,并最终得到这些层合板的剩余强度。与实验结果的对比表明,该数值模拟方法具有较高的精度和有效性。     

反应自生Al_3Ni－Al_2O_3－Al复合材料

通过热力学计算，选择Ｎｉ_２Ｏ_３粉末作原材料，采用反应挤压铸造方法实现了Ａｌ与Ｎｉ２Ｏ３直接压铸反应合成Ａｌ３Ｎｉ－Ａｌ２Ｏ３－Ａｌ原位复合材料。研究了压铸工艺参数和预制块中纯Ａｌ粉的含量对反应合成复合材料过程的影响，并对反应机理做了较深入的分析。结果表明，Ｎｉ２Ｏ３与Ａｌ的反应是为高放热反应，反应是爆发式的，通过调整预制块中Ａｌ粉的体积分数控制了反应的剧烈程度，并能获得不同组成和基体含量的复合材料。对反应机理的分析表明，在Ａｌ足量的情况下，Ｎｉ２Ｏ３与Ａｌ反应合成复合材料分为两个过程，一是反应过程，即Ｎｉ２Ｏ３＋Ａｌ→Ａｌ２Ｏ３＋［Ｎｉ］；二是凝固过程，即反应后多余的Ａｌ与反应生成的［Ｎｉ］在随后冷却中的凝固过程，最终形成Ａｌ３Ｎｉ＋α－Ａｌ２Ｏ３＋Ａｌ复合材料。     

碳纤维缠绕复合材料在潜水外压容器上的应用

在铝合金圆筒体外以浸渍树脂碳纤维进行缠绕复合增强，增强后的筒体耐静水外压能力大幅度提高；整体缠绕的全复合材料筒体，在耐静水外压能力及减轻自身重量方面也获得了明显的效果。此外，在铝合金细长圆管的外壁复合缠绕碳纤维，能有效地提高圆管对轴向压载荷的抗失稳与抗屈曲破坏能力。     

两种不同界面结合强度碳/铝复合材料的内耗特性

本文研究了两种不同界面结合强度的碳/铝复合材料经不同次数加载热循环处理后的内耗值及内耗机制。弱界面结合的C/L2复合材料的内耗值变化主要由界面脱粘引起,而强界面结合的C/LD2复合材料的内耗值变化主要由位错运动所致。     

PAA-PSF交联复合膜的制备及对低浓度有机醇水溶液反渗透分离性能研究

进行了ＰＡＡ（ＰｏｌｙａｃｒｙｌｉｃＡｃｉｄ）－ＰＳＦ（Ｐｏｌｙｓｕｌｆｏｎｅ）交联复合膜的制备，研究了交联剂、添加剂对膜性能的影响，并通过扫描电镜观察了膜的断面结构．研究了ＰＡＡ－ＰＳＦ交联复合膜对低浓度有机醇类水溶液反渗透分离性能．发现对于１０００×１０－６乙醇水溶液截留率达到６６．２％，透过流束可达０．９×１０－６（ｍ３·ｍ－２·ｓ－１）．随醇的分子量的增加，截留率不断上升，对戊醇的截留率达９４．３％，而透过流束则保持相对稳定．对不同结构醇类的分离性能研究表明，截留率存在有：ｔｅｒｔ－＞ｓｅｃ－＞ｉｓｏ－＞ｎ－的规律．     

�ø������ռ�ͬʱ�ѳ���Ȼ���е������ˮ

本文介绍了采用复合吸收剂净化天然气的试验结果,在现有三甘醇等脱水剂中添加单乙醇胺,在脱水的同时脱除H_2S,在保证净化气露点低于-21℃的条件下,使净化气中H_2S含量亦低于5mg/m～3。     

Tc trend in high-Tc superconductors

In our previous works, we have shown that most existing ceramic superconductors can be considered to be built of superconductor-semiconductor composite and we have estimated the change in phonon spectrum of the intrinsic superconductor unit if a semiconductor unit is attached to it. Moreover, the proximity effect under the size quantization condition has been examined in the superconductor-semiconductor composite. Each of the stated effects by itself could causeT _c enhancement in general as more semiconductor blocks are added to the system. We extend our study in this paper to analyze the combined actions of phonon spectral change and proximity effect without size quantization condition onT _c variation in members of the Tl₁ series of high-T _c superconductors. Our results indicate that an optimumT _c is obtained if the stated effects are included in the idealized unit cells of the superconductors made up of a superconductor-semiconductor array.