室温固化型高温粘结剂的制备及其性能

利用高温粘结剂是实现炭材料连接最有效的方法。在组成为酚醛树脂和B4C的高温粘结剂基础上，向其中添加一定量的H3PO4固化剂制备室温固化型高温粘结剂，并对石墨材料进行粘接。对不同温度热处理后的粘接样品进行剪切强度测试。结果表明，室温固化型高温粘结剂对石墨材料具有良好的粘接性能。与原有的200℃加热固化的高温粘结剂相比，粘接强度有所提高。此外，对不同条件处理后的粘接性能与结构相关性也进行了研究。发现固化剂磷酸在高温处理后缩聚为多聚磷酸，并和石墨基体发生了键合连接。     

石墨高温粘接部件的抗热震性能研究

以酚醛树脂（Phenol-Formaldehyde Resin,PF)和B4C、SiO2为原料制备了高温粘结剂，并对石墨材料进行高温粘接，同时考察了粘接石墨制品经历ΔT=800℃和ΔT＝1000℃温度交变后的抗热震性能。结果表明，用该粘结剂粘接的石墨样品有着优良的抗热震性能，经历数次热震后其强度保持率仍然较高。此外，还对影响粘接样品抗热震性能的因素进行了理论探讨，指出优化原料性质、提高热处理温度、控制胶层厚度等对提高抗热震性能有重要的影响。     

热处理对高温粘结石墨部件导电性能的影响

以酚醛树脂和B4C为原料制备高温粘结剂并对石墨材料进行粘接，测试了经不同温度热处理后接头部位的导电性能。并利用XRD和SEM对热处理后的粘接接头结构进行了表征。结果表明，热处理温度对粘接接头的导电性能有着决定性的作用。1000℃以下的热处理阶段，随温度的升高，石墨接头的电阻率迅速降低，1000℃以上高温热处理后接头的导电性能良好，电阻率变化不大。此外，由于B4C的半导体特性和高温下的催化石墨化作用，B4C对石墨接头的导电性能也有着重要的影响。     

石墨高温粘接界面的组成及其与粘接强度间的关系

以酚醛树脂和碳化硼为原料制备了性能良好的调温粘结剂并对石墨材料进行粘接。通过XPS的测试，研究了石墨调温粘接样品在不同的温度热处理后的界面组成，相对含量变化及其与粘接性能间的相关性。结果表明，粘接界面上主要存在着C，B，O等元素，其中，酚醛树脂（PF）炭化产生的无定形炭构成了胶层骨架，其相对含量的变化影响着胶层结构的致密稳定性；B在粘接样品中以B4C或B2O3形式存在，其存在形式对粘接强度有着重要的影响。     

不同添加剂对石墨材料高温粘结性能的影响

在以酸醛树脂（PF）和碳化硼（B4C）为原料的高温粘结剂的基础上，Al2O3,Si和白炭黑（超细SiO2）作为第二种添加剂分别加入到粘结剂中以制备新型高温粘结剂，并对石墨材料进行粘结。用新型高温粘结剂粘结的石墨部件分别为200、800、1500℃下热处理，并在室温条件下测试其剪切强度。结果表明，复合添加剂对石墨粘结部件的粘结性能有明显的影响。其中，酚醛树脂＋B4C＋白炭黑粘结剂具有较为理想的粘结性能，白炭黑的添加对提高石墨材料的高温粘结性能具有明显的作用。     

白炭黑、B4C改性酚醛树脂粘接石墨高温性能研究

在B4C改性酚醛树脂（phenol-formaldehyde resin,PF)高温粘接剂的基础上,向其中添加白炭黑（超细SiO2)制备新型粘接剂,并对石墨材料进行粘接和热处理,测试了不同温度热处理后的粘接强度。结果表明,2550℃处理后新型粘接剂仍具有理想的耐热温度和粘接强度。利用扫描电镜（SEM）对样品断面形貌进行观察,研究了粘接界面的组成和结构变化及其与粘接性能之间的关系。实验结果表明,白炭黑的添加,对提高胶层的致密性和粘接强度具有明显的效果。     

B4C在石墨高温粘接过程中的组成和结构变化及改性机理

以酚醛树脂（Ｐｈｅｎｏｌ－ｆｏｒｍａｌｄｅｈｙｄｅ ｒｅｓｉｎ,ＰＦ）和Ｂ４Ｃ原料制备的高温粘接剂,对石墨材料进行粘接,并在２００℃、８００℃和１５００℃进行热处理。对粘接样品的强度测试结果表明,粘接部件具有较高的面热温度和粘接强度。利用扫描电镜（ＳＥＭ）和Ｘ射线衍射（ＸＲＤ）对不同温度热处理后的粘接界面结构形貌及粘接剂组成进行了分析,研究了酚醛树脂中的Ｂ４Ｃ添加剂在粘接过程中的结构变化及其对提高     

B_4C在石墨高温粘接过程中的组成和结构变化及改性机理

以酚醛树脂 (Phenol- form aldehyde resin,PF)和 B4C为原料制备的高温粘接剂 ,对石墨材料进行粘接 ,并在 2 0 0℃、80 0℃和 15 0 0℃进行热处理。对粘接样品的强度测试结果表明 ,粘接部件具有较高的耐热温度和粘接强度。利用扫描电镜 (SEM)和 X射线衍射 (XRD)对不同温度热处理后的粘接界面结构形貌及粘接剂组成进行了分析 ,研究了酚醛树脂中的 B4C添加剂在粘接过程中的结构变化及其对提高粘接性能的作用机理。     

白炭黑,B4C改性酚醛树脂热解过程的红外分析

以白炭黑（超细ＳｉＯ２）、Ｂ４Ｃ对酚醛树脂（Ｐｈｅｎｏｌ－Ｆｏｒｍａｌｄｅｈｙｄｅ Ｒｅｓｉｎ,ＰＦ）改性后制备的高温粘结剂具有较好的粘接效果,本文借助于红外光谱（ＩＲ）对不同温度热处理后的粘接样品进行结构分析,以考察热解过程中的结构变化特点及其与性能间的相关性。     

质子交换膜燃料电池复合材料双极板的研究

以高分子预聚物为粘合剂，天然或人造石墨为导电骨料，通过模压一次成型制备质子交换膜燃料电池双极板。研究了导电骨料的组分、树脂的种类及其含量，成型温度、成型压力对双极板性能的影响。结果表明：1)导电骨料的组分、树脂的种类及其含量对制品的性能影响较大；成型温度、成型压力对制品的性能影响较小。2)人造和天然两种石墨混合组分为导电骨料的制品，其导电性能明显高于单一石墨组分的制品；乙烯基树脂为粘合剂的性能优于以邻苯基树脂为粘合剂的双极板的性能。3)使用质量分数为16％～18％的乙烯基树脂作粘结剂，在成型压力为10MPa～20MPa，成型温度为150℃～200℃时制备的复合材料双极板的电导率＞300S／cm，抗折强度＞30MPa，空气透气率为10^-7cm^2／S。     

Simulation of dye adsorption by beech sawdust as affected by pH

The effect of pH on the batch kinetics of methylene blue adsorption on beech sawdust was simulated, in order to evaluate sawdust potential use as low cost adsorbent for wastewater dye removal. The zero point of charge pH(pzc) of the sawdust, in order to explain the effect of pH in terms of pH(pzc), was measured by the mass titration and the automatic titration methods. The adsorption capacity, estimated according to Freundlich's model, indicate that increase of the pH enhances the adsorption behaviour of the examined material. The lower adsorption of methylene blue at acidic pH is due to the presence of excess H(+) ions that compete with the dye cation for adsorption sites. As the pH of the system increases, the number of positively charged sites decreases while the number of the negatively charged sites increases. The negatively charged sites favour the adsorption of dye cation due to electrostatic attraction. The increase in initial pH from 8.0 to 11.5 increases the amount of dye adsorbed.     

应用PCI总线的音频处理系统的设计

讨论了一种关于音频调理的方法，由于该系统对传输要求比较高，所以系统的传输速度和效率都是很重要的性能指标，在系统的性能指标基础上，选定了PCI总线接口的方案，为简化电路，论文采用PLX公司的PCI9054芯片实现PCI接口，用FPGA实现FIFO数据缓存和本地总线控制逻辑，使通过音频处理后的声音信号通过声音编解码器出去。最后编写了该系统的驱动程序以及应用程序，达到了预期效果。     

Treatment of groundwater polluted by arsenic compounds by zero valent iron

Batch experiments were carried out to study the kinetics and efficiency of inorganic arsenic removal by zero valent iron (ZVI) powder, and as well as the effects of pH, anions, and humic material (HM) on this process. Moreover, column experiment was conducted for 31 days to treat arsenate solution of 500 microg As/L using waste iron chippings as filling. Batch experiments showed that both arsenate and arsenite compounds could be removed efficiently from simulated groundwater by ZVI under aerobic and relative anaerobic conditions. Aerobic condition was favorable to arsenic removal especially for arsenate, while arsenite could be removed more rapidly than arsenate in relative anaerobic condition. Oxidation of arsenite to arsenate by iron species in aerobic environment was observed, which is thought to be an important pathway of arsenite removal. In an unsealed system, the removal efficiency of both arsenate and arsenite decreased at higher pH value. In a sealed system, acidic and alkaline condition seemed to be favorable for arsenate and arsenite removal, respectively. Phosphate and low concentration sulfate caused a decrease in arsenate removal, while high concentration sulfate as well as nitrate caused slight increase in arsenate removal. Presence of HM in solution slightly inhibited arsenic removal. Arsenic removal efficiency in column study was influenced by flow rate and work period of the column. More than 98% of arsenate could be removed stably with a hydraulic resident time of 2 h at last, and the effluent meet the drinking water standard.     

Evolution of the Microstructure by High Velocity Impacts of Particles by Cold Spray

The cold spray technique is still in its innovation stage. This process is similar to other thermal coating techniques with the additional benefit of lower working temperature than the melting energy of the feedstock material. In this study, a new coating–substrate system is developed by using the 80%Ni–20%Cr feedstock powder sprayed by this technique on a superni 601 superalloy substrate. The coating microstructure depends upon both the substrate and coating material properties, and thus, coating obtained in this study has a unique microstructure. The coating microstructure developed and tested in this study by scanning electron microscopy/energy-dispersive x-ray spectroscopy (SEM/EDX) and X-ray diffraction (XRD) techniques is found to be suitable for boilers and incinerators.     

Study of electromagnetic diffraction by curved strip gratings by use of the C-method

The C-method is one of the most efficient and versatile methods designed for diffraction gratings. Its strength lies in the use of a coordinate system in which the surface of the grating coincides with a coordinate surface. The result is a great simplification in writing the boundary conditions. We exploit this simplification to treat the problem of diffraction from curved strip gratings, and we use the combined boundary conditions method that has been introduced for planar strip gratings and proved to be very efficient.     

由PDMS与PVC共热解聚碳硅烷制备SiC-C纤维

以聚二甲基硅烷(PDMS)与聚氯乙烯(PVC)为原料,经过共热解聚合反应合成了聚碳硅烷(PCS P),并制备出SiC C纤维.利用IR、XRD、XPS等分析方法对先驱体PCS P与SiC C纤维的组成、结构与性能进行了研究.结果表明,在PVC的引入量适当的条件下,通过共热聚将少量的短碳链引入到聚碳硅烷结构中,使SiC-C纤维的电阻率显著降低到10-1～101Ω·cm,并保持了良好的结晶性和耐氧化性.     

Bubble propagation by disks formed by ion-implantation

The investigation of implantation conditions for bubble propagation points to the necessity for a minimum dose (1.5 times 10^{16}ions cm²) and a sufficiently thick profile (0.4 μ). The use of flat profiles gives uniform implanted layers and allows values of the maximum defect concentration far away from the amorphization threshold. Unlike in permalloy circuits, bubble stability and bias field margins do not increase with the drive field. The propagation is not critically dependent upon disk diameter and spacing.