羟甲基共聚酰胺的制备和研究

以甲酸为催化剂，甲醛与共聚酰妥ＰＡ（６／１０１０）缩合，制备羟甲基聚酰胺。利用小角激光散射、ＤＴＡ谱图，比民阻、接触角测定、应力－应弯曲线粘接试验等手段对其进行了研究。羟甲基以后，共聚酰胺的结晶形态发生了变化，熔点下降，断裂力降低但亲水性提高，对铝材的粘接力增大。通过对其固化体系和固化条件的调整，可以增加固化程度并强化对铝材的粘接能力。     

Surface Orientation and Wetting Phenomena in Si/α-Alumina System at 1723 K

Wetting phenomena and the effect of alumina surface orientation on the wettability in Si/α-Al₂O₃ system were studied by an improved sessile drop method using     ,     , C(0001) faces of single crystals and polycrystals at 1723 K in a reducing Ar–3% H₂ atmosphere. The contact angles show a vibration behavior for all the single crystals but to a less extent for the polycrystals. The extent of the vibration correlates not only with the reaction intensity but also with the stability of the Si droplet on the alumina surfaces. The interfacial reaction leads to the formation of a series of reaction rings, which is more serious at the single crystal surfaces. More importantly, the wettability is dependent on the alumina surface orientation, with the intrinsic contact angles being about 98±2°, 101±1°, 69±1°, and 98±2°, respectively, for the     ,     , C(0001) and polycrystal α-Al₂O₃ substrates. The much smaller contact angle for molten Si on the C(0001) surface is explained by the favorable reduction in the Si/α-Al₂O₃ interfacial free energy by the terminated and enriched aluminum atoms at the reconstructed     surface. The importance of the aluminum presence at the Si/α-Al₂O₃ interface to the wettability of this system was further demonstrated by a substantial improvement in the wettability of the     α-Al₂O₃ substrates by Si–Al alloys.     

Development and evaluation of terminally epoxidized triglycerides for coatings applications

Epoxidized 10-undecenoic acid triglyceride, an experimental seed oil derivative that has a terminal epoxy group on each of the three acyl glyceride segments, has been found to have good reactivity with amine curatives and allows room temperature cures to be obtained. Coatings based on epoxidized 10-undercenoic acid triglyceride have also shown excellent UV stability. As an example, coatings samples placed in a QUVA chamber exhibit no loss in gloss after 3000 hr of a cycled exposure to high intensity UV lamps and moisture at temperatures of 50–60°C. In comparison, coatings based on standard liquid epoxy resins (LERs) and commercially available hydrogenated LERs lose gloss due to chalking/decomposition within 200–800 hr. Presented at the 81 st Annual Meeting of the Federation of Societies for Coatings Technology, November 12–14, 2003, in Philadelphia, PA.     

Degradation of a textile azo dye by pulsed arc discharge to the surface of wastewater

The pulsed arc discharge to the surface of wastewater was applied to the degradation of a textile azo dye (Acid Red 27). A high-voltage electrode (discharging electrode) was vertically placed above the surface of the wastewater while the wastewater itself was grounded. The pulsed arc discharge occurred between the tip of the discharging electrode and the surface of the wastewater, producing various oxidative species. Oxygen was used as the working gas instead of air to prevent nitrogen oxides from forming. The effect of several parameters on the chromaticity and chemical oxygen demand (COD) removal was examined. The results obtained showed that the chromaticity of the wastewater was completely removed by this process and the COD also decreased significantly. It has been found that ozone formed in the gas phase mainly affects the removal of the dye. The contribution of other effects such as ultraviolet light emission and OH radical formation during the arc discharge to the degradation of the dye was found to be less than 15%. For the present reactor system, the optimum pH, pulse repetition rate and agitation speed were found to be 3.0, 110 Hz and 300 rpm, respectively.     

电力信息和通信技术推动智能电网建设

智能电网的发展带动了电网发电、输电、变电、配电、用电等各个领域的巨大变革,电力信息和通信技术作为智能电网发展的关键性技术,对智能电网发展起到巨大的支撑作用。本文分析了智能电网建设中信息通信的重要性,并从网络融合、电网增值／具体领域应用等方面,分析了电力信息和通信技术对智能电网的推动作用。     

Purification of 2-mercaptobenzothiazole by solvent extraction

−Purification of 2-mercaptobenzothiazole (91.9% purity) by solvent extraction was studied. The extraction of impurities present in crude 2-MBT (e.g. benzothiazole, sulfides and sulfur containing compounds) was carried out at temperatures between 70-180°C using various solvents and their mixtures of different polarity. The highest purity of 2-MBT, above 99% was obtained using nitrobenzene, toluene and ethanol, even at a concentration of 2-MBT above 50 wt%. Increasing temperature and decreasing concentration of the raw material have a positive influence on the purification process. A comparable efficiency of purification was observed also with mixed solvents, (toluene with ethanol, acetone and aniline) possessing the same polarities. A correlation between the polarity indexes (PI) of mixed solvents and experimentally obtained purity of 2-MBT was found. The highest purity of 2-MBT provides extraction of the raw material with mixed solvents having PI 3.8-4.4.     

Synthesis and properties of chitosan-modified poly(vinyl butyrate)

Modification of chitosan by grafting of vinyl butyrate was carried out in homogeneous phase using potassium persulfate as redox initator and 1.5% acetic acid as solvent. The percent grafting and grafting efficiency were analysed and the high grafting efficiency up to 94% was observed. The effects of reaction variables such as monomer concentration, initiator concentration, temperature and reaction time were investigated. It was observed that the solubility of chitosan was markedly reduced after grafting with vinyl butyrate. The grafted product is insoluble in common organic solvents as well in dilute organic and inorganic acids. Characterization of the graft copolymers were carried out by using Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC) and Scanning Electron Microscopy (SEM) technics. Characteristic signal of carbonyl group was observed at 1,731 cm⁻¹ which belongs to the poly vinyl butyrate segments in the graft copolymer. The melting transition of the chitosan main chain in the copolymer shifted to 124°C from its original value 101°C. In addition to these, we have also studied topology of the graft copolymer and the SEM micrograph showed continuous homogenous matrix which means there is no phase separation.     

企业电子商务异构数据集成模型研究

通过研究XML在数据集成方面的相关技术,提出了一个基于XML企业电子商务异构数据集成框架,可以无缝地与面向对象系统、数据仓库系统等进行接口,能够较好地实现系统之间动态资源共享和交流,为企业之间对各种分布异构数据库资源提供了全局、统一、动态和高效的访问.     

4G通信技术的FPGA远程更新系统设计

为了解决在恶劣环境、偏远地区等特殊场合的FPGA远程更新问题,提出了一种基于4G无线通信技术的FPGA远程更新系统设计方法。应用4G无线通信模块实现了更新控制器的通信组网,远程控制器通过4G网络与更新控制器建立通信连接,下发控制命令实现FPGA的远程更新。通过实际测试验证了新方法的可行性、正确性,有效弥补了传统更新方法布线复杂、效率低、距离短等不足,提高了设备维护效率、降低了维护成本,对工程应用具有重大意义。     

可见光-远红外图像的多模态能见度深度学习模型

为了增强能见度深度学习模型在小样本条件下的准确率和鲁棒性,提出一种基于可见光-远红外图像的多模态能见度深度学习方法.首先,利用图像配准获取视野范围与分辨率均相同的可见光-远红外输入图像对;然后,构造三分支并行结构的多模态特征融合网络;分别在可见光图像、远红外图像及其累加特征图中提取不同性质的大气特征,各分支的特征信息通过网络结构实现模态互补与融合;最后在网络末端输出图像场景所对应的能见度的等级.采用双目摄像机收集不同天气情况下的室外真实可见光-远红外图像作为实验数据,在不同性能指标、多角度下的实验结果表明,与传统单模态能见度深度学习模型相比,多模态能见度模型可显著提高小样本条件下能见度检测的准确率和鲁棒性.