某机载雷达发射校正系统的EMC设计

因受载机平台内电子设备电磁干扰的影响,某机载雷达发射校正时存在通道相位漂移的现象,表现为同一通道相位多次测量偏差超过正常幅度值.在阐述发射校正系统工作原理的基础上,深入分析干扰的来源和机理,提出了综合运用屏蔽、接地、滤波等措施解决电磁兼容问题的具体方法,实现了雷达发射校正系统的可靠工作,为该类工程设计提供了参考.     

Compatibility and Properties of Biodegradable Blend Films with Gelatin and Poly（vinyl alcohol）

The blend films with gelatin and poly（vinyl alcohol） （PVA） were prepared by a solution casting method. The compatibility between gelatin and PVA in the blend films was investigated. The transmittance, Fourier-transform infrared spectroscopy （FTIR）, x-ray diffraction （XRD）, thermogravimetry analysis （TG）, and differential scanning calorimetry （DSC） were employed to characterize the resultant blend films. According to optic result, the opacity of the blend film at the ratio of 20/80 （w/w, Gel to PVA） was the lowest, indicating the best compatibility between Gel and PVA at the ratio. The results oflR, XRD, DSC, and TG revealed an intensive interaction and good compatibility between them in the blend film at the ratio. The mechanical properties and solubility showed that PVA content in the blend films obviously affected the elongation at break and solubility. The mechanical properties and water resistance of gelatin film may be improved by the introduetion of PVA.     

Preparation and characterization of PEGDE crosslinked silk fibroin film

To obtain water-insoluble silk fibroin(SF) materials, polyethylene glycol diglycidyl ether(PEG-DE) was selected as a crosslinking agent to prepare SF films(blends). The reaction conditions were optimized for the crosslinking of the SF molecules. The hot water stability of the blends was measured using BCA protein assay and gravimetric analysis. The molecular conformation and crystalline structure of the blends were analyzed by FTIR and XRD, respectively. When the mass ratio of SF:PEG-DE was 1.0:0.8, the hot water loss rate of the SF blends was minimized. PEG-DE could induce SF molecules to form β-sheets during the gel reaction process, resulting in improved crystallinity and hot water dissolved resistance of the blend films. In order to demonstrate the cytotoxicity of the chemical reagents used to crosslink SF, L929 cells were seeded on the blend film(SF:PEG-DE = 1:1) and cultured for 3 days. Cells of L929 readily adhered and spread in the fusiform on the blend film resulting in high cell viability. The extracted liquid from the SF porous film did not inhibit cell proliferation, as estimated by the MTT assay.     

基于FDTD汽车点火系统电磁辐射的研究

电磁兼容是现代汽车设计中的关键及难点问题,点火系统是汽车内电磁辐射干扰的主要激励源,对点火系统电磁辐射计算方法的研究,是汽车电磁兼容问题研究的热点.在推导含电阻元件Yee元胞的时域有限差分法算式的基础上,构建了合理的激励源模式,借助AUTOCAD技术,建立了计算某型号汽车点火系统电磁辐射强度的时域有限差分法模型,并计算出了该型汽车点火系统高压导线在车内产生的辐射电场值.相关工作和结论对汽车电磁兼容问题的分析与预测具有一定的参考价值.     

高频大功率开关电源电磁兼容设计与实现

介绍了高频大功率开关电源电磁兼容设计方法,分析了开关电源产生电磁干扰的原因和解决方法。通过研制2800W移相全桥软开关DC/DC变换器,验证了解决电磁干扰方法正确性。该电源已应用在某重点项目中。     

基于三维溶度参数理论研究防老剂4020与橡胶间的相容性

采用三维溶度参数理论并借助计算机软件模拟计算了防老剂4020、天然橡胶（NR）、顺丁橡胶（BR）和丁苯橡胶（SBR）的三维溶度参数值,分别计算了防老剂4020与NR、BR和SBR之间的Flory-Huggins相互作用参数（χ）,并与防老剂4020的相容性实验结果进行对比,以预测防老剂与橡胶间的相容性。结果表明,三维溶度参数理论在表征防老剂4020与橡胶的相容性方面具有独特的优势,通过实验数据拟合,得到了防老剂4020的相容性与χ值之间的定量关系。     

Preparation and properties of Ce0.8Ca0.2O1.8 anode material by glycine-nitrate process

Ce0.8Ca0.2O1.8（CDC82） anode material was prepared by glycine-nitrate process（GNP）. Thermogravimetric（TG） analysis and differential scanning calorimetric（DSC） methods were adopted to characterize the reaction process of CDC82 material. X-ray diffractometry（XRD）, scanning electron microcopy（SEM）, direct current four probe （four-probe DC） and temperature process reduce（TPR） techniques were adopted to characterize the properties of CDC82 material. After the precursor was sintered at 750℃ for 4 h, CDC82 material with pure-fluorite structure and nanometer size was obtained. The total conductivity of CDC82 changes little with temperature in air at 50-850℃, and the maximum value is 0.04 S/cm at 750 ℃. The total conductivity wholly becomes larger when the atmosphere changes from air to hydrogen, which greatly increases with increasing temperature and reaches the maximum value of 1.09 S/cm at 850 ℃. Some impurities such as CeMg and La203 exist after the mixture of CDC82 anode and La1-xSrxGa1-yMgyO3-δ （LSGM） electrolyte material is sintered at 1 200 ℃ for 15 h. The CDC82 material as anode material has excellent catalytic property for hydrogen and methane.     

几种金属副在NaCl溶液中的抗蚀耐磨性能评价

应用电化学测试手段，针对20、2Cr13、QAl 9-2、QA l 10-3-15和QAl 10-4-4五种材料试件，分别测定了它们在NaCl溶液中的腐蚀电位及与QAl 9-2偶接时的电偶腐蚀电流的变化.并对几种铝青铜材料和QAl 9-2构成的摩擦副进行了摩擦磨损性能分析.结果表明，铝青铜材料的抗腐蚀性比钢好.其中QAl 10-4-4的腐蚀电位最为偏正，但它与QAl 9-2配副会对QAl 9-2产生较大的阳极电偶腐蚀；QAl 9-2与QAl 9-2相配时的电偶腐蚀最小，但其摩擦相溶性最差；而QAl 9-2与QAl 10-3-15材料副的抗电偶腐蚀能力和摩擦相溶性均佳.     

镀Cu-Ni的碳纤维及其复合材料SCIEI

用连续电镀法在碳纤维表面镀Cu后再镀Ni,制备了镀覆Cu-Ni双镀层的碳纤维,研究了Cu-Ni双镀层与碳纤维的高温相容性。并用镀Cu-Ni的碳纤维制备了Cu基复合材料,测试其弯曲强度、线热膨胀系数和电阻率。结果表明,Cu-Ni双镀层在高温下转变为面心立方的Cu-Ni固溶体,克服了在高温下Cu镀层的球化缩聚行为和Ni镀层对碳纤维的催化石墨化作用,且不影响碳纤维的拉伸强度。由于在界面上形成了可溶解微量碳的Cu Ni固溶体而增加了碳纤维与基体的结合强度,复合材料的弯曲强度显著增加,断口上的碳纤维拔出长度大为减小,复合材料的界面属于溶解结合型界面。     

片上集成光电微能源工艺兼容性及器件特性研究

根据暂存式光电微能源系统组成器件的制备工艺特点,提出了基于SOI晶片的光电微能源片上集成方案。主要工艺包括绝缘沟槽刻蚀、离子注入、氧化等,具有较好的制备工艺兼容性。另外,根据片上集成方案,对器件特性进行了研究。结果表明,光伏电池的转换效率为9.7%,NMOS管阈值电压、漏极反向击穿电压VT分别为0.98 V和31.97 V,NPN三极管的电流放大倍数、集电极-发射极之间击穿电压约为83 V和12 V。各器件特性满足系统工作要求,集成方案具有较好的可行性。