Multiferroic and magnetoelectric properties of La0.1Ba0.9Fe12O19 ceramics

La0.1Ba0.9Fe12O19 powders with similar hexagonal crystal structure to Ba Fe12O19 have been successfully synthesized using polymer precursor method. The powders were suppressed into pellets, which were sintered into ceramics at 1,300 °C for 1 h. The structure and morphology of the ceramics have been determined by X-ray diffraction（XRD） and field emission scanning electron microscopy（FESEM）. Clear electric hysteresis loops upon different amplitude of external fields indicates that La0.1Ba0.9Fe12O19 is a kind of possible ferroelectric compound. The maximum remnant polarization of La0.1Ba0.9Fe12O19 ceramic is estimated to be ＊9.6 l C/cm2. The Fe O6 octahedron in its perovskite-like hexagonal unit cell as well as the shift of Fe3？off the center of octahedron are proposed to be the origin of electric polarization in La0.1Ba0.9Fe12O19. Simultaneous occurrence of large ferroelectricity and strong ferromagnetism has been observed in La0.1Ba0.9Fe12O19 ceramics. More interestingly, this compound demonstrates electronic polarization behavior being actuated by an applied magnetic field, indicating the existence of magnetoelectric（ME） coupling effect in the La0.1Ba0.9Fe12O19 ceramics. Our results may lead to new device applications such as magnetically recorded ferroelectric memory.     

Ce0.9Gd0.1O19.5纳米粉的合成研究

分别采用柠檬酸一硝酸盐法,甘氨酸一硝酸盐法,碳酸盐共沉淀法制备了Ce0.9Gd0.1O19.5粉体。利用XRD、TG-DTA和FI-IR对粉体进行了表征,探讨了合成方法和烧结温度对掺杂CeO2米粉体粒径的影响。结果表明,烧结温度对粉体的粒径大小有较大的影响,采用碳酸盐共沉淀法合成的样品于500℃下焙烧2h后合成的掺杂CeO2粉体的颗粒最小。     

自动跟踪滤波器

介绍了一种滤除工频干扰的方法，它通过硬件电路实现了对工频频率的自动跟踪，从而解决了因工频的频率偏移而不易滤除的问题。     

LaNi5+TiFe0.9Mn0.1合金的贮氢性能

用冶炼法合成LaNi5 TiFe0.9Mn0.1复合贮氢合金,研究了LaNi5 TiFe0.9Mn0.1合金的贮氢性能。研究结果表明:由于TiFe0.9Mn0.1合金的加入,可有效地降低LaNi5的平台压力;当TiFe0.9Mn0.1的质量分数为15%左右时,放氢曲线中出现两个平台;TiFe0.9Mn0.1的质量分数趋于25%时,它的平台压力又逐渐升高,贮氢量逐渐增大,温度升高则第二个平台消失,贮氢量降低。该合金适用于低温贮氢。     

脑电信号混沌态的研究

对思维时的脑电信号混吨态进行了研究。在研究中首次引入了阵发性４０Ｈｚ脑电图检测技术借以确定用于混沌态分析的数据段，以确保分析结果的可靠性和稳定性。文中对混沌定量计算的参数也进行了一定研究，对３０多位受试者的脑电信号样本进行了分数维值和最大李亚谱诺夫指数计算。实验结果表明分数维值对临床应用确有价值，而仅凭一个最大的李亚谱诺夫指数似乎不能有助于诊断疾病。     

微波法合成Ni0.9V0.1Ox催化剂的研究

采用微波加热法制备了纳米Ni0.9V0.1Ox催化剂,并以BET、XRD、H2-TPR、电导测量等技术对催化剂进行表征,研究其对丙烷氧化脱氢制丙烯的催化性能.结果表明,采用微波法制备的Ni0.9V0.1Ox催化剂表现为p-型半导体性质,具有大比表面积和较好的低温催化活性,在375℃时,丙烷转化率为18.27%,丙烯选择性为56.9%.