具积分小系数的中立型微分方程的振动性

本文考虑一阶中立型时滞微分方程（1）的振动性，在的条件下建立了几个保证（1）振动的充分条件，所得结果推广了文献[6－7]的相应结果且改进了文[9][10]的相应定理．     

二氧化钛纳米管的制备与光催化活性

用阳极氧化法,室温条件下在含NH4F和H2O的电解液(丙三醇+NH4F+H2O;乙二醇+NH4F+H2O)中制备了TiO2纳米管阵列。用环境扫描电子显微镜(SEM)、X射线衍射仪(XRD)表征二氧化钛纳米管阵列的微观形貌和物相结构。在丙三醇电解液中,电压为60 V,65 V,70 V,75 V制备的纳米管直径依次为160、170、190、220 nm。对甲基橙(10 mg/L)降解测试TiO2纳米管阵列的光催化性能。研究结果表明:在100 V阳极电压制备经过500℃退火处理后的TiO2纳米管阵列的光催化效果最好,其光催化降解率在光照时间120 min时达到89.2%。     

PERIODIC SOLUTIONS AND STABILITY ANALYSIS FOR NEURAL NETWORKS WITH TIME-VARYING DELAY

1 IntroductionIt is well known that both in biological and man-made neural systems, inte-gl.ation afld communication delays are ubiquitous, and often become sources ofinstabilitY' The de1ays in electronic neural networks are usually time varying,and sometimes vary vio1ently with time due to the finite switching speed ofamplifiers and faults in the electrical circuit. They s1ow down the transmissionrate and tend to introduce some degree of instability in circuits. Therefore,fast response must …     

奇数阶中立型时滞微分方程的线性化振动性

考虑奇数阶中立型非线性微分方程ｄ＾ｎ／ｄｔ＾ｎ（ｘ（ｔ）－Ｐ（ｔ）ｇ（ｘ（ｔ－τ）））＋Ｑ（ｔ）ｈ（ｘ（ｔ－σ））＝０。本文在允许Ｐ（ｔ）－１振动的条件下给出了该方程的几个线性化振动结果。