回归系数的混合估计与最小二乘估计的一个新的相对效率

本文对具有附加信息的线性回归模型中的混合估计与最小二乘估计给出了一种新的相对效率,研究了新的相对效率与其它几种相对效率的关系,得出了新的相对效率的上、下界.     

生长曲线模型中回归系数阵的极大似然估计的精确分布

对于生长曲线模型,基于理论发展和应用效果的考虑,本文引入了Gauss型误差．在此误差下,本文研究了模型中回归系数阵的极大似然估计的精确分布,求出了此分布的密度和特征函数．     

带松弛项的单个守恒律方程解的时态渐近性质

本文研究一维空间中带松弛项的单个守恒律方程解的大时间状态估计.在松弛项满足耗散条件下通过对线性化方程Green函数的逐点估计得到方程解在时间充分大时的衰减估计,并由此反映出“弱”惠更斯原理.     

Novel Fiberoptic Sensing Array an Fundamental Experiments

A suitable fiberoptic sensing array embedded in the smart structure to monitor quasi-distrbuted froces on the structrue in presented in this paper.Artificial neural networks are used in processing of fiberoptic sensing array signals.Fundamental experiments have been done and the results are also given.     

病态分析体系有偏估计的研究

运用广义岭估计和Ｌｉｕｋｅｊｉａｎ提出的有偏估计，对病态分析体系进行了数值模拟和实际光度测定，结果表明，广义岭估计显优于最小二乘估计，Ｌｉｕｋｅｊｉａｎ法有功效，可和为解析病态分析体系的化学计量学方法。     

具有超大通道结构的介孔氧化硅柱层状钛酸的合成和催化应用初探

A mesoporous (d=2.3mm) silica-pillared layered tetratitanate with a super gallery (d₀₀₁=1.84mm)was prepared by first preswelling layered tetratitanate with n-dodecyl amine, then reacting with 20wt% NH₂(CH₂)₃Si(OC₂H₅)₃ aqueous solution, and finally calcinating the resultant solid product in air at 550℃. All the reaction was carried out hydrothermally in an autoclave at 130℃. The obtained material has a relatively high BET surface area of 204m²·g^-1 and a thermal stability beyond 600℃. The catalytic application of the material was also investigated by using the dehydration of isopropanol and the reform of n-hexane as two probing reactions.     

排序集抽样下Inverse Rayleigh分布的Fisher信息量及其在参数估计中的应用

文章分别在简单随机抽样和排序集抽样下研究了Inverse Rayleigh分布中对应样本所含刻度参数θ的Fisher信息量.数值结果表示,同等样本容量的排序集样本比简单随机样本提供更多关于θ的信息.接着分别基于简单随机样本和排序集样本构造了θ的一些优良估计,并对估计结果进行了数值比较.     

Global Existence of Solutions and Lower Bound Estimate of Blow-Up Time for the Keller-Segel Chemotaxis Model北大核心CSCD

A macroscopic nonlinear Keller-Segel model for chemotactic cell migration was considered, where the existence region of the model is a bounded convex one on Ω ⊂ RN(N≥2). The global existence of the solution on Ω ⊂ R3 was obtained by means of the energy estimate method. The lower bound of the blow-up time was proved for N = 3 and N = 2. © 2022 Editorial Office of Applied Mathematics and Mechanics. All rights reserved.