利用界面层提高多孔铝阻尼能力的一种新方法

通过溶胶一凝胶法在多孔铝孔表面包覆一层厚度为100μm左右的聚苯乙烯薄膜。内耗测量表明，引入该界面层以后，多孔铝的阻尼能力有了非常显著的提高，甚至有了量级的变化。分析表明，借助界面层的微小滑移而耗能应该是阻尼能力提高的主要机制。同时也意味着利用有机高分子设计界面层从而提高相应多孔材料的阻尼能力是可行的、高效的。     

一道研究生入学试题的初等解法

最近,偶而翻阅了天津科学技术出版社出版的全国高等院校硕士学位入学试题解答《数学分析》一书后,受益匪浅.书中的某些试题完全可以用初等方法来解决,在这里仅以一例来说明. 在这本书中,四川师范学院1984年基础数学专业招生试题中有这样一道题,如果运用大学数学的专业知识去解此题,思想方法比较独特,一般不易掌握此类题的解题规律,如果我们     

Synthesis,Crystal Structure,Theoretical Studies and Sensitive Response toward Fe~(3+) of a Novel Tripyrazole Derivative Ligand

A novel pyrazole derivative ligand, BTA(BTA = bis-(4-ethoxy-phenyl)-[4-(tripyrazol-1-yl-methyl)-phenyl]-amine), was synthesized and fully characterized by 1H-NMR, MALDI-TOF-MS spectra and single-crystal X-ray diffraction analysis. It crystallizes in triclinic, space group P1, with a = 11.827(1), b = 16.000(2), c = 16.527(2), α = 108.510(1), β = 91.116(5), γ = 101.734(1)°, V = 2894.5(6) 3, Z = 1, Dc = 1.262 g/m3, F(000) = 1162, Μr = 545.63, μ = 0.083 mm-1, the final R = 0.0728 and w R = 0.2213 for 7541 observed reflections with I 2(I). The structural analysis revealed that three pyrazole units are attached to the same carbon atom connected with bis-(4-ethoxy-phenyl)-phenyl-amine group. UV-vis spectral features of the ligand in various solutions were explained by time dependent density functional theory(TD-DFT). It was also found that the ligand(BTA) exhibits an exclusively selective and sensitive response toward Fe3+ using UV-vis spectroscopic method.     

平衡损失下关于不等式约束的多元回归系数的容许估计

In this paper, the admissibility of multivariate linear regression coefficient with respect to an inequality constraint under balanced loss function is investigated. Necessary and sufficient conditions for admissible homogeneous and inhomogeneous linear estimators are obtained, respectively.     

以赤泥为原料合成聚合氯化铝铁复合絮凝剂及其应用

介绍了用炼铝废弃物赤泥制备聚合氯化铝铁絮凝剂（PAFC）的基本工艺.研究了液固比、反应温度、反应时间对赤泥溶出率的影响,确定了最佳溶出条件为反应液固比3.5∶1、温度85℃、时间1.5 h;制备聚合氯化铝铁絮凝剂的最佳工艺条件为铝铁摩尔比1∶1,温度60℃,反应时间1.0 h.通过对该产品进行混凝试验,得出当PAFC投加量为0.80 mL.L-1,沉降时间为30 min,pH在6～7之间时,浊度、色度、COD的最大去除率分别达到69%、85%、70%.     

聚赖氨酸抗菌肽改性明胶多功能水凝胶的构建与应用

将ε-聚赖氨酸(EPL)抗菌肽接枝到明胶上,合成ε-聚赖氨酸改性明胶(GEL-E)后,以GEL-E、羧甲基壳聚糖(CMC)和氧化硫酸软骨素(OCS)为原料,制备了一种具有可注射性、自愈合性及抗菌性的多功能快速凝胶化水凝胶——GEL-E/CMC/OCS水凝胶.该水凝胶具有较高的储能模量、弹性形变性能、自愈合性能、可注射性能以及抗菌性能.将甘草酸二钾(DG)载入水凝胶,赋予水凝胶抗炎特性以及促伤口愈合能力.初步评价了水凝胶的释药行为.结果表明,药物释放可达100%.同时,评价了载药后水凝胶的细胞相容性以及促细胞迁移能力,发现水凝胶对细胞的毒性很低,且可以促进细胞迁移.研究结果表明,该水凝胶具有良好的力学性能、生物相容性以及促细胞迁移能力,在促进伤口愈合领域具有广阔的应用前景.     

二元Bernstein-Durrmeyer算子的若干性质

对于[O,1]上的实值可积函数f,J.L.Durrmeyer引进一种新型的Bernstein算子其中这里 O≤x≤l,n=O,1,2,…在文[2]中,M.M.Derriennie又进一步讨论了它的逼近性质,在本文中,我们把M.M.Derriennie的某些结果推广到多元的情形,得到了一系列结果。     

由Laplace-stieltjes变换所定义的整函数的准确零(R)级和准确零(R)型

对于由Dirichlet级数所定义的整函数,J. F. Ritt[1],S. Mandelbrojt[2],余家荣[3],P. K. Jain[4]以及金忆丹[5]等人先后研究过它的(R)级和(R)型,准确(R)级和准确(R)型,得到了许多很好的结果。在文[6]中,余家荣又对由Laplace-stieltjes变换所定义的整函数引进了(R)级和(R)型的概念,推广了有关Dirichlet级数的结果。在本文中,我们对由Laplace-stieltjes变换所定义的整函数定义了它的准确零(R)级     

配位聚合物{[Zn(TSC)(MAL)]·H2O}n的制备及结构表征

The novel Zn^Ⅱ complex, {[Zn(TSC)(MAL)]·H₂O}_n (1), where TSC is thiosemicarbazide and MAL is malonate radicle, was synthesized by self-assembling from the reaction of stoichiometric zinc chloride, thiosemicarbazide and malonic acid in solution at pH 4.5~5.0. The structural and physicochemical properties were characterized by X-ray diffraction, infrared spectroscopy, electronic spectra and thermal analysis. The crystal data for the title coordination polymer: Monoclinic, P2₁/c, β=107.808(1)°, a=0.937 59(1) nm, b=1.110 83(1) nm, c=0.921 00(2) nm, Z=2, μ=2.919 mm^-1, R₁=0.039 0, wR₂=0.099 4. The structure feature is that the bridging dicarboxylates effectively link the zinc centers to form polymeric chain in a zig-zag way, which is stabilized by N-H…O, N-H…S and O-H…O hydrogen bonds. CCDC: 231861.