Electrochemical impedance analysis of nanoporous TiO_2 electrode at low bias potential

<正>TiO_2 colloid was prepared by the sol-gel method and was bladed on transparent conduction glass to made nanoporous electrode. The impedance performance of TiO_2 electrode was studied at various bias potential.A simplified equivalent circuit was proposed to investigate the charge transport impedance of TiO_2 film and good fitting results were obtained.     

A supramolecular polymeric heterojunction composed of an all-carbon conjugated polymer and fullerenes

Herein, we design and synthesize a novel all-carbon supramolecular polymer host (SPh) containing conjugated macrocycles interconnected by a linear poly(para-phenylene) backbone. Applying the supramolecular host and fullerene C₆₀ as the guest, we successfully construct a supramolecular polymeric heterojunction (SPh⊃C₆₀). This carbon structure offers a means to explore the convex–concave π–π interactions between SPh and C₆₀. The produced SPh was characterized by gel permeation chromatography, mass spectrometry, FTIR, Raman spectroscopy, and other spectroscopies. The polymeric segment can be directly viewed using a scanning tunneling microscope. Femtosecond transient absorption and fluorescence up-conversion measurements revealed femtosecond (≪300 fs) electron transfer from photoexcited SPh to C₆₀, followed by nanosecond charge recombination to produce the C₆₀ triplet excited state. The potential applications of SPh⊃C₆₀ in electron- and hole-transport devices were also investigated, revealing that C₆₀ incorporation enhances the charge transport properties of SPh. These results expand the scope of the synthesis and application of supramolecular polymeric heterojunctions.

Herein, we design and synthesize a novel all-carbon supramolecular polymer host (SPh) containing conjugated macrocycles interconnected by a linear poly(para-phenylene) backbone.     

Shape-controlled solvothermal synthesis of bismuth subcarbonate nanomaterials

Much effort has been devoted to the synthesis of novel nanostructured materials because of their unique properties and potential applications. Bismuth subcarbonate ((BiO)₂CO₃) is one of commonly used antibacterial agents against Helicobacter pylori (H. pylori). Different (BiO)₂CO₃ nanostructures such as cube-like nanoparticles, nanobars and nanoplates, were fabricated from bismuth nitrate via a simple solvothermal method. The nanostructures were characterized by powder X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). It was found that the solvents and precursors have an influence on the morphologies of (BiO)₂CO₃ nanostructures. The possible formation mechanism of different (BiO)₂CO₃ nanostructures fabricated under different conditions was also discussed.     

Macroporous cellulose/carbon nanotube microspheres prepared by surfactant micelle swelling strategy for rapid and high-capacity adsorption of bilirubin

Cellulose - It remains a formidable challenge to construct high-performance haemoperfusion adsorbents with fast adsorption kinetic and high adsorption capacity for efficiently removing bilirubin...     

The wax deposition rate of water-in-crude oil emulsions based on the laboratory flow loop experiment

This paper aims to develop a mathematical model to predict the wax deposition rate of waxy crude emulsions, combining heat and mass transfer mechanisms. According to the flow loop experimental results, the wax deposition rate increases with the decreasing average temperature of oil/wall in a manner of linear regularity, and shows a downtrend with the increase of water cut due to diffusion resistance. An applicable model is developed regarding emulsion properties, radial temperature gradient, shear stress, and wax diffusion coefficient. In model validation, the prediction results are in good agreement with experimental data with the relative errors within 28.87%.     

Coacervation of copolymer of diallyldimethylammonium chloride and sodium styrenesulfonate aqueous solution

Coacervate behavior of polyelectrolyte complexes has been studied by many papers. Few studies have focused on the coacervate behavior of amphoteric polymer. In this study, amphoteric copolymer of diallyldimethylammonium chloride (DM) and sodium styrenesulfonate (SS) (the copolymer was noted as DMS) was synthesized with the mole content of SS to DM ranged from 0 to 10%. Firstly, DMS was characterized by static light scattering, FTIR, ¹H-NMR, TGA and DSC. Then, its phase and coacervate behaviors were studied. Turbidity was utilized as an indicator for the coacervate formation. It was found that when the SS content was more than 4 mol%, DMS coacervate would be formed in deionized water at a certain concentration. Temperature and pH have no effect on the formation of DMS coacervate. Meanwhile, salts has a great influence on the DMS coacervation. Unlike the results of the other polyelectrolyte complexes, Na₂SO₄, Na₂HPO₄, NaCOOCH₃, sodium citrate and NaI cannot prevent the DMS coacervate formation. However, the addition of NaCl, NaNO₃, NaBr and NaSCN can prevent the coacervate formation. The influence cannot be described by Hofmeister-like behavior. Results of surface tension and fluorescence spectrum presented that the driving forces to formation of DMS coacervate are the electrostatic interaction and the intermolecular hydrophobic interaction.     

多复变数完全拟凸映射的分解定理

设Ω_1C~(n1),Ω_2C~(n2)为凸的Reinhardt域,f(z,w)=(f1(z,w),f2(z,w))'为Ω_1×Ω_2上的正规化全纯映射.本文证明f为Ω_1×Ω_2上的正规化双全纯完全拟凸映射当且仅当 f(z,w)=(Φ_1(z),Φ_2(w))'其中φj:Ωj→C~(nj)是Ωj(j=1,2)上的正规化双全纯完全拟凸映射。     

小波分析中一个逆问题

本文证明:如果来自多尺度分析(伸缩因子为矩阵)的小波是标准正交的,那么相对应的尺度函数也是标准正交的,其中函数f_s(x)∈L~2(R~n)(s=1,2,…,r,r是正整数)的标准正交性是指f_s(x)的整平移所构成的函数族为L~2(R~n)的标准正交系。结果表明,如果我们想从多尺度分析出发构造正交小波,那么该多尺度分析必须有正交尺度函数。     

超塑成形/扩散连接过程的三维有限元模拟

采用Mindlin壳元,对SPF/DB工艺进行了模拟。利用罚函数方法,对板材自身接触问题进行分析,给出了接触板材间的接触力,并提出一种接触搜索判断方法,同时给出了算例。