α-Fe2O3/Attapulgite-mediated reaction of benzyl chloride: Synthesis of poly(phenylene methylene)

Thermostable and fluorescent poly(phenylene methylene) (PPM) was synthesized via α-Fe₂O₃/attapulgite (α-Fe₂O₃/A)-mediated polymerization of benzyl chloride (BC) in CCl₄ in good yields. A carbocationic mechanism was proposed based on the controlling experiment. The structure and properties of PPM were characterized by Fourier transform infrared spectrometry, ¹H and ¹³C nuclear magnetic resonance spectrometry, thermogravimetric analysis, elemental analysis, gel permeation chromatography, and UV–vis and fluorescence spectrometry. The results show that PPM possesses outstanding homoconjugation fluorescence and excellent thermal stability with onset decomposition temperature of ca. 420 °C. Recycled α-Fe₂O₃/A proved to be still highly active for BC polymerization. Moreover, the strategy features low-cost and readily accessible starting materials, simple one-pot operation, and recyclable catalyst, facilitating future applications. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 2280–2285     

Correlation analysis of synchronization flow at a traffic bottleneck

In this paper, we study the correlation characteristics of synchronization flow in a two-lane model with the partial reduced lane based on the Kerner–Klenov–Wolf cellular automation model using the detrended fluctuation analysis (DFA). The local fundamental diagram and cross-correlation near the entry of the partial reduced lane have been analyzed in the periodic boundary condition. The typical two-dimensional scatter diagram in the local fundamental diagram and the noncorrelation of the cross-correlation between the local density and flow reveal characteristics of synchronization flow near the entry of the reduced lane. By the DFA, the synchronized flow at a traffic bottleneck exhibits the characteristics of long-range correlation. The results of investigation indicate that the injection rate, removal rate, and the location of the partial reduced lane have an obvious influence on the change of the scale exponent in the open boundary condition. Moreover, the length of the partial reduced lane has impact on the change of the scale exponent in the periodic boundary condition.     

Three cubic q-series of Gasper and Rahman

The Ramanujan Journal - New and elementary proofs for three cubic q-series transformations due to Gasper and Rahman (Am Math Soc 312:1, 1989; Can J Math 42, 1990) are presented by means of the Abel...     

Piezochromic luminescence and aggregation induced emission of 9,10- bis[2-(2-alkoxynaphthalen-1-yl)vinyl]anthracene derivatives

Four derivatives of 9,10-bis[2-(2-alkoxynaphthalen-1-yl)vinyl]anthracene (BNAs) were designed, successfully synthesized and characterized by spectrofluorometer, powder wide-angle X-ray diffraction (PXRD) and differential scanning calorimetry experiments (DSC), etc. It was found that these compounds exhibited aggregation-induced emission phenomenon. Moreover, these target compounds displayed reversible color change from yellow to orange upon pressing and annealing process. Interestingly, all of BNAs obviously presented red-shifted piezofluorochromic (PFC) properties and behaved mainly length dependence of alkoxy group, in which, BNA displayed the largest PFC spectral shift (Δl_PFC=26 nm). The PXRD profiles demonstrated the transformation from crystalline to amorphous state upon grinding, and the mechanism of PFC behaviors was proposed. Thus, changing the length of alkoxyl chain could be an alternative way to tune their PFC behaviors.     

Magnetic microparticle-based SELEX process for the identification of highly specific aptamers of heart marker--brain natriuretic peptide

Microchimica Acta - The brain natriuretic peptide (BNP) is known to be an effective indicator of heart failure. It has been widely adopted as a parameter for the evaluation of heart function of...     

Synthesis,characterization, and properties of regioregular conjugated polymers containing quaterthiophene and an acceptor repeating units

Novel donor–acceptor type polymers consisting of alternating quaterthiophene and an electron withdrawing moiety, pyrazinyl or pyridinyl, have been prepared using Stille coupling approach with moderate yields. The polymers were highly soluble in common organic solvents such as tetrahydrofuran and chloroform. The structure and optical properties of the polymers were characterized by NMR, UV‐vis and fluorescence spectroscopy, and cyclic voltammetry, respectively. The polymer having pyrazine unit exhibited a red‐shift in both absorption and emission in comparison with those analogs containing pyridine because of strong electron withdrawing character of the pyrazinyl group. The polymer containing pyrazinyl as acceptor units also depicted decrease in its optical and electrochemical bandgap relative to those polymers containing 2,5‐ or 2,6‐pyridine moieties. The electrochemical behavior showed facile n‐doping and p‐doping properties of those polymers consisting of alternating quaterthiophene and the acceptor moiety. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2163–2171, 2009