The velocity difference control signal for two-lane car-following model

Based on single-lane traffic model, a two-lane traffic model is presented considering the velocity difference control signal. The stability condition of the model is obtained by the control theory. The delayed feedback control signal is added to the two-lane model, and the corresponding stability condition is derived again. The numerical simulations show that as the stability conditions are satisfied, the small disturbance will not amplify with and without control signal. In the meantime, the stability is strengthened as the control signal is considered. So the control signal would suppress the traffic disturbance successfully.     

Paper-based electrochemiluminescent 3D immunodevice for lab-on-paper, specific, and sensitive point-of-care testing

Recent research on microfluidic paper-based analytical devices (μPADs) has shown that paper has great potential for the fabrication of low-cost diagnostic devices for healthcare and environmental monitoring applications. Herein, electrochemiluminescence (ECL) was introduced for the first time into μPADs that were based on screen-printed paper-electrodes. To further perform high-specificity, high-performance, and high-sensitivity ECL on μPADs for point-of-care testing (POCT), ECL immunoassay capabilities were introduced into a wax-patterned 3D paper-based ECL device, which was characterized by SEM, contact-angle measurement, and electrochemical impedance spectroscopy. With the aid of a home-made device-holder, the ECL reaction was triggered at room temperature. By using a typical tris(bipyridine)ruthenium-tri-n-propylamine ECL system, this paper-based ECL 3D immunodevice was applied to the diagnosis of carcinoembryonic antigens in real clinical serum samples. This contribution further expands the number of sensitive and specific detection modes of μPADs.     

Two new compounds from the roots of Ilex pubescens

A new triterpenoid glycoside, heterobetulinic acid 3-O-β-D-glucopyranosyl(1?→?2)-β-D-xylopyranoside (1), together with a new phenylacrylic acid derivative, 3'S,4'-dihydroxyl-2'-methylene-but-1'-enyl caffeate (2), were isolated from the roots of Ilex pubescens. Their structures were elucidated by HR-ESI-MS, 1-D and 2-D NMR analyses and chemical methods. In addition, the absolute configuration of 2 was established by the application of a modified Mosher's method.     

Characterization of non-stoichiometric co-sputtered Ba0.6Sr0.4(Ti1???x Fe x )1?+?x O3???δ thin films for tunable passive microwave applications

The fabrication of novel iron-doped barium strontium titanate thin films by means of radio frequency (RF) magnetron co-sputtering is shown. Investigations of the elemental composition and the dopant distribution in the thin films obtained by X-ray photoelectron spectroscopy, Rutherford backscattering spectrometry, and time-of-flight secondary ion mass spectroscopy reveal a homogeneous dopant concentration throughout the thin film. The incorporation of the iron dopant and the temperature-dependent evolution of the crystal structure and morphology are analyzed by electron paramagnetic resonance spectroscopy, X-ray diffraction, Raman spectroscopy, atomic force microscopy, and scanning electron microscopy. In summary, these results emphasize the RF magnetron co-sputter process as a versatile way to fabricate doped thin films.     

Density estimated physicochemical properties of alanine-based ionic liquid [C7mim][Ala] and its application in selective transesterification of soybean oil

Amino acid ionic liquid (AAIL) based on alanine, 1-n-heptyl-3-methylimidazolium alanine ([C7mim][Ala]), has been prepared and characterized. Since the IL can form strong hydrogen bonds with water, trace amount of water is a problematic impurity in the IL. Using the standard addition method (SAM), the densities were measured in the temperature range from 293.15 to 343.15±0.05 K. On the basis of the experimental data of density, the surface tension , molar volume, and the molecular volume Vm, molar enthalpy of vaporization lgHm0, and the thermal expansion coefficients , for [C7mim][Ala] were estimated using semi-empirical methods. Also the interstice model has been verified with good accordance. Then the [C7mim][Ala] was taken as catalyst in the transesterification reaction with fatty acid, where soybean oil was used as raw material and methanol as reactant. The amount of catalyst, alcohol consumption, reaction time, temperature and other factors of the reaction were investigated. Using GC determination, the conversions were calculated by the internal standard method. The main ingredients of the products were identified by GC-MS as palm methyl ester and linoleic acid methyl ester only, which showed high selectivity in palmitic acid and linoleic acid.     

Reversible phase transition of the 1:1 complex between 18-crown-6 and n-propylammonium triiodide

Solid-state structure of the crystalline 1:1 complex [C 3 H 10 N(18-crown-6)] + [I 3 ](1) between 18-crown-6 and n-propylammonium triiodide has been determined at 293 and 93 K,respectively,showing a change from monoclinic P2 1 /m to monoclinic P2 1 /a.Crystal structural analysis shows that in addition to van der Waals’ forces,conventional N-H···O hydrogen bonds are the key interactions.Measurements of unit cell parameters versus temperature show that the values of one of the three axes and the crystal volume change abruptly and remarkably at 220 K,indicating a first-order phase transition.The lack of the mirror plane in the low temperature structure is the most important differences between the two structural forms.Differential scanning calorimetry(DSC) measurement confirms that 1 undergoes a reversible phase transition at about 220 K with a thermal hysteresis of 3.5 K.The relatively large latent heat makes 1 a good candidate for phase change materials.The phase transition is accompanied by an anomaly of dielectric constant during heating and cooling process near the phase transition temperature.     

Syntheses and Structures of Three Copper Coordination Polymers Based on Bis(triazol‐1‐ylmethyl)benzene

Three copper(II) coordination polymers [Cu(mbtz)₂(NCS)₂]_n ( 1 ), [Cu(mbtz)₂Cl₂]_n ( 2 ) and [Cu(mbtz)(btec)_0.5]_n ( 3 ) (mbtz=1,3‐bis(1,2,4‐triazol‐1‐ylmethyl)benzene, btec=1,2,4,5‐benzenetetracarboxylate) were synthesized. In 1 and 2 , two mbtz ligands are wrapped around each other and are held together by Cu(II) atoms to form one‐dimensional double chain. In 3 , each btec ligand connects four Cu(II) atoms through its four carboxylate groups, resulting in a planar two‐dimensional [Cu(btec)_0.5]_n network. The Cu(II) atoms are further coordinated mbtz ligands to fulfil their coordination geometry and construct new [Cu(btec)_0.5(mbtz)]_n network. 2 and 3 further form the three‐dimensional network through the π···π stacking interactions between the mbtz ligands. The thermal stabilities of 1 , 2 and 3 were measured.     

Electrochemical Immunosensor for α‐Fetoprotein Based on Gold Nanoparticles/Graphene‐Prussian Blue

The electrochemical immunosensor for α‐fetoprotein (AFP) was fabricated based on the platform of gold nanoparticles (GNP)/graphene (Gr)‐prussian blue (PB). By electrodeposition, GNP were modified on the surface of the prepared Gr‐PB. The anti‐AFP‐1,1′‐ferrocenedicarboxylic acid (FcDA) as label was directly immobilized on the platform of GNP/Gr‐PB. And after the immunoreactions, the formed complex inhibited the electron transfer and decreased the catalytic current of FcDA toward the reduction of H₂O₂. And in the range of 10–3200 pg·mL^?1, the decreased current is linear with the concentration of AFP, with a detection limit of 3 pg·mL^?1. The developed immunoassay method showed good precision, high sensitivity, acceptable stability and reproducibility, and could be used for the detection of real samples with consistent results in comparison with those obtained by the enzyme linked immunosorbent assay (ELISA) method.     

种子聚合法制备非球形聚合物颗粒的研究进展

十年前,光子晶体的需求促进了非球形颗粒的研究热潮。非球形颗粒由于其对称性下降,带来了新的性能和应用前景,成为当前材料领域研究的热点,得到了较广泛研究,目前其制备方法包括种子聚合法、自组装法、粒子聚集法、微流体法和机械拉伸法等。本文简述了种子聚合法的发展历程,介绍了种子聚合法制备非球形聚合物颗粒的相关机理,以种子微球材质分类综述了种子聚合法制备非球形聚合物颗粒的形貌和结构控制技术进展,概述了其潜在的应用领域,展望了可能的发展趋势。