Magnetorheological suspension electromagnetic brake

The magnetorheological suspension (MRS) brake is of the monoblock type. The main part of the electromagnetic brake is an electromagnet, between whose poles two MRS disks are placed. For distances between disks of 0.65×10⁻³ m±10%, revolutions of the electric motor, coupled to the electromagnetic brake, ranging between 200 and 1600 rev/min and braking powers of up to 85 W, there are no differences in revolutions between the disks of the electromagnetic brake. For fixed revolutions of the electric motor, the revolution of the parallel disk can be modified continuously by means of the intensity of the magnetic field. In all cases, the quantity of MRS is of 0.35×10⁻³ kg.     

NUMERICAL STUDY ON THE SEDIMENTED MOTION CHARACTERISTICS OF THREE ALIGNED CIRCULAR PARTICLES IN THE INCLINED CHANNELS

主要应用浸没边界的格子玻尔兹曼方法（immersed boundary-lattice Boltzmann method, IB–LBM） 对处于不同倾斜角度通道内的三个刚体圆形颗粒在重力作用下下落的动力学特性进行了计算研究. 首先分析通道倾斜角度的影响, 结果显示当通道倾斜角处于59°90°的范围时会发生后一个颗粒超越前一个颗粒的现象. 其次, 研究了Re对颗粒沉降特性的影响, 结果表明Re 越大, 颗粒间发生聚集的时间越早. 研究还发现当3 个颗粒的直径大小不均匀时, 颗粒由大到小纵向依次排列, 或者出现中间小球直径较相邻两个小球直径大的排列情况, 均能促使颗粒加快聚集. 本文的研究结果可为环境工程及地质学中的颗粒沉降问题提供有价值的参考.     

Adsorption and photo-catalytic properties of layered lepidocrocite-like quasi-amorphous compounds based on modified potassium polytitanates

TiO2 compounds possess relatively high adsorption abilities and exhibit high photocatalytic activities that exhibit potential for the destruction of organic pollutants in natural and waste waters.Nanostructured potassium polytitanates modified using transition metals and their oxides/hydroxides generate new nanomaterials that operate in the visible spectral range.This study presents the synthesis and investigation of the structure,composition and photocatalytic activity of powdered nanoscale quasi-amorphous potassium polytitanates particles modified with iron,zinc,copper,cobalt and nickel sulfate in aqueous solutions.All of the powders investigated in this work exhibit a high adsorption capacity for methylene blue dye（15-20mg/g） related to the welldeveloped surface of the layered potassium polytitanate particles.Introducing transition metals and their oxides/hydroxides influences the electronic structure of the obtained systems.A high photocatalytic activity was observed for systems containing iron,zinc,nickel and their oxides/hydroxides in the ultraviolet and visible ranges.     

Ratchet transport of self-propelled chimeras in an asymmetric periodic structure

We studied the rectified transport of underdamped particles subject to phase lag in an asymmetric periodic structure. When the inertia effect is considered, it is possible to observe reversals of the average velocity with small self-propelled force, whereas particles always move in the positive direction with large self-propelled force. The introduction of phase lag leads particles to follow circular orbits and suppress the polar motion. In addition, this can adjust the direction of particle motion. There exists an optimal value of polar interaction strength at which the rectification is maximal. These results open the way for many application processes, such as spatial sorting of particles mixture and separation based on their physical properties.     

Identification of active compounds from medicinal plant extracts using gas chromatography-mass spectrometry and multivariate data analysis

Conventional methods of drug discovery from natural products include bioassay-guided fractionation, which is tedious and has low efficiency. The aim of this work is to develop a platform method to rapidly identify bioactive compounds from crude plant extracts and their partially purified fractions using multivariate data analysis (MVDA). Soxhlet extraction and liquid-liquid fractionation were used to prepare different extracts and fractions from the leaves of a medicinal plant, Ardisia elliptica. The extracts and fractions were analysed chemically using GC-MS, and their ability to inhibit platelet aggregation was investigated. Two MVDA methods were developed and optimised to analyse the results. In the first method, compounds with the highest contribution scores for biological activity calculated by different models were listed as potential antiplatelet compounds. For the second MVDA method, a correlation of the concentrations of constituents and biological activities in the various extracts and fractions for each compound was done. Compounds with the highest correlation coefficients were identified as potential antiplatelet compounds. One of the predicted components was isolated, purified and confirmed to possess antiplatelet effects. This platform method can be developed and optimised for other plant extracts and biological activities, thus reducing time and cost of drug discovery while improving efficiency.     

固体粒子对板式膜吸收过程的传质强化

分别采用纯CO2-去离子水和不同浓度的NaOH溶液为实验体系,在板式膜器中研究了第三相固体粒子对膜吸收过程传质效果的影响．分别考察了在不同粒子种类、搅拌转速、传质体系、化学反应强度、膜孔隙率等因素下固体粒子对传质强化的影响．结果表明,随着粒子固含率的增大,传质系数和增强因子均有所提高,当粒子固含率增大到一定范围后,传质系数和增强因子的变化趋于平缓．在固含率一定的条件下,不同种类的固体粒子对膜吸收过程的强化效果随着固体粒子密度的增加而减小．传质系数随着搅拌转速的增大而增大,但高搅拌转速下固体粒子的强化作用减弱．膜吸收过程的传质系数和增强因子随着化学反应强度的增强而增加．随着粒子固含率的增大,不同膜孔隙率对传质效果的差异减小,且孔隙率越小,固体粒子对膜吸收传质过程的强化效果越好．其中,对于纯CO2-去离子水体系,当孔隙率为20％,粒子固含率为1．5gL^（-1）时,固体粒子的加入可使传质系数提高1．45倍,增强因子可达2．45．     

Exploring the binding mechanism of thioflavin-T to the β-amyloid peptide by blind docking method

Using blind dock method,we find that thioflavin-T(ThT) can bind to both monomers and fibrils of the full-length β-amyloid peptide(Aβ1-42) and has a higher binding affinity to the fibrils.It is shown that the hydrophobic interaction between the ligand(ThT) and substrate(Aβ1-42) are stronger than hydrogen bonds.Furthermore,ThT tends to be located near the C-terminus of Aβ monomer through hydrophobic and electrostatic interactions,while it tends to contact the residues Met35 and Gly27 of the fibril surface mainly through hydrophobic interaction.Finally,according to the docking results and ThT fluorescence assay,a kinetic equation is proposed to deduce the aggregation rate coefficient of Aβ1-42.     

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。