聚对苯二甲酸乙二酯微流控芯片的制备和表面改性

高聚物微流控芯片具有制备简单、成本低、可批量生产等突出优点而有望成为一次性器件,近年来在国内外引起了同行们的兴趣.但是,高聚物表面的憎水性、对有机分子的强吸附性、电渗流的不稳定性等又成为高聚物芯片在微流控分析领域得以广泛应用的障碍.表面改性是改善高聚物芯片分析特性的有效途径.     

利用高炉水淬渣制备(Ca/Y)-α-Sialon陶瓷的组织与性能

以高炉水淬渣合成的Ca-α-Sialon粉体为原料采用无压烧结技术制备了（Ca/Y）-α-Sialon陶瓷。通过用排水法、三点弯曲实验法、金相显微镜法、XRD法等手段研究了（Ca/Y）-α-Sialon陶瓷的烧结致密化过程、材料的力学性能、显微组织、相组成和材料的断裂特征。结果表明,适量的Y2O3促进材料的烧结致密化和提高材料的力学性能,但Y2O3过量（大于10%）时对材料的烧结和力学性能不利。掺杂Y^3＋的（Ca/Y）-α-Sialon呈柱状晶,随着Y2O3含量的增加和烧结温度的提高,（Ca/Y）-α-Sialon呈柱状晶出现粗化和等轴化。含10%Y2O3的材料在1700℃烧结时可获得较高的力学性能。     

Chemiluminescence sensor for isoniazid with controlled-reagent-release technology

A novel chemiluminescence (CL) sensor for isoniazid combined with flow-injection technology is presented in this paper. The analytical reagents, luminol and ferricyanide, were both immobilized on an anion-exchange column. The CL signal produced by the reaction between luminol and ferricyanide, which were eluted from the column through sodium phosphate injection, was decreased in the presence of isoniazid. The decreased CL intensity was linear with isoniazid concentration in the range 0.001–1.0 μg·ml⁻¹; and the detection limit was 0.35 ng·ml⁻¹ (3s). The whole process, including sampling and washing, could be completed in 2 min with a relative standard deviation of less than 4.1%. The sensor could be reused more than 400 times and has been applied for the determination of isoniazid in pharmaceutical preparations.     

含铈不锈钢的抗菌性能

以00Cr18Ni9不锈钢成分为基础,添加0～5%的稀土元素铈（Ce）.利用电子探针分析了加铈（Ce）不锈钢中Ce的分布;用化学分析法测定了含铈不锈钢中铈（Ce）和碳（C）的含量;用X射线衍射方法测试了含铈（Ce）不锈钢中铈（Ce）的析出相成分;采用贴膜法测试了含Ce不锈钢对大肠杆菌ATCC 8099、金黄色葡萄球菌ATCC 6538的抗菌性能.结果表明： 含Ce不锈钢具有优异的抗菌性能,与含Cu抗菌不锈钢相比,含Ce不锈钢无需时效热处理就具有优异的抗菌性能.并讨论了含Ce不锈钢的抗菌机制.     

基于金属介导和离子液体的新型绿原酸印迹整体柱的制备及评价

选用1-乙烯基-3-乙基咪唑四氟硼酸盐([VElm]BF4,一种离子液体)作为功能单体,以Co2+为介导离子,结合1-丁基-3-甲基咪唑四氟硼酸盐([BMIM]BF4)/二甲基亚砜(DMSO)二元致孔体系制备了绿原酸印迹整体柱。经过对制备参数的考察,确定最佳比例为绿原酸:Co2+:[VElm]BF4:EDMA(乙二醇二甲基丙烯酸酯)(摩尔比)=1:1:5:20,[BMIM]BF4:DMSO=3:1(V/V),最大印迹因子达2.10。通过优化色谱条件,最终在乙腈:20 mmol/L乙酸钠缓冲液(pH 4.2)=70:30(V/V)时实现了绿原酸及其类似物的完全分离。由此可见,以离子液体为功能单体及致孔剂,在金属介导策略下制备的分子印迹聚合物可实现绿原酸的特异性识别及分离。     

Effects of Cone Angles on Nonlinear Vibration Responses of Functionally Graded Shells北大核心CSCD

The nonlinear vibration responses of functionally graded materials (FGMs) shells with different cone angles under external loads were studied. Firstly, the Voigt model was employed to describe the physical properties along the thickness direction of FGMs conical shells. Then, the motion equations were derived based on the 1st-order shear deformation theory, the von Kármán geometric nonlinearity and Hamilton’s principle. Next, the Galerkin method was applied to discretize the motion equations and the governing equations were simplified into a 1DOF nonlinear vibration differential equation under Volmir’s assumption. Finally, the nonlinear motion equations were solved with the harmonic balance method and the Runge-Kutta method, and the amplitude frequency response characteristic curves of the FGMs conical shells were obtained. The effects of different material distribution functions and different ceramic volume fraction exponents on the amplitude frequency response curves of conical shells were discussed. The bifurcation diagrams of conical shells with different cone angles, as well as time process diagrams and phase diagrams for different excitation amplitudes, were described. The motion characteristics were characterized by Poincaré maps. The results show that, the FGMs conical shells present the nonlinear characteristics of hardening springs. The chaotic motions of the FGMs conical shells are restrained and not prone to motion instability with the increase of the cone angle. The FGMs conical shell present a process from the periodic motion to the multi-periodic motion and then to chaos with the increase of the excitation amplitude. © 2022 Editorial Office of Applied Mathematics and Mechanics. All rights reserved.     

一些稀疏图的强边染色（英文）

图G的强边染色是指对图G进行正常边染色使得任意长度为3的路的三条边染不同的颜色.图G的强边色数,记为χ’_s(G),是使得图G是强k边着色的最小正整数kk.2015年,Zang [arXiv:1510.00785]证明了:最大度△(G)=5的图G,χ’_s(G)≤37.本文证明了:最大度△(G)=5且最大平均度小于8/3(或者14/5)的图G,χ’_s(G)≤13 (或者14).另外,本文证明了:最大度△(G)≥3的不含K_2,3-图子式的图G,χ’_s(G)≤4△(G)-6,这个界是紧的.     

FTIR studies of vitamin E-cholesterol-DPPC membrane interactions in CH2 region

Binary and ternary mixtures of alpha-tocopherol (alphaT), cholesterol and dipalmitoyl phosphatidylcholine (DPPC) in the form of multilamellar liposomes have been investigated by Fourier Transform Infrared Spectroscopy (FTIR). Investigation of frequencies, bandwidths and band shapes of CH(2) stretching and scissoring bands indicate that the effect of alphaT is dominant in comparison with cholesterol and alphaT decreases the interaction of cholesterol with phospholipid membranes.     

Synthesis of vinca alkaloids and related compounds. 100. Stereoselective oxidation reactions of compounds with the aspidospermane and quebrachamine ring system. First synthesis of some alkaloids containing the epoxy ring

The first syntheses of the alkaloids (-)-mehranine (3), (+)-voaphylline/conoflorine (4), (+)-N(a)-methylvoaphylline/hecubine (5), and (-)-lochnericine (2) were achieved by stereoselective epoxidation starting from (-)-tabersonine (1), through intermediates with the aspidospermane and quebrachamine skeleton.     

光学薄膜氧气传感器研究进展

光学薄膜氧气传感器具有检测精度高、选择性好、抗干扰能力强等优点,近年来日益得到人们的广泛重视,研究工作也在不断深化和拓展,展现出十分广阔的应用前景。本文按光学薄膜氧气传感器的制备方法分类扼要综述了光学薄膜氧气传感器的研究现状,并展望了其研究前景。