Electrochemical investigation on the interaction of diclofenac with DNA and its application to the construction of a graphene-based biosensor

We have investigated the interaction between diclofenac and deoxyribonucleic acid (DNA) by the electrochemical method. On glassy carbon electrode, the voltammetric curve of diclofenac showed an oxidation peak, which was obviously influenced by the addition of DNA. Accordingly, a series of electrochemical experiments were carried out to elucidate the interaction between diclofenac and DNA. Based on the diclofenac–DNA interaction, a biosensor for diclofenac was developed. When a film of DNA was immobilized on the electrode surface, DNA showed an oxidation signal promoted by graphene oxide. Due to the diclofenac–DNA interaction, the peak current of DNA decreased and the peak potential shifted positively with increasing the concentration of diclofenac. The response of the biosensor was linear to the concentration of diclofenac in the range of 1 to 130?μM. Using such a biosensor, the photodegradation of diclofenac was successfully monitored.     

Determination of Toosendanin Extracted from Traditional Chinese Medicine: the Fruit of Melia azedarach LC–FD Detection

A rapid and selective reversed-phase liquid chromatography with fluorescence detection was developed and validated for the determination of toosendanin in the fruit of Melia azedarach. After extraction, the extracts were analysed at 25 °C using Eclipse XDB-C18 column (4.6 mm × 150 mm; 5 μm) and a mobile phase consisting of methanol–water at a flow rate of 1.0 mL min^?1. Detection wavelength was set at λ_Ex = 230 nm, λ_Em = 320 nm. The linearity, accuracy, and precision of the method were good, and the method can be successfully used to investigate the level of toosendanin component in herb samples with satisfactory results.     

Accurate Monte Carlo tests of the stochastic Ginzburg-Landau model with multiplicative colored noise

A accurate and fast Monte Carlo algorithm is proposed for solving the Ginzburg-Landau equation with multiplicative colored noise. The stable cases of solution for choosing time steps and trajectory numbers are discussed.     

Evaluation of a rapid method for the quantitative analysis of fatty acids in various matrices

A simplified method for quantitative analysis of fatty acids in various matrices by gas chromatography is proposed as an alternative to the conventional method and the variables of the protocol examined to optimize the processing conditions. The modified method involves direct methylation of fatty acids in homogenized samples with boron trihalide (BF(3) or BCl(3) in methanol) followed by extraction with hexane. The addition of hexane to the reaction mixture after the methylation process can enhance the efficiency of fatty acid methylation and is critical for those samples that contain high levels of triglycerides. A mechanism underlying this effect is proposed.     

Phenyltetraene-based nonlinear optical chromophores with enhanced chemical stability and electrooptic activity

"Push-pull" phenyltetraene-based chromophores are too sensitive to be incorporated into Diels-Alder-type cross-linkable polymers due to the reactivity of its diene segment with maleimides. A facile synthetic route has been explored to incorporate a methoxy group into the R position of such chromophores, which reduces their diene reactivity during the poling and lattice hardening process. The poled polymers with one of such chromophores doped in a cross-linked polymer lattice showed ultrahigh electro-optic activities, up to 306 pm/V at 1310 nm.     

Existence and asymptotic behavior of traveling wave solution for Korteweg-de Vries-Burgers equation with distributed delay

In this paper, we investigate the existence and asymptotic behavior of traveling wave solution for delayed Korteweg-de Vries-Burgers (KdV-Burgers) equation. Using geometric singular perturbation theory and Fredholm alternative, we establish the existence of traveling wave solution for this equation. Employing the standard asymptotic theory, we obtain asymptotic behavior of traveling wave solution of the equation.     

四注行波管周期永磁聚焦系统的优化设计

根据电子注参数、布里渊磁场公式及周期聚焦系统轴向磁通密度峰值经验公式,计算出永磁聚焦系统轴向峰值磁通密度,利用Ansoft Maxwell 3D软件建立了四注行波管周期永磁聚焦系统仿真模型,对模型结构尺寸进行了参数化分析,研究了周期永磁聚焦系统结构尺寸对聚焦系统通道内磁通密度的影响,确定了磁聚焦系统结构最佳尺寸配合,优化设计出了四注行波管周期永磁聚焦系统。其电子注通道中心轴线上轴向磁通密度峰值B_z=309 mT,横向磁通密度B_t=2.86 mT,B_t/B_z=0.92%。     

一种粒子谱仪用高均匀性高磁通密度永磁组件

研制的永磁组件采用主辅永磁体和匀场技术相结合的改进C型磁路结构,利用计算机仿真技术对组件磁路结构进行验证及优化。仿真分析及实验结果表明:采用这种磁路结构扩大了均匀区的范围,提高了磁场均匀性。按这种结构制造的永磁组件在20 mm气隙、中心平面200 mm120 mm均匀区内气隙磁通密度达到0.75 T,不均匀度为0.67%。另外,也对永磁组件在高低温下的磁性能进行了仿真计算,结果表明:在-55~70 ℃温度范围内均匀区的气隙磁通密度变化为4%左右。     

MgB2超导储能磁体可行性研究及结构优化

MgB2作为超导材料中的一颗新星,可以很好的应用于超导磁体。文中对比分析了作为超导磁体应用材料MgB2的超导特性,之后进行了MgB2磁体电磁设计。并通过与已有的Bi系超导磁体的对比,论证了MgB2在超导储能磁体应用中的可行性。针对MgB2超导特性进行磁体结构优化设计,得到两种新思路的螺管型磁体模型,都能够达到更好的经济性。     

不同幅值过电流下的高温超导线材失超发展过程

对高温超导材料的失超特性的研究是超导电力科学技术中的重要课题 ,为此 ,本实验室进行了大量的实验工作。在此基础上 ,文中整理了部分高温超导实验数据 ,对其进行分析和归纳总结 ,提出了高温超导线材失超三阶段理论