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891.
Multiplex bead-array competitive immunoassay for simultaneous detection of three pesticides in vegetables 总被引:1,自引:0,他引:1
We report on a multiplex bead-based competitive immunoassay using suspension array technology for the simultaneous detection of the pesticides triazophos, carbofuran and chlorpyrifos. Three hapten-protein conjugates were covalently bound to carboxylated fluorescent microspheres to serve as probes. The amount of conjugates and antibodies were optimized. The new multi-analyte assay has dynamic ranges of 0.02–50 ng?mL?1, 0.5–500 ng?mL?1 and 1.0–1000 ng?mL?1 for triazophos, carbofuran and chlorpyrifos, respectively, and the detection limits are 0.024, 0.93 and 1.68 ng?mL?1. This new multiplex assay is superior to the traditional ELISA in possessing a wider detection range, better reproducibility and the feature of multi-target detection. Cross-reactivity studies indicated that the bead-array method is highly selective for the three target pesticides, and that individual analyses have no significant influence between each other, also without cross-reactions from other structurally related pesticides. The method was applied to analyze vegetables spiked with the three pesticides, and the recoveries were in ranges of 78.5–112.1 %, 72.2–120.2 % and 70.2–112.8 %, respectively, with mean coefficients of variation of <15 %. Figure
Schematic illustration of the multiplex bead-based competitive immunoassay 相似文献
892.
An inorganic–organic hybrid compound [Ni4(pzac)4(H2O)8(β-Mo8O26)]·2H2O (1), pzac = 2- pyrazinecarboxylic acid, was synthesized hydrothermally and characterized by IR spectrum, TGA, X-ray single-crystal diffraction. Photoluminescence property has been investigated. In 1 pzac coordinates to Ni1 with a chelating mode and bridges Ni2 forming a one-dimensional undulate chain structure. Ni atom accepts a terminal oxygen atom of [β-Mo8O26]4? anion with a little longer Ni–O distances of 2.685 Å and 2.767 Å. [β-Mo8O26]4? anion links four Ni atoms of four chains, forming a three-dimensional covalent framework. Lattice water molecules fill the vacancies of the framework. 相似文献
893.
毫米波圆柱波导自由电子激光放大器的数值模拟 总被引:1,自引:0,他引:1
本文以单粒子理论为基础,在不计空间电荷效应的近似条件下推导了带轴向引导磁场的三维圆柱波导非线性模拟方程组。用CAGFEL程序计算、分析了在带入口区、常数摇摆器条件下两组不同物理参数的自由电子激光放大器的物理模型。计算结果可靠,物理图象合理。对于其中的第二组参数还着重考查了光波频率、输入功率和摇摆器场振幅改变对输出功率和效率的影响。上述这些计算结果对0.7MeV 自由电子激光放大器的设计和实验具有一定的参考价值。 相似文献
894.
Differential scanning calorimetry (DSC) and x-ray diffraction (XRD) are employed to investigate the effects of nickel on the crystallization of the amorphous Zr70Cu20Ni10 alloy. We have found that the crystallization process of the amorphous Zr70Cu20Ni10 alloy is strongly influenced by the addition of nickel. Addition of 10 at% Ni to the Zr70Cu30 amorphous alloy makes the crystallization process proceed from a single-stage mode to a double-stage mode. The activation energy for crystallization of the amorphous Zr70Cu20Ni10 alloy is calculated to be about 388kJ·mol-1 on the basis of the Kissinger equation. The effects of nickel on the crystallization of the amorphous Zr70Cu20Ni10 alloy are discussed in terms of the genetics of metals. 相似文献
895.
We study the semi-classical ground states of the nonlinear Maxwell–Dirac system: $$\begin{aligned} \left\{ \begin{array}{l} \alpha \cdot \left( i\hbar \nabla + q(x)\mathbf{A }(x)\right) w-a\beta w -\omega w - q(x)\phi (x) w = P(x)g(\left| w\right| ) w\\ -\Delta \phi =q(x)\left| w\right| ^2\\ -\Delta {A_k}=q(x)(\alpha _k w)\cdot \bar{w}\ \ \ \ k=1,2,3 \end{array} \right. \end{aligned}$$ for \(x\in \mathbb{R }^3\) , where \(\mathbf{A }\) is the magnetic field, \(\phi \) is the electron field and \(q\) describes the changing pointwise charge distribution. We develop a variational method to establish the existence of least energy solutions for \(\hbar \) small. We also describe the concentration behavior of the solutions as \(\hbar \rightarrow 0\) . 相似文献
896.
897.
Dehydration of Castor Oil over NaHSO4/MCM‐41 Catalyst Modified by n‐Dodecyltriethoxysilane 下载免费PDF全文
Cui‐Xia Yan Jian‐Fei Ding Tian‐Lin Ma Rong Shao Wei Xu Jie He Peng‐Fei Wang 《无机化学与普通化学杂志》2017,643(12):772-779
n‐Dodecyltriethoxysilane (DTEOS) modified NaHSO4/MCM‐41 catalysts (silanized catalysts) were synthesized by different impregnation sequences and evaluated in the liquid‐phase dehydration of castor oil. The samples were evaluated by X‐ray diffraction, nitrogen adsorption‐desorption, SEM, TEM, FT‐IR spectroscopy, XPS, 29Si MAS NMR spectroscopy, contact angle measurements, NH3‐TPD, and pyridine‐FT‐IR spectroscopy. The analyses demonstrated that silanization enhanced the hydrophobicity of the catalysts, and the impregnation sequence of silanized catalysts had a significant effect on the NaHSO4 dispersion, surface area, acid distribution, and hydrophobicity of the silanized catalysts. The catalytic activity of the silanized catalysts was much higher than that of NaHSO4/MCM‐41. Among the silanized catalysts, the catalyst prepared by simultaneous impregnation with DTEOS and NaHSO4 showed the highest iodine value of 141.8 [g(I2) per 100 g] and lowest hydroxyl value of 11.3 [mg(KOH) · g–1]. 相似文献
898.
模糊层次分析法及其在优化建材连锁配送方案中的应用 总被引:12,自引:1,他引:12
本文首先说明模糊AHP方法是在传统的AHP方法的基础上,考虑到人们对复杂事物判断的模糊性,提出程度分析和综合决策理论,并介绍了模糊AHP方法的主要理论及步骤。最后把它用于建材连锁配送系统模式的评价,可将专家对诸方案指标体系所进行的带有模糊性判断,通过定量计算,转化为对连锁配送系统模式的排序,从而达到选优的目的。 相似文献
899.
Yu-Peng Tian Ming-Liang Zhang Zhang-Jun Hu Han-Mei Hu Jie-Ying Wu Xuan-Jun Zhang Sheng-Yi Zhang Xu-Tang Tao Min-Hua Jiang He-Ping Chen Suchada Chantrapromma Hoong-Kun Fun 《Transition Metal Chemistry》2005,30(7):778-785
A new Schiff base 4-[N-hydroxyethyl-N-(methyl)amino]benzaldehyde S-methyl dithiocarbazate (HL, where H is a dissociable proton) and the ruthenium complex [Ru(bpy)2L]PF6 (bpy = 2,2′-bipyridine) have been synthesized. The structural determinations of the ligand and its ruthenium complex, by
X-ray crystallography, show that the ligand is coordinated as a monoanionic bidentate N, S-donor, forming a four-member chelate
ring with a bite angle of 65.91°. The complex shows intense MLCT transitions in the visible region. Fluorescent and electrochemical
properties have been also studied. The complex in DMF solution exhibited a strong two-photon absorption (t.p.a.) at 532 nm
nanosecond laser pulses. The t.p.a. coefficient β, t.p.a. cross-section σ and the third-order optical nonlinearity χ(3) of the complex and the ligand have been determined by the Z-scan technique. 相似文献
900.