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71.
Comparative Study of Carbon Paste,Screen Printed,and PVC Potentiometric Sensors Based on Copper‐sulphamethazine Schiff Base Complex for Determination of Iodide – Experimental and Theoretical Approaches 下载免费PDF全文
New poly vinyl chloride (PVC) membrane, carbon paste (CP), and screen printed (SP) electrodes are constructed for iodide sensing. They are based on copper (II)‐sulphamethazine Schiff base complex as suitable carrier. Mechanism was proved by FT‐IR and UV‐Vis spectroscopy. Computational study involving binding energies calculations at DFT/B3LYP level of theory confirmed the proposed mechanism and agreed the observed selectivity pattern. Responses are near‐Nernstian (?55.0, ?51.0 mV/concentration decade) for PVC, and SP electrodes, and super‐Nernstian (?61.2 mV/concentration decade) for the CP electrode. Lower limit of detection (3.2×10?6 mol L?1) and improved selectivity over the highly interfering thiocyanate were obtained in comparison with the previously reported Schiff base complexes‐based iodide sensors. 相似文献
72.
用MirrorOp推屏软件或"推送宝"等设备,可以实现将手机或平板电脑显示屏向投影屏幕的实时推送。这种跨平台同屏显示技术,可以解决化学教学中的某些现实问题,由此带来的教师课堂自由度的改善,有利于缓解多媒体教学中的"互动性缺乏"问题。 相似文献
73.
Akhtar Hayat Amina Rhouati Rupesh K. Mishra Gustavo A. Alonso Muhammad Nasir Georges Istamboulie 《International journal of environmental analytical chemistry》2016,96(3):237-246
Herein, we reported a titanium oxide (TiO2) modified activated carbon nanocomposite that showed advantageous characteristics in terms of electro-conductivity, catalytic activity and surface area. The designed nanocomposite was employed to modify the screen printed carbon electrode transducer surface in the construction of an electrochemical sensor. The electrode surface modification was characterised by cyclic voltammetry and impedimetric studies. The modified transducer surface was subsequently used for the detection of four phenolic endocrine disruptors, p-nitrophenol, hydroquinone, catechol and 1-naphtol. Under optimal conditions, TiO2 modified activated carbon sensor was evaluated by differential pulse voltammetry showing a good linearity with correlation coefficients higher than 0.99. It showed, in parallel, a high sensitivity where the detection limits were 348 ng/L, 110.1 ng/L, 3.3 ng/L and 7.2 µg/L for the respective studied compounds (S/N = 3). Finally, we validated the method with river water samples, and good recovery values were obtained showing the potential application of the reported biosensor. 相似文献
74.
75.
This study presents characteristic‐based split (CBS) algorithm in the meshfree context. This algorithm is the extension of general CBS method which was initially introduced in finite element framework. In this work, the general equations of flow have been represented in the meshfree context. A new finite element and MFree code is developed for solving flow problems. This computational code is capable of solving both time‐dependent and steady‐state flow problems. Numerical simulation of some known benchmark flow problems has been studied. Computational results of MFree method have been compared to those of finite element method. The results obtained have been verified by known numerical, analytical and experimental data in the literature. A number of shape functions are used for field variable interpolation. The performance of each interpolation method is discussed. It is concluded that the MFree method is more accurate than FEM if the same numbers of nodes are used for each solver. Meshfree CBS algorithm is completely stable even at high Reynolds numbers. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
76.
舰船光电对抗中烟幕遮蔽与激光引偏的配合作战研究 总被引:1,自引:1,他引:0
通过分析舰船光电对抗作战中烟幕干扰和激光引偏干扰的特点,提出了烟幕遮蔽和激光引偏在对抗半自主激光制导武器时配合使用的作战样式,分析了各种作战样式的使用条件、工作流程和配合要素,以及作战样式的优势与不足,指出了多种干扰手段配合作战是发挥光电对抗系统综合对抗效能的关键. 相似文献
77.
78.
The toughness of a (noncomplete) graph G is the minimum value of t for which there is a vertex cut A whose removal yields components. Determining toughness is an NP‐hard problem for general input graphs. The toughness conjecture of Chvátal, which states that there exists a constant t such that every graph on at least three vertices with toughness at least t is hamiltonian, is still open for general graphs. We extend some known toughness results for split graphs to the more general class of 2K2‐free graphs, that is, graphs that do not contain two vertex‐disjoint edges as an induced subgraph. We prove that the problem of determining toughness is polynomially solvable and that Chvátal's toughness conjecture is true for 2K2‐free graphs. 相似文献
79.
令ΛA_1,Λ_2为两个环,M是(A_2-Λ_1)-双模,且N是(Λ_1-Λ_2)-双模.六元组Γ=(Λ_1,Λ_2,N,M,ψ,φ)是一个森田六元组.对于Γ的表示,确定其几乎分裂序列(也称AR-序列)是非常重要的.通过modΛ_1和modΛ_2的右(左)几乎分裂同态、既约同态构造Γ上的相应同态,并进一步确定它的几乎分裂序列. 相似文献
80.
In this article, we introduce two least‐squares finite element procedures for parabolic integro‐differential equations arising in the modeling of non‐Fickian flow in porous media. By selecting the least‐squares functional properly the presented procedure can be split into two independent subprocedures, one subprocedure is for the primitive unknown and the other is for the flux. The optimal order convergence analysis is established. Numerical examples are given to show the efficiency of the introduced schemes. © 2012 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2013 相似文献