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991.
Electrochemical synthesis of polypyrrole (PPy) film was achieved on mild steel (MS), in monomer containing 0.1 M phenylphosphonic acid solution. The synthesis was carried out using cyclic voltammetry technique. It was found that the electrode surface could only become completely passive, after a few successive cycles in solution of 0.1 M pyrrole + 0.1 M phenylphosphonic acid. Then, the thickness of polymer film was increased with help of successive cycles in a relatively narrower potential range. The corrosion performance of polymer coating was investigated in 3.5% NaCl solution, using electrochemical impedance spectroscopy (EIS) and anodic polarization curves. It was shown that the coating had high stability and low permeability, under such aggressive conditions. The EIS results also showed that the coating exhibited important anodic protection behaviour on mild steel. The percent protection efficiency value (E%) was found to be 98.4% and the percent total porosity value (P%) was determined to be 0.752%, after 96 h exposure time to corrosive solution. 相似文献
992.
Summary VX-478 belongs to a novel class of HIV-1 protease inhibitors that are based on N,N-disubstituted benzene sulfonamides. Force field parameters for the N,N-dialkyl benzene sulfonamide moiety have been assembled from the literature and from our own ab initio calculations. These parameters were employed to calculate solvation and binding free energy differences between VX-478 and two analogs. The free energy perturbation method has been used to determine these differences using two approaches. In the first approach, intergroup interaction terms only were included in the calculation of free energies (as in most reports of free energy calculations using AMBER). In the second approach, both the inter- and intragroup interaction terms were included. The results obtained with the two approaches are in excellent agreement with each other and are also in close agreement with the experimental results. The solvation free energies of N,N-dimethyl benzene sulfonamide derivatives (truncated models of the inhibitors), calculated using continuum solvation (AMSOL) methods, are found to be in qualitative agreement with the experimental and free energy perturbation results. The binding and solvation free energy results are discussed in the context of structure-based drug design to show how physicochemical properties (for example aqueous solubilities and bioavailabilities) of these HIV-1 protease inhibitors were improved, while maintaining their inhibitory potency. 相似文献
993.
In this paper, to keep scale inveriance, we propose an approximate M-estrmation for the mixed regression model and show consistency of the estimation under weaker conditions than that in [1]. 相似文献
994.
The effect of temperature on corrosion of copper in 0.1 M aqueous solution of potassium hydrogen phthalate (KHPh) has been investigated using polarization resistance technique. it was found that that the corrosion rate in the range 25–65°C obyes Vant Hoff's and Arrhenius Laws. The results indicate that corrosion of copper in KHPh is mainly cathodically controlled process. The polarization resistance decreases with rising the temperature in accordance with Stern-Geary equation. 相似文献
995.
A general procedure for the synthesis of NG-alkyl, and NG-aryl-L -arginines with relatively high overall yield is reported. The key step involved the coupling of protected L -ornithine 4 with isothiourea 7 to give the fully protected NG-aryl-L -arginine derivative 8 . Subsequent deprotection of 8 in acidic condition provided the final target compound 9 with an overall yield of more than 80%. 相似文献
996.
铜在离子选择性涂层下腐蚀行为的阻抗谱研究 总被引:1,自引:0,他引:1
用电化学交流阻抗技术研究了涂装不同离子造反性涂层的铜电极在3%NaCl溶液中的腐蚀行为,悄同涂装体系的阻抗谱特征,建立了相应的等 电路模型,由阻抗数据解析的结果,讨论了不同离子选择性涂层对铜的防蚀性能。 相似文献
997.
In this paper, we describe a variant of the Newton Interior-Point method in [8] for nonlinear programming problems. In this
scheme, the perturbation parameter can be chosen within a range of, values and we can use an iterative method for approximately
solving the reduced linear system arising at each step. We have devised the inner termination rule which guarantees the global
convergence of this Newton Inexact Interior-Point method. We remark that the required assumptions are weaker than those stated
in [8], as shown by some numerical examples.
This research was supported by the Italian Ministry for Education, University and Research (MIUR), FIRB Project No. RBAU01JYPN. 相似文献
998.
The specific adsorption of corrosion inhibitors (inorganic and organic compounds) was studied at a metal oxide (hematite)
in 0.5 mol dm–3 NaClO4 solution by an indirect radiotracer technique. This indirect radiotracer technique is based upon the application of labeled
indicator species, which were sulfate species at a concentration of 2×10–4 mol dm–3. The displacement of sulfate species was found in all the cases studied. The order of the inhibition efficiency of the corrosion
inhibitor molecules is in good agreement with the order of their adsorbabilities.
Electronic Publication 相似文献
999.
德摩根拓扑代数可度量化的一个充分条件 总被引:1,自引:0,他引:1
得出德摩根拓扑代数可度量化的一个充分条件 ,其结果将经典 Urysohn度量化定理以及模糊度量化定理作为其特例 相似文献
1000.
四元量化的综合鉴别函数滤波器实现比例不变相关识别 总被引:2,自引:2,他引:0
设计一种基于综合鉴别函数(SDF)的比例不变相关识别滤波器,将频域中被SDF调制的相关输出函数进行复数形式的四元量化(QFCQ),并采用叠代算法调整SDF的系数,使输出的相关峰尖锐,区分能力强,同时满足不同比例图像等相关峰输出的准则,从而达到了比例不变识别的要求.计算机仿真实验对属于训练图像系列的目标图像进行了识别,并与基本的SDF及二元化纯相位SDF做了比较,结果表明该方法具有较好的识别效果. 相似文献