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51.
Sever Silvestru Dragomir 《Numerical Functional Analysis & Optimization》2013,34(5-6):487-491
A simple model optimal control problem for continuous casting with state-space constraints is approximated, as usual, by a penalty method and by a numerical discretization of the nonlinear heat equation. The convergence of the approximate problems directly to the original problem is proven under a stability criterion linking the penalty parameter with the discretization parameters. For this purpose, known discretization error estimates for the Stefan problem are extended for the case of time varying boundary conditions. 相似文献
52.
In this paper, the importance of molecular diffusion versus turbulent transport in the moderate or intense low-oxygen dilution (Mild) combustion mode has been numerically studied. The experimental conditions of Dally et al. [Proc. Combust. Inst. 29 (2002) 1147–1154] were used for modelling. The EDC model was used to describe the turbulence–chemistry interaction. The DRM-22 reduced mechanism and the GRI 2.11 full mechanism were used to represent the chemical reactions of an H2/methane jet flame. The importance of molecular diffusion for various O2 levels, jet Reynolds numbers and H2 fuel contents was investigated. Results show that the molecular diffusion in Mild combustion cannot be ignored in comparison with the turbulent transport. Also, the method of inclusion of molecular diffusion in combustion modelling has a considerable effect on the accuracy of numerical modelling of Mild combustion. By decreasing the jet Reynolds number, decreasing the oxygen concentration in the airflow or increasing H2 in the fuel mixture, the influence of molecular diffusion on Mild combustion increases. 相似文献
53.
Zhenglu Jiang 《Journal of statistical physics》2008,130(3):535-544
By combining the DiPerna and Lions techniques for the nonrelativistic Boltzmann equation and the Dudyński and Ekiel-Jeżewska
device of the causality of the relativistic Boltzmann equation, it is shown that there exists a global mild solution to the
Cauchy problem for the relativistic Boltzmann equation with the assumptions of the relativistic scattering cross section including
some relativistic hard interactions and the initial data satisfying finite mass, energy and entropy. This is in fact an extension
of the result of Dudyński and Ekiel-Jeżewska to the case of the relativistic Boltzmann equation with hard interactions.
This work was supported by NSFC 10271121 and the Scientific Research Foundation for the Returned Overseas Chinese Scholars,
the Ministry of Education of China, and sponsored by joint grants of NSFC 10511120278/10611120371 and RFBR 04-02-39026. 相似文献
54.
《Stochastic Processes and their Applications》2020,130(12):7547-7574
55.
56.
The effect of sodium carboxymethyl cellulose (Na-CMC) on the corrosion behavior of mild steel in 1.0 mol·L−1 HCl solution has been investigated by using weight loss (WL) measurement, potentiodynamic polarization, linear polarization resistance (LPR), and electrochemical impedance spectroscopy (EIS) methods. These results showed that the inhibition efficiency of Na-CMC increased with increasing the inhibitor concentration. Potentiodynamic polarization studies revealed that the Na-CMC was a mixed type inhibitor in 1.0 mol·L−1 HCl. The adsorption of the inhibitor on mild steel surface has been found to obey the Langmuir isotherm. The effect of temperature on the corrosion behavior of mild steel in 1.0 mol·L−1 HCl with addition of 0.04% of Na-CMC has been studied in the temperature range of 298–328 K. The associated apparent activation energy (E*a) of corrosion reaction has been determined. Scanning electron microscopy (SEM) has been applied to investigate the surface morphology of mild steel in the absence and presence of the inhibitor molecules. 相似文献
57.
Omar K. Jaradat Ahmad Al-Omari Shaher Momani 《Nonlinear Analysis: Theory, Methods & Applications》2008
In this paper we will study the existence and uniqueness of mild solution for the semilinear initial value problem of non-integer order:
where, α∈(0,1] and f(t,u(t),Gu(t),Su(t)) is a given function. 相似文献
u(α)(t)=Au(t)+f(t,u(t),Gu(t),Su(t)),
58.
Giuseppe Bartoli 《Tetrahedron letters》2008,49(16):2555-2557
A new protocol for the Knoevenagel condensation between β-diketones and aliphatic and aromatic aldehydes promoted by Mg(ClO4)2 under mild conditions is reported. 相似文献
59.
通过建立模型分析了近6年来的北京市高考试题。从试题水平来看,学生需要建立水溶液问题的基本认识角度和分析思路;从能力要求来看,部分试题实现了对关键能力的融合考查。在此基础上进行试题命制和施测,发现学生不能自主调用多个认识角度形成思路,提出了比较不同问题情境中的共同认识角度与建立“水溶液-平衡”二元分析模型的教学改进策略。 相似文献
60.
Hülya Kele Mustafa Kele lyas Dehri Osman Serinda 《Colloids and surfaces. A, Physicochemical and engineering aspects》2008,320(1-3):138-145
Electrochemical measurements were performed to investigate the effectiveness and adsorption behaviour of aminobiphenyl (Aph) and 2-(3-hydroxybenzylideneamino)biphenyl (Aph-S), as corrosion inhibitors for mild steel (MS) in 0.5 M HCl solution. Potentiodynamic polarization, linear polarization resistance (LP) and electrochemical impedance spectroscopy (EIS) techniques were applied to study the metal corrosion behaviour in the absence and presence of different concentrations of Aph and Aph-S. In order to gain more information about adsorption mechanism the AC impedance technique was used to evaluate the potential of zero charge (PZC) from polarization resistance (Rp) versus voltage (E) plot. Potentiodynamic polarization measurements showed that Aph act as cathodic type inhibitor where as Aph-S act mixed type. The inhibition efficiency (IE%) increases with increasing concentration of compounds and reached 92.6% for Aph and 97.2% for Aph-S at 5 × 10−3 M. Double layer capacitance (Cdl) and polarization resistance (Rp) values are derived from Nyquist plots obtained from AC impedance studies. The experimental data fit Langmuir isotherm for both Aph and Aph-S, and from the adsorption isotherm some thermodynamic data for the adsorption processes are calculated and discussed. The effect of exposure time on the corrosion behaviour of mild steel in the absence and presence of inhibitor over 168 h was also studied. 相似文献