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Reforming of Methane by CO2 over Bimetallic Ni-Mn/γ-Al2O3 Catalyst 被引量:1
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作者 Anis Hamza Fakeeha Muhammad Awais Naeem +2 位作者 wasim ullah khan Ahmed Elhag Abasaeed Ahmed Sadeq Al-Fatesh 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2014年第2期214-220,I0004,共8页
γ-Al2O3 supported Ni-Mn bimetallic catalysts for CO2 reforming of methane were prepared by impregnation method. The reforming reactions were conducted at 500-700℃ and atmospheric pressure using CO2/CH4/N2 with feed ... γ-Al2O3 supported Ni-Mn bimetallic catalysts for CO2 reforming of methane were prepared by impregnation method. The reforming reactions were conducted at 500-700℃ and atmospheric pressure using CO2/CH4/N2 with feed ratio of 17/17/2, at total flow rate of 36 mL/min. The catalytic performance was assessed through CH4 and CO2 conversions, synthesis gas ratio (H2/CO) and long term stability. Catalytic activity and stability tests revealed that addition of Mn improved catalytic performance and led to higher stability of bimetallic catalysts which presented better coke suppression than monometallic catalyst. In this work, the optimum loading of Mn which exhibited the most stable performance and least coke deposition was 0.5wt%. The fresh and spent catalysts were characterized by various techniques such as Brunauer-Emmett-Teller, the temperature programmed desorption CO2- TPD, thermogravimetric analysis, X-ray diffraction, scanning electron microscope, EDX, and infrared spectroscopy. 展开更多
关键词 CH4 CO2 BIMETALLIC Dry reforming Ni/γ-Al2O3 Mn and H2/CO
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Flower Pollination Heuristics for Nonlinear Active Noise Control Systems 被引量:1
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作者 wasim ullah khan Yigang He +3 位作者 Muhammad Asif Zahoor Raja Naveed Ishtiaq Chaudhary Zeshan Aslam khan Syed Muslim Shah 《Computers, Materials & Continua》 SCIE EI 2021年第4期815-834,共20页
In this paper,a novel design of the flower pollination algorithm is presented for model identification problems in nonlinear active noise control systems.The recently introduced flower pollination based heuristics is ... In this paper,a novel design of the flower pollination algorithm is presented for model identification problems in nonlinear active noise control systems.The recently introduced flower pollination based heuristics is implemented to minimize the mean squared error based merit/cost function representing the scenarios of active noise control system with linear/nonlinear and primary/secondary paths based on the sinusoidal signal,random and complex random signals as noise interferences.The flower pollination heuristics based active noise controllers are formulated through exploitation of nonlinear filtering with Volterra series.The comparative study on statistical observations in terms of accuracy,convergence and complexity measures demonstrates that the proposed meta-heuristic of flower pollination algorithm is reliable,accurate,stable as well as robust for active noise control system.The accuracy of the proposed nature inspired computing of flower pollination is in good agreement with the state of the art counterpart solvers based on variants of genetic algorithms,particle swarm optimization,backtracking search optimization algorithm,fireworks optimization algorithm along with their memetic combination with local search methodologies.Moreover,the central tendency and variation based statistical indices further validate the consistency and reliability of the proposed scheme mimic the mathematical model for the process of flower pollination systems. 展开更多
关键词 Active noise control computational heuristics volterra filtering flower pollination algorithm
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一种新的荧光粉材料Ca8MgLu(PO4)7:Dy3+的制备及发光特性
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作者 谢飞燕 徐德康 +1 位作者 陈鸿雁 wasim ullah khan 《湖北大学学报(自然科学版)》 CAS 2019年第5期506-510,共5页
采用高温固相法合成一种黄色荧光粉Ca8MgLu(PO4)7 : Dy^3+,通过X线衍射(XRD)荧光光谱(PLE,PL)和荧光寿命研究Ca8MgLu(PO4)7 : Dy 3+的发光特性.在350 nm近紫外光激发下,荧光粉呈黄光发射,蓝光发射峰位于480 nm处(由4F9/2 → 6H15/2 跃... 采用高温固相法合成一种黄色荧光粉Ca8MgLu(PO4)7 : Dy^3+,通过X线衍射(XRD)荧光光谱(PLE,PL)和荧光寿命研究Ca8MgLu(PO4)7 : Dy 3+的发光特性.在350 nm近紫外光激发下,荧光粉呈黄光发射,蓝光发射峰位于480 nm处(由4F9/2 → 6H15/2 跃迁产生),黄光发射峰位于572 nm处(由4F9/2 → 6H13/2 跃迁产生),以黄光发射为最强.监测 572 nm 最强发射峰,激发光谱覆盖300500 nm,主激发峰位于350 nm.Ca8 MgLu(PO4)7: Dy 3+的热猝灭性能良好:在150 ℃下的发光强度积分是室温25 ℃的87.37%.研究结果表明Ca8MgLu(PO4)7: Dy^3+荧光粉材料有潜力应用于发光二极管(LED)中. 展开更多
关键词 荧光粉 Ca8MgLu(PO4)7: DY^3+ 白光LED 发光特性
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Bio-inspired heuristics hybrid with interior-point method for active noise control systems without identification of secondary path 被引量:1
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作者 Muhammad Asif Zahoor RAJA Muhammad Saeed ASLAM +1 位作者 Naveed Ishtiaq CHAUDHARY wasim ullah khan 《Frontiers of Information Technology & Electronic Engineering》 SCIE EI CSCD 2018年第2期246-259,共14页
In this study, hybrid computational frameworks are developed for active noise control(ANC) systems using an evolutionary computing technique based on genetic algorithms(GAs) and interior-point method(IPM), follo... In this study, hybrid computational frameworks are developed for active noise control(ANC) systems using an evolutionary computing technique based on genetic algorithms(GAs) and interior-point method(IPM), following an integrated approach, GA-IPM. Standard ANC systems are usually implemented with the filtered extended least mean square algorithm for optimization of coefficients for the linear finite-impulse response filter, but are likely to become trapped in local minima(LM). This issue is addressed with the proposed GA-IPM computing approach which is considerably less prone to the LM problem. Also, there is no requirement to identify a secondary path for the ANC system used in the scheme. The design method is evaluated using an ANC model of a headset with sinusoidal, random, and complex random noise interferences under several scenarios based on linear and nonlinear primary and secondary paths. The accuracy and convergence of the proposed scheme are validated based on the results of statistical analysis of a large number of independent runs of the algorithm. 展开更多
关键词 Active noise control (ANC) Filtered extended least mean square (FXLMS) Memetic computing Genetic algorithms Interior-point method
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