检索结果-南通市图书馆

Fe-Promoted Copper Oxide Thin-Film Catalysts for the Catalytic Reduction of N_(2)O in the Presence of Methane

Journal of Thermal Science 2023年第2期32卷 531-541页

作者： muhammad waqas WU Lingnan EI KASMI Achraf muhammad Ammar TIAN Zhenyu Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Department of Mechanical Engineering College of Engineering and TechnologyUniversity of SargodhaSargodha 40100Pakistan Laboratory LSIA UAE/U02ENSAHNational School of Applied Sciences of Al HoceimaAbdelmalek Essaadi UniversityAl Hoceima 32003Morocco Department of Chemical Engineering Technology Government College UniversityFaisalabad 38000Pakistan

Thin-film catalysts are recently recognized as promising catalysts due to their reduced amount of materials and good catalytic activity,leading to low-cost and high-efficiency catalysts.A series of CuFeO_(x)thin-film catalysts were prepared with different Fe contents using a one-step method as well as tested for the catalytic reduction of nitrous oxide(N_(2)O)in the presence of CH_(4)at a high GH SV of 185000 mL/(g·h).The increase of iron strongly affects the dispersion and leads to the creation of a less-active segregated Fe_(2)O_(3)phase,which was confirmed by XRD,EDX,and XPS *** results show that the synergistic properties between Cu and Fe,which affect the CuFeOxfilm catalysts in many aspects,such as the hollow-like texture,specific surface area,nano-crystallite size,the surface contents of Cu^(+),Fe^(3+),and oxygen species,the reductive strength and the strong active sites on the *** DFT calculations,the adsorption and decomposition energy profiles of N_(2)O on the CuFeO_(2)(012)surface model were *** surface Fe-site and hollow-site are active for N_(2)O decomposition,and the decomposition energy barriers on the Fe-site and the hollow-site are 1.02 eV and 1.25 eV respectively at 0 *** strategy adopted here to tailor the activity through low-doping Fe-oxide catalysts could establish a promising way to improve the catalytic reduction of N_(2)O with CH_(4).

关键词： catalytic reduction thin-film catalysts doping strategy density functional theory calculations N_(2)O decomposition

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of Firing Temperature on the Electromagnetic Properties of Electronic Transformer Cores Developed by Using Nanosized Mn–Zn Ferrite Powders

引用

Acta Metallurgica Sinica(English Letters) 2015年第2期28卷 159-163页

作者： Hassan waqas Ammad Hussain Qureshi muhammad Shahzad Materials Division Directorate of Technology PINSTECH

Current investigation deals with the effect of grain growth process as a function of sintering temperature on the electromagnetic properties （initial permeability, impedance, and gain） of Mn-Zn ferrite （MZF） cores （toroids）. By employing auto combustion process, nanosized [（20 ± 5） nm] MZF powders were synthesized and toroid shape cores were obtained after subsequent calcination and firing （sintering） process. It was observed that the submicron structure （0.5 μm） achieved in the ferrite core sintered at 1,000 ℃ was gradually transformed into micron size grains by increasing the firing temperature i.e., 1,100, 1,200, and 1,350 ℃. The results reveal that MZF core sintered at low temperature （1,000 ℃） showed high impedance, low initial permeability, and narrow working frequency range i.e., 3-15 MHz. However, the improvement in initial permeability, sintered density, and operational frequency range （100 kHz-17 MHz） was observed at high temperature （1,350 ℃） firing in the inert environment. This synthesized MZF core is more suitable for miniaturized switch mode power supply applications.

关键词： Mn-Zn ferrites Nanosized powders Impedance Sintering

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Thermo-bioconvection transport of nanofluid over an inclined stretching cylinder with Cattaneo–Christov double-diffusion

引用

Communications in Theoretical Physics 2021年第7期73卷 47-58页

作者： Hassan waqas Umair Manzoor Taseer muhammad Sajjad Hussain Department of Mathematics Government College University FaisalabadLayyah Campus 31200Pakistan Department of Mathematics College of SciencesKing Khalid UniversityAbha 61413Saudi Arabia Mathematical Modelling and Applied Computation Research Group(MMAC) Department of MathematicsKing Abdulaziz UniversityPO Box 80203Jeddah 21589Saudi Arabia

In this paper,Newtonian nanofluid flow is observed under the effects of the magnetic field,activation energy and motile microorganisms over an inclined stretchable *** magnificent aspects of nanoliquid are demonstrated by enduring the Brownian motion and thermophoresis diffusion *** higher order partial differential equations are transformed into first-order ordinary differential equations with suitable similarity *** attained sets of governing equations are then cracked by bvp4 c procedure in MATLAB mathematical *** numerical and graphical outcomes of controlling parameters such as Prandtl number,mixed convection,activation energy,thermophoresis,Brownian parameter,Biot number,Lewis number,Peclet number and motile concentration parameter against the velocity,temperature,volumetric concentration and motile concentration of nanoparticles of the fluid are *** velocity is enhanced with the growth valuation in mixed convection and decay by rising variation of buoyancy ratio parameter,magnetic parameter and bio-convective Rayleigh *** evolution in motile microorganisms is due to the increasing values of microorganisms Biot *** presented data can be helpful in enhancement of manufacturing processes,biomolecules,extrusion systems applications and energy production improvement.

关键词： bio-convection magnetic-nanofluid Cattaneo–Christov theory motile microorganisms inclined stretching cylinder

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

N-Body Simulation Inspired by Metaheuristics Optimization

引用

Computer Systems Science & Engineering 2022年第6期41卷 1143-1155页

作者： muhammad Ali Ismail Maria waqas Farah Sadiq National Center in Big Data and Cloud Computing Department of Computer and Info Systems EngineeringNED University of Engineering and TechnologyKarachiPakistan

The N-body problem in classical physics, is the calculation of force ofgravitational attraction of heavenly bodies towards each other. Solving this problem for many heavenly bodies has always posed a challenge to physicists andmathematicians. Large number of bodies, huge masses, long distances and exponentially increasing number of equations of motion of the bodies have been themajor hurdles in solving this problem for large and complex galaxies. Adventof high performance computational machines have mitigated the problem to muchextent, but still for large number of bodies it consumes huge amount of resourcesand days for computation. Conventional algorithms have been able to reduce thecomputational complexity from O n2 ð Þ to O nlogn ð Þ by splitting the space into atree or mesh network, researchers are still looking for improvements. In thisresearch work we propose a novel solution to N-body problem inspired by metaheuristics algorithms. The proposed algorithm is simulated for various time periods of selected heavenly bodies and analyzed for speed and accuracy. Theresults are compared with that of conventional algorithms. The outcomes showabout 50% time saving with almost no loss in accuracy. The proposed approachbeing a metaheuristics optimization technique, attempts to find optimal solution tothe problem, searching the entire space in a unique and efficient manner in a verylimited amount of time.

关键词： N-body problem metaheuristics optimization particle swarm optimization heavenly bodies

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Significance of activation energy and Wu's slip features in Cross nanofluid with motile microorganisms

引用

Communications in Theoretical Physics 2020年第10期72卷 1-11页

作者： Sami Ullah Khan Hassan waqas Taseer muhammad muhammad Imran Malik Zaka Ullah Department of Mathematics COMSATS University IslamabadSahiwal 57000Pakistan Department of Mathematics Government College UniversityFaisalabad 38000Pakistan Department of Mathematics College of SciencesKing Khalid UniversityAbha 61413Saudi Arabia Department of Mathematics Faculty of ScienceKing Abdulaziz UniversityJeddah 21589Saudi Arabia

The current article investigates the impact of the bioconvection in an unsteady flow of magnetized Cross nanofluid with gyrotactic microorganisms and activation energy over a linearly stretched *** analysis has been performed by utilizing the realistic Wu's slip boundary and zero mass flux *** effects of nonlinear thermal radiation and the activation energy are also *** governing flow equations are deduced to a dimensionless form by considering suitable transformations which are numerically targeted via a shooting *** physical visualization of each physical parameter governing the flow problem has been displayed graphically for distribution of velocity,temperature,concentration and motile *** numerical treatment for the variation of skin friction coefficient,local Nusselt number,local Sherwood number and motile density number is performed in tabular forms.

关键词： Cross nanofluid nonlinear thermal radiation gyrotactic motile microorganism Wu's slip shooting technique

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Cu-Promoted Cobalt Oxide Film Catalyst for Efficient Gas Emissions Abatement

引用

Journal of Thermal Science 2019年第2期28卷 225-231页

作者： EL KASMI Achraf waqas muhammad MOUNTAPMBEME KOUTOU Patrick TIAN Zhenyu Institute of Engineering Thermophysics Chinese Academy of Sciences University of Chinese Academy of Sciences National Advanced School Engineering of Maroua University of Maroua

Thin film catalysts have been recently reported as promising catalysts owing to their good catalytic activity and reduced material amount, leading to low-cost efficient catalysts for gaseous emissions control. Here, we report the slight loading of Cu in cobalt spinel using a one-step pulsed-spray evaporation chemical vapor deposition(PSE-CVD) synthesis technique for efficient short-chain volatile organic compounds(VOCs) emissions treatment. Crystalline structure and morphology analyses revealed nano-crystallite sizes and open-like morphology. The catalytic performance was evaluated through the complete oxidation of C_3H_6, as a short-chain representative model of VOCs, at a high gas hourly space velocity(GHSV). Very good activity was obtained towards the complete abatement of C_3H_6 at low temperature and no carbon monoxide(CO) was formed during the oxidation process. Slightly-promoted Co_3O_4 catalyst with Cu introduction resulted in high catalytic activity comparing to the performance of the catalysts in the literature, due to the high dispersion of Cu and high active surface oxygen amount. Moreover, to evaluate the capability of the used catalysts under near realistic reaction conditions, CO_2 effect on the catalytic activity was performed and the catalyst exhibited very good results. Thus, the adopted slightly-doping strategy to tailor a high active catalyst at low temperature could establish a very promising route to strongly enhance the activity of such other catalysts towards gas emissions abatement at low temperature.

关键词： low Cu-doping PSE-CVD technique thin film catalysts complete catalytic oxidation VOCs

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Multi-objective design optimization of composite submerged cylindrical pressure hull for minimum buoyancy and maximum buckling load capacity

引用

Defence Technology（防务技术） 2021年第4期17卷 1190-1206页

作者： muhammad Imran Dong-yan Shi Li-li Tong Ahsan Elahi Hafiz muhammad waqas Muqeem Uddin College of Mechanical and Electrical Engineering Harbin Engineering University Harbin 150001China College of Aerospace and Civil Engineering Harbin Engineering University Harbin 150001China Pakhtunkhwa Energy Development Organization(PEDO) Khyber PakhtunkhwaPakistan

This paper presents the design optimization of composite submersible cylindrical pressure hull subjected to 3 MPa hydrostatic *** design optimization study is conducted for cross-ply layups[0_(s)/90_(t)/0_(u)],[0_(s)/90_(t)/0_(u)]s,[0_(s)/90_(t)]s and[90_(s)/0_(t)]s considering three uni-directional composites,***/Epoxy,Glass/Epoxy,and Boron/*** optimization study is performed by coupling a Multi-Objective Genetic Algorithm(MOGA)and Analytical *** the buoyancy factor and maximizing the buckling load factor are considered as the objectives of the optimization *** objectives of the optimization are achieved under constraints on the Tsai-Wu,Tsai-Hill and Maximum Stress composite failure criteria and on buckling load *** verify the optimization approach,optimization of one particular layup configuration is also conducted in ANSYS with the same objectives and constraints.

关键词： Multi-objective genetic algorithm Optimization Composite submersible pressure hull Thin shell Material failure Shell buckling

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Structure inversion asymmetry enhanced electronic structure and electrical transport in 2D A3SnO(A=Ca,Sr,and Ba)antiperovskite monolayers

引用

Nano Research 2023年第1期16卷 1779-1791页

作者： Syed muhammad Alay-e-Abbas Ghulam Abbas waqas Zulfiqar muhammad Sajjad Nirpendra Singh J.Andreas Larsson Applied Physics Division of Materials ScienceDepartment of Engineering Sciences and MathematicsLuleåUniversity of Technology97187 LuleåSweden Computational Materials Modeling Laboratory Department of PhysicsGovernment College UniversityFaisalabad 38040Pakistan Department of Energy Conversion and Storage Technical University of Denmark2800 Kgs.LyngbyDenmark Department of Physics Khalifa University of Science and TechnologyAbu Dhabi-127788United Arab Emirates Center for Catalysis and Separation(CeCaS) Khalifa University of Science and TechnologyAbu Dhabi-127788United Arab Emirates

Anti-perovskites A3SnO(A=Ca,Sr,and Ba)are an important class of materials due to the emergence of Dirac cones and tiny mass gaps in their band structures originating from an intricate interplay of crystal symmetry,spin–orbit coupling,and band *** provides an exciting playground for modulating their electronic properties in the two-dimensional(2D)***,we employ first-principles density functional theory(DFT)calculations by combining dispersion-corrected SCAN+rVV10 and mBJ functionals for a comprehensive side-by-side comparison of the structural,thermodynamic,dynamical,mechanical,electronic,and thermoelectric properties of bulk and monolayer(one unit cell thick)A3SnO *** results show that 2D monolayers derived from bulk A3SnO anti-perovskites are structurally and energetically ***,Rashba-type splitting in the electronic structure of Ca3SnO and Sr3SnO monolayers is observed owing to strong spin–orbit coupling and inversion *** the other hand,monolayer Ba3SnO exhibits Dirac cone at the high-symmetryΓpoint due to the domination of band *** on the predicted electronic transport properties,it is shown that inversion asymmetry plays an essential character such that the monolayers Ca3SnO and Sr3SnO outperform thermoelectric performance of their bulk counterparts.

关键词： electrical transport anti-perovskites low-dimensional materials electronic structure mechanical properties

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

DDoS Detection in SDN using Machine Learning Techniques

引用

Computers, Materials & Continua 2022年第4期71卷 771-789页

作者： muhammad waqas Nadeem Hock Guan Goh Vasaki Ponnusamy Yichiet Aun Faculty of Information and Communication Technology(FICT) Universiti Tunku Abdul Rahman(UTAR)Jalan UniversitiBandar Barat31900 KamparPerakMalaysia

Software-defined network(SDN)becomes a new revolutionary paradigm in networks because it provides more control and network operation over a network *** SDN controller is considered as the operating system of the SDN based network infrastructure,and it is responsible for executing the different network applications and maintaining the network services and *** all its tremendous capabilities,the SDN face many security issues due to the complexity of the SDN *** denial of services(DDoS)is a common attack on SDN due to its centralized architecture,especially at the control layer of the SDN that has a network-wide *** learning is now widely used for fast detection of these *** this paper,some important feature selection methods for machine learning on DDoS detection are *** selection of optimal features reflects the classification accuracy of the machine learning techniques and the performance of the SDN controller.A comparative analysis of feature selection and machine learning classifiers is also derived to detect SDN *** experimental results show that the Random forest(RF)classifier trains the more accurate model with 99.97%accuracy using features subset by the Recursive feature elimination(RFE)method.

关键词： Machine learning software-defined network distributed denial of services feature selection protection artificial neural network decision trees naïve bayes security

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Intrusion Detection Based on Bidirectional Long Short-Term Memory with Attention Mechanism

引用

Computers, Materials & Continua 2023年第1期74卷 801-815页

作者： Yongjie Yang Shanshan Tu Raja Hashim Ali Hisham Alasmary muhammad waqas muhammad Nouman Amjad Engineering Research Center of Intelligent Perception and Autonomous Control Faculty of Information TechnologyBeijing University of TechnologyBeijing100124China Faculty of Computer Science and Engineering GIK Institute of Engineering Sciences and TechnologyTopi23460Pakistan Department of Computer Science College of Computer ScienceKing Khalid UniversityAbhaSaudi Arabia Information Security and Cybersecurity Unit King Khalid UniversityAbhaSaudi Arabia Computer Engineering Department College of Information TechnologyUniversity of Bahrain32038Bahrain School of Engineering Edith Cowan UniversityJoondalup PerthWA6027Australia School of Engineering University of Management and TechnologyLahorePakistan

With the recent developments in the Internet of Things(IoT),the amount of data collected has expanded tremendously,resulting in a higher demand for data storage,computational capacity,and real-time processing *** computing has traditionally played an important role in establishing ***,fog computing has recently emerged as a new field complementing cloud computing due to its enhanced mobility,location awareness,heterogeneity,scalability,low latency,and geographic ***,IoT networks are vulnerable to unwanted assaults because of their open and shared *** a result,various fog computing-based security models that protect IoT networks have been developed.A distributed architecture based on an intrusion detection system(IDS)ensures that a dynamic,scalable IoT environment with the ability to disperse centralized tasks to local fog nodes and which successfully detects advanced malicious threats is *** this study,we examined the time-related aspects of network traffic *** presented an intrusion detection model based on a twolayered bidirectional long short-term memory(Bi-LSTM)with an attention mechanism for traffic data classification verified on the UNSW-NB15 benchmark *** showed that the suggested model outperformed numerous leading-edge Network IDS that used machine learning models in terms of accuracy,precision,recall and F1 score.

关键词： Fog computing intrusion detection bi-LSTM attention mechanism

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：