检索结果-南通市图书馆

Effect of Minor Alloying on Crystallization Behavior and Thermal Properties of Zr_(64.5)Ni_(15.5)Al_(11.5)Cu_(8.5) Bulk Amorphous Alloy

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2011年第6期27卷 534-538页

作者： muhammad Iqbal javed Iqbal Akhter Haifeng Zhang Zhuangqi Hu MicrostructuralStudies Group Physics Division Pakistan Institute of Nuclear Science and Technology (PINSTECH) P.O. Nilore Islamabad Pakistan Shenyang Nationel Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China

Minor alloying plays an important role in the synthesis and improvement of thermal stability of bulk metallic glasses（BMGs）.The present study was conducted to investigate the effect of minor additions of Y,Ti and Nb on the crystallization behavior and the thermal properties of Zr64.5Ni15.5Al11.5Cu8.5 *** parameters and the activation energies for crystallization were calculated for four（Zr0.645Ni0.155Al0.115-Cu0.085）100-xMx（M=Y,Ti and Nb,while x=0,2 at.） *** present alloys have wide supercooled liquid region of ≥87 *** activation energy was found to be greater than 300 kJ/mol for the base *** crystalline phases were identified in the samples annealed at 823 K for 20 *** glass transition temperature（Trg） and other thermal parameters such as γ,δ and β were improved by Y and Ti *** addition resists crystallization below annealing temperature 713 K,however,its effect on thermal properties is not very promising.

关键词： Activation energy Thermal properties Glass-forming ability Thermal stability Precipitation Microstructure

Efficient UAV Communications: Recent Trends and Challenges

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2021年第4期67卷 463-476页

作者： Abdulfattah Noorwali muhammad Awais javed Mohammad Zubair Khan Department of Electrical Engineering Umm Al-Qura UniversityMakkah21961Saudi Arabia Department of Electrical and Computer Engineering COMSATS University Islamabad45550Pakistan Department of Computer Science College of Computer Science and EngineeringTaibah University MadinahSaudi Arabia

Unmanned Ariel Vehicles(UAVs)are flying objects whose trajectory can be remotely *** have lot of potential applications in the areas of wireless communications,internet of things,security,traffic management,monitoring,and smart *** enabling reliable communication between UAVs and ground nodes,emergency notifications can be efficiently and quickly disseminated to a wider *** can gather data from remote areas,industrial units,and emergency scenarios without human *** can support ubiquitous connectivity,green communications,and intelligent wireless resource *** efficiently use UAVs for all these applications,important challenges need to be *** this paper,we first present a detailed classification of UAVs based on factors such as their size,communication range,weight,and flight *** also explain the hardware system configuration and uses of these *** present a brief overview of recent work done related to three major challenges in *** challenges include trajectory control,energy efficiency and resource *** also present three open challenges and future opportunities for efficient UAV *** include use of learning algorithms for resource allocation and energy efficiency in UAVs,intelligent surfaces-based communications for enhanced reliability in UAVs,and security algorithms to combat malicious attacks against UAVs.

关键词： UAVs resource allocation energy efficiency trajectory control

Phonon Thermal Transport at Interfaces of a Graphene/Vertically Aligned Carbon Nanotubes/Hexagonal Boron Nitride Sandwiched Heterostructure

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 2024年第1期41卷 57-62页

作者：李檬璘 muhammad asif Shakoori 王瑞鹏李海鹏 School of Materials Science and Physics China University of Mining and TechnologyXuzhou 221116China

Molecular dynamics simulation is used to calculate the interfacial thermal resistance of a graphene/carbon nanotubes/hexagonal boron nitride(Gr/CNTs/hBN)sandwiched heterostructure,in which vertically aligned carbon nanotube(VACNT)arrays are covalently bonded to graphene and hexagonal boron nitride *** find that the interfacial thermal resistance(ITR)of the Gr/VACNT/hBN sandwiched heterostructure is one to two orders of magnitude smaller than the ITR of a Gr/hBN van der Waals heterostructure with the same plane *** is observed that covalent bonding effectively enhances the phonon coupling between Gr and hBN layers,resulting in an increase in the overlap factor of phonon density of states between Gr and hBN,thus reducing the ITR of Gr and *** addition,the chirality,size(diameter and length),and packing density of sandwich-layer VACNTs have an important influence on the ITR of the *** the same CNT diameter and length,the ITR of the sandwiched heterostructure with armchair-shaped VACNTs is higher than that of the sandwiched heterostructure with zigzag-shaped VACNTs due to the different chemical bonding of chiral CNTs with Gr and *** the armchair-shaped CNT diameter increases or the length decreases,the ITR of the sandwiched heterostructure tends to ***,the increase in the VACNT packing density also leads to a continuous decrease in the ITR of the sandwiched heterostructure,attributed to the extremely high intrinsic thermal conductivity of CNTs and the increase of out-of-plane heat transfer *** work may be helpful for understanding the mechanism for ITR in multilayer vertical heterostructures,and provides theoretical guidance for a new strategy to regulate the interlayer thermal resistance of heterostructures by optimizing the design of sandwich layer thermal interface materials.

关键词： sandwich shaped packing

From Molecular Pathology of COVID-19 to Nigella Sativum as a Treatment Option:Scientific Based Evidence of Its Myth or Reality

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Integrative Medicine 2022年第1期28卷 88-95页

作者： muhammad Atif Farrah Naz Junaid Akhtar muhammad Imran Sidrah Saleem javed Akram muhammad Imran muhammad Ikram Ullah Department of Clinical Laboratory Sciences College of Applied Medical SciencesJouf UniversitySakaka(75471)Saudi Arabia Department of Microbiology Government College UniversityFaisalabad(38000)Pakistan Department of Microbiology University of Health SciencesLahore(54600)Pakistan Department of Allied Health Sciences Sargodha Medical CollegeUniversity of SargodhaSargodha(40100)Pakistan University of Health Sciences Lahore(54600)Pakistan University Institute of Diet and Nutritional Sciences Faculty of Allied Health SciencesThe University of LahoreLahore(54590)Pakistan

COVID-19 virus is a causative agent of viral pandemic in human beings which specifically targets respiratory system of humans and causes viral *** unusual viral pneumonia is rapidly spreading to all parts of the world,currently affecting about 105 million people with 2.3 million *** review described history,genomic characteristics,replication,and pathogenesis of COVID-19 with special emphasis on Nigella sativum(***)as a treatment *** seeds are historically and religiously used over the centuries,both for prevention and treatment of different *** review summarizes the potential role of *** seeds against COVID-19 infection at levels of in silico,cell lines and animal models.

关键词： coronavirus nCoV-19 COVID-19 Nigella sativum review

End-To-End Encryption Enabled Lightweight Mutual Authentication Scheme for Resource Constrained IoT Network

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2025年第2期82卷 3223-3249页

作者： Shafi Ullah Haidawati muhammad Nasir Kushsairy Kadir Akbar Khan Ahsanullah Memon Shanila Azhar Ilyas Khan muhammad Ashraf Department of Computer Engineering Balochistan University of Information TechnologyEngineering and Management SciencesQuetta87300Pakistan Computer Engineering Section Malaysian Institute of Technology Universiti Kuala LumpurKuala Lumpur50250Malaysia Electrical Engineering Section Universiti Kuala LumpurBritish Malaysian InstituteSalengor53100Malaysia Electrical Engineering Department Mehran UniversityKhairpur-Mirs76062Pakistan Department of Mathematics College of Science Al-ZulfiMajmaah UniversityAl-Majmaah11952Saudi Arabia

Machine-to-machine (M2M) communication networks consist of resource-constrained autonomous devices, also known as autonomous Internet of things (IoTs) or machine-type communication devices (MTCDs) which act as a backbone for Industrial IoT, smart cities, and other autonomous systems. Due to the limited computing and memory capacity, these devices cannot maintain strong security if conventional security methods are applied such as heavy encryption. This article proposed a novel lightweight mutual authentication scheme including elliptic curve cryptography (ECC) driven end-to-end encryption through curve25519 such as (i): efficient end-to-end encrypted communication with pre-calculation strategy using curve25519;and (ii): elliptic curve Diffie-Hellman (ECDH) based mutual authentication technique through a novel lightweight hash function. The proposed scheme attempts to efficiently counter all known perception layer security threats. Moreover, the pre-calculated key generation strategy resulted in cost-effective encryption with 192-bit curve security. It showed comparative efficiency in key strength, and curve strength compared with similar authentication schemes in terms of computational and memory cost, communication performance and encryption robustness.

关键词： Mutual authentication lightweight end-to-end encryption elliptic curve cryptography industrial internet of things curve25519 machine-to-machine communication

Bio-inspired computational heuristics to study models of HIV infection of CD4＋ T-cell

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Biomathematics 2018年第2期11卷 83-114页

作者： muhammad asif Zahoor Raja Kiran Asma muhammad Saeed Aslam Department of Electrical Engineering COMSATS Institute of Information Technology Attoek Campus Attock Pakistan Department of Computer Sciences COMSATS Institute of Information Technology Attock Campus Attock Pakistan Pakistan Institute of Engineering and Applied Sciences Nilore Islamabad Pakistan

In this work, biologically-inspired computing framework is developed for HIV infection of CD4＋ T-cell model using feed-forward artificial neural networks （ANNs）, genetic algorithms （GAs）, sequential quadratic programming （SQP） and hybrid approach based on GA-SQP. The mathematical model for HIV infection of CD4＋ T-cells is represented with the help of initial value problems （IVPs） based on the system of ordinary differential equations （ODEs）. The ANN model for the system is constructed by exploiting its strength of universal approximation. An objective function is developed for the system through unsupervised error using ANNs in the mean square sense. Training with weights of ANNs is carried out with GAs for effective global search supported with SQP for efficient local search. The proposed scheme is evaluated on a number of scenarios for the HIV infection model by taking the different levels for infected cells, natural substitution rates of uninfected cells, and virus particles. Comparisons of the approximate solutions are made with results of Adams numerical solver to establish the correctness of the proposed scheme. Accuracy and convergence of the approach are validated through the results of statistical analysis based on the sufficient large number of independent runs.

关键词： HIV infection model bioinformatics artificial neural networks genetic algo-rithms.

Entropies of the Y-Junction Type Nanostructures

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2023年第6期135卷 2665-2679页

作者： Ricai Luo Aisha javed muhammad Azeem muhammad Kamran Jamil Hassan Raza muhammad Yasir Ilyas School of Mathematics and Physics Hechi UniversityYizhou456300China Abdus Salam School of Mathematical Sciences Government College UniversityLahore54000Pakistan Department of Mathematics Riphah Institute of Computing and Applied SciencesRiphah International UniversityLahore54000Pakistan School of Mathematical Sciences College of Science and TechnologyWenzhou-Kean UniversityWenzhou325060China Department of Physics COMSATS University IslamabadLahore54000Pakistan

Recent research on nanostructures has demonstrated their importance and application in a variety of *** are used directly or indirectly in drug delivery systems,medicine and pharmaceuticals,biological sensors,photodetectors,transistors,optical and electronic devices,and so *** discovery of carbon nanotubes with Y-shaped junctions is motivated by the development of future advanced electronic *** of their interactionwithY-junctions,electronic switches,amplifiers,and three-terminal transistors are of particular *** is a concept that determines the uncertainty of a system or *** concepts are also used in biology,chemistry,and applied *** on the requirements,entropy in the form of a graph can be classified into several *** 1955,graph-based entropy was *** of the types of entropy is edgeweighted *** examined the abstract form of Y-shaped junctions in this *** edge-weight-based entropy formulas for the generic view of Y-shaped junctions were created,and some edge-weighted and topological index-based concepts for Y-shaped junctions were discussed in the present paper.

关键词： Y-shaped junctions three-terminal junctions nanostuctures entropy carbon nanotube

Chemical synthesis of zinc oxide nanorods for enhanced hydrogen gas sensing

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2014年第1期23卷 509-512页

作者： Musarrat Jabeen muhammad Azhar Iqbal R Vasant Kumar Mansoor Ahmed muhammad Tayyeb javed Department of Physics University of the Punjab Lahore Pakistan Department of Material Science and Metallurgy University of Cambridge England Department of Chemical Engineering Pakistan Institute of Engineering and Applied Sciences Nilore Islamabad Pakistan

Zinc oxide （ZnO） nanorods are prepared using equimolar solution of zinc nitrate （（Zn（NO3）2） and hexamethylenete- tramine （C6HleN4） by the hydrothermal technique at 80 ~C for 12 h. Epitaxial growth is explored by X-ray diffraction （XRD） patterns, revealing that the ZnO nanorods have a hexagonal （wurtzite） structure. Absorption spectra of ZnO are measured by UV-visible spectrometer. The surface morphology is investigated by field emission scanning electron mi- croscopy （FESEM）. The synthesized ZnO nanorods are used for detecting the 150 ~C hydrogen gas with a concentration over 1000 ppm. The obtained results show a reversible response. The influence of operating temperature on hydrogen gas detecting characteristic of ZnO nanorods is also investigated.

关键词： zinc oxide hydrothermal synthesis nanorods hydrogen gas sensor

Progress in electrocatalytic nitrate reduction for green energy:Catalyst engineering,mechanisms,and techno-economic feasibility

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第8期95卷 380-406,I0009页

作者： Hafiz muhammad Adeel Sharif Hafiz muhammad Farooq Khan Sadeeq Ullah Yuwei Wang muhammad Ahmad Bo Yang Changping Li muhammad Bilal asif Research Center for Eco-Environmental Engineering Dongguan University of TechnologyDongguan 523808GuangdongChina College of Chemistry and Engineering Shenzhen UniversityShenzhen 518060GuangdongChina FMH College of Medicine and Dentistry LahorePakistan School of Environment and Civil Engineering Research Center for Eco-Environment EngineeringDongguan University of TechnologyDongguan 523106GuangdongChina Advanced Membranes and Porous Materials Center(AMPMC) Physical Sciences and Engineering(PSE)King Abdullah University of Science and Technology(KAUST)Thuwal 23955Saudi Arabia

Ammonia(NH_(3))is an irreplaceable chemical that has been widely demanded to keep the sustainable development of modern ***,its industrial production consumes a huge amount of energy and releases extraordinary greenhouse gases(GHGs),leading to various environmental *** the green production of ammonia is a great challenge,which has been extensively pursued in the last *** this review,the most promising strategy,electrochemical nitrate reduction reaction(e-NO_(3)RR),is comprehensively investigated to give a complete understanding of its development and mechanism and provide guidance for future ***,owing to the complex reactions and limited selectivity,a comprehensive understanding of the mechanisms is crucial to further development and ***,NO_(3)^(-)RR is a promising strategy for simultaneous water treatment and NH_(3)production.A detailed overview of the recent progress in NO_(3)^(-)RR for NH_(3)production with nontransition and transition metal based electrocatalysts is *** addition,critical advanced techniques,future challenges,and prospects are discussed to guide future research on transition metal-based catalysts for commercial NH_(3)synthesis by NO_(3)^(-)reduction.

关键词： Nitrate reduction Electrolysis Pollution to solution Transition metal catalysts Ammonia synthesis Green energy