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Crustal structure beneath Tien Shan orogenic belt and its adjacent regions from multi-scale seismic data

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Science China Earth Sciences 2017年第10期60卷 1769-1782页

作者： n.Ghani khan BAI Ling ZHAO JunMeng LI GuoHui M.Moklesur RAHMAn CHEnG Cheng YAnG JianYa Key Laboratory of Continental Collision and Plateau Uplift Institute of Tibetan Plateau ResearchChinese Academy of Sciences Department of Earth Sciences COMSATS Institute of Information Technology (CIIT)

As one of the world's most active intracontinental mountain belts, Tien Shan has posed questions for researchers regarding the formation of different tectonic units and active shallow seismicity. Here, we used a huge data set comprising of 7094 earthquakes from local, regional and teleseismic seismic stations. We used waveform modeling and multi-scale double-difference earthquake relocation technique to better constrain the source parameters of the earthquakes. The new set of events provided us with better initial earthquake locations for further tomographic investigation. We found that reverse-faulting earthquakes dominate the whole study area while the fault plane solutions for earthquakes beneath the northwestern Tarim Basin and the Main Pamir Thrust are diverse. There is a low-velocity anomaly beneath Bashkaingdy at depth of 80 km, and high-velocity anomalies beneath central Tien Shan at shallower depths. These observations are the keys to understand the mechanism of Tien Shan's formation because of Tarim Basin northward and Kazakh Shield's southward subduction in the south and north respectively. Velocities beneath western Tien Shan are relatively high. We thus infer that the Western Tien Shan is relatively less deformed than the eastern Tien Shan primarily due to a relatively brittle mantle.

关键词： Tien Shan Earthquake relocation Velocity anomalies Differential subduction

Modeling the collapse of the Plasco *** I:Reconstruction of fire

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Building Simulation 2022年第4期15卷 583-596页

作者： Aatif Ali khan Ramakanth Veera Venkata Domada Xinyan Huang Mustesin Ali khan Asif Usmani Department of Building Services Engineering The Hong Kong Polytechnic UniversityKowloonHong KongChina Research Institute for Sustainable Urban Development The Hong Kong Polytechnic UniversityKowloonHong KongChina

In recent years,fires in tall buildings have become more frequent,which costs billions of dollars each year and the loss of many human *** facade fire in the Grenfell tower made the structure uninhabitable,and the collapse of the three World Trade Center(WTC)towers is the total structural failure caused by *** such events,no well-defined methodology exists to reconstruct both fire and structural behaviors and carrys out the forensic investigation of a building *** Part I paper collects the evidence of the Plasco Building fire and generates a coherent timeline to reconstruct the fire *** vertical and horizontal fire spread of the building is reconstructed using computational fluid dynamics(CFD)fire modeling and calibrated against the evidence *** spatio-temporal temperature history from the fire modeling provides realistic fire scenarios to simulate the structural *** fire simulation results are used as boundary conditions to be transferred to a finite element analysis tool for a detailed structural analysis to determine the likely collapse mechanism of the Plasco Building in Part *** methodology presented in this paper to reconstruct the fire can also guide the structural fire safety engineers to improve the building fire-safety and life-safety strategies.

关键词： building fire safety high-rise buildings fire investigation fire modeling structure failure

Investigation on the key aspects of l-arginine para nitrobenzoate monohydrate single crystal:A non-linear optical material

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Chinese Journal of Chemical Engineering 2019年第3期27卷 701-708页

作者： Sonia n.Vijayan Mahak Vij Kanika Thukral naghma khan D.Haranath Rajnikant M.S.Jayalakshmy Academy of Scientific and Innovative Research CSIR-National Physical Laboratory CSIR-national Physical Laboratory Department of Physics University of Jammu International and Inter University Centre for nanoscience and nanotechnology Mahatma Gandhi University

In the contemporary days, non-linear optical materials(nLO) are getting higher attention as per the increasing demand in optical communication and data storage technology. Consequently, they explore various physical properties of the nLO material for their industrial applications. In current report, l-arginine p-nitrobenzoate monohydrate(LAnB) single crystals were obtained by adopting slow cooling technique. The structural confirmation of grown single crystal was carried out using single crystal X-Ray diffractometer. Presence of strain within single crystal was deduced using Hall–Williamson relation. Various defects associated within single crystal were assessed using high resolution XRD. Additionally, its crystalline quality was again confirmed by time resolved photoluminescence spectroscopy(TRPL). Using transmission spectra, the cut off wavelength and band gap of the host material was determined to be nearly 420 nm and 2.9 e V respectively. The dielectric property has been recorded by varying the frequency ranging from 50 Hz to 100 k Hz. The curve suggests that dielectric loss value is less at high frequency ensures the suitability of crystal in photonics and nLO based *** laser damage threshold values were also measured for single and multiple shots. Thermal parameters of the titled compound were calculated using PPE. In photoconductivity measurement, negative photoconductivity has been observed in titled compound. Microhardness studies were also performed on single crystal to explore its mechanical properties.

关键词： Photoluminescence Thermal conductivity Specific heat Thermal effusivity Damage threshold

On Semilattice Decomposition of an Abel–Grassmann’s Groupoid

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Acta Mathematica Sinica,English Series 2012年第7期28卷 1461-1468页

作者： Madad khan Saima AnIS Department of Mathematics COMSATS Institute of Information Technology

In this paper, we have decomposed an AG-groupoid. Let S be an AG-groupoid with left identity and a relation γ be defined on S as： aγb if and only if there exist positive integers m and n such that b^m∈E （Sa）S and a^n ∈ （Sb）S for all a and b in S. We have proved that S/γ is a maximal separative Semilattice homomorphic image of S. Every AG-groupoid S is uniquely expressible as a semilattice Y of archimedean AG-groupoids Sa （a∈ Y）. The semilattice Y is isomorphic to S/γ and the Sγ （a ∈ Y） are the equivalence classes of S mod V.

关键词： AG-groupoid invertive law medial law congruence

A Secure Communication Protocol for Unmanned Aerial Vehicles

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Computers, Materials & Continua 2022年第1期70卷 601-618页

作者： navid Ali khan n.Z.Jhanjhi Sarfraz nawaz Brohi Abdulwahab Ali Almazroi Abdulaleem Ali Almazroi School of Computer Science and Engineering(SCE) Taylor’s University Lake-side CampusSubang Jaya47500Malaysia School of Information and Technology Monash UniversityMalaysia University of Jeddah College of Computing and Information Technology at KhulaisDepartment of Information TechnologyJeddahSaudi Arabia Department of Computer Science Rafha Community CollegeNorthern Border UniversityArar91431Saudi Arabia

Mavlink is a lightweight and most widely used open-source communication protocol used for Unmanned Aerial *** UAVs and autopilot systems support it,and it provides bi-directional communication between the UAV and Ground Control *** communications contain critical information about the UAV status and basic control commands sent from GCS to UAV and UAV to *** order to increase the transfer speed and efficiency,the Mavlink does not encrypt the *** a result,the protocol is vulnerable to various security attacks such as Eavesdropping,GPS Spoofing,and *** this study,we tackle the problem and secure the Mavlink communication *** leveraging the Mavlink packet’s vulnerabilities,this research work introduces an experiment in which,first,the Mavlink packets are compromised in terms of security requirements based on our threat *** results show that the protocol is insecure and the attacks carried out are *** overcomeMavlink security,an additional security layer is added to encrypt and secure the *** encryption technique is proposed that makes the communication between the UAV and GCS *** results show that the Mavlink packets are encrypted using our technique without affecting the performance and *** results are validated in terms of transfer speed,performance,and efficiency compared to the literature solutions such as MAVSec and benchmarked with the original Mavlink *** achieved results have significant improvement over the literature and Mavlink in terms of security.

关键词： Unmanned aerial vehicles mavlink protocol drones security UAVs communication

A note on Bell-Based Bernoulli and Euler Polynomials of Complex Variable

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Computer Modeling in Engineering & Sciences 2023年第4期135卷 187-209页

作者： n.Alam W.A.khan S.Obeidat G.Muhiuddin n.S.Diab H.n.Zaidi A.Altaleb L.Bachioua Department of Basic Sciences Deanship of Preparatory YearUniversity of Ha’ilHa’il2440Saudi Arabia Department of Mathematics and natural Sciences Prince Mohammad Bin Fahd UniversityAl Khobar31952Saudi Arabia Department of Mathematics Faculty of ScienceUniversity of TabukTabuk71491Saudi Arabia

In this article,we construct the generating functions for new families of special polynomials including two parametric kinds of Bell-based Bernoulli and Euler *** fundamental properties of these functions are *** using these generating functions and some identities,relations among trigonometric functions and two parametric kinds of Bell-based Bernoulli and Euler polynomials,Stirling numbers are *** formulae for these polynomials are *** a partial derivative operator to these generating functions,some derivative formulae and finite combinatorial sums involving the aforementioned polynomials and numbers are also *** addition,some remarks and observations on these polynomials are given.

关键词： Bernoulli polynomials euler polynomials bell polynomials stirling numbers

Microstructure and properties of nano-Tin modified Ti(C,n)-based cermets fabricated by powder injection molding and die pressing

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International Journal of Minerals,Metallurgy and Materials 2013年第11期20卷 1115-1121页

作者： Shan-jie Yi Hai-qing Yin Ke Chen Dil-Faraz khan Qing-jun Zheng Xuan-hui Qu School of Materials Science and Engineering University of Science and Technology Beijing Department of Physics University of Science and Technology Bannu Kennametal Inc. 1600 Technology Way Latrobe

Powder injection molding （PIM） and die pressing were employed to fabricate nano-Tin modified Ti（C,n）- based cermets. The shrinkage behavior, microstructure, porosity, and mechanical properties of the samples with and without nano-Tin addition fabricated by PIM and die pressing were analyzed. It is demonstrated that for either PIM or die pressing, the porosities are obviously reduced, the mechanical properties are significantly improved after adding nano-Tin, and the hard particles are refined; the rim phase thickness obviously becomes thinner, and the number of dimples in fracture also increases. Compared the samples fabricated by die pressing, it is difficult for PIM to obtain dense Ti（C,n）-based cermets. Due to the too much existence of pores and isolated carbon, the mechanical properties of the sintered samples by PIM are inferior to those of the sintered ones by die pressing.

关键词： cermets powder injection molding die pressing titanium nitride nanoparticles mechanical properties

Efficient Authentication System Using Wavelet Embeddings of Otoacoustic Emission Signals

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Computer Systems Science & Engineering 2023年第5期45卷 1851-1867页

作者： V.Harshini T.Dhanwin A.Shahina n.Safiyyah A.nayeemulla khan Department of Information Technology Sri Sivasubramaniya Nadar College of EngineeringChennai603110India School of Computer Science and Engineering Vellore Institute of TechnologyChennai600127India

Biometrics,which has become integrated with our daily lives,could fall prey to falsification attacks,leading to security *** our paper,we use Transient Evoked Otoacoustic Emissions(TEOAE)that are generated by the human cochlea in response to an external sound stimulus,as a biometric *** are robust to falsification attacks,as the uniqueness of an individual’s inner ear cannot be *** this study,we use both the raw 1D TEOAE signals,as well as the 2D time-frequency representation of the signal using Continuous Wavelet Transform(CWT).We use 1D and 2D Convolutional neural networks(Cnn)for the former and latter,respectively,to derive the feature *** corresponding lower-dimensional feature maps are obtained using principal component analysis,which is then used as features to build classifiers using machine learning techniques for the task of person identification.T-SnE plots of these feature maps show that they discriminate well among the *** the various architectures explored,we achieve a best-performing accuracy of 98.95%and 100%using the feature maps of the 1D-Cnn and 2D-Cnn,respectively,with the latter performance being an improvement over all the earlier *** performance makes the TEOAE based person identification systems deployable in real-world situations,along with the added advantage of robustness to falsification attacks.

关键词： Person identification system cochlea:transient evoked otoacoustic emission wavelet transform convolutional neural network

Sunflower-Like SrCo_(2)S_(4)@f-MWCnTs Hybrid Wrapped by Engineering n-Reduced Graphene Oxide for High Performance Dye-Sensitized Solar Cells

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Journal of Renewable Materials 2020年第4期8卷 431-446页

作者： Weiming Zhang Muhammad Wasim khan Xueqin Zuo Qun Yang Huaibao Tang Shaowei Jin Guang Li School of Physics and Materials Science Anhui UniversityHefei230601China Anhui Key Laboratory of Information Materials and Devices Hefei230601China Institute of Physical Science and Information Technology Anhui UniversityHefei230601China

A novel sunflower-like nanocomposite of SrCo_(2)S_(4)nanoflakes and functionalized multiwall carbon nanotubes(f-MWCnTs)entanglement enveloped in nitrogen-reduced graphene oxide(n-RGO)is prepared by a cheap *** unique entanglement structure of the material exhibits higher specific surface area,better electrical conductivity and other *** helps to reduce the transfer resistance in the photoelectric process of the battery and improve the electrochemical activity,thus increasing the photoelectric conversion efficiency of the *** new ternary cobalt-based sulfide material can replace platinum as the counter electrode(CE)material loaded on dye-sensitized solar cells(DSSCs).DSSCs with SrCo_(2)S_(4)@f-MWCnTs@n-RGO(SCS@f-M@n-R)as CE material show excellent photoelectric conversion efficiency(PCE,8.06%),even surpassing than that of Pt CE material(7.51%).The low cost,excellent electrocatalytic performance and simple preparation method of SCS@f-M@n-R nanomaterial provide feasibility for replacing platinum material as the CE material of DSSCs,which is of great significance and persuasion.

关键词： Dye-sensitized solar cells sunflower-like multiwall carbon nanotubes SrCo_(2)S_(4) counter electrode