检索结果-南通市图书馆

Journal of Ocean Engineering and Science 2024年第2期9卷 112-125页

作者： m.Higazy Norah Almalki shabbir muhammad A.Al-Ghamdi Department of mathematics and Statistics College of ScienceTaif UniversityP.O.Box 11099Taif 21944Saudi Arabia Department of Physics and Engineering mathematics Faculty of Electronic EngineeringMenoufia UniversityMenouf 32952Egypt Research Center for Advanced materials Science(RCAmS) King Khalid UniversityP.O.Box 9004Abha 61413Saudi Arabia Department of Chemistry College of ScienceKing Khalid UniversityP.O.Box 9004Abha 61413Saudi Arabia Department of Physics Faculty of ScienceKing Abdulaziz UniversityP.O.Box 80203Jeddah 21589Saudi Arabia

A new fractional 6D chaotic model is constructed in this *** new fractional 6D chaotic model has six positive parameters plus the fractional order with eight nonlinear *** complicated chaotic dy-namics of the new fractional 6D model is presented and *** basic properties of this model are studied and its chaotic attractors,dissipative feature,symmetry,equilibrium points,Lyapunov Exponents are *** new dynamics of the 6D fractional model is numerically simulated using matlab *** addition,utilizing the graph theory tools certain structural characteristics are *** electrical circuit is built to implement the new 5.4 fractional order 6D ***,an active fractional order controller is proposed to control the new model at different fractional *** chaos of the new model is very useful and can be used to produce random keys for data encryption.

关键词： Chaotic systems Fractional calculus Lyapunov exponents Chaotic attractors Adjacency matrix Hermitian matrix Electronic circuit realization

multifunctional mXene/Carbon Nanotube Janus Film for Electromagnetic Shielding and Infrared Shielding/Detection in Harsh Environments

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

Nano-micro Letters 2024年第10期16卷 543-560页

作者： Tufail Hassan Aamir Iqbal Byungkwon Yoo Jun Young Jo Nilufer Cakmakci shabbir m.dad naqvi Hyerim Kim Sungmin Jung Noushad Hussain Ujala Zafar Soo Yeong Cho Seunghwan Jeong Jaewoo Kim Jung min Oh Sangwoon Park Youngjin Jeong Chong min Koo School of Advanced materials Science and Engineering Sungkyunkwan UniversitySeobu-ro 2066Jangan-guSuwon-siGyeonggi-do 16419Republic of Korea Department of materials Science and Engineering Soongsil UniversitySeoul 06978Republic of Korea Institute of Advanced Composite materials Korea Institute of Science and Technology92 Chudong-roBongdong-eupWanju-gunJeollabuk-do 55324Republic of Korea R&D Center INNOmXENE Co. Ltd.Daejeon 34365Republic of Korea School of Chemical Engineering Sungkyunkwan UniversitySeobu-ro 2066Jangan-guSuwon-siGyeonggi-do 16419Republic of Korea

multifunctional,flexible,and robust thin films capable of operating in demanding harsh temperature environments are crucial for various cutting-edge *** study presents a multifunctional Janus film integrating highly-crystalline Ti_(3)C_(2)T_(x) mXene and mechanically-robust carbon nanotube(CNT)film through strong hydrogen *** hybrid film not only exhibits high electrical conductivity(4250 S cm^(-1)),but also demonstrates robust mechanical strength and durability in both extremely low and high temperature environments,showing exceptional resistance to thermal *** hybrid Janus film of 15μm thickness reveals remarkable multifunctionality,including efficient electromagnetic shielding effectiveness of 72 dB in X band frequency range,excellent infrared(IR)shielding capability with an average emissivity of 0.09(a minimal value of 0.02),superior thermal camouflage performance over a wide temperature range(−1 to 300℃)achieving a notable reduction in the radiated temperature by 243℃ against a background temperature of 300℃,and outstanding IR detection capability characterized by a 44%increase in resistance when exposed to 250 W IR *** multifunctional mXene/CNT Janus film offers a feasible solution for electromagnetic shielding and IR shielding/detection under challenging conditions.

关键词： mXene/carbon nanotube Janus film Electromagnetic interference shielding Infrared shielding Thermal camouflage Infrared detection

Phytodiversity and medicinal plant distribution in pasturelands of North Western Himalaya in relation to environmental gradients

在线全文

学校读者我要写书评

暂无评论

Journal of mountain Science 2019年第4期16卷 884-897,955-963页

作者： Javaid m.dad Central Institute of Temperate Horticulture

This study aimed at elucidating phytodiversity of pasturelands of North-western Kashmir Himalayan biotic province in relation to various environmental gradients, with added focus on assessing distribution of important threatened medicinal plant taxa across surveyed pasturelands. A total of 16 sites that spanned across a broad altitudinal gradient(2502-4120 m) were selected. Phytosociological data like density, cover, frequency and abundance of vascular flora were collected and processed using gradient analysis. Soil moisture, nitrogen, organic carbon, acidity and electrical conductivity, altitude, degree of slope and human disturbance were recorded from each site. Analysis of species composition showed a total of 293 species of vascular plants, belonging to 192 genera and 64 families recorded from surveyed sites. Rank abundance exhibited that majority of species are locally rare and patchily distributed, with over 60% of species recording frequencies between 0%-20% and none showing frequencies more than 80%. Species richness showed significant variations and ranged from 20(Parihasmaidan) to 114(Nagbarren) for macro and 3.53±2.11(Thajwas) to 8.76± 1.01(marsar) for micro-scale of measurement. The ShannonWiener(H') and Simpson's diversity(Ds) indices also varied greatly and were recorded highest(H'= 2.76 & Ds= 0.36) for marsar and lowest(0.87 & 0.62) for Parihasmaidan. The diversity attributes suggested that pasturelands with lower species richness and diversity on macro-scale were not always species poor and less diverse on micro-measurement scale. The life form groupings highlighted the hemicryptophytic character of vegetation and species with highest importance value index were Sibbaldia cuneata(5.71), Rumex nepalensis(2.89), Juniperus wallichiana(2.88), Cynodon dactylon(2.83), Poa annua(2.49) and Sambucus wightiana(2.41). The results of canonical correspondence analysis showed that effect of altitude and anthropogenic disturbance was overriding and among various en

关键词： Anthropogenic disturbance Kashmir Himalaya medicinal plants mountain grasslands

On new classes of strongly Janowski type functions of complex order

在线全文

学校读者我要写书评

暂无评论

Applied mathematics(A Journal of Chinese Universities) 2023年第1期38卷 89-99页

作者： Khalil Ahmad Khudija Bibi m.Sajjad shabbir Department of mathematics Air UniversityPAF-ComplexSector E-9IslamabadPakistan Department of mathematics Faculty of Basic and AppliedInternational Islamic University IslamabadPakistan Department of mathematics University of Poonch RawalakotAzad Kashmir 12350Pakistan

We investigate some new subclasses of analytic functions of Janowski type of complex *** also study inclusion properties,distortion theorems,coefficient bounds and radius of convexity of the ***,analytic properties of these classes under certain integral operator are also *** findings are more comprehensive than the existing results in the literature.

关键词： subordination Janowski function starlike function convex function complex order

Changes in soil organic carbon,nitrogen and sulphur along a slope gradient in apple orchard soils of Kashmir Himalaya

在线全文

学校读者我要写书评

暂无评论

Journal of mountain Science 2021年第9期18卷 2377-2387页

作者： Javaid m.dad Lotfollah ABDOLLAHI Department of Botany University of KashmirHazratbalSrinagar(J&K)India Faculty of Agriculture Payame Noor UniversityTehranP.O.Box 19395-3697Iran

Accumulation and losses of soil organic carbon(SOC),total nitrogen(TN)and sulphur(S)influence food security and global ***,their spatial distribution and variability at regional scale,and their relation to topographical variables are of great *** this study,the variability of SOC,TN and S content was evaluated in apple orchard soils of Kashmir region,at three depths(D1:0-10,D2:10-20,and D3:20-30 cm)on slope gradient i.e.:flat,medium,and *** an increase in slope,a significant decrease of SOC and TN was observed,with concentration of SOC and TN recorded highest(14.3±2.06 g kg-1&0.97±0.35 g kg-1)in flat slope orchards and lowest(9.6±2.07 g kg-1&0.84±0.41 g kg-1)in high slope *** stock basis,the values recorded for flat,medium,and high slope orchards,for SOC and TN were 54.62±4.24 mg ha-1&0.38±0.06 mg ha-1,44.13±5.11 mg ha-1&0.32±0.09 mg ha-1,and 38.73±5.94 mg ha-1&0.28±0.10,*** differences for S concentration and stocks were modest,with flat(0.21±0.15 mg kg-1&0.09±0.0.003 mg ha-1)>high(0.16±0.07 mg kg-1&0.06±0.007 mg ha-1)>medium(0.12±0.04 mg kg-1&0.075±0.009 mg ha-1).Across slopes,SOC,TN and S decreased with increasing soil depth,suggesting clear downward ***,SOC and TN increased with the increase of altitude,precipitation and clay content while its relationship with soil acidity and soil bulk density was *** findings may provide scientific basis to structure agricultural development plans or prioritize regions for soil conservation efforts.

关键词： Apple orchards Slope Soil organic carbon Sulphur Total nitrogen Soil bulk density

Density functional theory study of structural,electronic,and thermal properties of Pt,Pd,Rh,Ir,Os and PtPdX(X=Ir,Os,and Rh)alloys

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2016年第3期25卷 298-306页

作者： shabbir Ahmed muhammad Zafar m Shakilt m A Choudhary Simulation Laboratory Department of Physicsthe Islamia University of BahawalpurBahawalpur 63100Pakistan o Department of Physics Hafiz Hayat CampusUniversity of GujratGujrat 50700Pakistan

The structural, electronic, mechanical, and thermal properties of Pt, Pd, Rh, Ir, Os metals and their alloys PtPdX （X = Ir, Os and Rh） are studied systematically using ab initio density functional theory. The groundstate properties such as lattice constant and bulk modulus are calculated to find the equilibrium atomic position for stable alloys. The electronic band structure and density of states are calculated to study the electronic behavior of metals on making their alloys. The electronic properties substantiate the metallic behavior for all studied materials. The firstprinciples density functional perturbation theory as implemented in quasi-harmonic approximation is used for the calculations of thermal properties. We have calculated the thermal properties such as the Debye temperature, vibrational energy, entropy and constant-volume specific heat. The calculated properties are compared with the previously reported experimental and theoretical data for metals and are found to be in good agreement. Calculated results for alloys could not be compared because there is no data available in the literature with such alloy composition.

关键词： electronic structural and thermal properties platinum group metals

First-principles calculations of structural, electronic, and thermodynamic properties of ZnO_(1-x)S_x alloys

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2014年第10期23卷 394-400页

作者： muhammad Zafar shabbir Ahmed m.Shakil m.A.Choudhary Simulation Laboratory Department of Physics The Islamia University of Bahawalpur

In this study the pseudo-potential method is used to investigate the structural, electronic, and thermodynamic proper- ties of ZnOl_xSx semiconductor materials. The results show that the electronic properties are found to be improved when calculated by using LDA ~ U functional as compared with local density approximation （LDA）. At various concentrations the ground-state properties are determined for bulk materials ZnO, ZnS, and their tertiary alloys in cubic zinc-blende phase. From the results, a minor difference is observed between the lattice parameters from Vegard＇s law and other calculated results, which may be due to the large mismatch between lattice parameters of binary compounds ZnO and ZnS. A small deviation in the bulk modulus from linear concentration dependence is also observed for each of these alloys. The ther- modynamic properties, including the phonon contribution to Helmholtz free energy △F, phonon contribution to internal energy △E, and specific iheat at constant-volume Cv, are calculated within quasi-harmonic approximation based on the calculated phonon dispersion relations.

关键词： first principles calculations density functional theory (DFT) semiconductor materials structural,electronic, and thermal properties

Proper Teleparallel Homothetic Vector Fields in General Cylindrically Symmetric Space-Times in Teleparallel Theory of Gravitation Using Diagonal Tetrads

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2017年第11期67卷 611-616页

作者： Ghulam shabbir masoom Ali Shahani m.Amer Qureshi F.m.mahomed Faculty of Engineering Sciences GIK Institute of Engineering Sciences and Technology School of mathematics University of the Witwatersrand

In this paper we consider the most general form of non-static cylindrically symmetric space-times in order to study proper teleparallel homothetic vector fields using the direct integration technique and diagonal tetrads. This study also covers static cylindrically symmetric, Bianchi type I, non-static and static plane symmetric space-times as well. Here, we will only discuss the cases which do not fall in the category of static cylindrically symmetric, Bianchi type Ⅰ, non-static and static plane symmetric space-times. From the above study we show that very special classes of the above space-times yield 6, 7 and 8 teleparallel homothetic vector fields with non-zero torsion.

关键词： proper teleparallel homothetic vector field Weitzenbck geometry Torsion

Theoretical calculations of structural, electronic, and elastic properties of CdSe_(1-x)Te_x:A first principles study

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2016年第7期25卷 324-330页

作者： m Shakil muhammad Zafar shabbir Ahmed muhammad Raza-ur-rehman Hashmi m A Choudhary T Iqbal Department of Physics Hafiz Hayat Campus University of Gujrat Simulation Laboratory Department of Physics the Islamia University of Bahawalpur

The plane wave pseudo-potential method was used to investigate the structural, electronic, and elastic properties of Cd Se_（1-x）Te_x in the zinc blende phase. It is observed that the electronic properties are improved considerably by using LDA ＋ U as compared to the LDA approach. The calculated lattice constants and bulk moduli are also comparable to the experimental results. The cohesive energies for pure Cd Se and Cd Te binary and their mixed alloys are calculated. The second-order elastic constants are also calculated by the Lagrangian theory of elasticity. The elastic properties show that the studied material has a ductile nature.

关键词： first principles calculations density functional theory II–VI semiconductors structural electronic and elastic properties

Theoretical investigation of sulfur defects on structural, electronic,and elastic properties of ZnSe semiconductor

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2015年第7期24卷 365-370页

作者： muhammad Zafar shabbir Ahmed m.Shakil m.A.Choudhary K.mahmood Simulation Laboratory Department of PhysicsThe Islamia University of Bahawalpur 63100Pakistan Department of Physics GC UniversityFaisalabad 68000Pakistan

The structural, electronic, and elastic properties of ZnSe1-xSx for the zinc blende structures have been studied by using the density functional theory. The calculations were performed using the plane wave pseudopotential method, as implemented in Quantum ESPRESSO. The exchange-correlation potential is treated with the local density approximation pz-LDA for these properties. moreover, LDA＋U approximation is employed to treat the ＂d＂ orbital electrons properly. A comparative study of the band gap calculated within both LDA and LDA＋U schemes is presented. The analysis of results show considerable improvement in the calculation of band gap. The inclusion of compositional disorder increases the values of all elastic constants. In this study, it is found that elastic constants C11, C12, and C44 are mainly influenced by the compositional disorder. The obtained results are in good agreement with literature.

关键词： first principles calculations density functional theory II–VI semiconductors electronic and elastic properties