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The impact of Persian oak (Quercus brantii Lindl.) on soil characteristics in a declining forest

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Journal of Forestry Research 2020年第6期31卷 2359-2366页

作者： Reza Soleimani ahmad Hosseini Crop and Horticultural Science Research Department Ilam Agricultural and Natural Resources Research and Education CenterAREEOIlamIran Forests and Rangelands Research Department Ilam Agricultural and Natural Resources Research and Education CenterAREEOIlamIran

Root activity has an important impact on soil development but we have little knowledge of the interaction of the root zone and soil genetic *** aim of this investigation was to study the interactions between soil chemical characteristics and root zone processes in a declining Persian oak forest(Quercus brantii Lindl.).A randomized complete block design was used to investigate the long-term eff ect of Persian oak on soil horizons,and the chemical and biological properties in two soil zones(under and outside the canopy).Results indicate that the rhizosphere zone had signifi cantly higher total organic carbon(TOC)than outside the canopy soil in the upper soil *** subsurface horizons,water-extractable organic carbon values were signifi cantly higher in rhizosphere than in non-rhizospheric *** biomass carbon(MBC)values in the rhizospheric zone decreased from the fi rst to the second *** MBC/TOC ratio indicated signifi-cant diff erences between the rhizosphere and soils outside of the canopy,with the exception of the subsurface *** the subsurface horizon of the rhizosphere,there was greater respiration of organic carbon(ΣCO 2/TOC)than in outside of canopy *** addition,root processes infl uenced pH,nitrogen fractions,and availability of phosphorus,potassium,iron,zinc and *** erences in soil characteristics between rhizospheric and non-rhizospheric zones were signifi cant in surface horizons due to higher root density than in deeper soil *** fi ndings indicate that Persian oak(Quercus brantii Lindl.)roots infl uenced the main soil chemical properties,even in calcareous soils.

关键词： Declining forest Persian oak Rhizosphere Soil horizons

Analysis of the seventh-order Caputo fractional KdV equation:applications to the Sawada-Kotera-Ito and Lax equations

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Communications in Theoretical Physics 2023年第8期75卷 14-24页

作者： Shabir ahmad Sayed Saifullah Department of Mathematics University of MalakandChakdaraDir LowerKhyber PakhtunkhwaPakistan

In this study,we investigate the seventh-order nonlinear Caputo time-fractional KdV *** suggested model's solutions,which have a series form,are obtained using the hybrid ZZ-transform under the aforementioned fractional *** proposed approach combines the homotopy perturbation method(HPM)and the *** consider two specific examples with suitable initial conditions and find the series solution to test their *** demonstrate the utility of the presented technique,we explore its applications to the fractional Sawada–Kotera–Ito problem and the Lax *** observe the impact of a few fractional orders on the wave solution evolution for the problems under *** provide the efficiency and reliability of the ZZHPM by calculating the absolute error between the series solution and the exact solution of both the Sawada–Kotera–Ito and Lax *** convergence and uniqueness of the solution are portrayed via fixed-point theory.

关键词： seventh-order KdV equation soliton homotopy perturbation method

Color-flavor dependence of the Nambu-Jona-Lasinio model and QCD phase diagram

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Chinese Physics C 2022年第8期46卷 128-140页

作者： Aftab ahmad Ali Murad Institute of Physics Gomal University29220D.I.KhanKhyber PakhtunkhawPakistan

We study the dynamical chiral symmetry breaking/restoration for various numbers of light quarks flavors N_(f) and colors N_(c) using the Nambu-Jona-Lasinio(NJL) model of quarks in the Schwinger-Dyson equation framework,dressed with a color-flavor dependence of effective *** fixed N_(f)=2 and varying N_(c),we observe that the dynamical chiral symmetry is broken when N_(c) exceeds its critical value N_(c)^(c)≈*** a fixed N_(c)=3 and varying N_(f),we observe that the dynamical chiral symmetry is restored when Nf reaches its critical value N_r^(c)≈*** interplay is observed between N_(c) and N_(f),i.e.,larger values of N_(c) tend to strengthen the dynamical generated quark mass and quark-antiquark condensate,while higher values of N_(f) suppress both *** further sketch the quantum chromodynamics(QCD) phase diagram at a finite temperature T and quark chemical potential μ for various N_(c) and N_(f).At finite T and μ,we observe that the critical number of colors N_(c)^(c) is enhanced,whereas the critical number of flavors N_(f)^(c) is suppressed as T and μ ***,the critical temperature T_(c),μ_(c),and co-ordinates of the critical endpoint(T_(c)^(E),μ_(c)^(E)) in the QCD phase diagram are enhanced as N_(c) increases and suppressed when N_(f) *** findings agree with the lattice QCD and Schwinger-Dyson equations predictions.

关键词： chiral symmetry breaking Schwinger-Dyson equation finite temperature and density QCD phase diagram

Photometry and spectroscopy ofⅡPeg,IM Peg and UX Ari

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Research in Astronomy and Astrophysics 2018年第9期18卷 79-88页

作者： Ajaz ahmad Dar Padmakar Singh Parihar Manzoor ahmad Malik Department of Physics University of KashmirHazratbal 190006 Srinagar-J&KIndia Department of Physics Islamia College of Science and CommerceHawalSrinagar-19002J&KIndia Indian Institute of Astrophysics Koramagala-560034BangaloreIndia

Ⅴ band photometry of three RS CVn stars,Ⅱ Peg, IM Peg and UX Ari, is carried out to study the physical properties of these variables. We verified the significant and regular optical photometric variability to be present in all three stars. The strong photometric variability and emission of Hα and Ca Ⅱ H ＆ K using high resolution optical spectroscopy with the Hanle Echelle Spectrograph （HESP）, which operates in conjunction with the Himalayan Chandra Telescope, verify the strong chromospheric activity which is present in RS CVn stars. The photometric studies of Ⅱ Peg, UX Ari and IM Peg were subjected to light curve analysis for spot parameters using a two-starspot model.

关键词： RS CVn star spots chromospherically active

Phase Transitions in the Early Universe with Negatively Induced Supergravity Cosmological Constant

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Chinese Physics Letters 2006年第5期23卷 1124-1127页

作者： EL-NABULSI ahmad Rami Plasma Application Laboratory Department of Nuclear and Energy Engineering and Faculty of Mechanical Energy and Production Engineering Cheju National University Ara-dong 1 Jeju 690-756 South Korea

We consider that the observable cosmological constant is the sum of the vacuum （Avac） and the induced term （Aind - 3m^2/4） with m being the ultra-llght masses （≈ Hubble parameter） implemented in the theory from supergravities arguments and non-minimal coupling. In the absence of a scalar buildup of matter fields, we study its effects on spontaneous symmetry breaking with a Higgs potential and show how the presence of the ultra-light masses yields some important consequences for the early universe and new constraints on the Higgs and electroweak gauge bosons masses.

关键词： SPONTANEOUS SYMMETRY-BREAKING MASSLESS PARTICLES CURVED SPACETIME GAUGE-THEORIES CURVATURE MODELS FIELD

A system dynamics model for billion trees tsunami afforestation project of Khyber Pakhtunkhwa in Pakistan:Model application to afforestation activities

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Journal of Mountain Science 2019年第11期16卷 2640-2653页

作者： Naila NAZIR Aqsa FAROOQ Sajjad ahmad JAN Aftab ahmad Department of Economics University of PeshawarKhyber Pakhtunkhwa 25000Pakistan Department of Economics Edwardes CollegePeshawar Saddar 25000Pakistan Global Change Impact Study Center Ministry of Climate Change10-Mauve AreaG-8/1IslamabadPakistan

As part of the global effort to plant billion trees,an afforestation project is launched in Pakistan in Khyber Pakhtunkhwa(KP)province to conserve existing forests and to increase area under forest *** present study is designed to build a Systems'model by incorporating major activities of the Billion Tree Tsunami Afforestation Project(BTTAP)with special focus on afforestation activities to estimate the growth in forest area of *** of complete dataset was a *** fix the model,the raw data taken from the project office has been *** Commission Form 1-Phase I&II helped us with additional *** relied on the data available for one and half period of the project as rest of the data is subject to the completion of the *** results show that the project target to enhance area under forest differs from the target to afforest area under the *** system dynamics'model projection shows that the forest area of KP would be 23.59 million hectares at the end of the BTTA project,thus having an increase of 3.29%instead of 2%that has been initially ***,the results show that the progress to meet the target in some afforestation classes is slow as compared to other *** forestry,plantation on communal lands and owners'plantation need special focus of the *** would affect 0.02 million hectares area of the *** model under study may be used as a reference model that can be replicated to other areas where billion tree campaigns are going on.

关键词： Billion trees project Afforestation System dynamic model Forest area Deforestation Pakistan

Synchronous self-learning Pareto strategy An ensemble framework for vector and multi-criterion optimization

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International Journal of Intelligent Computing and Cybernetics 2018年第2期11卷 197-233页

作者： ahmad Mozaffari Systems Design Engineering Department University of WaterlooWaterlooCanada

Purpose–In recent decades,development of effective methods for optimizing a set of conflicted objective functions has been absorbing an increasing interest from *** refers to the essence of real-life engineering systems and complex natural mechanisms which are generally multi-modal,non-convex and *** now,several deterministic and stochastic methods have been proposed to cope with such complex *** soft computational methods such as evolutionary games(cooperative and non-cooperative),Pareto-based techniques,fuzzy evolutionary methods,cooperative bio-inspired algorithms and neuro-evolutionary systems have effectively come to the aid of researchers to build up efficient paradigms with application to vector *** paper aims to discuss this ***/methodology/approach–A novel hybrid algorithm called synchronous self-learning Pareto strategy(SSLPS)is presented for the sake of vector *** method is the ensemble of evolutionary algorithms(EA),swarm intelligence(SI),adaptive version of self-organizing map(CSOM)and a data shuffling *** are powerful numerical optimization algorithms capable of finding a global extreme point over a wide exploration *** techniques(the swarm of bees in our case)can improve both intensification and robustness of *** network is an unsupervised learning methodology which learns the characteristics of non-dominated solutions and,thus,enhances the quality of the Pareto ***–To prove the effectiveness of the proposed method,the authors engage a set of well-known benchmark functions and some well-known rival optimization ***,SSLPS is employed for optimal design of shape memory alloy actuator as a nonlinear multi-modal real-world engineering *** experiments show the acceptable potential of SSLPS for handling both numerical and engineering multi-objective ***/value–To the author’s best knowledge,the propos

关键词： Self-organizing map Swarm and evolutionary computation Unsupervised machine assisted optimization Vector optimization

Evaluation of stiffness in a cellulose fiber reinforced epoxy laminates for structural applications:Experimental and finite element analysis

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Defence Technology（防务技术） 2018年第4期14卷 278-286页

作者： Furkan ahmad Pramendra Kumar Bajpai MPAE Division Netaji Subhas Institute of TechnologyUniversity of Delhi

Natural fiber composites have been proved to have the ability to replace the synthetic fiber composites in many structural applications. Unprecedented growth in the field of computational techniques has opened the doors of analysis and simulation of composite materials under various *** and simulation using various available softwares saves a lot of time and resources. In the present work, an attempt has been made to analyze the tensile behavior of jute fiber reinforced epoxy based polymer composite materials using the student version of commercially available finite element code Siemens PLM NX 10.0. In most of the structural applications, materials are required to have enough stiffness to resist the shape deformation under normal loading conditions. Therefore, emphasis is given to the load-deformation behavior of the developed composites. A 3-dimensional model of the test specimen was developed using ply-stacking method and the strain-stress values were verified by the available literature. The model showed a good agreement between the experimental and software results. Effect of ply angle, fiber percentage, fiber type, number of layers and weft fiber angle on the stiffness of laminate have been studied.

关键词： Finite element analysis Jute fiber Polymer composite Ply-stacking Weft fiber angle Laminates analysis

CHEMICAL SYNTHESIS,SPECTRAL CHARACTERIZATION AND STABILITY OF SOME ELECTRICALLY CONDUCTING POLYMERS

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Chinese Journal of Polymer Science 2010年第2期28卷 191-197页

作者： Pradeep Kumar Upadhyay Afaq ahmad Department of Chemistry Aligarh Muslim University

The synthesis, characterization, thermal degradation and stability of polyaniline （PANI）, poly（m-nitroaniline）, poly（m-chloroaniline） and poly（o-methylaniline） were reported. Different properties were measured and compared with PANI to find out the effect of electron donating groups （-CH3） and electron withdrawing groups （-Cl, -NO2）. It was found that the presence of any type of substitution in the benzene ring of aniline increased the solubility but reduced the yield, thermal stability and electrical conductivity. Two probe methods were used to measure the electrical conductivity of these polymers. The structural properties of these polymers were characterized by using FTIR and UV-Vis spectroscopic methods. Thermal degradation and stability of these polymers were explained by using thermogravimetric analysis （TGA） and conductivity measurements.

关键词： Polyaniline Electrical conductivity Yield Thermal degradation Stability.