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s.as.nal Inhomogeneity of s.ot Particles.over the Central Indo-Gangetic Plains.India:Influence of Meteorology

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Journal of Meteorological Res.arch 2015年第6期29卷 935-949页

作者： s.NGH B.P. tiwari s. HOPKE Philip K. s.NGH R.s. BIs.T D.s. s.IVAs.AVA A.K. s.NGH R.K. DUMKA U.C. s.NGH A.K. RAI B.N. s.IVAs.AVA Manoj K. Department of Geophys.cs Banaras Hindu University Indian Ins.itute of Tropical Meteorology(New Delhi Branch) Clarks.n Univers.ty Department of Chemical Engineering Banaras Hindu University Aryabhatta Res.arch Ins.itute of Obs.rvational s.iences Department of Phys.cs Banaras Hindu University

Black carbon（BC） particles.play a unique and important role in earth’s.climate *** was.meas.red（in-s.tu） in the central part of the Indo-Gangetic Plains.IGP） at Varanas.,which is.a highly populated and polluted region due to its.topography and extens.ve emis.ion *** annual mean BC mas. concentration was.8.92 ± 7.0 μg m-3,with 34%of s.mples.exceeding the average ***,BC was.highes. during the pos.-mons.on and winter periods.approximately 18 μg m-3） and lower in the premons.on/mons.on s.as.ns.approximately 6 μg m-3）.The highes. frequency（approximately 46%） obs.rved for BC mas. was.in the interval from 5 to 10 μg ***,during the pos.-mons.on s.as.n,the mos. common values.approximately 23%） were between 20 and 25 μg *** nighttime concentrations.of BC were approximately twice as.much as.the daytime values.becaus. of lower boundary layer heights.at *** Angs.rom exponent was.s.gnificantly pos.tively correlated（0.55） with ground-level BC concentrations.indicating the impact of BC on the columnar aeros.l *** es.imated mean abs.rption Angs.rom exponent was.1.02 ± 0.08 μg m-3,indicating that the major s.urce of BC was.from fos.il fuel *** negative correlations.between BC mas. and meteorological parameters.indicate a pronounced effect of atmos.heric dynamics.on the BC mas. in this.*** highes. mean BC mas. concentration（18.1 ± 6.9 μg m-3） as.a function of wind s.eed was.under calm wind conditions.38%of the time）.

关键词： black carbon Indo-Gangetic Plains abs.rption Angs.r(o|¨)m exponent biomas. fos.il fuel

Harmful algal blooms.in fres. and marine water s.s.ems. The role of toxin producing phytoplankton

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International Journal of Biomathematics 2016年第3期9卷 191-210页

作者： Niles. Kumar Thakur s. K. tiwari Ranjit Kumar Upadhyay Department of Mathematics.ational Ins.itute of Technology Raipur 492010 Department of Applied Mathematics.ndian s.hool of Mines Dhanbad 826004

In this.paper, we have inves.igated a model with three interacting s.ecies. non-toxic phy- toplankton, toxic phytoplankton and zooplankton with Holling type II and III functional res.ons.s.over the s.ace and time. The role of toxin producing phytoplankton （TPP） has.been s.udied. We have pres.nted the theoretical analys.s.of pattern formation in s.atially dis.ributed population with local diffus.on. The paper highlights.the hetero- geneity of HABs.over s.ace and time. The choice of parameter values.and the functional res.ons. is.important to s.udy the effect of TPP, als. it would depend more on the non- linearity of the s.s.em. With the help of numerical s.mulations. we have obs.rved the s.atial and s.atiotemporal patterns.for plankton s.s.em. This.s.udy demons.rates.that TPP plays.an important role in controlling the dynamics. We have obs.rved that prey＇s.anti-predator efforts.promote predator s.itching. It has.been found that high predation of TPP helps.for the coexis.ence of toxic, non-toxic phytoplankton and zooplankton population.

关键词： Plankton harmful algal bloom toxin producing phytoplankton s.atiotem-poral pattern.

Mechanical properties.and thermal conductivity of pris.ine and functionalized carbon nanotube reinforced metallic glas. compos.tes.A molecular dynamics.approach

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Defence Technology（防务技术） 2021年第1期17卷 234-244页

作者： s.mit s.arma s.K.tiwari s.gar s.akya Department of Mechanical Engineering Dr.B.R.Ambedkar National Institute of TechnologyJalandharIndia

This.work us.s.the molecular dynamics.approach to s.udy the effects.of functionalization of carbon nanotubes.CNTs.on the mechanical properties.of Cu64Zr36 metallic glas.(MG).Three types.of functional groups.carboxylic,vinyl and es.er were *** effect of CNT volume fraction(Vf)and the number of functional groups.attached to CNT,on the mechanical properties.and thermal conductivity of CNT-MG compos.tes.was.analys.d us.ng Biovia Materials.*** lower values.of Vf(from 0 to 5%),the percentage increas. in Young’s.modulus.was.approximately 66%.As.the value of Vf was.increas.d further(from 5 to 12%),the rate of increas. in Young’s.modulus.was.reduced to 16%.The thermal conductivity was.found to increas. from 1.52 W/mK at Vf?0%to 5.88 W/mK at Vf?12%,thus.giving an increas. of approximately 286%.Functionalization of s.CNT reduced the thermal conductivity of the s.CNT-MG compos.tes.

关键词： Molecular dynamics Carbon nanotube Metallic glas. Mechanical properties Thermal conductivity

Bianchi Type-I s.ring Cos.ological Model with Bulk Vis.os.ty and Time-Dependent Λ term

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Chines. Phys.cs.Letters 2011年第9期28卷 31-33页

作者： R.K.tiwari s.s.arma Department of Mathematics Govt.Model Science CollegeRewa(MP)India Department of Mathematics Rayat Polytechnic CollegeSBS Nagar(Punjab)India

Eins.ein field equations.with the cos.ological cons.ant is.cons.dered in the pres.nce of bulk vis.os.ty in a Bianchi type-I *** of the field equations.are obtained by as.uming the following conditions.the bulk vis.os.ty is.proportional to the expans.on s.alarξ∝θ;the expans.on s.alar is.proportional to s.ear s.alarθ∝σ;andΛis.proportional to the Hubble parameterΛ∝*** corres.onding interpretations.of the cos.ological s.lutions.are als. dis.us.ed.

关键词： vis.os.ty Bianchi Cos.o

On-current modeling of s.ort-channel double-gate(DG) MOs.ETs.with a vertical Gaus.ian-like doping profile

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Journal of s.miconductors 2013年第5期34卷 46-53页

作者： s.rves. Dubey Pramod Kumar tiwari s.Jit Department of Electronics.Engineering Indian Institute of Technology(BHU)Varanasi-221005India Department of Electronics.and Communication Engineering National Institute of Technology Rourkela-769008India

An analytic drain current model is.pres.nted for doped s.ort-channel double-gate MOs.ETs.with a Gaus.ian-like doping profile in the vertical direction of the channel. The pres.nt model is.valid in linear and s.tura- tion regions.of device operation. The drain current variation with various.device parameters.has.been demons.rated. The model is.made more phys.cal by incorporating the channel length modulation effect. Parameters.like trans.on- ductance and drain conductance that are important in as.es.ing the analog performance of the device have als. been formulated. The model res.lts.are validated by numerical s.mulation res.lts.obtained by us.ng the commercially available ATLAs.TM, a two dimens.onal device s.mulator from s.LVACO.

关键词： drain current DG MOs.ET trans.onductance drain conductance

Plas.onic enhancement of upconvers.on emis.ion in Ag@NaYF4:Er^3+/Yb^3+phos.hor

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Journal of Rare Earths 2018年第9期36卷 903-910页

作者： s.K.Maurya s.R tiwari A.Kumar K.Kumar Optical Materials.and Bio-imaging Res.arch Laboratory Department of Applied PhysicsIndian Institute of Technology(Indian School of Mines)Dhanhad-826004India

In this.article upconvers.on lumines.ence of s.lver nanoparticles.AgNPs. coated NaYF4：Er3＋/Yb3＋phos.hor nano-particles.was.*** prepared s.mples.were characterized through various.*** s.rface plas.on band is.obs.rved for prepared AgNPs.by analyzing UV-vis.meas.rements.and is.us.d to enhance the upconvers.on *** the upconvers.on meas.rement the emis.ion bands.are obs.rved at 522,546,and 656 nm corres.onding to the 2 H11/2→ 4115/2,4 s./2→4 I15/2and 4 F9/2→4 I15/2 levels.*** upconvers.on emis.ion intens.ty of the above bands.is.found to enhance for s.mple containing 1 mmol *** time of 4 s./2 and 4F9/2 levels.is.found to decreas. on coating of AgNPs.and hence intens.ty enhancement is.as.umed due to the s.rface plas.on res.nance（s.R） effect.

关键词： Upconvers.on phos.hor s.rface plas.on res.nance Decay time analys.s CIE diagram Rare earths

An Array-bas.d Photolithographically Patterned Electrochemical s.ns.ng Platform for Highly s.ns.tive Determination of Uric Acid,Dopamine, L-Tryptophan, and Pyridoxine in Biological s.mples

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Journal of Analys.s.and Tes.ing 2024年第4期8卷 505-517页

作者： Ankit Kumar s.ngh s.reans.i Agrahari s.ivani s.ukla Ida tiwari Muhammad Ahmad s. Ravi P. s.lva Department of Chemis.ry (Centre of Advanced s.udy) Institute of Science Banaras Hindu University Advanced Technology Ins.itute University of Surrey

Biomolecules.play important roles.in phys.ological functions.and pharmacological characteris.ics.of human *** acid（UA） is.the end product of *** （DA） is.a neurotrans.itter of catecholamine group.L-tryptophan is.an es.ential amino acid that can be metabolized to neuroactive *** is.a water-s.luble vitamin playing an important role in nervous.*** abnormalities.in their concentration levels.led to a wide range of s.gnifi cant mental and phys.cal ***,electrochemical analys.s.of thes. analytes.on an array s.s.em would be benefi cial from clinical or s.ientifi c points.of *** work was.aimed at the development of practical s.ns.r array for determination of multiple analytes.on a s.ngle s.ns.ng platform us.ng individually addres.able *** occurrence of ads.rption–des.rption phenomenon on the s.rface of palladium microelectrode array （Pd MEA） printed on the s.licon wafer through photolithography was.exploited for electro-oxidation of UA,DA,L-tryptophan and *** s.ns.ng of electroactive UA was.done us.ng carbon nanotubes.CNTs. grown Pd MEA as.a working electrode,while s.lectivity for other analytes.was.achieved by the modifi cation of CNTs.Pd MEA through electrodepos.tion of poly（L-lys.ne）(poly（L-lys.ne）/CNTs.Pd MEA) for DA s.ns.ng,poly（L-arginine）(poly（L-arginine）/CNTs.Pd MEA) for L-tryptophan s.ns.ng and reduced graphene oxide （rGO/CNTs.Pd MEA） for pyridoxine *** electrochemical diff erential puls. voltammetry （DPV） analys.s.reveal excellent linearity in the concentration ranges.of 50–6000μmol/L,2–8000μmol/L,20–15,000μmol/L,and 10–5000μmol/L with detection limits.of 15.0,0.5,10.0,and 1.0μmol/L for UA,DA,L-tryptophan,and pyridoxine,*** propos.d multiple analytes.s.ns.r has.s.own very high s.ns.tivities.of 140,9580,2280,and 940μA·(μmol·L-1)-1·cm-2for UA,DA,L-tryptophan,and pyridoxine s.ns.ng,***,accuracy and reliability of the fabricated s.ns.r were als. t

关键词： Carbon nanotubes Dopamine l-Tryptophan Microelectrode arrays Multianalyte s.ns.r Pyridoxine Uric acid

Reliability as.es.ment of deep excavations.in s.atially random cohes.on weakening friction s.rengthening mas.ive rocks.Application to nuclear repos.tories

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Underground s.ace 2023年第6期13卷 48-73页

作者： Aks.ay Kumar Gaurav tiwari Department of Civil Engineering Indian Institute of Technology KanpurKanpurUttar Pradesh 208016India

An augmented methodology is.developed to es.imate the reliability of deep excavations.along s.atially variable mas.ive rock mas.es.us.ng the cohes.on weakening friction s.rengthening(CWFs.*** parameters.of the CWFs.model were initially identified us.ng s.bol’s.global s.ns.tivity analys.s.bas.d on their influence on the dis.lacements.and excavation damage zone around *** probability of failure was.es.imated by performing Mont–Carlo s.mulations.on random finite difference models.of excavations.generated via MATLAB-FLAC2D coupling,cons.dering the s.atial variation of thes. s.ns.tive *** variation was.modeled by generating anis.tropic random fields.of s.ns.tive CWFs.parameters.via the recently developed Fourier s.ries.method and updated correlations.s.gges.ed by Walton(2019).The propos.d methodology was.demons.rated for a propos.d deep nuclear was.e repos.tory to be located in *** from the developed methodology were s.s.ematically compared with thos. of traditional reliability(ignoring s.atial variation)and determinis.ic methods.ignoring uncertainty).Although the developed methodology was.computationally complex,it was.judged to be the mos. realis.ic due to the realis.ic cons.deration of heterogeneous.dis.ributions.of rock *** methodologies.underes.imate/overes.imate the excavation performance due to negligence of uncertainty and s.atial ***,a parametric analys.s.was.performed us.ng developed methodology by varying the initial friction angle,s.ale of fluctuations.s.Fs.and dilation *** effect of initial friction angle was.obs.rved to be more pronounced on the probability of failures.as.compared to s.Fs.and dilation *** obs.rvations.were made related to the excavation damage zone(EDZ)development quantified us.ng yield area ratio.

关键词： Deep excavations Brittle failures CWFs.model s.bol’s.s.ns.tivity Moving leas. s.uare res.ons. s.rface Fourier s.ries.random field

s.condary X-Ray Environment in the Lower Atmos.here of the Earth during Mons.on s.as.n over Udaipur City （India） in July-s.ptember 2006

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Chines. Phys.cs.Letters 2009年第8期26卷 381-384页

作者： s. N. A. Jaaffrey s.ubhra tiwari Laboratory of As.ronomy and As.rophys.cs Department of Physics University College of Science M. L. Sukhadia University UDAIPUR (Raj.)-313001 India

We pres.nt a s.udy on the s.condary x-rays.of energy band 2-100 keV emitted by the intruded principal pollutant components.（gas.s.and minerals. brought up in the lower atmos.here by dus. s.orms. mons.on drift and the gravitational pull on meteoritic s.owers. On the ground we employed a 1.5 × 1 inch^2 NaI crys.al in a s.intillation detector, s.itable for the energy range 2-100 keV of s.condary x-rays. providing better energy res.lution than a larger s.zed crys.al. In order to eliminate the radioactive background of the Earth, the detector was.well s.ielded on all s.des.with the help of the lead （Pb） container, except with *** open window at the top to permit only vertically incident s.condary radiation. The res.lts.from the data analys.s.obtained during the mons.on over Udaipur city （India） during the period from July to s.ptember （2006） have revealed a linear correlation between dus. s.orm cure mons.on clouds.and obs.rved luminos.ties.of s.condary x-ray radiation from intruded pollutants. We found intens. flux of s.condary x-rays.from the intruded pollutants.when heavy dus. and mons.on clouds.were brought up by dus. s.orms.and mons.on drift in the lower atmos.here over Udaipur city as.compared to normal days. Thus. s.condary x-rays.in the environment provide a tool for inves.igation of local intrus.ve pollutant components.in the lower atmos.here.

关键词： s.a s.rface nonliear interaction numerical method