检索结果-南通市图书馆

Efficient nonenzymatic hydrogen peroxide sensor in acidic media based on Prussian blue nanoparticles-modified poly(o-phenylenediamine)/glassy carbon electrode

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2016年第3期27卷 481-486页

作者： Reza Ojani Parisa Hamidi jahan-Bakhsh Raoof Electroanalytical Chemistry Research Laboratory Faculty of ChemistryUniversity of Mazandaran

The Prussian blue nanoparticles（PBNPs） were prepared by a self-assembly process, on a glassy carbon（GC） electrode modified with a poly（o-phenylenediamine）（Po PD） film. The stepwise fabrication process of PBNPs-modified Po PD/GCE was characterized by scanning electron microscopy（SEM） and electrochemical impedance spectroscopy. The prepared PBNPs showed an average size of 70 nm and a homogeneous distribution on the surface of modified electrodes. The PBNPs/Po PD/GCE showed adequate mechanical, electrochemical stability and good sensitivity in comparison with other PB based H2O2 sensors. The present modified electrode exhibited a linear response for H2O2 reduction over the concentration range of 1–58.22 mmol L ^-1with a detection limit of ca. 0.8 mmol L ^-1（S/N = 3）, and sensitivity of 3187.89 m A（mol L ^-1） ^-1cm ^-2using the amperometric method. This sensor was employed for the H2O2 determination in real sample and also exhibited good interference resistance and selectivity.

关键词： Self-assembly Prussian blue nanoparticles Hydrogen peroxide Sensor

Comprehensive isotopic characterization of the hydrological processes of the Indus river basin(IRB):A comparison between Upper Indus Basin(UIB)and Lower Indus Basin(LIB)

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2023年第3期20卷 705-723页

作者： Akhtar jahan Tanveer DAR Sudhir KUMAR Nachiketa RAI Department of Earth Sciences Indian Institute of TechnologyRoorkee 247667India National Institute of Hydrology Roorkee 247667India

The Indus river basin(IRB)is one of the most depleted water basins globally,having significant challenges for its water *** of stable isotope composition(δ^(18)O and δ^(2)H)across IRB is a critical aspect that can provide deeper insights for investigating complex hydrological *** work analyses the spatial pattern of the isotopic signature using a comprehensive compilation of available datasets of the Global Network of Isotopes in River(GNIR)and Global Network of Isotopes in Precipitation(GNIP),along with the previously published isotopic studies in the Indus ***,this work provides a detailed comparison of the isotopic signature of the Upper Indus Basin(UIB),and Lower Indus Basin(LIB).The IRBs waterline was found to beδ^(2)H=7.89×δ^(18)O+13.51,which shows a close similarity with the Global Meteoric Water Line(GMWL),indicating the meteoric origin of the water with insignificant secondary evaporation prevailing across the *** Main Indus Channel(MIC)river water line(δ^(2)H=8.88×δ^(18)O+26.05)indicates a major contribution from the meteoric origin(precipitation/rain)of water with minimal effect of evaporation *** water line for UIB samples,(δ^(2)H=7.88×δ^(18)O+11.94)was found to be moderately higher in slope than LIB samples(δ^(2)H=7.17×δ^(18)O+7.16).However,the slopes of both UIB and LIB river water lines closely approached the slope of GMWL and were consistent with the slope of IRB water line,which indicates similarity in contribution of water *** higher slope and intercept in UIB suggest that meteoric water sources contributed to streamflow *** snow/glacier with insignificant evapotranspiration,which is also validated by the scarce vegetation cover in the ***,the lower slope and intercept in LIB suggest stream water contribution from significantly evaporated groundwater and precipitation with a complete homogenization of discharge coming from the *** substantiate that distinct isotopi

关键词： Isotopes Spatial variability Indian summer monsoon Western Disturbance Indus river Water

Effect of seismic wave propagation in massed medium on rate-dependent anisotropic damage growth in concrete gravity dams

在线全文

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2021年第2期15卷 346-363页

作者： Alireza DANESHYAR Hamid MOHAMMADNEZHAD mohsen GHAEMIAN Civil Engineering Department Sharif University of TechnologyTehran11155-9313Iran Faculty of Civil Water and Environmental EngineeringShahid Beheshti UniversityTehran11155-9313Iran

Seismic modeling of massive structures requires special caution,as wave propagation effects significantly affect the *** becomes more crucial when the path-dependent behavior of the material is *** coexistence of these conditions renders numerical earthquake analysis of concrete dams ***,a finite element model for a comprehensive nonlinear seismic simulation of concrete gravity dams,including realistic soil-structure interactions,is introduced.A semi-infinite medium is formulated based on the domain reduction method in conjunction with standard viscous *** representation of radiation damping in a half-space medium and wave propagation effects in a massed foundation are verified using an analytical solution of vertically propagating shear waves in a viscoelastic half-space domain.A rigorous nonlinear finite element model requires a precise description of the material ***,a microplane-based anisotropic damage-plastic model of concrete is formulated to reproduce irreversible deformations and tensorial degeneration of concrete in a coupled and rate-dependent ***,the Koyna concrete gravity dam is analyzed based on different assumptions of foundation,concrete response,and reservoir *** between responses obtained based on conventional assumptions with the results of the presented comprehensive model indicates the significance of considering radiation damping and employing a rigorous constitutive material model,which is pursued for the presented model.

关键词： soil-structure interaction massed foundation radiation damping anisotropic damage

Markovnikov addition of vinyl acetate with azoles catalyzed by potassium tert-butoxide

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2011年第4期22卷 417-420页

作者： Mazaahir Kidwai Neeraj Kumar Mishra Anwar jahan Green Chemistry Research Laboratory Department of ChemistryUniversity of DelhiDelhi-110007India

A simple and efficient methodology for Markovnikov addition of azoles with vinyl acetate catalyzed by potassium tert-butoxide is described.N-heterocyclic compounds are synthesized from simple and commercially availabl... 详细信息

关键词： Markovnikov addition Potassium tert-butoxide N-Heterocyclic compounds

An efficient aerodynamic shape optimization of blended wing body UAV using multi-fidelity models

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2018年第6期31卷 1165-1180页

作者： Parviz MOHAMMAD ZADEH mohsen SAYADI Faculty of New Sciences and Technologies University of Tehran

This paper presents a novel optimization technique for an efficient multi-fidelity model building approach to reduce computational costs for handling aerodynamic shape optimization based on high-fidelity simulation models. The wing aerodynamic shape optimization problem is solved by dividing optimization into three steps—modeling 3D（high-fidelity） and 2D（lowfidelity） models, building global meta-models from prominent instead of all variables, and determining robust optimizing shape associated with tuning local meta-models. The adaptive robust design optimization aims to modify the shape optimization process. The sufficient infilling strategy—known as adaptive uniform infilling strategy—determines search space dimensions based on the last optimization results or initial point. Following this, 3D model simulations are used to tune local meta-models. Finally, the global optimization gradient-based method—Adaptive Filter Sequential Quadratic Programing（AFSQP） is utilized to search the neighborhood for a probable optimum point. The effectiveness of the proposed method is investigated by applying it, along with conventional optimization approach-based meta-models, to a Blended Wing Body（BWB） Unmanned Aerial Vehicle（UAV）. The drag coefficient is defined as the objective function, which is subjected to minimum lift coefficient bounds and stability constraints. The simulation results indicate improvement in meta-model accuracy and reduction in computational time of the method introduced in this paper.

关键词： Adaptive filter sequential quadratic programing(AFSQP) Adaptive robust meta-model Aerodynamic shape optimization Blended wing body(BWB) Move limit strategy Unmanned aerial vehicle(UAV)

Open charm mesons and charmonia in magnetized strange hadronic matter

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2022年第8期46卷 91-113页

作者： Amal jahan C.S. Amruta Mishra Department of Physics Indian Institute of TechnologyNew Delhi-110016India

We investigate the in-medium masses of open charm mesons(D(D^(0),D^(+)),■(■^(0),D^(-)),D_(s)(D_(s)^(+),D_(s)^(-)))and charmonium states(J/ψ,ψ(3686),ψ(3770),χ_(c0),χ_(c2)) in strongly magnetized isospin asymmetric strange hadronic matter using a chiral effective *** the presence of a magnetic field,the number and scalar densities of charged baryons have contributions from Landau energy *** mass modifications of open charm mesons result from their interactions with nucleons,hyperons,and the scalar fields(the non-strange field σ,strange field C and isovector field δ) in the presence of a magnetic *** mass modifications of the charmonium states result from the modification of gluon condensates in a medium simulated by the variation in the dilaton field(χ) in the chiral effective *** effects of finite quark masses are also incorporated in the trace of the energy-momentum tensor in quantum chromodynamics to investigate the mass shifts of charmonium *** in-medium masses of open charm mesons and charmonia are observed to decrease with an increase in baryon *** charged D^(+),D^(-),Z_(s)^(+),and D_(s)^(-)mesons have additional positive mass shifts due to Landau quantization in the presence of a magnetic *** effects of the strangeness fraction are observed to be more dominant for ■ mesons compared with D *** mass shifts of charmonia are observed to be larger in hyperonic media compared with nuclear media when the effect of the finite quark mass term is *** medium mass modifications can have observable consequences on the production of the open charm mesons and charmonia in high-energy asymmetric heavy-ion collision experiments.

关键词： open charm mesons charmonium states strange hadronic matter magnetic field heavy-ion collision chiral effective model

Flow correction control with electromagnetically induced preform resting process

在线全文

学校读者我要写书评

暂无评论

Advances in Manufacturing 2019年第2期7卷 199-208页

作者： mohsen Poorzeinolabedin Kemal Levend Parnas Department of Mechanical Engineering Middle East Technical University Ankara Turkey Leopar Composite Engineering and Consulting Services Ltd. Ankara Turkey Department of Mechanical Engineering TED University Ankara Turkey

Resin flow correction control with electromagnetic field source, a new variation of the vacuum-assisted resin transfer molding (VARTM) process called electromagnetically induced preform resting (EIPR) for dynamical resin flow controlling is introduced to manipulate the flow front and local permeability to prevent the formation of dry spots. This paper proposes an active and real-time flow control approach that is implemented during the composite laminate infusion. The EIPR process applies an electromagnetic field source to pinch (raise) and vibrate the upper flexible mold to rest the fiber preform and increase the local permeability. Vibration action delivers the fluid through the preform. The EIPR process includes a new and creative upper flexible vacuum bag with embedded elements to lift and create local vibrations via an automated gantry system. The control methodology is performed by tracking the flow front with a real-time correction. System capability is demonstrated with three configurations of preform of different preform permeabilities in each experiment. A low permeability preform is employed in these configurations to disturb the flow pattern and cause an artificial problem or pseudo problem during the filling process. The results indicate that this system fills the mold completely and reduces the filling time without any dry spots and therefore creates no waste material.

关键词： Resin flow Process monitoring On-line flow control Vacuum-assisted resin transfer molding

Influence of welding speed on microstructure formation in friction-stir-welded 304 austenitic stainless steels

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

International Journal of Minerals,Metallurgy and Materials 2020年第11期27卷 1517-1524页

作者： mohsen Hajizadeh Sajjad Emami Tohid Saeid Faculty of Mechanical Engineering Sahand University of TechnologyTabrizIran Faculty of Materials Engineering Sahand University of TechnologyTabrizIran

The influence of welding speed on the joint microstructures of an austenitic stainless steel(ASS)produced by friction stir welding(FSW)was *** FSW process was conducted using a rotational speed of 400 r/min and welding speeds of 50 and 150 mm/*** study was carried out using electron backscattered diffraction(EBSD)technique in different regions of the resultant stir zones(SZs).The results show that the texture of the advancing side(AS)was mainly composed of C{001}〈110〉and cube{001}〈100〉texture components along with partial B/B{112}〈110〉*** from the AS toward the center and the retreating side(RS),the cube texture component disappeared and the A;/A*{111}(112)component developed and predominated the other *** welding speed greatly affected and decreased the intensity of the textures in the resultant ***,higher welding speed(lower heat input)resulted in lower frequency of cube texture in the AS.

关键词： friction stir welding stainless steels welding speed dynamic recovery shear texture continuous dynamic recrystallization

In vitro antilithiatic activity of the hydro-alcoholic extract of Cinnamomum zeylanicum Blume bark on calcium oxalate crystallization

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Medicine 2019年第4期17卷 273-281页

作者： Sana Zaki Nasreen jahan Mohd Kalim Ghausia Islam Department of Ilmus Saidla (Pharmacy) Glocal College of Unani Medicine Glocal University Saharanpur 247001 UP India Department of llmul Advia (Pharmacology) National Institute of Unani Medicine Rajiv Gandhi University of Health Sciences Bengaluru 560091 Karnataka India Department of Preventive and Social Medicine Ajmal Khan Tibbiya College Aligarh Muslim University Aligarh 202002 UP India

Objective: The study examines the effect of the hydro-alcoholic extract of Cinnamomum zeylanicum Blume bark on crystallization of calcium oxalate. Methods: The antilithiatic effect of various concentrations of the hydro-alcoholic extract of C. zeylanicum was investigated at various stages of stone formation, using Cystone as a stan da rd refere nee drug. The effect on calcium oxalate crystallization was evaluated by measuring the change in turbidity over time, during crystal nucleation, growth and aggregation, in the metastable solution of calcium chloride and sodium oxalate. The slope from the change in turbidity over time was measured using a spectrophotometer at 620 and 214 nm in respective tests. The inhibition rate was estimated by comparing turbidity in the presence and absence of extract. Crystals formed under experimental conditions were observed under a light microscope, and number and shape of the crystals were assessed in a randomly selected field. Phytochemical analysis and high-performance thin-layer chromatography of the extract was also carried out. Results: C. zeylanicum significantly reduced crystal nucleation at concentrations of 4, 8 and 10 mg/mL (P< 0.001). The inhibition percentage of crystal growth was between 28.30% and 92.46% in the presence of C. zeylanicum extract and from 20.76% to 64.15% with various concentrations of Cystone. The maximum inhibition of crystal growth was obtained from C. zeylanicum at 2 mg/mL (92.46%). Microscopic examination revealed a reduction in the number and size of crystals. In the aggregation assay, the inhibition percentage of C. zeylanicum was between 16.27% and 100%, while Cystone was from -214.68% to 100% at different concentrations. The highest (100%) inhibition of aggregation was found at 4 mg/mL of both the test and standard drugs. Conclusion: We found that C. zeylanicum hydro-alcoholic extract has notable inhibitory effects on various stages of crystallization, in terms of turbidity of solution, as well as

关键词： Antilithiatic activity Calcium oxalate Inorganic inhibitors In vitro Unani medicine