نتایج جستجو برای: transition metals

تعداد نتایج: 320706  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیراز - دانشکده علوم 1391

in this research we have studied the effect of some transition-metals (cu, ag and au) substitutions on two-electron reduction potential of flavins by application of dft method. all geometries have been optimized at blyp level of theory and “6-31+g** + lanl2dz” mixed basis set. the frequency job at the same method and basis sets has been performed to obtain gibbs free energy of compounds. it h...

Journal: :iranian journal of catalysis 0
abbas besharati-seidani department of chemistry, malek ashtar university of technology, tehran, iran.

tio2 nanoparticles, as a photocatalyst for oxidation of dimethyl methylphosphonate (dmmp) as an organophosphorus simulant of chemical warfare agent, were prepared by using sol-gel method. the prepared nanoparticles were then modified with transition metals in order to decrease the electron-hole recombination and increase the photocatalytic activity. transition metal ions including pt, pd and ni...

The one-third paradigm of PBE0 density functional, PBE0-1/3, has shown to be a successful method for various properties. In this paper, the applicability of PBE0-1/3 is put into broader perspective for transition metals chemistry. As a comparative study, the performance of PBE0 and PBE0-1/3 has been assessed for geometries and vibrational frequencies of some transition metal hydrides and transi...

Journal: :international journal of nanoscience and nanotechnology 2011
s. h. mahboobi a. meghdari n. jalili f. amiri

based on the fact the manipulation of fine nanoclusters calls for more precise modeling, the aim of this paper is to conduct an atomistic investigation for interaction analysis of particle-substrate system for pushing and positioning purposes. in the present research, 2d molecular dynamics simulations have been used to investigate such behaviors. performing the planar simulations can provide a ...

Journal: :international journal of nano dimension 0
ghazaleh allaedini department of chemical and process engineering, universitikebangsaan malaysia, 43600 bangi, selangor, malaysia. siti masrinda tasirin department of chemical and process engineering, universitikebangsaan malaysia, 43600 bangi, selangor, malaysia. payam aminayi chemical and paper engineering, western michigan university, kalamazoo, michigan, usa. zahira yaakob department of chemical and process engineering, universitikebangsaan malaysia, 43600 bangi, selangor, malaysia. meor zainal meor talib department of chemical and process engineering, universitikebangsaan malaysia, 43600 bangi, selangor, malaysia.

this review paper provides researcherwith a comprehensive information about the carbon nano tubes and the catalyst parameters that influences theproduction and morphology of the of carbon nano tubes.carbon nanotubes, referred to as cnts, are one of the most important materials used in electrical, mechanical, thermal, chemical and textile industries. since discovery of cnts in 1991, many scienti...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 2010
bhavna a. shah ajay v. shah pathik m. shah

salicylic acid-formaldehyde-m-cresol (sfm) terpolymer had been synthesized in dmf media by conventional method. the resulting resin had been characterized by ftir spectra, elemental and thermogravimetric analyses. the morphology of sfm resin had been studied by sem and optical photograph. various parameters like rate of equilibration, effect of ph on ion exchange capacity and effect of concentr...

Journal: :IMF working paper 2021

The energy transition requires substantial amounts of metals such as copper, nickel, cobalt and lithium. Are these a key bottleneck? We identify metal-specific demand shocks, estimate supply elasticities pin down the price impact in structural scenario analysis. Metal prices would reach historical peaks for an unprecedented, sustained period net-zero emissions scenario. total value production r...

Journal: :Philosophical transactions. Series A, Mathematical, physical, and engineering sciences 2015
Daniel R Slocombe Vladimir L Kuznetsov Wojciech Grochala Robert J P Williams Peter P Edwards

A qualitative account of the occurrence and magnitude of superconductivity in the transition metals is presented, with a primary emphasis on elements of the first row. Correlations of the important parameters of the Bardeen-Cooper-Schrieffer theory of superconductivity are highlighted with respect to the number of d-shell electrons per atom of the transition elements. The relation between the s...

اکبرزاده, هادی, زربخش, جواد, سقای‌ژیان, محمد, هاشمی‌فر, سیدجواد,

 Mechanical properties and stress-strain curves of Cu, Ag and Au single crystals are calculated using ab initio methods. Elastic and Plastic regions are scrutinized. Yield stress and slope of these curves can shed light on brittlenesss and ductility of these metals that prove Cu, despite its high ultimate tensile strength, is less ductile than Au and Ag. Analysis of topology of charge density a...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه فردوسی مشهد 1388

چکیده فارسی کاتالیست های 2و3 بیس (2و4و6 تری متیل فنیل) بوتان دی ایمین نیکل دی بروماید (a) و 2و3 بیس (سیکلو هگزیل) بوتان دی ایمین نیکل دی بروماید (b) و 2و3 بیس (فنیل) بوتان دی ایمین نیکل دی بروماید (c) تحت شرایط کنترل شده سنتز شدند و برای پلیمریزاسیون اتیلن مورد استفاده قرار گرفتند. متیل آلومینوکسان (mao) و تری ایزوبوتیل آلومینیوم (tiba) به ترتیب به عنوان کمک کاتالیست و رباینده آلودگی مورد است...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید