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Chinese Journal of Polymer Science 2007年第2期25卷 153-162页

作者： Mohammad Najafi vahid haddadi-asl Polymer Engineering Department Amirkabir University of TechnologyP.O.Box 15875-4413TehranIran

Different Ziegler-Natta catalysts were employed to polymerize ethylene. To investigate the influences of reaction parameters, namely Al/Ti molar ratio, hydrogen and processing parameters, i.e. ethylene pressure and temperature, a Taguchi experimental design was worked out. An L27 orthogonal array was chosen to take the above-mentioned parameters and relevant interactions into account. Response surface method was the tool used to analyze the experimental design results. Al/Ti, ethylene pressure and temperature were selected as experimental design factors, and catalyst activity and polymerization yield were the response parameters. Increasing pressure, due to an increment in monomer accessibility, and rising Al/Ti, because of higher reduction in the catalysts, cause an increase in both polymerization yield and catalyst activity. Nonetheless, a higher temperature, thanks to reducing ethylene solubility in the slurry medium and partially catalyst destruction, lead to a reduction in both response parameters. A synergistic effect was also observed between temperature and pressure. All catalyst activities will reduce in the presence of hydrogen. Molecular weight also shows a decline in the presence of hydrogen as a transfer agent. However, the polydispersity index remains approximately intact. Using SEM, various morphologies, owing to different catalyst morphologies, were seen for the polyethylene.

关键词： L27 Taguchi experimental design Response surface method Polyethylene polymerization Ziegler-Natta catalysts.

QUANTITATIVE EVALUATION OF ARRANGEMENT OF MONOMERS IN LINEAR BINARY COPOLYMERS USING A MONTE CARLO SIMULATION METHOD

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Chinese Journal of Polymer Science 2009年第2期27卷 195-208页

作者： Mohammad Najafi Mehdi Salami-Kalajahi vahid haddadi-asl Polymer Engineering Department Amirkabir University of TechnologyP.O.Box 15875-4413TehranIran National Petrochemical Company Petrochemical Research and Technology Company14358TehranIran

A Monte Carlo method was used to take thorough account of the influences of different reactivity ratios and initial feed compositions on copolymer *** model proves the lack of azeotropic behavior in systems in which r_A>1 and r_B<1 or vice versa;it is also able to calculate the drift in the copolymer properties:copolymer composition,and randomness ***,for each reactivity ratio pair given,there is a unique reaction conversion,at which macromolecules produced inherit their ...

关键词： Radical copolymerization Copolymer microstructure Copolymer composition Monte Carlo simulation Randomness parameter Copolymer heterogeneity Azeotrope point.

A COMPREHENSIVE MONTE CARLO SIMULATION OF STYRENE ATOM TRANSFER RADICAL POLYMERIZATION

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Chinese Journal of Polymer Science 2010年第4期28卷 483-497页

作者： Mohammad Najafi Hossein Roghani-Mamaqani Mehdi Salami-Kalajahi vahid haddadi-asl International Affairs Research Institute of Petroleum Industry(RIPI)***TehranIran Polymer Engineering Department Amirkabir University of TechnologyP.O.Box 15875-4413TehranIran

An optimized and high-performance Monte Carlo simulation is developed to take thorough account of four different cases of termination in styrene ATRP. According to the simulation results, the bimolecular termination rate constant sharply drops throughout the polymerization when either chain-length dependency of termination rate constant, gel effect, or both together is applied to the simulation. In addition, as expected, the initiator is quickly decomposed at the early stages of the polymerization. The concentration of the catalyst in lower oxidation state decreases at first and then plateaus at higher conversion; furthermore, the steady concentration of Ml^nY/L in the polymerization is the highest when the chain-lengthdependent diffusion-controlled termination rate constant is employed in the simulation. The rates of deactivation and chain end degradation reactions are also smaller in this case. Therefore, the fraction of dormant chains is higher throughout the reaction and consequently the portion of dead polymers decreases. Besides, molecular weight increases linearly with conversion; however, when neither gel effect nor chain-length dependency of termination rate constant is considered, the molecular weight deviates from linearity at the end of the reaction. The peak of chain length distribution shifts toward higher molecular weight too during the reaction. Finally, the molecular weight distribution broadens at higher conversion; however, the chain length distribution of polymers produced under conditions of applying chain-length-dependent diffusion-controlled termination rate constant is narrower.

关键词： Styrene ATRP Monte Carlo simulation Chain length distribution Gel effect Chain-length-dependent termination.

Quantum dense coding with gravitational cat states

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Communications in Theoretical Physics 2024年第3期76卷 84-90页

作者： Saeed haddadi Mehrdad Ghominejad Artur Czerwinski Faculty of Physics Semnan UniversityP.O.Box 35195-363SemnanIran Centre for Quantum Optical Technologies Centre of New TechnologiesUniversity of WarsawBanacha 2c02-097 WarszawaPoland

A protocol of quantum dense coding with gravitational cat states is *** explore the effects of temperature and system parameters on dense coding capacity and provide an efficient strategy to preserve the quantum advantage of dense coding for these *** results may open new opportunities for secure communication and insights into the fundamental nature of gravity in the context of quantum information processing.

关键词： quantum dense coding gravitational cat states quantum advantage

Quantum speedup and non-Markovianity of an atom in structured reservoirs:pseudomodes as a good description of environmental memory

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Communications in Theoretical Physics 2024年第8期76卷 60-66页

作者： Maryam Hadipour Soroush Haseli Saeed haddadi Faculty of Physics Urmia University of TechnologyUrmiaIran School of Physics Institute for Research in Fundamental Sciences(IPM)PO Box 19395-5531TehranIran Faculty of Physics Semnan UniversityPO Box 35195-363SemnanIran

Following the recent paper(Teittinen et al 2019 New J. Phys. 21 123041), one can see that in general there is no simple relation between non-Markovianity and quantum speed limit. Here, we investigate the connection between quantum speed limit time and non-Markovianity of an atom in structured environments(reservoirs) whose dynamics is governed by an exact pseudomode master equation(Garraway 1997 Phys. Rev. A 55 2290). In particular, we find an inverse relation between them, which means that the non-Markovian feature of the quantum process leads to speedup of evolution. Thus, there is a link between quantum speedup and memory effects for specific cases of dynamical evolution. Our results might shed light on the relationship between the speedup of quantum evolution and the backflow of information from the environment to the system.

关键词： quantum speed limit non-Markovianity pseudomode method structured environments

Sustainable ammonia synthesis:An in-depth review of non-thermal plasma technologies

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Journal of Energy Chemistry 2024年第9期96卷 1-38页

作者： vahid Shahed Gharahshiran Ying Zheng Department of Chemical and Biochemical Engineering Thompson Engineering BuildingWestern UniversityLondonON N6A 5B9Canada

Ammonia serves both as a widely used fertilizer and environmentally friendly energy source due to its high energy density,rich hydrogen content,and emissions-free ***,it offers convenient transportation and storage as a hydrogen *** dominant method used for large-scale ammonia production is the Haber-Bosch process,which requires high temperatures and pressures and is ***,non-thermal plasma offers an eco-friendly alternative for ammonia synthesis,gaining significant *** enables ammonia production at lower temperatures and pressures using plasma *** review provides insights into the catalyst and reactor developments,which are pivotal for promoting ammonia efficiency and addressing existing *** first,the reaction kinetics and mechanisms are introduced to gain a comprehensive understanding of the reaction pathways involved in plasma-assisted ammonia ***,the enhancement of ammonia synthesis efficiency is discussed by developing and optimizing plasma reactors and effective *** effect of other feeding sources,such as water and methane,instead of hydrogen is also ***,the challenges and possible solutions are outlined to facilitate energy-saving and enhance ammonia efficiency in the future.

关键词： Nitrogen fixation Ammonia synthesis NH_(3) Non-thermal plasma Ni Ru catalyst

Movement Trend Alterations in the Periaqueductal Gray(PAG)-Employed Ratbot Navigation Are Correlated with Stimulation Parameters

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Journal of Bionic Engineering 2024年第2期21卷 866-876页

作者： Sina Khajei Abed Khorasani Mohammad Reza Afarinesh vahid Sheibani Neuroscience Research Center Institute of NeuropharmacologyKerman University of Medical SciencesKerman***Iran Cognitive Neuroscience Research Center Institute of NeuropharmacologyKerman University of Medical SciencesKerman***Iran

In previous studies,Periaqueductal Gray(PAG)stimulation was used to stop ratbots from *** to the homology between the PAG and the intercollicular nucleus,which has been used for forward movement in birds,we investigated the possibility of PAG application to induce forward locomotion for the first *** a corridor maze,the traveled distances via PAG electrical stimulation were examined in nine Wistar male rats during three sessions.A custom-designed stimulator was developed to apply the *** results showed reductions in responses to stimulation over ***,the traveled distances had negative slopes during the consecutive trials(in 8 out of the 9 rats),and the slope mean was significantly different from *** was a strong correlation between the stimulation parameters(electric Charge per Phase(CPP)and the Number of Pulses(NP))and the observed *** negative Movement Slopes(MS)were highly correlated with the CPP and the NP,as the Pearson's linear correlation coefficients were−0.87 and−0.79,*** MS-CPP coefficients of determination(R-squared)were also between 0.76 and *** addition,the MS-NP coefficients of determination were between 0.63 and ***,it is concluded that the electrical stimulation parameters influence the behavioral outcomes ***,the PAG area may be considered a suitable candidate for forward locomotion control in the future if the area is harnessed effectively to prevent undesirable chaotic behaviors.

关键词： Periaqueductal Gray(PAG) Navigation Ratbot Animal-robot Forward locomotion Movement slope

The Anxiolytic and Antidepressant Effect of Stachys Lavandulifolia in the Experimental Pentylenetetrazole-Induced Rat Model of Acute Seizure

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World Journal of Traditional Chinese Medicine 2024年第1期10卷 114-120页

作者： vahid Azizi Farzin Allahyari Abdolkarim Hosseini Department of Animal Sciences Faculty of Life Sciences and BiotechnologyShahid Beheshti UniversityTehranIran

Objective:In traditional medicine,Stachys lavandulifolia or mountain tea has been used in the treatment of arthritis and rheumatoid arthritis.A leaf extract from this plant is also thought to be effective in treating epilepsy as well as other neurological *** assess the effect of *** extract(SLE),rats were exposed to a stress and anxiety model caused by *** and Methods:A challenge dose of pentylenetetrazole(PTZ)(60 mg/kg)was used to induce seizures in male Wistar rats(200-250 g).Animal treated with an intraperitoneal injection of either SLE(50 mg/kg)or sodium valproate(100 mg/kg)alone or in combination 30 min before PTZ *** effect of stress and anxiety was assessed using an open field test(OFT),forced swim test(FST),and elevated plus maze(EPM).At the end of the experiment,anesthesia was used to euthanize rats,and their blood serum was collected for measurements of glutathione(GSH),malondialdehyde(MDA),and GSH peroxidase(GPx).Results:In contrast to the control group,those treated with PTZ exhibited depressive *** 50 mg/kg,SLE provided protection against seizures induced by *** also reduced seizure-induced stress and anxiety,significantly improving FST,EPM,and OFT compared with the PTZ-treated *** decreasing MDA levels and restoring the antioxidant enzymes GSH and GPx,SLE treatment protects against seizure-induced anxiety and ***:SLE inhibits oxidative stress damage and seizure-induced stress by inhibiting seizures'inhibitory effects.

关键词： Anxiety behavior depression oxidative stress traditional medicine

Using X Social Networks (formerly Twitter) and web news mining to predict the measles outbreak

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Asian Pacific Journal of Tropical Medicine 2024年第4期17卷 188-190页

作者： Kia Jahanbin Mohammad Jokar vahid Rahmanian Department of Computer Engineering Yazd University YazdIran Faculty of Veterinary Medicine Karaj BranchIslamic Azad UniversityKarajIran Department of Public Health Torbat Jam Faculty of Medical SciencesTorbat JamIran

Measles,an infectious disease caused by the measles virus,remains a significant public health concern worldwide due to its highly contagious nature and potential for severe complications[1].In addition to symptoms such as high fever,cough,Koplik spots,and rash,measles can lead to serious complications including pneumonia and myocarditis,particularly in vulnerable populations such as young children[1,2].

关键词： Twitter web mining

Advancing sandstone reservoir compressibility prediction:A correlation-driven methodology

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Petroleum Research 2024年第2期9卷 273-279页

作者： Tarek Ganat Meftah Hrairi Amr Badawy vahid Khosravi Mohammed Abdalla Department of Petroleum Chemical Engineering Sultan Qaboos UniversityP.O.Box 50Al-Khod123MuscatOman Department of Mechanical and Aerospace Engineering International Islamic University MalaysiaP.O.Box 1050728Kuala LumpurMalaysia Reservoir Engineering Section Petronas Carigali SDN BHDP.O.Box 10500088Kuala LumpurMalaysia Department of Chemical and Petroleum Engineering Faculty of EngineeringTechnologyand Built EnvironmentUCSI University56000Kuala LumpurMalaysia Chemical&Petroleum Engineering United Arab Emirates UniversityP.O.Box No.15551Al AinUAE

This study presents a correlation-based approach for predicting the compressibility of sandstone reservoir *** study proposes a matrix of new empirical equations that significantly improve the precision of measuring the pore volume compressibility,with the most optimal fit of results based on a cubic polynomial *** accuracy of the calculations was validated through comparison with actual data using root mean square method,and the suggested correlations significantly enhance the precise prediction of rock compressibility in sandstone *** this study,the source of data collection is consolidated and unconsolidated sandstone from East Asia offshore ***,variations in compressibility with net overburden pressure over the course of the field's lifespan have been *** results demonstrate the application of regression analysis in establishing a network of linkages between independent and dependent *** proposed correlations for consolidated and unconsolidated sandstones offer a remarkable improvement in the accurate calculation of rock compressibility compared to traditional laboratory procedures,with an average error of 2.5%compared to 5-10%for laboratory *** approach of this study offers a cost-effective and time-efficient alternative to remarkedly enhance the overall performance of sandstone reservoirs in the oil and gas industry.

关键词： Compressibility Consolidated and unconsolidated sandstone Rock properties Rock mechanics