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Acetalization of Carbonyl Compounds as Pentaerythritol Diacetals and Diketals in the Presence of Cellulose Sulfuric Acid as an Efficient, Biodegradable and Reusable Catalyst

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Chinese Journal of Chemistry 2012年第3期30卷 695-698页

作者： Shaterian, hamid reza Rigi, Fatemeh Department of Chemistry Faculty of Sciences University of Sistan and Baluchestan PO Box 98135-674 Zahedan Iran

This paper reports a practical and green method for the acetalization of carbonyl compounds as pentaerythritol diacetals and diketals derivatives using cellulose sulfuric acid as a biodegradable and reusable solid aci... 详细信息

关键词： synthetic method, aldehyde, cellulose sulfuric acid pentaerythritol, solvent-free, acetalization

Characterization of Cysteine Coated Magnetite Nanoparticles as MRI Contrast Agent

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Nano-Micro Letters 2012年第3期4卷 180-183页

作者： reza Ahmadi Ning Gu hamid reza Madaah Hosseini Department of Materials Science and Engineering Sharif University of Technology Research Center for Molecular and Cellular Imaging Tehran University of Medical Sciences Jiangsu Key Laboratory of Biomaterials and Devices

In this work,a kind of stabilized ferrofluid based on magnetite nanoparticles(mean core and its coating size about 21.9 and 1.6 nm,respectively)was synthesized via coprecipitation *** was used as surfactant due to its proper conjunction to the surface of magnetite *** density and synthesized ferrofluids were characterized by using transmission electron microscope,thermogravimetry analysis,dynamic light scattering and fourier transform infrared spectroscopy *** resonance imaging studies show that the synthesized ferrofluid can be used as a potential contrast enhancement agent especially for imaging lymphatic system.

关键词： Magnetite Co-precipitation Cysteine MRI

Complementary Inequalities to Improved AM-GM Inequality

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Acta Mathematica Sinica,English Series 2017年第12期33卷 1609-1616页

作者： hamid reza MORADI Mohsen Erfanian OMIDVAR Department of Mathematics Mashhad Branch Islamic Azad University Mashhad Iran

Following an idea of Lin, we prove that if A and B are two positive operators such that 0 〈 mI 〈 A 〈 m＇I ≤ M＇I ≤B 〈 MI, then Ф^2（A＋B/2）≤K^2（h）/（1＋（logM＇/m＇）^2/8）^2Ф^2（A#B）,and Ф^2（A＋B/2）≤K^2（h）/（1＋（logM＇/m＇）^2/8）^2（Ф（A）#Ф（B））^2,where K（h） = （h＋1）2 /4h and h = M and Ф is a positive unital linear map.

关键词： Operator inequalities positive linear maps operator norm Kantorovich inequality Wielandt inequality

Modification of RDX and HMX crystals in procedure of solvent/anti-solvent by statistical methods of Taguchi analysis design and MLR technique

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Defence Technology（防务技术） 2018年第1期14卷 59-63页

作者： hamid reza Pouretedal Sajjad Damiri Abolfazl Shahsavan Faculty of Applied Chemistry Malek-ashtar University of Technology (MUT)

Many of the physical and functional properties of RDX and HMX explosives are related to the crystalline structure of these materials. Crystalline defects affect the quality of the explosives. Therefore, in order to enhance the quality of these materials, it is necessary to form crystals with the lowest defects. In this research, we report the optimization of recrystallization process of RDX and HMX by statistical techniques. The solvent/anti-solvent procedure was used for recrystallization of HMX and RDX particles. The four parameters of i) ratio of anti-solvent to solvent, ii) ratio of solute to solvent, iii) aging time, and iv)cooling rate of mixture, were optimized by Taguchi analysis design. Taguchi L16 orthogonal array was used with sixteen rows corresponding to the number of tests in four columns at four levels. The apparent density of recrystallized of RDX and HMX particles was considered as the quality characteristic with the concept of "the larger-the-better". The obtained graphs showed that the studied parameters were optimized in ratio 1:1 for anti-solvent to solvent, ratio 0.1 g,m L^(-1) for solute to solvent, aging time of 2 h and cooling rate of 1℃,min^(-1). Also, the correlation between the investigated parameters and apparent density of crystals were studied by multiple linear regressions(MLR) method for obtaining a model of prediction of apparent density. The P-values were indicated that in confidence level of 95%, the null hypothesis is rejected and a meaningful addition is observed in the proposed model.

关键词： HMX RDX Solvent/anti-solvent Taguchi analysis Apparent density

Evaluating the characteristics of geological structures in karst groundwater inflow, Nowsud Tunnel

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Journal of Mountain Science 2024年第10期21卷 3434-3452页

作者： BAYAT Narges SADEGHI Erfan NASSERY hamid reza Department of Minerals and Groundwater Resources Faculty of Earth SciencesShahid Beheshti UniversityEvin AveTehran ***Iran Ministry of Energy Kordestan ExpyTehran ***Iran

Highly permeable geological structures such as dissolution channels, open fractures, and faults create environmental challenges regard to hydrological and hydrogeological aspects of underground construction, often causing significant groundwater inflow during drilling due to the limitations of empirical and analytical methods. This study aims to identify the geological factors influencing water flow into the tunnel. High-flow zones' geological features have been identified and examined for this purpose. According to the geological complexity of the Nowsud tunnel, presence of different formations with different permeability and karstification have led to a high volume of underground inflow water (up to 4700 L/s) to the tunnel. The Nowsud tunnel faces significant geological and hydrogeological challenges due to its passage through the Ilam formation's LI2 unit, characterized by dissolution channels, faults, and fractures. The highest inflow rate (4700 L/s) occurred in the Hz-9 zone within the Zimkan anticline. The relationship between geological features and groundwater inflow indicates that anticlines are more susceptible to inflow than synclines. Additionally, different types of faults exhibit varying hydraulic effects, with strike-slip faults having the most significant impact on groundwater inflow, thrust faults conducting less water into the tunnel, and inflow through normal faults being negligible compared to the other two types of faults. The novelty of this paper lies in its detailed analysis of geological features influencing groundwater inflow into the Nowsud tunnel, providing empirical data on high-flow zones and differentiating the hydraulic effects of various fault types, which enhances the understanding and prediction of groundwater inflow in underground constructions.

关键词： Geological structures Groundwater inflow Hydrogeology Nowsud tunnel Karst

Effects of preparation and operation conditions on precipitated iron nickel catalysts for Fischer-Tropsch synthesis

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Journal of Natural Gas Chemistry 2010年第3期19卷 341-353页

作者： Mostafa Feyzi Ali Akbar Mirzaei hamid reza Bozorgzadeh Department of Chemistry Faculty of SciencesUniversity of Sistan & Baluchestan Research Institute of Petroleum Industry(RIPI) Gas Division

Iron nickel oxide catalysts were prepared using co-precipitation procedure and studied for the conversion of synthesis gas to light *** particular,the effects of a range of preparation variables such as Fe/Ni molar ratios of the precipitation solution,precipitate aging times,calcination conditions,different supports and loading of optimum support on the structure of catalysts and their catalytic performance for the tested reaction were *** was found that the catalyst containing 40%Fe/60%Ni/40wt%Al 2O3 ,which was aged for 180 min and calcined at 600 ℃ for 6 h was the optimum modified *** catalytic performance of optimal catalyst has been studied in different operation conditions such as reaction temperatures,H2 /CO molar feed ratios and reaction total *** of both precursors and calcined catalysts was carried out by powder X-ray diffraction（XRD）,scanning electron microscopy（SEM）,Brunauer-Emmett-Teller（BET） surface area measurements,thermal analysis methods such as thermal gravimetric analysis（TGA） and differential scanning calorimetry（DSC）.

关键词： iron nickel light olefins Fischer-Tropsch operation conditions

Effect of Oxidizing Atmosphere on the Surface of Titanium Dental Implant Material

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Journal of Bionic Engineering 2019年第6期16卷 1052-1060页

作者： Mohammad Khodaei Akram Alizadeh hamid reza Madaah Hosseini Department of Materials Science and Engineering Golpayegan University of TechnologyGolpayegan 87717-65651Iran Department of Tissue Engineering School of Advanced TechnologiesShahrekord University of Medical SciencesShahrekord 88157-13471Iran Department of Materials Science and Engineering Sharif University of TechnologyTehran 14588-89694Iran

Direct oxidation is a simple and effective method for titanium surface *** this research,a titanium sample was directly oxidized at the high temperature in two different atmospheres,air and pure oxygen,to obtain better atmosphere for titanium surface *** results of the Raman spectroscopy indicated that in both atmospheres,the rutile bioactive phase(TiO2)has been formed on the titanium *** results of X-ray diffraction(XRD)also revealed that the surface of oxygen-treated sample was composed of the rutile phase and titanium monoxide(TiO),while at the surface of the air-treated sample,the rutile phase and titanium dioxide had been ***,the results of Field Emission Scanning Electron Microscopy(FE-SEM)showed that by the surface treatment of titanium in both atmospheres,some micro-features including cracks thinner than 30 nm were formed on the *** of more apatite forming ability and fewer water contact angle and more L-929 cell attachment of the air-treated titanium,it seemed that air,in comparison to the pure oxygen,is more promising atmosphere for the direct oxidation of titanium and improving its biofunctionalization.

关键词： titanium implant surface treatment direct oxidation anatase rutile biomedical-materials

Global Mittag-Leffler stability for fractional-order coupled systems on network without strong connectedness

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Science China(Information Sciences) 2020年第3期63卷 184-194页

作者： Xin MENG Yonggui KAO hamid reza KARIMI Cunchen GAO School of Mathematical Sciences Ocean University of China Department of Mechanical Engineering Politecnico di Milano Department of Mathematics Harbin Institute of Technology (Weihai)

This study investigates the global Mittag-Leffler stability(MLS) problem of the equilibrium point for a new fractional-order coupled system(FOCS) on a network without strong connectedness. In particular, an integer-order coupled system is extended into the FOCS on a complex network without strong connectedness. Based on the theory of asymptotically autonomous systems and graph theory, sufficient conditions are derived to ensure the existence, uniqueness, and global MLS of the solutions of this FOCS on a network. Finally, a numerical example is provided to demonstrate the validity and potential of the proposed method for studying the MLS of FOCSs.

关键词： global Mittag-Leffler stability fractional-order coupled system connectedness

Characteristics of turbulent flow in 3-D pools in the presence of submerged rigid vegetation in channel bed

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Journal of Hydrodynamics 2024年第1期36卷 158-169页

作者： Kourosh Nosrati Hossein Afzalimehr Jueyi Sui hamid reza Reisifar Natural Disasters Prevention Research Center Faculty of Civil EngineeringIran University of Science and TechnologyTehranIran School of Engineering University of Northern British ColumbiaPrince GeorgeCanada

In this study,the interaction between 3-D bedforms and submerged rigid vegetation has been *** laboratory experiments were conducted to study the distribution of flow velocity,Reynolds shear stress,turbulent kinetic energy,and skewness coefficients for a constant density of *** showed that the velocity profile in the pool section deviates from those in the upstream section of the *** has been found that the dip parameter varied between 0.6H and 0.9H depending on various factors including bed roughness,vegetation distribution,and pool entrance/exit ***,scattered vegetation in the pool and differences in slopes created non-uniform flow ***,in the wake region behind each vegetated element,flow velocity reduced significantly,and small-scale eddies are formed,causing increased *** decreasing the entrance slope and bed roughness,relatively uniform flow and weaker turbulence was resulted,but the random distribution of vegetated elements counteracted this balance and intensified *** the decrease in the pool entrance slope,the contribution of sweep event decreased and the contribution of ejection event increased.

关键词： Submerged rigid vegetation 3-D pool Reynolds shear stress skewness coefficients