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One-pot synthesis of 1,3-thiazolidin-4-one using Bi(SCH_2COOH)_3 as catalyst

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Chinese Chemical Letters 2013年第5期24卷 389-391页

作者： Naser Foroughifar Sattar ebrahimi Faculty of Chemistry North Tehran BranchIslamic Azad University Department of Chemistry Malayer Branch Islamic Azad University

A catalytic multi-component reaction involving aromatic amine,aromatic aldehydes,mercapto acid as substrates and Bi（SCH_2COOH）_3 as catalyst under solvent free conditions,afforded thiazolidin-4-one in good *** efficiency of the catalyst was proved with a variety of substrates,ranging from electrondeficient to electron-rich aldehydes.

关键词： Thiazolidin-4-one Mercapto acid Multicomponent Thioglycolic acid

Strength performance of mortise and loose-tenon furniture joints under uniaxial bending moment

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Journal of Forestry Research 2014年第2期25卷 483-486页

作者： Mohammad Derikvand Ghanbar ebrahimi Department of Wood and Paper Science and Technology College of Natural ResourcesUniversity of Tehran

We determined the effects of adhesive type and loose tenon dimensions （length and thickness） on bending strength of T-shaped mor- tise and loose-tenon joints. Polyvinyl acetate （PVAc） and two-component polyurethane （PU） adhesives were used to construct joint specimens. The bending moment capacity of joints increased significantly with increased length and thickness of the loose tenon. Bending moment capacity of joints constructed with PU adhesive was approximately 13% higher than for joints constructed with PVAc adhesive. We developed a predictive equation as a function of adhesive type and loose tenon dimensions to estimate the strength of the joints constructed of oriental beech （Fagus orientalis L.） under uniaxial bending load.

关键词： bending moment capacity mortise and loose tenon loose tenon dimensions polyvinyl acetate two-component polyurethane

The combinatorics of Green＇s functions in planar field theories

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Frontiers of physics 2016年第6期11卷 1-23页

作者： Kurusch ebrahimi-Fard Frederic Patras ICMAT C/Nicolds Cabrera no. 13-15 28049 Madrid Spain. On leave from UHA Mulhouse France Univ. de Nice Labo. J-A. Dieudonnd UMR 7351 CNRS Parc Valrose 06108 Nice Cedex 02 France

The aim of this exposition is to provide a detailed description of the use of combinatorial algebra in quantum field theory in the planar setting. Particular emphasis is placed on the relations between different types of planar Green’s functions. The primary object is a Hopf algebra that is naturally defined on variables representing non-commuting sources, and whose coproduct splits into two half-coproducts. The latter give rise to the notion of an unshuffle bialgebra. This setting allows a description of the relation between full and connected planar Green’s functions to be given by solving a simple linear fixed point equation. We also include a brief outline of the consequences of our approach in the framework of ordinary quantum field theory.

关键词： planar field theory Green’s functions free probability Hopf algebra shuffle algebra partitions

Effect of ultrasonic irradiation on particle size,reagents consumption,and feed ash content in coal flotation

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International Journal of Coal Science & Technology 2020年第4期7卷 787-795页

作者： Hossein ebrahimi Mohammad Karamoozian Department of Mining Petroleum and GeophysicsShahrood University of TechnologyShahroodIran

Ultrasonic waves have a lot of use in the particle surface *** flotation is one of the methods associated with surface properties,this paper investigates the effect of these waves on performance,particle size,reagents,and feed ash content in coal *** accomplish this goal,coal samples in three size fractions,including coarse(-800 to+400μm),medium(-400 to+100 μm)and fine(-100μm)with various feed ash *** flotation experiments were evaluated by process indexes such as yield,combustible recovery,and selectivity *** results indicated the increasing of *** increasing was significant in medium ***,the results showed that in presence of ultrasonic waves,the collector and frother consumption *** also,applying ultrasonic waves would result more combustible recovery and selectivity *** ash selectivity index had the highest impact for high feed ash content.

关键词： Flotation Ultrasonic waves Coal Particle size Reagents Feed ash

Cooperative Neuro Adaptive Control of Leader Following Uncertain Multi-Agent Systems with Unknown Hysteresis and Dead-Zone

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Journal of Systems Science & Complexity 2020年第2期33卷 312-332页

作者： SHAHNAZI reza Department of Electrical Engineering Faculty of EngineeringUniversity of GuilanRasht ***Iran

In this paper,a cooperative adaptive control of leader-following uncertain nonlinear multiagent systems is *** communication network is weighted undirected graph with fixed *** uncertain nonlinear model for each agent is a higher-order integrator with unknown nonlinear functions,unknown disturbances and unknown input ***,the gains of input actuators are unknown nonlinear functions with unknown *** most common behaviors of input actuators in practical applications are hysteresis and *** this paper,backlash-like hysteresis and dead-zone are used to model the input *** universal approximation theorem proved for neural networks,the unknown nonlinear functions are *** unknown weights of neural networks are derived by proposing appropriate adaptive *** cope with modeling errors and disturbances an adaptive robust structure is *** Lyapunov synthesis approach not only all the adaptive laws are derived but also it is proved that the closed-loop network is cooperatively semi-globally uniformly ultimately bounded(CSUUB).In order to investigate the effectiveness of the proposed method,it is applied to agents modeled with highly nonlinear mathematical equations and inverted *** results demonstrate the effectiveness and applicability of the proposed method in dealing with both numerical and practical multi-agent systems.

关键词： Adaptive neural network backlash-like hysteresis dead-zone leader-following multi-agent systems weighted undirected graph

On the potential of alyssum as an herbal fiber to improve the filtration and rheological characteristics of water-based drilling muds

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Petroleum 2022年第4期8卷 509-515页

作者： Mohammad Amin ebrahimi Ali Sanati Department of Petroleum Engineering Amirkabir University of TechnologyTehranIran Petroleum and Petrochemical Engineering School Hakim Sabzevari UniversitySabzevarIran

Drilling muds play an important role in drilling and production operations so that the degree of success in such operations is determined by the proper design of these *** optimize drilling operations and avoid excessive expenditure,it is essential to prepare a drilling mud that is both cheap and *** additives are typically used in drilling systems to improve these fluids'capabilities in terms of hole cleaning capacity,filtration control,viscosity,yield point,heat transfer,***,environmental concerns,cost of production,and availability are always considered challenging *** study introduces an eco-friendly herbal fiber in powder and regular forms as a potential alternative to other chemical *** do so,alyssum homolocarpum seed mucilage was added with different concentrations to the water-based drilling muds,and its rheological behavior,filtration control,and the induced formation damage were examined and the optimum concentration was *** results of this study revealed the advantages of the drilling muds formulated with alyssum in terms of filtration control,rheology,formation damage,and greenness.

关键词： Drilling fluid alyssum Herbal fiber Rheology Filtration contro

Chemical-only reprogramming to pluripotency

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Frontiers in Biology 2016年第2期11卷 75-84页

作者： Behnam ebrahimi Yazd Cardiovascular Research Center Shahid Sadoughi University of Medical Sciences Yazd Iran

Direct reprogramming technology has emerged as an outstanding technique for the generation of induced pluripotent stem cells （iPSCs） and various specialized cells directly from somatic ceils of different species. Reprogramming techniques conventionally use viral vectors encoding transcription factors to induce fate conversion. However, the introduction of transgenes limits the therapeutic applications of the reprogrammed cells. To overcome safety-related concerns, small molecules offer some advantages over the existing methods for the control of gene expression and induction of cell fate conversion. Technical advances in optimizing concentrations, durations, structures, and combinations of small molecules make chemical reprogramming a safe and feasible method. This review provides a concise overview of cutting-edge findings regarding chemical-only reprogramming as one of the integration-free approaches to iPSC generation.

关键词： cellular reprogramming small molecule chemical reprogramming induced pluripotency regenerative medicine

Effect of Delay Time on Microstructural Evolution during Warm Rolling of Ti-Nb-IF Steel

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Journal of Materials Science & Technology 2004年第1期20卷 86-88页

作者： A. Najafi-zadeh R.ebrahimi Department of Materials Engineering Isfahan University of Technology Isfahan 84154 IranDepartment of Materials Engineering Isfahan University of Technology Isfahan 84154 Iran

The effect of delay time with constant first finishing pass temperature (800℃) has been investigated by means of multi-pass torsion tests on Ti-Nb-IF steel. All the tests have been carried out at a strain rate of 2 s-1 with 11 passes and 0.3 strain each pass. During the final pass, dynamic recrystallization occurs to a degree that depends on the delay time. In short interpass time (1 s) and at these temperatures (T≤800℃) there is not enough time to start static recrystallization, therefore, accumulation of strain occurs and after some passes, strain reaches a critical strain for starting dynamic recrystallization. In this study, the changes of mean flow stress during each pass and also the microstructural observation confirms that dynamic recrystallization occurs after some passes in ferrite phase of this steel. The stress-strain curves with constant temperature obtained by using a kinetic model and compensation of the increasing mean flow stress with decreasing temperature. Thus, this result also confirms that dynamic recrystallization occurs in warm rolling of this IF steel.

关键词： Warm rolling Perrite rolling Thermomechanical processing IF steels

Improved drought tolerance in Festuca ovina *** plant growth promoting bacteria

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Journal of Arid Land 2023年第6期15卷 740-755页

作者： Fateme RIGI Morteza SABERI Mahdieh ebrahimi Department of Range and Watershed Management Faculty of Water and SoilUniversity of ZabolZabol ***Iran

Numerous ecological factors influence a plant’s ability to live and grow,in which dryness is a substantial constraint on plant growth in arid and semi-arid *** response to a specific environmental stress,plants can use the most effective bacteria to support and facilitate their growth and ***,plant growth promoting rhizobacteria(PGPR)is widely used to reduce drought stress on plant *** this study,the effects of drought on Festuca ovina ***,growth,and nutrient absorption were investigated using PGPR in a factorial test with a completely random design under four water *** water content was kept at 100%FC(field capacity),70%FC(FC),50%FC,and 30%*** treatments were inoculated with Azotobacter vinelandii,Pantoea agglomerans+Pseudomonas putida,and a mixture of *** showed that the effects of drought stress were significantly reduced(P<0.05)when *** and ***+*** were used separately,however,the combined treatment of bio-fertilizers had a greater influence on seed germination than the single ***+*** under 30%FC condition resulted in higher increases in stem,root length,and plant dry *** highest uptake of nutrients was observed for the combined treatment of bio-fertilizers under 30%FC ***,the use of *** and ***+***,applied separately or combined,increased tolerance to drought stress in *** by increased germination indices,dry weight,stem length,and root *** of the beneficial effects of PGPR on the growth characteristics of plants under drought conditions and the reduction of negative effects of drought stress,inoculating *** seeds with Azotobacter and Pseudomonas is recommended to improve their growth and development characteristics under drought ***,as an affordable and environmentally friendly method,can improve the production of forage in water-stress rangelands.

关键词： bio-fertilizers element uptake drought stress rangeland water scarcity