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Synthesis,gas adsorption and reliable pore size estimation of zeolitic imidazolate framework-7 using CO_2 and water adsorption

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Chinese Journal of Chemical Engineering 2017年第5期25卷 595-601页

作者： Mahdi niknam shahrak morteza niknam shahrak Akbar Shahsavand Nasser Khazeni Xiaofei Wu Shuguang Deng Chemical Engineering Department Faculty of EngineeringQuchan University of Advanced Technology Chemical Engineering Department Faculty of EngineeringFerdowsi University of Mashhad Chemical Engineering Department New Mexico State University Chemical Engineering Department Arizona State University

Reliable estimation of the pore size distribution(PSD) in porous materials such as metal–organic frameworks(MOFs) and zeolitic imidazolate frameworks(ZIFs) is crucial for accurately assessing adsorption capacity and corresponding selectivity. In this study, the so-called zeolitic imidazolate framework-7(ZIF-7) is successfully synthesized via relatively fast and convenient microwave technique. The morphology and structure of the obtained MOF were characterized by XRD, SEM and N_2 and CO_2adsorption/desorption isotherms at 77 K and0 °C respectively. Then, to determine the PSD of the fabricated MOF, carbon dioxide isotherms are experimentally measured at various temperatures up to atmospheric pressure. Afterward, the experimental CO_2 isotherms data are utilized in two recently proposed in-house algorithms of SHN1 and SHN2 to extract the true PSD of manufactured ZIF-7. The obtained results revealed that median pore diameter of the fabricated ZIF-7 is estimated around 0.404 nm and 0.370 nm by using CO_2 isotherms at 273 K and 298 K respectively. These values are in good agreement with the real pore diameter of 0.42 nm. Moreover, experimental data of water adsorption isotherms over four different MOFs, borrowed from literature, are employed to illustrate further effectiveness of the above algorithms on successful determination of the corresponding pore size distributions. All predicted PSDs are proved to be in good agreement with those obtained from independent methods such as topology and morphology studies.

关键词： ZIF-7 Metal–organic framework Size distribution Adsorption CO2 capture Gas

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Using satellite-derived land surface temperatures to clarify the spatiotemporal warming trends of the Alborz Mountains in northern Iran

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Journal of Mountain Science 2024年第2期21卷 449-469页

作者： ROSHAN Gholamreza SARLI Reza GHANGHERMEH Abdolazim TAHERIZADEH Mehrnoosh niknam Arman Department of Geography Golestan UniversityGorgan 49138-15759Iran Department of Forest Resources Management Faculty of ForestryUniversity of Agriculture in KrakowAL.29 Listopada 4631-425 KrakówPoland Department of Geoinformatics Physical and Environmental GeographyUniversity of SzegedSzeged 6722Hungary

The Alborz Mountains are some of the highest in Iran,and they play an important role in controlling the climate of the country’s northern *** land surface temperature(LST)is an important variable that affects the ecosystem of this *** study investigated the spatiotemporal changes and trends of the nighttime LST in the western region of the Central Alborz Mountains at elevations of 1500-4000 m above sea *** data were extracted for the period of 2000-2021,and the Mann-Kendall nonparametric test was applied to evaluating the changes in the *** results indicated a significant increasing trend for the monthly average LST in May-August along the southern *** the northern and southern aspects showed decreasing trends for the monthly average LST in October,November,and March and an increasing trend in other *** all elevations,the average decadal change in the monthly average LST was more severe along the southern aspect(0.60°C)than along the northern aspect(0.37°C).The LST difference between the northern and southern aspects decreased in the cold months but increased in the hot *** the same elevation,the difference in the lapse rate between the northern and southern aspects was greater in the hot months than in the cold *** increasing elevation,the lapse rate between the northern and southern aspects *** change was concluded to greatly decrease the difference in LST at different elevations for April-July.

关键词： Global warming Mountainous areas Lapse rate Surface air temperatures Alborz

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Improved CO2 capture performances of ZIF-90 through sequential reduction and lithiation reactions to form a hard/hard structure

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Frontiers of Chemical Science and Engineering 2020年第3期14卷 425-435页

作者： Mahboube Ghahramaninezhad Fatemeh Mohajer Mahdi niknam shahrak Department of Chemical Engineering Quchan University of TechnologyQuchan 94771-67335Iran

Post-synthetic functionalization or modification has been regarded as a promising strategy to treat surfaces of adsorbents for their applications in targeted adsorption and separation *** this work,a novel microporous adsorbent for carbon capturing was developed via functionalization of zeolitic imidazolate framework-91(ZIF-91)to generate a hard/hard(metal-oxygen)structure named as lithium-modified ZIF-91(ZIF-91-OLi compound).To this purpose,the ZIF-91 compound as an intermediate product was achieved by reduction of ZIF-90 in the presence of NaBH4 as a good reducing ***,acidic hydrogen atoms in the hydroxyl groups of ZIF-91 were exchanged with lithium cations via reaction of n-BuLi compound as an organo lithium agent through an appropriate *** particular,the as-synthesized ZIF-91-OLi operated as an excellent electron-rich center for CO2 adsorption through trapping the positive carbon centers in the CO2 *** calculations revealed that the presence of lithium over the surface of ZIF-91-OLi adsorbent plays an effective role in double enhancement of CO2 storage via creating a strong negative charge center at the oxygen atoms of the imidazolate linker as a result of the lithium/hydrogen exchange ***,the selectivity of CO2/N2 was investigated at different temperatures,revealing the ZIF-91-OLi as a selective adsorbent for industrial application.

关键词： hard/hard structure acidic hydrogen ZIF-91 carbon capture ZIF-91-OLi

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Application of honey-bee mating optimization on state estimation of a power distribution system including distributed generators

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第12期9卷 1753-1764页

作者： Taher niknam Electronic and Electrical Department Shiraz University of TechnologyShirazIran

We present a new approach based on honey-bee mating optimization to estimate the state variables in distribution networks including distributed generators. The proposed method considers practical models of electrical equipments such as static var compensators, voltage regulators, and under-load tap changer transformers, which have usually nonlinear and discrete characteristics. The feasibility of the proposed approach is demonstrated by comparison with the methods based on neural networks, ant colony optimization, and genetic algorithms for two test systems, a network with 34-bus radial test feeders and a realistic 80-bus 20 kV network.

关键词： Distributed generators (DGs) State estimation Honey-bee mating optimization (HBMO)

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Silica-bonded N-propylsulfamic acid as a recyclable catalyst for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones

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Chinese Chemical Letters 2011年第1期22卷 69-72页

作者： Khodabakhsh niknam Nasrolah Jafarpour Ebrahim niknam Department of Chemistry Islamic Azad UniversityGachsaran BranchGachsaranIran

2,3-Dihydroquinazolin-4（1H）-one derivatives are synthesized via a one-pot, three component reaction of isatoic anhydride and an aromatic aldehyde with ammonium acetate or primary amine catalyzed by silica-bonded N-p... 详细信息

关键词： Silica-bonded N-propylsulfamic acid 2,3-Dihydroquinazolin-4(1H)-ones Isatoic anhydride Aldehydes

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A hybrid evolutionary algorithm for distribution feeder reconfiguration

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Science China(Technological Sciences) 2010年第4期53卷 950-959页

作者： Taher niknam Ehsan AZAD FARSANI Electronic and Electrical Department Shiraz University of Technology

This paper presents a new method to reduce the distribution system loss by feeder *** new method combines self-adaptive particle swarm optimization(SAPSO) with shuffled frog-leaping algorithm(SFLA) in an attempt to find the global optimal solutions for the distribution feeder reconfiguration(DFR).In PSO algorithm,appropriate adjustment of the parameters is cumbersome and usually requires a lot of time and ***,a self-adaptive framework is proposed to improve the robustness of *** SAPSO the learning factors of PSO coevolve with the *** is combined with the SAPSO algorithm to improve its *** proposed algorithm is tested on two distribution test *** results of simulation show that the proposed algorithm is very powerful and guarantees to obtain the global optimization in minimum time.

关键词： self-adaptive particle swarm optimization(SAPSO) discrete particle swarm optimization(DPSO) binary particle swarm optimization(BPSO) shuffled frog-leaping algorithm(SFLA) evolutionary algorithms(EA) distribution feeder reconfiguration(DFR)

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An efficient hybrid evolutionary optimization algorithm based on PSO and SA for clustering

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第4期10卷 512-519页

作者： Taher niknam Babak AMIRI Javad OLAMAEI Ali AREFI Electronic and Electrical Engineering Department Shiraz University of TechnologyShirazIran Information Technology Department Islamic Azad University-Fars Science and Research BranchShiraz Iran Technical Engineering Department Islamic Azad University-South Tehran BranchTehran Iran Power Engineering Group Department of Electrical and Computer Engineering Tarbiat Modares UniversityTehran Iran

The K-means algorithm is one of the most popular techniques in clustering. Nevertheless, the performance of the Kmeans algorithm depends highly on initial cluster centers and converges to local minima. This paper proposes a hybrid evolutionary programming based clustering algorithm, called PSO-SA, by combining particle swarm optimization (PSO) and simulated annealing (SA). The basic idea is to search around the global solution by SA and to increase the information exchange among particles using a mutation operator to escape local optima. Three datasets, Iris, Wisconsin Breast Cancer, and Ripley's Glass, have been considered to show the effectiveness of the proposed clustering algorithm in providing optimal clusters. The simulation results show that the PSO-SA clustering algorithm not only has a better response but also converges more quickly than the K-means, PSO, and SA algorithms.

关键词： Simulated annealing (SA) Data clustering Hybrid evolutionary optimization algorithm K-means clustering Parti-cle swarm optimization (PSO)

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Preparation of Silica-bonded Propyl-diethylene-triamine-N- sulfamic Acid as a Recyclable Catalyst for Chemoselective Synthesis of 1,1-Diacetates

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Chinese Journal of Chemistry 2011年第11期29卷 2361-2367页

作者： Nouri Sefat, Maryam Deris, Abdolah niknam, Khodabakhsh Chemistry Department Faculty of Sciences Persian Gulf University Bushehr 75169 Iran

A simple and efficient procedure for the preparation of silica-bonded propyl-diethylene-triamine-N-sulfamic acid （SPDTSA） by reaction of 3-diethylenetriamine-propylsilica （DTPS） and chlorosulfonic acid in chloroform is described. Silica-bonded propyl-diethylene-triamine-N-sulfamic acid is employed as a recyclable catalyst for the synthesis of 1,1-diacetates from aromatic aldehydes and acetic anhydride under mild and solvent-free conditions at room temperature. Catalyst could be recycled for several times without any additional treatment.

关键词： silica-bonded propyl-diethylene-triamine-N-sulfamic acid 1,1-diacetates aromatic aldehydes catalyst solvent-free

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Characteristics of Positive Ions in the Sheath Region of Magnetized Collisional Electronegative Discharges

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Plasma Science and Technology 2014年第6期16卷 552-556页

作者： M.M.HATAMI A.R.niknam Physics Department of K.N.Toosi University of Technology Laser-Plasma Research Institute of Shahid Beheshti University G.C.

A hydrodynamic model is used to investigate the characteristics of positive ions in the sheath region of a low-pressure magnetized electronegative discharge. Positive ions are modeled as a cold fluid, while the electron and negative ion density distributions obey the Boltzmann distribution with two different temperatures. By taking into account the ion-neutral collision effect in the sheath region and assuming that the momentum transfer cross section has a power law dependence on the velocity of positive ions, the sheath formation criterion （modified Bohm＇s criterion） is derived and it is shown that there are specified maximum and minimum limits for the ion Mach number M. Considering these two limits of M, the behaviors of electrostatic potential, charged particle density distributions and positive ion velocities in the sheath region are studied for different values of ion-neutral collision frequency.

关键词： electronegative plasma hydrodynamic model magnetized plasma sheath,Bohm's criterion

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Synthesis of some new bis-3,4-dihydropyrimidin-2(1H)-ones by using silica-supported tin chloride and titanium tetrachloride

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Chinese Chemical Letters 2010年第4期21卷 399-402页

作者： Khodabakhsh niknam Alireza Hasaninejad Madihe Arman Department of Chemistry Faculty of SciencesPersian Gulf University

Silica-supported tin chloride and titanium tetrachloride were prepared by the reaction of tin chloride and titanium tetrachloride with activated silica gel in refluxing *** solid acids have been employed as the catalysts for the synthesis of bisdihydropyrimidin -2(1H)-ones from aromatic dialdehydes,1,3-dicarbonyl compounds and urea at 90℃under solvent-free conditions.

关键词： Silica-supported tin chloride Silica-supported titanium tetrachloride Bis-3 4-dihydropyrimidin-2(1H)-one Solvent-free 1 3-Dicarbonyl compounds

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