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Study on Sesame Export for Sudan Based on Gravity Model

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World Journal of Engineering and Technology 2017年第2期5卷 31-39页

作者： mansour yousif ahmed adam Shiwei Xu Wen Yu Shengwei Wang Siek Darith Agricultural Information Institute Chinese Academy of Agricultural Sciences Beijing China Key Laboratory of Digital Agricultural Early-Warning Technology Ministry of Agriculture Beijing China

This study aimed to investigate the effect of social and economic differences between importer and exporter countries on trade flows of Sesame seed product. The analysis was carried out by estimating the gravity model. The sample covered a total of 14 countries for the period from 1997 to 2009. The results showed that the social and economic differences between countries have a significant and positive or negative effect on Sesame seeds trade. Furthermore, we found that the same language, distance and sesame production in export country have positive effect for the sesame export from Sudan.

关键词： Sesame Trade Gravity Model Sudan Partner Countries Policy

Fuel cell stack design and modelling with a double-stage boost converter coupled to a single-phase inverter

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Clean Energy 2024年第1期8卷 188-196页

作者： Basem E.Elnagi ahmed M.Ismaiel Hany S.E.mansour M.N.Abd-Alwahab Electrical Engineering Department Faculty of EngineeringSuez Canal UniversityIsmailia 41522Egypt

A comprehensive proton-exchange membrane fuel cell stack model was developed and integrated with a two-stage DC/DC boost *** was directly coupled to a single-phase(two levels-four pulses)inverter without a *** pulse-width modu-lation signal was used to independently regulate every converter *** converter was modelled using a MATLAB®/Simulink®environment and an appropriate voltage control *** analysis features of the suggested circuit were created and,through established experiments,the simulation results were verified.A single-phase(two levels-four pulses)inverter control circuit was tested and it produced a pure sinusoidal waveform with voltage *** matches the voltage of the network in terms of amplitude and frequency.A sinusoidal pulse-width modulation approach was performed using a single-phase(two levels-four pulses)pulse-width modulation *** results demonstrated an enhancement in the standard of the output wave and tuned the dead time with a reduction of 63μs compared with 180μs in conventional techniques.

关键词： PEM fuel cell pulse-width modulation single-phase inverter and double-stage DC/DC boost converter

Kaoline-based catalyst for a high stability desulfurization of sour heavy naphtha in a three-phase oscillatory baffled reactor

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Particuology 2024年第1期84卷 249-260页

作者： Hassan M.Hmood Saba A.Gheni Safaa M.R.ahmed Mudheher M.Ali Hamid Yonis Saleh Mohammed H.Mohammed Awad E.Mohammed Marwan A.Mahomood Hiba R.Mohammed ahmed A.Hassan adam Harvey North Refineries Company Ministry of OilIraq Chemical Engineering Department Tikrit UniversityIraq Ministry of Oil Iraq AL-Hawija Technical Institute Northern Technical UniversityMoselIraq School of Engineering Newcastle UniversityUK

To meet the rapidly increasing demand for energy and the dramatic depletion of conventional crude oil,it is imperative to utilize sour *** no coke being produced,oxidative desulfurization(ODS)of naphtha lowers its sulfur content and average molecular *** this article,we outline a method for heavy naphtha non-extractive ODS using a very stable *** technique involves the use of a solid catalyst with oxygen gas as the *** necessitated relatively high mixing intensities;hence a three-phase Oscillatory Baffled Reactor(OBR)was *** catalyst was based on the zeolite ZSM-5,prepared from natural kaolin by a series of delamination and activation steps and impregnated with Fe.A TiO2 nanolayer was applied,using the sol-gel method,to prevent rapid *** reactor performance was evaluated to minimize the sulfur content in the naphtha *** to the protective coating,the sulfur conversion stabilized at 90%.The results of this work establish the use of natural clay-based catalysts in a continuous,three-phase ODS,particularly with regard to proving long-term *** also showed that modest ODS can be achieved using an environmentally friendly oxidant,at mild operating conditions,whilst maintaining stability.

关键词： Natural kaoline Desulfurization Three-phase Oscillatory baffled reactor

川北—鄂西上二叠统富有机岩沉积与地球化学特征

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沉积学报 2024年第3期42卷 774-798,I0001页

作者：韦恒叶胡谍邱振张璇刘雯孔维亮 mansour ahmed 西南石油大学地球科学与技术学院成都610500 西南石油大学羌塘盆地研究院成都610500 中国石油天然气股份有限公司勘探开发研究院北京100083

【目的】随着非常规油气理论的发展,沉积有机质富集机理再次成为热点研究,其中有机质富集主控因素成为争论的焦点。以往的研究对沉积过程的分析较少,这可能是存在争论的原因之一。【方法】结合沉积学与地球化学研究方法,在分析层序地层... 详细信息

【目的】随着非常规油气理论的发展,沉积有机质富集机理再次成为热点研究,其中有机质富集主控因素成为争论的焦点。以往的研究对沉积过程的分析较少,这可能是存在争论的原因之一。【方法】结合沉积学与地球化学研究方法,在分析层序地层学和沉积环境的基础上,详细开展元素地球化学研究,讨论富有机岩沉积有机质富集机理。【结果】四川盆地北部和鄂西盆地上二叠统吴家坪组自下而上分为吴一段、吴二段和吴三段,大隆组自下而上分为大一段和大二段。吴家坪组至大隆组自下而上总共分为五个三级层序SQ1~SQ5。由层序地层学分析将广利海槽和鄂西海槽的发展分为四个阶段,分别为初始、快速发展、高潮稳定和萎缩阶段。初始阶段主要发育SQ2时期斜坡相暗色硅质灰岩,快速发展阶段主要发育SQ3时期陆棚相钙质页岩,高潮稳定阶段主要发育SQ4时期盆地相黑色硅质岩,萎缩阶段主要发育SQ5时期斜坡相石灰岩。含异常高有机质的甜点段主要形成于SQ3高位域至SQ5海侵域沉积期,在该时期Fe、Cu、Ni和Zn营养元素周期性富集,Mo、V、Fe/Al和S等氧化还原敏感元素均表现为较高的水平,热液强度参数Al/(Al+Fe+Mn)和Al-Fe-Mn三角图均指示频繁的热液活动特征。【结论】在甜点段,高营养元素含量和初级生产力水平的出现早于强还原条件,说明沉积水体的氧化还原条件主要受控于沉积有机质沉降埋藏过程中对氧的消耗,有机质的富集主要受较高初级生产力的控制。营养物质P、Si、Fe、Zn的供应主要与裂陷槽形成过程中深部热液活动和周围火山活动有关,这些构造活动周期性带来大量营养物质提高了初级生产力水平。因此海洋表层高的初级生产力水平是甜点段异常高有机质富集的启动和基础条件,而海洋底部水体较强的还原环境是有机质埋藏和保存的关键因素。

关键词：富有机岩甜点段吴家坪组大隆组层序地层元素地球化学四川盆地鄂西盆地

Consecutive narrow and broad quasi-periodic fast-propagating wave trains associated with a flare

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Science China(Physics,Mechanics & Astronomy) 2024年第5期67卷 200-211页

作者： Xinping Zhou Yuandeng Shen Chengrui Zhou Zehao Tang ahmed ahmed Ibrahim College of Physics and Electronic Engineering Sichuan Normal UniversityChengdu 610068China State Key Laboratory of Space Weather Chinese Academy of SciencesBeijing 100190China Yunnan Observatories Chinese Academy of SciencesKunming 650216China Department of Physics and Astronomy College of ScienceKing Saud UniversityP.O.Box 2455Riyadh 11451Saudi Arabia

The excitation mechanism of coronal quasi-period fast-propagating(QFP)wave trains remains *** Atmospheric Imaging Assembly onboard the Solar Dynamics Observatory observations,we study a narrow and a broad QFP wave trains excited one after another during the successive eruptions of filaments hosted within a fan-spine magnetic system on October 20,*** consecutive occurrence of these two types of QFP wave trains in the same event provides an excellent opportunity to explore their excitation mechanisms and compare their physical *** observational results reveal that narrow and broad QFP wave trains exhibit distinct speeds,periods,energy fluxes,and relative intensity amplitudes,although originating from the same active region and being associated with the same GOES C2.9 *** wavelet analysis,we find that the narrow QFP wave train shares a similar period with the flare itself,suggesting its possible excitation through the pulsed energy release in the magnetic reconnection process that generated the accompanying *** the other hand,the broad QFP wave train appears to be associated with the energy pulses released by the successive expansion and unwinding of filament ***,it is plausible that the broad QFP wave train was also excited by the sequential stretching of closed magnetic field lines driven by the erupting *** findings shed light on the different excitation mechanisms and origins of the QFP wave trains.

关键词： narrow wave excitation

Homologous heterostructure of MoS_(2) and MoO_(2) coupled with carbon layers as cathode catalyst for rechargeable lithium-oxygen batteries

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Rare Metals 2024年第7期43卷 3383-3390页

作者： Yi-Ming Zhang Zhao-Rui Zhou Lan-Ling Zhao Ye-Bing Li Rui-Feng Li Ya Zhou Sana Shoukat Abulgasim-ahmed-Abbaker adam Jun Wang Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials(Ministry of Education) Shandong UniversityJinan 250061China Shenzhen Research Institute of Shandong University Shenzhen 518063China School of Physics Shandong UniversityShenzhen 518063China

Lithium-oxygen batteries tend to experience high overpotentials because of the sluggish oxygen reduction reaction and oxygen evolution reaction during cycling.A potential solution to address this issue is to develop a... 详细信息

关键词： lithium process. kinetics

Study of scalar particles through the Klein–Gordon equation under rainbow gravity effects in Bonnor–Melvin-Lambda space-time

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Communications in Theoretical Physics 2024年第4期76卷 113-125页

作者： Faizuddin ahmed Abdelmalek Bouzenada Department of Physics University of Science&Technology MeghalayaRi-Bhoi793101India Laboratory of theoretical and applied Physics Echahid Cheikh Larbi Tebessi UniversityAlgeria

In our investigation,we explore the quantum dynamics of charge-free scalar particles through the Klein–Gordon equation within the framework of rainbow gravity,considering the Bonnor–Melvin-Lambda(BML)space-time *** BML solution is characterized by the magnetic field strength along the axis of the symmetry direction which is related to the cosmological constantΛand the topological parameterαof the *** behavior of charge-free scalar particles described by the Klein–Gordon equation is investigated,utilizing two sets of rainbow functions:(i)f(χ)=■,h(χ)=1 and(ii)f(χ)=1,h(χ)=1+βХ/*** 0<(Х=■)≤1 with E representing the particle's energy,Ep is the Planck's energy,andβis the rainbow *** obtain the approximate analytical solutions for the scalar particles and conduct a thorough analysis of the obtained ***,we study the quantum dynamics of quantum oscillator fields within this BML space-time,employing the Klein–Gordon *** also,we choose the same sets of rainbow functions and obtain the approximate eigenvalue solution for the oscillator ***,we demonstrate that the relativistic approximate energy profiles of charge-free scalar particles and oscillator fields get influenced by the topology of the geometry and the cosmological ***,we show that the energy profiles of scalar particles receive modifications from the rainbow parameter and the quantum oscillator fields by both the rainbow parameter and the frequency of oscillation.

关键词： quantum fields in curved space-time relativistic wave equations solutions of wave equations bound-state special functions

Application of Synthetic Iron Oxyhydroxide with Influencing Factors for Removal of As(Ⅴ) and As(Ⅲ) from Groundwater

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Journal of Earth Science 2024年第3期35卷 998-1009页

作者： Shakeel ahmed Talpur Muhammad Yousuf Jat Baloch Chunli Su Javed Iqbal Aziz ahmed Hafeez ahmed Talpur School of Environmental Studies China University of GeosciencesWuhan 430078China DiSPUTer Department of PsychologicalHealth and Territory SciencesUniversity“G.d′Annunzio”Chieti-Pescara66100 ChietiItaly College of New Energy and Environment Jilin UniversityChangchun 130021China School of Plant Environment and Soil SciencesLouisiana State University Agricultural CentreBaton Rouge LA 70803USA Department od Engineering and Geology University“G.d′Annunzio”Chieti-Pescara66100 ChietiItaly

Synthesized iron oxyhydroxide was applied for the adsorptive removal of As(V)and As(III)from the aquas ***,this investigation highlighted the synergistic effect of calcium carbonate in conjunction with iron oxyhydroxide,resulting in enhanced removal *** experiment was conducted under various conditions:concentration,dosage,pH,agitation,and *** characterizations such as Brunauer Emmett Teller,X-ray diffraction,scanning electron microscopy,and Fourier transform infrared spectroscopy were implied to understand adsorption *** Langmuir model revealed optimal concentrations for As(V)=500μg/L at pH-5 and As(III)=200μg/L at pH-7,resulting in 95%and 93%adsorption efficiencies,*** adsorption capacities“qm”were found to be 1266.943μg/g for As(V)and 1080.241μg/g for As(III).Freundlich model demonstrated favorable adsorption by indicating“n>1”such as As(V)=2.542 and As(III)=2.707;similarly,the speciation factor“RL<1”for both species as As(V)=0.1 and As(III)=0.5,*** kinetic study presented a pseudo-second-order model as best fitted,indicating throughout chemisorption processes for removing As(V)and As(III).Furthermore,incorporating calcium carbonate presented a significant leap in the removal efficiency,indicating As(V)from 95%to 98%and As(III)from 93%to 96%,*** findings offer profound motivation for developing effective and sustainable solutions to tackle arsenic contamination,underscoring the exceptional promise of iron oxyhydroxide in conjunction with calcium carbonate to achieve maximum removal efficiency.

关键词： adsorption arsenic As(V) As(III) iron oxyhydroxide isotherms kinetics groundwater.

Comparative efficacy of proximal femoral nail vs dynamic condylar screw in treating unstable intertrochanteric fractures

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World Journal of Orthopedics 2024年第8期15卷 796-806页

作者： ahmed Mohamed yousif Mohamed Monzir Salih Mohanad Abdulgadir Ayman E Abbas Duha Lutfi Turjuman Department of Orthopaedic Surgery Burjeel Medical CityAbu Dhabi 92510United Arab Emirates Department of General Surgery Burjeel Medical CityAbu Dhabi 92510United Arab Emirates Medical Intern Burjeel Medical CityAbu Dhabi 92510United Arab Emirates

BACKGROUND Among the most frequent hip fractures are trochanteric fractures,which usually occur from low-energy trauma like minor falls,especially in older people with osteoporotic *** To evaluate the treatment efficacy of dynamic condylar screws(DCS)and proximal femoral nails(PFN)for unstable intertrochanteric *** To find pertinent randomized controlled trials and retrospective observational studies comparing PFN with DCS for the management of unstable femoral intertrochanteric fractures,a thorough search was carried *** research studies published between January 1996 and April 2024,PubMed,EMBASE,Scopus,Web of Science,Cochrane Library,and Google Scholar were all *** complete texts of the papers were retrieved,vetted,and independently examined by two *** were settled by consensus,and any disagreements that persisted were arbitrated by a third *** This study included six articles,comprising a total of 173 *** to the DCS,the PFN had a shorter operation time[mean difference(MD):-41.7 min,95%confidence interval(95%CI):-63.04 to-20.35,P=0.0001],higher success rates with closed reduction techniques[risk ratio(RR):34.05,95%CI:11.12-104.31,P<0.00001],and required less intraoperative blood transfusion(MD:-1.4 units,95%CI:-1.80 to-1.00,P<0.00001).Additionally,the PFN showed shorter fracture union time(MD:-6.92 wk,95%CI:-10.27 to-3.57,P<0.0001)and a lower incidence of reoperation(RR:0.37,95%CI:0.17-0.82,P=0.01).However,there was no discernible variation regarding hospital stay,implant-related complications,and *** Compared to DCS,PFN offers shorter operative times,reduces the blood transfusions requirements,achieves higher closed reduction success,enables faster fracture healing,and lowers reoperation incidence.

关键词： Intertrochanteric fracture Unstable Dynamic condylar screw Proximal femoral nail Meta-analysis Comparative study