检索结果-南通市图书馆

Chinese Journal of Chemical Engineering 2022年第11期51卷 75-85页

作者： mohamed A.Almaradhi hassan m.A.hassan mosaed S.Alhumaimess Department of Chemistry College of ScienceJouf UniversityPO Box 2014SakakaSaudi Arabia

Suzuki-miyaura(S-m)is regarded the most powerful way for synthesis biaryls,triaryls,or incorporating of substituted aryl moieties in organic preparation by the cross-coupling of aryl boronic acid with aryl halides using the Pd *** work reports the combining of the hydrothermal and microwaveassisted protocol to convert the glucose to magnetic carbon spheres(Fe_(3)O_(4)-CSPs)decorated with Pd nanoparticles(NPs)as the catalyst for Suzuki-miyaura cross-coupling *** physicochemical properties in the produced composite were examined using FESEm,HRTEm,nitrogen isotherms,Raman spectroscopy,FTIR,XPS,and *** as-fabricated composite Pd/Fe_(3)O_(4)-CSPs is mostly spherical with a core–shell structure and possesses a great surface area of 253.2 m^(2).g^(-1).Its catalytic performance demonstrates that the composite has excellent stability and high tolerance Suzuki-miyaura crosscoupling reactions in 30 min at 80℃.Both activated and deactivated aryl halides provided excellent *** as-fabricated catalyst was recycled for up to four catalytic cycles without a substantial decline in ***,this research offers a facile roadmap for synthesizing Pd/Fe_(3)O_(4)-CSPs composites and promoting the practical implementation of Pd/Fe_(3)O_(4)-CSPs catalysts for organic transformation processes.

关键词： Heterogeneous catalysis Aryl halide Suzuki coupling Palladium nanoparticles Carbon spheres

Statistical Inference of Chen Distribution Based on Two Progressive Type-II Censoring Schemes

在线全文

学校读者我要写书评

暂无评论

Computers, materials & Continua 2021年第3期66卷 2797-2814页

作者： hassan m.Aljohani Department of mathematics&Statistics Faculty of ScienceTaif UniversityTaif21944Saudi Arabia

An inverse problemin practical scientific investigations is the process of computing unknown parameters from a set of observations where the observations are only recorded indirectly,such as monitoring and controlling quality in industrial process *** regression can be thought of as linear inverse *** other words,the procedure of unknown estimation parameters can be expressed as an inverse ***,maximum likelihood provides an unstable solution,and the problembecomes more complicated if unknown parameters are estimated from different ***,researchers search for better *** study two joint censoring schemes for lifetime products in industrial process *** practice,this type of data can be collected in fields such as the medical industry and industrial *** this study,statistical inference for the Chen lifetime products is considered and analyzed to estimate underlying *** likelihood and Bayes’rule are both studied for model *** asymptotic distribution of maximumlikelihood estimators and the empirical distributions obtained withmarkov chainmonte Carlo algorithms are utilized to build the interval *** results using tables and figures are adopted through simulation studies and verified in an analysis of the lifetime *** briefly describe the performance of developed methods.

关键词： Chen distributions progressive type-II censoring maximum likelihood mean posterior Bayesian estimation mCmC

Large magnetocaloric effect and magnetic properties of EuRhO3

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第9期42卷 1724-1729页

作者： m.Lassri m.Sajieddine A.Elouafi A.El Hachmi S.El Ouahbi R.moubah Laboratory of Energy and materials Engineering (LGEm) University of Sultan Moulay SlimaneFaculty of Science and Technology (FST) Institute of Applied Physics (IAP)-School of Industrial management (EmINES) Mohammed Ⅵ Polytechnic University National School of Applied Sciences (ENSA) University of Sultan Moulay Slimane Laboratory of mechanics Production and Industrial Engineering (LMPGI)Higher School of Technology of Casablanca (ESTC)University of Hassan Ⅱ Casablanca Laboratory of Radiation on matter and Instrumentation (LRmI) Faculty of Science and Technology (FST) SettatHassan Ⅰ University Laboatory of Physics of Advanced materials and Thermic (LPmAT) Faculty of Science Ain Chock (FSAC)University of Hassan Ⅱ Casablanca

We report on the structural,magnetic,and magnetocaloric properties of *** oxidation states of Eu and Rh ions were studied using X-ray photoelectron spectroscopy（XPS）.It is found that the Eu ions are mainly in the divalent oxidation state while the Rh ions have+4 ***3powders are found to be antiferromagnetic with a second order magnetic transition at Neel temperature（TN=2.9 K）.Analysis of the magnetic susceptibility versus temperature data in terms of the Curie=Weiss law:(χ=C/（T-θW）) for T>TN,yields θW=-3.1 K and effective magne tic moment ■,which is close to the theoretical value ■.The magnetic entropy change(-ΔSm),was determined by em ploying the thermodynam ic maxwell's *** μ0H=5 T and near TN,■ and relative cooling power（RCP） exhibit large values of 33.7 J/（kg·K） and 238 J/kg,*** large magnitude of-ΔSmand RCP show that the EuRhO3compound could be a potential candidate to be used in cryogenic magnetic refrigeration.

关键词： X-ray photoelectron spectroscopy Cryogenic magnetic refrigeration magnetic properties magnetocaloric effect Rare earths

InGaN/GaN laser diode characterization and quantum well number effect

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Optics Letters 2009年第3期7卷 226-230页

作者： S.m.Thahab H.Abu hassan Z.hassan Nano-Optoelectronics Research and Technology Laboratory School of PhysicsUniversiti Sains Malaysia

The effect of quantum well number on the quantum efficiency and temperature characteristics of In- GaN/GaN laser diodes （LDs） is determined and investigated. The 3-nm-thick In0.13Ca0.87N wells and two 6-am-thick GaN barriers are selected as an active region for Fabry-Perot （FP） cavity waveguide edge emitting LD. The internal quantum efficiency and internal optical loss coefficient are extracted through the simulation software for single, double, and triple InGaN/GaN quantum wells. The effects of device temperature on the laser threshold current, external differential quantum efficiency （DQE）, and output wavelength are also investigated. The external quantum efficiency and characteristic temperature are improved significantly when the quantum well number is two. It is indicated that the laser structures with many quantum wells will suffer from the inhomogeneity of the carrier density within the quantum well itself which affects the LD performance.

关键词： Computer software Efficiency Fabry Perot interferometers Quantum well lasers Semiconductor lasers Semiconductor quantum wells

Swimming of motile gyrotactic microorganisms and suspension of nanoparticles in a rheological Jeffery fluid with Newtonian heating along elastic surface

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2021年第11期28卷 3279-3296页

作者： Siddra RANA Rashid mEHmOOD m.m.BHATTI mohsan hassan Department of mathematics Faculty of Basic Sciences University ofWahWah CanttPakistan Department of mathematics Faculty of Natural SciencesHITEC UniversityTaxila CanttPakistan College of mathematics and Systems Science Shandong University of Science and TechnologyQingdao 266590China Department of mathematics Comsats University IslamabadLahore CampusPakistan

Bioconvection plays an inevitable role in introducing sustainable and environment-friendly fuel cell ***-mathematical modelling of such designs needs continuous refinements to achieve strong agreements in experimental and computational ***,microorganisms transport a miscellaneous palette of ingredients in manufacturing industrial goods particularly in fertilizer *** transfer characteristics of molecular structure are measured by a physical phenomenon which is allied with the transpiration of heat within *** by bioinspired fuel cells involved in near-surface flow phenomena,in the present article,we examine the transverse swimming of motile gyrotactic microorganisms numerically in a rheological Jeffery fluid near a stretching *** leading physical model is converted in a nonlinear system of ODEs through proper similarity alterations.A numerical technique called shooting method with R-K Fehlberg is applied via mathematical software and graphical presentations are *** influence of all relative physical constraints on velocity,temperature,concentration,and volume fraction of gyrotactic microorganisms is expressed *** is found that heat and mass flux at the surface as well as density of motile microorganism’s declines for Brownian motion and thermophoresis *** in tabular form is made with existing literature to validate the results for limiting cases with convective boundary conditions.

关键词： oblique stagnation point flow Jeffery fluid bioconvection swimming of motile gyrotactic nanoparticles

Theoretical investigation of optical properties and band gap engineering for Zn1-xTmxTe(Tm=Fe,Co)alloys by modified Becke-Johnson potential

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2017年第8期26卷 491-498页

作者： Q mahmood m Yaseen m hassan Shahid m Ramay Asif mahmood materials Growth and Simulation Laboratory Department of PhysicsUniversity of the PunjabQuaid-i-Azam Campus54590LahorePakistan Department Of Physlcs University of Agriculture UniversityFaisalabad 38040Pakistan Physics and Astronomy Department College of ScienceKing Sand UniversityRiyadhSaudi Arabia Chemical Engineering Department College of EngineeringKing Saud UniversityRiyadhSaudi Arabia

The direct band gap ZnTe with transition metal （Tm） impurities plays a vital role in optoelectronic and spintronic applications. In the present study, we use the advanced modified Becke-Johnson （mBJ） functional for performing the structural computations and detailed investigations of the optical characters in Zn1_xTmxTe （Tm = Fe, Co） alloys with 0 ≤ x ≤1. By employing the FP-LAPW method, we determine various optical parameters for the ternary alloys and for the end binaries. The calculated static dielectric constants and optical band gaps for Zn1_xTmxTe （Tm = Fe, Co） have an inverse relation that verifies the Penn model. We find that the static dielectric constant is nearly equal to the square of the static refractive index, and both increase with Tm content. Furthermore, we also find a slight shift of peaks to a higher energy region with increasing Tm concentration. The decreasing band gap and high value of the absorption in the visible region of electromagnetic spectrum make these alloys suitable for photonic and solar cell applications.

关键词： amorphous semiconductors transition metal-doped ZnTe structural computation optical property

On Noncommutative Sinh-Gordon Equation

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2005年第5期22卷 1076-1078页

作者： U.Saleem m.Siddiq m.hassan DepartmentofPhysics UniversityofthePunjabQuaid-e-AzamCampusLahore-54590Pakistan

We give a noncommutative extension of a sinh-Gordon equation. We generalize a linear system and Lax representation of the sinh-Gordon equation in noncommutative space. This generalization gives a noncommutative versio... 详细信息

关键词： currents Linear system Generalization gordon's formula water currents

精索内静脉-腹壁下静脉双flow-through超引流技术治疗精索静脉曲张应用解剖

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

中华实验外科杂志 2024年第4期41卷 840-842页

作者： S m mahamudul hassan Rizvi 王莉沙米·艾合买提柳辉陈熹张之涵汪迎晖陶圣祥武汉大学中南医院创伤与显微骨科武汉430062 武汉市第六医院综合科武汉430014 武汉大学中南医院综合超声医学科武汉430062

目的观察成人腹壁下血管穿过腹股沟区域时的直径、血流速度、血管位置、血管长度,为精索静脉曲张双flow-through超引流技术提供解剖依据。方法2023年7月至2023年11月在武汉大学中南医院对30例年龄在20~30岁之间的成年男性进行B超检查,... 详细信息

目的观察成人腹壁下血管穿过腹股沟区域时的直径、血流速度、血管位置、血管长度,为精索静脉曲张双flow-through超引流技术提供解剖依据。方法2023年7月至2023年11月在武汉大学中南医院对30例年龄在20~30岁之间的成年男性进行B超检查,测量腹壁下静脉,腹壁浅静脉直径、血流速度,计量资料以均数±标准差(±s)表示,并进行文献查阅,查出腹壁下血管在腹股沟区域的走行及精索静脉曲张时的静脉管径及流速。并且在两具人体标本上进行精索内静脉-腹壁下静脉双flow-through超引流模拟手术,总结经验,得出较好的手术方法。组间比较采用t检验。结果通过B超测得的腹壁下动脉直径[(2.3±0.2)mm]大于腹壁浅动脉[(1.4±0.2)mm,t=10.312,Pmm]大于腹壁浅静脉直径[(1.3±0.2)mm,t=5.533,Pm/s]小于腹壁浅动脉流速[(4.33±0.61)cm/s,t=-1.505,P>0.05],腹壁下静脉流速[(1.77±0.23)cm/s]小于腹壁浅静脉流速[(3.03±0.58)cm/s,t=-6.017,P<0.01]。结论精索静脉曲张腹壁下静脉双flow-through超引流技术临床应用价值较高。

关键词：精索静脉曲张静脉分流术显微外科腹股沟血管

Synthesis of ZnO Nanoparticles onto Sepiolite Needles and Determination of Their Sensitivity toward Humidity, NO_2 and H_2

在线全文

学校读者我要写书评

暂无评论

Journal of materials Science & Technology 2016年第6期32卷 573-582页

作者： m.hassan Ahmed S.Afify J.m.Tulliani Department of Applied Science and Technology Politecnico di Torino

This work investigated the sensitivity toward humidity, NO2 and H2 of ZnO modified sepiolite （Si12mg8O30（OH）4.（H2O）4.8H2O）. To this aim, sepiolite powder was first modified by leaching magnesium ions in HCI then by precipitating nano-sized Zn-based compounds under basic conditions. A subse- quent thermal treatment at 550 ℃ for 1 h was performed. The powders were characterized by X-ray diffraction （XRD）, specific surface area measurements, thermogravimetric and differential thermal anal- ysis and field emission scanning electron microscopy, as well as high resolution transmission electron microscopy. The XRD patterns showed that all leached heat treated samples were made of anhydrous sepiolite and of ZnO. Sensors were then obtained by screen printing these materials onto commercial alumina substrates with Pt electrodes. All the investigated compositions were capable of detecting NO2 down to ppm level and 20 ppm H2, at an optimal working temperature of 300°C. These detection limits are in line with the current best results reported in literature.

关键词： Clay minerals Gas sensor Sensitivity Hydrogen sensor Nitrogen Oxide

Towards superior permeability and antifouling performance of sulfonated polyethersulfone ultrafiltration membranes modified with sulfopropyl methacrylate functionalized SBA-15

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2023年第1期53卷 89-100页

作者： Eid H.Alosaimi Ibrahim Hotan Alsohaimi hassan m.A.hassan Qiao Chen Saad melhi Ayman Abdelaziz Younes Department of Chemistry College of ScienceUniversity of BishaBisha 61922Saudi Arabia Chemistry Department College of ScienceJouf UniversitySakaka 2014Saudi Arabia Chemistry Department School of Life SciencesSussex UniversityBrighton BN19QJUK

A non-solvent induced phase separation(NIPS)process was used to fabricate a series of sulfonated polyethersulfone(SPES)membranes blending with different concentrations of SBA-15-g-PSPA with the applications in the ultrafiltration(UF)***-15 was modified with 3-methacrylate-propyltrime thoxysilane(mPS)to form *** was further modified with the charge tailorable polymer chains by reacting with 3-sulfopropyl methacrylate potassium *** nanoparticles were uniformly dispersed and finger-like channels were developed within the *** adding of surface modified SBA-15-g-PSPA nanoparticles has significantly improved membrane water permeability,hydrophilicity,and antifouling *** pure water fluxes of the composite SPES membranes were significantly higher than the pristine SPES *** the membrane containing 5%(mass)of SBA-15-g-PSPA(mSSPA5),the pure water flux was increased dramatically to 402.15 Lm^(-2)·h^(-1),which is ~1.5 times that of mSSPA0(268.0 Lm^(-2)·h^(-1)).The high flux rate was achieved with 3%(mass)of SBA-15 nanoparticles with retained high rejection ratio 98%for natural organic *** results indicate that the fashioned composite membrane comprising SBA-15-g-PSPA nanoparticles have a promising future in ultrafiltration applications.

关键词： Ultrafiltration membrane Antifouling Permeability SBA-15 NOm foulant