检索结果-南通市图书馆

Compositional Variation and Mineral Chemistry of the Jinshajiang and Lancangjiang Serpentinites, Yunnan Province, SW China

引用

Acta Geologica Sinica(english edition) 2014年第6期88卷 1705-1728页

作者： ahmed e.I.MASOUD YANG Jingsui LIU Fei State Key Laboratory of Continental Tectonics and Dynamics Institute of Geology Chinese Academy of Geological Sciences Faculty of earth Sciences China University of Geosciences Geology Department Faculty of Science Tanta University

We present the whole rock and the mineral chemical data for upper mantle peridotites from the San-Jiang region in Yunnan, SW China. These peridotites are a part of a Paleo-Tethyan ophiolite belt occurring along the Jinshajiang and Lancangjiang suture zones. All samples of the Jinshajiang and Lancangjiang ultramafic rocks are completely serpentinized. The Jinshajiang serpentinites are characterized by no relict of olivine and pyroxene, and the Cr# content of spinels is 0.32–0.49. The Lancangjiang serpentinites were collected from two different locations; the northern location which has some relict of Opx（Al2O3 is 0.13–2.2 wt%, TiO 2 is 0.004–0.057 wt% and Mg# content is 0.895–0.933） and the Cr# content of spinel is 0.26-0.55; the southern location, which has some relict of Olivine（Fo = 90–92.5 and NiO = 0.12–0.26 wt%）, and spinel Cr# ranging from 0.41 to 0.57. The whole rock geochemical and the mineral chemistry data imply that the Jinshajiang and Lancangjiang serpentinites represent abyssal peridotites residues after ~15–20% partial melting for the Jinshajiang and Lancangjiang serpentinites（south location）, and ~11–19% partial melting for the Lancangjiang serpentinites（north location）. In addition, the compositional trends of the spinel analyses of the Lancangjiang serpentinites imply that the MORB melt-peridotite interaction process played a significant role during their evolution. These processes are evidenced by an increase in Cr# with an increase in TiO 2, whereas the spinel analyses of the Jinshajiang serpentinites display an increase in Cr# with a decrease in Ti O2, indicating that the Jinshajiang serpentinites were subjected to a simple partial melting process.

关键词： chromite Jinshajiang ophiolite Lancangjiang ophiolite

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Developed mathematical technique for fractional stochastic point kinetics model in nuclear reactor dynamics

引用

Nuclear Science and Techniques 2018年第9期29卷 197-213页

作者： ahmed e.Aboanber Abdallah A.Nahla Adel M.edress Department of Mathematics Faculty of Science Taibah University Department of Mathematics Faculty of Science Tanta University

Fractional stochastic kinetics equations have proven to be valuable tools for the point reactor kinetics model, where the nuclear reactions are not fully described by deterministic relations. A fractional stochastic model for the point kinetics system with multi-group of precursors,including the effect of temperature feedback, has been developed and analyzed. A major mathematical and inflexible scheme to the point kinetics model is obtained by merging the fractional and stochastic technique. A novel split-step method including mathematical tools of the Laplace transforms, Mittage–Leffler function, eigenvalues of the coefficient matrix, and its corresponding eigenvectors have been used for the fractional stochastic matrix differential equation. The validity of the proposed technique has been demonstrated via calculations of the mean and standard deviation of neutrons and precursor populations for various reactivities: step, ramp, sinusoidal, and temperature reactivity feedback. The results of the proposed method agree well with the conventional one of the deterministic point kinetics equations.

关键词： Ito stochastic point kinetics equations Temperature feedback effects Wiener process Fractional calculus Mittage–Leffler function

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

effect of Pd or Ir on the catalytic performance of Mo/H-ZSM-5 during the non-oxidative conversion of natural gas to petrochemicals

引用

Journal of Natural Gas Chemistry 2008年第4期17卷 337-343页

作者： ahmed K.Aboul-Gheit ahmed e.Awadallah Salah M.el-Kossy Abdel-Lateef H.Mahmoud Process Development Division Egyptian Petroleum Research Institute Faculty of Science Department of ChemistryMNF University Ageeba Petroleum Co.

Natural gas conversion to petrochemicals, principally, benzene, naphthalene, toluene, as well as ethylene under non-oxidative conditions was examined in a fixed bed flow reactor at 700 ℃ and gaseous hourly space velocity （GHSV） of 1500 ml·g ^-1·h^-1 at time-on-stream ranging from 5 rain to 4 h using catalysts containing 6.0%Mo/H-ZSM-5 promoted with Pd or Ir metal. The catalysts were characterized by XRD, TPD, and TGA. The addition of Pd or Ir to 6%Mo/H-ZSM-5 catalyst promoted ethylene production but inhibited the cyclization reaction to aromatics owing to the strong interaction between these noble metals and the framework Al species, which were attached to the acid sites during the impregnation process. Coke deposition on the catalysts was found to decrease upon addition of 0.5wt% of Pd or Ir to 6%Mo/H-ZSM-5 catalyst owing to the hydrogenating activity of these metals.

关键词： natural gas methane benzene ethylene molybdenum Pd Ir H-ZSM-5

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

On the Generalized Thermoelasticity Problem for an Infinite Fibre-Reinforced Thick Plate under Initial Stress

引用

Advances in Applied Mathematics and Mechanics 2014年第6期6卷 783-796页

作者： ahmed e.Abouelregal Ashraf M.Zenkour Department of Mathematics Faculty of ScienceMansoura UniversityMansoura 35516Egypt Department of Mathematics Faculty of ScienceKing Abdulaziz UniversityP.O.Box 80203Jeddah 21589Saudi Arabia Department of Mathematics College of Science and ArtsUniversity of AljoufEl-QurayatSaudi Arabia Department of Mathematics Faculty of ScienceKafrelsheikh UniversityKafr El-Sheikh 33516Egypt

In this paper,the generalized thermoelasticity problem for an infinite fiberreinforced transversely-isotropic thick plate subjected to initial stress is *** lower surface of the plate rests on a rigid foundation and temperature while the upper surface is thermally insulated with prescribed surface *** normal mode analysis is used to obtain the analytical expressions for the displacements,stresses and temperature *** problem has been solved analytically using the generalized thermoelasticity theory of *** of phase-lags,reinforcement and initial stress on the field quantities is shown *** results due to the coupled thermoelasticity theory,Lord and Shulman’s theory,and Green and Naghdi’s theory have been derived as limiting *** graphs illustrated that the initial stress,the reinforcement and phase-lags have great effects on the distributions of the field quantities.

关键词： Dual-phase-lag theory fiber-reinforced initial stress normal mode analysis thick plate.

来源：

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

Tungsten ion source under double-pulse laser ablation system

引用

Chinese Physics B 2017年第9期26卷 285-296页

作者： ahmed Asaad I Khalil Ashraf I Hafez Mahmoud e elgohary Mohamed A Morsy Department of Laser Sciences and Interactions National Institute of Laser Enhanced SciencesCairo UniversityGiza 12613Egypt Central Laboratory of Ministry of electricity CairoEgypt Atomic Research Center Atomic Energy AuthorityCairo 13759Egypt Department of Nuclear engineering Jordan University of Science and Technology IrbidJordan Department of Chemistry King Fahd University of Petroleum and MineralsDhahran 31261Saudi Arabia

New tungsten ion source is produced by using single and double-pulse laser ablation system. Combined collinear Nd：YAG laser beams（266＋1064 nm） are optimized to focus on the sample in air. Optimization of the experimental parameters is achieved to enhance the signal-to-noise ratio of the emission spectra. The velocity distribution of the emitted plasma cloud is carefully measured. The influences of the potential difference between the bias electrodes, laser wavelength and intensity on the current signal are also studied. The results show that the increase in the tungsten ion velocity under the double-pulse lasers causes the output current signal to increase by about three folds. The electron density and temperature are calculated by using the Stark-broadened line profile of tungsten line and Boltzmann plot method of the upper energy levels, respectively. The signal intensity dependence of the tungsten ion angular distribution is also analyzed. The results indicate that the double-pulse laser ablation configuration is more potent technique for producing more metal ion source deposition, thin film formation, and activated plasma-facing component material.

关键词： tungsten ion beam double-pulse lasers ablation system laser ablation system optical Instrumentation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

High-fidelity optical diffraction tomography of multiple scattering samples

引用

Light(Science & Applications) 2019年第1期8卷 454-465页

作者： Joowon Lim ahmed B.Ayoub elizabeth e.Antoine Demetri Psaltis ecole Polytechnique Federale de Lausanne Optics LaboratoryCH-1015 LausanneSwitzerland

We propose an iterative reconstruction scheme for optical diffraction tomography that exploits the split-step nonparaxial(SSNP)method as the forward model in a learning tomography *** with the beam propagation method(BPM)previously used in learning tomography(LT-BPM),the improved accuracy of SSNP maximizes the information retrieved from measurements,relying less on prior assumptions about the sample.A rigorous evaluation of learning tomography based on SSNP(LT-SSNP)using both synthetic and experimental measurements confirms its superior performance compared with that of the *** from the accuracy of SSNP,LT-SSNP can clearly resolve structures that are highly distorted in the LT-BPM.A serious limitation for quantifying the reconstruction accuracy for biological samples is that the ground truth is *** overcome this limitation,we describe a novel method that allows us to compare the performances of different reconstruction schemes by using the discrete dipole approximation to generate synthetic ***,we explore the capacity of learning approaches to enable data compression by reducing the number of scanning angles,which is of particular interest in minimizing the measurement time.

关键词： scattering optical diffraction

来源：

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

enhancing asphaltene precipitation modeling by cubic-PR solid model using thermodynamic correlations and averaging techniques

引用

Petroleum Science 2020年第1期17卷 232-241页

作者： Aktham e.Shoukry ahmed H.el-Banbi Helmy Sayyouh Petroleum engineering University of WyomingLaramieWYUSA Petroleum Department Faculty of EngineeringCairo UniversityGizaEgypt Petroleum engineering American University in Cairo(AUC)GizaEgypt

Cubic equation-of-state solid models are one of the most widely used models to predict asphaltene precipitation *** parameters are needed to model precipitation under different pressures and temperatures and are usually obtained through tuning with multi asphaltene onset *** the purpose of enhancing the cubic Peng–Robinson solid model and reducing its dependency on asphaltene experiments,this paper tests the use of aromatics and waxes correlations to obtain these thermodynamic *** addition,weighted averages between both correlations are *** averaging is based on reported saturates,aromatics,resins,asphaltene(SARA)fractions,and wax *** the methods are tested on four oil samples,with previously published data,covering precipitation and onset *** proposed wax-asphaltene average showed the best match with experimental data,followed by a SARA-weighted *** new addition enhances the model predictability and agrees with the general molecular structure of asphaltene molecules.

关键词： Asphaltene precipitation Asphaltene onset pressure Asphaltene precipitation modeling Asphaltene thermodynamics Cubic equation of state

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Prediction of tensile strength of friction stir welded 6061 Al plates

引用

China Welding 2019年第3期28卷 1-6页

作者： Farghaly ahmed A el-Nikhaily ahmed e essa A R S Mechanical Department Faculty of Industrial EducationSuez University43527Egypt Mechanical engineering Department Egyptian Academy for Engineering&Advanced TechnologyAffiliated to Ministry of Military Production3056Egypt

The present paper investigates the prediction of tensile strength after friction stir welding(FSW)using artificial neural network(ANN)in the MATLAB *** experimental results are used to develop the mathematical *** combined influence of welding speed,rotation speed,and axial force on the tensile strength of 6061 Al plates is *** of the tensile test are used to train and test the ANN model.A multi-layer solution is developed using the ANN model to predict tensile *** propagation(BP)method is initially trained using 80%of the experimental data,then,testing is performed with the rest of the *** indicate that predicted values are close to the corresponding measured values.

关键词： prediction friction stir welding 6061 aluminum alloy artificial neural network model

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Ion-acoustic waves at the night side of Titan's ionosphere:higher-order approximation

引用

Communications in Theoretical Physics 2020年第5期72卷 70-77页

作者： S M ahmed e R Hassib U M Abdelsalam R e Tolba W M Moslem Department of Mathematics Faculty of ScienceSuez UniversitySuezEgypt Department of Mathematics Faculty of ScienceFayoum UniversityFayoumEgypt Department of Mathematics Rustaq College of EducationOman Centre for Theoretical Physics The British University in Egypt(BUE)El-Shorouk CityCairoEgypt Department of Physics Faculty of SciencePort Said UniversityPort Said 42521Egypt

Nonlinear solitary waves are investigated for a plasma system at the night side of Titan's *** plasma model consists of three positive ions,namely C2H5^+,HCNH^+,and C3H5^+,as well as Maxwellian *** basic set of fluid equations is reduced to a Korteweg de-Vries(KdV)equation and linear inhomogeneous higher order KdV(LIHO-KdV)*** solitary wave solutions of both equations are obtained using a renormalization *** solitary waves'existence region and the wave profile are investigated,and their dependences on the plasma parameters at the night side of Titan's ionosphere are *** solitary waves'phase velocities are subsonic or supersonic,and the propagating pulses are usually *** effect of higher-order corrections on the perturbation theory is *** is found that the higher-order contribution makes the amplitude slightly taller,which is suitable for describing the solitary waves when the amplitude augments.

关键词： plasmas ion-acoustic waves planets and satellites:atmospheres

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

efficacy and Safety of Ombitasvir plus Paritaprevir,Ritonavir and Ribavirin in Non-cirrhotic Treatment-naive and Treatment-experienced egyptians with Chronic HCV Genotype-4 Infection

引用

Current Medical Science 2021年第3期41卷 581-586页

作者： Manar ahmed Azza e.Mansey engy A.Wahsh ahmed A.Gomaa Hoda M.Rabea Department of Clinical Pharmacy Faculty of PharmacyBeni Suef UniversityBeni Suef 62521Egypt Department of Clinical Pharmacy Faculty of PharmacyMenoufia UniversityAl Menoufia 32511Egypt Department of Clinical Pharmacy Faculty of PharmacyOctober 6 universityGiza 12573Egypt Department of Tropical Medicine Faculty of MedicineFayoum UniversityFayoum 63511Egypt

Hepatitis C virus genotype 4(HCV-GT4)is a risk factor for cirrhosis,hepatocellular carcinoma and liver failure.A combination of three new direct-acting antivirals ombitasvir,paritaprevir,and ritonavir has been recommended for treatment of HCV-GT4 *** current study was aimed to assess the efficacy and safety of this combination plus ribavirin in non-cirrhotic,treatment-naive and-experienced egyptians with HCV-GT4 infection in a real-world setting.A total of 255 egyptians with HCV-GT4 infection were enrolled,including 82 treatment-experienced and 173 treatment-naive *** of them completed 12-week treatment protocol of ombitasvir,paritaprevir and ritonavir as an oral dose combination with *** response(VR)was measured,as well as the biochemical parameters related to treatment efficacy and adverse events at baseline and after treatment,at 4(VR4)and 12(VR12)weeks *** results showed that the VR4 rates were 98.8%in both groups,and VR12 rates were 97.7%and 96.3%in treatment-naive and-experienced patients,respectively,with no significant differences found between the groups concerning VR4(P=0.9)and VR 12(P=0.3).The most common adverse events were headache and fatigue,which were significantly more common(P=0.001 and 0.003,respectively)in treatment-experienced than in treatment-naive *** quadruple regimen was well-tolerated,and the reported adverse events were generally mild to *** real-world setting study confirms that the combination of ombitasvir,paritaprevir,ritonavir,and ribavirin is highly effective in the treatment of HCV-GT4 infection with a good safety and tolerability profile.

关键词： hepatitis C virus genotype-4 ombitasvir paritaprevir ribavirin

来源：

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

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：