检索结果-南通市图书馆

Open Journal of Geology 2024年第5期14卷 617-628页

作者： Hassan ibrahim Maharou karimou Laouali Idi Diafarou Alzouma Amadou Salissou Abdoul Ganiou Amadou Gnissa Sidibé Moussa konaté Department of Geology Faculty of Science and Techniques Abdou Moumouni University Niamey Niger Department of Life and Earth Sciences Ecole Normale Sup&#233rieure (ENS) Abdou Moumouni University Niamey Niger

This study focuses on exoscopic analyses of detrital zircon grains of Archean and Paleoproterozoic age, contained in the sediments from the Niamey Neoproterozoic sandstones (Niamey region), with a view to confirming the sediments sources already proposed (kénéma-Man domain for Archean-age zircons and Baoulé Mossi domain for Paleoproterozoic-age zircons). Exoscopic analysis reveals that Archean zircon grains are more corroded, with rounded to sub-rounded shapes, while Paleoproterozoic zircon grains are less corroded and mostly angular in shape. The strong corrosion of Archean zircon grains, implying long-distance transport, is consistent with the remoteness of the kenema-Man domain which are the source these sediments. The fact that the Paleoproterozoic zircon grains show little or no wear implies a proximal source of sediments, corresponding to the Baoulé Mossi domain.

关键词： Exoscopic Analysis Detrial Zircon Grains U-Pb Ages Niamey Neoproterozoic Sandstones Niamey Region

Synthesis of some new fused coumarin derivatives

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2000年第4期18卷 590-595页

作者： EL-DEEN ibrahim Mohey ibrahim H.k. MAHMOUD F.F. Faculty of Education Suez Canal University Port-Said EgyptFaculty of Science Suez Canal University Ismailia EgyptFaculty of Science (for Girls) Al-Azhar University Nasr City Egypt

2-Hydrazino-4-hydroxy-5H-[1]-benzopyrano-[4,3-d]-pyrimidin-5-one (3) was prepared via condensation of 2 with hydrazine hydrate. Treatment of 3 with methylene chloride, ethyl chloroformate, ethyl chloroacetate and benzaldehyde yielded the corresponding 2 - ( substituted ) hydrazino - 4 -hydro-xy-5H-[1]-benzopyrano-[4,3-d]-pyrimidin-5-one (4, 5, 6, and 10), followed by cyclization of 4, 5 and 6 with dimethyl formamide and fused sodium acetate under reflux, while compound 10 was cyclized with bromine and sodium acetate in acetic acid. Compound 3 reacted with β-(toloyl) acrylic acid, ethyl α-cyano-p-methoxycinnamate, diethyl malonate and acetyl chloride affording the corresponding 2-(substituted) hydrazino-4-hydroxy-5H-[1]-benzopyrano-[4,3-d]-pyrimidin-5-one (12, 13, 14, 15 and 16).

关键词： Synthesis fused coumarin derivatives cyclization

Numerical investigation on the heat transfer enhancement using a confined slot impinging jet with nanofluid

在线全文

学校读者我要写书评

暂无评论

Propulsion and Power Research 2019年第4期8卷 351-361页

作者： ibrahim k.Alabdaly M.A.Ahmed Department of Mechanical Engineering College of EngineeringUniversity of AnbarRamadiAnbarIraq

In this article,laminar convective heat transfer of a confined slot impinging jet with nanofluid has been numerically investigated over Reynolds number ranges of *** circular ribs are mounted on the lower-target surface:one rib located right the stagnation point and another one located on the left of the stagnation ***2-water nanofluid with nanoparticles volume fraction ranging from 0 to 4%and nanoparticles diameters of 30 nm has been *** two-dimensional governing continuity,momentum and energy equations have been solved using finite volume method based on SIMPLE *** effect of Reynolds number,nanoparticles volume fraction,rib height and rib location on the flow and thermal characteristics are presented and *** showed that the average Nusselt number,performance factor,total entropy generation as well as friction factor increase with increasing nanoparticles volume *** addition,it is found that the best thermal-hydraulic performance factor is around 1.89 which is obtained at Reynolds number of 1000,nanoparticles volume fraction of 4%,the rib height of 0.1 and the rib location of 2.

关键词： Jet impingement Nanofluid Entropy generation Thermal-hydraulic performance Finite volume method

Wear Behaviour of Plasma Paste Boronized of AISI 8620 Steel with Borax and B_2O_3 Paste Mixtures

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 Materials Science & Technology 2013年第7期29卷 662-668页

作者： ibrahim Gunes Department of Metallurgical and Materials Engineering Faculty of TechnologyAfyon Kocatepe UniversityAfyonkarahisar 03200Turkey

In the present study, AlSl 8620 steel was plasma paste boronized （PPB） by using paste mixtures with different borax and B2O3 percentages. The PPB process was carried out in a DC plasma system at 973, 1023 and 1073 k for 5 h in a gas mixture with 70% H2-30% Ar under a constant pressure of 103 Pa （10 mbar）. The thickness of boride layers ranged from 15.9 to 53.6 tim depending on the temperature and process time. The hardness of the borides formed on the surface of the steel substrate and unborided steel substrate were 1648-1924 HV0.05 and 226 HV0.05, respectively. X-ray diffraction analysis of the boride layers on the surface of the samples were obtained for FeB and Fe2B phases. The wear tests on the steel were performed by using a ball-on-disc test device at room temperature with applied load of 10 N and with a shear velocity of 0.2 m/s. Wear test results showed that the highest value of wear rate was observed in the unborided sample while the lowest wear rate was observed in the PPB samples with 30% borax ＋ 70% B4C paste at 1073 k for 5 h.

关键词： Coating Borax B2O3 Wear Coefficient of friction

Microstructure,Properties and Wear Behaviors of (Ni_3Al)_p Reinforced Cu Matrix Composites

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2011年第10期27卷 937-943页

作者： ibrahim elikyrek Nese .krpe Tugba ler Remzi Grler Metallurgical and Materials Engineering Department Faculty of Engineering and ArchitectureEski sehir Osmangazi University Institute of Metallurgy Eski sehir Osmangazi University

Pure copper and its composites reinforced with Ni3Al particles were produced by powder metallurgy （PM）. Ni3Al powders were produced by mechanical ball milling from vacuum arc melted compounds. The Ni3Al powders were characterized by X-ray diffraction （XRD）. The microscopy examinations revealed that the Ni3Al particles were distributed uniformly in the matrix. The effects of the particle fraction on the density, electrical conductivity, strength and dry sliding wear resistance of composite were investigated. It was found that the density and electrical conductivity of the composites decrease while the compression yield strength and wear resistance of composites increase with an increase in the particle fraction. The dry sliding wear tests were performed with pin-on-disk geometry. After sliding wear tests, the worn surfaces were examined by scanning electron microscopy （SEM） equipped with an energy dispersive X-ray spectrometer （EDS）. Results have shown that the wear mechanism is oxidative and adhesive.

关键词： Metal matrix composites Powder metallurgy Wear Intermetallics

Analytical Investigation of Soliton Solutions to Three Quantum Zakharov-kuznetsov Equations

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2018年第10期70卷 405-412页

作者： Rahmatullah ibrahim Nuruddeen khalid Suliman Aboodh khalid k. Ali Department of Mathematics Federal University Dutse Department of Mathematics Faculty of Science & Technology Omdurman Islamic University Department of Mathematics Faculty of Science & Arts University of Bisha Mathematics Department Faculty of Science Al-Azhar University

In the present paper, the two-dimensional quantum Zakharov-kuznetsov(QZk) equation, three-dimensional quantum Zakharov-kuznetsov equation and the three-dimensional modified quantum Zakharov-kuznetsov equation are analytically investigated for exact solutions using the modified extended tanh-expansion based method. A variety of new and important soliton solutions are obtained including the dark soliton solution, singular soliton solution, combined dark-singular soliton solution and many other trigonometric function solutions. The used method is implemented on the Mathematica software for the computations as well as the graphical illustrations.

关键词： two-dimensional QZk equation three-dimensional QZk equations soliton solutions

Binary Image Reconstruction Based on Prescribed Numerical Information

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2015年第2期31卷 519-528页

作者： k.G.Subramanian Pradeep Isawasan Rahmat Budiarto ibrahim Venkat School of Computer Sciences Universiti Sains Malaysia Networked Computing Center Surya University

The problem of reconstruction of a binary image in the field of discrete tomography is a classic instance of seeking solution applying mathematical techniques. Here two such binary image reconstruction problems are considered given some numerical information on the image. Algorithms are developed for solving these problems and correctness of the algorithms are discussed.

关键词： discrete tomography and binary image and reconstruction and subwords and Parikh matrix

kernel Granulometric Texture Analysis and Light RES-ASPP-UNET Classification for Covid-19 Detection

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2022年第4期71卷 651-666页

作者： A.Devipriya P.Prabu k.Venkatachalam Ahmed Zohair ibrahim Department of Computer Science and Engineering KPR Institute of Engineering and TechnologyCoimbatore641407India Department of Computer Science CHRIST(Deemed to be University)Bangalore560029India Department of Applied Cybernetics Faculty of ScienceUniversity of Hradec Králové50003Hradec KrálovéCzech Republic Computer Sciences Department College of Computer and Information SciencesPrincess Nourah Bint Abdulrahman UniversityRiyadhKSA.P.o.Box:84428Postal Code:11671

This research article proposes an automatic frame work for detectingCOVID -19 at the early stage using chest X-ray image. It is an undeniable factthat coronovirus is a serious disease but the early detection of the virus presentin human bodies can save lives. In recent times, there are so many research solutions that have been presented for early detection, but there is still a lack in needof right and even rich technology for its early detection. The proposed deeplearning model analysis the pixels of every image and adjudges the presence ofvirus. The classifier is designed in such a way so that, it automatically detectsthe virus present in lungs using chest image. This approach uses an imagetexture analysis technique called granulometric mathematical model. Selectedfeatures are heuristically processed for optimization using novel multi scaling deep learning called light weight residual–atrous spatial pyramid pooling(LightRES-ASPP-Unet) Unet model. The proposed deep LightRES-ASPPUnet technique has a higher level of contracting solution by extracting majorlevel of image features. Moreover, the corona virus has been detected usinghigh resolution output. In the framework, atrous spatial pyramid pooling(ASPP) method is employed at its bottom level for incorporating the deepmulti scale features in to the discriminative mode. The architectural workingstarts from the selecting the features from the image using granulometricmathematical model and the selected features are optimized using LightRESASPP-Unet. ASPP in the analysis of images has performed better than theexisting Unet model. The proposed algorithm has achieved 99.6% of accuracyin detecting the virus at its early stage.

关键词： Deep residual learning convolutional neural network COVID-19 X-ray principal component analysis granulo metrics texture analysis

Neoproterozoic U-Th-REE-bearing Pegmatites in Wadi Ibib, South Eastern Desert, Egypt: Structural and Geochemical Measures for a Syn-Tectonic Anatectic Model of Formation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2021年第6期95卷 2045-2062页

作者： Waleed S.ibrahim Nuclear Materials Authority El MaadiCairoEgypt

The Wadi Ibib area is situated in the northern part of the Neoproterozoic Hamisana Shear Zone(HSZ), which is a high strain zone evolved during the late stages of the Pan-African orogeny, likely as a tectonic escape structure. Amphibolite facies pelitic metasedimentary windows crop out in the axial parts of the HSZ and are noticeably associated with numerous N-trending pegmatite dikes. Whole-rock geochemistry of the pegmatites reveals a peraluminous(S-type) affinity, with low k/Rb ratios and elevated concentrations of U, Th, REE, Rb, Li, Cs, Y, Nb and Ta. Structurally, the pegmatite sets intrude along the shear plane of the HSZ, corresponding to the regional N-trending tectonic fabrics, such as axial planar foliation and dextral-shearing in the metasedimentary host rock. Field relationships, including structural context, coupled with geochemical characteristics of the Wadi Ibib pegmatites, do not support their formation as a complementary part of evolved granitic magmas. Space-localized decompression-induced partial melting of peraluminous garnet-bearing metapelites was alternatively the underlying process for formation of these pegmatites. Such decompression was associated with regional escape tectonics and stress axes permutations during the late deformation stage(D3) in the evolution of the south Eastern Desert terrane, due to end-orogeny system pressure-release.

关键词： U-Th-REE mineralization anataxis pegmatite origin Hamisana Shear Zone Wadi Ibib Egypt

Helicobacter pylori and other Helicobacter species DNA in human bile samples from patients with various hepato-biliary diseases

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2006年第14期12卷 2181-2186页

作者： Santosh k Tiwari Aleem A khan Mohd ibrahim Mohd Aejaz Habeeb C M Habibullah Center for Liver Research and Diagnostics Deccan College of Medical Sciences KanchanbaghHyderabad 500 058Andhra PradeshIndia Center for Liver Research and Diagnostics Deccan College of Medical Sciences KanchanbaghHyderabad 500 058Andhra PradeshIndia Department of GastroenterologyDeccan College of Medical Sciences Hyderabad 500 058Andhra PradeshIndia

AIM： To investigate the presence of Helicobacter species by nested PCR of 16S rRNA genes followed by the presence of Flelicobacter pylori （H pylori） 16S rRNA, ureA, cagA genes in bile obtained at endoscopic retrograde cholangio-pancreatography （ERCP） from 60 Indian subjects. METHODS： Sixty bile samples were obtained from patients diagnosed with various hepato-biliary diseases and control subjects at ERCP. PCR analysis was carried out using primers for Helicobacter genus 16S rRNA gene and H pylori （16S rRNA, urea and cagA） genes. Gastric H pylori status was also assessed from biopsies obtained at endoscopy from patients with various hepatobiliary diseases and controls. The control group mainly consisted of subjects with gastric disorders. Sequencing analysis was performed to confirm that PCR products with 16S rRNA and cagA primers were derived from H pylori. RESULTS No Helicobacters were grown in culture from the bile samples. Helicobacter DNA was detected in bile of 96.7% and 6.6% of groups Ⅰ and Ⅱ respectively. Ten from group Ⅰ were positive for 16S rRNA and ureA and 9 were positive for cagA gene. In contrast of the 2 from the control, 1 amplified with 16S rRNA, ureA and cagA primers used. The sequences of the 16S rRNA genes and cagA were 99% similar to Helicobacter pylori. CONCLUSION： Helicobacters are associated with the pathogenesis of various hepato-biliary disorders.

关键词： Helicobacter pylori Bile Hepato-biliary diseases PCR, Sequence analysis