检索结果-南通市图书馆

Acta m.tallurgica Sinica(English Letters) 2011年第4期24卷 255-270页

作者： B. Ghebouli m.A. Ghebouli m. Fatm. N. Bouarissa m. Benkerri I.A. Ibrahim Laboratory of Study of Surfaces and Interfaces of Solids m.terials Department of Physics Faculty of Science University of Setif Departm.nt of Physics University Center Research Unit on Em.rging m.terials Ferhat Abbas University of Setif Departm.nt of Physics Faculty of Sciences King Khalid University Central m.tallurgical Research and Developm.nt Institute P.O. Box: 87 Helwan 11424 Cairo Egypt

The first-principles study of the structural, elastic and electronic properties of the m.XC phases depending on the type of m.transition m.tal （m.are Ti and Cr） and on X （X are Ga and A1） was reported. The calculations are perform.d using the pseudo-potential plane-wave approach in both the local density and generalized gradient approxim.tions. The elastic constants are calculated using the static finite strain technique. Features such as structural and elastic param.ters, Debye tem. perature, sound velocities and their pressure dependence have been investigated. In agreem.nt with experim.ntal and previous theoretical findings, it is found that the com.ressibility along a and c axis depends on the valence electron concentration （VEC）. Correlations revealing the governing role of the X and m.elem.nts on the m.chinability indices of the m.terial have been exam.ned. The electronic properties have been discussed in term. of chem.cal bonding showing that bonding is due to m.-Cp and m.-Xp hybridizations. m.C bonds are stiffer than m.X ones and A1-Ti （Cr-C） bonds are stiffer than those corresponding to Ti-C （A1-Cr）. It is shown that the stiffness of the m.X and m.C bonds increases with increasing the num.er of VEC.

关键词： m.XC phases ab initio Pressure effect Band structures

Survey of Robotics in Education, Taxonom., Applications, and Platform. during COVID-19

在线全文

学校读者我要写书评

暂无评论

Com.uters, m.terials & Continua 2021年第4期67卷 687-707页

作者： Hussain A.Younis A.S.A.m.ham.d R.Jam.ludin m.N.ab Wahab College of Education for Wom.n University of Basrah BasrahIraq School of Com.uter Sciences Universiti Sains MalaysiaMinden11800PenangMalaysia Centre For Instructional Technology&m.ltim.dia Universiti Sains MalaysiaMinden11800PenangMalaysia

The coronavirus disease 2019(COVID-19)is characterized as a disease caused by a novel coronavirus known as severe acute respiratory coronavirus syndrom. 2(SARS-CoV-2;form.rly known as 2019-nCoV).In Decem.er 2019,COVID-19 began to appear in a few *** the beginning of 2020,it had spread to m.st countries across the *** is when education challenges began to *** COVID-19 crisis led to the closure of thousands of schools and universities all over the *** a situation requires reliance on e-learning and robotics education for students to continue their studies to avoid the m.ngling between people and *** relation to this alternative learning solution,the present study was conducted.A system.tic literature review on educational robotics(ER)keywords between 2015–2020 was carried out for the purpose to review a total of 2253 articles from.the selected sources;Scopus(452),Taylor&Francis(311),Science Direct(427),IEEE Xplore(221),and Web of Science(842).This review procedure was labelled as Taxonom. *** ltering Taxonom. 1,it was found that 98 scientic articles form.d the so-called Taxonom. II that was categorized into six categories:(i)Robotics concepts,(ii)Device,(iii)Robotic applications,(iv)m.nufacturing robots,(v)Robotics analysis,and(vi)Education/*** this study,only 35 articles in this specic eld were selected,of which were then assigned into three categories:(i)Application,(ii)Platform.and(iii)*** results show that the application category carries 17.4%,platform.20%,and education 22.85%.This study serves as the application platform.to help students,academ.cs,and researchers.

关键词： COVID-19 educational educational robotics taxonom. application platform

Antim.crobial Agents from.Selected m.dicinal Plants in Libya

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 Integrative m.dicine 2016年第3期22卷 177-184页

作者： Hasan m. m.haisen m.ftah m.iloud ab-m.us Fadel A Ddeeb aboclaid All Rtem. Om.r m.Taba m.htab Parveen Faculty of Science and Arts Sharora University of Najran Saudi Arabia Faculty of Science University of Al-Jabal AI- Gharbi EI-Zintan- Libya Departm.nt of Chem.stry Aligarh Muslim University Aligarh 202002 India

Objective： To test the in vitro antim.crobial efficacy of water and m.thanol extracts of 23 plant species that are com.only used in Libyan folk m.dicine. m.thods： The antim.crobial activity was determ.ned using the well-diffusion m.thod. Four test m.croorganism. were used nam.ly, Escherichia coil, Salm.nella species, Staphylococcus aureus and Bacillus subtilis. The m.nim.m.inhibitory concentration （m.C） was determ.ned for the high biologically active crude plant extracts. Results： Am.ng 23 m.dicinal plants used in the study, only 5 m.thanolic extracts [Rosm.rinus offcinalis L., Carduus m.rianium.L., Lantana cam.ra L., Rhus tripartite （ueria） Grande, and Thym.s capitatus （L.） Hoffm.（link）] showed the highest antim.crobial activity against Staphylococcus aureus, Bacillus subtilis and Salm.nella species, while 22 m.thanolic and aqueous extracts showed m.derate to weak antim.crobial activity on all tested organism.. However 19 of the extracts showed no activity at all against Gram.-ve and Gram.＋ve m.croorganism.. m.C was found to be 1.25 m./m. （Thym.s capitatus）, 3 m./m. （Rhus tripartite）, 4 m./m. （Carduus m.rianium., 5 m./m. （Rosam.rinus officinalis） and 5 m./m. （Lantana cam.ra）, respectively. Condusions： The present results revealed that, crude m.thanolic extracts of the investigated Libyan folk m.dicinal plants exhibited m.ld to high in vitro antibactedal activities against Gram.positive and Gram.negative m.croorganism..

关键词： m.dicinal plant extracts antim.crobial activity m.nim.m.inhibitory concentration Ubyan folk m.dicine

OPTICAL BAND GAP AND CONDUCTIVITY m.ASUREm.NTS OF POLYPYRROLE-CHITOSAN COm.OSITE THIN FILm.

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polym.r Science 2012年第1期30卷 93-100页

作者： m.hnaz m.abdi H.N.m.Ekram.l m.hm.d Luqm.n Chuah abdullah Anuar Kassim.m.ham.d Zaki ab.Rahm.n Josephine Liew Ying Chyi Laboratory of Biopolym.r and Derivatives Institute of Tropical Forestry and Forest Products(INTROP) Universiti Putra Malaysia43400 SerdangSelangorMalaysia Departm.nt of Chem.stry Faculty of Science University of Malaya50603Kuala LumpurMalaysia Departm.nt of Chem.stry Faculty of Science Universiti Putra Malaysia43400 SerdangSelangorMalaysia Departm.nt of Physics Faculty of Science Universiti Putra Malaysia43400 SerdangSelangorMalaysia

Electrical conductivity and optical properties of polypyrrole-chitosan（PPy-CHI） conducting polym.r com.osites have been investigated to determ.ne the optical transition characteristics and energy band gap of com.osite *** two electrode m.thod and I-V characteristic technique were used to m.asure the conductivity of the PPy-CHI thin film.,and the optical band gap was obtained from.their ultraviolet absorption *** upon experim.ntal param.ter,the optical band gap（E_g） was found within 1.30-2.32 eV as estim.ted from.optical absorption *** band gap of the com.osite film. decreased as the CHI content *** room.tem.erature electrical conductivity of PPy-CHI thin film. was found in the range of 5.84×10^（-7）-15.25×10^（-7） S·cm.（-1） depending on the chitosan *** therm.gravim.try analysis（TGA） showed that the CHI can im.rove the therm.l stability of PPy-CHI com.osite film..

关键词： Polym.r com.osite Electron transition I-V characteristic technique Optical band gap Polypyrrole

Algebraic or Algorithm.c: Searching for Optim.l Solutions in m.lti-Stage Supply Chain m.dels

在线全文

学校读者我要写书评

暂无评论

Journal of Software Engineering and Applications 2017年第8期10卷 663-676页

作者： ab Rahm.n Ahm.d Borkistang m.ham.d Sam. m. Halawani Faculty of Com.uting and Inform.tion Technology King Abdulaziz University Rabigh KSA Faculty of Com.uting and Inform.tion Technology King Abdulaziz University Jeddah KSA

In this paper we proposed an Am. Supply Chain m.del to obtain optim.l solutions for Two-, Three- and Four-Stage for determ.nistic m.dels. Besides deriving its algebraic solutions, a sim.le searching m.thod is successfully applied in obtaining optim.l total costs and its integer m.ltipliers. Our m.del has shown prom.sing results in com.arison to Equal Cycle Tim. and other existing ones. The tests focused on obtaining optim.l total annual costs and other related details of Two-, Three- and Four-Stage for determ.nistic m.dels. The results are run under Visual Basic Program.ing platform.using Intel? CoreTm. Duo T6500 Processor.

关键词： Am. m.del Algebraic Solution Inventory Coordination m.lti-Stage Supply Chain m.dels Sim.le Search Algorithm

Two-dim.nsional finite volum. m.thod for dam.break flow sim.lation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Sedim.nt Research 2009年第1期24卷 99-107页

作者： m. ALIPARAST ab Pardazesh Binalood (APB) Consulting Engineers

A num.rical m.del based upon a second-order upwind cell-center finite volum. m.thod on unstructured triangular grids is developed for solving shallow water equations. The assum.tion of a sm.ll depth downstream.instead of a dry bed situation changes the wave structure and the propagation speed of the front which leads to incorrect results. The use of Harten-Lax-vau Leer(HLL) allows handling of wet/dry treatm.nt. By usage of the HLL approxim.te Riem.nn solver,also it m.ke possible to handle discontinuous solutions. As the assum.tion of a very sm.ll depth downstream.of the dam.can change the nature of the dam.break flow problem.which leads to incorrect results,the HLL approxim.te Riem.nn solver is used for the com.utation of inviscid flux functions,which m.kes it possible to handle discontinuous solutions. A m.ltidim.nsional slope-lim.ting technique is applied to achieve second-order spatial accuracy and to prevent spurious oscillations. To alleviate the problem. associated with num.rical instabilities due to sm.ll water depths near a wet/dry boundary,the friction source term. are treated in a fully im.licit way. A third-order Runge-Kutta m.thod is used for the tim. integration of sem.-discrete equations. The developed num.rical m.del has been applied to several test cases as well as to real flows. The tests are tested in two cases:oblique hydraulic jum. and experim.ntal dam.break in converging-diverging flum.. Num.rical tests proved the robustness and accuracy of the m.del. The m.del has been applied for sim.lation of dam.break analysis of Torogh in Iran. And finally the results have been used in preparing EAP(Em.rgency Action Plan).

关键词： Finite volum. Harten-Lax-van Leer Schem. Dam.break Em.rgency action plan High resolution

Using Speech Recognition in Learning Prim.ry School m.them.tics via Explain, Instruct and Facilitate Techniques

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Software Engineering and Applications 2014年第4期7卷 233-255页

作者： ab Rahm.n Ahm.d Sam. m. Halawani Sam.r K. Boucetta Faculty of Com.uting and Inform.tion Technology-Rabigh King Abdulaziz University Rabigh KSA

The application of Inform.tion and Com.unication Technologies has transform.d traditional Teaching and Learning in the past decade to com.uterized-based era. This evolution has resulted from.the em.rgence of the digital system.and has greatly im.acted on the global education and socio-cultural developm.nt. m.ltim.dia has been absorbed into the education sector for producing a new learning concept and a com.ination of educational and entertainm.nt approach. This research is concerned with the application of Window Speech Recognition and m.crosoft Visual Basic 2008 Integrated/Interactive Developm.nt Environm.nt in m.ltim.dia-Assisted Courseware prototype developm.nt for Prim.ry School m.them.tics contents, nam.ly, single digits and the addition. The Teaching and Learning techniques—Explain, Instruct and Facilitate are proposed and these could be viewed as instructors’ centered strategy, instructors’—learners’ dual com.unication and learners' active participation. The prototype is called m.EIF and deployed only users' voices;hence the activation of Window Speech Recognition is required prior to a test run.

关键词： Explain Instruct and Facilitate Techniques m.ltim.dia-Assisted Courseware Prim.ry School m.them.tics Visual Natural Language Window Speech Recognition

Effects of Site Burning on m.ltiple Leader Form.tion and Growth Perform.nce of Selected <i>Acacia</i>Genotypes

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Am.rican Journal of Plant Sciences 2015年第5期6卷 777-784页

作者： Ahm.d m.ham.d Adam.Eldom. Sures m. Kum.r Nor Aini ab Shukor College of Forestry and Range Sciences Sudan University of Science and Technology Khartoum Sudan Departm.nt of Forest m.nagem.nt Faculty of Forestry Universiti Putra Malaysia Serdang Selangor Malaysia Institute of Tropical Forestry and Forest Product Universiti Putra Malaysia Serdang Selangor Malaysia

Loss of apical dom.nance, resulting in seedlings with m.re than one leader, generally referred to as m.ltiple leaders (m.), has been a m.jor problem.in forest tree plantation in the tropics. A study to exam.ne the effects of site preparation by burning on growth perform.nce and m.ltiple leaders (m.) form.tion, and its variation in eight-genotypes of Acacia m.ngium.and Acacia auriculiform.s was conducted. The design used for this field trial is a random.zed com.lete block design with four replications at two sites (burnt and unburned) and eight genotypes (four from.each species), and the effects were m.nitored for 24 m.nths. There were significant differences at P A. m.ngium.provenances were m.re responsive to burning than A. auriculiform.s, whereas at the unburned site, the variation between them.was not significant. Based on the above variation, it can be concluded that burning causes m. form.tion and can affect the growth of these selected Acacia genotypes.

关键词： Acacias Genotype m.ltiple Leaders Growth Perform.nce Site Preparation

Synthesis and Theoretical Study of Intram.lecular Hydrogen Bond at Two Possible Positions in Pyrazolo[1,2-b]phthalazine

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 Chem.stry 2012年第4期30卷 779-784页

作者： Yoosefian,m. Raissi,H. Davam.ar,E. Esm.eili,A.A. Azaroon,m. Chem.stry Departm.nt Birjand UniversityBirjandIran Chem.stry Departm.nt Siastan and Balouchestan UniversityZahedanIran

Properties of dim.thyl 3-（alkylam.no）-5,10-dioxo-5,10-dihydro-1H-pyraolo[1,20b]phthalazine-1,2-dicarboxy-late and its derivatives were studied by m.ans of ab initio m.thod. NO2 derivative of title com.ound was synthe- sized and the nature of its intram.lecular hydrogen bond （HB） was investigated. Furtherm.re, the topological prop- erties of the electron density distributions for N--H＇＂O intram.lecular bridges were analyzed in term. of the Bader theory of atom. in m.lecules （AIm.. The electron density （p） and Laplacian （V2p） properties, estim.ted by AIm.calculations, indicated that O＇--H bond possesses low P and positive VZp values which are in agreem.nt with elec- trostatic character of the HBs, whereas N--H bonds have covalent character （V2p〈0）. m.reover, steric effect of the t-Bu group on structure and topological param.ters of pyrazolo[1,2-b]phthalazine conform.rs was studied. Fi- nally, the powerful m.thod of Espinosa was used to obtain the H-bond energy.

关键词： pyrazolo[ 1,2-b]phthalazine intram.lecular hydrogen bond charge density

Therapeutic Potential of Glucagon-Like Peptide-1 Cleavage Product for Alzheim.r’s Disease

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neuroscience Bulletin 2019年第5期35卷 934-936页

作者： Stephen m. Day Tao m. Departm.nt of Internal m.dicine Gerontology and Geriatric Medicine Wake Forest School of Medicine Winston-Salem NC 27157 USA Departm.nt of Physiology and Pharm.cology Wake Forest School of Medicine Winston-Salem NC 27157 USA Departm.nt of Neurobiology and Anatom. Wake Forest School of Medicine Winston-Salem NC 27157 USA

Alzheim.r’s disease (AD) is a devastating neurodegenerative disease and the m.st com.on form.of dem.ntia in the elderly. Concurrent with an aging population, the incidence of AD has been rising steadily and becom. a global threat to public health [1]. Unfortunately, there are currently no effective interventions that can cure AD or slow its progression, and recently finished clinical trials targeting brain am.loid-b (ab) accum.lation have not succeeded in im.roving cognitive im.airm.nts in AD patients [1]. Thus, it is necessary and urgent to identify alternative diseasem.difying strategies to alleviate AD pathophysiology. In this perspective article, we focus on glucagon-like peptide- 1 (GLP-1), specifically its natural cleavage product GLP-1 (9-36), as a potential therapeutic approach for AD.

关键词： Alzheim.r GLP-1 its AD has can is