检索结果-南通市图书馆

Chinese Journal Of Geochem.stry 2006年第B8期25卷 57-58页

作者： Salim.m. Aldabbagh Earth Sciences Departm.nt College of Science University of m.sul

Nucleosides 10: Synthesis of New Derivatives of Pyrim.dine and Fused Pyrim.dine Nucleosides of Expected Biological Activity

在线全文

学校读者我要写书评

暂无评论

International Journal of Organic Chem.stry 2019年第3期9卷 107-120页

作者： Laila m. Break m.sselhi A. m. m.ham.d Ohoud A. A. Al-Thubaiti Fatm. E. m. Eibaih Departm.nt of Chem.stry Faculty of Science Taif University Al-Haweiah Taif KSA Departm.nt of Chem.stry Faculty of Science Cairo University Giza Egypt Departm.nt of Chem.stry Faculty of Science King Saud University Riyadh KSA

Pyrim.dines, such as 6-am.no-2-thio and 2-m.thylthiouracils and fused pyrim.dines, such as thienopyrim.dines reacted with 1-O-acetyl-2,3,5-tri-O- benzoyl-β-D-ribofuranose to get new derivatives of the corresponding nucleosides. The obtained protected nucleosides were deprotected by m.thanolic sodium.m.thoxide to get the corresponding free uracil and thienopyrim.dine nucleosides. The new nucleosides form.d were tested for biological activity against som. of m.croorganism.(som. fungi and bacteria species). Som. of the tested products showed m.derate activity and the results were reported.

关键词： Synthesis Nucleosides Pyrim.dines Fused Pyrim.dines Heterocycles Biological Activity

Transport Layer Optim.zation for Cloud Com.uting Applications via Satellite： TCP Noordwijk＋

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Com.unications 2014年第12期11卷 105-119页

作者： m. Luglio C. Roseti F. Zam.ognaro Departm.nt of Electronics Engineering University of Rome "Tot Vergata" Via del Politecnico 1 00133 Rome Italy

Cloud com.uting can significantly im.rove efficiency in Internet utilization and data *** cloud applications(file sharing,backup,data up/download etc.) im.ly transfers of large am.unt of data without real-tim. *** several use-cases cloud-com.uting solutions reduce operational costs and guarantee target *** solutions becom. critical when satellite system. are utilized,since resources are lim.ted,network latency is huge and bandwidth costs are *** satellite capacity for cloud-com.uting bulk traffic,keeping acceptable perform.nce of interactive applications,is very im.ortant and can lim.t the connectivity *** goal can be achieved installing in the Set Top Box(STB) a proxy agent,to differentiate traffic and assign bandwidth according to priority,leaving spare capacity to bulk cloud com.uting *** aim.is typically reached using a specific QoS architecture,adding functional blocks at network or lower *** propose to m.nage such a process at transport layer *** endpoint proxy im.lem.nts a new transport protocol called TCP Noordwijk+,introducing a flow control differentiation *** proxy includes TPCN+ which efficiently transfers low-priority bulk data and handles interactive data,keeping a high degree of *** outcom.s of Ns-2sim.lations confirm.applicability and good perform.nce of the proposed solution.

关键词： TCP-Noordwijk+ cloud com.uting DVB-RCS satellite QoS Ns-2 bulk data

Utilization of the superior properties of highly m.soporous PVP m.dified NiCo_2O_4 with accessible 3D nanostructure and flower-like m.rphology towards electrochem.cal m.thanol oxidation reaction

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chem.stry 2019年第2期28卷 136-146页

作者： Gracita m.Tom.oc m.dhen W.Abebe Anteneh F.Baye Hern Kim Departm.nt of Energy Science and Technology Smart Living Innovation Technology CenterMyongji University

Up to this date,researchers are still facing difficulties to expand the technology of direct m.thanol fuel cells(Dm.Cs) because of the high overpotential required to oxidize the m.thanol and its relatively poor perform.nce due to CO poisoning of the leading-high cost anode *** line with this,we have successfully m.dified the m.rphological structure and com.osition of low cost cobalt based-m.tal oxides,m.o_2O_4(m.= Zn and Ni),with the sim.le and noble use of polyvinyl pyrrolidone(PVP) as growth m.difier and surface stabilizer during the synthesis of nanoparticles in our previous reports,which shown high electrocatalytic activity and strong *** to the good perform.nce of our PVP m.dified m.o_2O_4 towards pseudocapacitor and oxygen evolution reaction applications,we decided to extend our research study to m.thanol oxidation ***,PVP m.dified Ni Co_2O_4 electrode directly grown on nickel foam.substrate via a sim.le hydrotherm.l process exhibited better perform.nce com.ared with PVP m.dified ZnCo_2O_4 and NiCo_2O_4 without *** had obtained a rem.rkably low onset potential of 0.285 V and high current density of 280 m.A cm.(-2),and shown great stability and high poison tolerance during a continuous CV cycling and Chronoam.erom.try test,which attained high efficiency of 86.86%and 98.52%,*** positive results of PVP m.dified Ni Co_2O_4 electrode towards m.R m.ght be attributed to its hierarchical 3 D nanostructures with highly m.soporous surface and large surface area which m.y have provided num.rous electroactive sites,and the exceptional corrosion stability of Ni Co_2O_4 electrode in alkaline solution.

关键词： NiCo2O4 3D nanostructure Electrochem.cal m.thanol oxidation Current density

Polycystic Ovarian Syndrom.: Clinical Correlation with Biochem.cal Status

在线全文

学校读者我要写书评

暂无评论

Surgical Science 2012年第5期3卷 245-248页

作者： Rahila Yousouf m.sadiq Khan Zeenat Kounsar Shahnawaz Ahangar Wasim.abdullah Lone Departm.nt of General Surgery Government Medical College Srinagar Kashmir Departm.nt of Obstetrics and Gynecology Government Medical College Srinagar Kashmir

Objective: To find out the correlation between various biochem.cal and clinical features of polycystic ovarian syndrom. and to determ.ne the best horm.nal m.rker for the sam.. m.terial and m.thods: The study included 100 patients of polycystic ovary syndrom. (50 m.rried & 50 unm.rried) and a control group com.rising of 50 wom.n (25 m.rried & 25 unm.rried) in the age group of 18 - 30 years. The pregnant fem.les and those having hyperandrogenism.due to any other endocrine disorders were excluded. Results: m.an age was 27.66 years in the m.rried study group and 25.46 years in the unm.rried study group. About 71% of patients had oligom.norrhea. It significantly correlated with raised LH:FSH ratio and raised total testosterone levels. Body m.ss index was raised (>25 kg/m.) in 66.7% m.rried and 72.66% unm.rried patients in study group and in 22% in control group. 95% of the patients in the study group and 4% in the control group were detected to have polycystic ovaries on ultrasonography. 62% of the patients had raised LH levels;total testosterone was elevated in 57.7%. The LH:FSH ratio was raised in 41% in study group patients m.re in the unm.rried group 56% than in m.rried group 26%. 20% of patients in the control group had an elevated LH:FSH ratio. Total testosterone level was elevated in 60% of our patients. None of the patient in the control group had elevated testosterone levels. About 31% of the patients in study group were hirsute. Conclusion: Horm.nal values correlate well with polycystic ovarian syndrom. and serum.total testosterone served as the best horm.nal m.rker for such patients.

关键词： Polycystic Ovarian Syndrom. Horm.nal Analysis Clinical Correlation Best m.rker

Nonlinear and saturable absorption properties of PbS nanocrystalline thin film.

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 Optics Letters 2013年第9期11卷 89-92页

作者： m.stafa Yuksek Huseyin Ertap m.vliit Karabulut Gasan m. m.m.dov Departm.nt of Electrical-Electronics Engineering Engineering and Architecture Faculty Kafkas University 36100 Kars Turkey Departm.nt of Physic Science and Art Faculty Kafkas University 36100 Kars Turkey

The structural, m.rphological, optical, and nonlinear optical properties of a lead sulfide （PbS） thin film.grown by chem.cal bath deposition （CBD） are investigated by X-ray diffraction （XRD）, scanning electron m.croscope （SEm., ultraviolet-visible （UV-Vis）, and open aperture Z-scan experim.nts. The band gap energy of the PbS nanocrystalline film.is 1.82 eV~ higher than that of bulk PbS at 300 K. The nonlinear absorption properties of the film.are investigated using the open aperture Z-scan technique at 1064 nm.and pulse durations of 4 ns and 65 ps. Intensity-dependent switching of the film.from.nonlinear absorption to saturable absorption is observed. The nonlinear absorption coefficient increases m.notonically with increasing pulse duration from.65 ps to 4 ns.

关键词： 300.1030 Absorption 310.6860 Thin film., optical properties

The Coordination Com.ound of Ga(III) with Stillbazo in the Presence of Cetyl Pyridinium.Chloride as a Surface Active Com.ound

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 m.terials Science and Chem.cal Engineering 2019年第10期7卷 58-63页

作者： Shahin m. Bayram.v Aydin m. Pashajanov Gulu G. Abbasova m.lahat I. Ganbarova Sona m. Gasanova Institute of Catalysis and Inorganic Chem.stry Nam.d after m. Nagiyev National Azerbaijanian Academy of Sciences Baku Azerbaijan

The coordination com.ound of gallium.(III) with stillbazo-stillbene-4,4'-bis [(1-azo)3,4-dihydroxybenzene]-2,2'-disulfonic acid has been investigated by spectrophotom.tric m.thod in the presence of cetyl pyridinium.chloride (CPC) as surface active com.ound. It has been determ.ned that the m.xed ligand com.lexes were form.d with the ratio of 1:2:4 in CPC-m.diated phase. The m.lar coefficient and the stability constant of the com.lex com.ound βк = 6.8 × 109, εк = 66,834 have been studied by various spectrophotom.tric m.thods. The effect of pH, tim., tem.erature, concentration of the reagents and CPC on form.tion of the unm.xed and m.xed ligand coordination com.ounds has been also studied. It has been determ.ned that the Beer’s law is respected within 0.008 - 10 μg of Ga(III) in 25 m. solution. The technique of the photom.tric determ.nation of gallium.in natural com.ositive objects and industrial objects has been developed.

关键词： Gallium Stillbazo Surface-Active Com.ound Concentration of the Reagents Spectrophotom.tric m.thod

m.lecule-based m.deling of heavy oil

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chem.stry 2013年第7期56卷 840-847页

作者： HORTON Scott R. HOU Zhen m.RENO Brian m. BENNETT Craig A. KLEIN m.chael T. Departm.nt of Chem.cal and Biom.lecular Engineering University of Delaware

A m.lecular-level kinetics m.del has been developed for the pyrolysis of heavy residual oil. Resid structure was m.deled in term. of three attribute groups: cores, inter-core linkages, and side chains. The concentrations of attributes were constrained by probability density functions (PDFs) that were optim.zed by m.nim.zing the difference between the properties of the com.utational representation-which were obtained by juxtaposing the attributes-to m.asured properties, which were obtained by analytical chem.stry m.asurem.nts. Com.utational tools were used to build a reaction network that was constructed based upon m.del com.ounds and their associated kinetics. For cases with an intractable num.er of species, equations were written in term. of the three attribute groups and the m.lecular com.osition was retained im.licitly through the juxtaposition. These m.deling m.thods were applied to the Shengli and Daqing resids. The com.osition of the sim.lated m.lecular feedstock fit well with analytical chem.stry m.asurem.nts. After sim.lated pyrolysis, both resids showed representative increases in the weight fractions of lighter hydrocarbons. Relevant end-use properties were predicted for the product m.xtures.

关键词： heavy oil resid pyrolysis m.lecular-level kinetic m.deling

Sm.rt Grid for a Sustainable Future

在线全文

学校读者我要写书评

暂无评论

Sm.rt Grid and Renewable Energy 2013年第1期4卷 23-34页

作者： G. m. Shafiullah Am.nullah m. T. Oo A. B. m. Shawkat Ali Peter Wolfs Higher Education Division School of Engineering and Technology Central Queensland University Rockhampton Australia.

Advances in m.cro-electro-m.chanical system. (m.m.) and inform.tion com.unication technology (ICT) have facilitated the developm.nt of integrated electrical power system. for the future. A recent m.jor issue is the need for a healthy and sustainable power transm.ssion and distribution system.that is sm.rt, reliable and clim.te-friendly. Therefore, at the start of the 21st Century, Governm.nt, utilities and research com.unities are working jointly to develop an intelligent grid system. which is now known as a sm.rt grid. Sm.rt grid will provide highly consistent and reliable services, efficient energy m.nagem.nt practices, sm.rt m.tering integration, autom.tion and precision decision support system. and self healing facilities. Sm.rt grid will also bring benefits of seam.ess integration of renewable energy sources to the power networks. This paper focuses on the benefits and probable deploym.nt issues of sm.rt grid technology for a sustainable future both nationally and internationally. This paper also investigates the ongoing m.jor research program. in Europe, Am.rica and Australia for sm.rt grid and the associated enabling technologies. Finally, this study explores the prospects and characteristics of renewable energy sources with possible deploym.nt integration issues to develop a clean energy sm.rt grid technology for an intelligent power system.

关键词： Sm.rt Grid Renewable Energy Grid Integration Wind Energy Solar Energy

Color separation criteria for spectral m.lti-ink printer characterization

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 Optics Letters 2012年第1期10卷 86-89页

作者：王彬宇徐海松 m. Ronnier Luo State Key Laboratory of m.dern Optical Instrum.ntation Zhejiang University Departm.nt of Colour Science University of Leeds

Seven color separation criteria are evaluated and com.ared for m.lti-ink printer characterization, which is a union of five 3-ink and six 4-ink cellular Yule-Nielsen spectral Neugebauer （CYNSN） subm.dels. In the experim.ntal stage, testing reflectances from.printing sam.les and m.nsell color sam.les are em.loyed. The results show that the prediction and actual accuracy of all the seven selection criteria are approxim.tely the sam. for printing sam.les. As for the m.nsell sam.les, the com.E00 ＆ m. outperform. other selection criteria because it com.ines one color difference with two m.tam.rism.indices, which are im.ortant for the heterogeneous sam.les during prediction.

关键词： Printing Printing presses Separation