检索结果-南通市图书馆

Petroleum Science 2024年第4期21卷 2469-2474页

作者： j.mes j.Sheng Er-Long Yang College of Petroleum Engineering Northeast Petroleum University

During air inj.ction into an oil reservoir, an oxidation reaction generates some heat to raise the reservoir temperature. When the reservoir temperature reaches an ignition temperature, spontaneous ignition occurs. There is a time delay from the inj.ction to ignition. There are mixed results regarding the feasibility of spontaneous ignition in real-field proj.cts and in laboratory experiments. No analytical model is available in the literature to estimate the oxidation time req.ired to reach spontaneous ignition with heat *** paper discusses the feasibility of spontaneous ignition from theoretical points and experimental and field proj.ct observations. An analytical model considering heat loss is proposed. Analytical models with and without heat loss investigate the factors that affect spontaneous ignition. Based on the discussion and investigations, we find that it is more difficult for spontaneous ignition to occur in laboratory experiments than in oil reservoirs; spontaneous ignition is strongly affected by the initial reservoir temperature, oil activity, and heat loss; spontaneous ignition is only possible when the initial reservoir temperature is high, the oil oxidation rate is high, and the heat loss is low.

关键词： Spontaneous ignition Time delay Air inj.ction Heat loss Low temperature oxidation Combustion

KINETIC STUDY OF SPINEL LiMn_2O_4 SYNTHESIZED BY SOLID REACTION WITH SOFT-CHEMICAL METHOD

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2005年第4期18卷 512-518页

作者： C.q. Xu Y. W. Tian Y. C. Zhai Z.j. Guo Z. q. Huang School of Materials and Metallurgy Northeastern University Shenyang 110004 China

The differential thermal analysis （DTA） curves were measured at different heating rates in flowing air for studying the synthesis of the spinel LiMn2O3 with Li2CO3 and MnO2, The reaction began at about 503K, and finished at about 873K. The apparent activation energy of Kissinger method was about ***^-1, the reaction orderwas 1.67, the freq.ency factor was 7.81×10^9, and therefore the dinetic epuation was dδ/dt=A·exp（- E/RT）·（1-δ）^n=7.81×10^9, exp（-122770/RT）·（l-δ）^1.67 . Coats-Redfem integral method was used to analyze the DTA curves of the samples at different heating rates, and the calculated apparent activation energy and freq.ency factor were 112. 13kj. mol^-1 and 1.18 × 10^9, respectively, rather close to that of Kissinger method. X-ray diffraction （XRD） and scanning electron microscope （SEM） results shown that the synthesized LiMn2O3 possesses pure phase, regular shape and normal particle distribution.

关键词： lithium manganese oxides synthesized kinetics Kissinger method,Coats-Redfern integral method

ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY STUDY OF CORROSION INHIBITION OF MODIFIED LIGNOSULPHONATE FOR CARBON STEEL

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2005年第4期18卷 519-524页

作者： C.H. Yi X. q. q.u D.j. Yang H.M. Lou College of Chemical and Energy Engineering South China University of TechnologyGuangzhou 510640 China

The corrosion inhibition for carbon steel in circulating cooling water by modified lignosulphonate has been investigated using electrochemical impedance spectroscopy techniq.e. Results show that the inhibition efficiency of modified lignosulphonate GCL2 is a great improvement on that of lignosulphonate. The maximum inhibition efficiency of GCL2 reaches 99.21% at the concentration of 400mg·L^-1 at 303K. The corrosion inhibition of GCL2 is attributed to forming adsorption film on the metal surface for the electrochemical impedance spectroscopy in GCL2 solution shows more than one ***,results also indicate that it is more efficient in stirring solution than in still solution for GCL2 because the constant of adsorption in stirring solution is much larger than that in still solution. The adsorption of inhibitor GCL2 follows Langmuir＇s adsorption isotherm.

关键词： electrochemical impedance spectroscopy EIS corrosion inhibition modified lignosulphonate

[Na(DB18-C-6)(H2O)2][Na(DB18-C-6)(SCN)2]：Two-Di-mensional Network Complex Assembled by π-π Stacking Interactios,Hydrogen Bonds and Electrostatic Interactions

在线全文

学校读者我要写书评

暂无评论

Chinese j.urnal of Chemistry 2002年第5期20卷 424-426页

作者： Zhu D.-Z. Song X.-M. Dou j.-M. Liu Y. Wang D.-q. Department of Chemistry Liaocheng Teacher's College Liaocheng 252000 China

A novel two-dimensional network dibenzo-18-crown-6 (DB18-C-6) complex: [Na(DB18-C-6) (H2O)2] [Na(DB18-C-6) (SCN)2] has been isolated and characterized by elemental, IR and X-ray diffraction analysis. The crystal structure belongs to monoclinic, space group P2 1/c with cell dimensions a = 1.06178(7), b = 1.40243(8), c = 3.03496(19) nm, β = 90.4220(10)°, V = 4.5292(5) nm3, Z = 4, Dcalcd = 1.351 g/cm3, F(000) = 1936, R1 = 0.0369, wR2 = 0.0821. The most interesting feature in this structure is that complex cation and complex anion form a two-dimensional network via π-π stacking interactions, hydrogen bonds and electrostatic interactions.

关键词： Crown ether Crystal structure DB18-crown-6 Hydrogen bonds π-π stacking interactions

Amplitude analysis of the decays D^(0)→π^(+)π^(−)π^(+)π^(−)and D^(0)→π^(+)π^(−)π^(0)π^(0)

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2024年第8期48卷 6-33页

作者： M.Ablikim M.N.Achasov P.Adlarson O.Afedulidis X.C.Ai R.Aliberti A.Amoroso q.An Y.Bai O.Bakina I.Balossino Y.Ban H.-R.Bao V.Batozskaya K.Begzsuren N.Berger M.Berlowski M.Bertani D.Bettoni F.Bianchi E.Bianco A.Bortone I.Boyko R.A.Briere A.Brueggemann H.Cai X.Cai A.Calcaterra G.F.Cao N.Cao S.A.Cetin j.F.Chang W.L.Chang G.R.Che G.Chelkov C.Chen C.H.Chen Chao Chen G.Chen H.S.Chen M.L.Chen S.j.Chen S.L.Chen S.M.Chen T.Chen X.R.Chen X.T.Chen Y.B.Chen Y.q.Chen Z.j.Chen Z.Y.Chen S.K.Choi X.Chu G.Cibinetto F.Cossio j.j.Cui H.L.Dai j.P.Dai A.Dbeyssi R.E.de Boer D.Dedovich C.q.Deng Z.Y.Deng A.Denig I.Denysenko M.Destefanis F.De Mori B.Fang S.S.Fang W.X.Fang Y.Fang Y.q.Fang R.Farinelli L.Fava F.Feldbauer G.Felici C.q.Feng j.H.Feng Y.T.Feng K.Fischer M.Fritsch C.D.Fu j.L.Fu Y.W.Fu H.Gao Y.N.Gao Yang Gao S.Garbolino I.Garzia P.T.Ge Z.W.Ge C.Geng E.M.Gersabeck B.Ding X.X.Ding Y.Ding Y.Ding j.Dong L.Y.Dong M.Y.Dong X.Dong M.C.Du S.X.Du Z.H.Duan P.Egorov Y.H.Fan j.Fang j..Gilman K.Goetzen L.Gong W.X.Gong W.Gradl S.Gramigna M.Greco M.H.Gu Y.T.Gu C.Y.Guan Z.L.Guan A.q.Guo L.B.Guo M.j.Guo R.P.Guo Y.P.Guo A.Guskov j.Gutierrez K.L.Han T.T.Han X.q.Hao F.A.Harris K.K.He K.L.He F.H.Heinsius C.H.Heinz Y.K.Heng C.Herold T.Holtmann P.C.Hong G.Y.Hou X.T.Hou Y.R.Hou Z.L.Hou B.Y.Hu H.M.Hu j.F.Hu T.Hu Y.Hu G.S.Huang K.X.Huang L.q.Huang X.T.Huang Y.P.Huang T.Hussain F.H\"olzken N.H\"usken N.in der Wiesche M.Irshad j.j.ckson S.j.nchiv j.H.j.ong q.j. q.P.j. W.j. X.B.j. X.L.j. Y.Y.j. X.q.j.a Z.K.j.a D.j.ang H.B.j.ang P.C.j.ang S.S.j.ang T.j.j.ang X.S.j.ang Y.j.ang j.B.j.ao j.K.j.ao Z.j.ao S.j.n Y.j.n M.q.j.ng X.M.j.ng T.j.hansson S.Kabana N.Kalantar-Nayestanaki X.L.Kang X.S.Kang M.Kavatsyuk B.C.Ke V.Khachatryan A.Khoukaz R.Kiuchi O.B.Kolcu B.Kopf M.Kuessner X.Kui A.Kupsc W.K\"uhn j.j.Lane P.Larin L.Lavezzi T.T.Lei Z.H.Lei H.Leithoff M.Lellmann T.Lenz C.Li C.Li C.H.Li Cheng Li D.M.Li F.Li G.Li H.Li H.B.Li H.j.Li H.N.Li Hui Li j.R.Li j.S.Li K.Li L.j.Li L.K.Li Lei Li M.H.Li P.R.Li q.M.Li q.X.Li R.Li S.X.Li T.Li W.D.Li W.G.Li X.Li X.H.Li X.L.Li X.Y.Li Y Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China Beihang University Beijing 100191China Bochum Ruhr-University D-44780 BochumGermany Budker Institute of Nuclear Physics SB RAS(BINP) Novosibirsk 630090Russia Carnegie Mellon University PittsburghPennsylvania 15213USA Central China Normal University Wuhan 430079China Central South University Changsha 410083China China Center of Advanced Science and Technology Beijing 100190China China University of Geosciences Wuhan 430074China Chung-Ang University Seoul06974Republic of Korea COMSATS University Islamabad Lahore CampusDefence RoadOff Raiwind Road54000 LahorePakistan Fudan University Shanghai 200433China GSI Helmholtzcentre for Heavy Ion Research GmbH D-64291 DarmstadtGermany Guangxi Normal University Guilin 541004China Guangxi University Nanning 530004China Hangzhou Normal University Hangzhou 310036China Hebei University Baoding 071002China Helmholtz Institute Mainz Staudinger Weg 18D-55099 MainzGermany Henan Normal University Xinxiang 453007China Henan University Kaifeng 475004China Henan University of Science and Technology Luoyang 471003China Henan University of Technology Zhengzhou 450001China Huangshan College Huangshan 245000China Hunan Normal University Changsha 410081China Hunan University Changsha 410082China Indian Institute of Technology Madras Chennai 600036India Indiana University BloomingtonIndiana 47405USA INFN Laboratori Nazionali di Frascati INFN Laboratori Nazionali di FrascatiI-00044FrascatiItaly INFN Laboratori Nazionali di Frascati INFN Sezione di PerugiaI-06100PerugiaItaly INFN Laboratori Nazionali di Frascati University of PerugiaI-06100PerugiaItaly INFN Sezione di Ferrara INFN Sezione di FerraraI-44122FerraraItaly INFN Sezione di Ferrara University of FerraraI-44122FerraraItaly Inner Mongolia University Hohhot 010021China Institute of Modern Physics Lanzhou 730000China Institute of Physics and Technology Peace Avenue 54BUlaanbaatar 13330Mongolia Instituto de A

Using e^(+)e^(−)annihilation data corresponding to an integrated luminosity of 2.93 fb^(−1)taken at the center-of-mass energy√s=3.773 GeV with the BESIII detector,a j.int amplitude analysis is performed on the decays D^(0)→π^(+)π^(−)π^(+)π^(−)and D^(0)→π^(+)π^(−)π^(0)π^(0)(non-η).The fit fractions of individual components are obtained,and large interferences among the dominant components of the decays D^(0)→a_(1)(1260)π,D^(0)→π(1300)π,D^(0)→ρ(770)ρ(770),and D^(0)→2(ππ)_(S)are observed in both *** the obtained amplitude model,the CP-even fractions of D^(0)→π^(+)π^(−)π^(+)π^(−)and D^(0)→π^(+)π^(−)π^(0)π^(0)(non-η)are determined to be(75.2±1.1_(stat).±1.5_(syst.))%and(68.9±1.5_(stat).±2.4_(syst.))%,*** branching fractions of D^(0)→π^(+)π^(−)π^(+)π^(−)and D^(0)→π^(+)π^(−)π^(0)π^(0)(non-η)are measured to be(0.688±0.010_(stat.)±0.010_(syst.))%and(0.951±0.025_(stat.)±0.021_(syst.))%,*** amplitude analysis provides an important model for the binning strategy in measuring the strong phase parameters of D^(0)→4πwhen used to determine the CKM angleγ(ϕ_(3))via the B^(−)→DK^(−)decay.

关键词： BESIII D^(0)meson decays amplitude analysis CP-even fraction

External-Cavity Tunable Laser Using MEMS Technology

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

光学学报 2003年第S1期23卷 433-434页

作者： j. Z. Hao X. M. Zhang C. Lu A. q. Liu Institute for Infocomm Research Unit 230 Innovation Center Block 2 18 Nanyang Drive Singapore 639798School of Electrical & Electronic Engineering Nanyang Technological University Nanyang Avenue Singapore 639798School of Electrical & Electronic Engineering Nanyang Technological University Nanyang AvenueSingapore 639798 Institute for Infocomm Research Unit 230 Innovation Center Block 2 18 Nanyang Drive Singapore 639798School of Electrical & Electronic Engineering Nanyang Technological University Nanyang Avenue Singapore 639798

This paper introduces a tunable external-cavity diode laser using a MEMS vertical mirror fabricated on a silicon-on-insulator (SOI) wafer. This laser has the merits of simple alignment process, easy integration/packag... 详细信息

关键词： MEMS as in on be with External-Cavity Tunable Laser Using MEMS Technology for mode of dBm from

Acasta片麻杂岩多期次热事件:来自锆石、榍石和磷灰石的原位微区年代学证据

在线全文

学校读者我要写书评

暂无评论

中国科学：地球科学 2024年第3期54卷 693-707页

作者：梅清风杨进辉孙金凤李秋立吴石头凌潇潇彭澎王浩中国科学院地质与地球物理研究所岩石圈演化国家重点实验室北京100029 中国科学院大学地球与行星科学学院北京100049 中国科学院大学计算地球动力学重点实验室北京100049

本文使用激光剥蚀电感耦合等离子体质谱(LA-ICPMS)和二次离子质谱(SIMS)对Acasta片麻杂岩样品碎片(大小约1cm2)中的锆石、磷灰石和榍石进行了原位微区定年,以制约Acasta片麻杂岩的热演化历史.这些样品碎片中的锆石显示多期年龄,反映了... 详细信息

本文使用激光剥蚀电感耦合等离子体质谱(LA-ICPMS)和二次离子质谱(SIMS)对Acasta片麻杂岩样品碎片(大小约1cm2)中的锆石、磷灰石和榍石进行了原位微区定年,以制约Acasta片麻杂岩的热演化历史.这些样品碎片中的锆石显示多期年龄,反映了继承锆石的存在或者锆石结晶后的再生长过程.结合前人研究,本文锆石数据揭示, Acasta片麻杂岩经历的多期岩浆事件发生时间分别为:>3.96、约3.72和约3.57Ga.样品AY199中榍石的PbPb等时线年龄为(2911±22)Ma(95%置信水平, MSWD=1.5),与Acasta片麻杂岩记录的太古宙最后一次岩浆事件年龄一致.样品AC478和AY066中榍石U-Pb年龄分别为(1932±270)Ma(95%置信水平, MSWD=2.3)和(1813±45)Ma(95%置信水平, MSWD=2.3).样品P090803-C中磷灰石的Pb-Pb等时线年龄为(1833±26)Ma(95%置信水平,MSWD=1.4).样品AC478、AY199和AY066中磷灰石U-Pb年龄分别为(1850±20)Ma(95%置信水平, MSWD=1.3)、(1827±100)Ma(95%置信水平, MSWD=6.3)和(1807±58)Ma(95%置信水平, MSWD=3.9).样品AC478和AY066中的榍石U-Pb年龄以及本文所有样品中的磷灰石Pb-Pb或U-Pb年龄相同,均为约1.9~1.8Ga,指示Wopmay造山作用导致的矿物U-Pb体系重置,证明了Wopmay造山作用的峰期温度超过了磷灰石的U-Pb体系封闭温度,并接近或者超过榍石的U-Pb体系封闭温度.

关键词：锆石榍石磷灰石 Acasta片麻杂岩 Wopmay造山带

Optimization of N18 Zirconium Alloy for Fuel Cladding of Water Reactors

在线全文

学校读者我要写书评

暂无评论

j.urnal of Materials Science & Technology 2012年第7期28卷 606-613页

作者： B.X. Zhou M. Y. Yao Z.K. Li X.M. Wang j. Zhoua C.S. Long q. Liu B.F. Luan Laboratory for Mierostructures Shanghai University Shanghai 200444 China Institute of Materials Shanghai University Shaxighai 200072 China Northwest Institute for Non-ferrous Metal Research Xian 721014 China Key Laboratory for Nuclear Fuel and Materials Nuclear Power Institute of China Chengdu 610041 China College of Material Science and Engineering Chongqing University Chongqing 400044 China

In order to optimize the microstructure and composition of N18 zirconium alloy （Zr-1Sn-0.35Nb-0.35Fe-0.1Cr, in mass fraction, %）, which was developed in China in 1990s, the effect of microstructure and composition variation on the corrosion resistance of the N18 alloy has been investigated. The autoclave corrosion tests were carried out in super heated steam at 400 ~C/10.3 MPa, in deionized water or lithiated water with 0.01 mol/L LiOH at 360 ~C/18.6 MPa. The exposure time lasted for 300-550 days according to the test temperature. The results show that the microstructure with a fine and uniform distribution of second phase particles （SPPs）, and the decrease of Sn content from 1% （in mass fraction, the same as follows） to 0.8% are of benefit to improving the corrosion resistance; It is detrimental to the corrosion resistance if no Cr addition. The addition of Nb content with upper limit （0.35%） is beneficial to improving the corrosion resistance. The addition of Cu less than 0.1% shows no remarkable influence upon the corrosion resistance for N18 alloy. Comparing the corrosion resistance of the optimized N18 with other commercial zirconium alloys, such as Zircaloy-4, ZIRLO, E635 and Ell0, the former shows superior corrosion resistance in all autoclave testing conditions mentioned above. Although the data of the corrosion resistance as fuel cladding for high burn-up has not been obtained yet, it is believed that the optimized N18 alloy is promising for the candidate of fuel cladding materials as high burn-up fuel assemblies. Based on the theory that the microstructural evolution of oxide layer during corrosion process will affect the corrosion resistance of zirconium alloys, the improvement of corrosion resistance of the N18 alloy by obtaining the microstructure with nano-size and uniform distribution of SPPs, and by decreasing the content of Sn and maintaining the content of Cr is discussed.

关键词： Zirconium alloys Corrosion resistance Composition variation Microstructure

A Spectrum Sensing Framework for UWB-Cognitive Network

在线全文

学校读者我要写书评

暂无评论

Wireless Sensor Network 2010年第8期2卷 649-654页

作者： Deah j. Kadhim Saba q. j.bbar 不详

Due to that the Ultra Wide Band (UWB) technology has some attractive features like robustness to multipath fading, high data rate, low cost and low power consumption, it is widely use to implement cognitive radio network. Intuitively, one of the most important tasks req.ired for cognitive network is the spectrum sensing. A framework for implementing spectrum sensing for UWB-Cognitive Network will be presented in this paper. Since the information about primary licensed users are known to the cognitive radios then the best spectrum sensing scheme for UWB-cognitive network is the matched filter detection scheme. Simulation results verified and demonstrated the using of matched filter spectrum sensing in cognitive radio network with UWB and proved that the bit error rate for this detection scheme can be considered acceptable.

关键词： Cognitive Radio UWB Spectrum Sensing Matched Filter

Microstructure and mechanical optimization of probeless friction stir spot welded j.int of an Al-Li alloy

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

j.urnal of Materials Science & Technology 2018年第10期34卷 1739-1746页

作者： q. Chu W.Y. Li X.W. Yang j.j. Shen A. Vairis W.Y. Feng W.B. Wang State Key Laboratory of Solidification Processing Shaanxi Key Laboratory of Friction Welding Technologies Northwestern Polytechnical University Xi'an710072 China Helmholtz-Zentrum Geesthacht Institute of Materials Research Materials Mechanics Geesthacht 21502 Germany Mechanical Engineering Department TEl of Crete Heraklion Crete 71004 Greece China PSW Center Beijing 100024 China

In this work, a third generation AI-Li alloy has been successfully spot welded with probeless friction stir spot welding （P-FSSW）, which is a variant of conventional friction stir welding. The Box-Behnken exper-imental design in response surface methodology （RSM） was applied to optimize the P-FSSW parameters to attain maximum tensile/shear strength of the spot j.ints. Results show that an optimal failure load of 7.83 kN was obtained under a dwell time of 7.2 s, rotation speed of 950 rpm and plunge rate of 30 mm/rain. Sufficient dwell time is essential for heat conduction, material flow and expansion of the stir zone to form a sound j.int. Two fracture modes were observed, which were significantly affected by hook defect. In addition to mechanical testing, electron backscattering diffraction （EBSD） and differential scanning calorimetry （DSC） were used for microstructure evolution and property analysis. The precipitation of GP zone and AI3Li as well as the ultrafine grains were responsible for the high microhardness in the stir zone.

关键词： Probeless friction stir spot welding Precipitation Mechanical property Fracture mechanism