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Extraction of copper ions by.supercritical carbon dioxide

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Journal of Environmental Sciences 2000年第4期12卷 444-447页

作者： Cui, z. Liu, J. Gao, L. Wei, y. Dept. of Environmental Engineering Shandong University Jinan 250100 China

Complexation combined with supercritical fluid extraction was used to extract Cu2+ in this study. The effects of pressure, temperature, volume of CO2 on the efficiency.of extraction were sy.tematically.investigated. At the optimum condition a 57.32% recovery.was achieved. Addition of suitable amount of methanol (v/v = 5%) to the supercritical CO2 can increase in the extraction of Cu2+ (72.69%, RSD = 2.12%, n = 3). And the recovery.can further increase in the presence of non-ionic surfactant Triton X-100 because of its function of solubiliz.tion. Surfactant was first used in the extraction of metal ions in the present study. and the results are satisfied (90.52%, RSD = 2.20%, n = 3).

关键词： Carbon dioxide Chelation Copper Methanol Positive ions Pressure effects Solubility Surface active agents Thermal effects

KINETIC STUDy.OF SPINEL LiMn_2O_4 Sy.THESIz.D By.SOLID REACTION WITH SOFT-CHEMICAL METHOD

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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. z.ai z.J. Guo z. Q. Huang School of Materials and Metallurgy Northeastern University Shenyang 110004 China

The differential thermal analy.is （DTA） curves were measured at different heating rates in flowing air for study.ng the sy.thesis 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 frequency.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 analy.0} the DTA curves of the samples at different heating rates, and the calculated apparent activation energy.and frequency.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 sy.thesiz.d LiMn2O3 possesses pure phase, regular shape and normal particle distribution.

关键词： lithium manganese oxides sy.thesiz.d kinetics Kissinger method,Coats-Redfern integral method

CORROSION INHIBITION OF X70 STEEL IN SALINE SOLUTION SATURATED WITH CO_2 By.THIOUREA

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Acta Metallurgica Sinica(English Letters) 2008年第1期21卷 65-71页

作者： X. y. He H. y. Deng R. Li X.D. Fei H.y.Wang z. y. Deng College of Chemistry.and Chemical Engineering China West Normal University Nanchong 637002 China

Corrosion monitoring techniques were performed on X7O steel in saline solution saturated with CO2 with and without thiourea additives within the concentration range 5-25 mg/L. It was found that when the concentration of the inhibitors were increased, the inhibitor efficiencies（IE） of thiourea varied with solution temperature and immersion time. The results indicated that thiourea had the highest inhibition efficiency. The potentiondy.amic polariz.tion studies revealed that thiourea are mixed-ty.e inhibitor that mainly.restrains the anodic process.

关键词： Corrosion Inhibition Thiourea XTO steel

Carbon nanotube and conducting poly.er composites for supercapacitors

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Progress in Natural Science:Materials International 2008年第7期18卷 777-788页

作者： Daniel Jewell George z. chen School of Chemical and Environmental and Mining Engineering University of Nottingham University ParkNottingham NG7 2RD UK

Composites of carbon nanotubes and conducting poly.ers can be prepared via chemical sy.thesis, electrochemical deposition on pre- formed carbon nanotube electrodes, or by.electrochemical co-deposition. The composites combine the large pseudocapacitance of the conducting poly.ers with the fast charging/discharging double-lay.r capacitance and excellent mechanical properties of the carbon nanotubes. The electrochemically.co-deposited composites are the most homogeneous and show an unusual interaction between the poly.er and nanotubes, giving rise to a strengthened electron delocalisation and conjugation along the poly.er chains. As a result they.exhibit excellent electrochemical charge storage properties and fast charge/discharge switching, making them promising electrode mate- rials for high power supercapacitors.

关键词： Supercapacitor Carbon nanotube Conducting poly.er

MODELING OF MICROSTRUCTURAL EVOLUTION IN MICROALLOy.D STEEL DURING HOT FORGING PROCESS

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Acta Metallurgica Sinica(English Letters) 2006年第4期19卷 279-286页

作者： J. Wang J. chen z. z.ao X.y. Ruan National Die ＆. Mold CAD Engineering Research Center Shanghai Jiaotong University Shanghai 200030 China

The microstractural evolution of microalloy.d steel during hot forging process was investigated using phy.ical simulation experiments. The dy.amic recry.talliz.d fraction was described by.modify.ng Avrami＇s equation, the parameters of which were determined by.single hit compression tests. Double hit compression tests were performed to model the equation describing the static recry.talliz.d fraction, and the obtained predicted values were in good agreement with the measured values. Austenitic grain growth was modeled as： Dinc^5 = D0^5 ＋ 1.6 × 10^32t·exp （ -716870/RT ） using isothermal tests. Furthermore, an equation describing the dy.amic recry.talliz.d grain siz. was given as Ddy.=3771·z.-0.2. The models of microstructural evolution could be applied to the numerical simulation of hot forging.

关键词： microalloy.d forging steel flow stress recry.talliz.d fraction grain siz.

Temporal and Spatial Requirement of EMF1 Activity.for Arabidopsis Vegetative and Reproductive Development

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Molecular Plant 2009年第4期2卷 643-653页

作者： Rosario Sanchez.Minjung y. Kim My.iam Calonje y.ng-Hwan Moon z. Renee Sung Department of Plant and Microbial Biology University of California Berkeley CA 94720 USA Present address: Heidelberg Institute for Plant Science Biodiversity and Plant Systematics Heidelberg University 69120 Heidelberg Germany Present address: Department of Molecular Biology Pusan National University 30 Jangjeon-dong Geumjeong-gu Busan 609-735 Korea

EMBRy.NIC FLOWER （EMF） genes are required to maintain vegetative development via repression of flower homeotic genes in Arabidopsis. Removal of EMF gene function caused plants to flower upon germination, producing abnormal and sterile flowers. The pleiotropic effect of ernfl mutation suggests its requirement for gene programs involved in diverse developmental processes. Transgenic plants harboring EMF1 promoter：：glucuronidase （GUS） reporter gene were generated to investigate the temporal and spatial expression pattern of EMF1. These plants display.d differential GUS activity.in vegetative and flower tissues, consistent with the role of EMF1 in regulating multiple gene programs. EMFI：：GUS expression pattern in emf mutants suggests organ-specific auto-regulation. Sense- and antisense （as） EMF1 cDNA were expressed under the control of stage- and tissue-specific promoters in transgenic plants. Characteriz.tion of these transgenic plants showed that EMF1 activity.is required in meristematic as well as differentiating tissues to rescue emf mutant phenoty.e. Temporal removal or reduction of EMF1 activity.in the embry. or shoot apex of wild-ty.e seedlings was sufficient to cause early.flowering and terminal flower formation in adult plants. Such reproductive cell memory.is reflected in the flower MADS-box gene activity.expressed prior to flowering in these early.flowering plants. However, temporal removal of EMF1 activity.in flower meristem did not affect flower development. Our results are consistent with EMF1＇s primary.role in repressing flowering in order to allow for vegetative growth.

关键词： EMF1 stage-specific promoter early.flowering reproductive cell memory vegetative/reproductive development repression of flower MADS-box genes.

A betatron tune measurement sy.tem based on bunch-by.bunch transverse feedback at the Duke storage ring

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Chinese Phy.ics C 2013年第7期37卷 76-82页

作者：徐卫 W. z. Wu 李京祎何多慧 y. K. Wu National Sy.chrotron Radiation Laboratory.(NSRL) University of Science and Technology of China FEL Laboratory TUNL and Department of Physics Duke University

To combat electron beam instabilities, a digital bunch-by.bunch transverse feedback （TFB） sy.tem has been developed for the Duke storage ring. While it is capable of suppressing transverse beam instabilities for multibunch operation, the TFB sy.tem has not been needed for ty.ical operation of the Duke storage ring. To explore the great potential of this sy.tem, we have developed beam diagnostic techniques using the TFB, in particular, the TFB based tune measurement techniques. The tune measurement technique allows us to conduct fast chromaticity.measurements, compared with the existing chromaticity.measurement sy.tem using a network analy.0}r. This new tune measurement sy.tem also enables us to measure the bunch tune for multibunch operation of the Duke storage ring. With the TFB based tune measurement sy.tem, we have studied the tune stability.of the electron beam in the Duke storage ring. This tune sy.tem has also been used to calibrate the tune knob for the Duke storage ring.

关键词： transverse feedback tune chromaticity

FATIGUE CRACK GROWTH FEATURE OF Fe-Cr-Ni MATRIX COMPOSITE REINFORCED By.TITANIUM CARBIDE PARTICULATE AT 1023K

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Acta Metallurgica Sinica(English Letters) 1999年第6期12卷 0-0,0-0+0-0页

作者： z. F. Wan X.D. Hui G.Q. y.an y. S. y.ng X.C chen Shandong University.of Technology Jinan 250061 China Institute of Metal Research The Chinese Academy of Sciences Shenyang 110015 China Institute of Phy.ics The Chinese Academy of Sciences Beijing 100080 China

The initiation and propagation of the short fatigue crack in a 10vol% titanium carbide particulate reichreed cast Fe-26Cr-14Ni mathe coopsite at 1023K were *** is shown that the titanium carbide particulate may.hinder the crack propagation and fatigue fracture of the composite. The relationships between fatigue crack propagation rate and stress intensity.factor are da/dN=4.2×10-c(△K)4 for the matrix alloy.and da/dN=1.4×10-19(△K)c for the composite. The fatigue thresholds of the composite and mathe alloy.are 78 and 3.2MPa.m1/2, respectively. Microcracks initiate at the intedece between titanium carbide particulate and austenite and then propagate in carkide particles. The fracture sudece of the composite shows a distinct transition from wavy.and serated cleavage near the threshold regime to striation-ty.e splitting in the stable fatigue crack propagation stage and to a veined morphology.characteristic in unstable rapid region.

关键词： fatigue crack initiation and propagation Fe-Cr-Ni matrix composite titanium carbide particulate

Forging strength-ductility.unity.in a high entropy.steel

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Journal of Materials Science & Technology 2022年第18期113卷 158-165页

作者： S.J.Tsianikas y.chen J.Jeong S.z.ang z.Xie School of Mechanical Engineering The University of AdelaideSA 5005Australia Centre for Advanced Thin Film Materials and Devices Faculty of Materials and EnergySouthwest UniversityChongqing 400715China Max-Planck-Institut für Eisenforschung Max-Planck-Straße 1Düsseldorf 40237Germany

Fe_(72.4)Co_(13.9)Cr_(10.4)Mn_(2.7)B_(0.34)high entropy.steel was prepared by.magnetron *** alloy.exhibits a high y.eld strength of 2.92±0.36 GPa while achieving appreciable plasticity.of 13.7±1.9%at the ultimate compressive strength(3.37±0.36 GPa).The distribution of iron and chromium shows an un-usual,characteristic spinodal-like pattern at the nanometer scale,where compositions of Fe and Cr show strong anticorrelation and vary.by.as much as 20 at.%.The high strength is largely.attributable to the compositional modulations,combined with fine grains with body.centered cubic(BCC)cry.tal structure,as well as grain boundary.segregation of interstitial *** impressive plasticity.is accommodated by.the formation and operation of multiplanar,multicharacter dislocation slips,mediated by.coherent in-terfaces,and controlled by.shear *** excellent strength-ductility.combination is thus enabled by.a range of distinctive strengthening mechanisms,rendering the new alloy.a potential candidate for safety.critical,load-bearing structural applications.

关键词： Deformation mechanisms Micromechanical testing Compositional fluctuations Body.centered cubic High entropy.steel