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Influence of silicon on the microstructures, mechanical properties and stretch-flangeability of dual phase steels

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International Journal of minerals,metallurgy and materials 2014年第8期21卷 755-765页

作者： Le-yu Zhou Dan Zhang ya-zheng Liu School of materials Science and Engineering University of Science and Technology Beijing

Uniaxial tension tests and hole-expansion tests were carried out to determine the influence of silicon on the microstructures, mechanical properties, and stretch-flangeability of conventional dual-phase steels. Compared to 0.03wt% silicon, the addition of 1.08wt% silicon induced the formation of finer ferrite grains （6.8μm ） and a higher carbon content of martensite （Cm≈ 0.32wt%）. AS the silicon level increased, the initial strain-hardening rate （n value） and the uniform elongation increased, whereas the yield strength, yield ratio, and stretch-flangeability decreased. The microstructures were observed after hole-expansion tests. The results showed that low carbon content martensite （Cm ≈ 0.19wt%） can easily deform in coordination with ferrite. The relationship between the mechanical properties and stretch-flangeability indicated that the steel with large post-uniform elongation has good stretch-flangeability due to a closer plastic incom- patibility of the ferrite and martensite phases, which can effectively delay the production and decohesion of microvoids.

关键词： dual-phase steel silicon content mechanical properties microstructure strain hardening

Syntheses,Structures,and Luminescent Properties of New Zn~Ⅱ-Y~Ⅲ and Zn~Ⅱ-Ln~Ⅲ Schiff Base Complexes

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Chinese Journal of Structural Chemistry 2015年第8期34卷 1273-1280页

作者： HU Jin-Fa QIN ya-Ru LI Yu LIU Wei WANG Yong LI ya-Hong College of Chemistry Chemical Engineering and Materials ScienceSoochow University

Eight new ZnⅡ-yⅢ and ZnⅡ-LnⅢ heterometallic Schiff base complexes： mZnL2（NO3）3 （m = Y （1）, La （2）, Pr （3）, Nd （4）, Eu （5）, Gd （6）, Dy （7）, Er （8）; L = 2-（（（2- （imidazo[1,5-a]pyridin-3-yl）phenyl）imino）methyl）-6-methoxyphenol）, have been rationally synthesized under solvothermal conditions and characterized by IR, elemental analyses （EA）, single-crystal X-ray diffraction, and powder XRD. Furthermore, luminescence in the visible region for solids 1-8 suggested zine/ligand-centered emission at room temperature.

关键词： heterometallic complex, crystal structure, luminescence

Effect of purification pretreatment on the recovery of magnetite from waste ferrous sulfate

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International Journal of minerals,metallurgy and materials 2016年第8期23卷 891-897页

作者： Wang Yu Ying-lin Peng ya-jie Zheng School of metallurgy and Environment Central South University School of Chemistry and Environmental Engineering Hunan City University

The present study was conducted to elucidate the influence of impurities in waste ferrous sulfate on its recovery of magnetite. Ferrous sulfate solution was purified by the addition of Na OH solution to precipitate impurities, and magnetite was recovered from ferrous sulfate solution without and with purification pretreatment. Calcium hydroxide was added to the solution of ferrous sulfate as a precipitator. A mixed product of magnetite and gypsum was subsequently obtained by air oxidation and heating. Wet-milling was performed prior to magnetic separation to recover magnetite from the mixed products. The results show that with the purification pretreatment, the grade of iron in magnetite concentrate increased from 62.05% to 65.58% and the recovery rate of iron decreased from 85.35% to 80.35%. The purification pretreatment reduced the conglutination between magnetite and gypsum, which favors their subsequent magnetic separation. In summary, a higher-grade magnetite with a better crystallinity and a larger particle size of 2.35 μm was obtained with the purification pretreatment.

关键词： ferrous sulfate titanium dioxide purification magnetite magnetic separation

Characteristics of the transient thermal load and deformation of the evacuated receiver in solar parabolic trough collector

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Science China(Technological Sciences) 2020年第7期63卷 1188-1201页

作者： LI Lu YU HuaJie LI YinShi HE ya-Ling Key Laboratory of Thermo-Fluid Science and Engineering of mOE School of Energy and Power EngineeringXi’an Jiaotong UniversityXi'an 710049China

As a core element in solar parabolic trough collector, the evaluated receiver often runs under severe thermal conditions. Worse still, the transient thermal load is more likely to cause structural deformation and damage. This work develops an efficient transient multi-level multi-dimensional(m2) analysis method to address photo-thermal-elastic problems, thereby estimating transient thermal load and deformation for the receiver:(i) one-dimensional(1-D) thermo-hydraulic model is adopted to determine the transient thermo-hydraulic state,(ii) 3-D finite volume method(FVm) model for the receiver tube is established to obtain the real-time temperature distribution,(iii) 3-D finite element method(FEm) model is employed to make thermoelastic analysis. Based on this m2 method, the typical transient cases are conducted in cold-start, disturbed-operation and regulatedprocess. Three indicators(average temperature of the wall(ATW), radial temperature difference(RTD), circumferential temperature difference(CTD)) are defined for overall analysis of the receiver thermal load. It is found that in the transient process,receivers face response delay and endure significant thermal load fluctuation. The response time for a single HCE(heat collecting element) under lower mass flow rate(1.5 kg s-1) could sustain 280 s. During the cold-start stage(DNI=200 W m-2 to 800 W m-2), the maximum value of CTD in receiver is as high as 11.67℃, corresponding to a maximum deflection of 1.05 *** the mass flow rate decreases sharply by 80%, the CTD reaches 33.04℃, causing a 2.06-cm deflection. It should be pointed out that in the cold-start stage and the lower mass flow rate operation for solar parabolic trough collector, alleviating the transient thermal load and deformation is of importance for safely and efficiently running evaluated receiver.

关键词： solar energy transient thermal load and deformation heat collecting element parabolic trough collector multi-level multi-dimensional analysis method

Preparation of high-purity tellurium powder by hydrometallurgical method

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Rare metals 2014年第4期33卷 479-484页

作者： Yuan Liu ya-Jie Zheng Zhao-ming Sun School of metallurgy and Environment Central South University

This hydrometallurgical method consists of oxidation leaching, sulfide impurities removing, and sulfur dioxide reduction. The crude tellurium powder was treated by H2Oa oxidation for 2.0 h at pH 2.5 when adding 50 ml H2O2 （30 %） per 100 g raw material, a tellurium recover rate around 91% is achieved. The tellurium leaching ratio can reach 98.9 % under 3.75 mol.L-1 NaOH concentration in liquid-solid ratio of 5：1 at 80 ℃ for 1.5 h. The overall separation of tellurium and other heavy metals is optimum at sulfide dosages of about 1.1 times of the theoretical values. The removal rates of Ag, Ni, Pb, and Cu from the solution are greater than 99.8 %, and As and Se removal rates are 98.6 % and 97.2 %, respectively. Over 99.5 % tellurium can be recovered by SOu reaction when the operation is conducted at 85 ℃ in 6 mol.L-1 HC1 solution. The tellurium powder with size of 〈5 μm and purity of 〉99.999 % is obtained.

关键词： High purity Tellurium powder Hydrometallurgical method

Study of C_(70) Adsorbed on Silver Surface by Surface Enhanced Raman Scattering

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Chinese Physics Letters 1997年第7期14卷 513-516页

作者： HUANG ya-bin mO Yu-jun G.mattei m.Pagnnane XIE Si-shen Department of Physics He’nan UniversityKaifeng 475001 Istituto di mAI CNRC.P.1000016 Monterotondo S.(Rome)Italy Institute of Physics Chinese Academy of SciencesBeijing 100080

Twelve new features from our Raman measurements of C_(70) have been observed by using the silver surface enhanced Raman scattering substrate with very high enhanced factor and highly sensitive Raman *** results and discussion in this letter would make new knowledge to vibration modes of C_(70).The experimental data of the study confirm the validity of Jishi's calculation with a small error.

关键词： set silver letter

Effect of mold electromagnetic stirring on solidification structure and solute segregation in continuous casting bloom

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Journal of Iron and Steel Research International 2022年第1期29卷 124-131页

作者： Dong-bin Jiang Li-feng Zhang ya-dong Wang School of metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China State Key Lab of metastable materials Science and Technology Yanshan UniversityQinhuangdao 066004HebeiChina

The effect of mold electromagnetic stirring(m-EmS)on the solidification structure and solute segregation in the continuous casting bloom of U78CrV steel is *** solute distribution in the macroscale is analyzed using a carbon–sulfur analyzer and that in the microscale is measured with an electron probe *** Image-J software is applied to analyze the number density and area ratio of segregation *** results show that the segregation spots are mainly located in the columnar to equiaxed transition zone and the equiaxed zone,which are enriched with C,Cr,and mn *** the m-EmS applied,the columnar grain inclines to the upstream *** the current intensity increases,the deflecting angle of columnar grain rises,especially with the current intensity larger than 300 ***,the center segregation shows a declining trend and the area fraction of the equiaxed zone rises ***,it is found that the area ratio and number density of segregation spots increase with the higher current intensity of m-EmS.

关键词： Solidification structure macrosegregation mesosegregation Segregation spot mold electromagnetic stirring

QcReads:An Adapter and Quality Trimming Tool for Next-Generation Sequencing Reads

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Journal of Genetics and Genomics 2013年第12期40卷 639-642页

作者： Yunfei ma Haibing Xie Xuman Han David m.Irwin ya-Ping Zhang School of Life Sciences University of Science and Technology of China State Key Laboratory of Genetic Resources and Evolution Kunming Institute of ZoologyChinese Academy of Sciences University of Chinese Academy of Sciences Department of Laboratory medicine and Pathobiology University of Toronto

With the advent of next-generation sequencing （NGS） tech-nologies, it is possible to obtain huge amount of genome or transcriptome sequence with high coverage. NGS technologies are now extensively used in various fields such as genetics （Feuillet et al., 2011; Young et al., 2012; Ling et al., 2013） and clinical medicine （Kwon and Goate, 2000; Pflueger et al., 2011;

关键词： length QcReads

Astrophysical S-factor and reaction rate for 15N(p,γ)16O within the modified potential cluster model

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Chinese Physics C 2024年第4期48卷 130-145页

作者： S.B.Dubovichenko A.S.Tkachenko R.ya.Kezerashvili N.A.Burkova B.m.Yeleusheva Fesenkov Astrophysical Institute 050020 AlmatyKazakhstan New York City College of Technology City University of New YorkBrooklyn11201 New YorkUSA Graduate School and University Center City University of New York10016 New YorkUSA al-Farabi Kazakh National University 050040 AlmatyKazakhstan

We study radiative p^(15)N capture on the ground state of ^(16)O at stellar energies within the framework of a modified potential cluster model(mPCm)with forbidden states,including low-lying *** investigation of the ^(15)N(p,γ0)^(16)O reaction includes the consideration of ^(3)S_(1) resonances due to E1 transitions and the contribution of the ^(3)P_(1) scattering wave in the p+^(15)N channel due to the ^(3)P_(1)→^(3)P_(0)m1 *** calculated the astrophysical low-energy S-factor,and the extrapolated S(0)turned out to be within 34.7−40.4 keV·*** important role of the asymptotic constant(AC)for the ^(15)N(p,γ0)16O process with interfering ^(3)S_(1)(312)and ^(3)S_(1)(962)resonances is elucidated.A comparison of our calculation for the S-factor with existing experimental and theoretical data is addressed,and a reasonable agreement is *** reaction rate is calculated and compared with the existing *** has negligible dependence on the variation of AC but shows a strong impact of the interference of ^(3)S_(1)(312)and ^(3)S_(1)(962)resonances in reference to the CNO Gamow windows,especially at low *** estimate the contribution of cascade transitions to the reaction rate based on the exclusive experimental data from ***.C.85,065810(2012).The reaction rate enhancement due to the cascade transitions is observed from T_(9)>0.3 and reaches the maximum factor~1.3 at T_(9)=*** present the Gamow energy window and a comparison of rates for radiative proton capture reactions ^(12)N(p,γ)^(13)O,^(13)N(p,γ)^(14)O,^(14)N(p,γ)^(15)O,and ^(15)N(p,γ)^(16)O obtained in the framework of the mPCm and provide the temperature windows,prevalence,and significance of each process.

关键词： low and astrophysical energies p^(15)N system thermonuclear reaction rate potential cluster model CNO-cycle