检索结果-南通市图书馆

Effect of Process Factors on Microstructure of Semisolid Continuous Casting Billets

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2000年第4期14卷 242-245页

作者： Shuming Xing, Qijie Zhai, Hanqi Hu ( Department of Mechanical engineering, Tsinghua university, Beijing 100084, china School of Material science and engineering, shanghai university, shanghai 200072, china Material science and engineering School, Univer Department of Mechanical engineering Tsinghua University Beijing 100084 China School of Material science and engineering Shanghai University Shanghai 200072 China Material science and engineering School University of Science and Technology Beijing Beijing 100083 China

Semisolid continuous casting (SSCC) is a new technology to produce billets for semisolid metal forming (SSMF). The effect of process factors, such as pouring temperature, stirring rate, preheating temperature and thermal conductivity of stirring chamber, on the microstructure of SSCC billets was studied by means of the factorial experimental method. The results show that the microstructure of SSCC billets can be controlled by the above-mentioned four process factors. In order to obtain fine and rounded granular grains in an SSCC billet, the pouring temperature, preheating temperature and stirring rate should be kept in a moderate range, and the thermal conductivity of stirring chamber should be high. The regression equations with the process factors connecting the microstructure was also set up based on experimental data.

关键词： semisolid metal continuous casting process factors microstructure Metallurgy

Synthesis and photoluminescence property of red phosphors LiEu_(1-x)Y_x(WO_4)_(0.5)(MoO_4)_(1.5) for white LED

在线全文

学校读者我要写书评

暂无评论

science china(Technological sciences) 2009年第7期52卷 1913-1918页

作者： XIE An, YUAN XiMing, WANG JuanJuan & WANG Feng engineering research center of Nano-Mineral Materials and Application, Ministry of Education, Faculty of Materials science and chemical engineering, china university of Geosciences, Wuhan 430074, china engineering research center of Nano-Mineral Materials and Application Ministry of Education Faculty of Materials Science and Chemical Engineering China University of Geosciences Wuhan China

A series of novel red phosphors LiEu1-xYx(WO4)0.5(MoO4)1.5 (x=0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.8) were synthesized by conventional solid state reaction method with the starting materials: WO3, MoO3, Eu2O3, Li2CO3 and Y2O3. The spectrum and the crystal structure of the phosphors were characterized by F-4500 and XRD respectively. Meanwhile the effects of flux and Y3+ concentration on the crystal structure and luminescent properties of the phosphors were investigated. The results showed that the optimal content of flux (WAlF3/WH3BO3=1/1) was 1 wt% and the optimal doping concentration of Y3+ was 0.5 mol. The emission spectrum showed the most intense peak was located at 615 nm, which corresponds to the 5D0→7F2 transition of Eu3+ and that Eu3+ occupied the lattice site of noncentrosymmetric environment in the scheelite phases. The excitation spectrum displayed that these phosphors could be effectively excited by ultraviolet (UV) (396 nm) and blue (466 nm) light, nicely in correspondence with the widely ap- plied output wavelengths of ultraviolet or blue LED chips. The influence of flux on the luminescent properties of LiEu0.5Y0.5(WO4)0.5(MoO4)1.5 phosphor was analyzed. The XRD spectra indicated that the flux could help to crystallize the phosphor, and no other phases were formed except the tetragonal. When adding flux, the relative intensity of LiEu0.5Y0.5(WO4)0.5(MoO4)1.5 became much stronger and the average particle size of the phosphor decreased.

关键词： red emitting phosphor LiEu1-xYx(WO4)0.5(MoO4)1.5 flux white LED

Effect of electrolytes on electrochemical properties of graphene sheet covered with polypyrrole thin layer

在线全文

学校读者我要写书评

暂无评论

Progress in Natural science:Materials International 2011年第6期21卷 460-466页

作者： Ya-meng CAI~(1,2),Zong-yi QIN~1,Long CHEN~2 1.State Key Laboratory for Modification of chemical Fibers and Polymer Materials, Donghua university,shanghai 201620,china 2.College of Material science and engineering,Donghua university,shanghai 201620,china State Key Laboratory for Modification of chemical Fibers and Polymer Materials Donghua University Shanghai 201620 China College of Material science and engineering Donghua University Shanghai 201620 China

Graphene sheet(GS) was successfully covered with a polypyrrole(PPy) thin layer through in situ chemical oxidative polymerization of pyrrole monomers in aqueous solution by using GS as a support material and ferric trichloride as an *** resulting nanocomposite was studied by field emission scanning electron microscopy(FE-SEM),Fourier transform infrared spectroscopy(FT-IR) and electrical measurements,including cyclic voltammetry(CV),galvanostatic charge/discharge experiment (GCD),and impedance spectroscopy(EIS).It has been found that the nanocomposite exhibited a typically curved and layer-like structure,and conformational change of PPy chains occurred due to the n-n stacking interaction between the graphitic structures in GS and aromatic rings of the PPy *** attention was paid to the effect of electrolytes on electrochemical properties of the nanocomposites,as expected,electrochemical performance was dependent on the nature of the electrolyte,and the neutral electrolytes containing alkali metal ions were found to be very suitable for GS/PPy *** with the pure PPy,the nanocomposite possessed larger specific capacitance and lower internal impedance,indicating that the nanocomposite can be a promising candidate as electrode material for supercapacitors.

关键词： nanocomposites graphene polypyrrole electrochemical property electrolyte

Experimental study on CCl_4/CH)4/O_2/N_2 oxidation

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

science china(Technological sciences) 2010年第4期53卷 1016-1022页

作者： WANG Bo1,2,CHI Yong2,YAN JianHua2 & NI MingJiang2 1 College of Energy and Power engineering,university of shanghai for science and technology,shanghai 200093,china 2 State Key Laboratory of Clean Energy Utilization,Zhejiang university,Hangzhou 310027,china College of Energy and Power engineering University of Shanghai for Science and Technology Shanghai China State Key Laboratory of Clean Energy Utilization Zhejiang University Hangzhou China

Oxidation within the system CCl4/CH4/O2/N2 is studied at atmospheric pressure in a tubular flow reactor to investigate the influence of reaction temperature and chlorine content on chlorinated waste combustion and find incineration process optimization methods for pollution *** reaction temperature varies from 700℃ to 1000℃ and the CCl4/CH4(or Cl/H) mole ratio of the inlet mixture varies from 0.21 to *** profiles are measured with *** is shown that at the same initial CCl4 concentration and reaction temperature adding CH4 favors CCl4 destruction and CO2 *** the destruction and removal efficiency(DRE) of CH4 decreases with lower Cl/H and higher concentrations of toxic products of incomplete combustion such as COCl2 and CH3Cl are formed at the same *** chlorine in the system favors CH4 decomposition,but it also inhibits further oxidation of *** temperature assists in both CCl4 destruction and CH4 conversion,and the concentration of toxic combustion intermediates is *** the temperature is the most effective way to enhance CCl4 *** CO2 concentration increases with temperature.A CO concentration peak is observed around 800℃:with a certain Cl/H,the CO concentration first increases with temperature and then *** effect of increasing CH4 concentration on CCl4 destruction becomes mild above 900℃.Rather,it enhances the interaction between chlorine and carbonaceous radicals,which leads to higher concentration of toxic products.

关键词： hazardous waste destruction and removal efficiency(DRE) oxidation carbon tetrachloride chlorinated compounds methane

Cellulose nanocrystals as green fillers to improve crystallization and hydrophilic property of poly(3-hydroxybutyrate-co-3-hydroxyvalerate)

在线全文

学校读者我要写书评

暂无评论

Progress in Natural science:Materials International 2011年第6期21卷 478-484页

作者： Hou-yong YU~(1,2),Zong-yi QIN~1,Zhe ZHOU~2 1.State Key Laboratory for Modification of chemical Fibers and Polymer Materials, Donghua university,shanghai 201620,china 2.College of Material science and engineering,Donghua university,shanghai 201620,china State Key Laboratory for Modification of chemical Fibers and Polymer Materials Donghua University Shanghai 201620 China College of Material science and engineering Donghua University Shanghai 201620 China

The green nanocomposites of poly(3-hydroxybutyrate-co-3-hydroxyvalerate)(PHBV) with various cellulose nanocrystals (CNCs) contents were prepared by solution casting *** effects of CNCs on the crystallization behavior,spherulitic morphology,crystal structure and hydrophilic property of PHBV were studied by differential scanning calorimeter(DSC),polarized optical microscope(POM),wide-angle X-ray diffraction(WAXD) and static water contact angle *** is found that the CNCs act as an effective nucleation agent for crystallization of PHBV,inducing an increase in the melt crystallization temperature of the nanocomposites.A study of the non-isothermal crystallization kinetics further illustrated that overall crystallization rate of PHBV in the nanocomposites was faster than that of neat PHBV,but exhibited a decrease in the crystallinity and the spherulite size of PHBV. Furthermore,the contact angle decreased from 60.1°for neat PHBV to 32.5°for the nanocomposites with 10%CNCs(mass fraction).

关键词： nanocomposites poly(3-hydroxybutyrate-co-3-hydroxyvalerate) cellulose nanocrystals crystallization behavior hydrophilic property

Generation and Characterization of C305,a Murine Neutralizing scFv Antibody That Can Inhibit BLyS Binding to Its Receptor BCMA

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 Biochimica et Biophysica Sinica 2005年第6期37卷 415-420页

作者： Mei-Yun LIU~(1.2) Wei HAN~(2.3) Yan-Li DING~(2.3) Tian-Hong ZHOU~1 Rui-Yang TIAN~2 Sheng-Li YANG~2 Hui LIU~2 Yi GONG~2 1 College of Life science and technology,Jinan university. Guangzhou 510632, china 2 shanghai research center of Biotechnology.shanghai Institutes for Biological sciences. Chinese Academy of sciences. shanghai 200233,china 3 School of Pharmaceatical engineering, Shenyang Pharmaceutical university. Shenyang 110016. china College of Life science and technology Jinan UniversityGuangzhou 510632 China shanghai research center of Biotechnology Shanghai Institutes for Biological Sciences Chinese Academy of SciencesShanghai 200233 China School of Pharmaceutical engineering Shenyang Pharmaceutical UniversityShenyang 110016 China

B-lymphocyte stimulator(BLyS)is a member of the tumor necrosis factor(TNF)family anda key regulator of B cell *** single-chain fragment variable(scFv)antibody against BLySbinding to its receptor BCMA has the potential to play a prominent role in autoimmune disease *** display scFv library constructed on pⅢ protein of M13 filamentous phage was screened using *** five rounds of panning,their binding activity was characterized by *** sequencingrevealed that at least two different scFv gene fragments(C305 and D416)were *** two differentscFv gene fragments were expressed to obtain the soluble scFv antibodies,then the soluble scFv antibodieswere characterized by means of competitive ELISA and in vitro neutralization *** results indicatedthat C305 is the neutralizing scFv antibody that can inhibit BLyS binding to its receptor BCMA.

关键词： phage display neutralizing scFv antibody BLyS

engineering of drug nanoparticles by HGCP for pharmaceutical applications

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Particuology 2008年第4期6卷 239-251页

作者： Ting-Ting Hua, Jie-Xin Wanga, Zhi-Gang Shena, Jian-Feng Chena,b, a Key Lab for Nanomaterials, Ministry of Education, Beijing university of chemical technology, Beijing 100029, china b research center of Ministry of Education for High Gravity engineering and technology, Beijing university of chemical technology, Beijing 100029, china Key Lab for Nanomaterials Ministry of Education Beijing University of Chemical Technology Beijing 100029 China research center of Ministry of Education for High Gravity engineering and technology Beijing University of Chemical Technology Beijing 100029 China

This paper reviews our work on the fundamental principles of high gravity controlled precipitation (HGCP) technology, and its applications in the production of drug nanoparticles, which was carried out in a rotating packed bed (RPB). Several kinds of drug nanoparticles with narrow particle size distributions (PSDs) were successfully prepared via HGCP, including the 300-nm Cefuroxime Axetil (CFA) particles, 200–400-nm cephradine particles, 500-nm salbutamol sulfate (SS) particles (100 nm in width), and 850-nm beclomethasone dipropionate (BDP) particles, etc. Compared to drugs available in the current market, all the drug nanoparticles produced by HGCP exhibited advantages in both formulation and drug delivery, thus improving the bioavailability of drugs. HGCP is essentially a platform technology for the preparation of poorly water-soluble drug nanoparticles for oral and injection delivery, and of inhalable drugs for pulmonary delivery. Consequently, HGCP offers potential applications in the pharmaceutical industry due to its cost-effectiveness, efficient processing and the ease of scaling-up.

关键词： High gravity controlled precipitation Rotating packed bed Drug nanoparticle Poorly water-soluble drug Inhalable drug

A new method to improve surface morphology of Ni-Fe-Mo-Co alloy electrode and its catalytic activity for HER

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2007年第3期26卷 205-212页

作者： LUO Beiping REN Buye XU You ZHENG Yajie Department of Chemistry and chemical engineering Hunan Institute of Science and Technology Yueyang 414000 China College of Metallurgical science and engineering Central South University Changsha 410083 China research Institute of Materials science South China University of Technology Guangzhou 510640 China

A new pretreatment method has been developed to improve the catalytic activity of the Ni-Fe-Mo-Co alloy electrode for hydrogen evolution reaction （HER）. The procedure involves pre-electrolyzing the Ni-Fe-Mo-Co alloy electrode in 30% KOH solution containing 10% potassium sodium tartrate at 70℃ for 2 h, until some of the Mo and Fe elements are leached out. The surface morphology of the Ni-Fe-Mo-Co alloy demonstrates a unique hive-like structure after the pre- treatment, which has the pore size in a nanometer range （about 50 nm）, a very large real surface area, and good stability. The results of the electrochemical studies show that compared to other similar electrode materials and the treated Ni-Fe-Mo-Co electrode by leaching method, the pre-treated Ni-Fe-Mo-Co electrode has a much lower overpotential and much higher exchange current density for HER. In addition, a long-term continuous electrolysis test with a current interruption shows that the Ni-Fe-Mo-Co alloy has excellent catalytic stability.

关键词： catalytic activity surface treatment Ni-Fe-Mo-Co alloy hydrogen evolution electrodeposition

A two-dimensional study on natural convection and heat transfer in the enclosure with heat transfer and radiation coupled in natural convection

在线全文

学校读者我要写书评

暂无评论

science china(Technological sciences) 2010年第4期53卷 991-999页

作者： ZHAN NaiYan1,2,YANG Mo1 & XU PeiWei2 1 College of Power engineering,university of shanghai for science and technology,Shanghiai 200093,china 2 Department of Environmental engineering,Jilin Architectural and Civil engineering Institute,Changchun 130021,china College of Power engineering University of Shanghai for Science and Technology Shanghiai China Department of Environmental engineering Jilin Architectural and Civil Engineering Institute Changchun China

Numerical investigation using SIMPLE algorithm with QUICK scheme for natural convection and heat transfer in the enclosure bounded by a solid wall and with heat transfer and radiation coupled in natural convection has been *** various parameters are:Rayleigh number(from 103 to 105),dimensionless conductivity of bounding wall(from 0 to 100),dimensionless wall thickness(from 0 to 0.6) and radiation emissivity of all surfaces(from 0 to 1).The results suggest that flow and heat transfer are influenced by *** is a dominant action on flow and heat *** increase of the thermal conductivity of wall,flow and heat transfer turn *** temperature distribution changes *** the thermal conductivity of wall is over a certain critical number,the increasing trend of flow and heat transfer may *** increase of enclosure wall thickness,flow and heat transfer turn *** the enclosure wall thickness is over a certain critical number,the flow and heat transfer will turn slow.

关键词： conduction natural convection radiation couple numerical simulation