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  • 综述 进展
    Zhen-Feng ZHUSha Cheng;
    . 2013, 44(21): 0-0.
    Graphene has attracted tremendous attention from researchers due to its excellent electrical, thermal, mechanical properties, as well as high optical transparency and large specific surface area, etc. Especially in 2004, stable graphene was successfully gained, it leads to a high tide for the research. To get the graphene which is low cost, large area, high quality and can be applied to practical production is the aim of the researchers. This paper reviews some modified or new preparation methods of the graphene and its potential applications in recent years, from which we can see the huge development potential of the graphene.
  • 研究与开发
    ZHANG Li Yuan;;;
    . 2010, 41(12): 0-0.
    Ag-doped TiO2 was prepared by sol-gel process. The characteristics of TiO2 powder were investigated by SEM、XPS、XRD、UV-Vis. The results indicated that the diameter of undoped TiO2 particles was 80~100 nm and that of Ag-doped TiO2 particles was 40~50 nm, Ag was successfully doped into crystal lattice and the content of Ag was 0.67at%. The Crystal forms of Ag-doped and undoped TiO2 were almost the same after annealing at 400℃. However, transform from anatase to rutile could be restrainted after annealing at 600℃. The absorption profile of TiO2 was shifted to longer wavelength by doping.The optimal doping quantity was 0.5% and the optimal annealing temperature was 600℃. Methyl orange was used as the degradable agent in photocatalytic experiment. The results indicated that methyl orange could be degraded 97.9 % by Ag-doped TiO2 under the optimal conditions after 120 minutes.
  • 综述 进展
    ;;;zhang dong
    . 2013, 44(21): 0-0.
    The thickness of the single layer graphene is 0.335 nm, with the fluctuation of 1nm in vertical direction. The layer and structure of graphene depend on the preparation process, to prepare high quality graphene, one of the key steps is how to confirm the layer number and structure of graphene effectively. This paper introduced several main methods used to characterize graphene including the optical microscope, scanning electron microscope (SEM), transmission electron microscope (TEM), atomic force microscope (AFM), Raman spectrum (Raman), infrared spectrum (IR), X-ray photoelectron spectroscopy (XPS) and ultraviolet-visible spectra (UV - Vis) .
  • 研究与开发
    WANG Yan;;;
    . 2011, 42(04): 0-0.
    LiFePO4 is considered the first choice for the next generation cathode materials of lithium-ion battery because of its advantages, such as abundant resources, high capacity, medium voltage, excellent cycling performance and electrochemical properties stability. In this paper, olivine-type crystal structure and the synthesis process of LiFePO4 is to be introduced, Modification of its shortcomings is discussed,and its developing trend is also prospected.
  • 综述
    . 2010, 41(S1): 0-0.
    Abstract:This paper begins with the piezoelectric effect and introduces the classification and structure of piezoelectric materials.Considering the application of different piezoelectric materials in the production practice,preparative techniques of piezoelectric material in the current stage are listed。Research actuality of piezoelectric materials is summaried. application and development of the piezoelectric materials in various fields are also introduced systematically.
  • 研究与开发
    WU Jing;ZHOU Wenfang;GAO Pan
    . 2010, 41(04): 562-565.
    Abstract: The nano-TiO2 doped with Pr was prepared by sol-gel method. The samples were analyzed by X-ray diffraction(XRD), FT-IR, UV-Vis, TEM, et al. The photocatalytic activity of Pr-TiO2 was investigated at different doping dosage and different calcinated temperatures by measuring the degradation rate of methyl blue(MB) under the irradiation of fluorescent lamp. The results show that crystal phase of Pr-TiO2 sample is a mixed phase of anatase and rutile. The existence of the doped element Pr increase the photocatalytic activity of TiO2. Meanwhile, the photocatalytic activity of the sample at the calcinated temperature of 500℃, Pr:TiO2 =1:300(molar ratio) and pH=2.5 is the best, and it is obvious higher than that of P25.
  • 研究与开发
    ;Qinyan Yue;;;;
    . 2010, 41(06): 0-0.
    The purpose of this study was using dehydrated sewage sludge, fly ash and clay to prepare lightweight ceramics for fillers. The Ultra-lightweight sludge ceramics (LWSC) were experimentally produced with various mass ratios of sludge, clay and fly ash, and then the suitable mass ratios and the suitable process were determined. The Optimum conditions (additions of clay, sludge and fly ash, preheating temperature and time, sintering temperature and time) which used for fillers were selected by orthogonal experiment L18 (37). Properties (physical properties, microstructure and toxic metal leaching) were tested at last. The results shows that the LWSC used for fillers are light (bulk density is 365kg/m-3), high hydroscopic (water absorption is 49.46%), nontoxic(contents of toxic metal leaching test are all below the detection limit)and porous(more pores than the commercial lightweight ceramics).
  • 研究·开发
    FU Lu-jun;DONG Fa-qin;YANG Yu-shan;HE Ping
    . 2013, 44(04): 548-551.
    In order to prepare shape-stabilized phase change energy storage materials which were applied to control temperature of building materials, capric acid was mixed separately with lauric acid, myristic acid and palmitic acid to prepare binary fatty acid eutectic mixtures. The phase transition temperature of binary fatty acid and its corresponding mixing proportion are calculated based on Schroder equation. Shape-stabilized CA-MA/SiO2 composite phase change materials were prepared using sol-gel methods. The structure, microstructure, thermal properties and thermal stability of composite materials were characterized by infrared spectroscope, scanning electronic microscope, differential scanning calorimeter and thermogravimetric analysis apparatus, respectively. It was shown that as prepared binary fatty acid had an appropriate temperature and latent heat which can be applied in building field. The CA-MA was well dispersed in the porous network of SiO2, and there was no chemical interaction between CA-MA and SiO2. The melting temperature and melting latent heat of the composite phase change materials is 20.96 ℃ and 70.17 J/g, respectively, and composite materials have good thermal stability. So the composite materials were considered as an effective latent heat thermal energy storage materials in building energy conservation.
  • 工艺 ·技术
    LIU Shuan;SUN Hu-yuan;SUN Li-juan
    . 2013, 44(06): 858-861.
    the effects of pH values and temperature on the electrochemical corrosion behavior of galvanized steel in simulated rust layer (SRL) solution were studied by using the polarization curves, electrochemical impedance spectroscopy and scanning electron microscopy (SEM). The results indicated that galvanized steel was in the passive state in high alkaline SRL solution, the corrosion resistance of galvanized steel increased with the increase of pH values of SRL solution. The corrosion rate of galvanized steel was almost invariant in temperature range from 0 to 40℃. However, when the temperature raised to 60℃, the corrosion rate of galvanized steel increased rapidly.
  • 研究与开发
    . 2011, 42(06): 0-0.
    In this paper,The impact of temperature on magnetorheological fluid responsive particles,carrier liquid and additives is studied. The magnetorheological fluid with Excellent temperature performance is prepared.The magnetorheological fluid viscosity-temperature relationship is analyzed. At the same time,the performance of magnetorheological fluid shock absorber at different temperature is discussed.
  • 综述 进展
    Tao LI;;;;
    . 2013, 44(20): 2913-2918.
    Due to the excellent mechanical compatibility, biocompatibility and biodegradability, magnesium and its alloys are becoming the research focus of a new generation of biomedical degradable metallic implant materials. However, the rapid degradation rate of magnesium and its alloys puts serious obstacles in the way of their clinical applications. It is highly urgent to develop magnesium alloys with high strength, high toughness, high corrosion resistance, and controllable degradation behavior. The latest research progress in degradable biomedical magnesium alloys is reviewed. The advantages and disadvantages, current products, degradation mechanism and corrosion behavior, and corrosion resistance research are presented in detail for magnesium and its alloys as biomedical materials. The problems in the research and future development directions are also pointed out.
  • 研究与开发
    . 2011, 42(04): 0-0.
    Super absorbent resin (SAR) was prepared via aqueous solution polymerization with acrylic monomer. The influences of functional groups in resin chains, reaction temperature and reaction pH on water absorbency of super absorbent resin were investigated. Results show that methyl have negative effect on water absorbency. Hydroxyl is a group for the well-being of water absorbency. The contribution of ester on water absorbency is poorer than carboxylic. The water absorbency of resin is decrease along with the increase of chain length of ester. When reaction temperature and reaction pH are rising, the water absorbency of resin is increased and then decreased.
  • 研究·开发
    GAO Chun-tao;CAI Yi-bing;WANG Qing-qing;WEI Qu-fu;XU Yang
    . 2013, 44(02): 240-243.
    Combined with sol-gel technique and electrospinning methods, the electrospun precursor solution was prepared through mixing the PVP and tetrabutyl titanate; and then PVP/TiO2 composite nanofibers were prepared by electrospinning. The TiO2 nanofibers as photo catalysis were prepared by calcinating PVP/TiO2 composite nanofibers at 500oC. The photocatalytic degradation properties of TiO2 nanofibers were studied through taking different kinds of dyes (Cationic Brilliant Red 5GN, Weak Acid Yellow GN、Remazol Blue RR) as organic pollutant model. The structural morphology of the PVP/TiO2 andTiO2 nanofibers was characterized by SEM. The composition and crystal structure of TiO2 nanofibers were analyzed by FT-IR spectra and XRD. The experimental results indicated that TiO2 nanofibers processed desired morphology, anatase-TiO2 crystal structure and good photocatalytic degradation properties on different dyes.
  • 研究与开发
    YUAN Jin-Hai
    . 2011, 42(06): 0-0.
    The modification of sodium bentonite with EDTA by microwave were studied, based on the removal rate of Pb2+ as the reference index. The best modification conditions: bentonite 3g, EDTA 1g, pH value to 8 ,microwave power 500W, reaction temperature 35 ℃, microwave reaction 5min;Optimum adsorption conditions: adjust pH value to 5.83, adding 0.4 g bentonite, oscillation temperature 30 ℃, batch adsorption 40 minutes. The results showed that the Pb2+ removal rate may reach to 94% using the modified bentonite as adsorbent, the saturated adsorption weight is 29. 67mg/g.the max adsorption ability of modified bentonite is twice sodium bentonite in weight. XRD shown that the dimension of the pillared interlayer was increased from 1.51nm to 1.65nm,IR spectrum certified that appeared C-C adsorb peak, element analysis result shown that the organ C,N,H increased than the bentonite.
  • 研究与开发
    ;
    . 2010, 41(09): 0-0.
    In order to increase the loading dose of hydrophobic drugs on alginate and control the drug release rate, sodium alginate was hydrophobically modified with n-octylamine through the reaction of carbodiimide. The modified alginate was characterized with FTIR and 1HNMR. The modified alginate was made into microsphere beads in aqueous solution of 3wt% calcium chloride. A hydrophobic drug of ibuprofen was loaded on the modified alginate for the in vitro investigation on the drug-controlled release. The results indicated that the drug-loaded dose was obviously increased and the release rate could be well controlled.
  • 研究·开发
    ZHAO Yi-ping;YAN Jia-jian;CHEN Ding-meng;CHEN Li;DONG Zhi-zhi;FU Wei-gui
    . 2013, 44(05): 697-699.
    Halogen-free flame retardant polyurethane foams (PUFs) were prepared by filling one or two kinds of N,N'-bis(2-thio-5,5-dimethyl-1,3,2-dioxaphosphorinane) ethane(DDPSN), melamine (MA) and ammonium polyphosphate (APP). The results of limiting oxygen index (LOI) revealed that in the single component flame retardants DDPSN had the best flame retardancy for PUFs. In the two compound flame retardants, DDPSN/MA and DDPSN/APP had excellent synergistic effect, especially DDPSN/APP. The results of tensile test indicated that APP had the best reinforcing effect for PUFs. In the two component flame retardants, DDPSN/APP was the best.
  • 研究与开发
    ZHENG Meng;ZHAO Yutao;CHEN Dengbin
    . 2011, 42(S3): 748-750.
    In-situ (Al2O3)np/Al composite was synthesized by the direct melt reaction (DMR) technique with Na2B4O7?10H2O and K2ZrF6 powders using a new reaction system. Microstructures and phases of the composite were analyzed by SEM, XRD and TEM. Results indicate that plenty of nano γ-Al2O3 particulates, whose sizes are 20~100nm, have been obtained and distributed uniformly in the aluminum matrix. The formation mechanism of nano-size Al2O3 particle is Reaction-Solution-Precipitation.The coherent relationship with γ-Al2O3(040)∥Al(200) exist in the interfaces between the Al matrix and the γ-Al2O3 particles, and no resultant production is found along these interfaces. Since the formation of nano Al2O3 particles, there are large amount of high density dislocations in the composite, which make it strengthening remarkably.
  • 研究与开发
    . 2011, 42(07): 1342-1345.
    Abstract: Taking industrial waste fly ash as main raw materials, it detailed the process of sintering CaO-Al2O3-SiO2 system fly ash glass-ceramics. Conducted a study on fly ash glass-ceramics through the use of differential thermal analysis (DTA), X-ray diffraction (XRD) and techniques and so on, and tested the physical and chemical and mechanical properties of fly ash glass-ceramics. Experimentally analyzed the effect of the dosage of binder and pressure in the molding process of glass-ceramic samples. Test results showed that: the main crystal phase of fly ash glass-ceramics was wollastonite, vice crystal phase was anorthite; it would obtain optimal samples by forming glass-cerammics in binder dosage was 20%, and under the pressure of 20Mpa.
  • 工艺 ·技术
    CHEN Ya-fei;YANG Wen-bin;WEI Xia;FAN Jing-hui;ZHANG Kai;DONG Fa-qin
    . 2013, 44(05): 748-751.
    A kind of thermally conductive and electrically insulating composites were obtained from mixture of flake graphite, silicon carbide whiskers, alumina particles and polycaprolactam (PA6) by melt blending using a twin-screw extruder, and then samples were prepared by compression molding. Morphology, thermally conductive property, insulating property and thermal stability of composites were characterized by scanning electron microscopy (SEM), thermal conductivity analysis instrument, high resistance micro-current tester and thermal gravimetric analysis (TG). The results indicated that the ternary fillers were dispersed homogeneously and formed thermally conductive networks in polymeric matrix. With the increasing of the hybrid fillers content, the thermal conductivity and the initial decomposition temperature of composites were increased gradually, but the surface resistivity and the volume resistivity were declined. When the filler content was up to 50wt%, the thermal conductivity, the volume resistivity and the initial decomposition temperature were up to 1.407W/(m?K), 1.03x1011Ω?cm and 344℃, respectively.
  • 综述 进展
    Xia SHEN
    . 2014, 45(05): 0-0.
    The types, characteristics and the existing compounds in magnesium of rare earth elements were discussed. The influence of rare earth elements on purification and grain refinement of magesium alloys were summarized. The effects of rare earth elements on the mechanical properties of magnesium alloys were analysised by Mg-Al-RE, Mg-Zn-RE, Mg-Li-RE alloys series. The research and exploitation situations of mechanical property of Mg-RE alloys was reviewed. Finally, applications of rare earth elements in magnesium alloys were prospected.
  • 研究与开发
    Xiao-Min Liu;Xian-Lun Deng;Guo-Dong Wang
    . 2012, 43(04): 476-479.
    In this paper,activated carbon was prepared from sawdust,using chemical activation(the activation reagent was phosphoric acid).The effects of the adsorption time,the n-butane flow and the temperature on the adsorption of the n-butane were investigated.The kinetics of adsorption at different temperature were studied as well.The experimental results show that the adsorption of the butane is a rapid physical process with adsorption and desorption coexisting.The flow of n-butane significantly influence adsorption rate and adsorption time,but it has little influence on the amount of n-butane adsorbed at equilibrium(qe).The amount of n-butane adsorbed at equilibrium decreases with the increase of temperature.It indicaties activated carbon adsorption of n-butane is a exothermic reaction.It is also found that the sorption kinetics are satisfied with Bangham equation with R2 > 0.99. The value of qe obtained through Bangham equation is very close to the value of experimental data.Therefore the ideal adsorption rate equation can be obtained by data fitting.
  • 研究与开发
    Fu-de Lu;De Gao
    . 2012, 43(01): 39-41.
    Basing on universal testing machine and drop testing machine, the cushion theoretical model of C-flute corrugated paperboard is established and the parameters of the model are identified by using least square method. The given example of cushion packaging dynamic shows the constitutive model can be used to packaging design, and this method is better than the maximum acceleration-static stress curves that need more test and data in designing cushioning packaging.
  • 研究与开发
    Wei-jiu HUANG ;
    . 2012, 43(24): 0-0.
    The graphene was prepared by reduction process of graphite oxide, and the polyimide (PI) composites reinforced by graphene were prepared by solution blending method. The mechanical and tribological properties of PI composites reinforced by graphene were evaluated, and the wear mechanism was also analyzed. The results show that the tensile strength, elongation at break and hardness of the composites increased and then decreased with the increasing content of graphene, while the impact strength increased and then decreased, and rose again. The polyimide composites filled with 1 wt.% graphene exhibited the ultimate value of the tensile strength and elongation at break, the two values had been increased by 149% and 652%, compared with the pure polyimide, respectively. The addition of graphene may effectively enhance the tribological properties of composites. Along with the graphene content increased, the wear rate of the composites declined and then rose, while the friction coefficient significantly reduce at first and then gently decrease. The wear rates of the composites display the gentle decline trend with an increase of load and ascendant trend with increasing sliding speed. The main wear mechanism of the composites modified by grapheme was adhesive wear.
  • 综述·进展
    CHEN Hai-lu;HU Shu-chun;WANG Nan;LIN Zhi-jian;XIA Gen-pei;LIU Wen-feng;REN Kai-xuan;JI Lei;SHAN Chun-feng
    . 2013, 44(S1): 15-20.
    As the power increases, LED (Light Emitting Diode) devices appear much higher junction temperature. Furthermore, the reliability and working life will both be obviously reduced with the increase of junction temperature. So, heat dissipation technology and materials with high efficiency, low cost and high reliability are very important to design and prepare high-power LED devices. The progress of the heat dissipation technology and materials in the area of high-power LED device is reviewed in this paper from the following three aspects, design method of chip structure, auxiliary heat dissipation technologies and devices, and a series of heat dissipation materials used in the encapsulation area of LED devices.
  • 研究与开发
    Shao-dan Bi;Xiang-Yan An;Ming-Yan Dang
    . 2012, 43(08): 1001-1004.
    Chitosan modified by vanillin(V-CTS) were prepared with microwave radiation method for adsorption of Cd(Ⅱ)ions were investigated. V-CTS was characterized by means of FTIR,SEM and XRD. Results showed that the isothermal adsorption follows the isothermal adsorption model of Freundlich. Enthalpy change at adsorption temperatures in range of 298-318K is 24.2174 kJ/mol,, which suggests that adsorption process is endothermic. The adsorption kinetics followed the mechanism of the pseudo-second-order equation and activity energy is 25.57597 KJ/moL, evidencing chemical sorption as the rate-limiting step of adsorption mechanism and not involving a mass transfer in solution. After 4 times regeneration experiment,the uptake amount of Cd(Ⅱ)ions reduced 18.9%.
  • 研究与开发
    xia qi bin
    . 2012, 43(16): 0-0.
    In this work, deactivation and regeneration of V2O5/TiO2 catalyst for elimination of NO were studied. The spent V2O5/TiO2 catalyst sample was from a domestic power plant, which had been operated for 20,000 hours. The spent V2O5/TiO2 catalyst was characterized by SEM, EDS, XRD and BET techniques to reveal the deactivation mechanism. The regeneration of V2O5/TiO2 catalyst was conducted by washing with aqueous solution of 0.5 mol/L H2SO4 or 0.01 mol/L HF. The results showed that the activity of the spent catalyst dropped greatly in comparison with the fresh catalyst. The reason was that the spent catalyst was heavily covered by ash which blocked the active sites and plugged the pores. After the spent catalyst was washed with aqueous solutions of 0.01mol/L HF, the activity of regenerated catalyst was improved significantly due to effective removal of silicon dioxide covered on the spent catalyst, a main composition of the ash.
  • 研究·开发
    LIU Yu-gui;ZHANG Jin;ZHU Zhong-qi;LIU Qiang;LIU Qing-ju
    . 2013, 44(02): 157-160.
    The acrylic acid and acrylamide (PAA-AM) superabsorbent copolymer was synthesized by inverse-suspension polymerization with cyclohexane as dispersant, Span80 as suspension stabilizer, acrylic acid (AA) and acrylamide (AM) as comonomer, potassium persulfate as initiator, N,N'-methylene-bis-acrylamide as crosslinking agent. The influence of neutralization degree of AA, mass ratio of acrylic acid (AA) to acrylamide (AM), the amount of crosslinking agent and initiator, and reaction temperature on the absorption capability of water and salt solution were investigated. The results show that the water absorbency of the superabsorbent polymer prepared at the optimum condition in deionized water and in 0.9%NaCl solution is about 1282g/g and 109g/g, respectively, and under the same conditions, The sample has more excellent water absorption and salt-resistance, which compares with the similar products of the SNF (French) production.
  • 研究与开发
    zhangping
    . 2010, 41(06): 0-0.
    Abstract:The rheological and magnetic properties, antisedimentation and aggregation stability,friction properties,and temperature stability of several magnetorheolodical fluids are presented. Some contemporary applications with ideal performence and durability are introduced briefly. Key words:magnetorheological fluid; damper; polishing; seal; durability
  • 研究与开发
    ; ;
    . 2011, 42(01): 0-0.
    Carbon microspheres (CMSs) were oxidized by a mixture of concentrated sulfuric and nitric acids. Then oxidized CMSs were modified by 3-methacryloxypropyl trimethoxysilane. The morphologies and microstructures of all samples were characterized by Fourier transformation infra-red spectrometry, field emission scanning electron microscopy, X-ray photoelectron spectroscopy and thermogravimetry. The results indicate that oxygen-containing groups and KH-570 were successfully grafted on the surface of CMSs after oxidation and silanization treatment, which resulted in a much improved dispersion of CMSs in ethanol. This lays an experimental foundation for the further functionalization of CMSs.
  • 研究与开发
    Hong-Song Song;yang cheng;Da-Bo Liu
    . 2012, 43(09): 1185-1188.
    The fully oxidized graphite oxide(GO) was prepared by Staudenmaier method, and single layer of graphene was obtained through the thermal expansion mechanism. The oxide degree and oxygen containing functional groups of graphite oxide had been investigated by FT-IR, TG; the microstructure of natural graphite (NG), GO and graphene had been analysed by SEM and TEM. The graphene/epoxy nanocomposites had been prepared by ultrasonic processing and mixture method. Dielectric results showed graphene could imporve dielectric constant of PVDF,and when the quality ratio of graphene got 0.25%, the permittivity of composite got to 25, which was 4 times of pure epoxy. A novel ideal of graphene’s application in dielectric and preparation high charge storage density capacitor of low cost was expolred.
  • 研究与开发
    DONG Gang;ZHU Zhongqi;LIU Qingju
    . 2011, 42(11): 1989-1992.
    Abstract: The TiO2 photocatalyst samples co-doped with iron and nitrogen were prepared by sol-gel method and microwave chemical method. The samples were analyzed by XRD, FT –IR, UV –Vis, PL et al. The photocatalytic activity of the samples doped with different Fe content and sintered at different temperature were investigated by measuring the methyl blue (MB)degradation rate under the fluorescent lamp irradiation. The results show that Fe-N-TiO2 samples are a mixed phase of anatase and rutile, and the threshold wavelength is red shift about 45nm. The co-doping of iron and nitrogen inhibit the phase transformation from anatase to rutile and the photocatalytic activity is improved. The activity of the sample prepared at 600℃, n Fe): m(TiO2)=1: 200 is the best under fluorescent lamp and is obviously higher than that of Degussa P25.
  • 综述·进展
    QIAO Li-ying;HE Cong;TAN An-qiang;KUANG Xin-liang;GAO Jia-cheng
    . 2013, 44(09): 1217-1220.
    In recent years, the corrosion resistance of magnesium alloys which are regarded as great potential for the development of the green construction materials has become the focus at home and abroad. Nevertheless, as a technology of environmental protection, silane treatment is energy saving, low emission, low cost, and has been gradually applied to the surface corrosion of magnesium alloys. Magnesium alloys surface silanization treating mechanism, preparation method of silane film, influence factors of silane film’s performance, and its modified methods are summarized. Application deficiency of silane treatment for surface corrosion protection of magnesium alloys is discussed, and the prospect of future main research directions are proposed.
  • 研究 开发
    ;
    . 2014, 45(05): 0-0.
    Abstract: Biodegradable materials, polylactic acid and old eucalyptus wood powder are used as raw material to prepare polylactic acid/wood flour composite (WF/PLA), which provide thought for wood plastic composite completely degradation. FT-IR spectrophotometer, scanning electron microscope and simultaneous thermal analyzer were employed to research the interfacial connection property, thermal properties and crystallization property, together with mechanical property was studied of WF/PLA. The results showed that: Alkyl of KH-570 was grafted to the WF surface; The heterogeneous nucleation crystallization and thermostability improved with the increase of filling WF. When content of wood flour was 50%, the maximum tensile strength of the composite is 29.9MPa, which is 10MPa higher than pure polylactic acid; When content of wood flour was 30%, the maximum bending strength of the composite is 43.2MPa, which is 7.3MPa higher than pure polylactic acid.
  • 研究与开发
    ZHANG Chun Yan;Gao Jiao Cheng
    . 2010, 41(06): 0-0.
    Calcium phosphate coatings were deposited on AZ31 magnesium alloys by virtue of electrochemical deposition. The compositions, phase structures and morphologies of the coatings in different deposition time were investigated by means of X-ray diffractometer (XRD), energy dispersive spectroscopy(EDS) and scanning electron microscope (SEM). The potentiodynamic electrochemical technique was employed to study the corrosion behavior of Ca-P coatings on AZ31 magnesium alloys in Hank’s solutions. The results showed that coatings' morphology changed with deposition time in the deposition process in a bath containing Ca(NO3)2 and NH4H2PO4. The coatings were flake–shape crystals composed of Brushite (DCPD, CaHPO4?2H2O). Significant increase in free corrosion potentials and decrease in corrosion current density indicated that the Ca-P coatings improved corrosion resistance of the AZ31 alloy. The morphologies and the degrees of crystallization of the coatings have obvious influence on corrosion property.
  • 研究与开发
    ;
    . 2011, 42(S4): 0-0.
    ABSTRACT: In this article, the stability and viscosity of the Cu-Water nano-fluids, with different mass faction of particles including 0.1%、0.5% and 1%, prepared by the two-step method were investigated and compared with the results derived from classical two-phase mixture models. The result shows that the incorporation of the SDBS dispersant can significantly improves the viscosity of Cu-water nanofluids. Moreover, there is an optimal stability when the mass fraction of Cu particles is the same as the concentration of SDBS dispersant. The viscosity of the nanofluids increases with the increase of the mass fraction of the Cu particles. However, there is a deviation between the experimental data and the calculation from the formula due to the only consideration of the effect of the mass fraction of particles on the viscosity according to the theoretical models.
  • 研究与开发
    . 2010, 41(02): 0-0.
    Abstract: The biodegradable material poly(D,L-lactic acid)-polyethylene glycol(PLEG) was synthesized with stannous octanoate as catalyst via directly melt polycondensation of D,L–racemic lactic acid (D,L–LA) as monomer with PEG–400,600,800,1000 and 2000 at molar ratio n(PEG)/n(D,L–LA)=1/600. The copolymerization reaction was performed at temperature of 170℃, ω(Sn(Oct)2) of 0.8%, and pressure of 0.096 MPa for 8 hours. The PLEGs were characterized by viscosity-average molecular weight, FT–IR, XRD and contact angle testing. The results demonstrate that the contact angle of PLEG–800 was 63°and the maximum Mη of PLEG–800 can reach 48997. Better hydrophilicity and crystallinity can be reached in case of PEG is chosen as 800,compared with poly(D,L-lactic acid).
  • 研究与开发
    Hai-Ting CUI;;
    . 2010, 41(08): 0-0.
    By using Solidification /Melting models of FLUENT software, the process of heat change on two heat storage balls filled with and not filled with metal foam is numerically simulated. Considered the first kind of boundary condition, temperature field is obtained and phase change interface position changed with time is also calculated. The results indicates that the complete melting time filled with metal foam is greatly shorter than that with paraffin only, enhancing the melting rate of heat storage system. The results got here can provide good references for the numerical simulation of phase change problem and the design of phase change energy storage device.
  • 研究与开发
    Wen-Hao WEI
    . 2012, 43(23): 0-0.
    In this paper, we have developed an alkaline barrier slurry for barrier removal applied in copper chemical mechanical planarization(CMP). Firstly, we have studied the characteristics of removal rate and selectivity of Ta/TEOS/Cu under the same process condition. The results indicate that copper has a low removal rate during barrier CMP by using this slurry, it will protect the copper films from directly dissolution, Ta and TEOS has high removal rate selectivity to Cu, thus it may be helpful to modify the dishing and erosion. The pattern wafer results reveal that the alkaline barrier slurry has a strong modify effect on dishing and erosion reduction, and can be useful applied in barrier CMP.
  • 研究与开发
    . 2010, 41(S1): 0-0.
    Zinc oxide nanoparticles were prepared by using hydrothermal synthesis method.The effect of synthesis conditions on the properties of nanometer was studied. ZnO nonoparticles were obtained when using Zn(NO3)2,NaOH and H2O as properties and hydrothermalmedia. The X-ray diffraction(XRD), the electronic resistivity and the photoluminescence spectrum are applied to investigate the optical and electric properties of ZnO. The result indicated that the samples are zincite in structure and show sharp diffraction peak of ZnO at (101);The electronic resistivity decrease with increasing the time and temperature of synthesis. When time of the synthesis was 25h and temperature was 200℃,ZnO was purest and higher emission at 376nm ,500nm-600nm , the particle figure was rods ,and the even diameter of the nanometer-sized rods ZnO was about 30-40 nm and its length was about 300-400 nm analyzed by TEM. The reasons of the above-mentioned phenomena are deeply discussed.
  • 研究 开发
    . 2014, 45(13): 0-0.
    Ni-TiN coatings were successfully prepared by ultrasonic electrodeposition on the surface of mild steel. The coating microstructure, composition and corrosion behavior were investigated by atomic force microscopy, high-resolution transmission electron microscopy, X-ray diffraction, and scanning electron microscope. The results indicate that the grains of Ni-TiN coating are refined with the increase of ultrasonic power. TiN particles are uniformly distributed in Ni-TiN nanocoating, and matrix grain is refined. the average diameter of Ni grains and TiN particles are respectively 80 nm and 30 nm, respectively. In corrosion tests, the corrosion rate of Ni-TiN nanocoating is very small, and it is about 1.9×10-5 kg/(m2?h), and the surface is smoother, there are a few corrosion holes in the coating.