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  • 综述 进展
    ;
    . 2013, 44(24): 0-0.
    Surface modification is one of the core technologies in the field of biomedical materials, its fundamental purpose is to make the surface of the biological material has better biocompatibility. Presently, various surface modification has been developed by different groups, and different methods of surface modification is selected in terms of the application fields and the faced problems of biomaterials, including reducing protein adsorption and coagulation, controlling cell adhesion,growth and differentiation, and improving the mechanical properties, The surface modification technology of cardiovascular biomaterials mainly focus on improving the blood compatibility of the materials and the endothelial cell compatibility, and can be further expanded to tissue engineering and regenerative medicine. In this paper, the research status of cardiovascular biomaterials, the surface biomodification methods and the surface modification technology for different purposes are reviewed, in order to provide important reference for the design and development of a new generation of cardiovascular implantable medical devices.
  • 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.
  • 综述 进展
    ;
    . 2013, 44(24): 0-0.
    The reduction of graphite oxide is the most possible method to achieve mass production of graphene. A number of methods have been developed to exfoliate graphite oxide, and each method has its own advantages and disadvantages. Thermal exfoliation is the most economical way to obtain large quantities of graphene especially functional graphene. The exfoliation mechanism is mainly based on that the sudden expansion gases evolved into the spaces between graphene sheets during the heat-treatment process of graphite oxide. Thermal exfoliation can be realized when the sudden expansion gases pressure overcomed the attractive van der Waals inter-actions between layers. However,different oxidation and reduction processes make the functional graphene with different properties. In this paper, current research is reviewed, the mechanism of the oxidation and thermal exfoliation is discussed, which may contribute us to effectively use the controllable factors to partially control the preparation of functional graphene.
  • 综述 进展
    YI CHEN; ;;;;
    . 2013, 44(17): 0-0.
    This article mainly focuses on the current world-wide technology trend of large area (>1.0x1.0 m2)electrochromic smart glasses as building energy efficient windows. We compared and analyzed different technologies in Europe and the US. The mainstream technology for commercialized EC glasses is: All solid-state electrochromic glasses with inorganic transition metal oxides (WO3) as electrochromic materials, Li+ as conducting ions, inorganic compounds or organic polymers containing Li+as electrolytes. We should speed up the commercialization process of this new technology to meet China's growing demands for building energy efficiency.
  • 研究 开发
    Xin-cai LIU;PAN Jing
    . 2014, 45(04): 0-0.
    In this paper, the compressive deformation behavior, samples surfaces and fracture microstructure characteristics have been reviewed at different temperatures and strain rates for bulk metallic glasses (BMGs). BMGs behave like Inhomogeneous brittle fracture, non-Newtonian fluid and Newtonian fluid mode respectively at reduced compressing temperature tr=T/Tg ranging of 77K/Tg ≤tr
  • 研究 开发
    . 2013, 44(13): 0-0.
    Abstract: A highly symmetric multi-branched compound (new antioxidant) N,N, N ', N '-[ 1,4 phenylenediamine] – propionate [ 1,2,2,6,6 – pentamethyl ] piperidine alcohol ester which has not been reported in the literature , has been synthesized by transesterification using N, N, N 'N'- tetra methyl propionate - 1, 4 -phenylenediamine and 1,2,2,6,6 – pentamethyl-4-ol as starting materials, and tetraisopropyl orthotitanate as catalyst. The structure of the compound was confirmed by 1H-NMR, liquid-mass spectrometry test (LC-MS), infrared spectrum test (FT-IR), and elemental analysis . In order to study the properties of the new antioxidant, the new antioxidant、antioxidant D ( N-phenyl -β- naphthylamine)、light stabilizer GW-622 were added to the natural rubber,and made a kind of different Rubber diaphragms,and the properties of masterbatch thermooxidative, photooxidative were also determined. The results indicated that, the new antioxidant has good properties of masterbatch thermooxidative and photooxidative.
  • 研究 开发
    . 2013, 44(13): 0-0.
    Abstract: Al2O3 and Cr3+-doped Al2O3(0.3wt%,1wt%) thin films have been grown on Si(100) substrates by pulsed laser deposition. The as-prepared films show cubic γ-Al2O3 structure. After vacumm annealing at 800 oC for one hour, the crystallinity of the sample was improved. The annealed film presents the diffraction peaks of α-Al2O3 and γ- Al2O3.The SEM image reveals that crystal grains of the films have an average grain size of 250nm and a morphology of bar. The electron energy spectrum shows that element compositions of thin films are almost the same as the according targets. Compared with Al2O3 powder, the intensity of the luminescence peak at 386nm of Al2O3 thin films greatly enhances. This can be ascribed to an increase of oxygen vacancies in the thin films and the concentration of F2+ color centers caused by double-oxygen-vacancy absorbing electrons accordingly enhances. Compared with Al2O3 thin film, the intensity of the luminescence peak at 332nm and 398nm of the annealed Al2O3 thin films greatly enhances, which can be ascribed to an increase of the concentration of color centers (F+、F). The blue shift from 386nm to 381nm of emission peak of Al2O3 thin film after annealing is mainly attributed to release of the internal stress. The photoluminescence spectra of 1wt% Cr3+-doped Al2O3 thin film show two emission peaks at 694 nm and 646 nm, which are caused by electron transition of Cr3 + ions from to 4A2 and 4T2 to 4A2. Keywords: PLD;Cr3+-dopedAl2O3 film;photoluminescence;annealing
  • 研究与开发
    ;Hai-lei Zhao ;;
    . 2012, 43(23): 0-0.
    Organic pyrolytic carbon-coated artificial graphite anode material with a core-shell structure was prepared via a sol-gel and pyrolysis route. The effects of coating amounts and species of carbon resource on the lattice structure, the particle morphology and the electrochemical performance of the modified artificial graphite were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), constant current charge-discharge and cyclic voltammogram (CV) tests. The electrochemical measurements reveal that the sample coated with 5 wt.% PVDF exhibits a stable specific capacity of 360 mAhg-1, a higher initial coulombic efficiency of 88.5%, excellent rate-capability and good cycling stability. This may be mainly attributed to the complete formation and the proper thickness of amorphous carbon film on the surface of graphite particles. The isotropic structure characteristics of amorphous carbon increase the diffusion channels of lithium ions and thus facilitate the electrode reaction process.
  • 研究 开发
    Yu XIAO;;
    . 2014, 45(04): 0-0.
    The authors have adopted the improved co-solvent method to prepare the large-size thin crystals of semiconducting 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-PEN). The thin crystals show the lateral size as large as a few millimeters and the thickness in a range from 90 nm to 700 nm. Polarized optical microscopy confirms their single crystalline nature and it is found that the size and thickness of the thin crystals increase with the increasing of the solution concentration. X-ray diffraction and SEAD analysis reveals that the crystals exhibit high molecular orientation and high structural ordering. The field effect transistors (FET) based on the TIPS-PEN thin crystals exhibit a high hole mobility of 0.39 cm2V-1s-1, two orders of magnitude larger than those from the cast thin films. The hole mobility is found to increase with decreasing the thickness of the crystals.
  • 研究 开发
    ; ;Zhi-De HU
    . 2014, 45(04): 0-0.
    A novel mineral oil-based magnetorheological fluids was prepared with carbonyl iron powder for magnetic particle and SiO2 particles as thixotropic agent,The effect of particle size of SiO2 on magnetorheology, stability and tribological performance of magnetorheologicalfluids was studied by measuring the zero field viscosity, rheological curve, sedimentation rate, and the friction coefficient et al.. The results indicated that the SiO2 with middle particle size as a thixotropic agent could significantly improve the zero-field viscosity, and field-induced shear stress was enhanced with SiO2 in small particle size. Sedimentation stability was improved significantly with the increase of the particle size of SiO2, but the dispersion performance was poor with larger apparent viscosity of sediment. In addition the magnetorheological fluid showed good anti-friction performance with average SiO2 particle size in 15nm and 100nm.
  • 研究 开发
    Ming GONG
    . 2014, 45(04): 0-0.
    The cell outer membrane mimetic structures of nanoparticles were prepared using methacrylic acid (MA), 2-methacryloyloxyethyl phosphorylcholine (MPC) as monomer, potassium persulfate (KPS) and chitosan by template polymerization. The size distribution and structure properties of nanoparticles were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS) and Zeta potential. The drug release properties of nanoparticles were estimated by doxorubicin in vitro release experiment. That cell outer membrane mimetic structures of nanoparticles may have potential applications in the ?elds of gene therapy and drug delivery. The controlled release properties had been an important academic significance on the study of outer cell membrane structures of nanoparticles.
  • 研究 开发
    Jia-Xing YIN
    . 2013, 44(17): 0-0.
    Fe3O4 nanoparticles were prepared through thermal decomposition method and coated by SiO2 using ethyl orthosilicate,then grafted N-[3-(Trimethoxysilyl)-propyl]- ethylenediamine on the surface to prepare amino-functionalized magnetic nano- composite particles Fe3O4@SiO2-NH2. The sample was characterized by TEM, VSM, XRD, FTIR respectively. The adsorption of Pb2+ from wastewater was also investigated under many different conditions. The results showed that the sample with core-shell structure has uniform size of average 50nm,there are rich amino functional groups on the surface. The result of VSM indicated that the sample was superparamagnetic.The experiments demonstrated the sample have excellent adsorptive capacity of Pb2+,which will be used to deal leaded wastewater as a promising adsorbent.
  • 研究 开发
    Guoqiu He
    . 2014, 45(04): 0-0.
    Effect of the times of thermo-mechanical training on the shape memory of Fe-Mn-Si shape memory alloy was studied in this paper. The results show that with the increase of the number of training, alloy strain recovery rate rises to the highest 1.95% after three training sessions and then begins to decrease. Microstructure analysis showed that the rise of it in the initial stage could be attributed mainly to thermo-mechanical training, inducing martensitic preferred orientation and resulting in a uniform distribution of martensite which is running parallel with each other with few of crossover. While the decrease of the recovery rate is primarily due to the serious dislocation tangle forming inside the alloy matrix, which leads to irreversible plastic deformation.
  • 研究与开发
    ; ;
    . 2012, 43(16): 0-0.
    The Cu/AuSn20/Ni (mass percent) joint was prepared by the reflow bonding process, and the microstructure and shear strength of the Cu/AuSn20/Ni joint were investigated. The results showed that, the solder formed a (Au5Sn+AuSn) eutectic microstructure after reflow at 300℃ for a short time, and the cellular-like (Au,Cu)5Sn intermetallic compound (IMC) was formed at the upper Cu/AuSn20 interface, while the flake-like (Ni,Au)3Sn2 IMC was formed at the lower AuSn20/Ni interface. Upon increasing the reflow time, more and more Cu(Ni) atoms from the subtrates diffused into the solder, resulting the shift of chemical composition of the solder. So that the (Au,Cu)5Sn phase at the upper Cu/AuSn20 interface transformed into the ζ(Cu) solid solution. The (Ni,Au)3Sn2 phase at the lower AuSn20/Ni interface grew gradually to form a continuous IMC layer. The eutectic microstructure in the solder vanished and the final microstructure of Cu/AuSn20/Ni joint was composed of the ζ(Cu) solid solution and (Ni,Au)3Sn2 IMC layer.The shear strength of the Cu/AuSn20/Ni joint increased slightly with the incresing of the reflow time.
  • 研究 开发
    Jun-gang FAN;Wen-Xiu LI
    . 2013, 44(17): 0-0.
    Ag+-modified 13X zeolites were prepared by calcinations and metallic ion exchange in nitrate solution and used for adsorptive desulfurization of fuel. Different metallic ion effect the desulfurization capacity by the order of Ag+>Ni2+>Zn2+>Fe3+, it also conform to Hard-Soft Acid-Base Theory. Calcinations influence the modification through temperature and time, and the optimal conditions are 450 ℃ and 6 hours, respectively. SEM、XRD and BET characterization indicate the modification did not change the framework of porous solid materials. Fix-bed experiments were carried out with thiophene dissolved in n-heptane as model gasoline, and the results illustrate the Ag+-modified 13X zeolites have higher desulfurization capacity than 13X.
  • 研究 开发
    wang bing
    . 2013, 44(13): 0-0.
    Highly ordered TiO2 nanorod arrays were prepared on glass substrate by using hydrothermal method. The characterization of TiO2 nanorod arrays was studied by using scanning electron microscope (SEM) and X-ray diffraction (XRD) analysis. Results showed that TiO2 nanorod arrays had highly crystallized rutile phase, better verticality on the substrate and density arrays when ratio of acid to deionized water was 1.0.
  • 研究 开发
    ;;Hui-hui ZHANG ;
    . 2013, 44(13): 0-0.
    In this paper, different coupling agents were used to modify the luminescent powder and the change of sedimentation properties of luminescent powder in aqueous NMMO solution was compared, and then a suitable titanate coupling agent was chosen to improve the dispersion stability of luminescent powder in NMMO solution. Moreover, the long afterglow luminescent Lyocell fibers were spun by the dry-jet wet spinning process. The results showed that the tensile strength of fibers was improved after the treatment of the coupling agent. With the increase of luminescent powder content, the degree of crystallinity and the thermal property of fibers were decreased slightly, whereas the initial luminescent intensity was improved. When the content of the uminescent powder was more than 10wt%, the afterglow decay-time constants of luminescent Lyocell fibers were increased significantly, and the afterglow property of fibers was improved.
  • 研究 开发
    ; Meijie Yu
    . 2013, 44(17): 0-0.
    Structural features of fibers during the preparation of PAN carbonized fiber were investigated by X-ray diffraction including both two-dimensional and plane scanning examinations. The differences of crystalline structures and crystalline orientation of dry-jet-wet spinning precursor fibers during pre-oxidation and carbonization were revealed. The results show that the evolutional laws of orientation and crystallinity of fibers in the different stages are observed intuitively by the two-dimensional diffraction patterns in the equatorial direction. Compared with the precursor fiber, the orientation, crystalline size and crystallinity are increased and the interplanar spacing has no obvious change for 205℃pre-oxidized fibers. While, for 235℃pre-oxidized fibers, the orientation, crystalline size and crystallinity are decreased and the interplanar spacing is increased. Compared with the precursor fiber and pre-oxidized fibers, the orientation, crystalline size, crystallinity and interplanar spacing of fibers are decreased obviously during the carbonization.
  • 研究 开发
    ;;Qing-Quan BIAN
    . 2013, 44(13): 0-0.
    Modified polyolefin microporous membrane was prepared as the separator for Li-ion batteries by surface radiation coating of methoxy poly (ethylene oxide) acrylate ester. The modified membrane can be well wetted by liquid electrolyte. The ion conductivity of the membrane is easily achieved by absorbing the liquid electrolyte due to the high amphoteric character surface. With the modified membrane as a separator, the graphite/cathode cell exhibited a good capacity retention.It is also found that the Li-ion cell fabricated in this manner not only has stable capacity retention, but also show good high-rate performance.
  • 研究 开发
    Juan LIZheng-Peng LIU;;;
    . 2014, 45(07): 0-0.
    The mechanism of hydrogen plasma passivation for poly-Si thin films has been investigated. It has been found that different kind of hydrogen plasma radical is responsible for different defects passivation for poly-Si. The Hα with low energy is mainly responsible for passivating the dangling-bond defects. The H* with higher energy may passivate the defects related to Ni impurity around the grain boundaries more effectively. In addition, the Hβ and Hγ with the highest energy are required to passivate intra-grain defects. These analysis and results are very usable to optimize the H plasma passivation and make the passivation more effective.
  • 研究·开发
    WANG Yuan;TANG Jian-guo;LIU Hai-yan;WANG Yao;LIU Ji-xian;HUANG Lin-jun;HUANG Zhen;XU Qiang-song;XIONG Lei;LIANG Yong
    . 2013, 44(11): 1584-1587.
    Polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) was synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization. The amphiphlic block copolymer, Polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) was evidenced by the means of 1H-NMR. This amphiphilic block copolymer was then dissolved in the toluene,which is a selective solvent for PS and P4VP respectively. And then studied the self-assembly behavior. Some testes show that the polymer in certain conditions can self-assemble into vesicle-like structures, which as an in-situ reactor successful preparation of nanosized silver composite materials. The result was characterized by UV-Vis spectra、X-ray diffraction (XRD)、scanning electron microscopy (SEM) and energy dispersive spectrometer(EDS).
  • 研究 开发
    ;
    . 2014, 45(04): 0-0.
    More Printed Circuit Boards(PCB) would be produced with the development of electronic industry. And more microdrills for PCB woluld be needed. This paper describes the development of microdrill material. And The Development of the Manufacturing Technique was discussed in details. Our country should do more work on the study of the rheology of powder extrusion,new formagen, forming process, coating technology and equipment matching technology.
  • 研究 开发
    ;;;Chuan-jie ZHANG;;Ping ZHU
    . 2014, 45(04): 0-0.
    Calcium alginate/gelatin (semi) interpenetrating polymer networks (IPNs) were prepared with oxidized sodium alginate as a crosslinking agent. The structure and thermal stabilities of (semi) IPNs were characterized by Fourier transform infrared spectrometer (FTIR) and thermogravimetric analysis (TGA), respectively. And in contrast with calculated TGA data, the reactive mechanism in the blending process was studied. Compared with the thermal stabilities of (semi) IPNs crosslinked with glutaraldehyde, the results indicated that the thermal stabilities of (semi) IPNs crosslinked with oxidized sodium alginate were similar to those crosslinked with glutaraldehyde. And oxidized sodium alginate could be instead of toxic glutaraldehyde to crosslink the calcium alginate/gelatin (semi) IPNs system, and physical and/or chemical reaction may take place in the blending process.
  • 工艺 ·技术
    ZHENG Bin-bin;HUANG Zhen-fu;ZHUN Shun;YAO Yu-yuan;LV Wang-yang;CHEN Wen-xing
    . 2013, 44(02): 294-298.
    Cobalt tetrasulfophthalocyanine (CoPcS) was synthesized, characterized by Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectra (TOF-MS), Fourier Transform Infrared Spectra(FT-IR)and Ultraviolet and Visible Spectra (UV-Vis). CoPcS modified by cyanuric chloride was supported onto silk fibers(SF) to obtain a novel supported catalyst (CoPcS-SF). The catalytic oxidation activity for Acid Orange Ⅱ (AO2) was investigated in the presence of H2O2. The experimental results showed that AO2 could be efficiently decomposed in CoPcS-SF and H2O2, and more than 97% of AO2 in 60 min was eliminated at initial pH 7. Moreover, CoPcS-SF could be recycled. The effects of pH, the electrolyte of NaCl and temperature indicated the reaction could efficiently proceed in a wide pH range from 3 to 9, and the reaction rate could be obviously enhanced when NaCl was present, increasing with the elevation of the temperature. FT-IR and Gas Chromatography/Mass Spectrometry (GC-MS) analysis showed that AO2 was mainly oxidized into some small molecular biodegradable aliphatic carboxylic compounds such as maleic acid, fumaric acid, succinic acid, etc.
  • 研究 开发
    Bin LIU
    . 2014, 45(04): 0-0.
    Low-cycle fatigue behavior of cast AlSi9Cu3 aluminum alloy under different strain amplitudes were studied. Fatigue behavior were tested by MTS, the relationship between strain amplitude and fatigue life were revealed . Fatigue fracture were analyzed by optical and scanning electron microscope. The research results show that :under low-cycle fatigue loading condition ,the cast AlSi9Cu3 aluminum alloy can exhibit the continuous cyclic strain hardening or initial cyclic strain hardening followed by cyclic stability, and the bigger of strain amplitude, the higher of hardening rate; A single-slope linear relation between plastic strain amplitude, elastic strain amplitude and reversals to failure is observed from cast alloy ,the experimental results conform to the Coffin - Manson formula. Fatigue fracture of material observed by SEM, the width of the fatigue stripes is related to strain amplitude, fatigue damage is related to the strain amplitude also.
  • 工艺 技术
    Ji-Xiang ZHU;;Yang Fan-Wen
    . 2013, 44(17): 0-0.
    Chitosan scaffolds were fabricated via freeze-drying chitosan gel using genipin as a crosslinking agent. The influence of the preparation technology to the property of scaffold was studied and the results showed that scaffold fabricated from a neutral pre-gelled chitosan solution displayed highly interconnected and uniformly distributed pores and a porosity over 90%. This scaffold also showed higher water absorption and BSA adsorption. Compressive tests demonstrated that this scaffold had significant elasticity and maintained its physical integrity even after compressing them down to 20% of their original height and the elastic modulus reached 81kPa. Adhesion and proliferation of PC12 cells on this scaffold showed excellent properties by MTT and SEM observation, which indicated the potential for nerve tissue engineering applications.
  • 研究 开发
    Kui Li;Qi Zhu;Huiying Chen;;ma-tai DING;
    . 2014, 45(04): 0-0.
    The effect of polyethylene glycol (PEG) molecular weight and concentration on the performance of PES hollow-fiber membranes, fabricated by phase inversion process, was investigated. The results demonstrated that the rejection and tensile strength decrease gradually when the PEG molecular weight increases from 600 to 20000. Meanwhile, the pure water flux first increases and then decreases, which reaches the maximum value of 177.41 L/h?m2 at the PEG molecular weight of 6000. In addition, with the increase of the PEG-6000 concentration from 4% to 10%, the pure water flux gradually increases, whereas both the rejection and tensile strength gradually decrease.
  • 研究 开发
    Xiao-Ling Gai
    . 2013, 44(13): 0-0.
    In order to study the effect of sound-induced vibration on the sound absorption properties of three-leaf microperforated panel absorbers, sound absorption properties of three-leaf microperforated panel absorbers are computed based on the microperforated panel theory and electro-acoustical equivalent circuit principle. Results show that the low-frequency sound absorption properties of three-leaf microperforated panel absorbers decrease and high-frequency sound absorption properties of three-leaf microperforated panel absorbers change little considering sound-induced vibration. And the sound absorption performance curves of three-leaf microperforated panel absorbers considering sound-induced vibration are gradually closed to the condition without considering sound-induced vibration with the increasing of the mass density. Two resonance peaks moves toward low frequency region with the increasing of the pore diameter and distance of microperforated panel and moves toward high frequency region with the increasing of the perforation when other parameters keep invariant. In conclusion, the sound absorption performance of three-leaf microperforated panel absorbers is affected by sound-induced vibration and the variation degree of sound absorption performance depends on the mass density and structure parameters of microperforated panel.
  • 研究 开发
    . 2013, 44(13): 0-0.
    Abstract: The yellow Organic light-emitting devices(OLED) were fabricated by evaporation method using R-4Band GIr1(red and green phosphorescent materials). Thedevice structure used here was ITO/MoO3(X)/NPB(40nm)/ TCTA(10n m)/CBP: GIr114%:R-4B2%(30nm)/BCP(10nm)/Alq3(40nm)/LiF(1nm)/Al(100nm),TCTA and BC P were electron and hole block layer separately. We investigated the efficiency and chromatic-stability characteristics of these fabricated devices through the method of optimization of the thickness of the MoO3.The optimum performance of OLED was achieved by the application of 90nm MoO3.The maximum EL efficiency and luminance reached 29.2 cd.A-1 at 7.13mA.cm-2、2081cd.m-2and 24430cd.m-2 at 151.7cd.m2、16.0cd.A-1 respe-ctively.Moreover,Commission International De L’Eclairage(CIE)coordination of(0.5020,0.4812)、(0.4862,0.4962)、(0.4786,0.5027)were obtained at 5、10、15V. The enhanced efficiency and good chromatic stability were attributed to the balanced carrier injection and transport as well as the effective confinement to the light-emitting region with barrier layer.
  • 综述 进展
    Yan-Hong WANG ;;;;
    . 2013, 44(22): 0-0.
    As is well known, the electric vehicle is a very important alternative transportation and gains more and more attentions due to the shortage of conventional fossil energy. Recently, some self-ignition accidents of the electric vehicles happened in last two years make the people recognize the importance of the safety of the battery. Therefore, the safety of the battery is the key for practical application of the electric vehicles, and therein the thermal management of battery is very important. In last decade, the thermal management system employing a novel phase change materials (PCM) has been designed and researched for lithium-ion battery. Compared to conventional thermal management systems, e.g. air/liquid-cooling, the PCM-based system has more advantages: compact, high efficient, energy conservation, little temperature variation, preventing thermal runaway etc. But the shortcomings of low heat conduction coefficient and difficultly compositing with other materials restrict the application of the PCM. Extensive efforts have been undertaken to improve the PCM performance. In this review, we introduce the recent development of the PCM-based thermal management system, and especially present the new researches in improving the thermal conductivity of the PCM by using the wax/graphite matrix. In the last, we give the conclusion and outlook, and think that the composite PCM microcapsule with high heat conduction and complex structure is the future trend.
  • 研究与开发
    ;;;;
    . 2012, 43(S2): 0-0.
    The current-voltage characteristics of the single-crystalline Tm2O3 high-k gate dielectric thin films, which were epitaxially grown on p-Si (001) substrates by molecular beam epitaxy, have been measured at different temperatures. Temperature-dependent leakage current measurements indicate that Schottky emission is the dominant transport mechanism in the Tm2O3 dielectric films at positive biases, while Frenkel-Poole conduction is the main reason for the leakage currents at negative biases.
  • 研究 开发
    XIANG Weidong ;;;
    . 2014, 45(04): 0-0.
    Recently, the newly environmental friendly I-III-VI semiconductor quantum dots (QDs) AgInS2 has received significant progress by virtue of its excellent properties of quantum dots and the advantage of low-toxic. Therefore, it is expected to replace Cd-based quantum dots in various applications. Focus on the advances at home and abroad, the status and the existing problems of AgInS2 quantum dots are summerized and discussed. Furthermore, the prospects of the related research are presented.
  • 研究 开发
    Da-Ming BAN;
    . 2013, 44(13): 0-0.
    The flame retardant, poly(hydroquinone phenyl phosphate) was prepared by bulk polymerization with phosphorus oxychloride, hydroquinone and phenol in two step procedure. The structure of polymer was confirmed with FTIR, 1H, 13C and 31P-NMR spectrum. Thermal stability of polymer was investigated with thermogravimetric analysis. The result shows that structure of polymer is agree to expect. The polymer shows good thermal stability by giving initial decomposition temperature of 364℃; the fastest decomposition temperature of 547℃; and 36% residua at 700℃.
  • 研究与开发
    Gang Dong;Zhong-Qi Zhu;Qing-Ju Liu
    . 2012, 43(03): 294-298.
    Abstract: The TiO2 photocatalyst samples doped with nickel were prepared by sol-gel method. The samples were analyzed by XRD,XPS, FT–IR, UV–Vis, PL et al. The photocatalytic activity of the samples doped with different nickel 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 Ni-TiO2 samples are a mixed phase of anatase and rutile and the threshold wavelength is red shift about 55nm. The nickel doping inhibits the growth of crystallite size and transformations of crystallite phase from anatase to rutile and the photocatalytic activity is improved. The activity of the sample prepared at 500℃, n (Ni): m(TiO2)=1: 100 is the best under fluorescent lamp and is obviously highter than that of Degussa P25.
  • 研究 开发
    Xiang-Lei WANG ;;;
    . 2013, 44(23): 0-0.
    Form-stable phase change composites were prepared by melt blending and hot-compaction of paraffin, expanded graphite (EG) or flake graphite (FG) and high density polyethylene (HDPE). In the composites, paraffin serves as a latent heat storage material, EG or FG as a heat transfer promoting agent and HDPE as a matrix. Phase transition temperatures, latent heat values and thermal conductivity values of the composites have been measured. In order to prevent the leakage of melting paraffin in the composites, the minimum weight percent for HDPE is 35%. The latent heat of the composites increases with increasing mass ratio of the paraffin in the composites. EG and FG can improve thermal conductivity of the composites significantly. When the addition of EG was in the ratio of 10wt%, thermal conductivity of the PCM was up to 2.50 W/m K, more than 6 times of that without any additives, which was much better than that by addition of FG.
  • 研究与开发
    Xiao-Bing Luo;Li Zhang;Ming-Bing Zhou
    . 2012, 43(03): 371-374.
    The functionally gradient material of poly (vinyl alcohol)/ nano-hydroxyapatite/polyamide66 for repair of articular cartilage and underlying bone was prepared by freeze-thawing method and thermally induced phase inversion processing technique. The mechanical and friction property of PVA were tested. The biocompatibility and mechanical property of nHA/PA66 scaffold were also investigated. The results showed that the tensile strength of PVA was 1.94MPa, the mean of friction coefficient in physiological saline and in plasma substitute were 0.076 and 0.085, respectively. The n-HA/PA66 scaffolds exhibited high porosity (about 80.93%) and a pore size ranging from 50 to 500 um. The compressive strength and modulus of scaffolds were 0.88 MPa and 15.21 MPa. Such a material exhibited good biocompatibility and high bioactivity.
  • 研究 开发
    ; ;Ying Zhang
    . 2014, 45(04): 0-0.
    Polycrystal ceramics of Pb(Zr0.52Ti0.48)O3 with tetragonal phase and average sizes of uniformly distributed grains being 2~3μm were prepared through a conventional solid state route. In-situ Raman measurements on individual single grain and multiple single grains in subsequence were carried out under a stress field by employing a four-point bending load. The relative intensity ratios of optical modes at lower Raman shifts (IE(1LO)/IE(2TO) and IE+B1/IE(2TO)) under different applied stresses were calculated by normalizing peak intensity. The results revealed that the values of (IE(1LO)/IE(2TO) and IE+B1/IE(2TO)) decreased with the increases in the applied tensile or compressive stresses, while increased with the extension of applying time. The values of (IE(1LO)/IE(2TO) and IE+B1/IE(2TO)) varied with the alterations of applied stresses on different single grains. However, the peak position of Raman spectra remained unchanged.
  • Research & Development
    MA Ruolan, XIONG Dingbang, FAN Genlian, TAN Zhanqiu, LI Zhiqiang
    Jorunal of Functional Materials. 2022, 53(8): 8085-8091. https://doi.org/10.3969/j.issn.1001-9731.2022.08.012
    Porous copper powder is ideally used for catalytic growth and chemical loading owing to unique pore structure and large specific surface area. However, limted to small size and high surface activity of the powder, few studies on the preparation of porous copper powder were reported. In this paper, porous copper powder was successfully prepared by vapor phase dealloying using ball-milled Cu-Zn alloy powder as precursor. The effects of dealloying temperature, dealloying time, initial alloy composition and ball-milling deformation on the properties of dealloyed powder were investigated by SEM, EDS, XRD and TEM. Results indicate that evolution of pore structure is a product of the competition among the dealloying driving force of Zn atom, the surface diffusion velocity of Cu atom and the body diffusion velocity of Cu atom. The coarsening process of surface pores is dominated by the surface diffusion of Cu atoms, which causes the shrinkage of pore structure. The dislocation introduced by ball milling reduces the diffusion activation energy of pore coarsening process by providing a fast diffusion channel and speeds up the process of dealloying. The maximum average surface porosity of the prepared porous powder is 17%, and the average pore size is 0.6-1.1 μm, which both can be controlled by adjusting process parameters.
  • 综述 进展
    ;zhang dong
    . 2015, 46(03): 0-0.
    With the deterioration of electromagnetic environment, it is quite urgent to explore a range of effective electromagnetic shielding materials in the field of material development. In this paper, the mechanism and normal measurements were simply introduced, and according to classification of metal and conducting polymer materials, advances in preparation and application of electromagnetic shielding materials were reviewed, what’s more, further developments of electromagnetic shielding materials were also proposed.
  • 研究 开发
    . 2013, 44(19): 0-0.
    LiNi0.5Mn1.5O4 cathode materials were synthesized by solid state method using Ni(CH3COO)2?4H2O、Mn(CH3COO)2?4H2O as starting materials,then decomposed to get nickel manganese oxides at 400 ℃ and 500 ℃for 3h or 7h,Joined and mixed the source of lithium Li2CO3. The sample calcination in air at 800 ℃ for 12h and then annealed at 600 ℃ for 24h. XRD、SEM、EIS and charge-discharge performance tests showed that LiNi0.5Mn1.5O4 delivered the best electrochemical performance by used precursor made at 400 ℃ for 7h. Its initial specific discharge capacity Was 141.5mAh?g-1 when 0.1C charge-discharge at room temperature,and after 30 cycles the capacity retention is 98.59%;when charged-discharged at 1C initial capacity Was 120.34mAh?g-1,and after 30 cycles the capacity was 112.09 mAh?g-1.