15 March 2015, Volume 46 Issue 05

    

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研究 开发
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  Influence of microstructure on the corrosion behavior of lead alloys

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  . 2015, 46(05): 2-0.

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  Lead alloys have been widely applied in hydrometallurgical electrowinning industry due to their high stability in H2SO4 system. Their corrosion resistance not only affects the cost, but also determines the quality of cathode product. Hence, corrosion resistance is a critical factor to evaluate the performance of lead alloys. The effects of grain size, morphology and distribution of second phases, and rolling process on their corrosion behavior are briefly reviewed. The microstructure feature of lead alloys with ideal corrosion resistance is summarized, and the prospects of grain boundary engineering and micro-analysis of localized corrosion behavior of lead alloys are also proposed.
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  Synthesis of Nano-SiO2 and Research of Their Influence on the Properties of Dental Resin

  . 2015, 46(05): 3-0.

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  Silica microspheres are important fillers in dental resin. The aim of this study was to investigate its effect on dental resin. In this paper, silica microspheres were prepared by sol-gel method and then were applied in dental composite after modified. The appearance and properties of SiO2 microspheres and dental composite were characterized with SEM, TEM, laser diameter analyst, tensile test and DTA. The results revealed that SiO2 microspheres showed a global, regular contour with homogenous size and distribution with 450nm as the average diameter. With increasing of silica content, the flexural strength and Compression strength first increased and then decreased. The roughness and cracks increased, the storage modulus E’ tended to increase, the glass transition temperature Tg increased. Finally, the content of silica reaches 45wt%, it has good compatibility with dental resin, the flexural strength and Compression are 123.682MPa and 208.802MPa respectively, E’ and Tg reach maximum.
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  Preparation and control release properties of chitosan electrostatic assembly with polyanion bearing phosphorylcholine groups

  Ming GONG

  . 2015, 46(05): 4-0.

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  Novel polyelectrolyte hydrogels were prepared by polycation chitosan (CS) and polyanionic poly(2-methacryloyloxyethyl phosphorylcholine-co-methacrylic acid) (poly(MPC-co-MA), PMA30). The PMA30 (the actual percentages of MPC unit in PMA30 determined by 1H-NMR was 28%) was synthesized by free radical polymerization of 2-methacryloyloxyethyl phosphorylcholine (MPC) and methacrylic acid (MA). Fourier transform infrared spectra (FTIR) and scanning electron microscopy (SEM) con?rmed that the formation of the polyelectrolyte hydrogels was attributed to the strong electrostatic interaction between cationic groups in CS and anionic groups in PMA30. Potential applications of the hydrogels matrices in controlled drug delivery were also examined. In vitro release showed that neutral red release could be controlled by choosing the composition and pH. This facile method of fabricating CS/PMA30 hydrogels bearing phosphorylcholine groups may have potential applications in the ?elds of drug delivery, tissue engineering, and cell culture.
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  Synthesis and Optical Properties of Perovskite-type Oxide Sm0.5Sr0.5CoO3-δ

  Dong-Shan GAO;; ;

  . 2015, 46(05): 5-0.

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  Perovskite-type complex oxide Sm0.5Sr0.5CoO3-δ(SSC5) powders was prepared by sol-gel method with citric acid as chelate, and subsequently characterized by TG-DSC, XRD, SEM, XPS and UVPC. The results show that the SSC5 powders were formed at 1200 °C for 6 h, the grain size was approximately 1 μm. The states of cobalt have been changed into Co3+ and Co4+ as a result of the Sr2+ substitution for Sm3+, and a lot of adsorption oxygen species appear on the surface of SSC5. The solar absorptance (αS) and thermal emittance (εT) of SSC5 are 0.71 and 0.19, showing good spectral selectivity.
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  Preliminary study on grafting mechanism of laccase-catalyzed oxidation of protocatechuic acid onto the chitosan

  . 2015, 46(05): 6-0.

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  In heterogeneous condition for graft modification of chitosan with protocatechuic acid by laccase catalyzed oxidation, the relative concentration change in liquid was explored, as well as the reaction mechanism of grafting and enhancement of antioxidant properties of modified chitosan. ReactIR analysis showed the change of concentration of components in liquid phase, finding that protocatechuic acid was adsorbed onto chitosan before further reaction. Py-GC/MS analysis indicated that protocatechuic acid was connected to chitosan by chemical bonds. Further signs of chemical bonds onto chitosan were showed by Solid-state 13C NMR and FTIR analysis. Compared with the untreated chitosan，the grafted chitosan exhibited greatly improved antioxidant property, which were detected by ABTS radicals scavenging method.
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  Study on Modification of Sulphoaluminate Cement based Materials

  Hong-Bo TAN;

  . 2015, 46(05): 7-0.

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  The composite cement of flyash and sulphatealuminium cement was studied by compressive strength XRD TG and SEM on the basis of induced crystallization effect particle effect and priming effect, etc. The results show that, after adding M, the compressive strength of 2h 3d 7d and 28d have improved 140% 116% 80% and 60% respectively ; more Aft and alumina gel are produced in early age and samples become more compactness ; early phase crystalline forms of AFt may get poor; with the prolong of hydration time, crystalline forms of Aft improves , flyash participates in the send hydration reaction and is tightly binded by its hydration products, the system gets more compactness, so the long-term strength increases.
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  Performance of Ni(OH)2/reduced graphene oxides composites for supercapacitors

  ;shengzhong Kou ;;

  . 2015, 46(05): 8-0.

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  Composites of Ni(OH)2/reduced graphene oxides (rGO) were prepared by chemical co-precipitation method, in which Ni(OH)2 hexagonal nanoplates were successfully inserted between the layers of reduced graphene oxides. Thus the aggregation of rGO and Ni(OH)2 is efficiently prevented, and the stability of the composite also is improved. The electrochemical performances of Ni(OH)2/rGO were investigated as electrode materials of supercapacitor. When the mass ratio of Ni(OH)2 to rGO was 5.5:1, the composite achieved the best electrochemical performance, in which the specific capacitance of 1036F/g was achieved at a current density of 1A/g within a potential window of -0.1V~0.37V and maintained over 70% even after 3000 charge-discharge cycles at a current density of 4A/g.
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  Influence of etching on the structures and electrochemical properties of Sn0.4Co0.4Zn0.2 alloy

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  . 2015, 46(05): 9-0.

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  The Sn0.4Co0.4Zn0.2 alloy was synthesized using solid-state sintering and then treated by etching，and the influence of H2SO4 concentration on the structures and electrochemical properties were analyzed. Analysis results showed that Sn0.4Co0.4Zn0.2 alloy consists of CoSn, Co3Sn2, CoSn2 phase and zinc simple substance. Part of zinc was corrosion dissolved by H2SO4, which leads to the formation of many pores in the particle interior and the decreasing of size of particle of Sn0.4Co0.4Zn0.2 alloy. Etching improved the electrochemical properties of Sn0.4Co0.4Zn0.2 alloy. When the H2SO4 concentration was 0.02mol/L，the initial discharge capacity of Sn0.4Co0.4Zn0.2 alloy was 295mAh/g, the retention after 100 cycles retains 79.3%, which showed the Sn0.4Co0.4Zn0.2 alloy has good electrochemical properties.
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  Preparation of porous hydroxyapatite microspheres by multiple emulsion method assisted by ultrasonic

  Xiangnan LI;

  . 2015, 46(05): 10-0.

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  Porous hydroxyapatite(HAP) microspheres were prepared by a multiple emulsion method assisted by ultrasonic. With uniform size and irregular nano-pores of porous HAP microspheres were prepared by adjusting the factors of reaction temperature, time and pH value. The obtained microspheres were characterized using XRD, IR, SEM and TEM, and the experiment conditions on the product composition and morphology were studied. Results showed that the optimal temperature was 50℃, reaction time was 24 hours, and the pH value of the inner water phase was over 10. The prepared HAP microspheres deposited with nano HAP particles are porous and have an average diameter of 50~200nm. These porous HAP microspheres with an internal cavity are promising candidates for filler of skeletal defects and drug delivery.
工艺 技术
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  Preparation and application of nitrogen-doped graphene

  ;Qiu-Feng Lü

  . 2015, 46(05): 11-0.

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  Nitrogen-doped graphene has been widely used in the fields of electronic devices, photovoltaic industry, sensors and so on, due to its unique properties. In this work, we systemically analyzed and discussed on the current main preparation methods, structures and properties of different dimensions of nitrogen-doped graphene, and thereby the applications of nitrogen-doped graphene. Finally, based on the current status of researches, challenges and future trends of nitrogen-doped graphene were concluded.
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  Effect of the doping ions type on the photocatalytic activity of TiO2 nanotubes

  ;Bei-hai ZHOU ;

  . 2015, 46(05): 12-0.

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  Ag+, Cu2+, Fe3+, Mn2+ and V5+ doped TiO2 nanotubes with ions amount of 1.0% (atomic percent) were synthesized via a hydrothermal method. With the increase of the calcination temperature, the specific surface area decreased. The intensity of anatase phase declined with enhancing the calcination temperature, and then decreased. The energy band gap of TiO2 nanotubes became narrower with the calcination temperature increased. The specific surface area decreased, the weight fractions of anatase phase increased and the energy band gap became narrower when metal ions were doped into the catalyst. The photocatalytic activity of the catalyst was improved when Ag+, Cu2+, Fe3+ and V5+ ions were doped into TiO2 nanotubes, but was declined slightly when Mn2+ ions were doped. The 1.0% Fe3+-doped TiO2 nanotubes calcined at 550°C had the highest photocatalytic activity, with an HA removal rate of 77.4%.
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  Preparation and application of hydantoin epoxy resin

  Gong-Wen TANGXin Huang

  . 2015, 46(05): 13-0.

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  Hydantoin epoxy resin is a new type of special epoxy resin, which was glycidylated hydantoin and its derivatives. It maintains the performance of ordinary epoxy resin. More over, heterocyclic structure of hydantoin makes hydantoin epoxy resin with good electrical isolation, heat resistance, weather resistance and abrasion performance. In this review, the preparation of 1,3-glycidyl hydantoin, glycidyloxy hydantoin epoxy resin and hydantoin epoxy resin with high molecular weight were reviewed. The current research status about the performances of hydantoin epoxy resin was reviewed. The application of hydantoin epoxy resin in the fields of electronic packaging materials, substrate material of copper clad laminate, insulation material, antibacterial agent and so on were described. The development trend of hydantoin epoxy resin was further predicted.
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  Accuracy in quantitative phase analysis of Portland cement clinkers by Rietveld method

  Pi-Qi ZHAO;

  . 2015, 46(05): 14-0.

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  The four main monominerals of Portland cement clinker were prepared through solid-state reactions and then mixed artificially to form clinkers. Accuracy in Rietveld quantitative phase analysis of these clinkers was studied by fitting analysis of X-ray diffraction pattern using Topas software. The results show that all of the correction factors, fc, are about 1±0.07, which indicates that the monominerals do not exist gross amorphous errors. Quantitative results obtained from Rietveld refinements of different artificial clinkers show the sums of absolute errors (SAE) are all about 5%. But the relative errors vary significantly from different phases. They are about 5% in the high-content phases (wt>25%) and between 8.3% and 16.8% in the low-content phases (wt<20%). Compared with quantitative results obtained from Rietveld refinements of step scanning (5s/step) and continuous scanning (2°/min) patterns, the refinements of former type have high precision value for the relative error analysis (SRE), especially for the SRE of C3S and C2S (about 4% lower than that of continuous scanning (2°/min) patterns). But the sums of absolute error (SAE) in the same sample are almost identical, about 1% of difference value of SAE.
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  Study on the Preparation of FeAl/Al2O3 as Tritium Permeation Barrier on 316L stainless steel

  . 2015, 46(05): 15-0.

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  The FeAl/Al2 O3 coatings for the tritium permeation barrier of the 316L stainless steel were prepared by magnetron sputtering、heat treatment and oxygen implantation .The phases、surface morphologies and chemical composition of the coatings were characterized by X-ray diffraction、 scanning electron microscopy and energy dispersive spectrdmeter individually .The results show that the high quality Al thin films were successfully deposited with magnetron sputtering process on 316L stainless steel, 170 ℃ and 1400 W were the optimized technological parameters. The transition layer was produced after heat treating, it is mainly composed of FeAl and with high bonding strength, the maximum bonding strength was 62.5N after heat treatment under 700℃,120min.After oxygen implantation, it obtained α and γ phase alumina coatings with 360nm thickness and high thermal shock resistance, the tritium permeation resistance was improved 3 orders of magnitude high than the 316L stainless steel bulk.
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  Preparation and characterization of histidine-grafted-chitosan/ poly(L-lactide) scaffolds

  . 2015, 46(05): 16-0.

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  Histidine-grafted-chitosan/ poly(L-lactide) (NHCS/PLLA) scaffolds were prepared through the dual phase separation technique by changing the mass ratio of NHCS/PLLA and the type of NHCS. Chemical structure, morphology and mechanical properties of NHCS/PLLA composite scaffolds were characterized through FT-IR, WXRD, thermal gravimetric analyzer and field-emission scanning electron microscope (FESEM). The pore size of NHCS/PLLA composite scaffolds decreased with the decrease of the mass ratio of NHCS/PLLA, making the density of NHCS/PLLA scaffolds larger. The pore size of NHCS/PLLA scaffolds were about 12~25 μm, the porosity were greater than 92%. The comprehensive strength and the comprehensive modulus were 0.33~0.78 MPa and 1.75~5.28 MPa respectively, which could be applied in cartilage tissue engineering.
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  Synthesis and characterization of ZnO one-dimensional nanomaterials

  . 2015, 46(05): 17-0.

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  Firstly，ZnO nanoparticles have been synthesized by using ethanol as solvent, zinc acetate as zinc sources and sodium oleate as surface capping agents through wet-chemical route. Then the needle-like ZnO nanowires bundles were synthesized by high temperature calcination method using the as-synthesized ZnO nanoparticals as raw materials. All of the as-synthesized samples were characterized by UV-Vis absorption spectroscopy (UV-Vis), fluorescence spectroscopy (FL) , transmission electron microscope (TEM) and scanning electron microscope(SEM). The results show that the obtained ZnO nanoparticals could give characteristic absorption peaks locating at 355 nm in the UV-Vis absorption spectra. FL spectra showed two mainly emission peaks centering at 400nm and 550nm. The sizes of ZnO nanoparticals is near 5nm with a narrow size distribution. The needle-like of ZnO nanowires bundles were synthesized when the calcination temperature was 500℃. The obtained hexagonal wurtzite structure ZnO single crystal nanowires with length about 10μm, diameter about 100nm. Meanwhile, the good ultraviolet luminescence performance of as-synthesized ZnO nanowires were also detected in this work.
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  Reaction Process of WC-Co Composite Powder by Direct Carbonized and in-Situ Synthesize

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  . 2015, 46(05): 18-0.

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  Using ammonium metatungstate (AMT), soluble cobalt salt, and organic carbon source as the raw materials, the WC-Co composite powder was fabricated by spray conversion method and direct carbonized in-situ synthesize method. The phase compositions, powder morphology of WC-Co composite powder were characterized by XRD, SEM. Results show that W was carbonized completely at 900℃ because of the promoting effect of Co phase, the carbonize temperature in this experiment of W was lower than the normal carbonize temperature far; The carbonization process of W depends on the reaction of the surface of tungsten powder particles and carbon which resolved from carbon atmosphere, and the diffusion of carbon to the inside of W particles, was a solid-solid reaction, W was carbonized into W2C firstly, and then carbonized into WC further because of the Gibbs free energy of W2C is lower than WC; The W/Co/C system reacted along the specific steps of WCo3，Co6W6C，W2C-Co and WC-Co; With the increasing of carbonize temperature, the reaction system can skip the first two steps, and generated W2C-Co directly, then carbonized into WC-Co composite powder further.
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  Characterization of hydroxyl Fe/Zr bentonite composite and its adsorption performance for selenium in aqueous solution

  ;Zheng-xian CHEN ;;;;

  . 2015, 46(05): 19-0.

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  Hydroxyl Fe/Zr modified bentonite (Fe/Zr-Bent) was prepared by the hydrothermal method and the samples before and after modification were characterized by SEM, TEM and XRD. Isoelectric point (pHzpc) was measured by the adding salt law. Adsorption performance, adsorption kinetics and possible adsorption mechanism were investigated. The characterization data showed that compared with bentonite before modification, morphology of Fe/Zr-Bent became rougher observed from SEM images, TEM images and XRD spectrum confirmed that nanoscale needle-like crystals of hydroxyl Fe/Zr irregularly distributed on the surface of bentonite. pHzpc of Fe/Zr-Bent decreased from 10.5 to 5.5, which carried positive charge beneficial to adsorb oxyanions selenium via ion exchange, complication and electrostatic interaction. The removal efficiency of selenium in aqueous solution was raised from 11.84% to 86.66%, which significantly enhance its adsorption performance. Adsorption process of selenium was fitting pseudo second-order model (R2＞0.997) and adsorption capacity was 46.73 mg/g.
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  Effect Factors and Mechanism of Solidification /Stabilization of Heavy Metals by Geopolymers

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  . 2015, 46(05): 20-0.

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  Geopolymer is a kind of inorganic polymer cementitious materials, which has a 3D network of silico-aluminate structures. Geopolymeric materials could be synthesized from calcined clays, industrial waste or other alumino-silicate containing source materials under alkaline conditions. Geopolymer has been hot point in immobilizing heavy metals in the recent years due to its unique structure and properties. Important factors that influence the solidification / stabilization of geopolymers are emphasized introduced, as well as current status of the researches on mechanism of immobilizing heavy metals are reviewed.
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  Study on the performance of Nano-copper film deposited by magnetron sputtering

  Jun-Ting GUO

  . 2015, 46(05): 21-0.

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  Abstract ：Nano-copper film was deposited on polyester needle-punched filter felt by Winding type magnetron sputtering equipment. The components and crystalline state of Nano-copper film were analyzed by using X-ray diffractometer (XRD). Atomic Force Microscope (AFM) is also used to characterize the microstructures of Cu thin films deposited on the surface of PET needled felt. The influence of the sputtering power, working pressure and deposition time on conductivity of copper coated PET needled felt was investigated systematically. Experimental results show that the conductivity and uniformity of copper film become better while the sputtering power is increased. However, it should be controlled under 6kw. With the increase of working pressure, the square resistance of Cu thin film increases with the decrease in the first, and thin film thickness become more uniform. As the extension of deposition time, the diameters of the copper particles increase, while the conductivity and uniformity of copper film significantly better.
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  Investigation on the construction conditions of carbon coating of core-shell LiFePO4/C composites via rate-discharge and cyclic performance tests

  Zhenxin Liu;;Yu XING ;;;;;

  . 2015, 46(05): 22-0.

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  There are many literature about the construction issues of LiFePO4’s carbon coating, of which is difficult to figure out the relevant details. However, the rate-discharge and cyclic performances are important for lithium-ion battery materials. Thus we conducted tests on the rate-discharge and cyclic performances to tell the differences between the functions of element-type and compound-type carbon sources and, in the mean time, to study the effects of carbon content as well as carbonization condition. The effects of element-type carbon sources (i.e., graphite nanopowder and acetylene black) and compound-type carbon sources (i.e., hydroxyethyl cellulose, polyethyleneglycol 2000 and glucose) on the electrochemical performance of LiFePO4/C were investigated. The bench research produced following results. The overall performances of glucose and graphite nanopowder are better than other carbon sources. In the case of using a certain carbon source, both carbon content and calcinations temperature have much more significant effects on the materials’ high-rate performances than their low-rate performances. In the case of using a certain carbon content and a certain calcinations temperature, the factor of carbon source has effects to some extent on the initial low-rate performances of LiFePO4/C composites, has a little more significant effects on their low-rate cyclic performances, and has very significant effects on their high-rate performances.
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  Preparation of Hydrophobic Silica Aerogels by Ambitient Pressure Drying Method

  Yang LIU ;

  . 2015, 46(05): 23-0.

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  Hydrophobic silica alcogels were prepared with tetraethylorthosilicate (TEOS) as precursor, hydrochloric acid and ammonia as catalysts, and trimethylchlorosilane (TMCS) and hexane as a surface modifying agent by drying at ambient pressure. Test methods, such as X-ray diffraction, SEM, BET, FTIR were adopted to analyze the surface morphology, structure and chemical composition of the samples. The results show that the specific surface area of the resulting SiO2 aerogels is up 900 m2 /g. The areogels have a density less than 200 kg /m3, and the hydrophobicity of aerogels is excellent.
研究 开发
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  Surface adsorption and diffusion of Nb-Si-N nano-composite films: A first principles study

  Yuan Ren ;;

  . 2015, 46(05): 24-0.

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  The adsorption and pathways processes of atomistic Nb, Si and N at some high symmetry sites on NbN(001) surface were studied with the first principle method which is based on density functional theory (DFT). The investigation presents some results. The potential energy surface (PES) was obtained by calculating the adsorption of Nb, Si and N atom on NbN(001). Nb atom on NbN(001) surface of the lowest energy position was HL, but, lowest energy position of N and Si atom between the HL and TopN. By the results of potential energy surface calculations, the minimum energy paths (MEP) of the single-atom on NbN(001) surface diffusion: Nb and Si atom were diffused from TopN to HL position; N atom was diffused from TopNb and the TopN-HL to HL position respectively. The diffusion energy of Nb, Si and N atom on NbN(001) surface were 0.32eV, 0.69eV and 1.32eV, respectively.
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  Preparation and Photoelectrocatalytic Activity of Visible-Light-Sensitive TiO2/Graphene Composite

  Fei Ye;

  . 2015, 46(05): 25-0.

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  Graphene oxide was prepared by the modified Hummers method. Using the graphene oxide and Ti(SO4)2 as the initial reactants, TiO2/graphene oxide composite was prepared by nucleation growth of TiO2 nanoparticles in the graphene oxide interlayer after Ti(SO4)2 hydrolysis. Then, TiO2/graphene composite was prepared through reduction by hydrazine hydrate. The composite was characterized by XRD, FE-SEM, HR-TEM, TGA, UV-Vis, TBE and the electrochemical measurements. Under visible light irradiation(λ＞420nm), using the composite as working electrode, platinum electrode as counter electrode, and saturated calomel electrode as reference electrode, the photoelectrocatalytic activity of the composite for the decomposition of acid red B which contains azo chemical health was studied. The results showed that the composite has a good response to the visible light, and the catalytic activity of the composite was increased under the condition of increased electrode voltage.
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  The performance of spraying polyurethane elastomer as pipeline insulation materials

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  . 2015, 46(05): 26-0.

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  Prepared the spray polyurethane insulation waterproof coating using the process of diesels rotational. Compared the water absorption thermal conductivity, density, hydrostatic pressure resistant with traditional thermal insulation materials by experiment，and tested the corrosion resistance to sea water and the deep sea insulation performance. The experimental results show that the spraying polyurethane insulation materials can meet performance requirements pipeline insulation in the water depth above 500m.
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  Research on Properties of Metamaterial Absorbers in Multi-layer configuration

  Yuan-Yuan DongHui Huang;Chu shun Zhang;Tian-yuan Zhan

  . 2015, 46(05): 27-0.

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  Based on the typical scheme of electromagnetic metamaterials designed for absorbing, this paper presents an improved scheme: multi-layer configuration. We focus on the absorbing properties of 2 types of multi-layer configurations: with the same units and different units, respectively. The simulation results show that for the same units type, higher absorbing rate and extra multiple curve peaks can be got if we increase the number of the layers properly. Moreover, as to the different units type, it can be made not only with the above advantages: multi-working bands, high absorbing rate and wide frequency range, but also with a nearly 100% absorbing rate, as a perfect absorber.
工艺 技术
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  Preparation and electrorheological properties of core-shell-structured TiO2/Urea particles

  Shuang Huo;Xu-Feng DONGmin qi Suokui Tan;

  . 2015, 46(05): 28-0.

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  Core-shell-structured TiO2/Urea nanoparticles were synthesized with tetrabutyl titanate and urea by using a hydrolysis method. The microstructure of the particles were observed by scanning electron microscope (SEM) and transmission electron microscopy (TEM), which indicated that the particles are monodispersed sphere (400~500nm) with complete core-shell structure. FTIR results further proved that the surface of the TiO2 particles is coated with urea. X-ray diffrantion (XRD) results indicated that the particles present amorphous structure. Both TiO2/urea particles and TiO2 particles were used to prepare electrorheological (ER) fluids with the same particles volume fraction. Their ER properties were tested and compared. The results indicated that the TiO2/urea particles-based ER fluid presents much higher yield stress than the pure TiO2 particles-based material. Besides, the shear stress of the TiO2/urea particles-based ER fluid keeps stable within a wide range of shear rate.
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  Synthesis and optical properties of CuInS ternary quantum dots

  Hai-cheng WangXue ZHANG;Jie ZHOU;Yi YAO;Ruiwei Wu;Ling DENG;Zhiran YAN;Jin CAO

  . 2015, 46(05): 29-0.

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  Ternary CuInS quantum dots were synthesized by decomposition of precursor, and the effect of synthesis parameter on the morphology and optical properties of CuInS nanocrystals was investigated. It is found that the particle size and optical property of CuInS crystals could be affected by reaction time and temperature. With increasing reaction time, the CuInS nanocrystals grow larger, accompanied with appearance of rodlike crystals and red shift of the peak of the fluorescent emission spectra. With increasing reaction temperature, the nucleation rate and the growing rate of nanocrystals increase as well as the particle size, also the shape of nanocrystals can vary from single sphere to mixing of sphere and rod, and red shift of emission peak will happen as well. Analysis of X-ray photoelectron spectrometer shows that as-synthesized particles are nanocrystals. This work would build foundation for further manufacture of non-toxic quantum dots light-emitting devices (QLEDs).
综述 进展
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  Review on self-healing of Engineered Cementitious Composites materials

  Li li Kan;;

  . 2015, 46(05): 30-0.

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  This paper summarizes Engineered Cementitious Composites (ECC) Materials and the self-healing of crack based on many domestic and international references. Maximum allowable width of crack and mechanism are emphatically introduced. Using its unique crack width control and tight micro-crack property combined with low water-binder ratio and pozzolanic effect of mineral admixtures to realize effective self-healing potential are put forward. Finally, the research challenges and further research direction in this field are pointed out, which provides valuable theoretical reference for crack self-healing research.