bluuebunny/crossref_metadata_2025 huggingface dataset:
Properties and Benefits of Biomass Briquetting of Macrophytes in Nansi Lake
Authors: Gong Ling , Wang Zhen Yu , Zhang Ming Quan , Li Feng Min
Published: March 2013

In order to provide a new technique for macrophytes use, this study evaluated the effect of biomass content on properties of biomass briquetting. Take lime as the binder, the best addition of biomass was 45%. In such case the drop strength of giant reed and reed briquetting reached maximum 55% and 74% respectively, and water impermeability reached minimum 15% and 7% respectively. Calorific value of biomass briquetting was between 11.1 MJ/kg and 14.9 MJ/kg and ash content was between 38.6% and 45.5%. Take giant reed briquetting as the example, 25% of money could be saved if briquetting replaced coal and people in Nansi Lake would get $159,333,333 a year. Also biomass briquetting could bring some environmental benefit including purifying water, slowing the greenhouse problems and acid rain. This study could provide a support for wetland restoration of the ecosystem, water quality, and the improvement of the economic benefits.
The Study of Life Cycle Assessment of Propylene Carbonate Manufacturing
Authors: Meng Xian Ce , Li Chen , Wang Zhi Hong , Gong Xian Zheng , Fang Ming Hui , Zhao Ming Nan
Published: March 2013

This study attempted to estimate the environmental performance of poly (propylene carbonate, PPC) in the whole life cycle. The life cycle is from raw materials, energy acquisition, manufacture, transportation, to the final disposal, sequentially. The environment impacts of these phases are assessed by the method of Life Cycle Assessment (LCA) to identify key aspects of environmental loads involving global warming, non-renewable resource consumption, and acidification effects and so on. Moreover, a comparative study due to manufacturing of PPC in its whole life cycle was taken to reveal which stage would make the most environmental load.
Degradation of Sodium Dodecyl Benzene Sulfonate by Bentonite, TiO2, and TiO2-Bentonite
Authors: Wen Shu Yao , Ma Zhan Qing , Ma Min Li , Chen Su Yun , Li Li , Jiang Jun
Published: March 2013

The photodegradation of organic pollutants by TiO2 has previously been shown to be efficient, but the TiO2 particles are typically so fine that they are easily washed away. This problem was solved by forming a complex between TiO2 and bentonite. Four different photodegradation conditions (i.e., no catalyst, addition of 3 bentonite, addition of 1 TiO2, and addition of 3 TiO2-bentonite) were investigated for their degradation efficiencies of 20 mg/l sodium dodecyl benzene sulfonate (SDBS) under ultraviolet light for 6 h. The titanium content of 1 titanium oxide was equal to that of the 3 Ti-bentonite. The results showed that, under the four above conditions, 36.7%, 25.9%, 96.7%, and 99.3%, respectively, of SDBS were degraded in the aqueous solutions. The latter two conditions degraded SDBS more efficiently than the former two conditions. The TiO2-bentonite complex possessed more advantages than TiO2 or bentonite alone, making the bentonite an appropriate carrier for TiO2.
Synthesis of Bi0.5Sb1.5Te3/Graphene Composite Powders
Authors: Liang B.B. , Li Y. , Xu L.L. , Wang L.J. , Jiang W.
Published: March 2013

In this paper, Bi0.5Sb1.5Te3/graphene composite powders were prepared by hydrothermal synthesis method. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) were used to characterize the morphology and structure of the composite powders. As a nanocomposite phase, graphene provided plenty of charge carriers and active sites for nucleation of Bi0.5Sb1.5Te3 grains. Bi0.5Sb1.5Te3 particles aggregated and attached to the surfaces of graphene randomly. In addition, it was found that the sizes of Bi0.5Sb1.5Te3 particles varied with different content of graphene. The formation mechanism of Bi0.5Sb1.5Te3/graphene composite powders was discussed.
The Structural Characterization and Optical Properties of Zinc Oxide Films Synthesized by Electrochemistry Method
Authors: Zheng Jing Xia , Zhao Xing Guo , Liang Wei , Xue Jin Bo
Published: March 2013

Flaky ZnO thin films were electrodeposited from an aqueous solution of zinc nitrate (Zn (NO3)2) as electrolyte on ITO glass substrate by cathodic reduction method The effect of electrolyte concentration on the structure, morphology and optical properties of ZnO thin films were studied by X-ray diffraction, scanning electron microscopy and UV-Vis spectrometer. The results show that the ZnO films are of hexagonal wurtzite structure; When the concentration of Zn (NO3)2 solution is 0.24 M, the sparse flaky ZnO thin films were prepared and the thickness and length of ZnO flaky are about 50 nm and 1~3 μm, respectively; When the electrolyte concentration is 0.16 M, hexagonal and triangular structures are observed and some lathy and conical ZnO structure start to appear; When the concentration of Zn (NO3)2 solution drops to 0.08 M, the matrix of films is still flaky ZnO, but porous structures among the flaky structures appear and the size of conical ZnO has changed, whose bottom diameter reaches 1~3 μm and length is 2~4 μm; UV-Vis absorption test results indicate the absorption peak and the bandgap of the prepared ZnO thin films are about 350 nm and 3.28 eV, respectively.
Preparation of CdSe-TiO2 Nanotube Array Films and their Photoelectric Properties under Visible Light
Authors: Yang Fei , Liang Wei , Xue Jin Bo
Published: March 2013

In this paper, CdSe-TiO2 nanotube array composite films were successfully prepared through a two-steps method. TiO2 nanotube arrays were firstly prepared by anodic oxidation method, based on which the composite films of CdSe-TiO2 nanotubes arrays were prepared by electrochemical deposition. The influence of the concentration of SeO2 on the structure and photoelectric performance of the composite films were studied by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and photocurrent response tests. The results show that the cubic phase CdSe particles with the size of about 15~20 nm were uniformly distributed in highly ordered TiO2 nanotubes and around the mouths of the nanotubes; With the increasing of concentration of SeO2, the content of CdSe increases gradually while the photocurrent density of the composite films increased and decreased, The optimal photoelectric performance of composite films were obtained when the SeO2 concentration was 4 mmol/L.
Synthesis and Thermoelectric Properties of Nd-Doped Uddlesden-Popper Phase SrO(SrTiO3)n (N=1,2) Oxides
Authors: Li Liang Liang , Sun Rui Rui , Qin Xiao Ying , Liu Yong Fei , Guo Guang Lei
Published: March 2013

The Nd-doped SrO(SrTiO3)n (n=1,2) bulk samples were prepared by combining a sol-gel method and spark plasma sintering (SPS). The microstructures of the precursor powders were characterized by X-ray powder diffraction (XRD) and scanning electron microscope (SEM), thermogravimetric (TG) and differential scanning calorimetry (DSC). The oxides of (Sr1-xNdx)n+1TinO3n+1(n=1,2;x=0.05, 0.1) were prepared by solid-state reaction of the precursor powders with post-spark plasma sintering for the first time and the thermoelectric properties showed that electrical resistivity ρ and the absolute values |S| of Seebeck coefficient increased with temperature and depended on the dopant concentration, indicating a n-type degenerate semiconductor behavior. Compared with the total thermal conductivity κ (4.1-5.2 Wm-1K-1) at room temperature, the estimated electronic thermal conductivity κe(0.2-0.7 Wm-1K-1) were very small, indicating that lattice contribution was predominant in the RP phase compounds. The largest dimensionless figure of merit ZT, 0.13 at 905K, was obtained the 10 at.% Nd-doped Sr3Ti2O7. This synthetic method provides a simple way to prepare thermoelectric oxides.
Preparation of Small-Diameter Silk Fibroin Tubular Scaffolds with Electrospinning Method
Authors: Zhu Jing Xin , Ma Yan Long , Asakura Tetsuo
Published: March 2013

In recent years, electrospinning has received much attention to prepare porous tubular scaffold due to electrospun nanofibers mat, which can mimic the structure characteristics of the extracellular matrix (ECM). In the present paper, silk fibroin (SF) tubular scaffolds with small-diameter were prepared by electrospinning from regenerated silk fibroin (RSF) aqueous solutions with rotating mandrel collector. The morphology and fiber diameter distribution of SF tubular scaffolds were influenced much by the concentration of regenerated silk fibroin (RSF) solution, collecting distance and mandrel diameter. The results showed that SF tubular scaffold, which was in flat surface with smaller fiber diameter and uniform distributed, could be obtained at the concentration of 22%, collection distance of 10 cm and mandrel diameter of 4 mm. The structure of SF tubular scaffolds before and after ethanol treatment was characterized by FTIR and XRD. After ethanol treatment, the SF tubular scaffolds had a conformation transition from random-coil conformation to Silk II conformation.
Preparation and Magnetic Properties of BiFeO3 and NiCuZn Ferrite Multiferroic Composites
Authors: Qi Xi Wei , Zhang Xiao Yan , Wei La Yi , Sun Gui Fang , Qi Jian Quan
Published: March 2013

A series of xBiFeO3-(1-x) NiCuZn ferrite multiferroic composites have been prepared by solid state reaction method, in which x is 0.1, 0.3, 0.5, 0.7, 0.9 and 1.0. Composites are densified at 700 °C for 3 h. XRD results show that ferroelectric phase and ferromagnetic phase can be co-existed in the composites. The density of composites increases with an increase of BiFeO3content. SEM results reveal that the bigger grains are BiFeO3and the smaller grains are NiCuZn ferrite. Composites exhibits the typical magnetic hysteresis loops. Increasing x, the saturation magnetization of composites linearly decrease. The real part of permeability for composites decreases with increasing x. Meanwhile, the peak of imaginary part of permeability shifts toward higher frequency.
Progress on Internal-Tin Route Nb3Sn Superconducting Strand for ITER in China
Authors: Liu Jian Wei , Zhang Ke , Li Jian Feng , Liu Sheng , Tang Xian De , Du She Jun , Liu Xiang Hong , Feng Yong , Zhang Ping Xiang
Published: March 2013

Multi-filamentary Nb3Sn strand for ITER has been successfully fabricated by a conventional internal-tin (IT) route at Western Superconducting Technologies, Co. Ltd. All the performances of the IT Nb3Sn strand is able tomeet the ITER specifications. In 2010, one hundred kilograms of IT Nb3Sn strand has been cabled, jacketed and integrated into conductor sample titled with TFCN2 by ASIPP in China and tested in CRPP, Switzerland. After 1200 cycles warm-up and cooling down, Tcs of the TFCN2 Sultan sample at 10.78 T, 4.5 K are 6.35 K for the left leg and 6.37 K for the right leg, respectively, which is larger than the ITER lower limit of 5.7 K. This is the first successful Sultan sample made of Chinese Nb3Sn strand. In 2011, the influence of applied axial strain on critical current (Ic) was investigated using TFCN2 strand in the University of Twente, the Netherland. The irreversible degradation of Ic starts around +0.23% tensile intrinsic strain. The heat treatment influence of the duration at 650 °C on microstructure and performance was also studied. It was found that the fraction of un-reacted Nb after heat treatment is dependent on the position in the cross section. The hysteresis loss increases much faster than Ic when the duration at 650 °C increased.
Magnetization Method Design of Bulk Multi-Seeded High Temperature Superconductors
Authors: Jing Hai Lian , Zheng Jun , Liao Xing Lin , Deng Zi Gang , Chen Xin , Yen Fei , Li Jing
Published: March 2013

The potential application of bulk high temperature superconductor (HTS) magnets has attracted much attention because of the potential high trapped flux in HTS magnets. This paper focuses on the magnetization method design of bulk multi-seeded HTS magnets for obtaining their better flux-trapping performance. Firstly, three different magnetization methods were carried out based on the current experimental setup to find a better way of magnetizing a bulk melt-texture three-seeded YBaCuO superconductor. The experimental results indicated that when the three domains of this three-seeded YBaCuO bulk were magnetized in order, the maximum trapped flux was higher than that when only one domain was magnetized. However, this method costs about three times of the magnetization time than the other two methods and the increasing ratio was only about 11.11%. It has been found that another method of magnetizing only the middle domain could also get a good result such as the uniformity of trapped flux is good. In order to improve the current experimental magnetization conditions for further improvement, two sheets of iron were designed to attach two poles of the electromagnet (Lakeshore, Model EM4-CV) for increasing the magnetizing area, and that all domains of a bulk multi-seeded HTS can be magnetized in one time. Firstly, the appropriate size and thickness of the iron sheets was simulated and optimized by Comsol Multiphysics. It has been found that the magnetic field between two poles was highest when the thickness of iron was 2 mm and the length was 68 mm. Then, the simulating and optimization results had been verified by the following experiments. According to the comparison experiments, it is proved that to choose the magnetization method that only magnetizing the middle domain with the improved setup is helpful to obtain larger and more homogeneous magnetic flux for the bulk multi-seeded HTS magnet due to the added iron sheets.
Effects of Interaction of (NaPO3)6 and NaH2PO4 on Ca/P of MAO Bio-Ceramic Coating of ZK60 Mg Alloy
Authors: Du Cui Ling , Chen Jing , Cao Bin Bin , Xu Lei , Lu Sheng
Published: March 2013

Micro-arc oxidation (MAO) process was conducted on ZK60 Mg alloy in a basic biologic electrolyte composed of silicate by addition of (NaPO3)6and NaH2PO4. The microstructural evolution, phase composition and in vitro corrosion resistance of the coating were investigated by means of scanning electron microscopy (SEM) coupled with an energy dispersive spectrometer (EDS) and X-ray diffraction (XRD). The results revealed that bioactive elements Mg, Ca, P and Si were remained in the bio-ceramic coating which can be prepared in suitable biologic electrolyte. For the interaction of (NaPO3)6and NaH2PO4, the Ca/P molar ratio of the coating in the optimized biologic electrolyte reached to 1.24 by L9(34) orthogonal experiments. Compared with the bare ZK60 Mg alloy, the corrosion resistance of the optimized sample in 37 Ringers solution was improved by 4 orders.
The Influence of High-Energy Ball Milling and Sintering Process on the Microstructure and Mechanical Properties of Al-Ni-Y-Co-La Alloy
Authors: Yuan Y.B. , Zheng Rui Xiao , Ge Su Jing , Yang Han , Ma Chao Li
Published: March 2013

Al86Ni7Y4.5Co1La1.5 (at.%) alloy powder was produced by argon gas atomization process. After high-energy ball milling, the powder was consolidated and extruded by using vacuum hot press sintering under different process conditions, sintering temperature, extrusion pressure, sintering time, etc.. The microstructure and morphology of the powder and consolidated bulk alloy were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The phase transformation of the powder was investigated by differential scanning calorimetry (DSC). Mechanical properties of the consolidated bulk alloy were examined. The results showed that as the milling time increase, the volume fraction of amorphous materials and the hardness and yield strength of the bulk alloy were obvious improved.
Effect of Severe Plastic Deformation at Ambient Temperature on Microstructures and Mechanical Properties of Aluminum Alloy 2519
Authors: Liu Ying , Cheng Ruo Lin , Wang Jing Tao , Zhang He , Zhang Xin Ming
Published: March 2013

The effect of severe plastic deformation at ambient temperature on microstructures and mechanical properties of aluminum alloy 2519 was investigated by means of tensile test, micro-hardness test, optical microscopy and scanning electron microscopy. The results showed that tensile strength of as-queched 2519 alloy was greatly enhanced to nearly 550MPa (ultimate tensile strength, UTS) and 520MPa (yield strength, YS) by severe cold rolling or equal channel angular processing (ECAP) while the elongation decreased to 5%. The 2519 alloy could obtain quite well mechanical properties as much as 80 % and 12 passes cold rolling deformation. This indicated that pre-deformation by ECAP is effective in improving the mechanical properties of 2519 alloy by grain refinement, strain aging and high density dislocations.
Microstructural Characterization of an Al-Mg-Si Aluminum Alloy Processed by Equal Channel Angular Pressing
Authors: Zhang Zhen , Liu Man Ping , Yu Ying Da , Skaret Pål C. , Roven Hans Jørgen
Published: March 2013

In the present work, a peak-aged 6061 Al-Mg-Si aluminum alloy was subjected to equal channel angular pressing (ECAP) at 110 °C. The microstructure of the sample was characterized by high-resolution transmission electron microscope and weak-beam dark-field method. It was shown that the dislocation density in some local areas is much lower than the average dislocation density expected in the usual alloys processed by severe plastic deformation. High-resolution transmission electron microscope observations indicated that many full dislocations were dissociated into partial dislocations connected by stacking faults. In addition, a Z-shaped defect (i.e., a type of dislocation locks) probably formed by the reactions of the partials in different {111} planes was first observed in the ECAPed alloy. Furthermore, the precipitation behavior and sequence in the present ECAPed sample were identified by high-resolution transmission electron microscopy.
Indentation Stress Relaxation Behavior in As-Deposited and Rolling Nanocrystalline NiFe
Authors: Cao Z.H. , Meng Xiang Kang
Published: March 2013

The stress relaxation behavior of as-deposited and rolling nanocrystalline NiFe alloy was studied by nanoindentation tests. The results indicated that both the hardness and activation volume of rolling NiFe are larger than that of as-deposited samples. Furthermore, the hardness decreases with increasing indentation depth. The reduction of indentation stress during holding becomes much faster with decreasing the indentation depth. Dislocation density is remarkably enhanced by rolling deformation, leading to the hardening behavior. Dislocation multiplication and accumulation mediated process is believed to the dominant plastic deformation mechanism.
Interfacial Assembly of Two Gemini-Type Schiff Base Amphiphiles with Aromatic Spacers in Organized Molecular Films
Authors: Wang Feng Yan , Jiao Ti Feng , Zhang Qing Rui
Published: March 2013

Gemini amphiphiles have been widely investigated in many aspects due to the unique structure. In this study, two gemini-type Schiff base amphiphiles containing aromatic spacers were synthesized and characterized in Langmuir-Blodgett films. Both compounds formed stable multilayer films and showed distinct phase behaviours on water surface and ion subphase. When the compounds spread on Cu (II) ions subphase, an in-situ coordination occurred for both ligands. While spectral measurements confirmed the coordination with Cu (II) ions and aggregation mode, the morphological investigations showed the distinct nanostructures and molecular rearrangement depended on the molecular spacers and aggregation modes. For both process, the aromatic spacers in gemini amphiphiles have predominant effect in regulating the aggregation modes and spectral changes in organized molecular films.
Hydrothermal Synthesis and Photoluminescence of Pre-Perovskite Lead Titanate Nanofibers
Authors: He Jun Hao , Xu Gang , Wei Xiao , Ren Zhao Hui , Shen Ge , Han Gao Rong
Published: March 2013

Pre-perovskite PbTiO3 nanofibres were synthesized by hydrothermal method with four butyl titanate ((C4H9O)4Ti) and lead nitrate (Pb (NO3)) as the main precursors and Tetramethylammonium Hydroxide (TMAH) as mineralizer. X-ray diffraction (XRD), Raman, Scanning Electronic Microscopy (SEM), Transmission electron microscopy (TEM), high-resolution TEM (HRTEM), and the corresponding selected area electron diffraction (SEAD) were used to characterize the crystal structure and morphology of the obtained products. The results showed that the nanofibers are of a few to tens micrometer at length size, and 50~300 nm at diameter size. Based on the experimental results, the effect of Tetramethylammonium Hydroxide (TMAH) was simply discussed.
Effect of Different Factors on Falling Process of Melt Electrospinning Jet
Authors: Liu Yong , Liu Zhao Xiang , Deng Liang , Wang Ke Jian , Yang Wei Min
Published: March 2013

The falling process of melt electrospinning jet is different from those of solution electrospinning in which there is apparent solvent volatilization. In order to study the factors influencing on the forming process of fibers in melt electrospinning, dropping process of fibers is recorded and analyzed via high speed video camera in the article. Results showed that there was an optimal spinning temperature for melt electrospinning of the polymer; the greater the voltage was, the more obvious stretching action on jet was. However, the voltage did not exceed a certain value, because there was a spinnable voltage limit corresponding to every receiving distance. When the spinning distance was generally short, the jet swinging radius decreased with increasing spinning distance; when the spinning distance was long, the jet was subject to the influence of the environment temperature easily. The changes of viscosity had dominant influence on the motion of jet.
Instability and Pattern Formation of Thin Liquid Films Sandwiched between Soft Elastomer Layers
Authors: Qiao Ling , Tan Fu Ying
Published: March 2013

The surface instability of trilayer films consisting of a fluid layer sandwiched in between the two thin elastomer capping layers was studied. The solid-liquid-solid sandwiched films will form well-defined periodic surface buckling spontaneously. In the present study, the flow of the sandwiched liquid layer was approximated by the theory of lubrication. The elastic capping films was modeled with the nonlinear theory of a thin plate. A linear stability analysis identified the growth rate and the critical wave number of the surface undulation of trilayer films. The analysis showed that applied deformation in the capping layers regulated the surface buckling and resulted in well-defined periodic surface corrugation with tunable wavelength. The result of this study may provide a mechanism to control the morphology of the films in a mechanical way.
Design of Quasi-Planar Ridge SOI Waveguide Resonator for Integrated Optical Gyro
Authors: Wang Kun Bo , Feng Li Shuang , Dong Zheng Fang
Published: March 2013

In order to realize the opto-electronic integration of optic gyro, the quasi-planar ridge SOI waveguide resonator is proposed due to its low loss and small bend radius. First, the single mode condition and smallest bend radius were simulated by using the 3-dimension finite difference beam propagation method (3-D BPM). Then the relationship between the sensitivity of gyro and the resonator characteristics, such as radius and coupling coefficient, was analyzed by applying the model of the integrated optical gyro. Based on these simulations, the ridge height and width of the waveguide were 220 nm and 1.2 μm respectively and the smallest bend radius was 600μm. It is shown that the theoretical detection limit of the gyro was 0.031 °/s when the resonator diameter was 5cm and the couplers splitting ratio was 46.7:53.3. This gyro system is suitable for tactical and civil applications.
Hierarchical Porous TiO2 Fibre Synthesized by Cotton Template and its Photocatalytic Performance
Authors: Liu Cheng Bao , Chen Feng , Chen Zhi Gang , Qian Jun Chao
Published: March 2013

Hierarchical porous TiO2 fibre was successfully synthesized using cotton as template. Microstructures of product were characterized by Field Emission Scanning Electron Microscope (FESEM), nitrogen absorption-desorption technique and transmission electron microscopy (TEM). Titanium oxide material was characterized by repetitious networks consisting of the fibres with diameter of ca. 3-8 μm. The results showed that the products were composed 2-5 nm piled pores stacked by polycrystalline TiO2 nanoparticles. The small crystallite diameter (6-10 nm) and the high specific surface area (83.7 m2·g-1) of sample was believed to be resulted from wide-angle X-ray Diffraction (XRD), high resolution TEM (HRTEM) and the BET method. While the concentration of methylthionine chloride solution was 20 mg/L, catalyst amount 0.1 g/L, the reaction had a higher decoloring rate following irradiation with a UV light source, the decoloring rate can reach over 100% after 250 min.
Effect of Filler Ratio on Properties of Nanohydroxyapatite/SiO2 Based Bioactive Dental Resin Composites
Authors: Liu Feng Wei , Hu Jing Hang , Wang Rui Li , Pan Ying Ying , Jiang Xiao Ze , Zhu Mei Fang
Published: March 2013

Hydroxyapatite (HAP), as an essential component of bone and tooth, is one of the promising bioactive materials. The purpose of this study was to investigate the effects of incorporation of nanoHAP and SiO2 particles on the properties of bioactive dental composite. Silanized HAP and SiO2 were mixed with BisGMA/TEGDMA (1/1 wt/wt) monomers at various HAP/SiO2 mass ratios of 0:7 (no HAP), 5.25/1.75, 3.5/3.5, 1.75/5.25, 7:0 (no SiO2) to yield a series of pastes all containing 70 wt% filler loading. The results showed that flexural strength, elastic modulus and compressive strength gradually decreased with increasing amount of HAP particles, as well as curing depth and polymerization shrinkage, which resulted from the nature of HAP particle material. Water sorption and solubility in water increased slightly with addition of HAP particles. Degree of conversion test could support results above well. Remineralization test in SBF demonstrated dental composite with HAP particles had a good apatite-forming ability. Consequently, dental composite filled with lower amount of nanoHAP (HAP/SiO2 around 0.25) particles would possess better comprehensive performances.
Preparation and Properties of Nanocomposite Hydrogel by Photoinitiated Polymerization
Authors: Xia Meng Ge , Liu Sheng , Wang Yi Heng , Zhang Yan , Wu Yong Tao , Zhu Mei Fang
Published: March 2013

A novel hybrid hydrogel (SAT gel) based on covalent crosslinking was prepared by photoinitiated polymerization. Photoactive polystyrene (PS) nanoparticles were successfully synthesized by grafting photoinitiator 2-[p-(2-hydroxy-2-methylpropiophenone)] ethylene glycol methacrylate (HMEM) onto the surface of PS nanoparticles, and characterized by nuclear magnetic resonance (NMR), fourier transform infrared spectroscopy (FTIR), high resolution transmission electron microscope (HRTEM) and dynamic light scattering (DLS). In the presence of monomer (AAm), PS nanoparticles acting as multifunctional cross-linking agents, and in-situ polymerization was carried out on the surface of photoactive particles. This study focused on the effect of photoactive PS nanoparticles concentration and illumination time on the morphology and swelling behavior of SAT hydrogels. It revealed that the three-dimensional structure and swelling ratio decreased with the increasing concentration of PS nanoparticles. Moreover, the pore size compressed with extending the illumination time. Embedding photoactive nanoparticles into hydrogels network to prepare novel hydrogels had advantages of controllable polymerization process and short forming time. This method provided a new way to prepare soft materials and to design the intelligent hydrogels.
Influence of Titanium Sol on the Sintering Behaviour, Microstructure and Properties of Al2O3-SiO2 Ceramic Cores
Authors: Chen Jun , Zhang Yue
Published: March 2013

A series of Al2O3-SiO2 ceramic cores with titanium sol sintered at 1350, 1450, 1500 and 1550for 2h, respectively, were prepared, and the phase and microstructure were characterized by X-ray Diffraction and Scanning Electron Microscopy. The influence of titanium sol on the phase transformation, shrinkage rate and flexural strength at room temperature has been investigated. The mullite phase formation temperature decreased by at least 150with the addition of 1wt% to 5wt% TiO2. Additionally, the titania additive promoted the combination of Al2O3 and SiO2, producing mullite phase which reduced the shrinkage and improved the flexural strength.
The Process Condition Research of SrAl2O4:Eu2+,Dy3+ Luminous Powder by Microwave Method
Authors: Wang Hai Feng , Ma Yu Bing , Lao Yan Feng , Lu Meng Chen
Published: March 2013

The luminescent material, composed of rare-earth-doped alkaline earth aluminate, has been paid wide attention because of its chemical stability, usability and non-radioactive. In this study, the luminous material SrAl2O4:Eu2+,Dy3+ was prepared by a microwave method. The effect of microwave parameters on the performance of the luminous powder was investigated. The excitation and emission spectrum of the luminous material were measured by fluorospectrophotometer. The phase composition of the powder was analyzed by XRD. The results show that the luminous powder can be synthesized only when the microwave power is higher than the med-high fire (640W). The sample has the best luminous property when the molar ratio of Sr (NO3)2:Al (NO3)3·9H2O:H3BO3:Eu (NO3)3·6H2O:Dy (NO3)3·6H2O is about 1:2:0.5:0.04:0.08, and it is processed by high power for 20min in microwave oven.
Preparation of ZrSiO4/C Inclusion Pigments by Nonhydrolytic Sol-Gel Methed Combined with the Process of Carbon Black Modification
Authors: Jiang Wei Hui , Feng Yong , Liu Jian Min , Zhu Qing Xia , Xu Xia Yi
Published: March 2013

nclusion pigments of ZrSiO4/C were prepared by nonhydrolytic sol-gel (NHSG) method combined with the process of carbon black modification. The crystalline phases, microstructure, functional groups on the surface of carbon black and chromatic value of the pigments were characterized by XRD, TEM, FTIR and Colorimeter, respectively. The surface structural changes of the carbon black modified by nitric acid and the influences of process parameters on the chromatic value of the pigments were also investigated. The results show that the process of carbon black modification enhances the affinity and binding force between carbon black and ZrCl4 sol, which contributes to improve the effect of carbon black wrapped by ZrSiO4. The ZrSiO4/C inclusion pigment were obtained after calcining at 1000 °C for 8 h, and the L*, a* and b* value is 53.88, 0.74, and 1.88, respectively.
Antimony-Doped SnO2 Nanoparticles with Controlled Doping Level via Nonaqueous Sol-Gel Procedure
Authors: Wu Jun Yan , Chen Fei , Shen Qiang , Zhang Lian Meng
Published: March 2013

Antimony-doped tin oxide (ATO) nanoparticles with controlled doping level were prepared by a nonaqueous solution route, using alcohol as the solvent, citric acid as an agent, tin (IV) tetrachloride as tin source and antimony (III) chlorideas as antimony sources. As-synthesized samples were characterized by Thermogravimetric analysis (TGA), powder X-ray diffraction (XRD), transmission electron micrographs (TEM), N2 adsorption-desorption isotherms, and X-ray photoelectron spectroscopy (XPS). The results showed that the content of citric acid was the most important processing parameter which was largely governing the reaction course and the complete incorporation of Sb. When the citric acid to metal mol ratio was 2, the particles were the highly crystallized ATO nanoparticles of about 20nm and the Sb atoms were indeed incorporated into the SnO2 crystal structure (cassiterite SnO2).
Effect of Gelation Process on Preparation of Aluminum Titanate Ultrafine Powder by Hydrolytic Sol-Gel Method
Authors: Jiang Wei Hui , Zhang Quan , Liu Jian Min , Zhu Qing Xia , Miao Li Feng
Published: March 2013

Aluminium titanate (AT) ultrafine powder was prepared via hydrolytic sol-gel (HSG) method using aluminium nitrate (Al (NO3)3·9H2O) and titanium tetrachloride (TiCl4) as precursors as well as ethanol as solvent. Water required for hydrolysis reaction was supplied by the crystal water of aluminium nitrate itself. The effect of gelation processes, i.e. reflux and solvothermal treatment, on synthesis of AT powder was investigated by means of DTA-TG, XRD, SEM, and TEM, etc. The result shows that the gelation process has significant effect on the synthesis of AT powder. By reflux process, AT powder was synthesized at 1350 °C with average particle size above 1μm and serious agglomeration. Through solvothermal treatment process, however, AT powder with average particle size less than 150 nm was prepared at 1050 °C at a relatively high synthesis rate, which is due to the refinement reactants by the solvothermal treatment.
Effect of Ni on Microstructure and Mechanical Properties of Bulk Nanocrystalline Fe-Al Based Alloys Prepared by Aluminothermic Reaction
Authors: La Pei Qing , Wei Yu Peng , Yang Yang , Wang Hong Ding , Bai Ya Ping
Published: March 2013

Bulk nanocrystalline Fe-Al based alloys with 5, 10 and 15 wt. % Ni were prepared by aluminothermic reaction. The alloys were analyzed by electron probe microanalyzer, X-ray diffraction and transmission electron microscope. Compressive yield strength and hardness of the alloys were tested. The experimental results showed that all of the alloys consisted of Fe-Al-Ni matrix and small amount of Al2O3 sphere. The matrix phases of the alloys with 5 and 10 wt. % Ni had disordered α-Fe solid solution, while the matrix phases of the alloys with 15 wt. % Ni had disordered α-Fe solid solution, NiAl phase and Fe3AlCx phase. Average grain sizes of the matrix phases of the alloys were about 20 nm. The alloys with 5 wt.% Ni had the best plasticity, but the alloys with 15 wt. % Ni had the highest yield strength and hardness. Yield strength of those alloys is higher than that of coarse-grained Fe3Al.
Fabrication Technique of Wide Nb42Ni40Co18 Amorphous Alloy Ribbons with High Melting Temperature
Authors: Ding Hong Yu , Zhang Wei , Yao Ke Fu
Published: March 2013

In this paper, the effects of the processing parameters on the preparation of Nb42Ni40Co18 amorphous alloy ribbons were analyzed in detail, including the property of the alloy, material and size of the injection nozzle, setting of the alloy ingots, the distance between the nozzle and the copper wheel, surface quality and velocity of the copper wheel, heating rate and time, injection pressure, injection time, etc. Finally key factors for preparing wide Nb42Ni40Co18 amorphous alloy ribbon have been proposed.
Fabrication of Zr55Al10Ni5Cu30 Amorphous Composite Coating on Plain Carbon Steel by Laser Cladding and Remelting
Authors: Jia Gao Zhi , Wang Wen Xian , Liu Xu , Cui Ze Qin , Xu Bing She
Published: March 2013

A Zr-based amorphous composite coating was fabricated by laser cladding and remelting on plain carbon steel. The amorphous phase contents of coatings were tailored by controlling the power density. The effect of amorphous phase content along the depth direction on the microhardness and corrosion resistance of the coating was studied. The results showed that the content of amorphous phase significantly decreased from the remelted layer to the cladded layer. In addition, it was found that the maximum microhardness of the coating were about 1061 HV0.1, observed 200 μm beneath the surface. Potentiodynamic polarization studies in 3.56 wt.% NaCl solution indicated that the remelted layer exhibited excellent corrosion resistance due to the high amount of amorphous phase.
Bio-Properties of Zr-Based BMGMC as Potential Hard Tissue Implants
Authors: Huang Xiao Bo , Lin Nai Ming , Hang Rui Qiang , Tang Bin , Qiao Jun Wei
Published: March 2013

In this study, an in situ formed bulk metallic glass matrix composite (BMGMC) (Zr58.5Ti14.3Ni4.9Cu6.1Nb5.2Be11.0) was synthesized. Bulk metallic glass (BMG) (Zr52.5Cu17.9Ni14.6Al10.0Ti5.0) was also included in this work and a Ti-6Al-4V alloy was used as a reference material. Due to the glassy matrix that postpones the growth of corrosion pits, the BMGMC displays high positive corrosion potentials and low corrosion current densities. The BMGMC exhibited a higher improved corrosion resistance than the Ti alloys. Furthermore, the biocompatibility of this BMGMC was assessed by studying the cellular behavior of bone-forming mouse M3T3-E1 pre-osteoblast cells. The matrix did not significantly affect cell adhesion, proliferation and ALP activity. The general biosafety of Zr-based BMGMC for M3T3-E1 cells was revealed as normal cell responses. Zr-based BMGMC shows great potential for applications in the hard tissue implants.
Soft Magnetic Properties of the Fe76Si9B10P5/Zn0.5Ni0.5Fe2O4/PVA Composite Film
Authors: Chen Sheng , Wang Ming Gang , Zhao Zhan Kui
Published: March 2013

The Fe76Si9B10P5/Zn0.5Ni0.5Fe2O4/PVA composite film was fabricated by the spin-coating process. To improve the dispersibility and compatibility of Zn0.5Ni0.5Fe2O4nanopaticles, Bis (P, P-bis-ethylhexyl diphosphato) ethanediolato titanate was used as the surface modifier to deal with Zn0.5Ni0.5Fe2O4nanoparticles. The micro morphology and magnetic properties of the composites was observed respectively by 3D Measuring Laser Microscope OLS4000 and MATS type auto test system of magnetic materials. Several contrast groups using by the similar preparation process showed that surface modification on the Zn0.5Ni0.5Fe2O4nanoparticles did not only improve the dispersibility of Fe76Si9B10P5amorphous alloy particles presenting in the PVA, but also improve the softmagnetic properties of the composite films; the magnetic properties of the composite film containing Zn0.5Ni0.5Fe2O4nanoparticles performed better than the one that not contain Zn0.5Ni0.5Fe2O4nanoparticles; the permeability of the film increased with the increasing of the contents of Fe76Si9B10P5amorphous alloy powder in the composites.
Fabrication of VO2 Film in the Spin-Coating Way
Authors: Jiang Guo Jian , Yao Shu Ping , Liu Yun Ying , Xu Jia Yue , Shen Hui , Jin Min , Peng Gui Hua
Published: March 2013

VO2 thin films were obtained from V2O5 thin film in the thermal decompose process. V2O5 thin films were prepared in the spin-coating way and with V2O5 sol-gels as raw materials fabricated by the reformative inorganic sol-gel method. The effects of the viscosity of colloid on the fabrication of V2O5 film and the thermal decomposing temperature on the fabrication of VO2 film were studied. The results show that the appropriate viscosity of colloid to obtain well-distributed V2O5 film was in the range of 30g/L-40g/L and suitable thermal decomposing temperature was about 500°C.
Room Temperature Brittlement of T2 in the Mo-Si-B System
Authors: Pan Kun Ming , Zhang Lai Qi , Du Wei , Lin Jun Pin
Published: March 2013

Compression and three-point bending tests were conducted at room temperature (RM) on the Mo5SiB2 (T2) alloy, which was prepared by sparking plasma sintering (SPS). It was found that almost no plastic deformation occured in the T2 alloy before failure but with a tremendous compressive strength of 2907 MPa. The fracture toughness determined from the single edge notch bend specimen is 3.34 MPa·m1/2, similar to the value of 3.5 MPa·m1/2 in ɑ-Al2O3. Once the cleavage crack initiated near the notch under continuous loads, it propagated on a certain plane (001) until the specimen completely fractured. In this work, the electronic structure was also calculated by the first-principles method, indicating that the contribution to RM brittleness is mainly caused by the covalent bonds which arrange alternately in the T2 phase.
Microstructure and Mechanical Properties of TiAlNb Coating Deposited by APS and HVOF Spraying
Authors: Zeng Hong Jie , Zhang Lai Qi , He Xin Yu , Zhang You Cha , Jia Pen , Lin Jun Pin
Published: March 2013

As a material intended for application in hot-dip galvanization, Ti28.15Al63.4Nb8.25Y (at %) coatings were deposited onto 316L stainless steel substrate using high velocity oxygen fuel (HVOF) and atmospheric plasma spray (APS), respectively. The influence of different thermal spraying techniques on the microstructure, phase transformation, porosity, bond strength and hardness values of Ti28.15Al63.4Nb8.25Y coatings was analyzed by scanning electron microscopy (SEM), X-ray diffraction, tensile test and other analysis methods. In addition, the thermal shock test of Ti28.15Al63.4Nb8.25Y coatings was carried out to evaluate the desquamation resistance and the model of invalidation. The results indicated that HVOF Ti28.15Al63.4Nb8.25Y coatings had more uniform and compact morphology than APS Ti28.15Al63.4Nb8.25Y coating and HVOF Ti28.15Al63.4Nb8.25Y coatings have lower porosity and oxide content. The coatings processed by HVOF had higher bond strength, microhardness and thermal shock resistance and displayed better mechanical properties than that prepared by APS.
The Effect of Stoichiometry and Degree of Order on Mechanical Properties of Ni3Fe Intermetallics
Authors: Chen Ye Xin , Qian Hai Yan , Chen Tao
Published: March 2013

The effects of Fe stoichiometry and degree of order on mechanical properties of intermetallics Ni3Fe were investigated. The experimental results showed that the phase composition and the grain size of Ni3Fe alloy was independent on Fe stoichiometry. The Ni3Fe alloy with the normal stoichiometry had the lowest elongation in the ordered and disordered alloys. The tensile strength of Ni3Fe alloy depended on Fe stoichiometry of alloy. The effect of Fe stoichiometry on the mechanical properties of the ordered alloy was larger than that of disordered alloy. There were more point defects in lattice when the alloy stoichiometry deviating from the normal stoichiometry in the Ni3Fe alloy. The changes of the concentration of the point defects and degree of order altered the deformation behavior of the Ni3Fe alloy.
Processing and Microstructures of δ-Al2O3/ AE44 Composite Synthesized by SS-HPDC
Authors: Li Li , Li De Jiang , Zeng Xiao Qin
Published: March 2013

A cylinder block with δ-Al2O3/AE44 (Mg4.0Al4.1RE0.3Mn) magnesium matrix composite was manufactured by Slow Shot High Pressure Die Casting (SS-HPDC) technique. The temperature and wall thickness of the fiber added affect its formation. The block is not infiltrated well when the temperature of the preform is below 450°C. Micro-cracks occur if the thickness of the preform is larger than 8.625mm. Microstructures in the AE44 alloy with and without δ-Al2O3 fibers (Saffil) were both investigated by means of X-ray diffraction (XRD), optical microscopy (OM) techniques and scanning electron microscopy combined with energy dispersive spectrometry (SEM-EDS) equipment. The results show that many Al-RE intermetallic compounds present not only in the matrix but also in the composite, although the grain sizes, the concrete types and their distribution differ. Al-RE second phases in AE44 appear around the grain boundaries in large quantities mainly in globular, lamellar and acicular shape but few in particulate shape, while most of them grow on the fibers in small whiskers and only few scatter in the matrix. Meanwhile, the appearance of Mg2Si in the composite may account for the interfacial reaction between the binder in the preform and the matrix alloy.
Deformation and Workability Evaluation of GW103K Magnesium Alloy in Hot Compression
Authors: Yu Ran Xu , Wang Shi Yi , Tang Qiong , Zeng Xiao Qin
Published: March 2013

Gleeble 3500 thermo mechanical simulator was used to perform hot compression tests of GW103K (Mg-10Gd-3Y-0.6Zr) magnesium alloy at a temperature range of 573K-723K and strain rates of 0.001-1. The workability of the alloy can be evaluated by means of processing maps on the basis of dynamic materials model (DMM) and the superior processing condition is selected. Combining true compression stress-strain curves with the results of microstructure observation, it was found that the peak stress decreased observably as the decrease of strain rate and the increase of deformation temperature. Constitutive equation is built to reveal the accurate relationship among flow stress, temperature and strain rate.
Microstructures and Mechanical Properties of a New Biomedical Material Mg-13Li-X Alloys
Authors: Zhang Yan Chang , Luo Sha , Zhang Qing Qing , Xu Xiao Qing , Zhou Tie Tao
Published: March 2013

In this paper, a new biomedical Mg-Li alloy for the improvement of the comprehensive mechanical properties by micro-alloying and processing to meet the need of mechanical properties of biomedical materials. And the Mg-Li (Mg-Li-Al-Zn-Ca-Sr) alloy's processing and heat treatment were investigated in detail. The crystal texture of cast state, forged state and rolled state were observed and analyzed by OM, XRD and SEM. The mechanical properties of every stage were tested as well. The results showed that the grain size was refined obviously by the concentrating of Ca and Sr in the grain boundary. With the increase of rolling lane, the second phase's distribution was changed to a scattered state gradually from the reunion state. The tensile strength of the forged alloy was improved as well as its elongation after cold rolling and with rolled heat treatment process. The tensile strength reached 220MPa and the elongation reach 22%, which might meet the demand of cardiovascular stents mechanics.
Microstructure and Bonding Strength of AZ91/Al Composite Fabricated by Brazing and Hot-Rolling
Authors: Yang Lin , Zhao De Wen , Zhang Zhong Li , Shan Hong Liang , Yang Lin , Liu Zheng
Published: March 2013

In order to achieve the composite of the AZ91 magnesium alloy and pure aluminum sheet, Zn-Sn-Al solder as compound agent, electric arc plating was employed to spray the brazing solder on the surface of AZ91 and pure Al sheets. The sheets were then subjected to heat treatment at 420 for 10min before rolling lamination at a reduction of 10%. The as-rolled sheets were annealed at 390 for 4hours. The microstructure, phase constitution and bonding strength of the composite interface were tested and analyzed by using SEM and energy dispersive scope (EDS), x-ray diffraction and tensile test. Experimental results showed that, under the atmospheric environment, AZ91/Al composite can be successfully fabricated with Zn-Sn-Al solder by brazing and hot-rolling, and the shearing strength can reach 22.46MPa. After annealing for 4 hours, a diffusion layer composed mainly of Al and Zn elements was formed near Al matrix, and the intermetallic phases were MgZn2 and Mg2Sn which was the same to the phases at the interface of AZ91/Al composite without annealing, but the amount was relatively higher. The interfacial fracture of composite was mainly due to the existence of intermetallic phases.
Microstructures and Mechanical Properties of Mg-8Al-1Nd-0.5Zn-xSr Alloys
Authors: Shi Bao Liang , Luo Tian Jiao , Liu Rui Dong , Dong Xu Guang , Wang Jing , Yang Yuan Sheng
Published: March 2013

The influence of trace strontium (Sr) addition on the microstructure and mechanical properties of Mg-8Al-1Nd-0.5Zn was investigated with OM, SEM, and XRD etc. The results show that the lamellar eutectics and divorced β-Mg17Al12 were reduced or refined with trace Sr addition. Among the as-cast Mg-8Al-1Nd-0.5Zn-xSr alloys, the Mg-8Al-1Nd-0.5Zn-0.05Sr alloy exhibited the best mechanical properties in which the tensile strength, the yield strength reached to 244.9 MPa and 111.7 MPa respectively. In addition, with the increase of Sr addition, the ductility was improved and it was observed that the number of cleavage steps and secondary cracks decreased on the fracture surfaces of tensile samples. It was also observed that the fractures occurred in the coarse β-Mg17Al12 phase instead of the Mg/Mg17Al12 interface or Al11Nd3 phase.