bluuebunny/crossref_metadata_2025 huggingface dataset:
Electroless Ni-P Plating on Mg-7Al Alloy by Chemical Conversion Pretreatment
Authors: Jia Su Qiu , Guan Jing Xin , Qiu Jing Dong , Chen Hua , Jia Shu Yan
Published: March 2013

Electroless Ni-P plating on Mg-7Al alloy by chemical conversion pretreatment was investigated. Morphology of electroless nickel plating coatings and phase compositions were measured by SEM, EDX and XRD. The optimized bath composition parameters were determined through orthogonal design. The morphology of electroless nickel plating coatings on Mg-7Al alloy exhibits a nodular structure and resembles the surface of a cauliﬂower and the coating is compact and consists of amorphous Ni-P coating. Potentiodynamic polarization curves of the Ni-P coatings in 3.5% NaCl show that the Ni-P coating extensively improves the corrosion resistance of Mg-7Al alloy and the highest corrosion potential reached to -0.54V vs. SCE(saturated calomel electrode). The results of the orthogonal experiment show that Nickel Sulfate of 25 g/L, Sodium Hypopho-sphate of 25 g/L and Citrate 7.5 g/L can be considered as the optimum bath content parameters for electroless Ni–P plating on Mg-7Al alloy and Nickel Sulfate has more effect on corrosion potential than Sodium Hypophosphate and Citrate..
Microstructure and Optical Properties of ZnS:Mn Nanocrystals
Authors: Ma Jin Hua , Wang Chang Zheng , Sun Chang Yong
Published: March 2013

Abstract. By using Na2S•9H2O as source precursor and citric acid as stabilizer, ZnS:Mn nanocrystallines were synthesized by solvothermal method. They were annealed at 800 oC in the charcoal powder. The structure, morphology and optical properties were investigated by using X-ray diffraction spectra (XRD), scanning electron microscopy (SEM), and Spectrofluorophotometer respectively. The results showed that all unannealed ZnS:Mn nanocrystallines were about 3~5 nm of particle size and have cubic structure, and all annealed samples were about 30-70 nm of particle size and have mixed structure of the cubic phase and hexagonal phase. Moreover, Mn2+ took the place of Zn2+ in ZnS:Mn. With the increment of Mn2+ content, there occurred a strong emission peak at about 596nm which can be attributed to the Mn2 + leap from 4T1 to 6A1. In addition, the intensity of 596nm emission peak first increased and then decreased with the increment of Mn2+ content, reaching a maximum at about 15% of Mn2+ content. After annealing Mn2+ emission peak intensity is about 20 times that before annealing, and the luminescence peak also showed slightly blue shift.
Forging Effect of Horizontal V - Shaped Anvil for Heavy Axial Forgings
Authors: Zhang Yong Jun , Liu Zhu Bai , Han Jing Tao
Published: March 2013

Horizontal V – shaped anvil forging method is introduced to control fibrous tissue flow direction through changing shape of anvil, to improve the anisotropy of mechanical properties of forgings. This method can provide effectively drawing out technology for heavy axial forgings with requirements on the transverse mechanical properties. In this paper pilot production for rectangular billet by the forging method with horizontal V - shaped anvil were carried out. The results show that the forging method with horizontal V-shape anvil can improve transverse mechanical properties, realize uniform forging for heavy axial forgings, the ratio between transverse and longitudinal mechanical property is about 1.0 in the same position for heavy axial forgings, and uniformity degree of mechanical properties is better.
Scallion-Root-Shaped GaN Nanorods Grown by Two-Step Method and Study on their Properties
Authors: Cao Yu Ping , Sun Hai Bo
Published: March 2013

Two-step growth technology to successfully synthesize scallion-root-shaped GaN nanorods was presented in this paper. This growth method is applicable to continuous synthesis a large number of single-crystalline GaN nanorods with a high purity at a low cost. X-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) are employed to characterize the structure, composition and morphology of as-grown GaN nanorods. The results show that the obtained nanorods are single-crystal GaN with hexagonal wurtzite structure and have a relatively high purity. The diameter of the nanorods is about 500nm with length up to several tens of micrometers. The representative photoluminescence spectra (PL) measured at room temperature exhibited a strong and broad emission peak at 388nm corresponding to the strong-band-emission in wurtzite GaN, indicating that the nanorods have a good emission property. The growth mechanism is also briefly discussed.
Development of Radial-Axial Ring Rolling Experimental Equipment and Calculation of Ring Rolling Forces
Authors: Tan Yu Long , Wang Qiang , Han Shuang Hui , He Fang
Published: March 2013

By referring to the heavy duty radial-axial ring rolling mill in production, a radial-axial ring rolling experimental equipment was designed and developed. Based on the principle of similarity, the mathematical relationship and calculation method between experimental rolling forces and actual ones in the process of radial-axial ring rolling were established. This experimental equipment has many advantages, such as compact structures, full functions, small deformation and more safety and reliability, which can be used in experimental study and calculation of ring rolling forces.
Impact Analysis of Microstructure Evolution in Hot Rolling of H-Beams
Authors: Liu Wen Ping , Zhang B. , Wang Pei Qi , Zhang Qin He
Published: March 2013

To improve the product properties of H-beams, it is essential to understand the effects of hot rolling parameters on the microstructure evolution of the beams. For this purpose, a thermo mechanical model was built with the finite element Package ABAQUS. By re-meshing the model, multipass large-deformation hot rolling process was simulated under the boundary conditions predefined in accordance with the practical production. Based on the hot rolling simulation, an impact analysis of strain rate, initial rough rolling temperature, and time interval between passes on the microstructure evolution of H-beam austenite was conducted. The analytical results are meaningful for optimizing hot rolling parameters and improving H-beam properties.
Analysis of Linear Defects of Cold-Rolled Galvanized Sheet
Authors: Peng Qi Chun , Yang Jin Ling , Peng Sheng , Zhang Xue Hui , Tang Shu Ping , Tian Yi Sheng
Published: March 2013

Linear defect is a common defect of galvanized sheet. Formation mechanism of linear defect was analyzed by scanning electron microscopy (SEM) and energy disperses spectroscopy (EDS). The results indicate that Al2O3 particles which have a size less than 7μm are enriched in the shallow surface of the substrate. Al2O3 particles are exposed during rolling, resulting in scratches and rough spots on cold-rolled sheet. The places where Al2O3 inclusions enrich are easy to form surface micro-cracks. Linear defects are formed at the places of scratches or cracks during hot dip galvanizing. Optimum measures are putted forward based on Al2O3 inclusions and cracks.
A Mild and Efficient Approach for the Reduction of Graphene Oxide
Authors: Wang Yu Feng , Han Chun Hua , Liu Bao , Zhao Dong Mei , Zhao Dong Yu , Sun Li Guo
Published: March 2013

A mild and efficient approach for the reduction of graphene oxide by NaHTe is reported in this work. This reductant is of low toxicity and nonvolatile and it reduce GO to graphene at room temperature in 2h. X-ray diffraction results showed that NaHTe can reduce GO completely in shorter time, comparing with hydroxylamine. Furthermore, X-ray photoelectron spectroscopy also indicates the reduction of GO to grapheme.
The Numerical Model of Axial Force for 4-High Mill
Authors: Kong Fan Fu , He An Rui , Shao Jian , Chen Chao Chao
Published: March 2013

Axial force is an important affecting factor on the service life of rolls’ bearings. Based on Timoshenko’s deep beam theory and finite difference method, the efficient and accurate roll stack deformation model is built to provide the deformed rolls’ shape and contact stress distribution. And then, the formation mechanism and calculation method of axial force for 4-high mill is presented. By contrasting with the result given by commercial FEA package, the error between ANSYS and home-made program is less than 10%, the accuracy of axial force model is validated.
A Dynamic Observation Concept to Keep Water-Soluble Coolant in Normal Condition for Long Time
Authors: Kondo Yasuo , Yamaguchi Mitsugu , Sakamoto Satoshi , Yamagchi Kenji
Published: March 2013

We propose a dynamic observation concept to pretend aged degradation of water-soluble coolant. The first-hand observation of coolants by a CCD microscope is extremely useful for monitoring the drastic appearance change. The appearance changes of coolant also could be monitored by combining the reflectance changes from the Red, Green and Blue LED lights. The physical process of absorbing light is occurred only at the specific wavelength in the water-soluble coolants. The absorbance at the specific wavelength would become a reliable indicator to predict the controlled condition of water-soluble coolant. Setting up these sensing systems to the machine tools make it possible to observe the coolant dynamically and on real time.
A Visualization Study of Abrasive Flow Variation in Abrasive Air Jets
Authors: Fan Jing Ming , Wang Jun
Published: March 2013

Abrasive jet machining is an efficient technology for the fabrication of three dimensional micro structures on brittle materials. In abrasive jet machining, the variation or fluctuation in the amount of abrasive supply has a significant effect on the quality of the machined structures. An image processing technique is employed in this study to study the abrasive flow rate variation, in which abrasive jet pictures are captured at different moments by a Particle Image Velocimetry technology and then processed using Labview Vision Assistant and MATLAB. It shows that the abrasive flow rate fluctuates with time under the jetting conditions considered. The abrasive flow from larger nozzles or at smaller air pressures shows more profound fluctuation. Although the abrasive flow fluctuation from smaller nozzles remains almost constant when the air pressure is changed, for larger nozzles, the magnitude of the fluctuation gradually decreases as the air pressure is increased.
Dry Machining of T6061 Aluminium Alloy Using Titanium Carbonitride (TiCN) Coated Tools
Authors: Ariff Tasnim Firdaus , Sofian Nur Najwa , Che Mat Nor Hayati
Published: March 2013

In metal cutting process, the use of cutting fluids, cooling and easy chip removal causes long-term effects of cutting fluids disposal into environment. Research has also proven the health hazards on manufacturing workers who coming in direct contact with cutting fluids. Currently it is highly competitive or end-user of metal workings fluid to reduce cost and improve productivity. Considering the high cost and problems associated with health and safety, it would be desirable if the use of cutting fluids be omitted. This study investigates the flank wear behavior of coated Titanium Carbonitride (TiCN) coated tools in dry and wet machining of T6061 Aluminum alloy with the aim of obtaining the optimum cutting speed for dry and wet machining respectively. By using specific depths of cut 0.2 and 0.6 mm with feed rates of 0.4 and 0.8 mm/rev respectively, the wear was investigated for 3 different high cutting speeds; 290, 360 and 446 mm/min. Results of dry machining was compared with traditional wet machining process. The temperature of tool tip, machining time and tool wear were recorded. Wear rate of the tool increases with the increasing cutting speed and parameters for both dry and wet machining. Wear percentage difference for dry machining was found to be 21-37 % (d = 0.2 mm and f = 0.4 mm/rev) and 41 - 58% (d = 0.6 mm and f = 0.8 mm/rev) higher than wet machining. The optimum cutting speed for both cutting parameters is 446 m/min for dry and wet machining. Tool tip temperature for dry machining is found to be 14 - 16 % higher than wet machining for both cutting parameters. It is observed that dry machining is suitable for high speed intermittent cutting operations.
Micro-Channel Fabrication on Quartz Crystals by a Micro Abrasive Air Jet
Authors: Fan Jing Ming , Wang Jun
Published: March 2013

Abrasive air jet micro-machining is a new promising technology for processing brittle material. An experimental study of micro-channeling on quartz crystals using an abrasive air jet is presented. The effect of the processing parameters on the produced channel profile such as the channel width, depth and kerf taper angle is analyzed, along with the effect on the roughness of channel bottom surfaces. Plausible trends of the major process performance measures with respect to the process parameters have been revealed. These trends are useful in guiding the selection of process parameters in practice.
Microgrooving Using an Ultrafine Wire Tool
Authors: Sakamoto Satoshi , Kano Tomonori , Yamaguchi Mitsugu , Arakawa Susumu , Kondo Yasuo , Yamaguchi Kenji , Yakou Takao
Published: March 2013

We examined the slicing technique of silicon wafers with little kerf loss using an ultrafine wire tool. As the first step, we performed microgrooving with an ultrafine wire tool. The thinning of the wafer and the decrease in kerf loss can minimize production costs. We discuss the strength characteristics and the microgrooving performance of the ultrafine wire tool. The main results are as follows. The relative velocity greatly affects the grooving properties. The ultrafine wire tool easily breaks when the relative speed is high. When the ultrafine wire tool and abrasives with large diameter grains are used, the ultrafine wire easily breaks and chipping in the work material easily occurs; furthermore, the ultrafine wire strays.
Study on Arithmetic of Surface Damage Ratio in High Speed Machining of Graphite Based on Matlab Image Processing
Authors: Zhou Li , Li Yu Zhong , Wang Cheng Yong
Published: March 2013

The surface quality of graphite cannot be completely evaluated only by the roughness value Ra measured by profilometer. The surface damage ratio Sc is presented to give quantitative description of surface quality of graphite, which was calculated as the ratio of the projection area of fracture craters to the overall area of free surface. The machined surface was observed and taken photo by use of the stereo microscope with CCD image acquisition system. Matlab image processing tool was used to convert the color photo to binary image, in which fracture craters were shown as black pixels and the other surfaces as white pixels. The surface damage ratio is the result of the sum of black pixels divided by the overall pixels. Under the same conditions of high speed machining experiments for verification, the surface damage ratio was calculated in comparison with the Ra values measured by profilometer. The variation tendency of surface damage ratios exhibited good coherence to the measured roughness.
FEA Simulation of Clinching Process Based on GTN Damage Model
Authors: Shi Bai Jun , Liao Shu Hui , Peng Song , Li Hang
Published: March 2013

In this work, the Gurson-Tvergaard-Needleman (GTN) damage model is adopted to depict the material damage during the clinch joining process in a simulation-based theoretical model. The parameters of the GTN model which influence the void nucleation, growth and coalescence are identified. Their values of a specific material, C45E4 (ISO) steel, have been determined after carefully comparing the simulation results with the real sheet material tensile test. The established GTN damage model parameters are then imported into the simulation model to investigate the material damage during the mechanical clinch joining process. The Finite Element Analysis (FEA) simulation results show promising, because the material’s initial damage position can be located and analyzed. For a given design, the initial fracture point was predicted which is located on the inner side of the clinched joint neck of the upper sheet, which matches with the results of the experimental test very well. It can be concluded that the incorporation of GTN damage model has extend the capability of the simulation model.
Study on a Preparation of PS Hollow Submicro-Fiber by Coaxial Electrospinning
Authors: Liu Tai Qi , Lv Dan , Zhao Xiao Long , Gao Ning , Zhao Na
Published: March 2013

Coaxial electrospinning has been recognized as an efficient technique for fabrication of composite fibers with especial circular cross-section in a diameter from micrometers to nanometers. In this paper, PS hollow submicro-fibers have been successfully prepared by electrospinning two polymer liquids through a coaxial, two spinneret, followed by selective removal of the core. Moreover, the influence of the relative (inner-to-outer) flow rate on the morphology and the average diameter of the fibers have been studied. The hollow submicro-fibers are particularly attractive for use in catalysis, purification, separation, gas storage, energy conversion, drug release, sensing, and environmental protection.
Effect of TiH2 Composition on Porous Stainless Steel and Titanium Hydride Composite Synthesized by Spark Plasma Sintering
Authors: Allabergenov Bunyod , Tursunkulov Oybek , Abidov Amir , Kim Sang Youp , Lee Eun Young , He Li Li , Kim Tae Yong , Jeong Soon Wook , Kim Sung Jin
Published: March 2013

The main aim of this research was to investigate the influence of processing parameters on the me-chanical properties and morphology of porous STS:TiH2 composites made by using spark plasma sintering method. Mechanical parameters and structural analysis of the fabricated composite have been investigated by Rockwell hardness, density tester, optical microscope, XRD and FE-SEM. In particular the porous stainless steel (STS) and titanium hydride TiH2 composites materials with op-timal ratio were prepared with using additional hollow glass microsphere and water glass for con-trolling of the porosity degree. It is found, that the porosity degree depended on addition of TiH2 and hollow glass additive, resulting to modification of the pore shape and size. I was shown that the dispersion of STS/TiH2 composite which sintered by spark plasma sintering method without pressure result to increasing of mechanical properties (hardness and density). According to obtained results, the addition of TiH2 powder into STS improves the mechanical property of the synthesized specimens especially the specimens with addition 20 wt% and 50 wt% of TiH2 demonstrated high hardness values and good density.
Simulation Research on Relieving Welding Residual Stress by Vibratory Stress Relief Technology
Authors: Duan Neng Quan , Li Xiao , Du Wen Hua , Dou Xue
Published: March 2013

Analysis of the causes of welding residual stress and the mechanism of VSR, also give the sufficient condition of the exciting force. Firstly, use the thermal - structural coupling and cell life and death of the welding process simulation, get the welding residual stress. Consistent with the theory. Secondly, build the VSR simulation process based on the use of the harmonic response analysis and welding simulation. select the appropriate VSR process parameters through the simulation results. Finally, VSR process simulation, analysis showed that the peak of residual stress after VSR treatment decreased by about 33%, and achieved good results. The numerical simulation analysis provides a strong basis for rational selection of the parameters of the VSR.
Effect of DC Casting Processes on Microstructure of AlCu4.5Mn0.8 Alloy
Authors: Zhou Li , Luo Gen Xiang
Published: March 2013

The semi-solid billets of AlCu4.5Mn0.8 alloy were cast respectively by low frequency electromagnetic, low-superheated, and conventional direct chill casting. The effect of casting processes on microstructures was investigated. The results show that due to the effect of the low frequency electromagnetic field, the coarse dentritic microstructure is gradually broken up and turned into the homogeneous, fine rosette-shaped non-dentritic microstructures with the increase of electromagnetic frequency from 10 Hz to 30 Hz. When electromagnetic frequency is 30 Hz, the homogeneous, fine non-dentritic microstructure what is suitable for semi-solid reheating and thixo-forming could be obtained successfully.
Numerical Simulation on Mold Electromagnetic Eccentric Stirring and Central Segregation of Round Bloom
Authors: Zhang Zhi Hong , Cheng Guo Guang
Published: March 2013

The paper describes multi-section round bloom casting using external MEMS, equipped with max section D600mm and min D280mm mold, the center line of D280mm mold not coincident with the axis of stirrer coils. it is exist eccentric electromagnetic stirring of mold which section less than max D600mm, a mathematical model of MEMS has been established, the index of central segregation of D280mm macrostructure had decreased less than 1.12 by optimized parameters of electromagnetic stirring and SEN immerse depth, in the end, the quality of round bloom had improved.
Preparation of Nanoparticles of Calcium Oxalate Dihydrate
Authors: Liang Wei Bo , Zhu Wen Yu , Wang Fen Xing , Ouyang Jian Ming
Published: March 2013

Calcium oxalate dihydrate (COD) nanoparticles with an average size of about 200 nm was prepared by complex precipitation method using potassium oxalate (K2Oxa) and CaCl2 as raw materials, NTA as complexing agent. The effects of initial reactant concentrations, pH in reaction system and dispersion media on morphology and size of the nanoparticles were investigated. The samples were characterized by X-ray diffraction (XRD), Fourier transform infrared resonance (FTIR), zetasizer Nano-ZS and transmission electron microscopy (TEM). The results indicated that the prepared sample was COD and its morphology was nearly all elliptical.
Thermodynamic Studies on Selective Oxidation of Nb, P and C in Dephosphorization of Low Niobium Hot Metal
Authors: Jin Yong Li , Zhao Zeng Wu , Zhang Jie Yu
Published: March 2013

The main problem with the efficient utilization of Nb resource in the Boyan Obo Ore lies in the selective oxidation of [Nb], [P] and [C]. In this work, thermodynamic studies have been conducted to determine the conditions of selective oxidation of [Nb], [P] and [C] in low niobium hot metal in the process of oxidizing dephosphorization. The thermodynamic condition for dephosphorization was determined as: The condition for retaining Nb from oxidation is: The oxygen activity for oxidation of Nb, C and P is relevant to the initial [C] content in hot metal. The equilibrium oxygen activity of Nb-O reaction increases with an increase of the [C] content, whereas the equilibrium oxygen activity of C-O and P-O reactions varies oppositely with the [C] content. The reduction ofresults in a decrease of the [C] content required for removing P and retaining Nb, as well as makes the process of dephosphorization more feasible. The increase of temperature decreases the [C] content of selective oxidation of Nb and P, but is unfavorable to dephosphorization.
Experimental Study on Carbothermic Reduction of Magnesia with Different Carbon Materials
Authors: Jiang Yun , Ma Hong Wen , Liu Yu Qin
Published: March 2013

The structure and composition of carbon materials affect obviously the result of carbothermic reduction of magnesia. Coke, charcoal and graphite were used in reduction experiments under the same conditions. The reactivity ratio of magnesia and XRD pattern of residues were analyzed and compared. The reactivity ratio of magnesia by coke was similar to the one by charcoal. The amorphous carbon in coke graphitized partly in reduction experiments of 1673K. The results show that the effective composition in coke is the amorphous carbon. It also suggests that the temperature of reaction should be control less than 1700K to avoid the amorphous carbon’s graphitization.
Performance Study of Composite Clay Instead of a Single Plastic Clay
Authors: Zhang Li Fang , Xiao Shu Juan , Chen Shuang , Chen Xing Gang , Dong Cui Zhi , Zhang Yu Bing
Published: March 2013

Zimujie is the common clay which has a very important position in ceramic production. It is facing with the depletion as the non-renewable resources in recent years.It is necessary to study a substitute to solve this problem . Research shows that : When the ratio of Changbai Mountain kaolin clay, Longyan clay, Suzhou clay and the northeast black mud is respectively 65.22wt%, 8.70wt%, 4.35wt%, 21.73wt% to formate the composite clay with 0.4wt% sodium carbonate addition agent, performance of the composite clay is very similar to zimujie.Therefore, it can be applied in the ceramic casting as the substitute of the single Zimujie clay.
Predicting the Mechanical Properties of Electric Porcelain Using ANN and MLR
Authors: Qiao Li , Chen Lei , Li Chun
Published: March 2013

Electric porcelain has a long history of being used as insulators and bushings in Power T&D. Its microstructure and composition has a large influence on the mechanical performance. In this paper, two different methods, including Artificial Neural Network (ANN) and Multi-Linear Regression (MLR), were employed for predicting mechanical properties of electric porcelain including elastic modulus, bending strength and fracture toughness. Most predicted values by ANN are in accordance with the actual values. MLR gives the best accurate results within the low average error level of ~1%. According to the statistical analysis, two methods are reliable and their predicted results are effective. Formulae obtained from MLR are recommended to be used for predicting the mechanical properties of electric porcelain as experienced formulae.
Research on Polymerization of PMN-PZT Piezoelectric Ceramic by Gelcasting Using NMAM System
Authors: Zhou Ping , Du Jing Hong
Published: March 2013

The industrialization of gelcasting technique has been prevented because acryamide is a neurotoxin monomer. In this paper, a low-toxicity gel system based on the polymerization of low-toxicity N-hydroxymothl acrylamide was used for the gelcasting PMN-PZT piezoelectric ceramic. The effects of monomer concentration, the dosage of initiator and catalyst, pH value on polymerization were studied. The results showed that the condition suitable for gelcasting PMN-PZT piezoelectric ceramics could be obtained while monomer concentration was 10wt%～15wt%, the dosages of initiator and catalyst were respectively 0.4 vol%～0.5vol% and 0.4vol%, pH value of slurry was about 10. The highest bending strength of PMN-PZT green body prepared at the aboved conditions can reach 19.5Mpa
Structural Stability and Electronic Properties of Fe-Doped B13C2: First-Principles Investigation
Authors: Qin Yi Wei , Lu Sen Kai
Published: March 2013

Structure stability and electronic properties of Fe-doped boron carbides (B13C2) were studied using the first principle calculations based on plane wave pseudo-potential theory. The calculated results showed that the Fe-doped boron carbide representative stable structural is Fe substituting C atom on the end of chain C-B-C. The band structure and density of states (DOS) indicated that the coexistence of [C-B-Fe] ε+-[B11C] ε- structural unit made electrical conductivity increased. As the covalent bond of Fe-B was weaker than those of B-B and B-C, the thermal conductivity decreased for Fe-doped B13C2, thermoelectric property of Fe-doped boron carbides has been improved.
Shape-Controlled Synthesis and Pattern Recognition of Dendritic Co3O4 Superstructures
Authors: Wu Mi Lin , Zhang Liang Miao , Gu Tian Hong , Qian Na , Ma Wen Jing , Lu Wen Cong
Published: March 2013

In this paper, the optimal projection recognition (OPR) developed in our lab has been used to find the regularities of forming dendritic Co3O4 superstructures. The criteria for predicting dendritic Co3O4 superstructures can be obtained by using OPR method among different kinds of pattern recognition diagrams. The new samples predicted to be dendritic Co3O4 superstructures were designed by using the inverse projection based on the OPR method. The predicted results agreed well with our experiments. Therefore, the work presented is very useful not only inthe shape-controlled synthesis of dendritic Co3O4 superstructures but also in materials design of other nanomaterials.
Rheological Properties and Crystallization Behavior of Poly(trimethylene Terephthalate) Blends with PBPCS
Authors: Wang Kun Yan , Cao Feng
Published: March 2013

Several blends of poly (trimethylene terephthalate) and the classical mesogen jacketed liquid crystal polymer poly{2,5-bis[(4-butoxyphenyl)oxycarbonyl]-styrenes}(PBPCS) have been prepared with different compositions. The rheological and crystallization properties of the prepared blends have been investigated. The effect of the PBPCS amount on the complex viscosity was quit prominent at low frequency, and decreased with increasing frequency. Differential scanning colorimetry(DSC) experiments showed that adding small content of PBPCS (0.5wt%), the melting point of was slightly higher than that of pure PTT and The crystallinity of PTT incresased.
Study on the Preparation and Properties of the Phosphorus-Containing Flame Retardant PET Copolymer
Authors: Feng Xin Xing , Liu Mei Jun , Zhang Jian Chun
Published: March 2013

The phosphorus-containing flame retardant PET was synthesized by adding different content CEPPA. The study found that the flame retardant and char formation abilities of PET increased with CEPPA content increasing, but the melting point, glass transition temperature and melt crystallization temperature decrease, and the anti-drip properties got worse and then better. It is attributed to the introduced C-P bond energy of the main chain was much smaller than the C-C bond energy.
Branched and Responsive Antimicrobial Polymers Based on Modified PVA for Functionalizing of Cellulose Fibres
Authors: Pan Yuan Feng , Xiao Hui Ning , Beh Catherine
Published: March 2013

In this work polyvinyl alcohol (PVA) was modified via grafting or coupling with the guanidine-based antimicrobial polymer using epichlorohydrin as a crosslinking agent. The resulting polymer was tested for its charge density and inhibition against E.coli. The modified PVA adsorbed onto cellulose fibres via electrostatic association; thus resulting in the hand-sheets (or paper) with improved antimicrobial activity. As a further extension of this work, the temperature-responsive antimicrobial polymers were prepared based on acetalyzed PVA (APVA) grafted with guanidine-based polymer chains. In conjunction with anionic APVA copolymer (APVA copolymerized with sodium acrylate), the cationic and responsive APVA formed a unique antimicrobial polymer system via layer by layer (LbL) assembly, which could adsorb on fibre surfaces and be incorporated into cellulose fibre networks, leading to the functionalizing of cellulose fibres. The lower critical solution temperature (LCST) of APVA copolymer could be tailored by controlling the degrees of acetalysis (DA) and co-monomer ratios. AFM images obtained to reveal the roughness of the surfaces; while the antimicrobial test proved that cellulose fiber assembled with APVA-based multilayers exhibited excellent antimicrobial activity against E.coli.
Comparison of Different Extraction Methods for Antioxidant Property of Flavonoids from Pomelo Peel
Authors: Ru Qiao Mei , Cai Ru Fan , He Jin Zhe
Published: March 2013

Antioxidant activity of the flavonoids from pomelo (Citrus grandis (L.) Osbeck) peel obtained by conventional soxhlet extraction (CSE), microwave-assisted extraction (MAE) and supercritical carbon dioxide (SC-CO2) extraction were investigated. For measuring antioxidant activities, different methods have been used corresponding to different levels of antioxidant action. The results indicated that the extraction yields of flavonoids by MAE and SC-CO2 extraction were higher than that by CSE method, whereas flavoniods by SC-CO2 extraction exhibited the strongest antioxidant activities. Our results indicated that SC-CO2 extraction method could effectively reserve the antioxidant ability of pomelo peel flavonoids.
Synthesis and Properties of Biodegradable Liquid Crystalline Poly(ester-Urethane)s Based on Poly(L-Lactic Acid)
Authors: Guo Ya Tong , Zheng Zhu , Hou Zhen Qi , Du Jie
Published: March 2013

A series of biodegradable segmented liquid crystalline poly(ester-urethane)s were prepared by solution polymerization of poly(L-lactic acid) (PLLA), mesogenic diol prepolymer poly(butylene terephthaloyldioxy dibenzoates) (MD), and hexamethylene diisocyanate (HDI). The MD content was varied from 0 to 40 mol% so that the effects of the mesogen content on the thermal and physical properties, and hydrolytic degradation were examined respectively. It was found that introducing mesogens units could increase the thermal stability and the elastic properties, while reduced the phase transition temperatures and the hydrolytic degradation rate.
The Potential Realization of Solar-Blind Ultraviolet Detecting Using ZnO-Based Alloy Thin Film
Authors: Deng Xue Ran , Deng Hong
Published: March 2013

A simple solar-blind ultraviolet (UV) detector was fabricated by using Al0.3Zn0.7O alloy thin films as photocathode and ZnO:Al (AZO) thin film as transparent electrode. Transmission spectra of Al0.3Zn0.7O alloy thin film was characterized through spectrometer and result showed significant enlargement of its optical band gap value. This alloy film only absorbed illumination whose wavelength is below 280nm, and the UV on/off characteristics of this detector presented very clearly. Scanning electron microscope (SEM) image revealed fine structure of both layers and the interface of these two layers performed clear and uniform.
Combustion Synthesis of CaMoO4:Eu3+, Li+ Red Phosphors Using Urea-Thiourea Mixture Fuels
Authors: Wang Xia , Feng Yu Zhi , Peng Gui Hua , Liang Zhen Hua , Han Xiao Bao
Published: March 2013

The CaMoO4:Eu3+, Li+ red phosphors were synthesized by combustion synthesis with urea or urea-thiourea as fuels, and their crystalline phase, morphology and luminescent properties were investigated. The XRD results demonstrated that all the diffraction peaks of the products can be well indexed to the pure tetragonal phase of CaMoO4. The SEM photographs showed that the particles of sample using urea as fuel are agglomeration, while the particles of sample using urea-thiourea mixture fuels are non-agglomeration. The powder can be effectively excited by ultraviolet with wavelength of 395 nm, and exhibits a strong red emission with maximum wavelength at 615 nm. The luminescent intensity of the phosphor with mixture fuels had 2.2 times stronger than that of the phosphor with single fuel, and its chromaticity coordinates (0.65, 0.35) was closer to NTSC standard values (0.67, 0.33).
Electrical Property of Carbon Nanotubes/Epoxy Resin/Polyetherimide Composites with Inverted-Phase Structure
Authors: Xi Dong Yong , Ma Chuan Guo , Liu Ming , Shi Rui
Published: March 2013

Carbon nanotubes (CNTs) selective dispersion and electrical properties of one kind of thermoplastic/thermosetting polymer composite consisting of polyetherimide (PEI) and epoxy resin (EP) were investigated. The results showed that, in the CNTs/EP/PEI composite, under control of thermodynamics, CNTs are preferably dispersed in PEI-rich phase, and an inverted phase structure is obtained with continuous PEI-rich phase and separated EP phase as globular shapes. And this microstructure helps to achieve a very low percolation threshold of 0.3wt% CNTs in the composite. The composites at CNTs contents over the percolation threshold, have a high dielectric constant of around 100, which first decreases slightly and the drop rapidly into a platform with increasing frequency from beginning.
Growth of ZnO Films on Si(111) by Metalorganic Chemical Vapor Deposition with AlN and Low-Temperature ZnO Double Buffers
Authors: Zheng Chang Da , Wang Li , Fang Wen Qing , Jiang Feng Yi
Published: March 2013

To enhance the quality of ZnO films on Si(111) substrate, single layers of low-temperature ZnO (LT-ZnO) and AlN, as well as a combination of AlN and LT-ZnO layer, were used as intermediate layers by atmospheric pressure metalorganic chemical vapor deposition system. Only polycrystalline ZnO film was formed when a LT-ZnO single buffer was used. Crystal quality was enhanced when LT-ZnO was replaced by 20 nm AlN as the single buffer. The full width at half maximum (FWHM) of ZnO(0002) x-ray diffraction ω-rocking curve was 642 arcsec. Cracks began to appear on the film surface as crystallinity was enhanced. A ZnO mosaic single-crystal film with a mirror-like surface was successfully fabricated when a combined AlN and LT-ZnO served as buffer, and its FWHM of ZnO(0002) ω-rocking curve peak was only 460 arcsec. The film surface was smoother but cracks were still evident on the film. Contrary to the three-dimensional growth mode of samples with a single buffer, a quasi-two-dimensional growth mode was realized for the double-buffered high-temperature ZnO layer. Calculated film thickness was 2.14 μm, and the growth rate reached 4.3 μm/h based on the laser in situ laser reflectance trace.
Measurement Error of the Coercivity Hcj of NdFeB Permanent Magnet Caused by Air Gap
Authors: Xu Wen Huan , Sun Ai Zhi , Wu Shen , Yang Jun , Zou Chao , Dong Juan
Published: March 2013

Regular rare earth permanent magnet measurement systems are only able to measure standard samples with a fixed size. But NdFeB materials are usually processed into various kinds of shapes. Bonding magnets are even often formed together with the shaft or other parts. So there will be a distinct error in conventional measurement. The magnetic field intensity distribution between two poles of the system was analyzed. Because of the existence of air gap between the magnet and the poles of the measurement system, the measurement magnetic circuit is open in this experiment. By changing the height of the magnet and air gap, the measurement error of the intrinsic coercivity Hcj of NdFeB magnets is researched under this condition.
Preparation and Research on Luminescent Properties of Eu-Doped TiO2-ZnO Composite Powders
Authors: Jiao Bao Xiang , Li Meng Ting , Zhang Xia , Wang Xu
Published: March 2013

The Eu-doped TiO2 nanocrystals with different content of Eu3+ and the Eu-doped TiO2-ZnO composite powders with different content of ZnO were prepared by sol-gel method. The X-ray diffraction (XRD) spectra and photoluminescence(PL) spectra indicated that all of the Eu-doped TiO2 have anatase structure. It indicated that the incorporation of Eu3+ can inhibit the transformation of TiO2 from anatase to rutile phase. With the increase of the content of Eu3+, the luminous intensity first increased and then decreased, and luminescent properties were best when the content of Eu3+ is 1.1%. Considering the Eu-doped TiO2-ZnO composite powders, with the increasing of the proportion of ZnO, a Zn2TiO4 phase has been gradually generated. When the content of ZnO up to 40%, the luminescent properties are the best.
Novel Preparation Method and Luminescent Properties of Eu3+ Doped CdWO4 Nanorod
Authors: Lei Fang , Chen Hao Hong , Shi Ying , Xie Jian Jun , Feng He
Published: March 2013

Eu3+ doped CdWO4 nanorods, with nearly uniform nanoscale was synthesized via a novel simple hydrothermal method easy for commercial run at 160 °C, of which the average dimensions are about 250, 50 and 20 nm in length, width and height respectively from the result of transmission electron microscopy (TEM). Powder X-ray diffraction (PXRD) pattern shows the product is pure wolframite structure. Different from undoped products showed brilliant blue-green irradiation and block crystals with multi-emission bands in red light range, the Eu doped nanorods give preferred strong 5D0→7F2 transition and are excellent red phosphor with high color purity supported by the photoluminescent (PL) measurements and ultraviolet visible diffuse reflectance spectroscopy (UV-Vis DRS). This suggests that a combination of the Eu3+ doped and undoped products are potential to realize the white lighting LED with blue, green and red components.
Flammability and Mechanical Properties of Intumescent Flame Retarded PP/EVA Composites
Authors: Wang Zheng Zhou , Xu Shao Hong
Published: March 2013

Flammability of polypropylene/vinyl acetate copolymer (PP/EVA) composites containing melamine phosphate (MP) and pentaerythritol (PER) was studied by limiting oxygen index (LOI), and UL 94. It is found that the LOI values decrease with the increase of EVA content in the PP/EVA composites. The thermal decomposition were investigated by thermogravimetric analysis. Moreover, the mechanical properties of the PP/EVA composites were studied. Compared with the flame retarded PP/EVA composites, the incorporation of a small amount of the peroxide (DCP) into the flame retarded composites leads to an increase in both tensile properties and flame retardancy.
An Investigation on Properties of Sn-SBA-16 Synthesized without Mineral Acid Added
Authors: Wu Jia Feng , Zhao Yu Mei , Liang Peng
Published: March 2013

A series of mesoporous materials Sn-SBA-16 was prepared by one-step hydrothermal synthesis with F127, TEOS and SnCl4•5H2O as template, silica source and tin source, respectively, without mineral acid added. The samples were characterized by XRD, N2 sorption, TEM and UV–Vis. The acidity property of acidic sites in the surface of the samples was investigated by pyridine-absorbed FT-IR. The results indicate that the materials exhibit high surface area and uniform pore distribution. The samples contain both Lewis and Brönsted acid sites, moreover, the total concentration of both Lewis and Brönsted acid sites increases with the decrease of the ratio of Si to Sn. And Lewis acid site plays the dominate role.
Development Toxicity and Degradation of Diethyl Phthalate
Authors: Hui Xiu Juan , Li Shuang Shuang , Liu Jian Li , Liu Bing , Cao Xiang Yu , Yang Wei
Published: March 2013

Diethyl phthalate (DEP,CAS Registry no.84-66-2), a kind of Phthalate esters (PAEs), which was used in many industries as an important industrial material, such as plastic, painting, rubber pesticide, cosmetic, etc. In recent years, DEP has caused environmental problems all over the world for widely use. This article discussed the development toxicity of DEP in microbial and plant, rats and humans and the progress of the technologies for degradation of DEP. We proposed that evaluation of the development toxicity and degradation of DEP would be important for risk assessment in humans and the environment removal.
Phosphotungstic Acid, Silicotungstic Acid and Silicon Tungsten-Cobalt Heteropoly Acid with Bovine Serum Albumin Interaction
Authors: Shen Wei Yang , Song Min Xin , Chen Jian Qiu , Guo Rui Xin
Published: March 2013

The interactions of bovine serum albumin (BSA) with phosphotungstic heteropoly acid (PW), silicon tungsten heteropoly acid (SiW) and silicon tungsten-cobalt acid (SiWCo) were studied by fluorescence spectroscopy and UV absorption spectroscopy at Tris buffer solution (pH = 7.40). It was found that the fluorescence quenching of PW, SiW and SiWCo with BSA was static and the binding constant, binding site and the thermodynamic parameters were calculated at 298 and 310K. In addition, the conformations of BSA impacted by PW, SiW and SiWCo were researched using synchronous fluorescence. The results showed that PW, SiW and SiWCo all could interact with BSA but they had not changed the conformation of BSA.
The Synthesis and Characterization of Zinc Borate Zn2B6O11·7H2O
Authors: Liu Xin , Bian Shao Ju , Gao Dan Dan , Meng Qing Fen , Wei Ming , Li Wu
Published: March 2013

Zinc borate Zn2B6O11•7H2O was prepared at room temperature using Na2B4O7•10H2O, ZnSO4•7H2O and H3BO3 as raw materials. The synthesized product was characterized by XRD, SEM, TG-DSC and FT-IR. SEM results showed that the synthesized zinc borate had uniform morphology with a length up to a few microns. The experiment result indicates that additional H3BO3 in starting materials was beneficial to the uniform morphology of Zn2B6O11•7H2O.
Synthesis of (Ba,Ti)-Doped Apatite-Type Lanthanum Silicate Nano-Sized Powders via Microwave-Assisted Sol-Gel Auto-Combustion Route
Authors: Wu Ran , Ye Jia Mei , Li Qi Zhao , Wang Sheng Yun , Chen Xiu Lei , Yang Jian Ming , Tan Gang , Liu Jun Liang , Zhang Ming
Published: March 2013

In this paper, (Ba,Ti)-doped lanthanum silicate nano-sized powders have been synthesized via microwave assisted sol-gel auto-combustion route by using TEOS and lanthanum nitrate as the starting materials, citric acid and glycol as chelators. Both the phase compositions and morphologies of the obtained powders have been characterized. The results indicated that: the synthesized nano powders were characterized as fluffy aggregates with the particle size ranging from 50 to 100nm. As the doping contents of Ba increased, the crystalline sizes decreased and the aggregation were deteriorated, while the particle size decreased from 120nm to 80nm and the aggregation between particles were halted as the doping contents of Ti increased.
Surface Passivation of Silicon Wafers by Iodine-Ethanol (I-E) for Minority Carrier Lifetime Measurements
Authors: Chen Jing Wei , Zhao Lei , Diao Hong Wei , Yan Bao Jun , Zhou Su , Tang Ye Hua , Wang Wen Jing
Published: March 2013

The effective minority carrier lifetime (τeff) depends upon the quality of surface passivation, which by means of the microwave photoconductance decays (μPCD) method. The effective minority carrier lifetime (τeff) cannot reveal the real bulk lifetime of minority carriers (τb) . We have applied iodine-ethanol (I-E) treatment to silicon surface at different molar concentrations and shown that the effective concentrations ranges was 0.08mol/L~0.16 mol/L, the maximum The effective minority carrier lifetime (τeff) of n-type monocrystalline and p-type monocrystalline was 973.71μs and 362.6μs, respectively. We also accurately evaluate the bulk lifetime of minority carriers by measured with different thickness of silicon substrate.
Effect of Phosphorus Contents on Texture and Grain Boundary Character for the Annealing High Strength Ti-IF Steels
Authors: Song Xin Li , Peng Kun , Zhang P.P. , Wu J.Y. , Zhou J. , Jia Juan , Fan L.X.
Published: March 2013

The effect of phosphorus contents on texture and grain boundaries character for the high strength Ti-IF annealed for 120sec at 810oC are researched by electron backscatter diffraction technique（EBSD）. The recrystallization texture is approximated by the γ-fiber texture whose components are {111} and {111} orientation texture. The highest volume fraction of //ND texture is almost 80% for the sample containing 0.056%P. A large amount of coincidence site lattice(CSL) grain boundaries ∑3，∑5, ∑7，∑9，∑11 and ∑13b are obtained.
Study on Metal Thermal Reduction of Caustic Calcined Dolomite Based Compound Desulfurizer
Authors: Wang Shi Jun , Fu Rui , Zhang Xue Sen , Li Jie , Zhou Chang Cheng , Pan Jun
Published: March 2013

Caustic calcined dolomite based compound desulfurizer by the aluminum thermal reduction was taken as study object. Effect of fluxing agent, reaction time and experimental temperature on the weightlessness of compound desulfurizer was studied. The result showed that the weightlessness of compound desulfurizer decreases slightly with the increase of fluxing agent CaF2 content. When the content of SiO2 changes from 12% to 20%, the weightlessness of compound desulfurizer which is basically about 27.5% changes a little. With the increase of experimental temperature and reaction time, the weightlessness of compound desulfurizer is gradually increased. When the reaction time and temperature is respectively 20min and 1300°C, the weightlessness of compound desulfurizer is 31.80%.