bluuebunny/crossref_metadata_2025 huggingface dataset:
Processing Parameters Optimization on Control of Residual Stresses and Distortion during High-Speed Milling of Thin-Walled Workpiece
Authors: Jiang Xiao Hui , Li Bei Zhi , Zuo Xiao Yan , Yang Jian Guo
Published: December 2012

In the aerospace and auto industries, the residual tensile stresses will cause the structures broke and damaged. Hence, different methods were considered to optimize the machining processes. In this article, a residual stresses calculation model using AdvantEdge 2D turning was integrated with 2D milling physical model in order to analyze high-speed milling thin-walled workpiece. Through optimizing the processing parameters (improving the cutting speed and decreasing the cutting depth) during high-speed milling, not only we can get a high removal rate and receive a distribution of equably surface residual stresses, but also a slowing down trend of in-depth residual stress can be obtained. In addition, we evaluate this method using a typical part at the sensitive area, and the machining quality can be improved obviously.
Balance Melting Point and Compatibility of Polypropylene/Syndiotactic1,2-polybutadiene Blends by Using DSC
Authors: He Xiao Feng , Zhang Hua , Ge Tie Jun , Zhang Xue Quan , Zhang Chun Yu
Published: December 2012

The balance melting point and compatibility of Polypropylene/Syndiotactic1,2 polybutadiene (PP/s-PB) blends and neat PP were studied by using DSC, the results showed that the presence of s-PB in PP would have a strong impact on balance melting point of PP. The presence of s-PB in PP could effectively decrease balance melting point of PP. Balanced melting point depression proves that there are strong interactions between two macromolecular chains in compatible part of blend. According to Nishi-Wang theory, PP and s-PB are incompatible in thermodynamics, but compatible in dynamics. Namely, PP/s-PB are partial compatible. The structure is heterogeneous in microscopy, but homogeneous in macroscopic, this also proves that there are strong interactions between two macromolecular chains in blend. The strong interactions is a kind of useful toughness effect on PP.
Crystallization Behavior of Polypropylene/Syndiotactic1,2-Polybutadiene Blends
Authors: He Xiao Feng , Wang Shuai , Ge Tie Jun , Zhang Xue Quan , Zhang Chun Yu
Published: December 2012

The melting and crystallization behaviors of Polypropylene/Syndiotactic1,2-polybutadiene (PP/s-PB) blends and neat PP were studied by using DSC, the results showed that the presence of s-PB in PP would have a strong impact on the crystallization capacity of PP. The presence of s-PB in PP could increase the crystallization temperature(Tc) of PP, and the s-PB could obviously lower supercooling temperature(Tm-Tc) of PP, but the s-PB in PP have a Slightly influence on the melting temperature(Tm) of PP. The proposed reason for those are that the crosslinking s-PB in high temperature is a nucleator for PP’s crystallization and increases PP’s crystalline rate. However, the s-PB lowers PP’s crystallinity. At the same time, the presence of PP in blends lowers s-PB’s crystallinity, but the PP in blends have a Slightly influence on the melting temperature(Tm) and crystallization temperature(Tc) of s-PB.
Surface-Modified Zeolite-Filled Poly(piperazine-amide)/Polysulfone Composite Membrane for Potassium Extraction
Authors: Hou Jin , Yuan Jun Sheng , Shang Ru
Published: December 2012

Polysulfone (PS) hollow fiber microporous membrane was used as substrate, the micropores of which were filled with surface-modified zeolites suspension on the outer surface by vacuum method, and then zeolite-filled poly(piperazine-amide)/PS hollow fiber composite membrane was synthesized on the substrate by interfacial polymerization reaction with piperazine (PIP) aqueous solution and trimesoyl chloride (TMC) n-hexane solution. The substrate membrane and synthetic composite membrane were characterized by scanning electron microscopy (SEM). A thin poly(piperazine-amide) active skin layer was synthesized on the substrate and the surface-modified zeolite particles were successfully embedded in the surface micropores of the substrate. The separation factors of the sample to K+ are 4.25, 60.46 and 93.61 in the mixed K+-Na+, K+-Ca2+ and K+-Mg2+ solutions respectively, which indicates that the sample has preference selectivity to K+ and can be used as a potential ion-exchange membrane for potassium continuous extraction from seawater.
Influence of Time on Thermo Sensitivity of Copper/Paraffin Thermo Sensitive Composite and Development of Testing Device
Authors: Lou Bai Yang , Zhou Yan , Dong Zhao Hui , Xu Bin
Published: December 2012

Nano copper /paraffin thermo sensitive composite was prepared by high energy milling and pressed into a glass cylindrical tube by using thermoforming process. Thermo sensitivity of the thermo sensitive composite was tested by thermo sensitivity tester which is developed by us. The composite particles with good cladding effects, prepared by high energy milling, arrange close together. Copper particles have no damage on the structures of paraffin. The thermal conductivity of thermo sensitive composite is enhanced with the increase of mass ratio of copper powder.
Effects of Fe-Doping on the Properties of CuAlO2
Authors: Chen Chen , Cao Jia Jia , Wang Yu , Wang Yi Ding
Published: December 2012

We added different amount of Fe (NO3)3 to the solution made of aluminum nitrate, copper nitrate and isopropanol to form gel. CuAl1-xFexO2 (x = 0, 0.01, 0.03, 0.05, 0.07, 0.09) powders and films were prepared in our experiments. The films were prepared on the quartz substrates. The powders and films were annealing at 1050 °C for 5 hours in the air. The powders were detected by X-ray diffraction to represent the structure of CuAl1-xFexO2. The square resistance of the films was determined by RTS-8 four-probe. The lowest square resistance is of CuAl0.95Fe0.05O2 film 3.3 KΩ/□ .Ultraviolet spectrophotometer (UV-3600, 230VCE) was used to measure the transmittance of the films. Fe-doping has a positive impact on the conductivity but negative impact on the transmittance.
Galvanic Corrosion between Depleted Uranium and 40Cr Steel
Authors: Pu Zhen , Wang Qing Fu , Shuai Mao Bin , Lang Ding Mu
Published: December 2012

Individual corrosion and galvanic corrosion behaviors of depleted uranium (DU) and 40Cr steel were investigated by electrochemical analyzing technologies in 3.5w.t%NaCl solution, including open circuit potential(OCP) test, linear polarization(LP) test, potentiodynamic polarizaition(PD) test, galvanic corrosion potential and corrosion current density test. The results reveal that the OCP of DU and 40Cr steel are around -790mV and -660mV, respectively. 40Cr has a higher linear polarization resistance than DU in galvanic corrosion. The dynamic processes of galvanic corrosion goes through an conversion in the whole test period. DU acts as anode with an accelerated corrosion rate, while the 40Cr steel behaves as cathode during the process of galvanic corrosion for DU/40Cr couple. The galvanic potential and current density of the DU/40Cr couple are -780mV and 17.5μA/cm-2, respectively.
Evolution of Defect Photoluminescence in Annealed N-Rich a-SiNx:H Films
Authors: Huang Rui , Song Jie , Guo Yan Qing , Song Chao , Wang Xiang
Published: December 2012

The N-rich a-SiNx:H films were deposited on Si substrates by very high frequency plasma enhanced chemical vapor deposition technique at a low temperature of 250 °C. Strong blue photoluminescence (PL), which originates from nitrogen dangling bond, can be observed in the as-deposited samples. The dependence of defect PL on annealing temperature was systematically investigated. The PL spectra reveal that the PL peak is almost independent of the annealing temperatures while the luminescence intensity rapidly decreases with the annealing temperature increasing from 400°C to 600°C. However, higher annealing temperatures over 700 °C results in an enhancement of luminescence intensity. Based on the relationship between PL spectra and bonding configurations of the samples, the evolution of defect PL with annealing temperatures was briefly discussed.
Bioinspired Synthesis of Cross-Linking of Dopamine-Containing Block Copolymers to Form Thermosensitive Covalent Hydrogels
Authors: Huang Kui , Chen Jin San , Liu Yang
Published: December 2012

Marine mussels secrete remarkable mussel adhesive proteins (MAPs) for adherence to the substrates upon which they reside. Inspired by the intermolecular cross-linking characteristics of MAPs, we report the synthesis of thermosensitive dopamine modified Pluronic copolymer (PluF127-Dopa) with high coupling efficiency. Under certain temperature and concentration, PluF127-Dopa copolymers in aqueous solution self-assemble into micelles and are able to rapidly form a more stable hydrogels upon addition of oxidizing reagents such as NaIO4, resulting from oxidative cross-linking of dopamine. UV-vis spectroscopy was utilized to identify the reaction intermediates. The sol-gel transition curves of cross-linked PluF127-Dopa hydrogels (CL-PluF127-Dopa) were determined by a vial inversion method. The critical gelation concentration of CL-PluF127-Dopa hydrogels was significantly lower than those for PluF127-Dopa and unmodified Pluronic F127. The apparent mechanical strength of CL-PluF127-Dopa hydrogels was dramatically enhanced compared to those unmodified Pluronic copolymer hydrogels, suitable for sustained drug delivery. These new biomimetic materials are expected to have potential uses in biomedical applications.
Surface Hardening of 18CrNi3MoA-SH Steel with Heating in Electrolytic Plasma
Authors: Skakov Mazhyn , Bayatanova Lyaila , Sheffler Michael
Published: December 2012

We investigated 18CrNi3MoA-SH steel, hardened by electrolyte-plasma processing method. Scanning analysis of transient surface demonstrated that in the course of details’ electrolyte-plasma heating chemical surface modification takes place along with tempering. Unit value of micro hardness on the crosscut is estimated. Micro hardness twofold increase concerning initial condition testifies to material hardness after electrolyte-plasma processing. This method advantages are minor energy expenditure in the time of tempering high speeds, possibility of local surface processing especially of large size details with complicated shape. 18CrNi3MoA-SH steel hardening by electrolyte-plasma method is performed on semi-industrial installation constructed at D.Serikbayev EKSTU in collaboration with «TehnoAnalyt» Ltd., Ust-Kamenogorsk. The detail heating temperature is 930 - 9400С, overall time of processing is approximately 5 minutes, hardening is produced at 860 - 8700C then cooled in electrolyte flux. Electrolyte composition is 10 %-s' Na2CO3 and C3H8O3. The metallographic analysis was realized on «NEOPHOT 21» microscope. The qualitative and quantitative phase analysis of steel structure was carried out on PANanalytical" X-Ray diffractometer involving Cu-K radiation. Microhardness determination was measured on PMT-3 device with diamond cutting point; by indentation load 1 N according to State Standard 9450-76.
Synthesis and Structural Characterization of Zinc and Magnesium Doped Hydroxyapatite
Authors: Zhang Hong Quan , Zhang Ming , Fu Lu Wei , Cheng Yu Ning
Published: December 2012

Zn or Mg ions doped hydroxyapatite (HA) particles were successfully developed by introducing various concentration of Zn or Mg in the starting solution using wet chemical precipitation method and followed a hydrothermal treatment. The products were identified as HA by XRD and FTIR, and the precipitated particles had a rod-like morphology. All the products for Mg and Zn ions concentration in the preparation solution less than 40 mol% were identified as HA. Substitution of Mg and Zn in HA crystal would impair the crystallization of HA and significantly reduce the length of a, c values of HA unit cell, which clearly demonstrated that Mg or Zn ions were structurally incorporated into the apatite crystals, they were not just absorbed on the surface of crystals.
Mechanochemical Synthesis of Hydroxyapatite Bioceramics through Two Different Milling Media
Authors: Adzila Sharifah , Sopyan Iis , Farius Siti , Wahab Nurfahana , Ramesh Singh
Published: December 2012

This work presents the wet mechanochemical synthesis of hydroxyapatite (HA) powder through two different milling mediums. The effect of milling mediums on powder properties was investigated. Two types of medium: water and ethanol were chosen with 370 rpm milling speed for 15 hours time. Characterization of synthesized powders was accomplished by X-ray diffraction (XRD) analysis. The green compacts were prepared and sintered in atmosphere condition at various temperatures ranging from 900oC - 1300oC. The mechanical and physical properties were evaluated under Vickers microhardness test and density measurement. Both of synthesis mediums yielded HA phases in the synthesized powders as detected by the peaks obtained in XRD analysis. Compacts synthesized in water medium (M1) showed a maximum density, 99% sintered at 1000oC and 1300oC. However, the hardness in water medium is closely similar to the ethanol medium as a function of sintering temperature where the maximum hardness was found in compacts synthesized in ethanol medium (M2) sintered at 1300oC (5.8GPa). The microstructure observed from SEM analysis was in line with the density obtained as the surface of sintered compacts synthesized in water medium (M1) contained less pores with large grain growth.
Development of Triphasic Calcium Phosphate–Carbon Nanotubes (HA/TCP-CNT) Composite: A Preliminary Study
Authors: Gunawan  , Sopyan Iis , Nurfaezah S. , ‘Ammar M.
Published: December 2012

Triphasic calcium phosphate, composed of a more stable phase hydroxyapatite (HA) and highly soluble tricalcium phosphates (α- and β-TCP) has been synthesized through hydrothermal method. In the present work, an in-situ method to disperse 1wt% multiwall carbon nanotubes (MWCNTs) within HA/TCP powder has been used in order to develop HA/TCP-CNTs composite. XRD results confirmed the formation of HA, α-TCP and β-TCP in both as-prepared powder and composite samples. The graphite peaks appeared in the composite samples as well. FTIR analysis of sintered compacted powder showed the formation of weak bands of PO43- as the temperature was increased. The sintered compacts were mechanically tested by Vickers microhardness indentation method. HA/TCP-CNTs composite was found to have a significant of Vickers Hardness of 1.98 GPa after 1100°C sintering. The morphology analysis showed that in-situ deposition technique provides homogeneous dispersion of CNTs in the calcium phosphate matrix.
The Optimization of Lapping Process Parameters Based on Extension Theory
Authors: Jiang Fan , Xiang Jian Hua , Liang Zhong Wei , Zhang Chun Liang
Published: December 2012

This paper introduced Extension optimization theory into the parameters optimization of lapping process, the five process parameters of the lapping load pressure, the platen speed, the abrasive particle size, slurry flow, lapping fluid concentration are considered, the target extension decision models and integrated decision-making correlation function are established. According to the selection criteria, the optimum solution is obtained. The results showed that: as the lapping speed of 35rpm, the pressure of 11 MPa, the abrasive particle size of W7.95, the slurry flow rate of 228.75ml/min, the slurry concentration of 25%, the surface removal rate increased, the surface roughness decreases, flatness decreases.
Morphology Transitions in RAFT Polymerization
Authors: Huang Chuan Qun , Pan Cai Yuan
Published: December 2012

Diverse nanostructural materials including spheres, nanorods, vesicles, and large compound vesicles have been created via formation of amphiphilic ABA triblock copolymers, self-assembling and morphology transition in the reversible addition-fragmentation chain transfer (RAFT) dispersion polymerization. The polymerization of styrene (St) was performed in a selective solvent, methanol, using S,S′-bis(α,α′-dimethyl-α′′-acetic acid)-trithiocarbonate terminated poly(N,N-dimethylacrylamide) (PDMAa-TC) as macro chain transfer agent and stabilizer, and 1H NMR, and TEM were used to monitor the polymerization.
Effects of Sand Blasting on the TBCs Fabrication Quality
Authors: Zou Hui , Zhang Hua
Published: December 2012

CoCrAlY bond coat(BC) and top ceramic coating(TCC) were fabricated on the GH99 super alloy by air plasma spray(APS), before TCC fabrication, BC was treated by sand blasting with different blasting parameters (blasting pressure, blasting speed). The roughness Ra of BC surface was obtained by orthogonal experiment design. Then, cross section morphology of TCC/BC interface were investigated by scanning electron micrograph(SEM), meanwhile TCC/BC interface stresses were analyzed based upon ABAQUS software using finite element method (FEM). The results show that, the roughness of bond coat surface increase first with increasing blasting pressure and speed, then decrease finally becomes stable. Both maximum tensile stress and compressive stress appear in TCC/BC interface area which is bigger in BC layer than that in TCC layer; With the increase of amplitude of interface triangle, the TCC/BC interface stress increase first then decrease until 7μm amplitude, then there appears a decrease of the interface stress.
Effect of Particle Size and Vacuum Sintering Temperature on Phase Composition and Mechanical Properties of WC-12 wt% Co Hardmetals
Authors: Chang Shih Hsien , Lee Chung Wei , Huang Kuo Tsung , Wu Ming Wei
Published: December 2012

The experimental results indicated that the WC-12wt% Co specimens showed excellent mechanical properties and microstructure by the optimal sintering process. The G5 specimen sintered at 1400°C/1 h achieved a relative density of 98% and a hardness of HRA 88.5. Meanwhile, the TRS increased to 2400 MPa. F12 specimens that sintered at 1350°C/1 h achieved a relative density of 99% and a hardness of HRA 92.5. The TRS was also enhanced to 2170 MPa. In this study, the η phase (Co3W3C) precipitated at a high sintering temperature. The precipitations generated by liquid phase sintering gathered in some specific regions of the specimens and reacted with the WC particles. In addition, Co3W3C was a hard and brittle phase that resulted in a low TRS for the specimens; and a large amount of η phases were detrimental to the fracture toughness of the specimens.
Synthesis of Biomorphic ZnO Derived from Silk Template
Authors: Wang Tian Chi , Chang Li Jing , Jia Yang , Kong Song , Wong Ching Ping , Gao Jian Ling , Tao Jing Hai
Published: December 2012

Natural silk fibers were used as the template to synthesis biomorphic ZnO fibers. Silk fibers were first immersed into a Zn(NO3)2 solution and then sintered in air at high temperatures to produce the final ZnO fibers. Their microstructures, phases, and synthesis process were analyzed. The results show that these synthesized fibers retained the morphologies of silk faithfully. The sintering temperatures had the effect on the continuity of the biomorphic fibers. The crystallite sizes of these biomorphic ZnO are in nano scale. The fabrication process of biomorphic ceramic included the formation of ZnO and removal of their silk templates. The ZnO formed before the removal of the silk-template, so that the fibrous morphology of the silk could be retained to this ZnO. The method of using bio-template could provide a new idea for the design of oxide fiber.
The Magnetic Ordering of SiCN Films Prepared by Ion Implantation
Authors: Meng Xu Dong , Yang Fu , Liu Xiao Yu
Published: December 2012

Room-temperature ferromagnetism was observed in the SiCN films prepared by ion implantation. The result indicates that N ion implantation dosage in the film has great effect on the observed room-temperature ferromagnetism of the films. Along with the increase of ion implantation dosage, the N ions increase and the magnetism enhances. Because of the ion implantation will cause a lot of defects on the surface of SiC films, which will induce a lot of vacancies. The C atoms are replaced by the N ions doped, the concentration of the N ions decides the charges states and spin polarizations of Si vacancy defects. Local magnetic moment is induced because of the spin polarization of the Si vacancy defects, and the films show ferromagnetic properties.Charge states and spin polarizations of silicon vacancy defects can be manipulated by N atoms which induces the ferromagnetism.
Studying Grading of Non-Metallic Materials on the Spiral Screen
Authors: Yelemes Darkhan Yelemesuly , Kalieva Aziza Dauletbekovna
Published: December 2012

In the article the results of studying of the equipment up-to-date condition and grading bulk construction solids theoretical examining on different fractures especially damp materials of bed, lamellar and stylus forms were obtained. It is shown that operating now plane vibration or drum screens do not satisfy to the process of grading non-metallic materials. The article considers processes of screening bulk material on the spiral vibrating screen. The screen rational parameters, which provide product of the high quality, decreasing of consumed power and increasing of efficiency, were determined. Mathematical model of the spring spiral, a spiral vibrating screen is developed. Let’s study spring spiral in two positions - static and dynamic. In the result of making static and also dynamic models we got dependences for determining the lateral strain of spiral turns. Pre-condition for making the given model is the condition of complete spiral loading with input bulk material providing rational values of screening efficiency and effectiveness. The obtained mathemati-cal model of springing spiral, spiral vibration screen will allow to produce qualitative analysis of work of totally new innovating screen
Micro-Flow Induced Peculiar Surface Profile of Film from Dried Droplet of Water-Poly(Ethylene Oxide) Solution
Authors: Hu Yin Chun , Zhou Qiong , Dong Cui Cui , Cui Li Shan
Published: December 2012

We report a peculiar surface of poly(ethylene oxide) (PEO) film from droplet of water-PEO solution dried at heating substrate. The drying process contains two stages. The contact line is pinned initially. When substrate temperature reaches 60 °C, it starts to recede and continues to leave a film. The resulted film contains an edge-ring and middle-step surface profile. The rheological properties of PEO solution were studied. We found that capillary flow is dominant in the first drying stage and Marangoni flow appears because concentration gradient induced strong Marangoni effect and high temperature induced sharply decrease of viscous stress resulted in the contact line receding in the later drying stage. We confirm that the ringlike deposit is formed by outward capillary flow and the step in the middle is formed by Marangoni flow which carries solute to the inner, and these flows compete with the viscous force.
Preparation and Microwave Absorption Property of Nickel Spinel Ferrite
Authors: Liu Yuan , Liu Xiang Xuan , Zhang Ze Yang
Published: December 2012

NiFe2O4 ferrite was synthesized by sol-gel method. Its structural characteristics, morphology, electromagnetic and microwave absorption properties were analyzed by X-ray diffraction, scanning electron microscope and network analyzer, and analyzed the influence of the combustion temperature and citric acid. The results indicated that the particle size be enlarged with an increased combustion temperature and be diminished first, then increased with the increased of citric acid, and the best ratio of citric acid with metal ions for nCA: nFe: nNi = 4:2:1. Its microwave absorbing property is increased with the increased combustion temperature. Its complex permittivity imaginary part first decreases with temperature increases and then increases, the imaginary part of complex permeability with increasing temperature increases, indicating that the increase of calcination temperature, help to improve the sample microwave absorbing properties.
The Effect of Temperature on Performance of Powder Activated Carbon-I Membrane Biological Reactor (PAC-IMBR)
Authors: Ma Xing Guan , Ji Wen Juan , Sun Jun Ping , Xue Xiang Xin , Yang He , Fu Jin Xiang
Published: December 2012

Under the unique long-time low temperature conditions (average 8°C) of the northern winter in China, the effects of temperature on water quality and the performance of Powder activated carbon-I Membrane biological reactor (PAC-IMBR) were studied and demonstrated quantitatively by the NH4+-N value, chemical oxygen demand (CODCr) and transmembrane pressure (TMP). The results showed that the supernatant NH4+-N decrease from 1.20 mg·L-1 to 0.81 mg·L-1 with the temperature rising from 8°C to 20°C, while 30.8 mg·L-1 to 23.1 mg·L-1 for the CODCr. However, the temperature rising have no marked influence on the effluent NH4+-N and CODCr due to the filtration of membrane. TMP was measured to characterize membrane fouling and it is clear that the TMP and its increasing rate descend with the temperature rising, which demonstrates that the raising temperature is advantageous to prolong the cycle of PAC-IMRB and alleviate the membrane fouling.
The Influence of Atmosphere on Electrical Transport Properties in Bilayer Graphene FET by CVD Methods
Authors: Peng Gang , Yu Xiao Yan , Zhou Ying Qiu , Wang Guang , Wang Li , He Yan Lan
Published: December 2012

The desorption process for ambient atmosphere on electrical transport properties of bilayer graphene FET grown by CVD methods on SiO2/Si substrate was investigated in room temperature. With increasing the vacuum time of the device underwent, we found that the voltage of Dirac point decreased, the mobility of hole (electron) increased and the charged impurity density decreased. The results suggest that the atmospheric adsorbates (mainly oxygen and water molecules) are strongly influence the electrical transport properties of graphene FET.
Photoluminescence Properties of Silicon Nitride Prepared by VHF-PECVD
Authors: Song Jie , Guo Yan Qing , Song Chao , Wang Xiang
Published: December 2012

Since the visible photoluminescence (PL) in porous Si was observed by Canham, much attention has been paid to the light emission from silicon-based materials. In this work, luminescent amorphous silicon nitride films were prepared by very-high-frequency plasma enhanced chemical vapor deposition technique using ammonia, silane and hydrogen as source gases at a low temperature of 50 °C. It is found that the films exhibit strong visible light emissions with ranging from green to red region. Photoluminescence spectra show that the emission peaks as well as intensity strongly depends on the flow rates of ammonia. Combining with the analyses of Fourier transform infrared absorption spectra and the transmission spectra, it is suggested that the light emissions are originated from the radiative recombination in the band-tail states of amorphous silicon nitride.
Study of Temperature Stability of the Magnetoresistance and Transport Properties in La0.6Sr0.15Na0.10.15MnO3 with the Addition of Ag
Authors: Hu Li Chun , Zhao Hong Wei
Published: December 2012

A series of bulk polycrystalline samples of La0.6Sr0.15Na0.10.15MnO3( represents vacancy)with Ag addition were prepared by conventional Sol-gel reaction processing in air.The mol proportion between La0.6Sr0.15Na0.10.15MnO3 and Ag is 1:x (x=0.00,0.016,0.04,0.1). This article focuses on the impact of Ag doping on the parent structure, magnetic properties and magnetoresistance. We have gotten the following experimental results:X-ray diffraction patterns show that a weak Ag phase appears when ;The Curie temperature of the doped samples is higher than that of the matrix sample and it reduces as x increases. The resistivity of the doped samples is bigger than that of the parent sample in zero field and it increases as x increases.In a quite wide temperature range (207K-286K), MR maintains the value of 5.08% (0.20%) when x=0.04. So the CMR temperature stability has been improved.
Study on Novel Structure of Mn-Di(3,4,6,7-tetramethyl-1,10-phenanthroline) Dichloride: [Mn(C16H16N2)2]·Cl2
Authors: Liu Hai Xing , Guo Hua Mei , Xiao Jing Zhong , Zeng Guang , Yue Hui Juan , Tai Xi Shi
Published: December 2012

Metal complexes containing diimine ligands such as 1,10-phenanthroline and bipyridine are very important and widely used in analytical chemistry, catalysis, electrochemistry, ring-opening metathesis polymerization and biochemistry. 1,10-phenanthroline, which is the parent for important class chelating agents, has been widely used in the construction of supramolecular architectures. Lots of phenanthroline and its derivatives complex have been synthesized and reported. In the paper, a novel Mn and 3,4,6,7-tetramethyl-1,10-phenanthroline complex [Mn(C16H16N2)2] •Cl2 has been synthesized from a solution reaction and the crystal structure has been determined by means of single-crystal X-ray diffraction. [Mn(C16H16N2)2] •Cl2, Orthorhombic, Pnna. a = 8.8376(8)Å b = 18.3630(17)Å c = 18.0159(18)Å α=β=γ=90°. V= 2923.7(5)Å3. Z=4. Rgt(F) = 0.0341, wRref(F2) = 0.0958. T= 273(2) K. The novel Mn metal complex structure is explained clearly.
A New Energy Saving Roofing Insulation Board System of Polyphenylene Foam Concrete
Authors: Xia Dong Zhou
Published: December 2012

In engineering practice, the most widely used roof insulation materials are expanded perlite, expanded vermiculite, extruded polystyrene board (XPS), expanded polystyrene board (EPS), foam glass block，rigid polyurethane foam insulation layer, and so on. These products have many advantages, such as light weight, high compressive strength, good integral property, convenient construction. But there are a lot of defects at the same time, such as bad fireproof performance and durability, environmental pollution, and so on. So we need an efficient roofing insulation materials to meet the growing needs of the roofing energy saving, energy saving roofing insulation board system of polyphenylene foam concrete just meet this demand, it has the characteristics of thermal insulation, lightweight and compressive resistance, waterproof and moistureproof, fire durable, and simple structure. Through the application of this new materials in practical engineering, the energy saving roofing insulation board will provide an efficient and practical material for future roof thermal insulation and energy saving.
Numerical Analysis on Flexural Capacity of Prestressed Steel Reinforced Ultra-High Strength Concrete Beams
Authors: Meng Gang , Zhang Li Hua , Jia Jin Qing
Published: December 2012

As a new type of composite structural system, the prestressed steel reinforced ultra-high strength concrete (PSRUHC) beam was applicable to large-span structures and those structures which must bearing heavy loading. But by now there is no mature calculation method for the beam with a good accuracy. So the experiment on eight post-tensioned bonded prestressed steel reinforced ultra-high strength concrete beams had been carried out to investigate the flexural performance of PSRUHC beams. Based on the test results, the flexural capacity of PSRUHC beams were analysed by the large general-purpose finite element program ANSYS. Compared the simulation results of cracking load, ultimate load, yielding load and load-displacement curve with the test results, it is proved that the numerical method is effective for analyzing flexural capacity of prestressed steel reinforced ultra-high strength concrete beams, which provides theoretical foundation for practical application of PSRUHC beam.
Dispersion and Thermal Conductivity of Al2O3 and TiO2 Binary Nanofluids
Authors: Yang Liu , Du Kai
Published: December 2012

The dispersion stabilities and thermal conductivities of Al2O3 and TiO2 ammonia water nanofluids are investigated by the absorbency index methods and transient double-hot-wire method, respectively. The results show that the dispersion stabilities of the two kinds of binary nanofluids are greatly improved by adding surfactants or increasing the ammonia content. The effective thermal conductivity ratios of the two kind of binary nanofluids increase with the increase of the content of nano-particles. It is the same with the increase of the ammonia content. The thermal conductivity will decrease with the rising of storage time by the role of natural sedimentation. The thermal conductivity of TiO2 nanofluid is more insensitive to the storage time than Al2O3 nanofluid because of its better dispersion stability
The Thermal Conductance Estimation of Uncooled Microbolometer
Authors: Chen Chao , Jiang Ya Dong , Zhou Hong Xi
Published: December 2012

Thermal conductance of microbolometer has a directly impact on Noise Equivalent Temperature Difference (NETD) and thermal time constant which are the key indicators of uncooled IR detector. It is of great significance to calculate and evaluate thermal conductance. A calculate approach of thermal conductance for uncooled microbolometer detectors is introduced in this paper. Accurate three-dimensional modeling of microbolometer is found by using MEMS analysis software Intellisuite. Dynamic thermal analysis of this model is solved and then thermal time constant can be read from thermal time curve of the analysis mentioned above. Combined with the calculation of thermal capacitance, more precisely thermal conductance value can be reached which is more accurate than theoretical calculations result and meaningful for design and fabrication of the device.
Recent Progress on Controlled Dielectrophoretic Assembly of Carbon Nanotubes
Authors: Ding Chao , An Li Bao , Yang Xiao Xia , Liu Yan Yan
Published: December 2012

Carbon nanotubes (CNTs) have drawn extensive research interest for a variety of applications in single electron transistors, field emission displays, interconnects, sensors, energy storage, composites, and many others due to their excellent electrical, mechanical, and thermal properties. One requirement for many of these applications is the need to integrate CNTs into various devices or circuits as functional components and different manipulation methods have been developed. This paper addresses the assembly of CNTs by dielectrophoresis (DEP) and reviews recent research progress of controlled assembly of CNTs. Totally six approaches are introduced in which different techniques including impedance measurement, optical induced DEP, floating electrode DEP, self-limiting resistor, fluidic assisted deposition, and real-time gap impedance monitoring of DEP are respectively used to control the yield of the DEP process. The advantages and disadvantages of these methods are analysed. The purpose is to help automating the DEP process of CNTs and other one-dimensional nanomaterials by presenting these advanced control techniques.
The Effect of Chromium, Titanium and Aluminum on the Friction Coefficient and Wear Property in the Nitride Coatings
Authors: Han Liang , He Liang , Liu De Lian
Published: December 2012

A serious of nitride coatings including chromium, titanium and aluminum are deposited on the glass and stainless steel by Closed-Field unbalanced magnetron sputtering. The friction coefficient is measured by tribolometer and the wear traces of the coatings can be studied by the optical micrographs, those indicate that the friction coefficients of TiN、 CrN、TiAlN、CrAlN and CrTiAlN decrease sequentially as well as the anti-wear of the coatings can be enhanced. According to X-ray photoelectron spectroscopy analysis for the coatings, aluminum nitride can be indentified in the nitride coatings with Al element, which enhances the hardness and anti-wear performance of the coatings. The chrome oxide can be found in the nitride coatings with Cr element, which enhances the self-chip removal ability of the coatings and decreases the friction coefficients of the coatings; titanium oxide existing in the coatings is not good for the friction and anti-wear of the coatings. Chromium titanium aluminum nitride naturally is of higher hardness than the ternary nitride, as well as Chromium and aluminum in the coatings is in favor for the low friction coefficient and good anti-wear property.
One-Step Hydrothermal Synthesis of MoS2 Nano-Flowers with High Surface Area and Crystalline
Authors: Li Yan Juan , Li Nan , Yan Xiao , Chi Yue , Yuan Qing , Li Xiao Tian
Published: December 2012

One-step and controlled pH hydrothermal synthesis of transition metal disulfide using double molybdenum sources to synthesize MoS2 nano-flowers at low temperature was first reported. Anhydrous molybdenum pentachloride (MoCl5) and four sulfur ammonium molybdate ((NH4) 6Mo7O24•4H2O) were the molybdenum source and CS (NH2) 2 was the sulfur source. Through hydrothermal method, MoS2 was obtained at 180 °C. The pH value of system was controlled by adjusting the molar ratio of MoCl5 and (NH4) 6Mo7O24•4H2O. The products were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), surface area (BET) and transmission electron microscopy (TEM). The results show that the products were hexagonal MoS2 with a high crystalline and flower-like structure consisted of small particles. The thickness of petals is a few to tens of nanometers. By changing the molar ratio of molybdenum sources, the resultant phase from the mixed phase transited to the pure phase and the purity of synthetic MoS2 crystal increaseed.
A Novel Synthesis of CaWO4:Eu3+ Flower Like Microcrystals in Ethanol/Water Mixed System and Characterization
Authors: Chen Ye Qing , Lee Joo Hyun , Park Sung Wook , Moon Byung Kee , Choi Byung Chun , Jeong Jung Hyun , Jang Ki Wan , Lee Ho Sueb , Yi Soung Soo
Published: December 2012

In this paper, we report a successful synthesis of CaWO4:Eu3+ phosphor via an ethanol assisted hydrothermal process. X-ray diffraction (XRD) patterns, X-ray photoelectron spectroscopy (XPS) and field emission scanning electron microscope (FE-SEM) were used to investigate the growth of the products. The water and ethanol volume ratio is found to have extraordinary effect on the particle size and morphological appearance. Flower like ~ 1µm superstructures can be obtained with mixed solution of w/e of 50/50 at 120 °C hydrothermal sysnthesis for 12 h. High concentration of ethanol in aqueous solution was discovered to have a tendency in limiting the interaction between the small particles for crystallization. Temperature and time experiments were also performed to further investigate the growth mechanism of the ethanol assisted hydrothermal process. The photoluminescence properties of flower like CaWO4:Eu3+ has also been investigated.
The Effect of Density and Surface Area on Carbon Nanotube Capacitive Sensors for Dimethyl Methylphosphonate Detection
Authors: Jing Hong Jun , Jiang Ya Dong , Du Xiao Song
Published: December 2012

Capacitive sensors for dimethyl methylphosphonate (DMMP) detection were prepared on interdigitated electrodes by airbrush process. Multi-walled carbon nanotubes (MWNTs) and single-walled carbon nanotubes (SWNTs) were used as the chemically sensitive materials, respectively. Different airbrush carbon nanotube thin films were observed and compared by field-emission scanning electron microscope. It indicated that the capacitance of airbrush MWNT sensor decreased immediately when exposed to DMMP and recovered rapidly when removed DMMP in the range of 12-60 mg/m3(2.4-12 ppm). The sensitivity of airbrush MWNT sensor was about -1.39% at the concentration of 12 mg/m3(2.4 ppm). It was obvious that the capacitance sensitivity was higher when the MWNTs were more and the film was denser by airbrush. It was also found that the capacitance sensitivity of airbrush SWNT sensor was higher than the corresponding airbrush MWNT sensor.
Study on the Preparation of PSA NanoFibers Using Electro-Spinning Technology and its Characterizations
Authors: Chen Wen Jie , Xin Bin Jie , Wu Xiang Ji
Published: December 2012

Polysulfonamide (PSA) superfine fibers were prepared by the self-developed device using the electrospinning technology. The micro surface morphology of the manufactured PSA fibers was characterized by the Scanning Electron Microscope (SEM). It was found that the diameter of PSA fibers and its variance can be influenced by the electrospinning parameters. The experimental results indicate that the morphology of PSA fibers ranged from irregular (beaded) to uniform structure with an increase of solution concentration; the thickness and its variance of the PSA fibers were decreased with the increasing of applied voltage; the morphology and thickness of the PSA fibers were also affected by the tip-to-collector distance. Our investigation shows that the diameter of the PSA fibers can reach around 100nm when spun at the conditions of 28kv applied voltage, 10wt% solution concentration and 15 cm tip-target distance, with a related homogeneous network distribution.
Electrospinning of Regenerated Silk Fibroin/Polybutylene Terephthalate Blended Mats and their Surface Wettability
Authors: Cao Yun Qian , Ke Qin Fei , Jin Xiang Yu , Guo Sha Sha
Published: December 2012

In this paper, regenerated silk fibroin/polybutylene terephthalate blended mats were prepared using electrospinning method with different blending ratios. The influence of regenerated silk fibroin/polybutylene terephthalate ratio on the morphology behaviors, fiber diameter and the surface wettability of the blended mats were studied. The morphology of the electrospun fibers were characterized by SEM. The average fiber diameter and its distribution can be obtained from the SEM pictures using software Image J. The average fiber diameter was 280nm to 486nm and it changed with the blending ratio. The contact angles and penetration times were used to characterize the surface wettability of the nanofiber membranes. It was found that with the increase of regenerated silk fibroin amount, the surface contact angles and penetration times decreased, which meant that the wettability was greatly improved.
Role of Interfacial Surfactant Layers in the Thermal Conductivity of Nanofluids
Authors: Yang Liu , Du Kai , Wu Yun Long , Bao Shuai Yang
Published: December 2012

Various mechanisms and correlations have been developed for prediction of thermal conductivity of nano-suspensions. However, seldom theoretical researches on thermal conductivity of nanofluids containing surfactant are found. In this work, a thermal conductivity prediction-model of nanoﬂuid containing surfactants is proposed based on Leong et al.’s model and Langmuir adsorption theory by considering the interfacial surfactant layers. The thickness of the interfacial layer is defined by Langmuir adsorption theory. Compared with the experimental data available in the literature on thermal conductivity of nanoﬂuid containing surfactants, the calculated values on the proposed model have been verified that the proposed models show reasonably good agreement with the experimental results and give better predictions for the effective thermal conductivity of nanofluids compared to existing classical models.
Preparation and Photocatalytic Properties of Nano Ni/TiO2 Composite in Alginate
Authors: Chen Hai Feng , Yan Ting
Published: December 2012

New nano nickel-doped titanium dioxide composites had been produced by a conducting sol-gel method. The alginate gel was used as a template to prevent the conglomeration of the inorganic materials. In this experiment, nickel nitrate, tetrabutyl titanate and sodium alginate were used as main materials to prepare different amount nickel-doped TiO2 particles. The amount of Ni was studied from 0 to 9 mol.-% (where mol.-% refers to the Ni/TiO2 molar ratio), and the Ni/TiO2 composites were characterized by XRD, FT-IR, TG-DTA, and we carried out doping amount, catalyst amount and illumination time influence on photocatalytic performance of nano Ni/TiO2 composite in aqueous methyl orange. The activity of TiO2 gradually increased with the increasing of doping amount, and there was highest catalytic efficiency when Ni = 9 % mol.
Research for Extraction Method of MEMS Devices Macro-Model
Authors: Zhang Huan , Chen Chao , Wang Tao , Ma Shu Min , Zhou Hong Xi , Deng Ya Nan
Published: December 2012

The purpose of extracting Macro-model of macro sensor is to find out the mathematical model representing system characteristics of behavior efficiently and accurately. A good understanding of the whole system, collaborative simulation with circuit and optimize system design are meaningful. Whether the extraction of device level Macro- model is truly effective or not, it directly influences the simulation results of system level. Therefore, an effective extraction method of Macro-model is crucial to system simulation. Meanwhile, fast and effective extraction approach for MEMS devices Macro-model will continue to be the main future development of technology. This paper presents a fast automatic extraction technology for Macro-model. Coordinating physical level and system level is to meet the demands of system level fast modeling and simulation.
Biomimetic Polypyrrole with Hierarchical Structures and Investigation of its Bio-Sensing Properties
Authors: Zhu Shen Min , Chen Yu Hang , Tang Jie , Zhang Di
Published: December 2012

Polypyrrole (PPy) with hierarchical structures inherited from butterfly wings were prepared by using a two-step templating process. Firstly, SiO2 replica was synthesized from butterfly wings by using a sonochemical method and then the obtained SiO2 replica was used as template for the fabrication of PPy with hierarchical structures by using an in situ polymerization method. The precise structues of PPy replica down to nanometer’s level were confirmed directly by FE-SEM, TEM images. The primary response of the replicas to dopamine (DA) as a biosensor was investigated by cyclic voltammetry, and it was found that the PPy replicas showed a much higher biological activity compared with that of common PPy powders, probably due to the hierarchical structures as well as controlled porosity inherited from butterfly wings.
A Hybrid-Structured Microfluidic Chip Developed for ATP Bioluminescence Detection
Authors: Zhang Wu Ming , Li Zhen Yu , Chen Tao , Yao Jian Jiang , Lv Yang , Li Min , Li Guang
Published: December 2012

A hybrid-structured microfluidic chip integrating optical fiber sensing technology and bioluminescence chemical reaction mechanism was developed for rapid and sensitive detection of adenosine 5’-triphosphate (ATP). This microfluidic chip was fabricated with five distinct layers for the successive steps of sample-enzyme reagent mixing, bioluminescence chemical reaction and scatting light collection. The experimental results demonstrated that the provided hybrid-structure improved the sensitivity, response time, reagent consumption and other properties of chip. This improvement enables the microfluidic chip to attain a sensitive ATP detection in the range from 10-9to 10-4M with excellent linearity (R2= 0.9967), low detection error (CV < 15%), and tiny reagent consumption (< 20 μL). These achievements thus indicated that the chip developed in this study possess the advantages such as high sensitivity, quick-response and small reagent consumption.
Preparation and Investigation of Toluene-Sensing Properties of Polymer/Inorganic Composite and Multi-Layer Films
Authors: Liao Jian , Xie Guang Zhong , Jiang Ya Dong , Zhu Tao , Li Wei Zhi , Tai Hui Ling
Published: December 2012

In this paper, poly 4-vinylphenol (P4VP)/multi-wall carbon nanotubes (MWNTs) composite film, P4VP/ carbon black (CB) composite film and P4VP/MWNTs multi-layer sensitive films prepared using airbrush technology were deposited on interdigitated electrodes to detect tolunene vapor at room temperature. The surface of the composite film was observed under a scanning electron microscope (SEM). It was found that the resistance of the sensor increased after the exposure to toluene vapor and the increased magnitude of the changes had a good linearity with concentrations of toluene. Meanwhile, the P4VP/MWNTs composite film sensor also has a higher sensitivity than P4VP/CB composite film sensor. P4VP/MWNTs three-layer film sensor was fabricated as well. It was estimated that the response time and recovery time of P4VP/MWNTs three-layer films sensor were about 15 s and 20 s, respectively. The sensor responses of S=0.12% at 10mg/m3 toluene vapor for P4VP/MWNTs three-layer films. The results showed that the multi-layer films sensor exhibited a lower detection limit and better sensing properties compared with the sensors based composite film.