bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation and Characterization of PP-g -GMS -St For PP/O-MMT Composite Materials
Authors: Wang Shao Hui , Yang Shao Ming
Published: May 2011

A new compatibilizer with polypropylene as matrix, Glyceryl monostearate (GMS) and styrene(St) as functional group was prepared, and its effect on the properties of polypropylene(PP)/montmorillonite(MMT) nanocomposites was investigated. Fourier transform infrared spectroscopy results showed that the GMS and St monomers had successfully been grafted on the backbone of PP. The characterization results of X-ray diffraction(XRD) pointed out the crystallite size perpendicular to the crystal plane in PP/ compatibilizer / MMT nanocomposites was smaller than that of PP. Through detecting of transmission electron microscope(TEM), it can be found that the new compatibilizer will improve the dispersibility of MMT in PP matrix. At last, the mechanic properties of PP/MMT nanocomposite materials get determination, the mechanical strength especially impact strength had a obvious progress when O-MMT was added, and its maximal value impact strength appears in the 3% montmorillonite and 20% compatibilizer.
Manganese Silicate Catalyzed Ozonation of m-Chloronitrobenzene in Drinking Water
Authors: Liu Yue , Chen Zhong Lin , Liu Yu , Han Ying , Wang He , Shen Ji Min
Published: May 2011

Manganese silicate, a stable and efficient catalyst prepared in the laboratory has been successfully used as a catalyst combined with ozonation in the degradation of m-Chloronitrobenzene (mCNB). The catalytic ozonation removal effectiveness of mCNB was investigated under various physicochemical conditions. Both the adsorption and the single ozonation were not effective for the degradation of mCNB, but the presence of manganese silicate in ozonation process could substantially enhance the mCNB removal efficiency. The hydroxyl radical scavenger experiment confirmed that manganese silicate catalytic ozonation followed a radical - type mechanism. The increasing of the manganese silicate dosage could enhance the removal effectiveness of mCNB. The manganese silicate catalyst could be recycled easily without decreasing any ozone catalytic activity after four successive reuses. It is concluded that the manganese silicate was an efficient green catalyst for mCNB degradation in drinking water.
Engine Oil-dish Dies Design Based on CAE
Authors: Zhou Jian , Li Li Jun , Zhou Wen Xiu , Zhou Dong Cheng , Cheng Ke
Published: May 2011

For getting higher quality product and reducing cost, the article studies the CAE technology used in dies’ design, CAE will help to determine the flattened workpiece size, through workpiece igs file input, grids devided, concrete parameters set, workblank and drawing ribs created, drawing ribs load set, the workpiece produced process will be simulated, the final frame can be watched.while all are well designed, the qualified dies can be obtained.
Preparation and Characterization of Fe3O4-Pt/C Electro-Catalysts for Zinc-Air Battery Cathodes
Authors: Zhao Hong , Wang Hai Li , Liang Li Jun , Xu Hong Feng , Fu Jie
Published: May 2011

Fe3O4 modified Pt/C electro-catalyst was synthesized and studied. Fe3O4 and Fe3O4 with carbon coating (designated as Fe3O4/C) were prepared by co-precipitation method and ethyl acetate pretreatment. Fe3O4 and Fe3O4/C were sprayed onto the Pt/C cathode surface. X-ray diffraction (XRD) and Transmission Electron Microscopy (TEM) results show that Fe3O4 and Fe3O4 with carbon coating nano-particles (Fe3O4/C) are distributed evenly and c.a. 11.2 nm and 14.3 nm, respectively. TEM images show that electrode surfaces with Fe3O4 and Fe3O4/C are of little difference from that with Pt/C only; Fe3O4/C is much more evenly distributed on the electrode surface than Fe3O4 because of the adaptability of carbon coating. Cathodic curves of Rotating Disk Electrode (RDE) tests shows that the adding of Fe3O4 (7 wt %) improves oxygen reduction reaction (ORR) activity about 30 mV in both cases. The adding of Fe3O4/C (Fe3O4: 7 wt %) to the Pt/C catalysts demonstrates the highest peak current of about 13.8 mA•cm-2 in all cases. The promotion of Fe3O4 in O2 enrichment and dispersion of Pt particles are confirmed in the study. The paramagnetism of Fe3O4 and its promotion in 4-electron oxygen reduction reaction (ORR) are the possible reasons for the promotion.his template explains and demonstrates how to prepare your camera-ready paper for Trans Tech Publications. The best is to read these instructions and follow the outline of this text.
A Stable Biomimetic Superhydrophobic CuO Surface Prepared by a Facile and Inexpensive Environmental-Friendly Method
Authors: Yuan Zhi Qing , Hao Xi Hai , Shi Pu , Liu Yue Jun , Zeng Guang Sheng
Published: May 2011

A facile and inexpensive environmental-friendly method was developed to prepare a biomimetic superhydrophobic CuO surface with hierarchical micro- and nanostructures by the combination of a simple solid state reaction and a convenient dipping-coating method. The biomimetic CuO surface showed superhydrophobicity even for some corrosive liquids including salt solutions and acidic and basic solutions at a wide pH range from 2 to 13. Moreover, the superhydrophobic CuO surface showed high stability in ambient environment even exposed to ultraviolet light for 10 h.
Research on Effects of Inhibitors on Anti-Corrosion Performance of Reinforced Bar in the Concrete
Authors: Song Liu Bin , Yang Dao Wu , Xiao Zhong Liang , Zhang Feng
Published: May 2011

The corrosion behavior of reinforcing bars in concrete was studied by simulating the 4×4 wire-beam electrode array. Different inhibitors were added to reinforced concrete. By measuring the open-circuit potential of an iron wire, the impact of different inhibitors on the corrosion of rebar in the concretes was studied after immersion in NaCl solution. The result showed that best protection was achieved by adding NaNO2 and aniline as inhibitors jointly to the concrete, as this combination maintained the open-circuit potential within the passivation range at all times, so ensuring the integrity of the passive membrane. By addition of this combination of the inhibitors, the compactibility of the cement concrete structure can be increased, thereby protecting the reinforcing bar against the external corrosive media.
Transparent Polyimides and their ITO Flexible Conductive Film
Authors: Lu Yun Hua , Hu Zhi Zhi , Bian Ji Ming , Wang Yong Fei
Published: May 2011

The preparation and properties of indium tin oxide (ITO) coated transparent polyimide substrates were reported in the paper. The transparent polyimide films were prepared through thermal imidization of poly(amic acid) films. Transparent conducting ITO films were prepared on polyimide substrates by magnetron-sputtering technique at room temperature. The optical and electrical properties of the obtained films have been investigated. Polycrystalline ITO films were deposited with resistivity as low as 10-4 Ω.cm on polyimide substrates. The average transmittance exceeded 78% in the visible spectrum for 200nm thick films deposited on polyimide.
Corrosion Properties of Arc Spray Zn-25Al and Zn-50Al Coating in Marine Environment
Authors: Zhu Qing Jun , Wang Kai
Published: May 2011

Zn-25Al and Zn-50Al coatings were prepared by arc spray in mild carbon steel Q235. The corrosion behaviors of these coatings were studied by potentiodynamic polarization test in natural seawater, corrosion potentials and electrochemical impedance spectrum. The results show that the Ecorr of Zn-25Alcoating is -1.025V (SCE) and the Ecorr of Zn-50Al coating is -0.997V (SCE) at the beginning of the immersion. The Ecorr of the Zn-50Al coating is not stable as the Zn-25Al coating. Self-corrosion potential of Zn-25Al coating is lower than Zn-50Al coating. Zn-25Al can provide lower protection potential and promising current to protect the substrate from corrosion than Zn-50Al. The EIS of these two coatings reveal single capacitive loop. The anti-corrosion properties of Zn-25Al coatings are better than that of Zn-50Al coatings.
Research of Impact of Stray Current from Urban Rail Transit System on Buried Gas Pipeline
Authors: Chen Zhi Guang , Qin Chao Kui , Zhang Yang Jun , Tang Ji Xu
Published: May 2011

The principle and characteristic of Stray Current (SC) resulting from rail transit system were introduced. Measurement methods and corrosion evaluation of SC were also discussed. For an underground gas pipeline located in the neighboring area and parallel to the rail transit in Shanghai, a virtual instrument-based SC monitoring system was developed to measure pipe-to-soil potential, current within pipeline. Results obtained from Fourier transformation reveal that pipe-to-soil potential fluctuation of the tested gas pipeline is 200mV and the current is 150 mA, which is closely related to operation of subway. Serious corrosion of the buried gas pipeline might happen.
Effect of Piezoelectricity on Nonlinear Free Vibration of Moderately Thick Laminated Piezoelectric Plates
Authors: Zheng Yu Fang , Deng Li Qiong
Published: May 2011

On the basis of laminated plate theory and piezoelectric theory, the nonlinear free vibration governing equations for symmetric cross-ply moderately thick laminated piezoelectric plates are established. The Galerkin procedure furnishes an infinite system of equations for time functions which are solved by the method of harmonic balance. In the numerical results, the influences of piezoelectric effect and various location of piezoelectric layer on the nonlinear vibrating frequency of the laminated piezoelectric plates are discussed.
Solvothermal Synthesis of Nanostructured α-Ni(OH)2/ Mesoporous Carbon Composites for Supercapacitors
Authors: Yu Zhan Jun , Dai Ying , Chen Wen
Published: May 2011

Nanostructured α-Ni(OH)2/ mesoporous carbon composites were synthesized by a facile solvothermal method using sodium dodecyle sulfate as a soft template and urea as a hydrolysis-controlling agent. The obtained products were characterized by X-ray diffraction(XRD), and scanning electron microscopy(SEM). Electrochemical properties studies were carried out using cyclic voltammetry(CV) and galvanostaitc charge/discharge method. The results exhibited that the α-Ni(OH)2/ mesoporous carbon composites single electrode had high specific capacitance in KOH electrolyte. The maximum specific capacitance of the α-Ni(OH)2/ mesoporous carbon composites single electrode was up to 2191 F/g in 6 M KOH solution at a charge-discharge current density of 4 mA/cm2, when the mass percent of mesoporous carbon was 5%. It is suggested its potential application in the electrode material for supercapacitors.
First-Principles Study on the Electronic Structure of N-Doped Orthorhombic SrHfO3
Authors: Liu Qi Jun , Liu Zheng Tang , Feng Li Ping , Tian Hao
Published: May 2011

The electronic properties of N-doped orthorhombic SrHfO3 have been calculated using the plane-wave ultrasoft pseudopotential technique based on the first-principles density-functional theory with the local density approximation. From the calculated band structure and density of states, the bandgap reduction is observed due to the presence of the N-2p states in the top of valence bands, which leads to red-shift. Moreover, in order to clarify the charge transfer and bonding properties of N-doped orthorhombic SrHfO3, we have calculated and analysed the charge density.
Microstructure and Mechanical Properties of In Situ Al2O3- Ti(C,N) Composites
Authors: Feng Xiu Mei , Lian Xiao Qing , Jiang Ming Xue , He Yi Ner
Published: May 2011

Al2O3-Ti(C,N)composite ceramics were prepared by in situ aluminothermic reduction and pressureless sintering. The effects of different Ti(C,N) contents and sintering temperatures on microstructure and mechanical properties (bulk density ,apparent porosity and blending strength)of samples were investigated through experiments.The results show that Al2O3-Ti(C,N) composite ceramics with 10 wt.% Ti(C,N) prepared using titanium dioxide and metal aluminum powder as raw materials and sintered at 1300 °C for 3h under a flowing nitrigen stream have good properties ,with bulk density 2.94g/cm3,apparent porosity 26.4%, and blending strength reaches to 28.04 MPa. According to the microstructure analysis,the fine in situ synthesis Ti(C,N) particles are uniformly dispersed in tabular alundum matrix. Ti(C,N) and tabular alundum phases are closely combined and can inhibit grain growth each other,which is benefical in improving the comprehensive properties of composite ceramics.
New Technology with Efficient and Energy-Saving to Prepare Semisolid Alloy Slurry
Authors: Liu Zheng , Liu Xiao Mei
Published: May 2011

Semisolid alloy slurry was prepared by an efficient and energy-saving technology which consists of low superheat pouring and slightly electromagnetic stirring (LSPSES). The effects of the main preparing parameters on the slurry were researched. The results indicate that the slurry to satisfy rhoe-forming needed can be prepared by LSPSES. The pouring temperature and the stirring power remarkablely affect the morphology and size of primary α-Al in semisolid Al alloy slurry. Through the suitable slightly electromagnetic stirring, the pouring temperature can be suitably raised to reach the efficient and energy-saving effectiveness.
Effect of Prior Deformation on Properties of Cu-Cr-RE Alloys
Authors: Guo Zheng Hua , Shuai Ge Wang , Fang Ping
Published: May 2011

The variations of hardness and electrical conductivity of a deformed supersaturated Cu-Cr alloy have been investigated during isothermal aging. The influence of trace rare earth elements (La, Y or Nd) as a second alloying element was also studied. The results showed that the heavily deformed alloys exhibited an instant increase in both hardness and electrical conductivity due to an accelerated precipitation after a short aging treatment. Compared with the solution treated Cu-0.8wt %Cr-0.05wt. %La and Cu-0.8wt %Cr-0.05wt. %Y alloy, the as-cast Cu-0.8 wt. %Cr-0.05 wt. %Nd exhibited a retarded recrystallization which should be attributed to the pinning effect of primary Cr precipitates lying in the grain boundaries. Rare earth elements can act as a useful second alloying element to inhibit recrystallization of the deformed alloys due to the occurrence of some copper-rare earth intermetallic compounds and rare earth oxides.
Numerical Study on Controllable Multi-Band Microwave Metamaterial Absorbers
Authors: Ji Wei Wei , Wang Tao , Nie Yan , Gong Rong Zhou
Published: May 2011

Based on the impedance matching and electromagnetic resonant characteristic of composite materials, we present a single-layer metamaterial absorber consisting of arch copper loop and substrate FR-4, of which the resonant frequency depended on the loop’s geometry perimeter. By combining resonant loops with different dimensions together, we can achieve multi-band absorption. The standard finite difference time domain method was used to calculate the magnitudes of reflectance, and then the induced surface current and power loss distributions were demonstrated to analyze the insight physical picture of the multi-band resonant feature. By optimizing the simulation results, the absorptivities of two absorption peaks are all above 98% when the number of copper loops is two, 95% for three absorption peaks of three loops, and 87% for four absorption peaks of four loops.
Research on MIB Suface Modification of Cr12MoV Cold-Working Die Steel
Authors: Ding Xiao Fei , Zeng Bao Qing , Lin Ai Guang , Xie Zhong Dong , Mu Cheng Xiao
Published: May 2011

Multi-ion beam (MIB) surface modification techniques are used to treat Cr12MoV cold die work steel. The modified layers of steel treated by MIB is improved with low friction coefficient, high wearing resistance and strong adhesion with the matrix through results of hardness, scratch and wearing test. The modified layers include (Ti2N +TiN), (а-Fe+TiN) and (а- Fe(N)+Cr7C3) three layers from surface to inside by analysis of SEM, EPMA and TEM. And the surface layer presents nano-size grain refining. The service life of the Cr12MoV cold die steel treated by MIB can be prolonged 3-5 times longer than the untreated one.
A Novel Anisotropic Electroactive Liquid Crystalline Polyimide Containing Aniline Trimer Segments
Authors: Liu Si Wei , Cao Qiao Ying , Zhang Yi , Chi Zhen Guo , Xu Jia Rui
Published: May 2011

A novel type of liquid crystalline polyimide with good electroactive properties has been successfully synthesized through polycondensation in the component solvent of benzene sulfonyl chloride, dimethyl formamide and pyridine by N,N’-hexane-1,6-diylbis(trimellitimides), p-hydroxybenzoic acid, 4,4'-dihydroxybenzophenone and double amino-capped aniline trimer (N1,N1'-(1,4-phenylene)bis(benzene-1,4-diamine)). The structure of the obtained polymer was characterized and verified. The polymer can be dissolved in the component solvent of phenol and chloroform or DMF, NMP alone, et al. The molecular weight (Mn=1.7×104, Mw=8.2×104，PDI=4.8) was determined by gel permeantion chromatography using DMF as eluent. By combining the excellent properties of both polyimide and oligoaniline, such material could be used in more broad fields. Furthermore, due to the orientation properties of liquid crystalline property, the conductivity of this polymer is anisotropic, with 10-6 S/cm along the shear direction vs. 10-7 S/cm perpendicular to the shear direction.
The Effect of Be and Mn Co-Doping on the Magnetic and Transport Properties of Ferromagnetic Semiconductor Thin Films
Authors: Xiang Gang , Zhang Xi
Published: May 2011

The co-doping effect of Be and Mn have been studied in the ferromagnetic semiconductor (Ga,Mn)As thin films. The measurement of magnetic properties shows that the Be doping decreases the Curie temperatures of the ferromagnetic sample due to defects formation. The transport studies show that the Be incorporation decreases the resistivity of the (Ga,Mn)As thin films. It is found that Be incorporation decreases the planar Hall resistance but increases the resistance transitions in the magnetic samples.
Effects of Film Thickness on Microstructure and Ferroelectric Properties of Bi3.15Nd0.85Ti3O12 Thin Films Prepared by Sol-Gel Method
Authors: Liu Chang Yong , Guo Dongyun , Wang Chuan Bin , Shen Qiang , Zhang Lian Meng
Published: May 2011

Bi3.15Nd0.85Ti3O12 (BNT) thin ﬁlms with different thicknesses (200, 270, 360, 450 and 540 nm) were prepared on Pt/Ti/SiO2/Si substrates by sol–gel method. The effect of film thickness on the microstructure and ferroelectric properties of BNT thin ﬁlms was investigated. All BNT thin films were consisted of a single phase of bismuth-layered perovskite structure. With increasing film thickness, grains gradually became larger, the remanent polarization (2Pr) firstly increased and then decreased, and the leakage current density showed opposite trend. The 360 nm-thick BNT ﬁlm exhibited better electrical properties with 2Pr 26 µC/cm2, coercive ﬁeld (2Ec) 220 kV/cm, dielectric constant 345 (at 1 MHz) and low leakage current density.
Solvent Cutting to Make Superior Coal Tar Pitches
Authors: Zhou Jian Shi , Wei Xian Yong , Dou You Quan , Gong Gui Zhen , Li Peng , Yue Xiao Ming , Chen Bo , Wang Fang Wu , Feng Chao Hui , Zong Zhi Min
Published: May 2011

Using solvents extraction separation system of self-designed make superior coal tar pitches for carbon materials. In proper order choose petroleum ether, methanol and carbon disulfide to cut coal tar into several fractions under different condition. The first solvent can take light components out from coal tar. Then drag out those chemical that contain heteroatom such as nitrogen, sulfide applying the second solvent. The last is to dig out higher molecular weight polycyclic aromatic hydrocarbon from coal tar deeply. Heavy fractions are vacuumed to drive out any solvents. The superior chirpy coal tar pitches for carbon materials acquired.
Electronic Structures and Optical Properties of CuIn1-XGaXSe2 by First-Principle Calculations
Authors: Li Zong Bao
Published: May 2011

First-principle calculations on the electronic structures and optical properties of CuIn1-xGaxSe2(x=0, 0.25, 0.5, 0.75 and 1) reveal that CuIn1-xGaxSe2 are small band gap materials and the ground state is stabiles from x=0 to 1 while the band-gap of the quaternary compound widen, all of that are in good agreement with the experimental results. We find that the obviously double peak structure of the imaginary of dielectric function centered about from 0.9 to 5.0 while a distinct peak appears at about 2.2eV and a smooth increasing with another peak appearing at about 5.5eV for the different content of Ga appearing in the absorption spectrum, all of which indicate the different band gap for the transition.
Effect of Catalysts on Preparation of Sol-Gel Derived Si02 Antireflective Coating
Authors: Wang Yu Cang , Jin Rui Min
Published: May 2011

Based on TEOS system and sol-gel process, together with catalysts, the microstructure of SiO2 particles in the sol is exactly controlled. The films are characterized by ellipsometer and SEM respectively. The experimental results show that adjusting catalytic agent can effectively effect the structure of SiO2 thin film.
Comparative Study on Corrosion Behavior of Zinc-Aluminum Coated Steel under Thin Electrolyte Layers
Authors: Zhao Xiao Dong , Yang Jie , Xing Shao Hua
Published: May 2011

Due to the excellent anticorrosion performance, zinc-aluminum coatings are widely used in a variety of structural applications, and most are exposed to atmosphere especially marine atmosphere. In this paper, weight loss experiment and electrochemical impedance spectroscopy technology were used to comparatively study the corrosion behavior of zinc-aluminum coatings in stimulant marine atmosphere. Experimental results show that the anticorrosion performance of GL coating was better than that of GF coating and the length of drying period had obviously influence on the corrosion behavior of GF and GL coating.
Influence of Dicumyl Peroxide and Maleic Anhydride on the Tensile Properties of HDPE–Calcium Carbonate Composites
Authors: Guo Rui Bao , Yao Jin Shui , Yang Zhi Yong
Published: May 2011

PE is modified basically with inorganic matter (generally CaCO3) and some auxiliaries, but because of the interattraction of the particles, CaCO3 is easy to agglomerate, so we must add some dispersants(generally stearic acid ) ,but some study suggested that, with stearic acid , tensile strength, yield strain and ultimate elongation reduced. But we find that adding dicumyl peroxide and Maleic Anhydride can make up for the defects even increase these properties. As initiator and crosslinker ,dicumyl peroxide is usually used in synthesis of polymers. And is also Maleic Anhydride. However,in this experiment, we add a certain amount of them, dicumyl peroxide initiated Maleic Anhydride to ingraft, also,it initiated the molecular chains of PE to be cross-linked. So, the tensile properties of HDPE–calcium carbonate composites increased obviously, nevertheless ,we must add appropriate amount, if exceeded ,the mechanical properties would reduce.
Correlations between Coating Components and Mechanical Properties of Weld Deposited Metal
Authors: Meng Gong Ge , Chu Ji Jun , Luan Jing Yue , Chen Yong Sheng
Published: May 2011

An electrode coating slag system CaO-CaF2-BaO-TiO2-SiO2 has been designed after analyzing several domestic and abroad basic slag system. In view of uniform design method and computer program, the experiments were arranged. Nine to eleven coating components were taken as independent variables and they were divided into five levels in all twenty-nine experiments. Four mechanical properties and diffusible hydrogen content of weld deposited metal were taken as target functions. The data were analyzed with mathematical and statistic software. The results give the influencing trend figures of coating components on mechanical properties and diffusible hydrogen content and interrelation multinomial mathematic models between independent variables and functions. With these trend figures and mathematic models, the adjusting direction of improving mechanical properties and decreasing diffusible hydrogen content of weld deposited metal can be inquired, and target functions optimization searching have been done.
Lubrication Properties of Aqueous Solutions with Polyethoxylated Ether (PEOE) Added
Authors: Zhang Chao Hui , Liu Si Si , Sun Yue Tao , Liu Jun Ming
Published: May 2011

Aqueous solutions have found broad usages as lubricants, in conjunction with other possible utilizations, such as in metal working and other industries. Due to the inferior lubricity, functional additives are needed to improve their tribological performances among which aqueous surfactants are exclusively included. The film forming property of aqueous solution with polyethoxylated ether added (PEOE) is measured, taking consideration of the influences of the temperature and the concentration. The addition of PEOEs into aqueous solutions will largely increase the film forming capacity. But the concentration has only a minor influence on the lubrication property of the aqueous solutions with PEOEs. The cloud point will strongly alter the film forming characteristics.
Effects of Atomic Oxygen Irradiation on PDMS/POSS Hybrid Films in Low Earth Orbit Environment
Authors: Song Mi Mi , Duo Shu Wang , Liu Ting Zhi
Published: May 2011

In order to improve the atomic oxygen (AO) erosion resistance of polyimide films in low earth orbit space environment, a type PDMS/POSS hybrid coating on polyimide substrate was prepared based on a silanol terminated polydimethylsiloxane (PDMS-OH) and Octakis(trimethylsiloxy)octaprismosilsesquioxane (Q8[Si(CH3)3]8) by copolymerizing process in DMAc solution. The atomic oxygen exposure tests were carried out using a ground-based atomic oxygen simulation facility. The mass loss, surface morphology and surface chemical compositions of PDMS/POSS hybrid films before and after exposure to incremental AO flux were investigated by using microbalance and field emission scanning electron microscopy (FE-SEM) and X-ray photoelectron spectroscopy (XPS), respectively. The data indicated that a silica-rich layer was formed on the surface of the hybrid coating when the coating is exposed to AO flux, which could provide a protective barrier on the surface preventing further degradation of the polymer during extended exposure to AO and obviously improved the AO resistance of polyimide films.
Choice of Electrode Material for Detecting Low Frequency Electric Field in Sea Water
Authors: Song Yu Su , Zhang Kun , Zuo Pan
Published: May 2011

Seven types of electrodes have been selected. DC resistances, AC impedances and voltage difference of the electrode pairs have been studied, according to the requirement of low and extra low frequencies electric fields detection in sea water. The feasibilities of these electrodes used for detecting these signals have been studied and explained on theories. The results show that the all-solid-state Ag/AgCl electrode is the most sensitive electrode with its very low DC resistances, AC impedances and the voltage difference controlled within 20μV, which makes it detecting low frequency electric field accurately.
Preparation of Hexaphenylamine Cyclotriphosphazene and its Green Flame Retardance on Epoxy Molding Compound for Large-Scale Integrated Circuit Packaging
Authors: Yang Ming Shan , Li Lin Kai
Published: May 2011

The hexaphenylamine cyclotriphosphazene (HPACTPZ) was synthesized using titrating technology of hexachlorocyclotriphosphazene solution and the synthesis parameters were investigated, and the structure of HPACTPZ was analyzed by FTIR and NMR in this paper. Using HPACTPZ synthesized in the work as flame retardant, the epoxy molding compound(EMC) for packaging of large-scale integrated circuits with halogen-free flame retardance was prepared. The results have shown that the flame retardance of EMC flame-retardanced by HPACTPZ was up to UL 94 V0 rating(3.2mm) and the oxygen index of the EMC was up to 35.8%, which indicates that HPACTPZ has much better flame retardance for EMC than traditional halogen flame-retardants. Meanwhile, HPACTPZ accelerated the curing reaction rate of EMC, which can be used for manufacturing the quick-curing EMCs or afterward-curing-free EMCs.
Comparison and Thermodynamic Analysis of Crystallinity of Noncrosslinking and Crosslinking Fluorinated Acrylate Copolymers Films
Authors: Chen Hui Qin , Wu Bing , Cai Zhi Qi , Pi Pi Hui , Wen Xiu Fang , Zheng Da Feng , Cheng Jiang , Yang Zhuo Ru
Published: May 2011

In this manuscript two different fluorinated acrylate copolymers films, one was non-crosslinking Stearyl acrylate/2-(perfluorooctyl) ethyl methacrylate (SA/FOEMA) and another was cross-linked SA/2-hydroxyethyl methacrylate(HEMA)/FOEMA/hexamethylene diisocyanate trimers (N3300), were prepared and their crystallinities were investigated by means of X-ray diffraction (XRD) and differential scanning calorimetry (DSC). It can be shown from the XRD results that the value of crystallinities of SA/FOEMA and SA/HEMA/FOEMA/N3300 copolymer were 80.95% and 84.02%, respectively. Based on DSC curves and theoretical thermodynamic analysis , it is indicated that crosslinking can improve crystallinity of copolymer composed of SA and FOEMA.
Synthesis and Electrochemical Properties of Macro-/Microporous Carbon Foams
Authors: Xiong Wei , Liu Ming Xian , Gan Li Hua , Wang Xiao Gang , Xu Zi Jie , Hao Zhi Xian , Liu Hong Lai , Chen Long Wu
Published: May 2011

In this paper, we demonstrated the synthesis and electrochemical properties of macro-/ microporous carbon foams (MMCFs) for application as supercapacitor electrode materials. By using Span 80 and Tween 80 as emulsifiers, resorcinol/formaldehyde solution as aqueous phase, and 1iquid paraffin as oil phase, an O/W emulsion was obtained. Macroporous carbon foams were prepared by the polymerization of the emulsion, followed by drying and carbonization. The macroporous carbon foams then were activated at 1273 K by using KOH as an activated agent to obtain MMCFs. The resultant MMCFs were characterized by scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) analyzer. The results indicate that the MMCFs have specific surface areas of 529-670 m2/g, total pore volumes of 0.27-0.33 cm3/g and possess dual pore size distributions with macropore sizes of 0.5-5.0 μm and micropore sizes of 1.72-1.86 nm dependent on the specific experiment parameters. The hierarchical pore structure is propitious to decreases the diffusion resistance of electrolyte and accelerate the ion transfer within the pore channel, and thus improve the electrochemical properties of MMCFs. The electrochemical properties of the MMCFs have been investigated by cyclic voltammetry (CV) and galvanostatic charge-discharge with a three-electrode system in electrolyte of 6 mol/L KOH solution. The CV curves of the MMCFs show quite rectangular curve shape without observation of obvious oxidation-reduction evolution peaks, suggesting a typical nonfaradic adsorption/desorption reaction. The MMCFs present linear galvanostatic charge-discharge curve under the current densities of 1.0-4.0 A/g and their specific capacitance values are 89-110 F/g. The MMCFs has good electrochemical performance and they are good candidates as electrode materials for supercapacitors.
The Influence of BaF2 Flux Concentration on the Luminescence of Sr3SiO5:Eu2+
Authors: Xu Guo Feng , Liu Quan Sheng , Zhao Li , Cao Dan Dan , Wang Rui , Luo Yu Ping , Guo Zhao , Zhang Xi Yan
Published: May 2011

Silicate strontium phosphor for white light LEDs was synthesized by high temperature solid-state method. The structure, surface, excitation and emission spectra of Sr3SiO5: Eu2+ phosphor which contain different mass fractions of BaF2 were measured. The results show that BaF2 quantity affects the structure, surface and spectra of Sr3SiO5: Eu2+ sample. The sample has the best properties when the BaF2 concentration comes to 2.0wt%. The structure of sample is tetragonal phase Sr3SiO5. The emission and excitation spectra peaks locate respectively at 575nm and 537nm. The samples can be excited by InGaN blue chip. The emission peaks appeared apparent red shift with the increase of BaF2 concentration. A white light emission spectrum with good color rendition was obtained by coupling the phosphor with blue chip.
Manufacturing Technique and Property Evaluation of Polypropylene/ Carbon Fiber Composite Braids
Authors: Lin Jia Horng , Chen Jin Mao , Lin Ching Wen , Hsing Wen Hao , Hsu Yu Chia , Lou Ching Wen
Published: May 2011

In this study, carbon fibers (CF) were braided with polypropylene (PP) fibers on a 16-spindle braid machine, forming the PP/ CF composite braids. The composite braids with different levels of strength could be obtained by changing the speed of the yarn turntable and volume gauze. The composite braids with optimum tensile strength then received the thermal treatment, which melted the PP fibers to wrap the CF more tightly, stabilizing the structure of the composite braids. According to CNS 11623 (Tensile Properties of Geogrids by the Single), the composite braids were thermal-treated at 170 °C, 180 °C and 190 °C for1 min, 2 min and 3 min, determing the influence of thermal temperature and duration on the tensile strength of PP/ CF composite braids.
Study on Friction Stir Spot Welding Procedure of AZ31 Magnesium Alloy
Authors: Ding Cheng Gang , Guo Chuan Jun , Quan Gao Feng , Wu Feng
Published: May 2011

The study has examined the influence of FSSW (friction stir spot welding) parameters (rotation speed, downward compression and welding period) on mechanical property (shear resistance force) by conducting FSSW experiments on 3mm-thick AZ31 magnesium alloy plates under the orthogonal design. According to the experiment result, welding period is the major factor that decides the shear resistance force of FSSW joints, optimum welding parameters are: rotation speed(RS) 2450r/min, welding period(WP) 8s, downward compression of the tool shoulder(DCTS) 0.2mm. Microstructure observations show that tiny and even equiaxial grains are formed in WN (Weld nugget zone) and coarse grains with uneven sizes are formed in TMAZ(thermo-mechanically affected zone) and HAZ (Heat affected zone).
A Novel Technique for Preparation of the Fluorescence Sensor Based on Covalent Immobilization of 1-Aminopyrene
Authors: Tan Shu Zhen , Zeng Pu Ni , Cao Zhong , Xia Jiao Yun , Li Wei
Published: May 2011

A novel technique to covalently immobilize indicator dyes with terminal amino groups for preparing optical sensors is investigated. Au nanoparticles are used as bridges and carriers for anchoring indicator dyes on the surface of a quartz glass slide. 1-Aminopyrene (AP) was employed as an example of indicator dyes and covalently immobilized onto the outmost surface of the glass slide. First, the glass slide was functionalized by (3-mercaptopropyl) trimethoxysilane (MPS) to form a thiol-terminated self-assembled monolayer, where Au nanoparticles were strongly anchored via covalent link. Then, 16-mercaptohexadecanoic acid (MHDA) was self-assembled to bring carboxylic groups onto the surfaces of Au nanoparticles. A further activation by using 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) converted the carboxylic group into succinimide ester. Finally, the active succinimide ester was reacted with 1-aminopyrene (AP). Thus, AP was covalently immobilized to the glass slide and an AP-immobilized sensor was obtained. The resulting sensor was used to determine rutin based on fluorescence quenching. It showed a linear response toward rutin (R) from 5.0 × 10-7 to 6.0 × 10-4 mol L-1 with a detection limit of 2.0× 10-7 mol L-1. This AP-immobilized sensor has very satisfactory reproducibility, reversibility, rapid response and no dye-leaching.
Fast Analysis of Nitrobenzene by Nitroreductase Modified Electrode
Authors: Liu Chen Ming , Cao Hong Bin , Li Yu Ping , Zhang Yi
Published: May 2011

Nitroreductase (NR) was modified on glass carbon electrode and used in nitrobenzene analysis. Both cyclic voltammetry (CV) and triple potential step chronocoulometry (TPSC) with a narrow potential step interval were used. The modification of nitroreductase improved the sensitivity and selectivity of nitrobenzene detection. Both the peak area and peak current were examined for quantitative analysis, showing a linear relation between nitrobenzene concentration and peak area, and a logarithmic relation for peak current, with correlation coefficients of 0.9981 and 0.9993, respectively. Statistical tests to evaluate the reliability of TPSC showed that there was no evidence of systematic error, and it was not significantly different from CV or high performance liquid chromatography (HPLC). The new method could avoid most interferents, showing good selectivity.
Modeling of Grain Growth with Second Phase Particle Pinning by Cellular Automata Method
Authors: Li Hong Zhong , Ma Xiao Fei
Published: May 2011

A model for grain growth simulation, in the presence of the second phase particles, is established with the help of a Cellular Automata method. The effect of the time when the second phase particles are introduced on grain growth is simulated. The simulation results show that the second phase particles inhibit the grain growth and the earlier the particles are introduced, the better the pinning effect.
Corrosion and Ni-P Coating Protection of Carbon Steel Used in Hypochlorite Disinfection Solution
Authors: Sun Jie , Yan Rui , Liang Ting , Ji Zhuang Zhou , Meng Jin Hong
Published: May 2011

The corrosion process was analyzed for carbon steel when used in Ca(ClO)2 hypochlorite Disinfection Solution. The corrosion resistance of Ni-P electroless coating was characterized by electrochemistry method. From the results, it was shown that the corrosion reaction can occur spontaneously according to the caculation result. The corrosion products existing on the carbon steel surface were loose and porous. The main conpositions of the products are about iron oxide. For Ni-P coatings, the corrosion current densities reduced gradually with the increasing of electroless plating time.
Effects of Annealing Parameters on Recrystallization of AZ31 Magnesium Alloy Processed by Continuous Rheo-Extrusion
Authors: Guan Ren Guo , Zhao Zhan Yong , Cao Fu Rong , Huang Hong Qian , Dai Chun Guang , Zhang Qiu Sheng
Published: May 2011

AZ31 magnesium alloy profiles were prepared by continuous rheo-extrusion, and effects of annealing temperature and time on recrystallization of AZ31 magnesium alloy were investigated. The results reveal that when the profile is annealed in the temperature range from 200°C to 300°C, the moving velocity of grain interface with different dislocation densities on both sides increases with increasing annealing temperature, which is favorable to the formation of crystallized nucleus in the region in which interface sweeps over. As a result, the time required by the accomplishment of recrystallization becomes short. After recrystallization finishes, continuous temperature rise or prolonged holding time result in grain growth. When the profile is annealed at elevated temperature, with the prolongation of holding time, the grain growth rate accelerates obviously, and hence recrystallized microstructure becomes coarse. When the profile is annealed at lower temperature, the grain growth rate becomes small, and the time required by the accomplishment of recrystallization is long, but recrystallized microstructure is fine and homogeneous. When the profile is annealed at 250°C for 4h, average recrystallized grain size is 15μm.
Flotation Desulfurization of High-Sulfur Bauxite with Ethyl Thio Carbamate as Collector
Authors: Wang Xiao Min , Zhang Ting An
Published: May 2011

The desulfurization of high-sulfur diasporic bauxite （from China） with flotation process and ethyl thio carbamate as collector was studied, and the effects of flotation time, pulp density, pH value and particle size of ores were examined. The experimental results indicate that the sulfur in bauxite was successfully decreased through flotation. The sulfur content of bauxite was lowed to 0.66% under the condition of pH value 4, the dose of flotation agent ethyl thio carbamate 0.5kg/t, frother 20g/t, flotation time 15 minutes, pulp density 10%, the particle size of ores ≦0.09 mm, and the reclamation of Al2O3 is 90.16% as well. The flotation kinetics of flotation desulfurization was also studied.
The Effect of Diacids and Diols on the Lipase-Catalyzed Synthesis and Properties of Biodegradable Functional Polyester
Authors: Yao Da Hu , Li Guang Ji , Zhang Yu Qing
Published: May 2011

Biodegradable polyesters with free hydroxyl groups were synthesis by the lipase-catalyzed polycondensation of L-malic acid with different diacids (succinic acid, adipic acid and sebacic acid) and diols (ethandiol, 1,4-butanediol, 1,6-hexanediol and 1,8-octanediol). The molecular weight (Mw) of the copolymers was affected by the alkylene chain lengths of diacids and diols. It was found that diacids and diols with longer alkylene chain lengths have a higher reactivity than that of shorter chain-length diacids and diols. The crytallizability of the copolymers were affected by the alkylene chains length of diacids and diols. The crytallizability decreased with the decreasing of the alkylene chains length of diacids and diols.
Transparent Hydrophobic Fluorocarbon Coatings Fabricated on Regenerated Cellulose Films by RF Magnetron Sputtering
Authors: Zhang Yu Hui , Ji Quan , Hu Yan Fang , Sun Xi Quan
Published: May 2011

A series of novel transparent hydrophobic regenerated cellulose (RC) films were coated with a fluorocarbon polymer by radio frequency magnetron sputtering. The effect of sputtering power and pressure on the surface morphology, chemical composition, contact angle and visible light transmittance of the coated films were investigated by atomic force microscopy, X-ray photoelectron spectroscopy, contact angles and ultraviolet-visible spectroscopy. The surface roughness increased as the sputtering power and pressure increased. The fluorocarbon coatings contained four components: -CF3, -CF2-, -CF- and -C-. The relative proportions of the saturated components significantly affected the hydrophobicity of the coatings. After applying a fluorocarbon coating, the static contact angle of the coatings was greater than 90°, and the substrate RC film was transformed from hydrophilic to hydrophobic. The visible light transmittance was greater than 80% when the roughness of the coating was less than 100 nm. The optimal sputtering conditions used a power between 80 and 150 W, and pressure between 1.0 and 3.0 Pa.
Dynamically Regulate and Control Complicated Auto Panel Uniform Forming
Authors: Zhao Mao Yu , Chen Qian Wang , Xue Ke Min , Li Ping
Published: May 2011

A complicated auto panel forming is nonuniform plastic course and it is critical for dynamic reasonable the process parameters to avoid and decrease non-crackle, non-wrinkle, thickness uniformity forming defects. So, the forming of auto panel right beam is simulated by finite element software while the blank holder force and depth, die radius, punch radius of draw bead are independent variables, acquiring forming quality object (the data about the crack, winkle and the thinning)by orthogonal experiment. And the weight of multi-object is calculated by analytic hierarchy process, the grey relational generating and the grey rational grade of multi-objective are all calculated by the grey theory system while forming course is subdivision.Then, the dynamic optimization process parameters of blank holder force and draw bead restrain force are attained. Furthermore, employing the dynamic regulation-control optimization data to numerically simulate the auto panel forming. The conclusion demonstrates that the forming quality is obviously increased by the optimized process parameters.
Counter-Ion Induced Morphological Control of Polypyrrole/Fe3O4 Nanocomposites in the Presence of Surfactant CTAB
Authors: Yang Chun Ming , Xiong Dong Bai , Wang Hong Bo
Published: May 2011

We report a facile and novel route to in-situ growth of conducting polypyrrole (PPy)/Fe3O4 nanocomposites via a counter-ion induced method, in which the cationic surfactant CTAB was used as a soft template, ammonium persulfate (APS) or FeCl3 was used as an oxidant, and organic acids were used as a configuration “directing” agent. The as-synthesized nanocomposites were characterized by TEM, XRD and the measurements of their electromagnetic properties. Experimental results show that both the kind of oxidant and the size of counter-ions in the polymerization system play the key roles in the fabrication of the morphologies of the final PPy/Fe3O4 nanocomposites. A uniform core-shell spherical nanostructure was formed when FeCl3 was used as the oxidant, whereas the string-bead nanostructure could be obtained when APS was used instead. The size of the counter-ions during the connection of micellar molecules could directly induce the formation of the PPy/Fe3O4 composites with various morphologies from spherical nanoparticles, nanofibers or string-bead nano-network to microtube structures. Meanwhile the loading amount of Fe3O4 ferrofluid would not only determine the diameter size of the string-bead nanostructures, but also the electromagnetic properties such as the microwave absorbing capacity of the resulting nanocomposites.
Urea Reactor Explosion Accident Stress Corrosion Analysis
Authors: Chen Zhong He , Wang Wei Qiang , Song Ming Da , Dong Ning Ning
Published: May 2011

In order to find out the accident urea reactor explosion reasons, based on the accident investigation, the reactor structure was anatomyed, the macroscopic and microscopic fractures were sampled and observed, The results show that the trace sodium, potassium and other alkaline ions content in the liquid of liquefied steam is the stress corrosion medium reason; the leak detection pine and the 16MnR laminate connecting with screw joint is the structural reasons; typical stress corrosion had occurred on the accident urea reactor cylindrical segment base metal and welding. Some important suggestions were given
Inhibition of the Growth of Au Nanoparticles for Xanthine Sensing: Spectral and Electrochemical Studies on the Interactions between Xanthine and Au(III) Ions
Authors: Pan Hong Cheng , Li Dun Nan , Liu Jiang Tao , Li Jian Ping , Zhu Wen Yuan , Cui Rong Jing
Published: May 2011

The role of xanthine in the growth process of Au nanoparticles (AuNPs) was clarified by Uv-vis absorption spectra, resonance light scattering (RLS) spectra, cyclic votlammetry (CV), and differential pulse voltammetry (DPV). In a growth solution containing 0.01 M phosphate buffer solution (PBS, pH 7.4), 24.3 μM HAuCl4, and 2 mM cetyltrimethylammonium chloride (CTAC), the AuNPs were produced by tannic acid (TA) reduction. The growth of AuNPs was inhibited by the addition of xanthine. The plasmon absorbance band of AuNPs is blue shifted, indicating that larger sized AuNPs were grown in the presence of xanthine. Both the absorbance at 555 nm and RLS intensity at 652 nm of the grown AuNPs decreased linearly with increasing concentrations of xanthine. The linear regression equation are A=1.865−0.016 Cxanthine and I=397.8−4.617Cxanthine for absorbance and RLS intensity, respectively. The results of CV and DPV reveal that the inhibition effect of xanthine on the growth of AuNPs may attribute to the formation of xanthine-Au(III) complex. The conditional stability constants of the complexes were determined to be 2.22×105.
Study on Cross Section Geometry of Preform for the Forming Laws of a Symmetrical Rib-Web Component
Authors: Wang Meng Han , Xu Zhi Min , Li Yu Feng , Zhou Jie
Published: May 2011

In order to reveal the forming laws，eliminate the forming defects appearing in the typical aluminum alloy web-rib parts，two types of preforms have been used in the final forging with numerical simulation software.Based on the simulation，the comparisons of metal flow，effective strain distribution are obtained between the two types of preforms applied in the final forging process，the forming laws of a symmetrical rib-web component have been obtained ,and the forming mechanism of defects often happened in web- rib parts also has been analyzed,the relationship between the fillet radius and metal flow velocity/ final load was obtain. The results show that the fiber breaking,vortex could be avoided，a high forming quality of rib-web part could be gained by the method of using the thin web-high rib preform in finish-forging.