bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation and Characterization of Nanocrystalline Ce-Containing Layered Double Hydroxides
Authors: Chen Chun Xia , Zhang Yu , Zhao Han Qing , Peng Jin Song , Li Bin
Published: May 2011

Ce-containing Layered Double Hydroxides (Ce-LDHs) were prepared by conventional and microwave-assisted crystallization method, which were denoted as Ce-LDHs-A and Ce-LDHs-B, respectively. The dispersibility of Ce-LDHs-B is much better than that of Ce-LDHs-A; the particles of Ce-LDHs-B with particle size ranging from 20 to 70 nm are smaller than that of Ce-LDHs-A with sizes around 50-300 nm. The effect of the cerium to aluminum molar ratios, microwave crystallization time and reaction temperature on the structure of Ce-LDHs was also investigated. The results show the excessive Ce into LDHs causes distortion of the samdwich, the damage of the LDHs structure becomes more and more serious with increasing the proportion of Ce/Al. The structure of Ce-LDHs becomes more and more perfect with the increasing of the microwave crystallization time and reaction temperature.
Process Structure and Properties of Bi-Shrinkage Yarns Spun by one-Step Spinning Process
Authors: Xue Yuan , Yang En Long , Tang Cheng Tan
Published: May 2011

Aggregation structure and properties such as crystallinity, orientation, mechanical properties, boiling water shrinkage of high-shrinkage component, low-shrinkage component, and the bi-shrinkage yarns which are spun at different process conditions are characterized and tested. The high-shrinkage component and low-shrinkage component spin individually, the bi-shrinkage yarns spun by one-step spinning process. The research indicates that with the spinning speed increases, the degree of crystallinity and orientation of the high-shrinkage component increases, and its tensile strength increases, elongation at break decreases, boiling water shrinkage attain the highest value when the spinning speed is 3,000 m/min; With draft ratio decreased, the orientation, crystallinity, tensile strength, initial modulus of the low shrinkage component decrease, and its elongation at break, boiling water shrinkage increases; as the draft ratio decrease, BSY crystallinity decreased, orientation first increases, then decreases, strength, initial modulus decrease slightly, boiling water shrinkage increases; H1 increases from 80 °C to 95 °C, BSY crystallinity gradually increased; degree of orientation decrease, strength, initial modulus increases and elongation decreases, boiling water shrinkage increases firstly,and decreases slightly afterwards; with the H2 temperature increases, BSY crystallinity increase, orientation first increased and then decreased slightly,the tensile strength reduce a little, elongation at break increase, initial modulus decreased, boiling water shrinkage decreased.
Microstructural Study on Ni-Based Alloy Coating on Plain-Carbon Steel Substrate by Hot Dipping Process
Authors: Lin Tao , Wang Li Sheng , Shao Hui Ping , Guo Zhi Meng
Published: May 2011

Ni brazing alloy coating on soft metal substrate has been made extensively with different hard-facing processes. Among various hard-facing processes, hot-dipping has rarely been investigated as an inexpensive technique. In this study, thick Ni-Cr-Si-B-Fe alloy coating (>3 mm) has been made successfully on the plain carbon steel substrate with hot-dipping process. Microstructure and phase identification have been made to the coating with SEM and XRD. It was found that the Ni brazing alloy coating has good binding steel substrate with defect free. Four regions across the thickness of Ni brazing alloy coating, due to solidification conditions upon hot-dipping, have been identified with distinguished microstructure. The main phases of the coating include hard phases of CrB, Fe2B, and Cr23C6 dispersed in g(Fe,Ni) matrix.
The Preparation, Characterization, and Photocatalytic Activities of Co-TiO2
Authors: Xie Ying Na , Wang Zheng De
Published: May 2011

Photocatalytic degradation of methyl orange in water was examined using Co-doped TiO2 nanoparticles. These photocatalysts were synthesized by a sol–gel method from titanium tetra-isopropoxide with different concentrations of Co(III) dopant and calcination temperature at 600°C. The samples were characterized by XRD, DRS, TEM analysis. The XRD results showed that the anatase-to-rutile phase transformation was greatly inhibited by Co ion doping. The increase of Co doping enhanced “red-shift” in the UV-vis absorption spectra. The TEM images confirmed the dopants suppressed the growth of TiO2 grains. The photocatalytic activity of the nanoparticles under UV light was investigated by measuring the photodegradation of methyl orange solutions. Parameters affecting photocatalytic process such as the dosage of catalyst, dopant and methyl orange concentrations were investigated. The degradation process was optimized using a Co concentration of 1.0 mol%, 30mg Co-doped TiO2 and MO concentration of 10mg/L.
Finite Element Study on Temperature Distribution of Curing of Fully Enclosed Adhesive Joint
Authors: Lu Zhi Guo , Lin Jian Ping , Hua Dan Dan
Published: May 2011

The bonded structures in vehicles are usually in different enclosure conditions. A finite element (FE) model, based on fluid-solid coupling method, has been established for analyzing the temperature distribution of adhesive single-lapped joint when curing in a closed enclosure. The heat transferring process of the adhesive joint in an exposed environment has also been executed for comparison purpose. The FE temperature results of both joints are validated by experiments. It has been found that the joint temperature in a closed enclosure rises much more slowly compared with the joint in an exposed environment within the curing process. Due to the thickness variation along the adhesive joint, it can be observed on both joints the lap area always obtains the lowest temperature while the joint ends obtain the highest ones.
Effect of Si Addition on the Microstructures and Mechanical Properties of TiAl Intermetallics
Authors: Zhu Jian Feng , Yang Wen Wen , Li Shao Dan
Published: May 2011

TiAl/Ti5Si3 in situ composites were successfully fabricated by reactive hot-press method from powder mixtures of Ti, Al and Si. The influence of the Si addition on the microstructures and mechanical properties of TiAl/Ti5Si3 composites was investigated in detail. The results show that an appropriate amount of addition of Si refined the matrix structure obviously due to the in situ formed Ti5Si3, and as a result, the flexural strength and fracture toughness of the composites are modified. When the Si content is 1.82 wt %, the flexural strength and the fracture toughness reach the maximum value of 685.67 MPa and 9.02 MPa·m1/2, respectively. The enhancing mechanism was also discussed.
Study of Friction Stir Spot Welding of Steel/ Magnesium
Authors: Wang Xi Jing , Li Bo Qiang , Zhang Chang Qing
Published: May 2011

Dissimilar metal of Steel and Magnesium alloy by friction stir spot welding is studied. Based on using orthogonal test method to optimize the process parameters and get satisfactory joint, SEM is used to observe the features of joint, fracture morphology, and XRD is used to determine the joint phase, and the results show that: the design of rotating tool without pin is reasonable and it can form satisfactory joints without keyhole for spot welding; spot welding nugget zone on the magnesium side shows the phenomenon of melting and solidification in the range of hundreds microns, and its microstructure appears a structure of dendrites; The fracture mode of spot welding joint is a mixed mode of cleavage and dimpled rupture.
Study of Lost Foam Casting of Reaper Underpan
Authors: Li Li Jun , Zhou Jian , Gao Zi Cheng , Hu Yi Hua , Cheng Ke
Published: May 2011

For obtaining higher quality casting, the lost foam casting is used to produce reaper underpan. While the raw materials are selected, the fireproof coating and sand are chosen well, the sand box is designed according to the technology, pouring system is calculated, under the above operation strictly, such as air hole can be avoided.
The Optimum Technological Parameters and Properties of LDPE/LLDPE/Nano-Mg(OH)2 Systems
Authors: Guo Yu Hua , Guo Jian Jun , Huang Zhen , Teng Li Jun
Published: May 2011

Nano-structured magnesium hydroxide (nano-MH) has been added into LDPE/LLDPE, the technological parameters, flame and mechanical properties, M.F.R. of LDPE/LLDPE/nano-MH samples have been examined. It is indicated two time extruder pelletization is a good technological route, which can make nano-MH disperse evenly in PE. The optimum rotational speed of screws changes from 37 to 42 rad/min, the die pressure changes from 35 to 61.5 bar. Nano-MH has good flame retardant and smoke suppressing properties. The samples added 60% nano-MH can reach UL94 FV-0 flame retardant rating. When nano-MH content is more than 40%, no smoke emits. With nano-MH content increases, the tensile strength, impact strength, elongation and M.F.R decreases, Young’s modulus increases.
The Study on the Carbon Deposition in H2-CO Mixtures
Authors: Geng Shu Hua , Ding Wei Zhong , Guo Shu Qiang , Fang Zhan , Lu Xiong Gang
Published: May 2011

Iron ore reduction and carbon deposition under H2-CO mixtures were investigated by using the non-isothermal method. Iron ore in three different configurations were used in this work: pellet, coarse granularity particles and fine granularity particles. The reduced samples were characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM) and accelerated surface area and porosimetry System(ASAP 2020M+C). In pure CO, the carbon deposition increases with decreasing of the sample size. In H2-CO mixtures, the rate of carbon deposition is accelerated dramatically. Morphologies of samples treated in different reducing ambinent were investigated. Specific surface area of the treated sample increases with higher level of carbon deposition.
A Comparative Study of Corrosion Related Electro-Magnetic Field Control Effect
Authors: Wu Jian Hua , Xing Shao Hua , Liang Cheng Hao , Yan Yong Gui
Published: May 2011

The corrosion related electro-magnetic signature is easily detected by modern sensor deployed in mine and other signal measurement system, so the importance of reducing is rapidly growing today. The eliminating effect of shaft frequency signature by shaft insulating technique, passive grounding technique and active grounding technique was comparatively studied by physical scale model (PSM), and their influence on static electromagnetic signature was also studied by boundary element method (BEM). Simulation results suggested that active shaft grounding technique was the best way for eliminating shaft frequency signature, but static electromagnetic signature was stronger than that when the shaft was insulated from hull.
Thermal Decomposition of Wood Treated with Silicates by Thermogravimetry–Mass Spectrometry
Authors: Qu Hong Qiang , Wu Wei Hong , Wang Chun Zheng , Liu Xin , Yin Chun Meng
Published: May 2011

The thermal decomposition of wood treated with a series of silicates was characterized by thermogravimetric (TG) analysis, differential thermogravimetry (DTG), and thermogravimetry–mass spectrometry (TG–MS) analysis. The addition of these chemicals caused a decrease in the decomposition temperature, a reduction in weight loss, and an increase in the amount of char produced. The results showed that ion current intensity and ion peak area of the typical representatives of incombustible ion such as m/z = 18 and 44 MS signals were increased by the flame retardants but the inflammable ion such as m/z =12 and 28 MS signals were decreased at the meantime, which indicate that the flame retardants can significantly enhances the dehydration and inhibits the deploymerisation reaction of wood.
The Preparation and Application of the Cationic Biopolymer Based on Xylan-Rich Hemicelluloses from Agricultural Biomass
Authors: Ren Jun Li , Peng Xin Wen , Peng Feng , Sun Run Cang
Published: May 2011

During the last few years increasing attention has been paid to the exploitation of hemicelluloses as biopolymer resources because they are available in very large amounts in organic wasters from renewable forest and agricultural biomass. The efficient method to prepare the cationic biopolymers based on xylan-rich hemicelluloses from agricultural biomass has been developed in this paper. These biopolymers with cationic functional groups, having many good properties such as solubility, bio-degradation, cationic or ampholytic polymers, were synthesized by the chemical modification of sugarcane bagasse xylan-rich hemicelluloses with CHMAC and preferably with ETA in different media. These biopolymers based on xylan-rich hemicelluloses with the degree of substitution (DS) up to 0.55 could be obtained by varying the molar ratio of ETA or CHMAC to anhydroxylose units in hemicelluloses from 0.5 to 3.0. 13C NMR confirmed that cationic groups were grafted onto the backbone of hemicelluloses. In addition, their applications in papermaking as dry strengthen agent were investigated. It was found that these biopolymers could obviously improve the physical properties of hand sheets formed from old corrugated container pulp fibres. These results mentioned above highlight the remarkable potential for using the hemicelluloses-based biopolymers as wet end additives in papermaking.
Microstructure and Texture Evolution during Equal Channel Angular Extrusion of Pure Copper: Effect of Strain Rat
Authors: Zhang Guo Ping
Published: May 2011

Effect of strain velocity on the refinement of severe plastic deformation structure of ECA pressed pure copper was studied using transmission electron microscope(TEM) and electron back-scattered diffraction (EBSD) analysis. Formation mechanism of unltra-fine grain with high angle boundary was discussed. It was found that exceedingly fast stain rate can significantly increase the fraction of high angle boundary, up to 76%, and make grain refine further, up to 0.23μm.
Preparation and Magnetic Properties of Ce-Doped Strontium Ferrite Films
Authors: Li Yu Qing , Huang Ying , Qi Shu Hua , Niu Lei , Niu Fang Fang , Zhang Yin Ling , Wu Yan Fei
Published: May 2011

We have found that La substitutions can improve the magnetic properties of the strontium ferrite films without reducing the saturation magnetization. In this work, SrCexFe12-xO19 nanocrystalline films (x=0, 0.2…0.8) with high coercivity were synthesized and deposited on SiO2 substrate by sol-gel method and sintering at 900 OC for 2h. The films were characterized by various experimental techniques including X-ray diffraction analysis (XRD), Field Emission Scanning Electron Microscope (FESEM), Vibrating Sample Magnetometry (VSM) and vector network analyzer. The results show that with the increasing content of cerium the coercivity of the films improves greatly and reach the maximum 6678.78 Oe at x=0.2, which is larger than La-doped strontium ferrite films, however the saturation magnetization decreases a lot. In the frequency range of 11.5-12 GHz the electromagnetic properties of the Ce-doped strontium ferrite films are better than La-doped at x=0.2.
Effect of Cold Rolling on Thermal Stability of Zr 55 Al10Ni5Cu30 Bulk Metallic Glass
Authors: Hu Man Hong , Hu Yong
Published: May 2011

The effect of cold rolling on thermal stability of bulk Zr55Al10Ni5Cu30 metallic glass at room temperature had been investigated by means of X-ray diffractometer, high-resolution transmission electron microscope and differential scanning calorimeter. A number of the cold rolling processes were carried out to obtain different thickness reduction in specimens with the same original size. The XRD patterns of cold rolled specimens with thickness reduction up to 95% showed no clear difference with that of completely amorphous specimens. The relationship of the deformation with the thermal parameters of cold rolled specimen indicates that with the increase of thickness reduction, the glass transition temperature decreases obviously and the crystallization onset temperature and peak temperature decreases slightly. At the same time, the enthalpy of crystallization peak keeps almost constant during rolling. These results have revealed that cold rolling deformation has an apparently effect on the glass transition process but slightly effect on the crystallization process of Zr55Al10Ni5Cu30 BMG.
A Comparative Study of Potentiostatic and Potentiodynamic Method in the Synthesis of MnO2 Films for Electrochemical Capacitors
Authors: Kong Ling Bin , Bai Rui Juan , Luo Yong Chun , Kang Long
Published: May 2011

Nanostructured ε-manganese dioxide films are deposited directly on three-dimensional nickel foam (NF) from 0.25 M Mn(CH3COO)2 by means of the potentiostatic method (PSM) and potentiodynamic method (PDM). The prepared MnO2 films are characterized by X-ray diffraction and scanning electron microscopy. The electrochemical properties of MnO2 films are investigated by cyclic voltammetry (CV), charge-discharge tests, and alternating current (AC) impedance spectroscopy. The results show that the PSM-MnO2 films exhibit higher specific capacitance and better high-rate discharge ability, which are more promising for applications in supercapacitor than PDM-MnO2 films. The specific capacitance of PSM-MnO2 films is about 664 F g-1 at 5.5 A g-1, which is higher than many reported values.
Study on the Mechanical Behavior and Microscopic Mechanism of Explosive Working of High-Manganese Steel
Authors: Ding Cheng Gang
Published: May 2011

This paper has examined the hardening effect and mechanism of explosive working on high-manganese steel. According to the experiment result, the surface hardness of high-manganese steel is improved greatly after explosive working and the hardened depth exceeds 40mm. The surface hardness and hardened depth increase slightly, the tensile strength is improved and ductility is reduced after three times of explosion. Charpy impact test demonstrates that it has still high ductility, the fatigue performance isn’t inferior to that before the explosion, the abrasive resistance is higher than that before the explosion and macroscopic residual deformation is extremely small. Such changes are related with the internal stress and changes of metallographic structure after explosion. After explosion, the surface is at stress state and the metallographic structure still retains the single-phase austenite matrix; and it produces high-density dislocation, stacking fault, cross-slip, lattice torsion, twin-crystal and refinement of austenite crystal grains.
Study on PTH/PANI/AC Composites as Electrode Materials for Supercapacitors
Authors: Gao Feng Ge , Tian Yan Hong , Zhang Xue Jun
Published: May 2011

Polythionphene (PTH)/polyaniline (PANI)/activated carbon (AC) composites as electrode materials for supercapacitors were synthesized by in-situ polymerization of thionphene on PANI/AC. The surface morphology and the molecular structure of the composites were examined by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The electrochemical performances were tested by cyclic voltammetry, Galvanostatic charge-discharge and electrochemical impedance spectrometry. Results show that the PTH/PANI/AC composites exhibit better large current charge-discharge performance and higher capacitance than those of PANI/AC. The capacitance value of the composites would reach 597.4 F/g. The PTH/PANI/AC composites also have better cycle stability than that of PANI/AC.
Simulation Research of the Effect of Thermal Reflow Processing Parameters on the Profile of Micro-Spherical Structure
Authors: Jiang Bing Yan , Chen Lei , Li Dai Bing , Kirchberg Stefan
Published: May 2011

In this paper reflow process is integrated into LIGA process in order to realize three dimensional fabrication. The melting and deformation process of photoresist, which has an initial cylindrical shape of D500μm and h66μm, and the influence of various processing parameters on the height of formed microlens, is simulated with Marc. The optimum processing parameters combination is obtained by orthogonal experiment method and the influence of different processing parameters on the height of micro-spherical structure is studied with single factor experiment method. The results showed that the optimum processing parameters combination was 1°C /s for heating rate, 110°C for heating temperature and 45min for holding time; the significance of processing parameters on the micro-spherical structure’s height can be ordered in holding time＞heating rate＞heating temperature.
Preparation and Characterization of Paraffin/PMMA Core/Shell Structured Microcapsules
Authors: Ma Su De , Song Guo Lin , Miao Zong Cheng , Wang Deng Wu
Published: May 2011

Microencapsulated phase change material (MEPCM) was successfully prepared by using paraffin as the core material and PMMA as shell material. Both raw materials are innocuous, cheap and rich in resource. The influences of the key factors (i.e. emulsifier, stabilizer, concentration of the oil phase) on synthesis reaction were systematically evaluated. Conditions of synthesis reaction were also optimized. The relevant research results indicate that the prepared microcapsules are regular spheres with smooth and compact surface. The diameter of these spheres ranges from 1 to 2 mm. No obvious overcooling or overheating phenomena can be observed even when the content of paraffin of MEPCM reaches approximately 50 wt%. TGA analyses indicate that the heat resistance of the microcapsule increases by 10 °C compared to the pure paraffin. Accelerated thermal cycling tests also verify that the MEPCM displays good thermal reliability. The MEPCMs synthesized in the current study have potentials for thermal energy storage purposes such as PCM slurries, textiles and building materials.
Calculation of the Viscosity of Zr-Based Metallic Glass Alloys
Authors: Li Hui Qiang , Liu Long Fei
Published: May 2011

With the effects of electronic structure and atomic size being introduced, a revised model to calculate the viscosity of the bulk metallic glass alloys was proposed and the viscosity of ternary Zr-Al-Cu, Zr-Ni-Al and quaternary Zr-Al-Ni-Cu systems are calculated in this paper, and the computed results agree well with the empirical one. The sequence of viscosity of different systems is: VZr-Al-Cu <VZr-Al-Ni<.VZr-Al-Ni-Cu. To Zr-Al-Cu and Zr-Ni-Al, the highest viscosity locates in the composition range of XZr=0.37-0.86, XCu=0-0.40 and XZr = 0.45-0.79, XAl = 0.12-0.50, respectively. And to the Zr-Ni-Al-Cu system with 66.67% Zr, the highest viscosity is obtained in the region of XAl= 0.63-0.80, XNi = 0.14-0.24.
Influence of Partial Substitution of Ba2+ for Sm3+ on the Structure and Electrochemical Properties of Sm 0.5-xBaxSr0.5Co0.8Fe 0.2O3-δPerovskite
Authors: Wang Yan Hua , Song Xi Wen , Zhou Fen , Gao Jian Quan , An Sheng Li
Published: May 2011

Sm0.5-xBaxSr0.5Co0.8Fe0.2O3-δ powders were synthesized by a sol-gel method. The crystal structure and thermal expansion coefficient of Sm0.5-xBaxSr0.5Co0.8Fe0.2O3-δ (SBSCF, x=0.00, 0.05, 0.10) were investigated. All samples were the perovskite structure with an orthorhombic symmetry and exhibited a similar thermal expansion behavior. The electrochemical properties of SBSCF-SDC composite cathodes were studied using A.C. impedance method. The substitution of Ba2+ for Sm3+ had a significant effect on the area specific resistance of the composite cathodes. The area specific resistance (ASR) decreased with the increase of Ba2+ substitution. This result suggested that the electrochemical performance of Sm0.5Sr0.5Co0.8Fe0.2O3-δ based cathode improved as Sm3+ is partially substituted by Ba2+.
Effect of Stress Concentration at Circular Hole Edge for Coating on Material Processing
Authors: Bian Bu Xi , Liu Yi Hua
Published: May 2011

Coating craft process is often used on the hole surface, thus it must affect the degree of the stress concentration near the hole edge. Airy stress function methodology is used to obtain the analytical stress solution for a plate with a small coating circular hole in the center and subjected to the uniaxial uniform tension in this paper. With the help of the finite element software MSC.Patran & Nastran, the K3alloy plate is numerically analyzed, and its coating material is a ZrO2, and with the comparison of the acquired analytical solutions, it can be found that the numerical results coincide with the analytical ones very well. The results show that coating affects greatly the stress distribution near the hole edge, and the stress concentration factor in the coating increases with the coating thickness but decreases in the plate, and it increases with the shear modular ratio of the coating to the plate but decreases in the plate. The effect of the coating on the stress distribution near the hole and the stress concentration cannot be neglected.
Electrochemical Analysis of the Fluorocarbon Anticorrosion Coating after Accelerated Weathering Environment Aging
Authors: Gao Jin , Yuan Wen Juan , Li Xiao Gang , Li Ying Chao , Zhu Wei
Published: May 2011

Fluorocarbon coating was exposed to artificial weathering environment produced by the xenon lamp/condensation weathering equipment for different time periods. The degradation process was studied by electrochemical impedance spectroscopy (EIS), Fourier Transform Infrared Spectrometry (FTIR) and optical microscope. The results show that the resistance of the coatings decrease ，while the capacitance and soakage become larger with the increase of the aging time. This demonstrates that the early aging of the coating influences its protective properties for the corrosion medium. The reason is the changes of the coating’s surface state and chemical structure accelerate the penetration of medium into the coatings, and therefore accelerate the corrosion of metal occurs under the coating.
Corrosion of P110 Steel in Solutions Containing Different Chemical Compositions
Authors: Liu Li , Ren Cheng Qiang , Gao Lei
Published: May 2011

Carbon dioxide corrosion is a very complex electrochemical process. Compositions of formation water in different gas and oil wells are various, which effects on the carbon dioxide corrosion of tubular steel. HCO3- and SO42- were studied in order to further understand their role on the corrosion process. The results show marked difference when they are the main composition while others conditions is the same. HCO3- mitigates the corrosion, because its participation in cathodic and anodic reactions accelerates passivation. However, corrosion in formation water mainly containing Na2SO4 is severe, which presents higher general corrosion rate and more dangerous localized corrosion.
Preparation of Foam Ni/Carbon Nanotubes Material for Enhanced Stationary Seal Ring
Authors: Ren Jie , Yan Shi Lin , Liu Mei
Published: May 2011

Stationary seal ring, the mainly units of mechanical seal, its anti-lacking function mostly depends on the material performances. For enhanced stationary seal ring’s thermal conductivity, self-lubrication and strength, in this paper authors prepared a kind of composite material with reticular formation that is foam Ni-carbon nano tubes (Foam Ni/CNTs) as the reinforced element for stationary seal ring’s resin matrix. The experiments using Fe-Co/CNTs as catalyst via chemical vapor deposition (CVD) method prepared four groups samples with different decomposition temperature and tested by SEM and Raman spectra. The result shows that the temperature at 550°C, carbon nano tube obtained better crystallization effect and the reticular structure of foam Ni also integrity. The foam Ni/CNTs presented one kind of new reinforced phase for mechanical seal material design.
Controllable Growth and Gas Sensitivity Properties of Zinc Oxide Nanocrystalline by Solid-State Reaction
Authors: Shang Shi Guang , Xu Ke Wei , Zhao Ling , Chang Geng Rong
Published: May 2011

Zinc oxide (ZnO) nanocrystalline with different morphologies was successfully fabricated by solid-state reaction using aging Zn as precursor. Systematic experiments were carried out to investigate the factors that affect the morphologies of the samples. X-ray diffraction (XRD) spectrum shows that the as-prepared sample was hexagonal wurtzite structure. Scanning electron microscopy (SEM) images indicate that ZnO with different morphologies such as comb-like, tetrapod and flake structures, could be controlled by simply varying the ambient pressure, gas mixture ratio and growth temperature. The gas sensitivity properties of ZnO nanocrystalline thin films are investigated by observing the change of capacitance and conductance with a planar capacitor. It is found that the comb-like ZnO thin film sensor exhibits high sensitivity and fast response to ethanol at 150 °C.
Synthesis and Properties of Potassium-Containing Poly(Acrylic Acid Sodium-Co-Acrylamide)Fly Ash-Illite Superabsorbent Composite
Authors: Shen Shang Yue , Xia Kai Sheng , Ling Hui , Fan Li Ren
Published: May 2011

The fly ash with a loose and porous structure has definite absorbent ability, which has a good effect on soil improvement. Illite belongs to clay minerals, it has absorbent ability and higher potassium, which can improve the soil fertility. In this study, poly(acrylic acid sodium-co-acrylamide)(PAANa-AM)/fly ash-illite superabsorbent composite was firstly prepared by solution polymerization. The structures were characterized using scanning electron microscope, X-ray diffraction, and infrared spectrum. The results showed that the fly ash and illite dispersed well in the composite. The K+ in illite was replaced by Na+ in acrylic acid sodium and thus the illite structure turned into paragonite during the process of preparing composite, however, the structure of fly ash was maintained in the composite. Moreover, the hydroxide radical in illite reacted with the carbonyl group in acrylic acid during polymerization. The best absorbent capacities of the composite in distilled water, tap water and normal saline were 1695, 445 and 106 g/g, respectively, which exceeded the requirements of The National 863 Program and Ministry of Agriculture of People’s Republic of China. The potassium release was measured using atomic absorption spectrometry and the results indicated that the composite can release 12.80% of the potassium ion in fly ash and illite. The superabsorbent material has low cost and favors improvement of soil and potassium-deficiency.
Effect of Heat Flux on Combustion Performance of Glass Fiber Reinforced Epoxy Composite
Authors: Wang Mei , Hu Yun Chu , Huang Zi Zhi
Published: May 2011

Variation law of combustion performance of glass fiber reinforced epoxy composites under different heat fluxes was studied. Final result shows that the time of epoxy resin composite shortened when increased the heat flux, and the theoretical minimum ignition heat flux obtained by curve fitting of experiment data is 2.1638kW/m2; multiply heat flux increased the heat release rate and complicate the stratified combustion of materials, which making the heat release rate curves more complicated. What is more，multiply the heat flux caused incomplete combustion of materials and leaded greater smoke production rate. The residual quality decreased as increased heat flux, however when the heat flux beyond 50kW/m2, the residual quality no longer decreased, which suggested that the heat flux used to study these materials should not be more than 50kW/m2. To sum up the above combustion parameters ,we could know that the safety performance of this epoxy composite was medium level, in order to improve its security level further, smoke suppression should be handled.
Waterproof Performance of Gypsum Products
Authors: Li Jian Quan , Gong Ming Zhu , Li Guo Zhong
Published: May 2011

A novel compound gypsum waterproof agent made of emulsified stearic acid, alunite and naphthalene were studied, which could modify the waterproof performance of gypsum materials in microstructures. The experiment results showed that the water-absorption rate of gypsum materials can be reduced to 3.73% and that the compressive strength reserve rate was 84.71% after 24h. The waterproof mechanic of alunite is the hydration materials of alunite can fill the materials’ porosities, which can no longer be filled with water, so it reduces the water absorption and improves the strength; The waterproof mechanic of stearic acid emulsion is that it improves the gypsum material surface performance and makes the surface performance convent from hydrophilic performance to hydrophobic performance.
Flocculants for Produced Water from Polymer Flooding in Daqing Oilfield
Authors: Cao Xiao Chun , Chen Miao , Guo Hong Yan , Wang Jing
Published: May 2011

HPAM with MW of 3×106 was found suitable to simulate the composition of the formation water in Daqing Oilfield. PAC, CPAM and ZTP were used for treating the produced water from polymer flooding in Daqing Oilfield. The micro structures of the suspended materials in produced water were observed with particle imager and SEM. The results show that ZTP removed HPAM efficiently, and that both PAC and CPAM produced many aggregates.
Characteristics of Potentiodynamic Polarization Curves of Aluminum Electrodeposion Coating in Acidic Sulphate Solution
Authors: Ding Zhi Min , Shen Chang Bin , Guan Jun Shi , Gao Hong
Published: May 2011

The density and anodic potentiodynamic polarization (PDP) in different diluted acidic sulphate solution of the aluminum electrodeposion coating on Q235 steel substrate, obtained in the molten salt of AlCl3,NaCl and KCl and treated by diffusion treatment, have been investigated. The results indicated that with the increase of temperature of diffusion treatment, the dencity of the coatings increases first, then reduces little. At 500°C, the dencity is biggest, 2.76g/cm3, which is almost equal to that of compact pure aluminum. As-received coating displays a current oscillation behavior on the anodic potentiodynamic polarization curves in different diluted acidic sulphate solution . And with the increase of diffusion temperature, the current oscillation behaviors donated by the current oscillation domains in solution of 180g/L H2SO4 gradually disappeared. When the temperature is up to 500°C and 700°C, no current oscillation phenomena can be observed. Based on these phenomena, a mode between the porosity of the coating, which was affected by the temperature of diffusion treatment, and current oscillation behaviors was roughly established.
Theoretical Decomposition Voltage for Related Substance on Molten Salt Electrolysis Method to Remove Steel Surfaces of Sulfide Inclusions
Authors: Xu Ying , Gao Hua , Zhu Li Guang
Published: May 2011

The theoretical decomposition voltage (EMF) for substances in FeS-CaCl2-NaCl-KCl system was figured out. The results indicate that the EMF increases in sequence of FeS, CaCl2, NaCl and KCl with inert anodes, and it drops with rising of temperature, increases with decreasing of FeS concentration. Under a lower FeS concentration, as a result, the anode effect can occur. Fe would be separated out from cathode and Cl2 would be separated out from anode first in electrolytic desulfurization process.
The Effect of Discharge Parameters on the Plasma Electrolytic Oxidation Film’s Morphology
Authors: Wang Li , Fu Wen , Chen Li
Published: May 2011

The effect of discharge parameters (the electrode distance, the electrolyte volume) of the plasma electrolytic oxidation on the magnesium alloy films’ surface morphology were investigated. The results show that the appropriate electrode distance is 30 mm, which exhibits a better PEO surface morphologies. The electrolyte volume should not be too large or too small, in the paper, the appropriate electrolyte volume is between 250-350 mL.
Maybe Absolutely Green - with Chinese Traditional Medicine as Wood Preservative
Authors: Wang Ya Mei , Wang Xi Ming , Li Xue Qi
Published: May 2011

An important way of conservation and protection of forest resources is wood preservative treatment. Currently, chemical preservatives are always used in the wood preservative treatment. Therefore, preservatives security has become an important environmental issue. This study focuses on national wood preservation, which workers are committed on. Many studies have been directed to look for new preservatives that are harmless to humans, animals and environment. Chinese herbal medicine as a wood preservative is selected for the environmental pollution problems of inorganic preservatives. In this paper, according to the application of traditional Chinese medicine, the nature of wood preservative and a preliminary study by the relevant trial, the theory of Chinese herbal medicine wood preservative is proposed. The results showed that Chinese herbal medicine can be used as wood preservatives. Finally, the paper puts forward the potential abilities of Chinese herbal medicine as wood preservatives.
Study on Urea-Sensitive Electrode Based Porous Silicon
Authors: Li Huai Xiang , Wang Qing Yuan , Wei Qing Qing , Chen Lu Sheng
Published: May 2011

In this work, a unique electrode based on aminopropyl-triethoxysilane ( APTS)-coated porous silicon(PS) substrate has been fabricared and used as a urea-sensitive electrode after urease immobilization. PS substrate was formed by electrochemical anodization in an etching solution composed of HF and ethanol. APTS layer was formed on the PS surface by coating and heating at 1053K in argon atmosphere. Urease immobilization was carried out by immersing the APTS/PS in urease solution. The immobilized system gives linear response for concentrations of urea ranging in values between 3.6×10−3 and 8.0×10−3 mol dm-3, studied with voltammetry. The surface of biofunctionized porous silicon has thus provided a suitable environment for urease with 15 days retention of its activity. The molecular structure on the PS surface was characterized with infrared (IR) technique. The change in the surface morphology has been studied by scanning electron microscopy and it is observed that the immobilized system has successfully retained urease.
Manufacturing of Micro Drill with Electrochemical Etching
Authors: Weng Feng Tsai , Hsu Fang Chang , Hsu Kuei Shu , Ho Chi Ting
Published: May 2011

In this paper, a practical micromachining technology was applied for the fabrication of a micro drill using electrochemical etching process. Sodium chloride solution was used as electrolyte, a tungsten carbide rods can be dissolved to some micrometers from original dimension by electrochemical etching with supersonic agitation. High-aspect-ratio of micro tungsten carbide rod was easily obtained by this process. Processing performance was investigated according to applied voltage, etching time, and electrolyte concentration. A micro drill of diameter 60 μm was processed by proposed supersonic aided electrochemical etching process.
Mechanism and Protection of Stress Corrosion of Chemical Equipment
Authors: Lin Qi , Hong Zhao
Published: May 2011

The cracking mechanism of pressure vessel because of stress corrosion is analyzed, which under the high temperature and high pressure aqueous solution medium with chloride, sulfide, hot concentrated caustic, and the protection methods for corrosion under different situation are described.
Phase Selection in Undercooled Cu85Cr15 Composites
Authors: Zhou Zhi Ming , Tang Li Wen , Huang Wei Jiu , Zhou Tao , Li Xiao Ping , Luo Jing , Peng Cheng Yun , Zhan Jie
Published: May 2011

Phase selection of undercooled Cu85Cr15 composites was analyzed by using different solidification conditions. The results revealed that the arc melted composites generally have non-uniform Cr-rich dendrites distributes on Cu-rich matrix. Due to strong electromagnetic stirring, uniform Cr-rich dendrites distributes on Cu-rich matrix for electromagnetic levitation melted composites. Both fine Cr-rich dendrites and Cr-rich particles coexisted in Cu-rich matrix for splat quenched composites, which means liquid phase separation occurred for the high cooling rate.
Preparation of Mesoporous Spherical Activated Carbons with Large Specific Surface Area from Ion-Exchange Resin Having Various Metals
Authors: Zhu Zhao Lian , Li Ai Min , Yan Lei , Wu Chun Jin , Wang Hai Ling , Xu Yan Yua
Published: May 2011

Activated carbons with good spherical shape were prepared from polystyrene-derived ion exchange resin D001 having various divalent cations of Mg2+, Mn2+, and Fe2+ by CO2 activation at 800 °C for 1.0 h. The resins having univalent cation such as Na+ became fragmentized after activation, which can be attributed to their poorer thermostability than that having divalent cation. The resultant spherical activated carbon SACMg has the largest specific surface area (SBET) of 1025 m2 g-1, total pore volume (Vt)of 0.781 cm3 g-1 and mesopore volume (Vme)of 0.510 cm3 g-1. SACMg, SACMn, and SACFe all have high mesopore fraction of 65.3%, 61.0, and 59.8%, respectively.
Surface Modification of the UHMW-PE Film Processing by Hot Compression Molding
Authors: Wen Shao Guo , Shen Yan , Wang Ji Hu , Liu Hing Bo , Xu Qian , Song Shi Gao
Published: May 2011

The properties of UHMW-PE film produced by hot compression molding and films modified by acid and anti-static agent were characterized. The results showed that: a) the thickness distributing of the film which processing by calendar rolling with conventional design roller is inhomogeneity; the tensile strength was 37.22 MPa, the elongation at break was 368.00%; the transmittance increases with wavelength redshift shows short-wave absorption and long-wave transmission; initial temperature of dissociation is 320°C; the surface resistance 1010 Ω and maximum is higher than 1016 Ω. b) Acid modification the surface of UHMW-PE film moderates the surface antistatic performance. C) After modified the film with external anti-static agent, the surface resistance was around 107Ω, but anti-static properties loss rapidly after friction. If modified the film with internal anti-static agent, the surface resistance was around 1010 Ω and have a long-lasting anti-static effect.
Effect of Charging Energy on Deposited Energy of Molybdenum Wires and Coating Properties by Wire Explosion Spraying
Authors: Li Qing , Song Qiu Zhi , Wang Jian Zhong , Duo Ying Xian
Published: May 2011

With different charging energies, the wire voltages and currents were measured when the molybdenum wire explosions occurred and the coatings were sprayed on the aluminum alloy substrates. The measured voltages and currents were brought into calculating the deposited energies of the molybdenum wires. And the coatings were characterized by observing their cross sections with a Scanning Electron Microscope and testing their thickness, surface roughness and hardness. The results revealed that when the charging energy was higher, the growth rate and value of the deposited energy would be larger, the coating became denser and smoother, and the average thickness and the surface roughness were smaller, while the average hardness firstly increased, and then decreased with the ascension of the charging energy.
Study on CO2 Laser Surface Hardening of 17-4PH Stainless Steel
Authors: Zhang Jun Wei , Lei Gang , Pan Shu Chen , Wu Fa Yu
Published: May 2011

At present work, the microstructure and corresponding hardness of 17-4PH stainless steel were investigated by the process of CO2 laser surface quenching and aging treatment. The hardness of the phase transformation zone in the hardened layer was 433.2HV, higher than 378.1HV of the matrix, which was attributed to the fine-grain and solution strengthening after laser quenching. The hardness of the phase transformation zone increased further to 464.5HV after an aging treatment at 520°C due to the precipitation strengthening of fine secondary phase particles.
Synthesis and Desulfurization Performance of Flower-Like ZnO Materials by Hydrothermal Homogeneous Precipitation Method
Authors: Zhang Jing Cheng , Nan Jun , Yu Hai Bin , Liu Yun Qi , Geng Shan , Liu Hong Guang , Liu Chen Guang
Published: May 2011

To better understand the nature of reactive adsorption of thiophene on Ni/ZnO adsorbent, the effects of ZnO textural structure on the desulfurization activity were investigated. Flower-like ZnO materials were synthesized by hydrothermal homogeneous precipitation method and the corresponding Ni/ZnO adsorbents were prepared by incipient impregnation method. The analysis results showed that both the crystalline sizes and the BET surface areas of flower-like ZnO were better than that of commercial ZnO. The activity evaluations indicated that the Ni/ZnO adsorbents prepared with ZnO possessing a favorable textural structure exhibited good activity of removing thiophene. The evolutions of the main crystalline phases of Ni/ZnO adsorbents before and after reaction confirmed that ZnO played a crucial role in taking up S element and converted it into ZnS in the reactive adsorption process. It was concluded that ZnO with larger surface area and smaller crystal particles resulted in better desulfurization activity, which may be the main reason for the better activities of the Ni/ZnO adsorbents prepared with flower-like ZnO matterials.
Effect of Processing on the Dispersion of CNTs in Al-Nanocomposites
Authors: Nouari Saheb
Published: May 2011

Agglomeration and poor distribution/dispersion of carbon nanotubes (CNTs) within the matrix remains a major problem in processing homogeneous CNT reinforced metal matrix nanocomposites. In this work, we examine the effect of processing on the dispersion of CNTs in Al6061 and Al2124 alloy based Nanocomposites. Three methods were used to prepare the nanocomposite powders. In the first, CNTs were mixed with the prealloyed powder through dry ball milling. In the second, CNTs were sonicated then the prealloyed powder was added followed by sonication of the mixture and wet milling. In the third, the CNTs were functionalized, sonicated, and then the prealloyed powder was added followed by sonication of the mixture and wet milling. The effect of functionaliztion, sonication and type of milling on the dispersion of CNTs was evaluated.
Spatial Virtual Polarization Filter Design for Radar Sensor
Authors: Dai Huan Yao , Wang Xue Song , Li Yong Zhen
Published: May 2011

As interferences are introduced from main-lobe direction which results in tar-get signal are masked by interference, traditional adaptive beam-forming can not suppress main-lobe interferences effectively. Polarization filtering is a main method to suppress the interference in radar and other sensor systems. Based on the spatial polarization characteristic (SPC) of antenna, a spatial virtual polarization filter (SVPF) is proposed by constructing polarization decomposition and polarization estimation of the received signal. A generalized construction method of SVPF is provided, the performance of the SVPF is given, and simulation results of the interference suppressing are illustrated. It is indicated that the proposed filter is a valid filtering technique for interference canceling. SVPF made single polarized radar own polarization information processing ability which improved radar working performance.
Effect of V2O5 and ZnO Additives on the Sintering Temperature and Microwave Dielectric Properties of Ca[(Li1/3Nb2/3) 0.8Ti 0.2]O3-δ Ceramics
Authors: Liao Ji Hong , Dai Ying , Yang Ren Zhou , Chen Wen
Published: May 2011

Low-temperature sintered Ca[(Li1/3Nb2/3)0.8Ti0.2]O3-δ (CLNT) microwave dielectric ceramics with V2O5 and ZnO additives were prepared by the conventional solid state reaction method. The sintering behavior and microwave dielectric properties of CLNT ceramics were investigated. The main diffraction peaks of all the specimens sintered at the temperature under 1150◦C split due to the coexistence of the non-stoichiometric phase and stoichiometric phase, which all possess CaTiO3-type perovskite structures. ZnO and V2O5 combined additives lowered the sintering temperature of CLNT ceramics from 1150◦C to 1090◦C. and the Qf values were improved from 18,210 GHz to 20,740 GHz. The CLNT ceramics with 4 wt% ZnO addition sintered at 1090◦C showed good microwave dielectric properties with εr ~39.7, Qf ~20,740 GHz, τf ~8.6 ppm/◦C. The relationship between dielectric properties and the sintering behavior was also discussed.