bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Investigation on Thermal Physical Properties of an Advanced Ferromagnetic Base Composite Material
Authors: Gao Guang Fa , Yuan Shu Jie , Li Yong Chi , Duan Shi Wei
Published: June 2012

Ferromagnetic base composite materials were applied widely in aircraft and space vehicles engineering. Aimed to an advanced ferromagnetic base composite material, a series of experiments for thermal physical properties of this material were conducted, and the corresponding performance curves were obtained through statistic analyzing. The experimental results showed good consistency. And then the thermal physical parameters such as thermal expansion coefficient, engineering specific heat and sublimation heat were solved and calculated. This investigation provides an important foundation for the further research on the heat resistance and thermodynamic performance of this material.
Research Progress in Solvothermal Synthesis of Nano Functional Materials
Authors: Wang Guang Yin
Published: June 2012

In this paper, the characteristics, potential applications and preparation methods of functional nano materials were briefly introduced, and in particularly, the virtue of solvothermal reactions, as well as the solvents, were introduced
The Dyeing Research of Wool Fibers Based on Reactive Disperse Dyes in Supercritical Carbon Dioxide
Authors: Huang Yuan Li , Zheng Lai Jiu , Du Bing , Zhao Yu Ping , Song Ruo Yuan
Published: June 2012

This paper adopts reactive disperse bright-red KR-2B to dye wool skeins in supercritical CO2 dyeing equipment. The influencing factors are analyzed by measuring the surface depth of dyed wool skeins, including time, temperature and pressure, and the optimal dyeing parameters are as following: time 60min, temperature 120°C, pressure 24 MPa. Then we adopt the scanning electron microscope (SEM) and the infrared spectrum (FTIR) to observe the apparent shape and structure before dyeing and after dyeing. The results indicate that the global dye structure divide and the dyestuffs have good fixation on the wool skeins.
The Preparation of Compound Modified and Emulsified Asphalt Mortar and its Micro-Analysis
Authors: Ou Zhong Wen , Zhou Shang Yong , Zhao Zi Long , Ren Jian Min , Zhang Yi , Chen Qiao , Mo Jin Chuan , Zhao Xu Xin
Published: June 2012

The modification effects of the cement and the water-based epoxy resin on the asphalt emulsified mortar are studied. The result shows that with the cement content 30% and water-epoxy resin emulsified content 30%, the modified asphalt emulsified mortar which can replace cement mortar meets the demands of the relative criterions. When the temperature reaches 140°C, both the tensile bond strength and the shear bond strength decrease to 0.1 MPa. So it is feasible to recycle the decorative stone .The micro-analysis of the modified mortar are investigated by using IR and TGA-DTA, and its modification mechanism is also discussed.
Content Analysis of Heavy Metals in Fly Ash from One Shanghai Municipal Solid Waste Incineration (MSWI) Plant
Authors: Zhang Hai Ying , Ma Guo Xian , Yuan Guo Liang
Published: June 2012

The presence of heavy metals in municipal solid waste incineration (MSWI) fly ash is of environmental concern due to their leaching potential in landfill environments. Heavy metal content was performed on fly ash samples from a large-scale municipal solid waste incineration plant in Shanghai China. Content of heavy metals followed the decreasing sequence of Ni > Zn > Pb > Cu > Cd. As pollution of heavy metals is related to not only the content but also their leaching toxicity, further experiment of leaching concentrations of the metals is required to determine the seriousness of pollution caused by the heavy metals.
Study of In Vitro Reaction between Bone Cell and Poly(vinyl alcohol)-Matrix Composite Biomaterials
Authors: Deng Chi , Wang Bao , Zhang Cheng Dong , Zhi Wei , Weng Jie
Published: June 2012

Aim of the study is to investigate the in vitro reaction between rat bone cell and poly (vinyl alcohol) (PVA)-matrix composites. Sample of Hydroxyapatite (HA) /PVA gel composites were prepared by the in situ growth method and Experiments of Alamar Blue Activity and Alkaline Phosphatase Assay were carefully made in our lab. SEM results displays that PVA-matrix composites containing HA fillers and pure PVA as a control group have an excellent biocompatible bone reaction in vitro with rat bone cells and HA filler particles in composites promote reaction between bone cell and composites. In vitro biology experiment resulted proves that adhesion, growth and differentiation of bone cells on all PVA-matrix composites are promoted by HA filler particles.
Microstructure and Mechanical Properties of Cr1-xAlxN Coating
Authors: Zhong C.L. , Luo L.E.
Published: June 2012

A series of Cr1-xAlxN coatings were deposited by reactive magnetron sputtering. The content, microstructure and the hardness of the thin films were characterized respectively with energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and nanoindentor. The effect of Al content on the microstructure and hardness was studied. It was found that Cr1-xAlxN compound coating exhibits a cubic structure with (1 1 1) preferred orientations and that the lattice parameter of Cr1-xAlxN coatings decrease with the increase of Al content. The hardness of Cr1-xAlxN compound coating is higher than that of CrN and increases with the increase of Al content.
Catalytic Application of H3PW6Mo6O40/SiO2 in Synthesis of Acetals and Ketals
Authors: Huang Yong Kui , Yu Li , Duan Guo Bin , Wang Yun Zhi , Xu Ming Bo , Yang Shui Jin
Published: June 2012

A novel catalyst, H3PW6Mo6O40/SiO2was prepared by a sol-gel technique and its catalytic application in synthesis of acetals and ketals were tested. The preparation conditions of catalyst were optimised by using the orthogonal experimental design. The optimum conditions are: the mass ratio of H3PW6Mo6O40 to SiO2is 0.4, calcination temperature is 150 °C and calcination time is 3 h. The steric properties of the reactants play an important role in the acetalization. The catalytic activity of the catalyst decreases when the size of the reactant increased. Although a decrease in catalytic activity was observed with its subsequent reuse, the catalyst could be reused at least four times without any other treatments. The results reveal that the H3PW6Mo6O40/SiO2catalysis generally results in good yields of acetals and ketals under mild reaction conditions.
Dyeing Properties of Cyanoethylated Wood with Disperse Dyes
Authors: Wan Xiao Qiao , Zhao Fang , Yu Ze Hua , Zhao Ying
Published: June 2012

The color cyanoethylated wood were preparated by means of dyeing under high temperature and pressure. The results indicates that the percentage of dye exhaustion (%E) on cyanoethylated fir powder is 95.3~98.8%. The color shade of dyed modified wood is similar to that of dyed polyester fabric. Compared with the dyed polyester fabric, the color difference (∆E) of dyed modified wood is smaller than that of dyed unmodified wood under the same dyeing condition. Unmodified fir powder, cyanoethylated fir powder and dyed cyanoethylated fir powder were characterized by Fouriertrans- form infrared (FT-IR), scanning electron microscopy (SEM).
Numerical Analysis on Consolidation Settlement of Soft Soil Foundation for Artificial Island
Authors: Tang Xiao Wei , Ma Zhe Chao , Li Zhen Qing
Published: June 2012

With the fast development of technology and growth of population, humans began large-scale construction for artificial island. In the field of artificial island research, settlement calculation is pay great attention. According to the geological data surveyed from one artificial island in northern china, using layer-wise summation method and finite element method which based on effective stress theory and Darcy law, the final settlement of the island is calculated. In the meantime, the result of two methods is comparatively analysis.
A Measuring System of Water Eutrophication Based on the Algae Characteristic Changes
Authors: Zhao Xiao Qiang , Zhang Ying , Li Si Jie , Wang Han Lu
Published: June 2012

With the algae play an important role in water eutrophication, a set of measuring system of water eutrophication based on the algae characteristic changes is designed, according to the relationship between the eutrophication and the algae characteristic changes. It is according to Canny self-adaptive edge detection algorithm, K-nearest neighbor classification algorithm, image processing technology, and the algae species and area’s changing, determined the status and level of water eutrophication pollution. The experiment result shows that the algae characteristic changes are realized and the water eutrophication is measured by the system. What’s more, the system has many advantages like adaptive, self-judgment and even good application value.
Kinetics on the Leaching of Polysaccharide from Arctium lappal Root
Authors: Li Jin , Pang Jing Hua , Deng Cong , Zhao Peng , Hou Shu Zhen
Published: June 2012

To explore the kinetics parameters in the leaching of polysaccharide from Arctium lappal root. According to Fick’s second law of diffusion, the kinetic equation for polysaccharide leaching process was established with ball model. According to Fick’s second law of diffusion, leaching process was analysed. The results can provide the valuable theory basis for the technical design and further research of polysaccharide leaching process.
Synthesis of Ni@MWCNTs Magnetic Nanocatalysts and their Catalytic Activity towards 4-Nitrophenol Reduction
Authors: Zhang Ming Mei , Sun Qian , Xie Ji Min
Published: June 2012

A well-dispersed Ni nanoparticles on multi-walled carbon nanotubes (Ni@MWCNTs) was prepared by chemical vapor deposition (CVD) method using a vacuum quartz tube furnace at the temperature of 600°C. The scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) were performed to characterize the synthesized catalyst. It shows an unfirom dispersion of Ni nanoparticles on MWCNTs with the average particle size of 8.6 nm. The as synthesized catalyst was applied in a redox reaction of 4-nitrophenol, which showed very high catalytic activity, stability and well conversion. The catalyst can be easily separated due to the magnetical performance
Adsorption of Phenol onto Activated Carbons
Authors: Tan Xiao Yan , Li Guo Lan , Li Song
Published: June 2012

Coal-based Activated carbon was modified by thermal and nitric acid treatment to adsorb phenol from aqueous solution. Boehm titration, point of zero charge ( pHPZC ) and X-photoelectron spectroscopy (XPS) were used to characterize activated carbons. Acid treatment leads to the increase of the content of surface oxygen, whereas thermal treatment causes the decrease of the content of surface oxygen.The surface characteristics of activated carbons have significant effect on phenol adsorption. The adsorption isotherms of phenol adsorption are described by Langmuir isotherm. The kinetic studies indicate that the adsorption process is fitted well by the pseudo-second- order kinetics.
Migration Behavior Research of Residual Acrylonitrile Monomer in ABS Tableware
Authors: Lin Zhi Dan , Guan Zi Xian , Li Quan Zhong , Wang Wei Wei , Li Bo Ping , Li Zheng Jun
Published: June 2012

In this paper ABS parts plus acrylonitrile monomer were prepared using melt blending method by twin-screw extruder, and the influence of soaking temperature, concentration of acrylonitrile monomer, ABS copolymer composition on the short-term migration of residual acrylonitrile monomer into pure water was studied, and the long-term migration behavior and diffusion coefficient were also further characterized.
Influences of Coagulation Bath on Properties of Thermal Regulating PAN Fibers
Authors: Li Zhen Zhong , Wei Ju , Zheng Lai Jiu , Du Bing , Zhao Yu Ping
Published: June 2012

Physical properties of thermal regulating polyacrylonitrile (PAN) fibers prepared at different concentration of coagulation bath were tested to investigate influences of coagulation bath on properties of the fibers. Results indicated that linear density of the fibers increased, breaking strength, thermal shrinkage and boil water shrinkage decreased while elongation first increased and then decreased with the increasing of mass fraction of sodium thiocyanate (NaSCN) in coagulation bath. The optimum NaSCN concentration in coagulation bath should be 10%. Fibers prepared under the above NaSCN concentration showed good mechanical and thermal properties, and the breaking strength was 1.35 cN/dtex, the enthalpy was 26.0 J/g and the thermal efficiency was 78.4%.
Synthesis, Characterization and Photophysical Properties of Rhenium Complex-Containing Polymer PS-b-PMAA(PNPh-Re)
Authors: Liu Wen Qu , Xia Hong Ying , Zhao Feng
Published: June 2012

Two blcok copolymer PSt-b-PtBMA were synthesized by using ATRP method, in acid conditions, and further hydrolysis into amphiphilic copolymers PSt-b-PMAA; the PS-b-PMAA containing transition metal complex was obtained through PNPh-Re covacent-link to PS-b-PMAA chains, and the corresponding copolymers were charcterized by UV-vis and 1 H NMR.
Effect of Rare Earth on the Inclusions and Pitting Resistance of Ferrite Stainless Steel
Authors: Liu Xiao , Li Jian She
Published: June 2012

The anodic polarization curves of 430 ferrite stainless steels with various RE contents in 3.5% NaCl neutral solutions have been measured by electrochemical methods. The effect of RE on pitting corrosion resistance of 430 ferrite stainless steels has been studied by the metallographic examination. The results show that sulfide and other irregular inclusions are modified to round or oval-shaped RE2O2S and RES after adding RE to 430 ferrite stainless steesl. RE makes sulfide, and other irregular inclusions change to dispersed round or oval-shaped RE inclusions, effectively inhibits the occurrence of pitting corrosion, thereby enhancing the corrosion resistance of 430 ferrite stainless steels.
Synthesis of the Thermoelectric Thin Films of Ca3Co4O9 and Ca3Co2O6 Using Pulsed-Laser Deposition Techniques
Authors: Li Zhi Dong , Wu Dong , Zhao Kun Yu , Zhang Hui
Published: June 2012

Thermoelectric ceramic targets of Ca3Co4O9and Ca3Co2O6were prepared by the sol-gel method. The technology and mechanism of synthesizing the thermoelectric thin films of Ca3Co4O9and Ca3Co2O6were investigated. The thin films of Ca3Co4O9and Ca3Co2O6were grown on (0001)-oriented (c-cut) Al2O3substrates by pulsed-laser deposition techniques (PLD). Ca3Co4O9thin films grown at substrate temperature of 700°C and 800 °C appear to be obviously c-axis-oriented. But the x-ray diffraction peak of Ca3Co2O6thin films was not confirmed. Ca3Co4O9thin films and Ca3Co2O6thin films exhibited Ca elements and Co elements volatilization at high temperatures.
The Application of Organic (PVDF) Tubular Membrane on the Treatment of Catering Sewage
Authors: Han Shao Xun , Wu Yun , Zhang Hong Wei
Published: June 2012

Domestic organic tubular membrane was used uncommonly in treating catering sewage. The material of PVDF (polyvinylidene fluoride) shows excellent performance in my research. And it also showed great antipollution capacity to oil and grease when COD, TN, SS, OIL, LAS of the effluent accorded with “Synthetically Draining Standard of Sewage”, GB8978~1996.
Preparation of SiO2 Aerogel Supported Nano-TiO2 Photocatalysts for Removing Rhodamine B in the Waste Water
Authors: Shi Fei , Liu Jing Xiao , Tang Nai Ling , Dong Xiao Li , Zhang Xin Xin , Bai Lu Nan , Leng Xiao Wei
Published: June 2012

Using the as-prepared SiO2 aerogels as carriers, SiO2 aerogel supported nano-TiO2 (TiO2/SiO2 aerogel) photocatalysts were prepared by sol-gel and adsorption loading process. The microstructure, morphology and properties of the obtained TiO2/SiO2 aerogel were studied by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and Brunauer-Emmett-Teller (BET) N2 adsorption-desorption analysis. The adsorption/photocatalytic degradation for Rhodamine B of TiO2/SiO2 aerogel composite photocatalysts was investigated. The results indicate that TiO2 sol concentration is the main factor influencing the microstructure and properties of TiO2/SiO2 aerogel composite photocatalysts. With the increasing of TiO2 sol concentration, the amount of loaded TiO2 increased, but the specific surface area, pore volume and pore size gradually decreased. The specific surface area, pore volume and pore diameter of TiO2/SiO2 aerogel photocatalysts after annealed at 550oC are 444.76～750.34 m2/g, 0.08～0.70 m3/g and 2.46～4.58nm, respectively. The TiO2/SiO2 aerogel prepared with 0.75 mol/L TiO2 sol concentration has best adsorption/photocatalytic degradation for Rhdamine B.
Study of Initial Corrosion Behaviors of Pure Copper under Simulated Marine Atmosphere
Authors: Xin Jing Ping , Chen Zhuo Yuan , Hou Bao Rong
Published: June 2012

The corrosion behaviors of pure copper were studied in initial exposure to a simulated marine atmosphere. A two-electrode cell system with two identical pure copper plates had been employed in electrochemical tests of potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The copper electrodes were deposited with 70 µg cm-2 NaCl particles and then exposed in a humidified pure air of 97% RH at 25 °C. The time-evolution of corrosion current density obtained from the cathodic polarization curves had a trend of firstly decreasing, then increasing and finally getting a relative stable stage. The EIS data showed that the transition of two time constants corrosion stage to three time constants corrosion stage. The initial atmospheric corrosion behaviors of pure copper could be divided into three stages, including rapid corrosion stage, diminished corrosion stage and balanced corrosion stage.
Research of the Image-Based Automatic Identification of the High-Strength Al-Alloy Grain Size
Authors: Zhang Li Xin , Wei Shuai Ling , Xu Zheng Guang , Ren Xue Chong , Lin Li Li , Li Heng Kui
Published: June 2012

In the quantitative analysis of metallographic organization, the grain size is a fundamental parameter. The traditional methods of getting the grain size depend on artificiality. These means have strong subjectivity and low efficiency. In this paper, a new digital image processing technology method is proposed for the measurement of the grain size. The experiment with the 7050 Al-alloy samples show that the proposed algorithm has performed well compared with the artificial methods.
Methods of Support Vector Machine on Classification of Expansive Soils
Authors: Yang Hai Ying , Liu Yun
Published: June 2012

The classification of the grade of shrink and expansion for the expansive soils was the initial and essential work for engineering construction in expansive soil area. Based on the principle of support vector machine analysis, a classification model of expansive was established in this paper, including five indexes reflecting the shrink and expansion of expansive soil, liquid limit, swell-shrink total ratio, plasticity index, water contents and free expansive ratio and functions were obtained through training a large set of expansive samples. It was shown that the classification model of SVM analysis is an effective method performed excellently with high prediction accuracy and could be used in practical engineering.
The Impact of Seawater Corrosion on Friction Force of Cylindrical Deputy Campaign Latch
Authors: Zhao Cheng , Luo Kun
Published: June 2012

According to the stress state and importance of cylindrical deputy campaign latch, NO. 2 cylindrical deputy campaign latch was selected as research subject. The work including design , processing, finite element load calculation, friction force before and after corrosion of similarity samples were carried out according to similarity theory. Friction force calculations of cylindrical deputy campaign latch before and after corrosion were 1206N and 1222N respectively. Compared with the friction force before corrosion, the friction force of cylindrical deputy campaign latch was increased by 19.1% because of seawater corrosion.
Study on the Stress-Induced Crystallization and the Constitutive Equation of Ethylene-Propylene Diene
Authors: Wang Hong Bao , Song Meng , Tan Jin Mei , Wu Si Zhu
Published: June 2012

The composition and sequence structure of a serial of ethylene-propylene diene (EPDM) were analyzed according to the 13C-NMR analysis. The stress-induced crystallization was occurred in EPDM 3080 which the segment chains of methylene were long enough. The mechanical properties of stress-induced crystallization of EPDM 3080 were increased rapidly when the extension ratio reached about 4.5. With the observation by the synchrotron two-dimensional wide angle X-ray diffraction, it confirmed that the increasing stress just begin at the extension ratio of 4.5, which can be attributed to the stress-induced crystallization. Based on the rubberlike network model with crosslinking, entanglement and stress-induced crystallization interaction points, the constitutive equation can be derived according to rubber statistical distribution function and the free energies of deformation. The modified constitutive equation was compared with the stress-strain experimental data. It showed that the deduced stress-induced crystallization constitutive equation of EPDM rubber was in good agreement with the experimental results, which offered a theoretical base for the prediction of the stress-induced crystallization rubber materials.
Research on the Strength and Permeability of Fly Ash Concrete Mixing Fiber
Authors: Liu Dong Mei
Published: June 2012

The effect of polypropylene fiber and steel fiber on workability, strength and permeability of fly ash concrete was studied. Admixing polypropylene fiber or steel fiber in concrete, the workability of fresh concrete became worse. To Keep the same slump and well cohesiveness, mixing polypropylene fiber in concrete could not improve the early strength of concrete, steel fiber used in concrete can improve especially flexure strength obviously. The wear resistance of concrete with polypropylene fiber or steel fiber all increased, the permeability resistance was not decreased, impervious grade is still greater than W8.
The Synthesis of a Novel Plasticizer and its Application in Polymer Electrolytes
Authors: Gu Ning Yu , Ao He , Li Chao , Xie Yuan Yuan
Published: June 2012

Novel four-arm star-shaped (STEO) plasticizer was synthesized and characterized by FT-IR and NMR methods. The mixtures of STEO and ethylene carbonate (EC) were used as plasticizers in polyethylene oxide (PEO)-based polymer electrolytes. The effects of plasticizers on the thermal properties and the ionic conductivities of polymer electrolytes were reported. Results showed that the addition of plasticizers could effectively decrease the melting temperatures and the degree of crystallization of polymer electrolytes, and the ionic conductivities increased with the addition of plasticizers. When the mass ratio of STEO and EC was 1:1, mixed plasticizer had the best plastifying effect on the gel polymer electrolytes.
Transparent Oxyfluoride Glass-Ceramics Containing CaF2 Nano-Crystalline Phase
Authors: Hou Zhao Xia , Xue Zhao Lu , Wang Shao Hong , Hu Xiao Dan , Lu Hao Ran , Niu Chang Lei , Wang Hao , Wang Cai , Zhou Yin
Published: June 2012

Transparent oxyfluoride tellurite glass with the composition of TeO2-SiO2-AlF3-CaO-KF system were prepared by conventional melting and annealing technique, and the transparent oxyfluoride glass-ceramics containing CaF2 nano-crystallines were obtained by controlled heat-treatment. The effect of heat-treatment schedules on the crystallization behavior and the microstructure of the glass-ceramics were analyzed by differential scanning caborimetry (DSC) analysis, X-ray diffraction (XRD) analysis, infrared (IR) spectrum and scanning electron microscopy (SEM). The sole CaF2 crystalline phase was confirmed by XRD, the spherical CaF2 nano-crystallines at about 20~100nm embed homogeneously among the glassy matrix after crystallization by SEM observation. The size of CaF2 grains grew with the increase of crystallization temperature and holding time. Te and Si atoms existed in [TeO3] and [SiO4] forms. Part of Al atoms existed in the form of [AlO4] and formed network together with [SiO4] tetrahedron. The other Al atoms acted as modifiers in the form of [AlO6]. The transmittance of glass-ceramics can reach 85% in visible light and 90% in infrared waveband. The novel transparent oxyfluoride tellurite glass-ceramics are excellent matrix materials in up-conversion luminescence field.
Preparation and Investigation of High Emissivity Coatings Prepared by Plasma Spraying
Authors: Wang Can , Wang Quan Sheng , Sun Xian Kai
Published: June 2012

The high emissivity coating was deposited by Air Plasma Spraying (APS). Ni2O3, Cr2O3 were the main raw materials in this study. The feedstock powder was prepared by spray drying and post-sintering at 1420 °C for 2hours. The microstructure, phase structure, flowability and bulk density of the plasma sprayed powder were characterized. The microstructure, bond strength and infrared emissivity of the high emissivity coating were also analyzed in this paper. The results reveal that the powder before and after sintering presents good flowability and is suitable for plasma spraying process. A dense coating with the bond strength of 28.14MPa was prepared successfully. The normal emissivity of the coating in all waveband is 0.87 at the temperature of 300°C, 600°C, 900°C, 1000°C, 1100°C and 1200°C
Silica Coatings Pigmented with Core-Shell Particles for High-Temperature Radiation Heat Shields
Authors: Wang Guang Hai , Zhang Yue , Chen Yu Feng
Published: June 2012

Hollow glass micro-beads uniformly coated by a shell of titania with thickness of 50 to 300 nm, were fabricated by wet chemical methods. The pigments were dispersed in silica coatings，then the pigmented coatings were deposited on quartz substrates by sol-gel spin-coating method with a thickness of about 80 µm. SEM, TEM and FT-IR techniques were used to characterize the microstructure and properties of the coatings. FT-IR indicated average infrared transmittance of coatings containing the core-shell particles was significantly lower than that of coatings containing no functional particles or containing hollow glass micro-beads, when the volume fraction of core-shell particles was just 5%. In view of its low infrared transmittance, pigmented silica coatings may find applications in high-temperature heat-insulating materials for reducing radiation heat transfer.
Influences of Argon Ambience on Phase Composition and High Temperature Oxidation Resistance Property of Ceramic Coatings on Ti Alloy by Micro-Arc Oxidation
Authors: Hao Guo Dong , Yang Zhi Gang , Zheng Xu Xu , Zeng Xu Zhao , Wu Xu Yan
Published: June 2012

Abstract. Compound ceramic coatings with the main crystal phase of Al2TiO5 (as-coated samples) were prepared in situ on the surface of Ti-6Al-4V alloy by means of pulsed bi-polar micro-arc oxidation (MAO) in an NaAlO2 solution. The coated samples were calcined in argon and air at 1000 oC, respectively. The phase composition, surface and section morphology, and element contents of the ceramic coatings were investigated by X-ray diffractometry(XRD), Scanning electron microscopy (SEM) and X-ray fluorescence spectroscopy (XRF). The samples were treated in argon and the as-coated ones were calcined in air at 1000 oC to study the anti-oxidation properties of the samples. The results show that Al2TiO5 had been decomposed in an hour and transformed into α-Al2O3 and rutile TiO2 in air. However, Al2TiO5 had been decomposed in four hours in argon and the final coating surface was completely composed of α-Al2O3. The content of Al2O3 was decreased from outside to inside layers and Ti2O3 was formed in the coating. Furthermore, the morphology of the ceramic coatings after the calcination was different. The coatings calcined in argon were finer; the grains and pores were smaller than those in air. The high oxidation reaction of the TC4 substrate was the fiercest and the weight gains of the coated samples treated in argon was the lowest. The weight gains of the ceramic coatings were nearly changing in the form of parabola law.
Microwave Properties in BaO-TiO2 System Added by ZrO2 and WO3
Authors: Yang Xin Ye , Wang Xiao Hui , Ji An , Li Long Tu
Published: June 2012

Both BaTi4O9 and Ba2Ti9O20 have the best microwave properties among many compounds in BaO-TiO2 system. The microwave performance of the ceramics in BaO-TiO2 system, which were prepared by conventional solid state method, was investigated in this paper. The study indicates that the (Ti,Zr)/Ba ratio has a great effect on the dielectric properties of the ceramic due to different BaTi4O9/Ba2Ti9O20 ratio. The pure BaTi4O9 ceramic exhibits the most outstanding microwave properties, with εr=35.55 and Q×f=43300GHz. On the contrary, the dielectric property of the pure Ba2Ti9O20 ceramic was not good enough, which should be doped with some additive additions. WO3 was incorporated into the system and the sintering temperature was adjusted to improve the microwave dielectric property. The Q×f was increased to 38000GHz by adding 1.35mol% WO3 due to the formation of a little BaWO4 phase. When sintered at a higher temperature (1380°C), the BaO-TiO2 system ceramic has εr =37.04 and Q×f =44874GHz.
Synthesis and Characterization of BaTiO3-(Bi0.5Na0.5)TiO3 Solid Solution Based Dielectric Ceramics
Authors: Yao Guo Feng , Wang Xiao Hui , Li Long Tu
Published: June 2012

BaTiO3-(Bi0.5Na0.5)TiO3 (BTBNT) solid solution ceramics with the Curie temperature higher than 150°C were prepared, which were promising for X9R MLCCs application. (Bi0.5Na0.5)TiO3 (BNT) was first synthesized by the conventional solid state reaction and then it was mixed with BaTiO3 (BT) with increasing BNT content from 0 to 12 mol%. BaTiO3-(Bi0.5Na0.5TiO3 solid solutions were obtained after calcining at 1100°C. The structural and dielectric properties of BTBNT and Nb-doped BTBNT ceramics were investigated.
Effect of Annealing Treatments on the Physical Characteristics of (Ca0.8Sr0.2)TiO3 Thin Films by Sol-Gel Method
Authors: Tseng Ching Fang , Lu Yun Pin , Tung Hsin Han , Yang Pai Chuan
Published: June 2012

This paper describes physical properties of (Ca0.8Sr0.2)TiO3 were deposited by sol-gel method with a fix per-heating temperature of 400oC for 60 min at various annealing temperatures from 600oC to 700oC for 60 min. Particular attention will be paid to the effects of an annealing treatment in air ambient on the physical properties. The annealed films were characterized using X-ray diffraction (XRD). The surface morphologies of annealed film were examined by atomic force microscopy and scanning electron microscopy.
Effect of Sintering Temperature on Structure and Dielectric Properties of BZN Ceramics
Authors: Xu Yun Hui , Zhu Xiao Hong , Zhang Qiang , Zhu Jian Guo , Xiao Ding Quan
Published: June 2012

Bismuth zinc niobate [(Bi1.5Zn0.5)(Nb1.5Zn0.5)O7, abbreviated as BZN] ceramics are receiving increasing attention due to their excellent dielectric properties in the microwave frequency range. This work is aimed at improving the fabrication technology of BZN ceramics. BZN ceramic specimens were prepared using the general electronic ceramic technique including milling, calcining, crushing, pressing, and sintering. Different sintering temperatures in the range of 950-1080°C were used to study how sintering temperature affects the structure and dielectric properties of BZN ceramics. The crystallinity and microstructure of the BZN ceramics, which were measured respectively by X-ray diffraction and scanning electron microscopy, were improved with increasing of the sintering temperature. The frequency dependence of the dielectric constant and loss tangent was measured at room temperature from 1 kHz to 1 MHz. The dielectric properties of the specimen sintered at 1050°C were found to be the best, for which the relative permittivity (εr) and the loss tangent (tanδ) are around 146 and 0.005, respectively. It was also foεund that when the sintering temperature was higher than 1000°C, the εrand the tanδ of BZN ceramics sintered at different temperatures were similar. As a result, 1000°C may be an appropriate sintering temperature for BZN ceramics.
Fabrication and Study of BiNbO4 Ceramics
Authors: Lisińska-Czekaj Agata , Czekaj Dionizy
Published: June 2012

Aim of the present research was to fabricate and study crystalline structure as well as dielectric properties of BiNbO4 ceramics. In the present study BiNbO4 ceramics was fabricated by solid state reaction from the mixture of simple oxides viz. Bi2O3, and Nb2O5. Stoichiometric mixture of the powders was thermally analyzed so parameters of the thermal treatment were determined. The EDS measurements proved conservation of the chemical composition of the ceramic powder after calcination (T=800°C). Free sintering at T=870 – 1080 °C was used for fabrication of the ceramic samples. Morphological analysis using scanning electron microscopy was performed. The crystalline structure of the sintered samples were examined by X-ray diffraction method at room temperature. It was found that for low temperature of sintering (T0C) bismuth niobate crystallized in orthorhombic symmetry Pnna (52) whereas for high sintering temperature (T>1000 °C) BiNbO4 exhibited anorthic symmetry P-1 (2). Low frequency (ν=100Hz – 1MHz) impedance spectroscopy was applied to study influence of the sintering temperature on dielectric properties of bismuth niobate at room temperature. The equivalent circuit method was used for analysis of the impedance data.
Phase Behaviors of Talc Minerals in Carbothermal Reduction Process
Authors: Li Wen Juan , Huang Zhao Hui , Pan Zi He , Liu Yan Gai , Fang Ming Hao
Published: June 2012

In this paper, we focus on the phase behaviors of talc minerals by carbothermal reduction (CR) method. The effects of temperature and carbon addition are both discussed in our work. In the experiment, acid-leaching talc was employed as raw material, carbon coke powders were adopted as reducing agent. The XRD results show that: When acid-leaching talc was used as raw material, quartz and few enstatite can be obtained at 1300 °C, with the temperature increasing, the diffraction intensities of enstatite increased. At 1550 °C, enstatite transformed to magnesium silicate and obvious β-SiC can be detected. At 1600 °C, the main phases in the final product are magnesium silicate and β-SiC. The SEM results reveal that the preferred, as-fabricated silicon carbide has morphology of irregular shape. Relatively pure β-SiC can be obtained by using acid-leaching talc mixed together with excess 50% of theoretical quantity of carbon powder sintered at 1550 °C for 4 h.
ZnTiO3 Doping Effect on Dielectric Properties of CCTO Ceramics via a Molten Salt Process
Authors: Yu Rong , Cao Ze Liang , Xue Hao , Xiong Zhao Xian
Published: June 2012

CaCu3Ti4O12 (CCTO) powder was prepared by solid-state reaction. CCTO-ZnTiO3 composite ceramic were prepared by reaction of CCTO powder with molten ZnCl2 in air, 400°C. The products were examined by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electric and dielectric properties of CCTO-ZnTiO3 composite ceramic were investigated. It is shown that the ceramic composites have higher grain-boundary resistivity and nonlinear coefﬁcient. The addition of Zn mainly formed in the form of ZnTiO3 also affected the low frequency capacitance values, reduced the CCTO ceramic dielectric loss, which showed a Schottky-type nature of potential barrier. Moreover, the mechanisms involved in the NBLC model were discussed, where it is working with the IBLC model.
Preparation and Dielectric Properties of Cr Doped Multiferroic BiFeO3
Authors: Qi Xi Wei , Zhang Xiao Yan , Qi Jian Quan , Xu He Ji , Wang Hai Feng
Published: June 2012

A series of Cr doped multiferroic BiFeO3 (BFO) with the composition of BiFe1-xCrxO3 have been prepared using hydrothermal method, in which x varies as 0, 0.05, 0.1, 0.2, 0.3, 0.4 and 0.5. The synthesis temperature is carried out as low as 230 °C under hydrothermal conditions. With the increase of the content of Cr, the second phase is gradually increased. When the value of Cr is 0.5, the main peak (110) and (104) of BFO tends to disappear, in which the structure of BFO is changed. The permittivity of as-prepared samples decreases with the increase of Cr content and excellent frequency stability is exhibited. Better grain structure can be obtained for samples sintered at 830 °C
Study on Electronic Properties of ZnO Doped with Cr, Mn and Co by First Principles
Authors: Gao Xing , Gan Guo You , Yan Ji Kang , Du Jing Hong , Zhang Jia Min , Yi Jian Hong , Wang Li Hui
Published: June 2012

A method using first principles and pseudopotentials based on density functional theory is applied to calculate the electronic structure and the density of states of ZnO doped with Cr, Mn and Co. Portion of Zn atoms in ZnO crystal randomly substituted by Mn, Cr or Co elements, the electronic structure of Cr2+, Mn2+and Co2+change into 3d4, 3d5and 3d7, which result in giving rise to localized magnetic moments in ZnO. It was concluded that electronic property of ZnO is not only related with levels of electrons, but also associated with spin, spin-dependent scattering and spin-dependent hopping conductivity are maybe two important mechanism.
Cryomilling and Characterization of Metal/Ceramic Powders
Authors: Hou Qing , Shi Zhi Cheng , Fan Run Hua , Ju Li Cheng
Published: June 2012

Al/Fe2O3 thermite powders were prepared by cryomilling at liquid nitrogen temperature. The cryogenic temperature will restrain the mechanochemical reaction between alumina and iron oxide, leading to high reactivitive nanoscale powders. The size distribution of the powders was analyzed using laser particle size analyzer, and cryomilling was proved to be an effective method to prepare ultrafine powders. The differential scanning calorimetry (DSC) analysis indicated that the cryomilled powders get more fully-reacted, a larger proportion of solid-solid reaction and more heat release in the solid-liquid reaction, comparing with the powders milled at room temperaure. Furthermore, the reaction kinetics of Al-Fe2O3 system is analyzed by a model-free Starink method. The activation energy for solid-solid reaction of 2Al-Fe2O3 thermite mixture cryomilled for 40 min is determined as 250 kJ/mol. The alternating gradient magnetometer (AGM) analysis shows that long time milling evoked the thermit reaction between Al and Fe2O3, leading to the increase in saturation magnetization (Ms) and remanent magnetization (Mr).
Ferroelectric and Physical Characteristic of the La and V Doped on Bi4Ti3O12 Thin Film Prepared by RF Magnetron Sputtering Method
Authors: Chen Shih Fang , Chen Kai Huang , Cheng Chien Min
Published: June 2012

In this study, the effects of La and V doping on Bi4Ti3O12(BLTV) ferroelectric thin films deposited on ITO/glass substrates using rf magnetron sputtering were produced and investigated. The effect of oxygen concentration and RF power on the physical and electrical characteristics of BLTV thin films was determined. The physical characteristics of BLTV thin films were obtained by the XRD pattern, SEM and AFM. The variations of crystallization, surface roughness and thickness of BLTV thin films were discussed. The electrical properties of BLTV thin films deposited under various parameters were measured by the HP4156C.
Electrical and Physical Properties of Lead-Free (Na0.5K0.5)NbO3- Bi0.5(Na0.93K0.07)0.5TiO3 Ceramics
Authors: Wang Chun Huy
Published: June 2012

Extending the investigations on (Na0.5K0.5)NbO3-based solid solution for lead-free piezoelectric ceramics, this paper consider the complex solid-solution system (Na0.5K0.5)NbO3–Bi0.5(Na0.93K0.07)0.5TiO3 [NKN-BNKT]. (Na0.5K0.5)NbO3 with 2 ~ 6 mol% Bi0.5(Na0.93K0.07)0.5TiO3 has been prepared following the conventional mixed oxide process. A morphotropic phase boundary (MPB) between orthorhombic (O) and rhombohedral (R) was found at the composition 0.98NKN-0.02BNKT with correspondingly enhanced dielectric and piezoelectric properties. The electromechanical coupling factor and dielectric constant are higher for compositions near the MPB. The dielectric constant (KT33), planar coupling coefficient (kp) and thickness coupling coefficient (kt)of 0.98NKN-0.02BNKT ceramics were 1040, 47% and 48%, respectively.
Phase Transitions, Dielectric and Piezoelectric Properties of BiScO3-PbTiO3 Ceramic Solid Solutions
Authors: D. Politova Ekaterina , M. Kaleva Galina , V. Mosunov Alexander , G. Segalla Andrei , Zeng Jiang Tao
Published: June 2012

Dielectric and piezoelectric properties of ceramic solid solutions based on the compositions close to the MPB in the system (1-x)BiScO3 – xPbTiO3 (x- 0.63, 0.635, 0.64) have been studied. The 1st order phase transitions were observed at temperatures near 700 K. Increase in the lead titanate content stimulates slight increase in the TC value. Cr2O3 additives in amounts up to 0.2 w. % favor to the decrease of total conductivity and dielectric loss at high temperatures. Increase in the d33 and kt piezocoefficients was observed in modifed ceramic. Besides peaks in temperature dependences of dielectric permittivity and dielectric loss marked ferroelectric to paraelectric phase transitions, effects of dielectric relaxation, determined by oxygen vacancies were revealed.
Impedance-Frequency Spectrum and Soft/Hard Doping Characteristics of Lead-Free K0.5Na0.5NbO3-LiSbO3-BiMnO3 Piezoelectric Ceramics
Authors: Jiang Min Hong , Liu Xin Yu , Chen Guo Hua , Ma Jia Feng
Published: June 2012

K0.5Na0.5NbO3-LiSbO3-BiMnO3 (KNN-LS-BM) lead-free piezoelectric ceramics were prepared by the traditional ceramic processing. The “soft” and “hard” doping characteristics of the ceramics were studied by the impedance-frequency spectrum method. Results show that the single 0.4at.% BM-doping KNN ceramics show “hard” characteristics because the top shape of profile θ-f the ceramics is almost rectangular, while the single LS-doping KNN ceramics shows “soft” characteristics because of the top shape of round. The LS and BM co-doping make KNN ceramics to show “soft” and “hard” doping characteristics at the same time. Because the soft doping of LS in KNN is more preponderant than that of BM, the co-doping KNN ceramics show “soft” doping characteristics as a whole.
Synthesis of Single-Crystalline Plate-Shaped K0.5Na0.5NbO3 Particles by Multi-Step Molten Salt Method
Authors: Liu Zhi , Li Yue Ming , Shen Zong Yang , Wang Zhu Mei
Published: June 2012

In this study, single-crystalline plate-shaped KNN particles were successfully synthesized by a multi-step molten salt method (MMSM). First, precursor particles K4Nb6O17 (K4N6) with layer-structure was synthesized at 1050 °C in molten KCl-salt (MMSM-1) by starting materials of Nb2O5 and K2CO3. Second, plate-shaped KNN was synthesized at 1000 °C in molten KCl-NaCl-salt (MMSM-2) from K4N6 particles and K2CO3 powders. X-ray diffraction (XRD) analysis revealed that the crystallographic {010} plane of K4N6 was converted into the pseudo-cubic {001} plane of KNN. SEM images showed that MMSM-synthesized KNN particles preserved the shape of K4N6 precursor particles, and had a thickness of about 3 ~ 5 μm, a width of 10 ~ 15 μm and a length of 15 ~ 20 μm. EDX spectrum proved that the K:Na mole ratio was 0.6:0.4. These plate-shaped KNN particles were very promising templates to fabricating textured KNN-based ceramics.
Doping Effect of W6+ Ions on Microstructural and Magnetic Properties of Mn-Zn Ferrites
Authors: Xing Qing Kai , Peng Zhi Jian , Wang Cheng Biao , Fu Zhi Qiang , Fu Xiu Li
Published: June 2012

Mn-Zn ferrites with different doping contents of W6+ ions were prepared by using standard ceramic technique. The microstructure and magnetic properties of the as-prepared Mn-Zn ferrites were investigated. It was found that all the samples with different contents of W6+ ions consisted of ferrite phase of typical spinel cubic structure. With increasing doping content of W6+ ions, the lattice constant of the ferrites decreased but the grain size increased. Through the measurement of magnetic properties, it was revealed that the saturation magnetization and initial permeability of the samples increased with small doping content of W6+ ions but decreased with additional doping, and the Curie temperature decreased monotonously with W6+ ion doping.
Synthesis and Characterization of Silver-Coated Copper Powder Layer
Authors: Zhu Xiao Yun , Hu Lie , Dong Man
Published: June 2012

This paper presents the process of preparing spherical silver-coated copper powder with a silver content of 30-50%, using chemical reduction and by adjusting the silver-coating process. By means of SEM, XRD, grain size analyser, digital ohmmeter and differential thermal analyser, the surface topology, structure and conductivity of silver-coated copper powder and raw copper powder are characterised. The results show that the spherical silver-coated copper powder has superior compact surface, complete coverage, a coated layer reaching a thickness of 336nm and excellent conductivity and anti-oxidation property.
Room-Temperature Ferromagnetism in Co-Doped SrTiO3 Nanofibres
Authors: Zhang Wei , Li He Ping , Pan Wei
Published: June 2012

In this article, Co-doped SrTiO3 nanofibres have been prepared by electrospinning from a sol-gel precursor and the following calcination at 923K. XRD results confirmed that no second phase was formed, and Co ions successfully occupied the Ti sites. By annealing in hydrogen, oxygen vacancies and (Co-H-Co) were formed, which both contributed to the magnetic ordering in SrTi1-xCoxO3 nanofibres are at 300K.
Photoluminescence Enhancement of CdS Nanocrystals Fabricated on Dithiocarbamate Functionalized PET Substrates
Authors: Zhao Chun Lin , Xing Li , Liang Xiao Hong , Xiang Jun Hui , Zhang Fu Shi , Cui Li Jie , Song Bo , Chen Shi Wei , Sai Hua Zheng , Li Zhen You
Published: June 2012

Cadmium sulfide (CdS) nanocrystals (NCs) were self-assembled and in-situ immobilized on the dithiocarbamate (DTCs)-functionalized polyethylene glycol terephthalate (PET) substrates between the organic (carbon disulfide diffused in n-hexane) –aqueous (ethylenediamine and Cd2+ dissolved in water) interface at room temperature. Powder X-ray diffraction measurement revealed the hexagonal structure of CdS nanocrystals. Morphological studies performed by scanning electron microscopy (SEM) and high-resolution transmission electron microscope (HRTEM) showed the island-like structure of CdS nanocrystals on PET substrates, as well as energy-dispersive X-ray spectroscopy (EDS) confirmed the stoichiometries of CdS nanocrystals. The optical properties of DTCs modified CdS nanocrystals were thoroughly investigated by ultraviolet-visible absorption spectroscopy (UV-vis) and fluorescence spectroscopy. The as-prepared DTCs present intrinsic hydrophobicity and strong affinity for CdS nanocrystals.
Preparation and Characteristic Development of Nano Zn2SiO4: Mn Green Phosphors by La2O3 Doping
Authors: Yang Fann Wei , Cheng Chien Min , Chen Kai Huang
Published: June 2012

In this experimental, solid state method is used to synthesize proportioned nano-ZnO and SiO2 powders into Zn2SiO4 phosphor, and to achieve better control on grain size and grain shape than traditional powder. La is used to replace Mn; and to achieve better control on grain size and grain shape than traditional powder. With different sintering conditions, With different sintering conditions, the effect of the luminescent intensity due to sintering temperature and the concentration of activator would be discussed by the X-Ray Diffraction, SEM and TEM were utilized in the characterization of phase purity and microstructure of phosphor particles. Photoluminescence (PL) spectroscopy was utilized to characterize the optical properties. This use of phosphor materials is the application of the main light source, display components. Therefore, our study zinc silicate as the main principle of doping Mn, La of the characteristics of, expects to find the best glow.