bluuebunny/crossref_metadata_2025 huggingface dataset:
Exciton Localization and Stimulated Emission of ZnO Nanorods
Authors: Li Chun Ping , Zhang Li , Liu Chang Jie , Gao Ge
Published: March 2013

High yield ZnO nanorods are synthesized by a simple wet chemical method. The crystal morphology and structure of the ZnO nanorods are examined by transmission electron microscopy (TEM) and X-Ray Diffraction (XRD), respectively. The properties of the excitonic luminescence are investigated by temperature dependent photoluminescence (PL) spectra. Barely observed visible emission band indicates the good optical quality of the ZnO nanorods and the abnormal position and intensity changes of the emission peaks indicates the localization property of exciton.
Determination of Transition Mechanism and Polarity of a c-Plane ZnO Bulk by Using Contactless Electroreflectance Spectrum
Authors: Tseng An Hai , Chiang Yei Fai , Wang Dong Po
Published: March 2013

Contactless electroreflectance（CER）spectra of Zn and O-polarity faces of a c-plane ZnO bulk were measured at room temperature. Besides a depletion electric field existing in the sample, it is known that there is a polarization electric field due to nonzero spontaneous polarization. In this work, a mercury lamp was focused on the ZnO sample in the CER measurements to provide a photo-biased voltage to reduce strength of electric field of the sample. It was found that the spectrum with Hg lamp being on is more blue-shifted and its amplitude is smaller than that without Hg lamp. Thus the type of transition was attributed to excitonic transition. The shift of the excitonic transition-energies of the Zn- and O-faces were obtained by fitting experimental CER spectra by using Lorenzian line-shapes. In addition, the polarity of faces can be determined by the amount of shift with Hg lamp being on.
The Morphology Effect on Ca-Bi-O System Photocatalytic Property under Visible-Light Irradiation
Authors: Wang Hai Ying , Xiong Ke , Hu Yan Chun , Zhang Ke Lei , Xiong Rui
Published: March 2013

Four main phases in Ca-Bi-O systems, Ca6Bi6O15, Ca4Bi6O13, CaBi2O4 and Ca5Bi14O26 were prepared by solid-state reaction method. UV-visible absorption spectra show that the samples of CaBi2O4, Ca4Bi6O13 and Ca5Bi14O26 have visible-light reactivity with the band gap of 3.08 eV, 2.76 eV and 2.60eV, respectively. The results of SEM and BET measurements indicate that CaBi2O4 has the morphology of flower-like nanostructure and the high BET surface area, while Ca6Bi6O15, Ca4Bi6O13, and Ca5Bi14O26 have the morphology of particles of various shapes with a diameter from 200 nm to 2 μm and low BET surface area. CaBi2O4 was found to be a most efficient visible-light-driven photocatalyst in degradation MB. This work may deepen the understanding of the relationship between the photocatalytic properties and the crystal structures in Ca-Bi-O system.
Influence of Hot-Pressing on Sintered Nd-Fe-B Permanent Magnets
Authors: Huang Qi Jun , Liao Zhi Qin , Yan Wei Jin , Xu Feng , Chen Guang , Li Shan Dong
Published: March 2013

In this work, we perform a post hot-pressing on the pre-sintered Nd-Fe-B magnet, and investigate its influences. The results show that the main influence on the magnetic characteristics is that it deteriorates the rectangularity of the demagnetization curves. Further investigations on density, grain size and crystal alignment show that the increases of density and grain size, and the decrease of crystal alignment with the hot-pressing. The discussion indicates that at the temperature higher than the melting point of boundary phase, the liquefying of boundary under uniaxial external pressure brings about the grain growth, the density increase, and the deviation of crystal alignment from the pre-aligned optimum position.
Effects of Compositional Variation on the Structure and Properties of Aluminoborosilicate Glasses
Authors: Zhang X.H. , Yue Y.L. , Wu H.T.
Published: March 2013

In alkaline earth aluminoborosilicate glasses CaO-B2O3-Al2O3-SiO2, the changes of structure and properties caused by variations in the ratio SiO2/B2O3 were investigated. The structure was investigated by Fourier transform infrared spectroscopy. The dielectric constant and tangent loss were measured at 1 MHz. Chemical durability was evaluated by weight losses of glass samples after immersion in HCl and NaOH solutions. The results indicated that the fraction of four-coordinated boron atoms (N4), chemical durability and dielectric properties increased with increasing SiO2/B2O3 replacements.
Effect of Li0.8Ca0.2F1.2 on Sintering and Microwave Dielectric Properties of (Mg0.95Zn0.05)(Ti0.8Sn0.2)O4 Ceramics
Authors: Yao Guo Guang , Ma Hong , Tian Xiu Lao
Published: March 2013

The effects of Li0.8Ca0.2F1.2 doped on the sinterability, phase constitutions and microwave dielectric properties of (Mg0.95Zn0.05)2(Ti0.8Sn0.2)O4 (MZTS) ceramics were investigated. The crystal structure was analyzed using X-ray diffraction. With 3.0 wt% Li0.8Ca0.2F1.2 addition, the densification sintering of MZTS ceramics was significantly lowed from 1325 oC to 1150 oC due to the liquid phase sintering. Secondary phases CaTiO3 and MgO were formed by reaction between MZTS and CaF2. 3.0wt% Li0.8Ca0.2F1.2-doped MZTS ceramics at 1150 oC for 5 h exhibited dielectric properties: εr=13.4, Qxf=46 672.3 GHz (at 9.3 GHz).
Study of High Functional WO3 Film Sensors for Practical NO2 Detection
Authors: Meng Zhi Cong , Hashishin Takeshi , Tamaki Jun , Kojima Kazuo
Published: March 2013

Four types of tungsten trioxide (WO3) particles (spherical, disk, cuboid, and hexagonal) were prepared and WO3thick film sensors were fabricated by dropping suspensions containing the obtained various WO3powders on Au comb-type microelectrodes. The sensing properties to 0.05-ppm NO2revealed that a cuboid WO3film sensor had the best response-recovery characteristics with the 90 % response and 90 % recovery times of 1.3 and 0.9 min at 200 °C, respectively. On the other hand, a hexagonal WO3film sensor showed extremely high sensor response even to 0.01-ppm NO2 at 200 °C, but the sensor response fluctuated greatly over the operating temperature range from 80 to 300 °C. Practical evaluation of the cuboid WO3thick film sensor in a roadside atmosphere was carried out and it was demonstrated that the evaluated values for the sensor unit had accuracy and resolution equivalent to CLD (Chemical Luminescence Detection) without any maintenance and calibration for 10 weeks.
Nanoscale ZnO Window Layer Textured 650nm Resonant Cavity Light Emitting Diode
Authors: Ma Ling Yun , Li Jian Jun , Li Jia Chun , Sun Pei , Deng Jun , Han Jun , Xing Yan Hui
Published: March 2013

We propose a simple technique to improve the light extraction efficiency of 650nm AlGaInP/GaInP resonant cavity light emitting diodes (RCLEDs) by using nanoscale textured-ZnO window layer. This layer was performed using a hydrothermal synthesis method, and the treatment solution for ZnO texturing growth on the RCLED surface was investigated. In addition, it has also been found that the optimum roughness of the nanoscale ZnO texturing for enhancing the light efficiency is about 300nm. As compared with the conventional RCLED, the nanoscale ZnO-textured RCLED, which has the optimum average roughness of 300nm, performs higher external quantum efficiency, a higher light output power, and a narrower spectrum width.
Preparation of Graphene Films and their Applications in Dye-Sensitized Solar Cells
Authors: Shen Tan , Shen Yue , Ma Xiao Tian , Gao Wen Ting , Cao Meng , Gu Feng , Wang Lin Jun
Published: March 2013

A facile and rapid deposition process is developed for the fabrication of large-area graphene films by scalpel technology using graphene nanopartical as material. Graphite oxide (GO) was synthesized using modified Hummers method. Graphene nanopartical was fabricated by a reducing process in which GO was well reduced by hydrazine hydrate. The crystal structure and photoelectric properties of graphene and graphene films were investigated by X-ray diffraction. The composition of production (GO and graphene) is investigated by Fourier Transform Infrared Spectroscopy (FTIR) and Raman spectroscopy technology. Surface morphology of graphene layers were observed by SEM. Then, the semitransparent conductive films were applied to backside illumination DSSC. As a result, the maximum power conversion efficiency (PCE) is as high as 0.2558% and the fill factor is 30.97%.
Thin Film Materials for Optical Interference Filters
Authors: Kosyachkov A. , Wang L. , Anzellotti J. , Hallock R. , Hodgson C.
Published: March 2013

Abstract. Microstructural, optical and mechanical properties of oxide and fluoride films are examined. Superior optical quality, durability and environmental stability are achieved for oxides deposited by ion assist reactive ion beam sputtering and thermal evaporation. The materials and deposition techniques are discussed with regards to manufacturing of optical interference filters for near-UV – mid-IR wavelengths. High performance of thin film materials and optical filters is demonstrated.
Effect of Precursor Concentration on the Ideal ZrO2 Sols and Thin Films
Authors: Wang Sheng Zhao , Zhang Li Na , Nan Chun Juan , Huang Da Yong
Published: March 2013

ZrO2 sols were prepared with hydrothermal synthesis method. The ZrO2films were characterized or examined by many kinds of instruments. With different content of zirconium oxychloride octahydrate, the particle sizes of ZrO2 sols are different from 3nm to 25nm. And 1-on-1 laser-induced damage threshold tests on ZrO2 films were carried out with a Q–switched Nd-YAG high power laser at 1064 nm. The experimental results showed that the ZrO2 sols is suitable for preparing ZrO2thin film and the refractive index and thickness of this thin films achieve our requirement.
Experimental and Simulation Study of Microhardness Indentation of Solid Oxide Fuel Cell Using Progressive Damage Material Model
Authors: Zhang Jing , Liu Jia Yang
Published: March 2013

A finite element model with progressive damage material properties is proposed to study the mechanical behavior of Ni-8YSZ/8YSZ half-cell structures under Vickers indentation tests. The simulation results show that the simulated hardnesses of the as-received anode (NiO-8YSZ with 12% porosity) and the reduced anode (NiO-8YSZ with 36.68% porosity) samples were 2.54 GPa and 0.66 GPa, respectively, which are fairly in agreement with the experimental data. The interface delamination between the anode layer and the electrolyte layer was investigated by varying the mechanical properties of the interface between the two layers. The parametric study shows that a weak interfacial layer (with a low Young’s modulus) may cause potential failure due to delamination.
Seismic Behaviour of RC Columns Strengthened with Steel Bar/Wire Mesh Mortar
Authors: Sun Yan Hua , Wu Xio Yong , Xiong Guang Jing
Published: March 2013

In order to enhance the seismic behavior of reinforced concrete (RC) columns more efficiently, a thought to strengthen concrete columns by using steel bar/wire mesh mortar （FS）was proposed. An experimental study including five RC square columns strengthened with FS and steel bar mat mortar (S), respectively, under constant axial loading and lateral cyclic loading was carried out. Seismic bearing capacity, ductility, failure modes and hysteretic characteristics of all columns were tested, and the effect of reinforcement ratio and strengthening method to the tested columns was analyzed. The results showed that the energy dissipation capacity of FS strengthened columns was 73% higher than that of the S strengthened column, though the reinforcement ratio of the former was only 3.02% higher than that of the latter.
Effect of Fly Ash on Resistance to Sulfate Attack of Cement-Based Materials
Authors: Liu Kai Wei , Deng Min , Mo Li Wu
Published: March 2013

The resistance to sulfate attack of mortars containing 0%, 20%, and 40% of fly ash cured in 5 wt. % sodium sulfate solution at 20°C was investigated in this paper. Visual appearance, cracking analysis, velocity of ultrasonic wave and length change were applied to evaluate the sulfate resistance of mortars. The phases and microstructure of the reaction products due to sulfate attack were examined by XRD and SEM, and the pore structure of the mortars was analyzed by MIP. The effects of fly ash on the sulfate attack of mortars were analyzed. Results indicated that the addition of fly ash improved the resistance of sulfate attack significantly, this probably contributed to the pozzonlanic reaction of fly ash.
Study of Durability Analysis and Evaluation Model for Existing Concrete Structure in Coastal Areas
Authors: Yu Hai Yong , Zhang He
Published: March 2013

This article put forward the durability state analysis method for existing concrete structure based on the step analysis theory and environmental load feature of east coast in China. Considering the process of both concrete degradation and steel corrosion, this article also established the residual life prediction model of existing concrete structure, based on a whole life prospective period. The model was successfully applied to evaluate the durability state and residual life of certain existing concrete structures, including dock structure in Hangzhou Bay and matching construction of Expo, 2010.
An Experimental Study of Water in Pore System of Hardened Cement Paste by Magnetic Resonance
Authors: She An Ming , Yao Wu , Yuan Wan Cheng
Published: March 2013

The water distribution in hardened cement paste with different ages, water to cement ratio (w/c) and different cured methods were investigated by low field NMR. The transverse relaxation time, T2, was used as a parameter to describe the water phase constrained in pores. The results show that the T2 distributions of pastes in the early age are bimodal distribution. As the curing time increase, the T2 distribution peaks shift gradually to the short T2 values reflecting the decrease of mean pore dimension as well as the increase of specific surface area resulted from the gel products. In addition, the influences of initial water to cement ratio and cure methods on water distribution are occurred mainly during the early age. When cured to 28 days, the differences of water distribution in various samples are unconspicuous.
Tentative Study on Sonoelectrochemical Chloride Extraction from Mortar
Authors: Chen Yi Qun , Yao Wu , Xing Xiao Ming
Published: March 2013

This paper presents the first use of ultrasound technique during electrochemical chloride extraction (ECE). The effect of ultrasound on the extraction efficiency was studied, and the mechanism of ultrasound in improving the extraction efficiency was also discussed in this paper. Testing results showed that ultrasound was conducive to enhance the efficiency of chloride removal to a certain extent, especially in the first 3 weeks. Ultimately, compared with ECE treatment, the chloride removal efficiency of ultrasonic-assisted ECE nearly increased 10%. In addition, the corrosion potentials measured 2 months after treatment indicated the effectiveness of ultrasonic-assisted ECE in protecting eroded rebars from further corrosion.
Solubility Behavior of the Hydration Products in the Pore Solution of Hydrated Cement Pastes
Authors: Yao Wu , Wu Man Jian
Published: March 2013

The concentrations of Ca, Al, Si, Na, K, SO42- and pH value in the pore solution of Portland cement were measured during the first 28 days of hydration at room temperature. A thermodynamic analysis of the elemental concentrations was used to predict saturation indices of various solid phases known to form in normal cement system. During the first 4 h the composition of pore solution is dominated by K+, Na+, SO42-and OH-. Large and rapid changes in the concentrations of Ca2+, SO42- and hydroxyl occurred between 4 h and 24 h, and thereafter the pore solution is essentially one of alkali hydroxides. Portlandite and calcium monosulfoaluminate was slightly supersaturated after the first few hours. Saturation indices calculations for ettringite and C-S-H indicate the high levels of supersaturation until 28 days.
Influence and Mechanisms of In Situ Toughening Telechelic Polymer on the Microstructure of Concrete
Authors: Zhu Xiao Bin , Feng Pan , Liu Jia Ping , Ding Bei , Hong Jin Xiang
Published: March 2013

To find out the toughening mechanism of in-situ toughening telechelic polymers (ITTP) in concrete, SEM & EDS and Nano indenter were used to research the variation of concrete hydration products and the interfacial transition zone between the cement paste and aggregate. The results indicate that the toughening effect of ITTP is not carried out by film formation. And the proportion of LD C-S-H in cement hydration products increased significantly and the CH content decreased after introducing the ITTP into concrete. Nano indentation test results show that the non-dense area ratio of ITZ decreased, and the CH content in ITZ increased slightly. The Ca/Si blurred from mutation pattern with decreasing the distance to aggregate surface in the region of interfacial transition zone between aggregate and cement paste, and the thickness of ITZ increased. The conclusions show that the ITZ and hydration products are both key micro-structures which affect the toughness of concrete, and it provides us some guidance for realizing concrete toughness ascension through microstructure adjustment.
Research on the Application of Liquid Permeating Method to Silica Sol Stability
Authors: Li Le , Zhou Nai , Cui Xu , Huang Wen Hai
Published: March 2013

The stability of SiO2 sol is an important parameter in the practical applications. But so far the parameter for expressing the stability of SiO2 sol cannot be characterized by a proper measurement. In this paper, a new method, liquid permeating method, was introduced, by which the stability of SiO2 sol was characterized and the effects of additive, such as dimethylformamide (DMF) and MgO were presented. The results show that with the amount of DMF increasing, the gel-time of SiO2 sol became longer; and that with the amount of MgO increasing, the gel-time became shorter. The results obtained by this new method are as same as that from the traditional tedious viscometer measurement method, which indicate that this liquid permeating method is a reliable method for characterizing the stability of SiO2 sol. Besides, this liquid permeating method is also simple, time-saving and low-cost for evaluating SiO2 sol stability.
An Evaluation of Shrinkage Model Based upon Microstructure of Blended Cement Pastes
Authors: Chen Yi , Yao Wu , Jin Dan
Published: March 2013

As shrinkage in concrete leading to the subsequent cracking and reducing durability, the study on shrinkage is quite important. Based on microstructure of pores obtained from Nitrogen absorption method and mechanical testing, a numerical shrinkage model was built. The standard shrinkage test results show consistent in the blended cement pastes with different water-to-cement ratioand admixture content to predict shrinkage values, which confirmes the shrinkage model based upon microstructure of blended cement pastes.
Early-Age Free Shrinkage of Mortars with Different Dosages of EVA Redispersible Powder
Authors: Liu Si Feng , Wang Pei Ming
Published: March 2013

The plastic free shrinkage evolutions of mortars in the presence of different dosages of redispersible Ethylene-vinyl acetate (EVA) copolymer powder were measured using the laser sensor at acceleration dry for 6 hours. The effects of temperature, relative humidity, air contents and water evaporation of mortars on the plastic free shrinkage were observed. The plastic free shrinkage of mortars declines firstly and then rise under the increasing dosage of EVA powder in range of 1%~10% mass of cement in mortars, the plastic free shrinkage of mortars with 10% EVA powder was almost closed to that of plain cement mortars. The EVA powder facilitates a decrease in plastic free shrinkage of mortars. The linear regression equation between the plastic free shrinkage and its effect factors was set up, and analysis of variance was used to analyze the significant of air content and water evaporation.
Probing Nanostructure of Calcium Silicate Hydrate by AFM and Nanoindentation
Authors: Liang Kang , Yao Wu , Chen Lin Jie , Gao Qun
Published: March 2013

It is important to study the nanostructure and mechanical properties of calcium silicate hydrate at the nanoscale for it is the main binding phase in Portland cement paste. In this paper, atomic force microscopy and nanoindentation (NI) were combine used to determine the morphology and mechanical properties of Calcium Silicate Hydrate (C-S-H) at microscale. It is found that C-S-H is made of globules from size of 50 nm to 300 nm irrelevant with water-to-cement ratio and ages in nanostructure, and we suggest that the maximum load for NI testing of the C-S-H is no more than 2 mN.
Mechanical Property of Hybrid Steel Fiber Reinforced Cement-Based Composites
Authors: Tan Hai Tao , Yao Wu , Song Xiao Ming , Dong Shuai
Published: March 2013

The ultimate load, fracture energy and equivalent bending strength of hybrid steel fiber reinforced mortar were investigated with a constant fiber volume fraction in this paper. The results showed that ultimate load of hybrid steel-fiber reinforced mortar was higher than that of mono-fiber reinforced mortar; fracture energy and equivalent bending strength increased with the volume fraction of steel fiber with end hooks.
A Comparative Study between Melt-Derived and Sol-Gel Synthesized 45S5 Bioactive Glasses
Authors: Lombardi Mariangela , Gremillard Laurent , Chevalier Jérôme , Lefebvre Leila , Cacciotti Ilaria , Bianco Alessandra , Montanaro Laura
Published: March 2013

In the last years, bioactive glasses and glass-ceramics drew the attention for their application in the production of implants. Among them, Bioglass®45S5 is the most commonly used in terms of bioactivity, but its sintering behavior and the related glass-ceramics strongly depend on the followed synthesis process. For these reasons, this paper reports a comparison of the properties and the thermal behavior of bioactive 45S5 glasses produced by a conventional melting process starting from suitable solid precursors or an innovative sol-gel procedure.
Current Problems in Design of Quantum Dots Used in Semiconductors
Authors: Banaś Aleksander , Muc Aleksander
Published: March 2013

The analysis of optoelectromechanical properties of nanostructures in bandstructure engineering is discussed In the paper. It is demonstrated that the design of semiconductors is based on the solution of different forms of the Schrodinger (Helmmholtz) equation, dependant on the form of the Hamiltonian characterizing quantum effects. The formulation can lead to the linear or nonlinear eigenvalue problems. Then, the methods of solutions are also presented.
Dodecane Sensing with Double Substituted LaCoO3 Nanowires Deposited by Reactive Magnetron Sputtering
Authors: Yazdi Mohammad Arab Pour , Sanchez Jean Baptiste , Monsifrot Eric , Briois Pascal , Berger Franck , Billard Alain
Published: March 2013

This paper reports results of dodecane-sensing studies with double-substituted LaCoO3 perovskite oxide nanowires. La0.40Sr0.15Ag0.45CoO3-α nanowires were co-sputtered from metallic La, Sr, Ag and Co targets in the presence of a reactive argon-oxygen gas mixture. As deposited coatings are amorphous and crystallise in the perovskite structure after annealing at 873 K for 2 hours under air. Electrical response of the La0.40Sr0.15Ag0.45CoO3-α nanowires was measured at different temperature under air and under air containing 1 to 100 ppm (v) of dodecane vapour. The electrical signal of the nanowires was found to be high and it was possible to detect low concentrations of dodecane (under 5 ppm (v) ) at 573 K.
Effect of CTAB Concentration on Synthesis and Sensing Properties of Perovskite Oxide via a Hydrothermal Process
Authors: Yao Peng Jun , Wang Jing , Du Hai Ying , Zhao Lin , Yan Wei Ping
Published: March 2013

La0.7Sr0.3FeO3 materials with morphologies including nanoparticles, nanorods and nanowires were synthesized via a hydrothermal process assisted with different cetyltrimethyl ammonium bromide (CTAB) concentration. XRD, SEM and BET were used to characterize the morphology, composition and structural properties of the nanomaterials. The effect of CTAB concentration on morphology and growth mechanism of La0.7Sr0.3FeO3 was discussed. The gas sensing properties of La0.7Sr0.3FeO3 materials with different morphologies were also carried out in 0.1~ 100 ppm formaldehyde.
Room Temperature Fluorescence Gas Sensor Based on Coated TiO2 Nanoparticles
Authors: Yusoff Nurul Huda , Salleh Muhamad Mat , Yahaya Muhammad
Published: March 2013

Room temperature fluorescence gas sensor was developed based on TiO2 nanoparticles coated with porphyrin dye thin films. The porphyrin dye used for this experiment were Iron (III) meso-tetraphenylporphine chloride (IMTPPCl) and Manganase (III) 5,10,15,20 tetra (4-pyridyl)-21H, 23H porphine chloride tetrakis (metachloride). The sensing sensitivity was due to the changes of the emission spectra produce by the thin film when expose to the organic vapors from volatile organic compounds; ethanol, acetone and 2-propanol. Both thin films show good response toward volatile organic vapors. However, TiO2 nanoparticles with porphyrin; IMTPPCl thin film shows pronounced interaction, marked fluorescence spectra and more selective property, hence useful for chemical identification purpose.
Improving the Performance of High Temperature Piezopolymers for Magnetoelectric Applications
Authors: Gutiérrez Jon , Lasheras Andoni , Barandiaran Jose Manuel , Vilas Jose Luis , Maceiras Alberto , León Luis Manuel
Published: March 2013

Piezoelectricity in amorphous polymers is mainly due to the orientation polarization of the molecular dipoles. Aromatic polyimides are high-performance polymeric materials possessing large molecular dipoles. We already reported good magnetoelectric performance of laminate composites with Vitrovac 4040® as magnetostrictive component and the 2,6(b-CN)APB/ODPA (poli 2,6) polyimide as the piezoelectric. Although the piezoelectric response of this polyimide is good, its mechanical properties can be improved. To combine the best mechanical and piezoelectric response in the same polymer, copolyimides have been synthesized by reaction of the 4,4-oxydiphtalic anhydride (ODPA) with a mixture of 1,3-Bis-2-cyano-3-(3-aminophenoxy) phenoxybenzene (diamine 2CN) and 1,3-Bis (3-aminophenoxy) benzene (diamine 0CN). We present the piezoelectric, mechanical and ME performance of laminate composites of these copolyimides.
Preparation of High Performance Pt Counter Electrodes on Conductive Plastic Substrate for Flexible Dye-Sensitized Solar Cells
Authors: Wang Ya Qi , Zhang Qing Hong , Wang Hong Zhi , Li Yao Gang
Published: March 2013

Pt counter electrodes (CE) were been prepared using ion sputtering method on indium-doped tinoxide coated polyethylene terephthalate (ITO-PET) for ﬂexible dye-sensitized solar cells (DSSCs). The effect of sputtering time on the properties was characterized by Feld emission scanning electron microscope (FESEM), electrochemical impedance (EIS) and UV-vis absorption spectra. The flexible CE show increased catalytic activity but reduced transmittance when the sputtering time is increased from 0 to 80 s. The light-to-electricity conversion efﬁciency of the DSSCs assembled with the high catalytic activity ﬂexible CE attained a conversion efﬁciency of 4.0% by using Ti foil as the photoanode substrate under the simulated AM 1.5 sunlight. The results reveal that ion sputtering is an effective method for depositing platinum nanoparticles on plastic substrates with low cost under room-temperature.
Effects of Sol Network Modifiers on Preparation, Morphology and Phase Composition of Zirconium Diboride Nano-Powders by Novel Sol-Gel Technology
Authors: Ji Guang Yi , Ji Hui Ming , Li Xiu Ping
Published: March 2013

Zirconium diboride nano-powders were synthesized by novel sol-gel technology using zirconium oxychloride, boric acid and sucrose as row materials. Different sol network modifiers, such as propylene oxide (PO) and citric acid (CA), were used to control the formation of zirconia precursor sol, respectively. PO could stabilize the sol by protonation and ring-opening reactions, and CA could form the sol network by chelation, then transformed to gel network. Gel was dried, ground, and exposed to carbonthermal reduction heat treatment (1500°C, 2h, flowing 95%argon mix with 5% hydrogen) to prepare ZrB2 nano-powders. In this study, effects of sol network modifiers on preparation procedure, powder characteristics were performed by using Infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Transmission electron microscopy (TEM). The purity of ZrB2 will improve by increasing the molar ratio of B/Zr, the photomicrograph revealed nearly pure ZrB2 nano-powders with spherical shape of 50-200nm and well dispersed were obtained with a molar ratio of B/Zr of 3.0 at 1500°C for 2h using PO as chemical modifier.
The Preparation and Characteristics of MMT Nanosheets
Authors: Chen Cheng , Wu Hao , Li Qiang
Published: March 2013

Montmorillonite (MMT) mainly consist of hydrated aluminum silicate. Montmorillonite has particular properties and many practical applications, because of their special crystal structure. Here, mechano-chemical method was used to prepare MMT nanosheets by controlling the pH value. MMT nanosheets were obtained by ballmilling, and the impact of pH value on the nanosheets preparing was studied. TEM was employed to emamine the microstructure of MMT nanosheets. The size are analyzed to study the status of MMT nanosheets. Different rare earth ions as a fluorescence center were assembled on nanosheets，and composites were obtained. The luminescent properties of composite materials were studied.
Synthesis of LaFeO3 Nano-Powders by Self-Propagating Combustion Method of Sol-Gel
Authors: Zhu Yan Feng , Liu Wei Liang , Wu An Hua , Feng Zhen Qian , Wang Chuan Yong , Xu Jun
Published: March 2013

Nanocrystalline LaFeO3 with particle size of about 50 nm was directly synthesized by sol–gel auto-combustion method at room temperature. The overall process involves three steps: formation of homogeneous sol; formation of dried gel; and combustion of the dried gel. Single phase nanocrystalline LaFeO3 powders were successfully synthesized by the sol–gel self-propagation combustion method using glycin (C2H5NO2) as the chelating agent. Discuss the synthesis products by DTA/TG, XRD and SEM. The experiment results show that the LaFeO3 nano-powder was got from dried gel of G/M=1:1 at 300°C ignition temperature and then holding 2h at 800°C.The LaFeO3 nano-powder is about 50nm with excellent dispersibility. The hysteretic loop show LaFeO3 nanopowders have the character of ferromagnetism, the coercivity of the nanocrystalline LaFeO3 is 99G, while the saturation is only 2.8 emug-1.
Microstructure Analysis of the ZrO2/Al2O3 Multi-Phase Ceramics
Authors: Chen Zhi Wei , Niu Jin Ye , Feng Liu , Liu Dong Wu , Wei Xiao Bing
Published: March 2013

Scanning electron microscopy (SEM) with X-ray mapping analysis was applied to systematically study the microstructure of ZrO2/Al2O3 multi-phase (ZTA) ceramics prepared by firstly cold isostatic pressing of the as-prepared powders with different formulas and then normal pressure sintering of green bodies at different temperatures, which was proposed to illustrate the toughening mechanism of ZrO2 phase as well as the effect of the microstructure on the fracture toughness of the ZTA ceramics. In addition, XRD analysis was carried out to characterize the phase composition and validate the mapping data from microanalysis. Results obtained in this study demonstrate that the amount of sintering aids added to decrease the sintering temperatures as well as the distribution of ZrO2 particles in Al2O3 particles both play key roles in the microstructure and fracture toughness of ZTA ceramics, which indicates that microanalysis have important directive to the preparation of multi-phase ceramics with high performance.
Synthesis and Photo-Catalytic Properties Characterization of Graphene/TiO2 Nanotube Composites
Authors: Li Cai Xia , Zhang Lin , Jiang Dan Yu , Li Qiang
Published: March 2013

Selecting graphene oxide (GO) and the Degussa P25 TiO2 (80% anatase and 20% rutile) as raw materials, the composites of graphene/TiO2 nano-tubes were simply and quickly prepared under the conditions of a concentrated solution of sodium hydroxide. The as-obtained composites’ phase structure was analyzed and characterized by powder X-ray diffraction (XRD), their morphologies were also observed and cross-confirmed under the Transmission Electron Microscopy (TEM). The measurements showed that the composites prepared in this work have a remarkable structure, and compared to the seperate TiO2 nano-tubes, the agglomeration of TiO2 nano-tubes covered on the surface of the graphene is apparently not so serious. In view of this, we preliminary tested the composites’ photo-catalytic performance with the visible light irradiation, and also made a comparison with TiO2 nano-tubes.
Properties of Li-Doped ZnO Films Deposited on Diamond Films
Authors: Lin Mei Ai , Wang Lin Jun , Huang Jian , Tang Ke , Ren Bing , Zhou Jie , Xia Yi Ben
Published: March 2013

Li-doped zinc oxide (ZnO) films were deposited on nucleation side of freestanding diamond (FSD) films by the radio frequency magnetron sputtering method. The effect of oxygen partial pressure on structural, optical and electrical properties of the ZnO films was investigated by X-ray diffraction (XRD) Raman spectroscopy, semiconductor characterization system and Hall effect measurement system. The results showed that the introduction of oxygen as a reactive gas was helpful to improve the crystalline quality of Li-doped ZnO films.
Effects on Cold Modulus of Rupture and Cold Crushing Strength of One Low Cement Refractory Castable (LCRC)
Authors: Li Kun Ming , Xue Fei , Xie Jin Li , Li Chun Yan , Li Li Ping , Lin Guo Wei , Pan Chuan Cai , Zhang Lin Lin
Published: March 2013

Cement addition, water addition and wet curing period are selected as the effects on cold modulus of rupture and cold crushing strength of one LCRC. According to the molding morphologies of the castables, when the water addition is 8 wt. %, the castable is suitable to be cast by vibration fashion, and the high strength of the castable can be kept because the hardening time is not very long. Through an orthogonal experiment, it is shown that cold modulus of rupture and cold crushing strength increase with increasing cement addition, decrease with increasing water addition, almost do not affect by the wet curing period. It is recommended that 4 wt. % cement addition and 8 wt. % water addition of the castable are used when it is applied to industries.
Ballistic Performance of TiC-TiB2 Composite Armour under the Impact of Long-Rod Tungsten Alloy Projectiles of 1.4 km · s-1
Authors: Huang Xue Gang , Zhao Zhong Min , Zhang Long
Published: March 2013

Based on using combustion synthesis in high-gravity field to prepare the solidified TiC-TiB2 composites, the layered composites of the ceramic to Ti-6Al-4V at graded composition were achieved by fusion joint and atomic inter-diffusion between liquid TiC-TiB2 and Ti-6Al-4V substrate. The mechanical properties showed that the relative density, micro-hardness and fracture toughness of TiC-TiB2 ceramic layer measured 98.5%, 21.5 GPa and 13.5 ± 2.5 MPa • m0.5, respectively, and the shear strength at joint of TiC-TiB2 to Ti-6Al-4V measured 450 ± 25 MPa. By conducting DOP test to evaluate ballistic performance of the ceramic and layered-composite targets against long-rod KE projectiles at impact velocity of 1.4 km • s-1, it was obtained the mass efficiency 3.28 of the solidified TiC-TiB2 was achieved as the impact point of the projectile was nearby the centre of the target, whereas the mass efficiency 3.18 of the layered composite with the solidified ceramic to Ti-6Al-4V was also achieved even if the impact point of the projectile was at the edge of the target. By combining penetration damage of the targets with the dynamic behavior of the ceramic, it was obtained that the layered composite achieved by the joint of the solidified ceramic to Ti-6Al-4V not only improve ballistic performance of the ceramic, but also weaken the sensitivity of the ceramic target against the impact point of KE projectile by tearing the joint of the ceramic with Ti alloy to restrain formation and propagation of conical crack and fracture cone in the ceramic.
Properties Analysis of Corundum Castables and Corundum MA Spinel Castables
Authors: Ding Cheng Dong , Zhang Gang , Yang Jian Hong
Published: March 2013

Due to its excellent properties and good workability, castables is widely used in metallurgical field especially in steel and nonferrous metallurgical industry. In this article, we mainly had a comparative analysis of corundum castables and corundum MA spinel castables with 15% and 30% MA spinel addition . The physical and mechanical properties such as the bulk density, apparent porosity, cold modulus of rupture, cold crushing strength and thermal shock resistance of samples were studied after different temperature heating treated at 110°C×24h, 1100°C×3h and 1400°C×3h, respectively. The thermal conductivity of different samples at 750°C were tested by plate heat conduction method, phase composition and microstructure of samples with 15% MA spinel addition after different temperature heating treated were tested by XRD and SEM respectively. The results showed that: the properties of corundum MA spinel castables with 15% MA spinel addition is relatively good, the corundum castables take second place, samples with 30% MA spinel addition showed the worst performance among the three. After the heating treatment at 1400°C×3h, the CCS and CMOR of the samples is higher than that of 110°C×24h and 1100°C×3h due to the CA6 formation. Coefficient of thermal conductivity of the corundum-based castables at 750°C is relatively higher compared with that of 15% and 30% MA addition, reaches at 1.260w/ (m.k).
NO2 Response of Solid Electrolyte Sensors Made Using ZnFe2O4 Electrode
Authors: Wang Qi , Hou Wei Hua , Feng Tao , Jiang Dan Yu
Published: March 2013

ZnFe2O4 powders are synthesized by solid phase method and used to make sensing electrode. Electrochemical cells are prepared with an oxygen ionic conductor (Y2O3-stabilized ZrO2: YSZ) with a semiconducting oxide (ZnFe2O4) electrode. Pt is used as the counter electrode. The devices shows promising NO2 sensing performance at 450, 550 and 650oC.The electromotive force (EMF) value of the ZnFe2O4/YSZ/Pt sensor increases with the increasing of concentrations of NO2 in N2.
Bonding and Electrochemical Property Test of Zirconia Ceramics
Authors: Huan Chang Tian , Jiang Dan Yu , Liu Ge Ming , Li Qiang
Published: March 2013

There are many bonding methods of the ceramic sintered body, such as diffusion bonding, glass bonding, and reports in this regard are not difficult to see. But the solid electrolyte zirconia ceramic bonding in NOx sensor is rarely reported. Here we use zirconia and aluminum-silicon glass together to bond zirconia ceramic sintered body, and tested the electrochemical performance with AC (alternating current) impedance spectroscopy, EMF (electromotive force) of the adhesive layer. The results indicates that the the electrochemical performance is good.
Study on Biocompatibility of Nano-TiO2 / Titanium Alloy
Authors: Liu Hua , Guo Li Qiang , Cheng Jin Ming
Published: March 2013

Nanometer titanium dioxide powders were prepared by hydrolysis of titanium-tetrabut- oxide with ethanol. Using the process that titanium alloys were embedded by the nanometer TiO2 powders and sintered in the high temperature furnace, the nano-TiO2 / titanium alloy biomaterials was fabricated out. The particle size of TiO2 particles on the surface of Ti alloy was mainly 50-70 nm. The experimental results indicated that the films of nanocrystalline titanium oxide powders on the surface of Ti alloy were with an excellent biocompatibility. By cultivation in the simulated body fluid for 7 days, the Ca phosphates were deposited on the specimen surface, and n (Ca) / n (P) atom ratio is about 1.61:1, which is similar to that of HA and human bone. The nano-TiO2 / titanium alloy possessed favorable cell compatibility testified by the cell cultivation experiment.
Research on Performance of Photovoltaic Insulating Glass Modules in Building Integrated Photovoltaic (BIPV)
Authors: Den Xiao Ying , Wu Xiao Li , Wei Chen Guang
Published: March 2013

A new type of photovoltaic insulating glass module was designed with three pieces of glass and two layers of EVA glue and solar battery and insulating layer in Building Integrated photovoltaic. Data acquisition and simulation experiment were conducted in outdoor of Xi'an by photovoltaic insulating glass modules. The modules' power performance difference was present in those conditions of different irradiation intensity and work temperature from May to October was analyzed. The application of photovoltaic insulating glass modules in photovoltaic was discussed primarily .The results show that the change of working temperature is very sensitive by photovoltaic insulating glass modules.
Absorption Enhancing Effect of Sodium Dodecyl Sulfate on Metformin Hydrochloride in Rat Colon
Authors: Jing Dong Dong , Liu Yu , Liu Ruo Yu , Fan Hua , Li Guo Feng , Shao Long Quan
Published: March 2013

The aim of this study was to observe the absorption enhancing effect of sodium dodecyl sulfate on metformin hydrochloride in colon of rat. Using in vivo intestinal loop model in rat while the ileum was took as blank group and colon as the experiment groups with different concentration of sodium dodecyl sulfate (1%, 2%, 4%). The colon/ileum ratio of the absorption rate constant of metformin hydrochloride was evaluated through calculating the residual dose of circulating solution in presupposition time points. Intergroup absorption rate constant and the rising percent of the absorption rate constant were different significantly (P<0.05). The absorption rate constant of colon were -0.22±0.03, -0.37±0.06, -0.89±0.09, -0.86±0.05μg•h-1•cm-1 (n=6) and the rising percent of the constant absorption value were 68.66 ± 8.28%, 304.88 ± 28.76%, 293.75 ± 33.19% (n=6), respectively. The result showed that the absorption of metformin hydrochloride was increased with the concentration of sodium dodecyl sulfate. However, the absorption rate constant reached maxium when the concentration of sodium dodecyl sulfate was 2%, this may be because the circulating metformin hydrochloride solution could be more viscous which affect the absorption of metformin hydrochloride when sodium dodecyl sulfate was raised. In conclusion, the absorption of metformin hydrochloride can be promoted by sodium dodecyl sulfate in the colon of rat and this can provide biophamaceutics data for novel pharmaceutical preparation.
A Sample Holder for X-Ray Powder Diffraction Studies of Flakiness and Block Sample
Authors: Zhang Hua Yong , Liu Xiao Jian , Sun Hai Yan , Fan Chun Sheng
Published: March 2013

Powder X-ray diffraction (XRD) is one of the primary techniques used to characterize solid state materials. But there is not a sample holder which can be fit into the sample carrier of the Bruker D8-Advance x-ray powder diffractometer for flakiness and block samples test. In this article, we will design, manufacture and evaluate a sample holder for flakiness and block samples. Materials of the holder are steel, glass and plasticine etc. The holder is low cost, easy to be processed, convenience to prepare the samples, and accurately obtain the best analytical results.
Experimental Research on Granule Moisture Measurement by Microwave Resonance Technology in a Fluidized Bed Dryer
Authors: Xie Yun Hui , Chen Lan , Lin Chun Hua , Du Song
Published: March 2013

Drying is one of the most important methods for industrial processing while the granule moisture is a critical quality attribute (CQA) which has a significant influence on the finished product quality. In-line measurement of granule moisture during fluidized bed drying is getting more imperative to meet more stringent product quality specifications. Nowadays, several methods have been applied to measuring the granule moisture in-line. Comparing to other methods, microwave resonance (MR) technology provides more representative results due to its independency of both the particle density and the bed density. In the current study, one MR sensor was mounted onto an industrial fluidized bed dryer to monitor the real-time moisture of granules. The drying experiments were performed at different drying air temperatures and flow rates. The comparison between the results of in-line and off-line granule moisture measurements, namely MR technology and loss on drying caused by infrared light (LOD/IR), was presented. Furthermore, the influences of inlet air temperature and flow rate on the performance of the MR sensor were investigated. As a conclusion, the MR method, which is independent of the drying air temperature and flow rate, provided more accurate results when the granule moisture was below 25% (wet basis). Therefore, it is a promising method to be applied in real-time measurement of the granule moisture and predict the end-point in fluidized bed drying processes as well.
The Study of Equipment for Testing High Temperature Elastic Modulus Based on the Acoustical Resonance Method
Authors: Qiu Yi Fu , Niu Qin Zhou , Qiu Yan , Bao Yi Wang
Published: March 2013

A self-designed testing device for high-temperature elastic modulus was developed based on the principle of acoustical resonance, having great accuracy and repeatability. Experiment was made to test the elastic modulus of two kinds of glass. The experimental data showed that compared with normal glass, Al2O3•SiO2 glass was the 1.2 times the value of elastic modulus of normal glass and had greater stability than normal glass in high temperature. The softening point temperatures of Al2O3•SiO2 glass and normal glass were respectively 600°C and 400°C. The self-designed testing device was able to estimate the property of glass.
Usability of Effective Medium Model for Microwave Absorbing Ceramics
Authors: Zeng Zhao Yang , Liu Heng , Guo Yi Min
Published: March 2013

For the purpose of describing the microwave properties of microwave absorbing ceramics, the usability of effective-medium theory for this kind of materials was investigated. Different equations deduced from effective-medium theory were first discussed and then compared with the measured data of microwave absorbing sample. It was found that the theory could not explain the measured data well only if some empirical exponent were used.
Study on Minimum Teeth without Undercutting of Involute Gears with 14.5 Degree Pressure Angle
Authors: Zhang Chao , He Jia Ning , Gao Yong , Deng Xu Lei
Published: March 2013

Study on minimum teeth without undercutting for considering the rack cutter’s addendum c*m of a kind of gear with 14.5 degree pressure angle, and the gear standard No is B436-1940 and used in UK. Based on the generating method, reasons for undercut phenomena is analyzed, and the numbers of minimum teeth without undercutting of the involute spur gear, involute helical cylindrical gear and involute spur bevel gear are theoretically analyzed and figured out. The correct number of minimum teeth without undercutting of gear with 14.5 degree pressure angle is given, and also illustrated the validity of theoretical derivation.
Improve the Profit from Principal Operations of Our Listed Ceramic Companies through Test Technology and Quality Management
Authors: Hua Rong Hui
Published: March 2013

During more than thirty years’ development, China ceramics industry can compete with peers from other countries. But we have few high-end products and no internationally well-known bands. So we have no capacity to control the price on global market. Our listed companies should focus on principal business through test technology and quality management. And what’s more, industrial policy and state policy should support their innovation.