bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal Shock Resistance of Plasma Sprayed Multi-Layered Functionally Graded Cr3C2-NiCr Coatings
Authors: Fu Dong Xing , Liu Jing Na , Liu Er Bao , Cai Zhao Bin , Cui Xiu Fang , Jin Guo
Published: April 2016

The interface properties of multi-layered functionally graded Cr3C2-NiCr coatings deposited by plasma spraying technique were experimentally studied in this paper. The microstructure and phase structure of coatings were studied with scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The thermal shock resistance was investigated by cyclic heating and cooling tests using an electro-calefaction furnace. The crack appearances of the coatings were observed carefully. Results show that the plasma sprayed multi-layered functionally graded coatings are compact and the adhesion between the layers and the substrate is good. The coatings have better macro-hardness than the substrate, and the 6-layers coating has the highest macro-hardness and the best wear resistance. Besides, the micro-hardness of coatings increases with increasing content of Cr2C3 in coating materials. Results of cyclic thermal shock show that the main failure styles of the coatings are crack and desquamation and the thermal shock resistance of the coatings is improved obviously by increasing the number of coating layers.
Microstructure, Texture and Inhibitors of the As-Cast and Hot Rolled Grain-Oriented Silicon Steel by Strip Casting
Authors: Liu Wen Qiang , Lei Cheng Shuai , Tang Han Mei , Song Hong Yu , Liu Hai Tao
Published: April 2016

The microstructure and texture evolution of the as-cast and hot rolled grain-oriented silicon steel strips was investigated, and the precipitation of the inhibitors of the hot rolled strips was clarified. The results showed that the microstructure of the as-cast strip was characterized by coarse columnar grains with strong {001}<0vw> fiber texture. The microstructure of hot rolled strips was composed of ferrite and pearlite and the microstructure was gradually refined with increasing hot rolling reduction. In the hot rolled strips, α and γ fiber textures were enhanced at the expense of initial {001}<0vw> fiber texture and Goss texture was generated in the surface and sub-surface layer with increasing hot rolling reduction. Besides, a great number of dispersed MnS particles with the size of 20-30nm were observed in the hot rolled strips. These MnS particles could act as the effective inhibitors during the second recrystallization annealing of the grain-oriented silicon steel.
Influence of Deposition Mode in Reactively Sputtered ZnO Underlayer on Thermal Stability of Thin Silver Films
Authors: Sun Yao , Wang Hong
Published: April 2016

The influence of deposition mode of the ZnO underlayer on the thermal stability of 20nm thick Ag films in the ZnO/Ag/SiN multilayer stacks were investigated. ZnO films were deposited by reactive sputtering of Zn target under different O2 flows corresponding to both transition and oxide modes. The films were characterized by sheet resistance, X-ray diffraction and SEM imaging before and after thermal annealing at 350°C, 400°C and 500°C, respectively. The results show that ZnO underlayer improves the thermal stability of the Ag films significantly. The ZnO deposition mode has huge impact on the Ag film on top of it. Compared with ZnO deposited in transition mode, ZnO deposited in oxide mode can induce more crystalline Ag film with stronger (111) preferred orientation, which is more thermally stable. For ZnO deposition in oxide mode, an optimal oxygen flow is identified to result in the most thermally stable Ag layer.
A Comparison of Diamond-Like Carbon Films Properties Obtained by Plasma Enhanced Chemical Vapor Deposition and Electro-Deposition
Authors: Wang Ning , Wang Jing , Zheng Fu Wei , Wu Yu Min , Hou Bao Rong
Published: April 2016

This paper compares the microstructure and electrochemical properties of the diamond-like carbon films obtained by two different deposition methods - microwave electron cyclotron resonance plasma enhanced chemical vapor deposition (MWECR-PECVD) techniques and electro-deposition – chosen for their low cost and capacity to produce films. The microstructure of the DLC films are investigated by Raman spectroscopy, FTIR spectroscopy, and electrochemical behavior is investigated by potentiodynamic and electrochemical impedance spectroscopy (EIS). Raman spectroscopy indicates that all the films deposited by different techniques show amorphous structure and typical characteristic of DLC film. FTIR spectrum results indicate that these DLC films are a-C:H films. As a result of EIS, the DLC films made by different methods showed obviously different electrochemical characters. The obtained results show that the DLC films deposited using the PECVD methods provided the better results, presenting a high corrosion resistance , high adherence to substrate, and a denser and more uniform surface.
Tribological Investigation of Guanidinium Ionic Liquids as Lubricants for Steel/Bronze Contacts
Authors: Yu Gui Qin , Yang Kuo , Liu Jian Jun , Liang Yong Min
Published: April 2016

Two kinds of guanidinium ionic liquids were synthesized. The thermal stabilities of the ionic liquids were evaluated by a hermogravimetric analyzer. Their tribological properties were investigated and compared with alkyl imidazole ionic liquids and liquid paraffin by SRV friction-wear test. The images of worn surfaces were observed under scanning electron microscope. X-ray photoelectron spectrometer analysis was carried out to explore the lubrication mechanism. The results showed that guanidinium ionic liquids were the best lubricants among the tested lubricants for steel/bronze contacts. Complex tribochemical reactions occurred during the sliding process and boundary lubrication films formed on the bronze/steel friction pair interface.
Millimeter Wave Absorbing Electromagnetic Properties of ZnO Whisker/Silicon Resin Coating Material
Authors: Xuan Xiong , Zhang Hai Yan , Zeng Guo Xun , Bo Ng Kung , Chan Chi Hou
Published: April 2016

Wave-absorbing coating samples are fabricated with ZnO whisker, the absorbent and silicon resin coating as the binder.The influences of the content of ZnO whisker in the absorbing coating and the thickness of the coating on millimeter wave absorbing property are analyzed.With the increasing of the thickness, the absorbing performance of the sample is enhanced significantly , the results show that with a ZnO whisker mass of 50% and coating thickness of 2 mm, excellent absorption (R<-10dB) is observed in the wave band from 66 to 78 GHz (with a bandwidth of 12GHz) . When the ZnO whisker mass is reduced to 30% with the same thickness of 2mm, two absorption bands are obtained from 55 to 67 GHz (with a bandwidth 12GHz) and 100 to 110 GHz (with a bandwidth 10GHz). Maxwell equations and boundary conditions are used to analyze the absorbing mechanism of the coating.
Preparation and Characterization of Boron Controlled-Release Film as a Potential Coating Material
Authors: Lin Bing , Zheng Cheng Zhang , Zhao Mei He , Wu Pei Qi , Gu Wen Xiang , Lu Qi Ming
Published: April 2016

The blend film is a favorable coating material for controlled-release fertilizer.The biodegradable PVA-boric acid controlled-release film and PVA-borax controlled-release film were prepared by the solution casting method.The water permeability and water absorbency were systematically investigated. The mechanical properties of these materials were determined with a strength-testing machine.The composite structure was determined by Fourier transform infrared (FTIR) spectroscopy and the scanning electron microscopy (SEM).The good controlled-release properties,lower water permeability and better tensile strength implied that the boron controlled-release film may be a potential coating material for the application in the controlled-release fertilizer.
Fabrication of Transparent Hydrophilic Nanosized TiO2 Films via Layer-by-Layer Self-Assembly
Authors: Zeng Zhi Yong , Shi Ying , Yuan Su Jun , Xie Jian Jun
Published: April 2016

The transparent nanosized TiO2 film was fabricated by a layer-by-layer assembly method starting from the highly dispersed anatase oppositely charged TiO2 nanoparticles without using anypoly electrolytes. The positively charged TiO2 nanoparticles (ca.7 nm) and negatively charged TiO2 nanoparticles (ca.7 nm) were synthesized by a subsequently hydrothermal process. Field-emission scanning electron microscopy, UV-vis transmittance spectra and Contact angle measurement were employed to characterize TiO2films.By the treatment of 500°C for 2hrs, the nanostructured TiO2 film showed a water contact angle of below 10°andthe relative transmittance to quartz glass of over 90%.
The Effect of Sintering Temperature on the Crystal Structure and Luminescence Properties of Pr:LSO Polycrystalline Films
Authors: Zhang Xiao Xin , Xie Jian Jun , Shi Ying , Fan Ling Cong , Lin De Bao , Chen Xu , Zhang Yu Yu
Published: April 2016

Lutetium oxyorthosilicate (Lu2SiO5, LSO) doped with Pr3+ was synthesized on cleaned silicon (111) substrates by sol-gel route with the spin-coating technique. XRD patterns indicated that the films were crystallized into A-type LSO phase at 1000 °C, followed by a phase transition to B-type LSO occurred at 1100 °C. SEM observations revealed that the surface of the films was smooth, homogeneous and crack-free. When the sintering temperature was 1000 °C, the average grain size of the crystal particles was 100-200 nm and the thickness of the thin film was about 380 nm when the coating layer number up to 10. While the sintering temperature was 1100 °C, the average grain size of the crystal particles was 200-300 nm and the thickness of the thin film was about 320 nm also 10 layers. PL spectra showed when under 1000 °C, the quenching concentration of Pr3+ was 0.3 mol%, the characteristic emission peaks was 289 nm and 340 nm and the dominant decay time was 4.64 ns; while under 1100 °C, the quenching concentration of Pr3+ was 0.4 mol%, the characteristic emission peaks was 280 nm and 320 nm and the dominant decay time was 2.61 ns.
Influence of Pulse Frequency on the Structure and Oxidation Resistance of AlPO4 Ceramics Coating and its Deposition Dynamics
Authors: Zhou Lei , Huang Jian Feng , Cao Li Yun , Li He Jun , Hao Wei , Ouyang Hai Bo
Published: April 2016

A facile pulse arc discharge deposition method was developed to prepare AlPO4 oxidation resistant outer coating on SiC pre-coated carbon/carbon composites (SiC-C/C). The deposition dynamics and the influence of pulse frequency on composition, microstructure and oxidation resistance of the as-prepared coating were investigated. Results show that pulse arc discharge deposition is an effective route to achieve dense and crack-free AlPO4 coatings. The deposition activation energy of the AlPO4 coating is calculated to be 3.07 kJ·mol-1. The AlPO4 coating prepared at a pulse frequency of 2000 Hz exhibits good oxidation resistance, which can effectively protect C/C composites from oxidation in air at 1773 K for 262 h with a weight loss of 1.58%.
Preparation and Photocatalytic Properties of Terrace Composite SnO2/TiO2:Cu2+ Film
Authors: Wang Guo Dong , Wei Chang Ping , He Rui Ying , San Jing , Peng Chun Jia
Published: April 2016

nanoSnO2 and Cu-doped TiO2 gelatins were prepared by sol-gel method, coated onto glass substrates by spin coating method, followed by drying at low temperature and calcined at high temperature, the influence on the structure and properties made by doping amount and composite form was discussed about. The films were characterized by XRD, SEM , EDS and UV-Vis, the photocatalysis degradation efficiency was studied as well. The results showed that the SnO2/ TiO2:Cu2+films were anatase structure, the surface were flat and stable without obvious crack, average diameter was about 20 nm. EDS indicated that Cu was introduced to TiO2 stratum of the SnO2TiO2 films ; UV-Vis showed the absorbance at visible region increased comparing to pure TiO2 and mixed SnO2TiO2 system. The degradation experiment under UV light showed degradation efficiency of SnO2/ TiO2: Cu2+films was higher compared with the mixed structure films, When the doping amount of Cu increased to 10% (mole fraction), the photocatalysis degradation efficiency reached its maximum.
Corrosion Behaviors of Fluoride Treated Cast Magnesium Alloy in Hank’s Solution
Authors: Zhang Chun Yan , Yang Ming Bo , Liu Cheng Long
Published: April 2016

Fluoride conversion films were synthesized on cast magnesium alloy AZ31 by immersion in hydrofluoric acid for different days to improve the corrosion resistance of Mg alloys as degradable implant material. The effects of the films on the corrosion behavior of the mg substrates were investigated by immersion tests. The results showed the fluoride conversion film was affected by the distribution of the chemical component of cast AZ31 alloy and the film on the second phases has more pores and micro-crack, but the bottoms of the pores were also covered by the conversion film and the substrate was not exposed through the pores. The fluoride conversion coatings significantly improved the corrosion resistance of cast AZ31 alloy. The film on the second phase with more pores is the first to dissolve. The most improved corrosion protection was achieved by 15 days treatment with the thickest film in terms of hydrogen evolution rate and damage morphology.
The Influence of C2H2 Flow Rate on the Composition, Structural and Properties of the Ni/α-C:H Films Deposited by FCVA
Authors: Zhou Han , Hou Qing Yan , Xiao Tian Qing , Liao Bin , Wu Xian Ying , Zhang Xu
Published: April 2016

Nickel/carbon nanocomposite films with different C2H2 flow rate were deposited by filtered cathodic vacuum arc (FCVA) device. The composition and nanostructure of the films were investigated by X-ray diffraction (XRD), Raman scattering spectroscopy, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The grain size increase from 8.7 nm at the C2H2 flow rate of 10 sccm to the maximum of 11.5 nm at 30 sccm, after that it decrease. The mean phase separation is in the range of 0.2-2.6 nm. The hardness of 21.6 Gpa was obtained at 50sccm.
Development of a Temperature and Pressure-Controlled Corrosion Test Vessel
Authors: Sun Li Juan , Wang Jia
Published: April 2016

Temperature and pressure are very important factors that influence corrosion process. We often need to choose a proper vessel in the corrosion test that need to control both temperature and pressure. Moreover, the material of the test vessel should not be harmful to corrosion liquid. For example, steel even stainless steel will be corroded in warm seawater, and they are not suitable for the vessel material. We designed a corrosion test vessel made of Poly-Propylene Random (PPR), and temperature can be controlled within room temperature and 100Celsius degree, pressure can be controlled within1to10atm.(1MPa). In this paper, temperature-controlled method and pressure-controlled method are described. Temperature and pressure characteristics are also analyzed and described. Shell structure, material and design are introduced. A series of typical corrosion tests were performed by using this corrosion test vessel.
Research on Mechanical and Corrosion Properties of Ti-Microalloyed Biomedical Cobalt-Based Alloy
Authors: Cao Ya Ting , Wang Feng , Ran Qing Xuan , Xu Yu Lai , Li Jun , Xiao Xue Shan
Published: April 2016

0.15 wt. % Ti-microalloyed Co-28.5Cr-5.9Mo-0.27C alloy has been developed by examining the effect of solution and aging treatment on microstructure, mechanical and corrosion properties. The results showed that elongation of the cast specimen were lower than 8%, while reached 18% after solution-treated at 1220 °C for 4 h. Phase transformation from austenite to martensite was observed after aging at 800°C and the amount of transformed martensite increased with aging time. Polarization tests of the samples after solution and aging treatment were carried out in physiological saline at 37 °C, which showed a stable passive film formed on the surface and no apparent pitting phenomenon occurred on the specimens, which indicated that heat treatment has not significant influence on the corrosion resistance of Co-Cr-Mo-0.27C-0.15Ti alloy.
Progress in Fractionation Processes of Lignocellulosic Biomass for Biorefinery: A Review
Authors: Jiang Lu Xia , Fang Sheng , Mao Jian Wei , Xie Jin Hai
Published: April 2016

Due to the awareness of fossil fuel depletion and global warming, biorefinery for production of biofuels and valuable platform chemicals from lignocellulosic biomass has attracted growing interest in the past decades. With the rising concept of comprehensive utilization of lignocellulosic biomass,fractionation processes are generally necessary prior to its subsequent conversion with aims to produce purified cellulose with specific recovery of hemicellulose and lignin. In this review, ionic liquids fractionation,steam explosion based fractionation,twin-screw extrusion and organosolv fractionation are described and their features and comparative performances are discussed.
PGA Fiber Reinforced Calcium Aluminate Cement for Orthopaedic Application
Authors: Tan Yan Ni , Yong Liu , He Xiang , Wang Wen , Duan Dong , Li Kai Yang , Li Hui Xia , Luo Lan Lan
Published: April 2016

Calcium aluminate cement (CAC) is a penitential candidate for bone replacements with good bioactivity but relative lower strength. In this study, biodegradable PGA fiber was incorporated into the CAC paste in order to improve the strength of the material. And MC3T3 cells were seeded on the surface of CAC and CAC/fiber to study their in vitro biocompatibility. The results indicate that the PGA fiber can improve the compressive strength of CAC without changing the crystalline phases and micromorphology. Calcium aluminate oxide hydrate, katoite and Gibbsite crystals were detected by XRD. Plate-like crystals can be observed under FESEM. The MC3T3 cells were attached well on both CAC and CAC/fiber composite, indicating their good in vitro biocompatibility. In summary, fiber reinforcement can be an effective way to improve the properties of calcium aluminate cement for orthopaedic application.
Research Progress in Cellulose Extraction, Modification and Application
Authors: Liu Chao , Tan Zhi , Li Hui Min , Xie Zhi Wei , Peng Jin Ping , Liang Mei Ling , Guo Jian Wei
Published: April 2016

As the fossil resource supply situation become more serious and the increasingly serious environment problems, the development of new carbon resource utilization has become an urgent task. Plant cellulose is the most abundant natural resource, which is renewable, nontoxic and degradable, has been paid much attrition by researchers of many countries. This paper reviews recent progress in plant cellulose extract and modification, especially in chemical modification of cellulose derivatives. And the article described cellulose modification technology about pretreatment. The applications of modified cellulose in the field of environmental protection, pharmaceutical, paint and other industries introduced as well. Finally, the current research hotspots of cellulose modification technology were prospected.
Analysis of Solvent Properties of Mandarin Oil
Authors: Li Mei , Li Zhi Qiang , Shao Wei
Published: April 2016

Mandarin oil distilled from orange peels of producing the four different regions in China was the compound for the major component 85% limonene, mandarin oil were extracted twice to ensure the purity of limonene, respectively. The spectrum test and Solvent solubility of chemical analysis indicate that it is a certain fluorescence effect and the ultraviolet absorption scope of peak is at 220~280nm, the capability to dissolve polyphenyl foam plastics replace benzene, methylbenzene and tetrachloroethylene by Mandarin oil, the results show that limonene is a safe, non-toxic organic solvent with high performance in chemical industry.
Preparation and Blood Compatibility of Multilayers on the Surface of Medical NiTi Alloy
Authors: Shao Hong Hong , Liu Xue Li , Zhu Zi Hong
Published: April 2016

In this paper, the TiO2 film and Ti/TiN/TiO2 multilayers were prepared by anodic oxidation and RF magnetron sputtering technology on surface of NiTi shape memory alloy, respectively. The structure and surface morphology of films were systematically studied by X ray diffracmeter (XRD) and scanning electron microscope (SEM); blood compatibility was researched by kinetic clotting time and platelets adsorption experiment. The result showed that, blood compatibility was improved in varying degrees after surface treatment. And the multilayer which was deposited on NiTi alloy by RF reactive magnetron sputtering after the method of constant voltage anodization had optimal Anti-clotting properties.
Preparation of Three Modified Natural Zeolite Powders and Antibacterial Properties of Antibacterial Paper Prepared Using them as Fillers
Authors: Yuan Lin , Qian Xue Ren
Published: April 2016

Natural zeolite powders, 600 meshes in size, were pretreated with three strong acids , then reacted with sodium chloride, sodium sulfate, sodium nitrate, respectively, and yielded sodium zeolite. The samples were loaded Ag++Zn2+, Ag++Cu2+, Zn2++Cu2+, and Ag++Cu2++Zn2+ ions through ion exchange to prepare the antibacterial zeolite powders. The powders were tested by MIC, SEM/EDXA and XRD. The results demonstrated that the pretreatment of zeolite powder with nitric acid could achieve a larger loading amount of metal ions compared to hydrochloric acid and sulfuric acid, and the samples loaded with Ag++Zn2+, Ag++Cu2+,Ag++Cu2++Zn2+ could attain excellent antibacterial properties with an MIC of 8 μg/ml to S. aureus Adding 5% of the aforementioned antibacterial zeolite powders to paper as filler resulted in an impressive antibacterial effect against S. aureus, as the inhibitory rate could reach to almost 100% in 1 h.
A New Solvent for the Industrial Production of Cellulose Fibers: Quaternary Ammonium Acetate
Authors: Miao Jiao Jiao , Yu Yong Qi , Zhang Li Ping
Published: April 2016

Tetrabutylammonium acetate, a new solvent, can dissolve cellulose (8 wt%) within 5 min at 40°C with dimethyl sulfoxide as coslovent without any pretreatment or inert gas atmosphere. The dissolution detail was recorded by Confocal Laser Scanning Microscope. And the viscosity of cellulose solution prepared from the new solvent was only 10% of that prepared from [BMIM]Cl. Moreover, the influence of molecular weight on the rheology of the cellulose solution was investigated. With the increase of the molecular weight, the viscosity was increasing and the cross-over point of the storage modulus (G′) and loss modulus (G′′) curves shifted to the lower angular frequency. The structure and mechanical properties of the fibers prepared from the cellulose solution were characterized by FT-IR, XRD, SEM and DSC. During the dissolution process, the crystalline region of the cellulose was destroyed and the celluloseIbecame amorphous. However, part of amorphous cellulose transformed into celluloseII by the wet spinning, indicated by FT-IR and XRD spectrum. SEM images showed that the resulting fibers were homogeneous with smooth surfaces and circular cross-sections. Meanwhile, the cellulose fibers had good thermal stability, measured by DSC. This work provided a promising way to prepare cellulose fibers with good physical properties, which was green, low cost and suitable for industrial production.
Preparation and Performance Characterization of Hemostatic Materials
Authors: Wang Feng Ming , Wei Chang Ping , Li Jing , Sun Shuang , Dong Li Dan , Liu Qing Yi
Published: April 2016

Nanometer chitosan (nmCS) was obtained by ion exchange methodology, and the nanometer CS-Ag、CS-Ca and CS-Ag-Ca were prepared by introducing AgNO3 and saturated CaCl2 solution into the product obtained above. The structures of samples were characterized by IR, XRD, SEM etc. The properties of cruor and hemostasis were studied by biological experiment. The results showed that the characteristic absorption peaks at 1647 cm-1 and 1560 cm-1 in the IR spectra of modified chitosan were assigned to nanometer chitosan sodium salt. The XRD spectra showed the characteristics of crystal shape of Ag+ and Ca2+. The SEM showed that nanometer chitosan had a part of precipitate of Ag+ and the composite effect of nanometer CS-Ca was better. The properties of cruor and hemostasis of CS-Ag-Ca were superior to CS-Ag and CS-Ca, while the CS-Ag and CS-Ca were also had an advantage over CS.
Optimal Design and Simulation for a Bio-Inspired Micromixer Based on Blood Transport in Vessel
Authors: Chen Xue Ye , He Yuan
Published: April 2016

A novel design concept for micromixer based on blood transport bionic principle has been presented. The bio-inspired micromixer based on blood transport in blood vessel is simulated to obtain a desired mixing efficiency. The flow rate, sample concentration distribution, channel width ratio, and channel arrangement as operating factors were researched to evaluate the mixing performance. The simulation results show the micromixer can give a high performance with the optimized simple structure. The bionic micromixer is proven to be effective for enhancing sample mixing and will have great potential to instruct design of micromixers.
Preparation, Corrosion and Cytocompatability In Vitro of Fluoride-Coated Mg-Zn-Zr Alloy
Authors: Zheng Hao Ran , Zhang Jing , You Chen , Chen Min Fang
Published: April 2016

The present investigation was carried out to optimize the hydrogen fluoride (HF) aqueous solution treatment for an Mg-2.5Zn-0.5Zr alloy, in order to improve the corrosion resistance of the material for orthopaedic applications. An MgF2 coating was formed on the surface of Mg-2.5Zn-0.5Zr alloy treated with HF solution. The effect of the HF concentration and processing time on the morphology and electrochemical performance of the MgF2 coating was systematically studied. The results showed that the MgF2 coating became thick gradually with the increase of the concentration of HF solution. However, the pinhole on the surface treated with 40% HF increased significantly. The coating thickness immersed in the same concentration of HF solution increased with immersion time, and cracks formed in the surface after four hours of immersion, resulting in a decrease in the corrosion potential. When the alloy was immersed in the HF solution with a concentration 20% at 37°C for 2h, a uniform and dense fluoride coating was formed, with a thickness of MgF2 layer of about 0.5μm. The corrosion potential of the coated Mg alloy in simulated body fluid (SBF) was 0.28V higher than the uncoated one. In addition, the fluoride-coated showed a good biocompatibility.
The Preparation and Characterization of Magnesium Oxide Whisker
Authors: Liu Bei , Zhao Yun , Jia Jun Ping , You Chen , Chen Min Fang
Published: April 2016

Due to the special topography in length and diameter, magnesium oxide (MgO) whisker has good mechanical properties to improve the mechanical and biological properties of biodegradable polymer materials, while the morphology of MgO whisker is significantly related to the morphology of its precursor whisker. In this work the precursor whisker is prepared through the mild solution approach and the effects of three producing factors on the growth of precursor whisker are systematically investigated by scanning electronic microscopy (SEM) and X-ray diffraction (XRD). It reveals that the morphology and composition of MgO predominantly dependent on precursor is prominently influenced by the preparing parameters, especially in solution concentration, aging time and aging temperature. The suitable preparing conditions in present experiment are with 0.6mol/L solution concentration, under 10h aging time and at room temperature, through which the radial dimension of whisker reaches to the nanolevel and the optimal aspect ratio is 80:1.
Three-Point Bending Shear Stress of Wooden Sandwich Composite
Authors: Wu Xin Feng , Xu Jian Ying , Hao Jing Xin , Liao Rui , Zhong Zhu
Published: April 2016

The effect of construction parameters and material type on bending shear stress and shear force was analyzed systematically. It is shown that maximum bending shear stress of sandwich construction is smaller than homogeneous single layer beam with same cross section if the skin has higher modulus than the core. Besides the effect of core or skin layer to shear force is almost identical for sandwich composite composed by different materials with same construction parameter. In addition, the shear force can be taken almost by the core of sandwich beam only if the ratio of core thickness to the whole is more than. Otherwise the resistance to shear force of skin layer should be considered to calculate the shear deformation. The results can provide basic theory for design optimization of sandwich construction.
Study on the Removal of Pb2+, Cu2+, and Cd2+ from Wastewater Using Modified Stilbite
Authors: Chen Xi , Cui Tian Shun , Zhao Shuang , Deng Xiao Jun
Published: April 2016

In this study, we studied the ability of modified Stilbite to adsorb heavy metals Pb2+, Cu2+, and Cd2+ from wastewater. In static conditions, we investigated the impact of pH, temperature, dosage, and the competitive adsorption characteristics of the modified Stilbite in addressing pollution of wastewater with Pb2+, Cu2+, Cd2+. The testing showed that: under normal circumstances, with a pH between 5-6, a dosage of 0.7 g, and an adsorption time of 90 minutes, the adsorption rate of the three metals was above 90%. The adsorption rate of Cu was greater than Pb, which was greater than Cd. The modified Stilbite adsorption of the three metals met Langmuir and Freundlich isothermal adsorption equations. The study also revealed that regenerated Stilbite, after adsorption, can still continue to be used for adsorption of heavy metals.
Effect of Supplementary Curing after Steam-Curing on Performance of Concrete
Authors: Li Xiao , Niu Wan Yang
Published: April 2016

When the low strength grade of steam-curing concrete is produced, the temperature which the concrete leaves steam-curing kiln is about 20°C commonly. The temperature difference is too large between the environmental temperature and the temperature which the concrete leaves steam-curing kiln when the daily average temperature drops to 10°C. Because the steam-curing concrete is cooled rapidly, a large of crack will be produced in concrete and the internal structure of concrete will be damaged normally. Then the performance of concrete will be influenced badly. In order to improve the negative effect on concrete by steam curing, the different supplementary curing is used after steam curing. The C30 concrete is made in this research. The daily average temperature is 5°C~10°C and the minimum temperature is-6°C during the test. After the concrete is formed, it is placed in 20°C environment for 2h first. Then the concrete is heated to 55°C in 2h and maintained for 8h in the steam-curing kiln. In the end, the concrete is cooled to 20°C in 3h. After steam curing, the standard curing and covering by wet fabric or film outside are used separately for concrete. The supplementary curing time is 1d, 2d, 3d and 4d. Then the concrete is placed in natural environment to 28d. The microstructure of hydration products are observed by electron microscope. The density of concrete is analyzed by the result of the 28d saturated water content, softening factor and 28d rapid carbonation depth. The mechanical properties of concrete are researched by the result of the 28d strength. When the concrete adopts standard curing or covering by film after steam-curing, the saturated water content and 28d rapid carbonation depth of the concrete will reduce, but the softening factor and 28d strength of the concrete will increase with the time. The performance of concrete which adopts covering by wet fabric after steam-curing is worse than that adopting standard curing. At the same time, the saturated water content and softening factor of concrete change little. Covering by wet fabric is worse than no covering or similar. In the test environment, the performance of the steam-curing concrete with each supplementary curing is worse than that of the concrete with standard curing. The standard curing is the best supplementary curing in this test. But covering by film is a worthy supplementary curing from economy and practicability. Covering by film for 4d, the 28d strength of steam-curing concrete is 87 percent of that of the concrete with standard curing and exceeds Design grade. Its saturated water content is 1.50% and softening factor is 0.932. Its rapid carbonation depth is close to that of the concrete with standard curing and its microstructure of hydration products is preferable.
Numerical and Experimental Investigation of Piezoresistance of Asphalt Concrete Containing Graphite
Authors: Tang Ning , Pan Wen Hao , Chen Yan Wen , Dai Min , Wang Qing
Published: April 2016

Asphalt concrete is an insulating material. Conductive materials are added to asphalt concrete in order that improving the conductivity. Conductive asphalt concrete (CAC) has become a promising method to snow melting and self-monitoring. In this study, the piezoresistance of CAC which can be improved the conductivity through graphite are analyzed. Based on the interparticle separation and bitumen film-thickness of graphite particle, a model has been developed to predict the piezoresistance under the applied stress. The influences of applied stress, graphite diameter, graphite volume fraction, compressive modulus on the piezoresistance are interpreted through laboratory experiments. Both the numerical and experimental results show that the theoretical data obtained from the model are found to agree with the experimental ones fairly well. In addition, it was found that all these parameters influence the piezoresistance by altering the change process of interparticle separation of graphite.
A Study on the Preparation of Epoxy - Modified Polyurethane Foam and its Adhesive Properties
Authors: Huang Hong Jun , Du Zhi Hong , Wang Jian Jiang , Wan Hong Jing , Wan Guo Shun , Ren Shui Yun , Zhong Hui
Published: April 2016

Epoxy resin (EP) modified polyurethane prepolymer (PUP) was prepared by synthesizing prepolymer method, and then EP/PU interpenetrating polymer networks (IPN) composites was produced with better adhesive properties as the foam expands further. The effects of the process on graft reaction and spatial structure of EP/PU IPN composites was studied by FT-IR and scanning electron microscopy (SEM). And a study on the adhesive properties of polyurethane foams with different content of epoxy resins was done by adhesion strength test. The adhesive strength of the IPNs composites were significantly improved when the EP content was 50%. The thermal stability and the expansion ratio of EP/PU IPNs composites were reduced slightly. The modified IPN composites were expected to be used as the preparation of high viscosity and high dilatability of the special - purpose materials in future.
Study on the Pore Size Distribution of the Bicomponent Spunbond Nonwoven Geotextiles
Authors: Zhang Heng , Qian Xiao Ming , Zhen Qi
Published: April 2016

Pore size plays a key role in the performances, such as transportation, filtration and separation, of bicomponentspunbond nonwoven geotextiles which fibrillated by hydroentanglement method. In this research work, samples of polyester (PET) - nylon6 (PA6) hollow segmented-pie bicomponentspunbond nonwoven materials were selected. A modified pore size prediction model has been proposed to predict the pore properties, and comparisons between theoretical and experimental results also discussed. The results show that the bicomponent fibers has been splitting into ultrafine fibers under the effect of the hydroentanglement method, and ultrafine fibers oriented mainly in the X-Y directions (plane direction). There is a good agreement between experimental results and experimental results, and the model of the pore size distribution is suit for the PET/PA6 bicomponentspunbond nonwoven geotextiles can be determined. The model provides a quantitative description of pore distribution for those nonwoven materials claimed to constitute with a series of types fiber.
Resistance of Straw-Geopolymer Materials to Acid and Alkali Attack
Authors: Jin Man Tong , Xia Rui Qi , Zhu Cong Ying , Zheng Yan Xia , Jin Zan Fang
Published: April 2016

Straw fibers reinforced geopolymer, a new type of metakaolin-based geopolymer, was synthesized in a specific formulation with rice straw fibers added. The straw-geopolymers were soaked in sulfuric acid solution at pH of 1.0, 3.0 and 5.0, respectively, and sodium hydroxide solution at pH of 9.0, 11.0 and 13.0, respectively. Compressive strengths and microstructural changes were studied. The results showed that after being immersed in acid solution at a pH of 1.0 or alkali solution at a pH of 13.0 for 28 days, the compressive strengths of the specimens decreased from 50.28 MPa to 28.90 MPa and 40.00 MPa, respectively. The best performance was observed when the specimens were soaked in sodium hydroxide solution at a pH of 9.0. Scaning electron microscope (SEM) analyses indicated that the lamellar structure of the straw-geopolymer was consistent with pure geopolymer. Cracks which led to a loss of strength were found in the specimens soaked in acid solution at pH of 1.0 and 3.0.
Preparation and Properties of High-Performance Concrete with Ceramic Coarse Aggregate
Authors: Wu Ben Ying , Zhou Xi Wu , Lu Jin Zhong
Published: April 2016

High-performance concrete was prepared by using ceramic waste as coarse aggregate. The influences of several factors, such as the contents of ceramic coarse aggregates, fly ashes and silica fumes, on the properties of concrete material were investigated. The results show that the compressive strength of semi-porcelain coarse aggregate concrete are slightly lower than that of natural concrete, and the splitting tensile strength and the ratio of compressive strength and splitting tensile strength is similar to the ones of natural concrete. After fly ash and silica fume mixed, the compressive strength, the splitting tensile strength and the resistance to water penetration of concrete with semi-porcelain coarse aggregate increase significantly with the increase of silica fume content which meet the requirements of high-performance concrete. Concrete with orcelain coarse aggregate is only suitable for low strength concrete.
Progress in BiVO4 Photocatalyst under Visible Light
Authors: Yan Xue Lian , Chen Yuan , Liu Bi Tao , Tu Ming Jing
Published: April 2016

In recent years, as a novel photocatalyst with the excellent ability to absorb visible light, BiVO4 has drawn increasing attention. In this paper, the photocatalytic mechanism and the electronic band structure of BiVO4 were introduced in detail. On the basis of main modifications of BiVO4, progress in BiVO4 photocatalyst for degradation was further reviewed. The aim of this work is to provide guideline for the intensive studies of BiVO4 in future.
Modulus Parameter Analysis and Calculation of Steel Deck Asphalt Pavement Material
Authors: Wang Min , Liang Nai Xing , Xiao Li , Lan Chao
Published: April 2016

The numerical analysis model and analytic formula, concerning flexural-tensile composite modulus of steel deck paving materials, were established with five-point loading composite beams, in order to explore the modulus value of steel deck paving materials. Regarding the three typical asphalt pavement material such as SMA10, GA10 and EA10, the composite modulus of paving material was calculated by analyzing stepwise loading data, and a universal flexural-tensile composite modulus range is proposed: SMA10 is 500 ~ 550MPa, GA10 is 500 ~ 600MPa, EA10 is 650 ~ 700MPa. The results show good agreement between the modulus of the numerical analysis method and analytical formula method. The proposed analytical formulas can calculate the flexural-tensile composite modulus more easily according to the actual load conditions, and the modulus value played a significant role in guiding the design and mechanical analysis of steel deck pavement system.
Facile Synthesis of Phosphogypsum-Based Whiskers by Low Temperature Hydrothermal Route with CTAB Addition
Authors: Zhuang Lin Lin , Ding Ming , Han Cheng Liang
Published: April 2016

CaSO4·0.5H2O whiskers were successfully synthesized by hydrothermal process, in which phosphogypsum (PG) was employed as precursors. The effect of the hexadecyltrimethylammonium bromide (CTAB) on the formation of phosphogypsum-based CaSO4·0.5H2O whiskers was investigated in details. Results indicated that the average diameter and length of as-prepared CaSO4·0.5H2O whiskers with rough surface were about 0.15-2.5μm and 10-50 μm, respectively. The added CTAB templates would effectively guided the selective growth of CaSO4·0.5H2O particles which led to formation of whiskers with high aspect ratios.
Low-Cost Preparation of SBA-15 Silica Molecular Sieve and High Humidity Sensing Property in a Wide Range of Relative Humidity
Authors: Zhang Jie , Zhu Yong Heng , Kang Shi Zao , Li Xiang Qing , Xu Jia Qiang
Published: April 2016

In this paper, different SBA-15 molecular sieves were prepared in a facile sol-gel method by using a low-cost sodium silicate as silicon source at different ripening temperature. The materials were characterized by small-angle XRD, TEM, nitrogen adsorption–desorption test. The results showed that ripening temperature can affect the pore size and mesostructure of SBA-15. High surface area SBA-15 can be obtained at low ripening temperature, and plugged mesostructure can be prepared at high temperature. The gravimetric humidity sensing property of the materials were tested based on a transducer of quartz crystal microbalance. The test results revealed that all the samples showed high response in the wide range of relative humidity. The sensors based on that prepared at 35°C show a good stability and linearity in the range of 11.3%RH to 98%RRH along with fast response (12s) and recovery time (8s), ultrahigh sensitivity and low hysteresis, implying that has a great potential for humidity detection.
Study on the Drying Shrinkage Property of Magnesium Phosphate Cement
Authors: Qi Zhao Qing , Wang Hong Tao , Ding Jian Hua , Zhang Shi Hao
Published: April 2016

The influence of magnesium to phosphate weight ratios (M/P ratio), borax content, water to cement ratio (w/c ratio), fly ash, slag on magnesium phosphate cement of drying shrinkage is examined.The results show that the drying shrinkage of magnesium phosphate cementcan be affected at some extent by M/P ratio, w/c ratio,boraxcontent. Both the former two factors and the effects are significant.It was found that the drying shrinkage of magnesium phosphate cement decrease with the increase of M/P ratio,borax content, w/c ratio. If the 10%, 15% offly ashinstead of magnesium phosphate cement was added, drying shrinkage rate decreases with increases of dosage fly ash. When the 15% of magnesium phosphate cement is replaced by fly ash, the shrinkage rate of hydration 20d reachs11.2×10-5. When the 10% of magnesium phosphate cementis replaced by slag, the drying shrinkage rate reducedto 87.6%.comparing to the bench mark ,the drying shrinkage rate of 20d is only 2.78×10-5.
Fabrication of Ultra Low-Density Binderless Sandwiching Materials by Rapid Steam Injection
Authors: Cheng Fan , Jiang Yu Hao , Chen Jin Bo , Lu Peng Bo , Su Ling Feng , Yu Fan Zhe , Liu De Tao
Published: April 2016

Eco-friendly building materials with perfect thermal insulation & sound absorption property have become intriguing and eye-catching in recent years. In this work, the ultra low-density binderless sandwiching materials were firstly fabricated with ultra low-density of 60-80 kg/m3 by self-designed rapid steam injection technology. The main experimental factor of density, holding time, transmission time, steam injection pressure and fiber’s dimension was respectively investigated to their effects on formation of the new building materials. IR, Py GC-MS and AFM analysis were performed to study the mechanism of binderless sandwiching materials under steam injection process. The bending strength, thermal insulation & sound absorption property of the new materials were also studied. This new building material with no resin use and no formaldehyde release is expected to be reserved as the sandwich for designing thermal insulation & noise reduction building materials.
Preparation of SnO2-TiO2/Zeolite Y Composites with Enhanced Photocatalytic Activity
Authors: Yang Jing , Xu Xiao Wen
Published: April 2016

SnO2-TiO2/zeolite Y composites were prepared by the impregnation of tin chloride and tetrabutyl titanate solution with zeolite Y and subsequent calcination at 500. SnO2-TiO2 heterostructures coated on zeolite Y is ascertained by X-ray diffraction, high-resolution transmission electron microscopy and UV-vis diffuse reflectance spectra characterization. The photocatalytic studies suggested that the SnO2-TiO2/zeolite Y showed enhanced photocatalytic efficiency of photodegradation of methyl orange compared with TiO2/ zeolite Y and SnO2/zeolite Y under UV light irradiation.
Structure-Performance Correlations in Electrochromic Behaviors of Terpyridine-Metal Hybrid Materials
Authors: Yang Jia Wei , Xie Xian Ge , Wang Xiao Mei , Ye Chang Qing , Zhou Yu Yang
Published: April 2016

Exploring the structure-property relationships is a fundamental but significant work for the design of new molecular. Rationaly designing of electrochromic materials that can switch rapidly and durably requires sophisticated understanding of the correlations between molecular structure and the performance. This work presents four electro-polymerizable metallosupramolecular coordinations self-assembled from triphenylamine-based terpyridine ligands and metal ions (Fe2+, Ru2+). The polymerized metal complexes can exhibit reversible change of the metal-to-ligand charge transfer (MLCT) absorption intensity. Along with the increase of voltage, the intensity of MLCT absorption peaks gradually reduced to disappear. Structure/performance correlations in electrochromic performance, especially the influence of different ligands and metal ions upon the coloration efficiency have been discussed.
Influence of DC Bias on the Properties of the Piezoelectric Material
Authors: Le Kang , Feng Yu Jun
Published: April 2016

According to the resonant characteristics of piezoelectric materials, in order to get the parameters of piezoelectric materials under DC bias voltage by calculate the impedance spectrum of piezoelectric materials, and the changes of the parameters of piezoelectric materials under DC bias were discussed. This paper measured the impedance spectrum of piezoelectric materials under different DC bias voltage with TH2828S Impedance Analyzer, and found that DC bias voltage made the material impedance spectrum drifted. Various parameters of materials were calculated by the resonance method, it was found that the parameters of piezoelectric materials under varied bias voltage were different, and the behaviours of each parameters under DC bias voltage were obtained.It was consider that the elastic constant and dielectric constant were changed due to the inverse piezoelectric effect of the piezoelectric materials which were under DC bias voltage,so that other parameters were changed.Then the resonant frequent formula of piezoelectric materials under DC bias voltage was deduced.
Low-Temperature Annealing on Treated of Pulsating Magnetic Field Fe-Co-M-B-Cu Amorphous
Authors: Zhang Yan Hui , Chao Yue Sheng , Jin Ying
Published: April 2016

After the medium-frequency magnetic pulse treating (frequency 1500-2000Hz, field intensity 200-250Oe) on amorphous Fe (Co)-M-B-Cu alloys, the vacuum anealing at low-temperature were in progress at 50°C-100°C for 30 min and 60 min. The soft magnetic properties of nanocrystalline alloy obtained by above mentioned treatments were measured by the vibrational specimen magnetometer. The results show that the structral relaxation , free volume migration and annihilation during the vacuum annealing will lead to the reduction of like-vacancy defects concentration and distortion stress. So the soft magnetic properties of nanocrystalline alloy will be improved further.