bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of palladium on the optical and hydrogen sensing characteristics of Pd-doped ZnO nanoparticles
Authors: Do Anh-Thu Thi , Giang Hong Thai , Do Thu Thi , Pham Ngan Quang , Ho Giang Truong
Published: August 2014

The effect of palladium doping of zinc oxide nanoparticles on the photoluminescence (PL) properties and hydrogen sensing characteristics of gas sensors is investigated. The PL intensity shows that the carrier dynamics coincides with the buildup of the Pd-related green emission. The comparison between the deep level emission and the gas sensing response characteristics allows us to suggest that the dissociation of hydrogen takes place at PdZn-vacancies ([Pd 2+(4d9)]). The design of this sensor allows for a continuous monitoring in the range of 0–100% LEL H2 concentration with high sensitivity and selectivity.
« Dis-moi ce que tu manges et je te dirai qui tu es ! ». Approche sémiotique des représentations mentales des marques alimentaires
Authors: Kessous Aurélie , Chalamon Isabelle
Published: August 2014

L’objet de cet article est de mieux comprendre comment utiliser les représentations mentales du « bon » et du « mauvais » dans le management des marques alimentaires. Pour ce faire, nous présentons d’une part, une classification de 4 types de produits : (1- produits authentiques et naturels, 2- produits d’excès et de transgression, 3- produits diététiques et fonctionnels, 4- produits pratico-économiques) sur laquelle se superposent 4 profils de consommateurs (1- authentiques, 2- transgressifs, 3- diététiques et 4- économes). Nous mettons en évidence d’autre part, les implications des représentations mentales du « bon » et du « mauvais » en matière de management des marques alimentaires. Cette étude repose sur des entretiens individuels de 20 consommateurs qui constituent le corpus d’une analyse sémiotique.
La fonction Achats de demain : analyse prospective par la méthode PM
Authors: Trehan Natacha
Published: August 2014

L’article présente les résultats d’une recherche prospective sur la fonction Achats par la méthode PM avec 42 acteurs-experts. Il ressort que les missions Achat de demain sont la création de valeur, la contribution à la réinvention du business model de l’entreprise, alors que le pouvoir s’inverse en faveur des fournisseurs clés. L’acheteur pilote de ces évolutions est nommé « mutant noétique ».
Heat-killed probiotic bacteria differentially regulate colonic epithelial cell production of human β-defensin-2: dependence on inflammatory cytokines
Authors: Habil N. , Abate W. , Beal J. , Foey A.D.
Published: August 2014

The inducible antimicrobial peptide human β-defensin-2 (hBD-2) stimulated by pro-inflammatory cytokines and bacterial products is essential to antipathogen responses of gut epithelial cells. Commensal and probiotic bacteria can augment such mucosal defences. Probiotic use in the treatment of inflammatory bowel disease, however, may have adverse effects, boosting inflammatory responses. The aim of this investigation was to determine the effect of selected probiotic strains on hBD-2 production by epithelial cells induced by pathologically relevant pro-inflammatory cytokines and the role of cytokine modulators in controlling hBD-2. Caco-2 colonic intestinal epithelial cells were pre-incubated with heat-killed probiotics, i.e. Lactobacillus casei strain Shirota (LcS) or Lactobacillus fermentum strain MS15 (LF), followed by stimulation of hBD-2 by interleukin (IL)-1β and tumour necrosis factor alpha (TNF-α) in the absence or presence of exogenous IL-10 or anti-IL-10 neutralising antibody. Cytokines and hBD-2 mRNA and protein were analysed by real-time quantitative polymerase chain reaction and enzyme-linked immunosorbent assay. LcS augmented IL-1β-induced hBD-2, whereas LF enhanced TNF-α- and suppressed IL-1β-induced hBD-2. LF enhanced TNF-α-induced TNF-α and suppressed IL-10, whereas augmented IL-1β-induced IL-10. LcS upregulated IL-1β-induced TNF-α mRNA and suppressed IL-10. Endogenous IL-10 differentially regulated hBD-2; neutralisation of IL-10 augmented TNF-α- and suppressed IL-1β-induced hBD-2. Exogenous IL-10, however, suppressed both TNF-α- and IL-1β-induced hBD-2; LcS partially rescued suppression in TNF-α- and IL-1β-stimulation, whereas LF further suppressed IL-1β-induced hBD-2. It can be concluded that probiotic strains differentially regulate hBD-2 mRNA expression and protein secretion, modulation being dictated by inflammatory stimulus and resulting cytokine environment.
Future Trends in Spectrum Management and Technology Choices for Broadband Aeronautical Communications
Authors: Curran Stephen John
Published: August 2014

The aircraft of the future will have an increased need for airborne communications among aircraft and between aircraft and the ground. Communications will include traffic such as on board passenger generated internet traffic, aircraft telemetry and information on air traffic control and weather. The likely data requirements are such that the data generated by passengers will be far greater than the aircraft generated data traffic. Passengers will expect data service on the aircraft similar to what they typically experience on the ground. Multimedia activities such video streaming are very bandwidth intensive and the provision of these services presents a serious technical challenge. On the ground, fibre optic cables are the method of choice for the provision of high speed data service and in contrast an airborne high speed data communications solution will need to be a wireless one.
2025
Authors: Fain Stacie L.
Published: August 2014

Several governmental entities: the Secretary of Transportation; the Departments of Defense, Homeland Security, and Commerce; the Federal Aviation Administration (FAA); National Aeronautics and Space Administration (NASA); and industry, aligned their resources to develop the Next Generation Air Transportation System (NextGen), a new approach to safety at airports in the United States (U.S.). NextGen places the responsibility for safety within airport management and changing the FAA's role from testing, inspecting, and certifying to approval and periodic audits of the Safety Management Systems (SMS) programs at U.S. airports. The purpose of the research was to determine, through a comprehensive literature review and evaluation, whether SMS will be used as the framework for U.S. airports to move safely into the year 2025. The researcher concluded that the vision for SMS implementation was well defined and the requirements fairly clear, but guidance and support for SMS implementation at U.S. airports are lacking.
Risk Management in Aviation
Authors: Smith Kevin M.
Published: August 2014

This relatively short article will set the stage for productive discussions concerning the effective management of risk in large scale dynamic systems, for which future articles will be featured. One of the most important first steps in this regard is the pressing need to understand the operational nature of risk and a rising risk profile. Much about risk is at once poorly understood and treated often as a one-off event instead as a cluster of risk management issues to be addressed from the standpoint of convergent technology applications, and performance modeling. A clear distinction by what is meant by low risk, moderate risk, and high risk needs to be developed. This the author will attempt to do here. Once an unambiguous demarcation line between Low, moderate, and high risk is made then the author will be able to proceed to the next important step in their conceptual development, and that is the specification of the decision analytical structure for all Operational Decisions.
A Simulation Approach to Enhancing Aircraft Availability
Authors: Bazargan Massoud , Byrnes Ken , Mazhar Ali , Adewumi Adedoyin , Liu Qing
Published: August 2014

This study presents a simulation approach to evaluate a potential strategy for dispatching aircraft at Embry – Riddle Aeronautical University. The current method of assigning aircraft to students is based on the highest utilization. A new strategy is proposed where the maintenance time is also incorporated into the aircraft utilization. Various performance measures such as aircraft availability, number of cancellations due to unavailability of aircraft, maintenance manpower and number of aircraft at maintenance hangar are examined under both methods. The analysis of the two methods suggests that changing the priority method in aircraft dispatch does not produce significant change in the system. Although both models are similar, the large deviations and variations in the proposed dispatch method discourage it from being implemented in its current form.
Broadband Communications for Aircraft in Oceanic and Other Remote Areas
Authors: Curran Stephen John
Published: August 2014

Data communication with aircraft presents unique technical challenges and these challenges are more pronounced when the aircraft are travelling over oceanic or other remote areas. When in populated areas, systems are available that can support high speed data services, one Gigabit per second (Gbps) and beyond via, terrestrial ground stations. However no such systems exist to provide airborne communications with high bandwidths among aircraft and between aircraft and the ground in more remote regions. Passengers will expect data service on the aircraft similar to what they typically experience on the ground. Multimedia activities, such as video streaming, are very bandwidth intensive and the provision of these services presents a serious technical challenge. On the ground, fibre optic cables are the method of choice for the provision of high speed data service, and in contrast, an airborne high speed data communications solution will need to be a wireless one.
Report and Commentary on the Go-Around Safety Forum
Authors: Smith Kevin M.
Published: August 2014

The principal investigator of the Go-Around Safety Forum and its report was Mr. Blajev Tzvetomir; EUROCONTROL. This report describes the background, purpose and objective of this important forum which was initiated by the Flight Safety Foundation, the European Regions Airline Association, and EUROCONTROL. The forum took place on 18 June 2013 in EUROCONTROL Brussels. The purpose of the forum was to address the growing concerns with the dramatic increase in “approach and landing” accidents. The Go-Around Safety Forum was initiated to support the flight safety foundations Go-Around safety initiative and to help the early implementation of actions for the European Action Plan for the prevention of Runway Excursions (EAPPRE), issued in January 2013. The operational problem as stated in the Forum's report and in various articles in Aviation Week & Space Technology (March 24th, 2014) is the growing number of approach and landing accidents and incidents. Indeed, ICAO reports that there about two runway excursions per week worldwide. Approach and landing accidents account for 62% of all accidents with indications that this trend will continue if decisive action is not taken.
Study of CSF in China's B2C E-Commerce Based on Expert Evaluation
Authors: Ke Xinsheng , Sun Qi
Published: August 2014

E-commerce changed the habits of the customers in recent 10 years. Analyzing the changes in customer's demand and the characteristics of e-commerce in China more and more companies commit to the war online. Making scientific quantitative analysis on the factors to each other, the quantitative index system provides a broad prospect for development. What's more, in order to solve the implementation of China's B2C e-commerce, the problem that is badly in need of solving in more fierce market competition currently. Based on the expert evaluation, this paper puts forward the critical factors in China's B2C e-commerce system, using numerical method to construct ISM, so that the CSFs can be got,namely it will be easier for the decision makers to catch the important points during the process.At last the instance of Jingdogn can be the perfect model for the strategies and the CSFs in practice.
A Personalized Recommendation Model in E Commerce Based on TOPSIS Algorithm
Authors: Wang Liang , Zhang Runtong , Ruan Huan
Published: August 2014

From the perspective of performance and universality, this paper analyzed the characteristics of typical technologies for personalized recommendation system, and then made a basic architecture for the improved model. With the architecture, this paper introduced a personalized recommendation model in e-commerce system. The model is based on an n-tiers structure and the TOPSIS algorithm, first standardize the user evaluation indexes, and then determine the indexes weights according to user's needs, and finally calculate the personalized recommendation results. This model can be applied to a variety of e-commerce applications, especially for the e-commerce application with structured or semi-structured products such as digital books, journals and other publications.
Constitutive Relationship Model of Al-W Alloy Using Artificial Neural Network
Authors: Guo La Feng , Li Bao Cheng , Xue Yong , Zhang Zhi Min
Published: August 2014

Isothermal compression experiment of Al-W alloy was carried out using Gleeble1500 thermodynamic simulator within a temperature range of 420°C-570°C and a strain rate range of 0.001s-1-1s-1。And the constitutive relationship model for this alloy was successfully developed using BP neural network. In the proposed model, the input variables are strain, strain rate and deformation temperature while the flow stress is the output variable. The results show that absolute maximum error between predicted and experimental values of flow stress is less than 10.0Mpa, the correlation coefficient is 0.993. It was found that the established constitutive relationship model could provide a good representation of the test data and describe the whole deforming process better compared with the traditional method.
Cracking Analysis of Automobile Rim Flash Butt Welding
Authors: Yin Na , Meng Xian Tang , Li Fei , Cui Yang , Zhou Zhi Wei
Published: August 2014

Aiming at the serious crack phenomenon of automobile rim butt welding in a domestic wheel plant, means of analysis such as chemical analysis, tensile test, bending test, macrocosmic and microcosmic examination were used to find out the formation mechanism. Results showed that the chemical compositions and mechanical properties of base metal near the weld fracture meet the quality requirements, while the widmanstaten structure and composite oxide inclusion covered in unmelted region, which could cause micro-cracks in the welded seam and lower the plasticity of welding seam, were the key reasons to cause cracks of welding.
Corrosion Behaviour of AZ91DSm1.0 with Different Preparation Methods
Authors: Liu Hong Xia , Liang Jin , Zhang Jue , Zhang Xiao Lian
Published: August 2014

Corrosion behaviour of AZ91DSm1.0 with different preparation methods(vacuum melting and common melting) is investigated. X-ray diffraction(XRD), optical microscopy(OM), scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS), corrosion weightless experiment and the potentiodynamic polarization curve are applied to characterize the corrosion behaviour. Results show that vacuum melting alloy possess higher corrosion resistance than common melting alloy. This is attributed to the rod-shaped Al3Sm which was formed in common melting alloy will have certain fragmentation effect on matrix that can lead to defects.
Fabrication of the Sheet-Metal Part with Non-Horizontal End Face Based on the CNC Incremental Forming
Authors: Zhu Hu , Liu Yi Bo , Ju Jin
Published: August 2014

Aiming at the problem that current CNC incremental forming technology can’t directly manufacture the sheet-metal part with non-horizontal end face, the method that can manufacture this kind of sheet-metal part by using the equidistant tool path parallel to the sheet metal was proposed in this paper, in which the support and sheet metal was made together and sheet metal was directly fixed on the support. In addition, the equidistant tool path parallel to the sheet metal was generated using UG software and the sheet-metal part was fabricated by using vertical CNC machining center.
Microstructure Evolution and Mechanical Properties of an Al-Cu-Mg Alloy at Elevated Temperature
Authors: Hao Min , Ru Ji Gang , Liu Ming , Zhang Kun , Wang Liang , Feng Zhao Hui
Published: August 2014

Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were utilized to study the microstructure and mechanical behavior of an Al-Cu-Mg alloy after tensile test at 125°C, 150°C, 175°C and 200 °C, respectively. The yield strength and ultimate tensile strength decreased with the increase of temperature, while the elongation increased firstly and then decreased. The S and S′ precipitate after tension at elevated temperatures. When the temperature was higher than 175°C, the precipitate coarsens rapidly. The alloys displayed a shear fracture features at elevated temperature. The larger S′ and S phase coarsened and dropped which forming crack in the grain boundaries and precipitate interfaces, resulting in the decrease of the elongation of the alloy.
Microstructure Evolution of Zn-Al Cladding Fabricated on AZ31 Magnesium Alloy
Authors: Sun An , Sui Xiao Ming , Li Hai Tao , Wang Qiang
Published: August 2014

The surface of AZ31 magnesium substrate is coated by Zn-Al alloys using cast-penetrated cladding. The transverse section of alloy cladding is composed of cladding zone, diffusional zone, and bonding zone. The microstructure evolution, phase constitution, and chemical composition of the transition layer are studied. The experimental results exhibit cladding zone contained dendrite matrix and interdendritic eutectic structures. The plume eutectic structure and columnar eutectic structure are formed in diffusional zone and bonding zone, respectively. Zn and Al solid solutions gradually decrease and disappear owing to the diffusion of magnesium atom and the changes of magnesium element concentration. Mg7Zn3 phases are generated rapidly due to the interdiffusion of zinc and magnesium atoms rapidly in the diffusional zone and bonding zone. As Mg-Zn eutectic phases hinder the movement of Mg and Al atoms, the Mg-Al intermetallic compounds are eliminated completely. The microstructure is transformed into Mg solid solution and Mg7Zn3 eutectic structure to combine with AZ31 base metal.
Effect of RE on Microstructure and Properties of AM60 Magnesium Alloy
Authors: Li Yao , Yang Jun Jie , Xue Ping , Zuo Z.J.
Published: August 2014

Industrial AM60 magnesium alloy, to which mixed rare earth containing Y, Gd and Nd elements is added, was used to study the effects of rare earth (RE) on their casting microstructures and properties. The experimental results showed that RE could effectively improve grain refinement and the internal organization, which transferred the Mg17Al12 phase from the network structure into grainy one. The microscopic analysis indicated that by adding the mixed RE, the amount of Mg17Al12 compounds was less than that without mixed RE on the grain boundaries, and it was replaced by Al-RE compounds. In addition, the mechanical properties of the alloy with mixed RE had been significantly improved and the maximum tensile strength was up to about 260MPa and the elongation rate could reach more than 10%. When the mixed RE content was more than 2%, coarse Al-RE compounds were formed in the alloy, which degraded the mechanical properties.
High Silicon Addition in 780 MPa Cold-Rolled Dual Phase Steel for Carbon Reduction and Plastic Reinforce
Authors: Kuang Shuang , Qi Xiu Mei
Published: August 2014

Two types of DP steels which contain high carbon and high silicon respectively were produced on industrial production line. The microstructures and mechanical properties were investigated. Based on the thermodynamics and kinetic analyses, the intercritical austenization was researched. The results show that the high silicon and low carbon composition used to DP steel can avoid martensite band structure and decrease the martensite fraction, which will improve the elongation and work hardening ability. Phase transformation kinetic analysis indicates that high silicon content can make manganese enrich in austenite and stabilize austenite in intercritical region. Assisted by the strengthening role of silicon in austenite, the mechanical properties of high silicon and low carbon DP can fully meet the standard.
Thermal and Oxidative Stability Thermosets Derived from Hybrids of Cyclosilazanes and Silicon-Containing Polyarylacetylene
Authors: Hu Qian , Qi Hui Min , Wang Fan , Zhu Ya Ping
Published: August 2014

Oxidative stable hybrid thermosets derived from silicon-containing polyarylacetylene (PSA-V) and branched methylvinylcyclosilazane (b-MVSZ) have been prepared, and b-MVSZ was synthesized by coammonolysis reaction of methylvinyldichlorosilane and vinyltrichlorosilane, which was characterized by using GC-MS, FT-IR, 1H NMR and GPC. The cure behaviors of PSA-V/b-MVSZ hybrids were investigated by DSC and the thermal and oxidative stabilities of the cured PSA-V/b-MVSZ hybrids were determined by TGA under nitrogen and air atmosphere. The results indicated that the PSA-V/b-MVSZ hybrids could be thermally cross-linked through the vinyl/ethynyl groups to form polymer networks. The cured PSA-V/b-MVSZ hybrids possessed high thermal stability, and with increasing the content of b-MVSZ, the thermooxidative stability of the hybrid materials was enhanced.
A High-Efficiency Inflame Retardant Modification of Poly(Ethylene Terephthalate)(PET) Fabric
Authors: Xu Fang , Zhang Feng Xiu , Zhang Gang Xian , Zhang Yuan Song
Published: August 2014

In this paper, the flame retardant HAS was applied to imparting flame retardance to polyester fabric. The result showed that the flame retardance of polyester fabric improved a lot. The limiting oxygen index increased while the concentration of HAS solution and temperature increased. Whiteness and elastic recovery angle decreased while the concentration of HAS solution increased. Found a good match to the concentration and temperature, the limiting oxygen index could increase to 29% while whiteness and elastic recovery angle kept well.
Experimental Study of the Strain in Different Structures of the InGaN/GaN and InGaN/AlInGaN Quantum Well
Authors: Liao Hui , Sun Mao Zhu , Zhang Jian Jun , Song Chun Yan , Fan Ting , Yang Kun
Published: August 2014

The strain existed in different quantum well structures was analyzed by XRD. By Omega/2Theta scanning,we got the satellite peaks of different samples. Analysis of the samples of these two quantum well about the level strain, vertical strain and the Quartet distortion. By Contrasting the ternary InGaN / GaN MQW samples with the quaternary InGaN/AlInGaN MQW samples,found that the level strain, vertical strain and the quartet distortion of ternary MQW samples are higher than the InGaN / AlInGaN quantum well samples about 0.03%, 0.09 % and 0.12% respectively. Analysis shows that the InGaN/AlInGaN quantum well structure can be better to release their internal stress.
Yellow Luminescence Iridium Complex and its Composite with Polymers
Authors: Lin Mei Juan , Zeng Hui Juan , Tang Qiang , Ling Qi Dan
Published: August 2014

Yellow light-emitting heteroleptic iridium complex with 2-(4-bromophenyl) -1H-benzo [d] imidazole as cylcometalated ligand and 5,5'-dimethyl-2,2'-dipyridyl as the ancillary ligand was synthesized and characterized by 1H NMR, elemental analysis and IR. The poly (methyl methacrylate)(PMMA) and poly (ethyl acrylate carbazole)(PEAK) doped with the complex were prepared by solution method. The photoluminescent properties of the complex and polymers were studied. The results show that the complex exhibits yellow luminescence with the emission peak of 562nm and CIE coordinates of (0.439, 0.502) upon 365nm excitation. The polymers transfer effectively intermolecular energy to the iridium complex, which results in effective yellow emission for the doped polymers.
Photoelectric Properties of High Power GaN Based LEDs on Cu/Cr Composite Substrates
Authors: Xiao Zonghu
Published: August 2014

The thermal problems of high power LEDs could be solved effectively and the stability of the device could be also improved, employing metal substrates for high power LEDs. In this paper,high power GaN based blue LEDs on metal substrates were successfully prepared by transferring GaN-based LED epitaxial film on Si (111) substrates to the Cu/Cr composite substrates employing electroplating method. The forward voltage of the as-prepared LEDs was 3.4 V, when the forward operating current was 350 mA, which was similar with the level of market products. The corresponding voltage could reach 25 V when reverse current was 10 μA, better than the level of market products. It showed good anti-saturation property when forward current varied from 0 mA to 1200 mA. The stability of wavelength vs current was also favourable, which the peak wavelength shifted to long wavelength about 1nm in the test range of 10 mA to 1200 mA.
Shape-Controlled Synthesis of Ag Nanocubes with Uniform Size
Authors: Zhao Yu Xia , Liu Cheng Mei , Han Lu , Wei Yen
Published: August 2014

The controllable synthesis of special shape of nanoparticles with uniform size was most important for some special applications. In this work, we prepared silver nanocubes by Na2S-mediated polyol synthesis using AgNO3 as precursor, polyvinyl pyrrolidine(PVP) as capping agent and ethylene glycol(EG) as solvent and reductant under the protection of Ar characterized by SEM, UV-vis, DLS and Zeta potential. Silver nanocubes were successfully controllably obtained via optimizing the reaction conditions, such as the rate of Ar initially after 50 min pre-heating and subsequently after the addition of AgNO3 solution，the volume of 3 mM Na2S solution. The results showed that silver nanocubes with edge length of 50 nm and sharp corners were achieved at 230μL 3mM Na2S solution added under a Ar rate of 1000 ml/min.
Resistivity Characterization of Ti Based ATO and its Preparation
Authors: Wang Long Yao , Pan Fan Rong , Wang Lan
Published: August 2014

Antimony doped tin oxide (ATO) is an oxide material with well electrical conductivity. The composite material of Ti based ATO is prepared with Ti particles (45 μm) according to the thermal decomposition method. The resistivity of the material has been analyzed with a measurement device under 1.7 MPa in particles form. The factors influencing the resistivity were studied and optimized in this work. In order to minimize the resistivity of the material, the optimum conditions are putted forward as: mass ratio of coating solution 15% (SbCl3 to SnCl4⋅5H2O), repeating coating process 20 times (coating with the solution and then dried at 100 °C), sintering at 450 °C for 15 min. Under the optimum experimental conditions, the resistivity of the composite particles is 232 Ω·m. Furthermore, ATO coating improved the properties of the composite material in the oxidation resistance.
Effect of B4C-Si3N4 on Crystallization and Sintering of Fused Quartz Ceramic Material
Authors: Bu Jing Long , He Yan Feng , Shen Shu Bin , Chen Yue Jun , Gu Ying Lei , Wang Zhi Fa
Published: August 2014

Fused quartz granules (d50=19 μm) were used as raw material, and B4C-Si3N4 (1:1, in mass) was used as additive with dosages of 1% (in mass, similarly hereinafter), 2% and 3%. Fused quartz ceramic materials were fabricated in reduction atmosphere at 1250 °C, 1300 °C, 1350 °C and 1400 °C for 1 h. The apparent porosity, bending strength and thermal expansion ratios of the samples were examined and they were analysed by means of XRD. The results showed that the sample sintered at each temperature with 1% B4C-Si3N4 had the lowest apparent porosity, the highest bending strength. This indicated that 1% B4C-Si3N4 was conducive to sintering of fused quartz ceramic materials. The results of XRD analysis and thermal expansion ratio analysis showed that 1% B4C-Si3N4 compound additive had obvious effect on inhibiting crystallization of the samples sintered at various temperatures. It can be deduced that the 1% B4C-Si3N4 compound additive plays the excellent role in inhibiting crystallization and facilitating sintering of fused quartz ceramic materials.
Finite Element Analysis of the Tensile Properties of Composite Laminates with Open Holes
Authors: Wang Xiao Qiang , Zhao Wei Tao , Fang Bo , Lu Shao Wei , Zhang Ye Wei
Published: August 2014

For different technical reasons, cutouts such as holes in thin-walled structures are inevitable and are of significant technical relevance. Unfortunately open holes usually lead to an undesired stress concentration at the hole vicinity and a reduced load carrying ability of the structure. Therefore the mechanical properties of fiber-reinforced composite laminates with open holes are studied in the paper. The influences of the size and shape of the holes are investigated. A progressive failure finite element model is developed with software ABAQUS. Different failure modes of the composite laminates with various holes are simulated under the Hashin failure criterion. The computational results show that the hole/s have a significant effects on composite laminates properties, and the conclusion can be provided as a good reference for the design of the composite laminates with hole/s.
Numerical Simulation on Ballistic Performance of Wf/Metallic Glass Composite with Tungsten Fiber Spacing
Authors: Zhu Li Jun , Wu Hong , Zou Min Ming , Jia Wan Ming , Shi Hong Gang , Tian Kai Wen
Published: August 2014

The penetration characteristics of tungsten fiber reinforced metallic glass matrix composite with different tungsten fiber spacing were simulated by LS-DYNA programme. It is indicated that J-C constitutive model for describing deformation behaviour of tungsten fiber can accurately reflect the penetration process of the composite. The simulation results show that the composite has obvious self-sharpening behaviour, and its penetration performance is higher than tungsten alloy. The higher penetration performance depends on close-packing of tungsten fibers separated by metallic glass.
Decontamination Performance of ZnFe2O4/Expanded Graphite Composites
Authors: Liu Zeng Jun , Wang Wei Xiang , Shen Jun Hai , Li Liang Chao
Published: August 2014

A series of ZnFe2O4/expanded graphite composites (EG/ZF) were prepared by the chemical precipitation method. The structure, composition and morphology of the as-prepared samples were characterized. Taking methylene blue (MB) as the simulate organic pollutant, the influences of various factors on the decontamination of the as-samples and their reusing performance were researched. The results showed that the decontamination activity of the EG/ZF composite with mass ratio of EG to ZF equal to 0.8 reaches the maximum in the MB solution of pH = 5, and has good performance for repeated use. What’s more, the possible mechanism of decontamination was studied further.
Friction and Wear Performance of Ti-Al Matrix Composites under 650°C
Authors: Wang Xiu Ling , Yang Li Ying , Wang Shou Ren , Zhang Yi , Yu Hang Hai
Published: August 2014

Ti-Al alloy matrix self-lubricating composites were fabricated by the method of high temperature hot pressing sintering. The friction and wear performance of self-lubricating Ti-Al matrix composites were studied at high temperature. The study found that the friction coefficient decreased with the increase of solid lubricant, CaF2 and BaF2 had played good lubrication. when the lubricant BaF2-CaF2 mass fraction was 10%, the wear rate of composites to the lowest, it was 0.29×10−7 cm3N-1m-1 in 650°C high temperature.
Research on Properties of Crosslinkable Polymer-Based Semi-Conductive Shielding Composites
Authors: Han Bao Zhong , Zhang Cheng Cheng , An Bang , Li Chun Yang , Li Chang Ming
Published: August 2014

In order to select effective carbon black (CB) and matrix resin for fabricating semi-conductive shielding materials of XLPE insulated high voltage cable, the crosslinkable composites were prepared by melt blending different types of CB with three types of copolymer resin, and the crosslinking samples were compressed. The electrical conductivity, mechanical properties, thermal elongation properties and rheological properties of the crosslinkable semi-conductive composites were measured. The research results indicated that compared to EVA-based and EEA1-based composites, the EEA2-based composites have the lowest volume resistivity and the best rheological properties, and the CB content has less effect on their mechanical properties. The properties of the composites with CB1 were superior to that of the composites with CB2. The composites prepared with CB1 and EEA2 present the best overall properties. These composites are expected to be used in the manufacture of semi-conductive shielding layer for high voltage cable.
Study of Preparing β''-Alumina by Solid-State Synthesis
Authors: He Han Wei , Wang Xiao , Pan Deng Yu
Published: August 2014

In this paper, β''-alumina powders were prepared by solid-state synthesis method with different kinds of sodium compounds such as sodium carbonate, sodium bicarbonate, sodium oxalate, sodium acetate and sodium citrate. Each sodium compound was mixed with α-alumina by ball-milling, and then dried and calcined in muffle furnace, respectively. In order to confirm the superior condition for different sodium compound to prepare β''-alumina, original raw material with different powders molar ratio and calcination temperature were applied. The phase compositions of mixed powders after calcination were analyzed by X-ray diffraction (XRD). The results show that different kinds of sodium compounds which are just composed of sodium, carbon and oxygen all can be used as sodium source for preparing β''-alumina, but different sodium source compounds need different calcination temperature to form β''-alumina phase. And the molar ratio of sodium compound to α-alumina has an effect on the final content of β''-alumina.
Self-Assembly of Gold Nanoparticle Arrays with Anodic Aluminum Oxide Template
Authors: Wang Fei , Xu Hui , Wang Ying Wei , Fang Jing Yue , Chen Wei , Zhang Xue Ao
Published: August 2014

Nanoparticles and their ordered arrays have many important applications in fields such as electronic, optical, memory storage devices and sensors. Herein, a simple method was used for fabricating three-dimensional ordered gold nanoparticle arrays with template technique. Gold films were deposited onto anodic aluminum oxide by using electron beam evaporation. After thermal annealing, interestingly, order arrays of gold nanoparticles were obtained by a thermodynamically driven self-assembled process. The spectrum taken by UV-Vis spectrophotometer demonstrates clear surface plasmon resonance at around 500 nm, which appears blue-shift compared with usual gold nanoparticles.
The Comparison of Sound Absorption of Kapok-Based Fiber Nonwoven Fabrics
Authors: Liu Xue Ting , Yan Xiong , Hong Jie , Zhang Hui Ping
Published: August 2014

As a natural fiber, kapok fiber has the high hollow degree that is very good for sound absorption. Four different kinds of kapok-based fiber nonwoven fabrics, made by kapok fiber mixing with hollow polyester, viscose fiber, PP fiber and cotton fiber respectively, were made and the sound absorption coefficients were measured in the frequency region of 100 - 6300 Hz by using a two-microphone transfer-function method. The comparisons of the sound absorption for four types of materials with similar thickness and densities with no air gap and with 1 cm, 3 cm air gap were made. The results indicate that the sound absorption of kapok/hollow polyester fiber nonwoven fabrics is superior to those of other three ones and kapok/hollow polyester fiber nonwoven fabrics can be used for sound-absorbing materials in engineering.
Synthesis , Characterization and Photophysical Properties of a New Cui Complexe Contain Bis[2-(diphenylphosphino)phenyl]ether and 2-(naphthalen-2-yl)-1-phenyl-1H-imidazo[4,5-f][1,10]phenanthroline
Authors: Li Qiang , Zhong Rong Feng , Zhao Feng
Published: August 2014

In this paper, a new diimine ligand of 2-(naphthalen-2-yl)-1-phenyl-1H-imidazo[4,5-f][1,10]phenanthroline(E2) and its corresponding CuI complex contain Bis[2-(diphenylphosphino)phenyl]ether were synthesized and characterized by 1H NMR successfully. Experimental data confirm that Complex [Cu(E2)(DPEphos)](PF6) is high-energy-emitting one. The broad band emission upon excitation at λ = 400 nm with the emission maximum locates at λ = 582 nm was observed. This makes them potential candidates as cheap emitting materials.
Sulfonated Poly(Fluorenyl Ether Ketone) Membranes with Suppressed Semi-Interpenetrating Crossover and Enhanced Proton Selectivity for Vanadium Redox Flow Batteries
Authors: Xie Wen Mei , Zheng Ron Xue , Song Xun , Ding Fu Chuan , Huang Xue Hong , Ling Qi Dan
Published: August 2014

A series of hybrid membranes with special microstructure, based on sulfonated poly (fluorenyl ether ketone) ionomer (SPFEK, IEC=1.74 mequiv.g-1) and secondary amine group containing SiO2 (SiO2–NH–NH2), has been successfully designed and prepared for vanadium redox flow battery (VRB) application. The hybrid membranes are prepared by simply adding KH792 into the SPFEK solution in N,N’-dimethylacetamide (DMAc), followed by dispersion, co-condensation and solvent casting. The water uptake, mechanical property, proton conductivity, (VO)2+ permeability and single cell performance are investigated in order to understand the relationship between morphology and property of the membranes. The hybrid membranes show dramatically improved proton selectivity when compared with SPFEK. The vanadium ion (VO)2+ permeability through the hybrid membrane is about 10 times lower than that of virgin SPFEK. The columbic efficiency and energy efficiency of the single cell of the hybrid membrane are higher than the SPFEK membrane. The results inidicate that hybrid membranes of this type are promising for VRBs.
Preparation of Novel Diester Gemini Quaternary Ammonium Salt Cationic Surfactant
Authors: Miao Zong Cheng , Ren Jian Wei
Published: August 2014

In order to obtain a biodegradable gemini cationic surfactant with high surface activity, N, N-dodecyldimethyl amine, epichlorohydrin and adipic acid were used as raw materials to synthesize the surfactant, and Fourier transform infrared spectroscopy was used to characterize the groups. And then the interface characteristics of the surfactant were studied in detail. The critical micellar concentration (CMC) was determined by surface tension test to obtain the values of CMC and surface tension at CMC. The foam ability and foam stability of the gemini cationic surfactant were also discussed through contrast octadecyltrimethyl ammonium chloride and cetyltrimethyl ammonium chloride.
The Influences of Additives on the Corrosion Resistant Properties of Electroless Plating Ni-Co-P Alloy on the AZ91D Magnesium Alloy
Authors: Yu Zu Xiao , Sun Ya Li , Huang Xin
Published: August 2014

To improve the anti-corrosion properties of the AZ91D magnesium alloy, the electroless plating Ni-Co-P on the AZ91D magnesium alloy is necessary. The influences of additives (ammonium fluoride (NH4F) and hexamethylenetetramine (HMTA)) on deposition rate, corrosion rate, acid resistance, corrosion current, corrosion potential and webster hardness of electroless plating Ni-Co-P alloy coating, were investigated using electrochemical methods, etc. The results show that the deposition rate and corrosion resistance properties of electroless plating Ni-Co-P are obviously improved when the additives, including NH4F (2%) and hexamethylenetetramine (HMTA, 1%), are added into plating solution, respectively. In addition, the global particles in the Ni-Co-P coating become smaller with the addition of NH4F by comparison with no additives and coatings are dense, uniform and defect-free.
Microstructure and Wear Resistance of In Situ Synthesized TiC-TiB2 Particulate Reinforced Ni-Based Composite Coating by Argon-Arc Cladding
Authors: Wang Zhen Ting , Feng Fan
Published: August 2014

In situ synthesized TiC-TiB2 reinforced Ni based coating was fabricated by argon arc cladding on Q235 steel substrate using titanium, boron carbide, Ni60 as the precursor powders. The phase composite on and microstructure of the clad layer were investigated by means of X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) and Energy Dispersive Spectrometer (EDS). The results show that uniformly distributed TiC particles with the black petals shape and TiB2 particles with rod shape could be synthesized by the situ reaction. Compared to those unreinforced Q235 steel substrate, the hardness and the wear resistance of TiC-TiB2 reinforced Ni based composite coating were significantly enhanced.
Retardant Properties of Nanosilica/PTFE Nanoparticals-Reinforced Polypropylene
Authors: Zhang Zhen Lu , Li Dong Li , Xu Wen Cai , Fu Ya Bo , Liao Rui Juan
Published: August 2014

This work reports the flammability properties of Nanocomposites reinforced with silica and PTFE nanoparticles and toughened with an elastomeric ethylene-vinyl acetate (EVA). Through trial and simulation study of the flame retardant thermoplastic polymer and melting characteristics of PP in the combustion process.The study found that modified PP composites have good flame retardancy compared to PP in case of fire relatively.In the study,the melting characteristics of the thermoplastic polymer affected the mass loss rate in the combustion stage.Nanocomposites experienced low plastic mass loss compared with PP, this has been related to pyrolysis mechanism of polymer.In general,The polymers undergoing depolymerization will lead to a rapid volatilization and therefore experienced much less melting.The results showed that:total heat release of nanocomposites was higher than polypropylene, while the average heat release rate, the maximum heat release rate, the average effective heat of combustion, the average mass loss rate, the average specific extinction area, and other indicators were lower than polypropylene.
Influence of Al-Content on the Microstructure and Mechanical Properties in ZrAlN Coatings
Authors: Zhu Xiao Ying , Du Jun , Liu Gui Min , Zheng Xiao Hui
Published: August 2014

Zirconium aluminum nitride coatings have been deposited onto Ti-6Al-4V substrates by reactive magnetron sputtering in order to investigate the influence of Al-content on the microstructure and mechanical properties. The morphology and microstructure of the coatings were investigated by field emission scanning electron microscopy (SEM), X-ray diffraction (XRD), and transmission electron microscopy (TEM). Nanoindentation and Vicker’s indentation methods were employed to measure the hardness and toughness of the coatings, respectively. The results show that a structure of single cubic phase with twinning is formed at Al content of x ≤ 0.23, and a two-phase structure of hexagonal and cubic phase is formed at Al content of x ≥ 0.47. Hardness and toughness of the Zr1-xAlxN coatings show similar tendency with the increasing of Al-content. Both of them reach the maximum values at x=0.23 and drop to the minimum values at x=0.47, after that, they slightly increase with the increasing Al-content. The enhanced hardness and toughness achieved at x=0.23 is ascribed not only to single cubic phase structure but also to twinning structure.
A Study on Color Variance of IMR between PET Coated and Uncoated White Ink by UV Inkjet
Authors: Chen Chang Lang , Chiou Lihrong , Chang Yu Tung , Hsu Weichieh
Published: August 2014

IMR can print out excellent textures and effects on irregular surfaces. Many products decorated by IMR are protected from water and fading, and these kinds of decorations strongly increase beauty, desirability and value of the objects. Therefore, this research is to investigate the potential use of combining IMR with UV inkjet printing and to compare color variance of IMR between PET coated and uncoated white ink. Study results show that the SIDs of PET with white ink is higher about 0.15 to 0.2 than the PET without white ink. The SIDs of PET without white ink will decrease and the SIDs of the PET with white ink will increase when transferred. The PC of PET without white ink is about 10 to 15 higher than the PET with white ink. After transferred, the Color Gamut became smaller than before. Especially for the PET without white ink, its color differences △E can reach 40. In addition, the color gamut became smaller when transferred.
Effect of very Low Frequency Electromagnetic Radiation on Acetylcholine Esterase Activity
Authors: Wang Hong , Du Zheng Wei , Guo Pei Dong , Tang Yun Ming
Published: August 2014

Acetylcholinesterase (AChE) is the enzyme that controls the acetylcholine (ACh) concentrations in cholinergic synaptic clefts by hydrolyzing ACh to choline and acetate. In this paper, we investigate the effect of very low frequency (VLF) electromagnetic field (EMF) radiation on AChE activity. AChE was exposed to VLF-EMFs with electric field intensity ranged from 0 to 200V/m and exposure time ranged from 0 to 120min. The results demonstrated that the VLF-EMF increased enzyme activity when the intensity ranged from 80V/m to 100V/m as well as exposure time ranged from 60min to 80min. And the AChE activity decreased when the intensity ranged from 120V/m to 140V/m and exposure time ranged from 20min to 120min. Thus, those results are significant in clinical treatments.
Overexpression and Phylogenetic Analysis of a Thermostable α-Glucosidase from Thermus thermophilus
Authors: Li Xun , Gu Hua Xiang , Shi Hao , Wang Fei
Published: August 2014

The α-glucosidase gene agl from Thermus thermophilus HB8 was cloned into expression vector pBV220. The phylogenetic trees of α-glucosidases were constructed using Neighbor-Joining (NJ) and Maximum-Parsimony (MP) methods. Evolution analysis indicated the α-glucosidase from T. thermophile HB8 was distant from the other glycoside hydrolases 4 and 31 α-glucosidases. By weakening the mRNA secondary structure and replacing the rare codons for the N-terminal amino acids of the target protein, the expression level of the agl was increased 30-fold. The recombinant AGL was purified by the heat treatment, and had a molecular mass of 61 kDa. The optimal activity was at pH 7.8 and 95°C over a 10 min assay. The purified enzyme was stable over a pH range of 5.4-8.6, and had a 1-h half life at 85°C. Kinetic experiments at 90°C with p-nitrophenyl-α-D-glucoside as substrate gave a Km, and Vmax of 0.072 mM and 400 U/mg. Thus, this report provides an industrial means to produce the recombinant α-glucosidase in E. coli.
Analysis of Fluid Loss-Reducing Mechanism of Humic Acid Acetamide Compound with Lipophilic Property
Authors: Ma Cha , Li Long , Yuan Xu Bo , Cheng Rong Chao , Wang Gang
Published: August 2014

Humic acid acetamide compounds with lipophilic property could dissolve or disperse in oil phase, so they were an important fluid loss additive for oil-based drilling fluids. Compared with water-soluble humic acid derivatives, the fluid loss-reducing mechanism of them was different. With analyzing the mechanism of increasing the flow resistance of liquid phase, bridging plugging, plugging pore and improving the quality of mudcake, the fluid loss-reducing mechanism of lipophilic humic acid acetamide compounds is investigated.
Effect of Storage Conditions on Apparent Viscosity of Oleogel Developed by β-Sitosterol and Lecithin with Sunflower Oil
Authors: Wan Wen Bo , Han Li Juan , Liu Guo Qin , Liu Xin Qi
Published: August 2014

The influence of storage conditions on apparent viscosity of mixtures of β-sitosterol and lecithin in sunflower oil was studied using rheology. The results showed the apparent viscosity of oleogel decreased with the increase of the speed of shear and storage temperature, while incresed with prolong of time in experiment conditions. The β-sitosterol and lecithin ratio also affected the apparent viscosity; solutions with ratio (70 β-sitosterol-30 lecithin) performed the highest apparent viscosity. What’s more, all the samples were pseudoplastic fluid. The apparent viscosity of the oleogel depends on storage temperature, storage time and organogelator ratios.