bluuebunny/crossref_metadata_2025 huggingface dataset:
Le Rouge et le Noir
Authors: Thorel Sylvie
Published: August 2018

On examine ici les paradoxes exprimés par le voisinage d’un titre poétique, Le Rouge et le Noir, avec deux sous-titres renvoyant à l’histoire contemporaine, Chronique du xixe siècle et même Chronique de 1830. Le premier n’a certainement pas délivré encore tous ses mystères, tandis que les seconds semblent limpides, et leur coexistence intrigue. On développe l’hypothèse que Stendhal, en faisant coïncider le temps du récit avec celui de son écriture, se consacre aux conditions de possibilité même du roman lorsqu’il tend au lecteur cet étrange miroir qui, suivant la manière dont il l’oriente, tantôt « reflète l’azur des deux, tantôt la fange des bourbiers de la route ». Tandis que la chronique se déroule dans la boue du temps historique, Le Rouge et le Noir, réalisation d’un éternel présent de l’écriture, s’en extrait - Stendhal évolue librement parmi les êtres de sa création, les fait agir et penser à mesure, sans autre justification que le rêve héroïque si mal accordé à l’esprit du temps qu’il réalise avec eux.
Saturne aux deux visages
Authors: Gheeraert Tony
Published: August 2018

Que reste-t-il aujourd’hui de L’Astrée, roman tenu pour un chef-d’œuvre « incomparable » par tout le xviie siècle ? La fadeur du vert céladon, quelques clichés de bergères trop sages gardant de trop blanches brebis, et une réputation de roman illisible. L’Astrée mérite pourtant mieux, à coup sûr, que les raccourcis et les stéréotypes. Le présent essai, destiné aussi bien à l’étudiant qu’à l’amateur de littérature (ou de belles histoires), offre quelques pistes susceptibles de donner à un lecteur du xxie siècle l’envie de franchir les portes de ce roman-univers.
Petite histoire du Cirque-Théâtre d’Elbeuf
Authors: Sizorn Magali , Lefèvre Betty
Published: August 2018

Ce texte propose à tous un voyage dans un lieu exceptionnel : le Cirque-Théâtre d’Elbeuf. Cette promenade se fonde sur la présence vivante de cet espace dans l’imaginaire collectif de ceux qui l’ont fréquenté. En cela, il s’agit moins de montrer le Cirque-Théâtre dans sa vérité historique que dans les traces gardées en mémoire par ses habitants.

Cirque, cinéma, lieu de meetings, salle de boxe ou espace d’expression d’une communauté, le Cirque- Théâtre stimule nos imaginaires et fonde encore et toujours le lien social.

Cet ouvrage a également vocation pédagogique. Par le récit de la mise en œuvre complète d’une enquête de terrain, l’étudiant en sciences humaines et sociales peut s’initier à une démarche de type qualitatif. Cette expérience ne se pose pas comme modèle, mais tente de dévoiler une méthode en acte
Louis Sauvageot (1842-1908)
Authors: Nasi Sophie
Published: August 2018

Cet ouvrage propose de redécouvrir l'œuvre d'un architecte quelque peu oublié et qui a exercé une part importante de sa carrière à Rouen. Formé en dehors de l'École de beaux-arts, proche de Viollet-le-Duc, Louis Sauvageot (1842-1908) est une figure à la fois exemplaire, témoin de la vigueur de la pratique architecturale en France à la fin du xixe siècle, et atypique, car rien ne laissait présager que ce jeune bourguignon issu d'une famille de tonneliers finirait sa carrière comme inspecteur général des Édifices diocésains puis des Monuments historiques.

Son activité prend son essor en 1871 lorsqu'il est nommé architecte en chef de la ville de Rouen. Cumulant ensuite les fonctions d'architecte en chef des Monuments historiques puis des Édifices diocésains dans la même ville, il va dès lors exercer une véritable mainmise sur la commande publique, aussi bien dans le domaine de la construction que de la restauration et ce, pendant près de trente années. De fait, Rouen met en œuvre au début de la IIIe République un complet renouvellement de ses équipements, rattrapant ainsi le retard accumulé dans le domaine édilitaire. D'une manière générale, les réalisations de Sauvageot se scindent entre une production sérielle et utilitaire, dans laquelle figurent en bonne place les écoles communales et d'autre part, des réalisations prestigieuses comme l'église Saint-Hilaire, le musée-bibliothèque et le théâtre des Arts.

L'empreinte laissée sur les édifices anciens de Rouen est tout aussi considérable et Sauvageot va largement contribuer à modeler l'image du centre historique, avec le complet soutien des institutions. Il faut dire que dès les années 1880, un infléchissement de la politique de la ville est perceptible, marqué par un intérêt ranimé pour le centre ancien. Les chantiers de restauration de la cathédrale et du Gros-Florloge notamment, marquent une étape importante et il ne faudrait pas perdre de vue que le vieux Rouen doit en fait beaucoup au xixe siècle ; car c'est bien une vision de la période médiévale telle que l'imaginaient Sauvageot et ses comparses qui nous fait aujourd'hui rêver.
Les métamorphoses du désir. Étude des Amours de Ronsard
Authors: Vintenon Alice
Published: August 2018

Publiés pour la première fois en 1552, Les Amours constituent l'un des grands événements littéraires de la France du XVIe siècle : maintes fois imité à la Renaissance, le recueil est d'emblée perçu comme un chef-d'œuvre, et fait même l'objet d'un commentaire savant, rédigé par Marc-Antoine Muret.

Le présent volume propose de situer l'œuvre dans son contexte poétique en montrant comment elle mêle des références littéraires (pétrarquisme, épopée...) et philosophiques (néoplatonisme, épicurisme...) très hétérogènes. Mais il souligne aussi ce qui fait la nouveauté des Amours, tant dans la présentation matérielle du recueil et dans sa pratique du sonnet que dans sa distance désinvolte à l'égard de ses sources et modèles.

Trois « entrées » dans l'œuvre sont proposées : la première évoque le contexte de parution du recueil et ses particularités formelles ; la seconde, sa philosophie de l'amour ; la troisième, son usage des références philosophiques et mythologiques.
Les origines. Une lecture de La Fortune des Rougon
Authors: Thorel Sylvie
Published: August 2018

Zola donnait Les Origines pour le « titre scientifique » de La Fortune des Rougon : origine de l'Empire, de la famille des Rougon-Macquart, de la série des Rougon-Macquart - ainsi déclinées au pluriel, « les origines » produisent un curieux effet de dispersion. Sont-elles même assignables ? En faisant jouer et varier sur des plans nombreux, suivant un régime allégorique, les principes de répétition et de relance qu'il isole dans les événements de décembre 1851, Fauteur de La Fortune des Rougon met en œuvre une philosophie de l'histoire qui doit trouver sa forme exclusive dans l'écriture romanesque.
Surface β-Cyclodextrin Polymer Coated Fe3O4 Magnetic Nanoparticles: Synthesis, Characterization and Application on Efficient Adsorption of Malachite Green
Authors: Liang Wen Ting , Li Dan , Ma Xue Wen , Dong Wen Juan , Li Jing , Wu Rui Fang , Dong Chuan , Dong Qing Chen
Published: August 2018

Surface β-cyclodextrin polymer coated Fe3O4 magnetic nanoparticles (NPs) were prepared by anchoring pyromellitic dianhydride derivate-b-cyclodextrin polymer (b-CD-P) onto the surface of Fe3O4 magnetic NPs, which is generated in situ through a co-precipitation method. The transmission electron microscopy (TEM) result indicates that Fe3O4@β-CD-P NPs have an effective average size of 15 ± 2 nm. The surface coated layer β-CD-P was confirmed by Fourier-Transformed Infrared Spectroscopy, and the amount of which was determined to be 138.2 mg g-1 by thermogravimetric analysis. To explore the potential application of such nanocomposites for organic pollutants adsorption, malachite green (MG), a typical cancer-causing water pollutant was evaluated by spectrophotometric method. It was finally learnt that, the adsorption rate of MG by Fe3O4@β-CD-P NPs follows pseudo-second-order kinetics with adsorption isotherm fitted by the Langmuir isotherm model well. The maximum adsorption capacity was measured to be 88.49 mg g-1 at 25 °C. Additionally, a good recyclability of the Fe3O4@β-CD-P was observed over four usage cycles, with slight decrease of adsorption capability.
The Nature of Intrinsic Stresses in Thin Copper Condensates Deposited on Solid State Substrates
Authors: Koman Bohdan , Balitskii Olexiy A. , Yuzevych Volodymyr
Published: August 2018

Size effect for intrinsic stresses and thermodynamics of films formation established taking into account the nature of stresses in copper condensates deposited on solid state substrates. We believe that surface energy changes during layer by layer deposition in such condensates with chaotically dispersed areas (possessing different values of Young’s modulus) define the film’s mechanic parameters. The quantitative estimations of mechanical stresses are calculated for layer by layer film growth. The resulting intrinsic stresses (ISs) in copper condensates nature from local static ones, superposed within the area of a film. The latter arose due to anisotropy of interface interaction energy parameters.
Plasmonic Effects, Size and Biological Activity Relationship of Au-Ag Alloy Nanoparticles
Authors: Shaikh Ahson Jabbar , Batool Maria , Yameen Muhammad Arfat , Waseem Amir
Published: August 2018

The plasmonic effects of Au-Ag alloy nanoparticles, gold nanoparticles (AuNPs), and silver nanoparticles (AgNPs) are studied and compared to their size. Various factors that affect the size of alloy nanoparticles are varied such as concentration and ratio of gold and silver salt, time of addition of reducing agent, temperature and pH. Addition of reducing agent at different time intervals for the synthesis of pure and alloy Au-Ag NPs shows a gradual increase in size, as well as increase in heterogeneity of nanoparticles with delayed addition of reducing agent. Temperature dependent alloy nanoparticles also shows a gradual increase in size with increase in temperature. pH dependent alloy nanoparticles show decrease in size with increase in pH from 4 to 8. Their size is characterized by SEM and corelated with UV-Vis spectroscopy. Furthermore, alloy nanoparticles synthesized by varying temperature are also characterized for their antibacterial studies against Escherichia coli and Staphylococcus aureus strains. Nanoparticles synthesized at high temperature (100°C) have shown higher bioactivity against both organisms due to small and uniform size nanoparticles, while nanoparticles synthesized at lower temperature (50°C) have lower biological activity. Alloy nanoparticles synthesized at 60°C and 70°C are more active against E. coli while those of 80°C and 90°C are more active against S. aureus.
All Solution-Processed Quintuple-Layer Organic Light-Emitting Diodes Containing Organic-Inorganic Hybrid Active Layers Fabricated by Sol-Gel Method
Authors: Jitsui Yusuke , Ohtani Naoki
Published: August 2018

Organic-inorganic hybrid thin films were fabricated using the sol-gel method and applied to multi-layer organic light-emitting diodes (OLEDs) as an active layer. A polymer emissive material poly (9,9-dioctyl-fluorene-co-N-4-butylphenyl-diphenylamine) (TFB) was solved in a sol-gel reaction accelerator perhydropolysilazane (PHPS). The PHPS solution turned into SiO2 by humidity treatment. Thus, the TFB:PHPS solution became SiO2 thin films in which the organic emissive material TFB was dispersed. All the organic layers of OLEDs can be fabricated using solution-process because the organic-inorganic hybrid active layer is not soluble with the adjacent organic layers. Consequently, we successfully fabricated quintuple-layer OLEDs consisting of the following five organic films: hole-injection, hole-transporting, active (organic-inorganic hybrid) electron-transporting, and electron-injection layers. Electroluminescence (EL) was successfully observed.
Collection of Silicone Nanoparticles in Ingot Growing Process and Analysis of Particle Characteristics
Authors: Kim Junghyun , Ahn Jiho , Kang Hee Yong , Lee Gyo Woo
Published: August 2018

This study was conducted to investigate the characteristics of silicon nanoparticles using waste vapors generated from a single-crystal silicon ingot growth furnace and to study their potential applications. The silicon vapors generated in the silicon ingot growth furnace were collected in the form of nanoparticles, and SEM, EDS, BET and XRD analyzes were performed to analyze the characteristics of the collected particles. The particles were in the form of agglomerated nanoparticles with a specific surface area of ​​176 m2 / g and were amorphous SiOx particles with low crystallinity. In the future, we plan to study the application fields of the collected nanoparticles.
High Density Polyethylene/Date Palm Fiber Composites: Effect of Fiber Loadings on the Dynamic Mechanical Thermal Properties
Authors: Chafidz Achmad , Faisal R.M. , Kistriyani Lilis , Lestari Ajeng Y.D. , Hartanto Dhoni , Rizal Muhammad
Published: August 2018

The increasing environmental issues has resulted in the trend of the use of renewable or natural source (green) fillers in the polymer composites fabrication. Among these green fillers is called natural fibers or plant fibers. One particular plant fibers that became the topic of the present work is date palm fiber (DPF). In the present work, DPF at different loadings (i.e. 0, 5, 10, 20, 30 wt%) were incorporated (as fillers) in the high density polyethylene (HDPE) matrix to fabricate HDPE/DPF composites. Further, we have investigated the effect of DPF loadings on the dynamic mechanical thermal properties of the composites. The dynamic mechanical thermal analysis (DMTA) results exhibited that the storage modulus of the composites increased with increasing DPF loadings. Additionally, all the storage modulus values of the composites were higher than the neat HDPE in all temperature ranges. For example, at temperature of 60°C, the storage modulus enhancement of the composites as compared to the neat HDPE were about 26, 76, 134, and 225% for 5, 10, 20, 30 wt% of DPF loadings, respectively. Additionally, the relationship between the DPF loadings (wt%) and temperature (°C) on the storage modulus of the HDPE/DPF composites was modeled using a logarithmic equation. Based on the data plotting between the experimental data and modeled data, the logarithmic equation was found to be fitted with the experimental data satisfactory.
Preparation of Crude Oil Flow Improver from Vegetable Oil and the Performance Evaluation
Authors: Xu Jing Fang , Guo Zhen , Zhang Fa Wang , Wang Da Chuang , Wang Zhen , Zhang Yong Ming , Chen Gang
Published: August 2018

In this work, a series of hydroxylmethyl pentamine (HMPA) was synthesized from vegetable oil, tetraethylene pentamine and hexamethylenetetramine, which was evaluated as a crude oil flow improver. The results showed that HMPAs have good viscosity reduction effect on the crude oil from Yanchang Oilfield, with the highest viscosity reduction rate of 93%. The highest pour point reduction depression was achieved as 5.4°C. Paraffin crystal morphology characterization was conducted on the crude oil to elucidate the mechanism of viscosity reduction and pour point depression.
A Study on Fabrication of Ultra-Precision Diamond Tool and Length Optimization for Improving the Stability
Authors: Baek Seung Yub , Chu Jin Ho , Jung Sung Taek
Published: August 2018

A tool for fabricating micro/nanopatterns was utilized in space optics, virtual reality, augmented reality, and semiconductor industry. Nowadays, demand of manufacturing technique for ultra-precision is continuously increasing virtual reality and augmented reality industry across the board and core technique for manufacturing next generation lens is cutting tool fabricating technique with nanoscale. In particular, tools of micro/nanosize for ultra-precision machining was made by using an ultra-precision grinding, but it was difficult to fabricate tools which have under micro scale. Recently, results of studies with many researchers were pulsed laser ablation, electric discharge machining and precision grinding. However, previous studies are unsuitable in making tools of micro/nanoscale. Due to unique physical properties of diamond, it can be easily controlled by using focused ion beam. The surface properties of the diamond layer are affected because of the amorphous damage caused by the FIB gallium ions collision, implantation and these effects can make to be able to control the geometry of cutting tool. In this study, we carried out in fabricating diamond tools under micro scale by using FIB milling through various process studies and determined in order to optimize the length of unstable tool.
Micro-Crack Analyses of Chromium Steel JIS-SCr 420 for Helical Gear Transmission
Authors: Boonmag Visanu , Wisesook Ongarj , Phukaoluan Aphinan , Pluphrach Ganwarich
Published: August 2018

This research aims to investigate micro-crack on a failed for helical gear transmission which was to adjust the engine to increased horsepower. The helical gears made are from chromium steel JIS-SCr 420. The spectrophotometer test machine was used to detect chemical composition, Mechanical properties were evaluated by Vickers hardness and microstructural analysis with an optical microscope, which the crack of the surface layer and energy dispersive spectroscopy using a scanning electron microscope. The results showed that the fracture characteristic of the helical gear’s surface was expected to beach marks and break away. It can be seen that the mixing failure area of oxide inclusion with carbide surrounding before the liquid state of material will be solidified which caused the failure cause of this helical gear. The summary analysis results can be accorded with the assumption of this research and which help prolong service life of the component.
Influence of Magnetic Field on Formation of Short Range Order Regions in Liquid Metals: Fluctuation Hypothesis
Authors: Arkulis Mikhail , Logunova Oxana , Dolgushin Denis
Published: August 2018

The aim of this investigation is to provide theoretical justification of the crystallizing nucleus formation in liquid iron. To solve this problem, the authors put forward the fluctuation hypothesis: short range order region formation in liquid metal takes place due to temperature fluctuations, and the temperature of the short range order is the temperature fluctuation around Kelvin scale zero in the course of crystallization time. The investigations were carried out for liquid state of the substance, in particular, for iron in paramagnetic state at the melting temperature. Analytical derivation of the temperature fluctuation value was given. Analytical expressions were obtained to define the average number of atoms in the short range order region for crystallizing iron. The investigation results show that short range order contains enough atoms to provide interaction with pulsed magnetic field resulting in the increase in the number of crystallization nuclei and in the decrease of their size. The obtained results can be used in the decision-making process concerning some manufacturing operations aimed at providing homogeneous structure of metals, particularly, in ferrous and non-ferrous metallurgy.
Preparation and Properties of a Novel High-Strength Foam
Authors: Wang Xue Shan , Deng Shi Feng , Huang Yan Chun , Liu Zhong Qi
Published: August 2018

A novel high-strength foam (PSA foam) was prepared by adding foaming agent in silicon-containing arylacetylene (PSA) via free heat foaming. The dispersion of foaming agent was observed by Scanning Electron Microscopy-Energy Disperse Spectroscopy (SEM-EDS) and the result indicated that the foaming agent was dispersed uniformly in PSA. The microstructure of the PSA foams prepared with different foam temperatures were characterized by SEM and the results showed the PSA foam had uniform pores when the foaming temperature was 165°C. Compressive strength of the PSA foam could reach 10.3 MPa. Furthermore, PSA foam possessed excellent thermal stability, dimensional stability and heat insulation performance: char residue reached 92.3% at 800°C under nitrogen atmosphere; the highest coefficient of thermal expansion was 83*10-6/K; the thermal conductivity was 0.0724 W/(m•K).
Effects of Annealing Process on Mechanical Properties of Weather-Resistant Steel Welding Joints
Authors: Zhang Qiang , Wu Zhe , Li Hong Wu
Published: August 2018

In this paper, the mechanical properties of Q355NH resistant steel welded joints are studied. Through the analysis of mechanical properties of welded joints, the results showed that the tensile strength of the welded joints decreased after annealing and the elongation increased. The impact test results of tensile specimens before and after annealing showed that the impact energy of the weld area increased greatly after annealing, while the impact energy of the heat affected zone changed little. Furtherly, fatigue strength of specimens before and after annealing was compared, and the results showed that under the condition of high cycle fatigue, the un-annealed specimens were broken and the fracture position was located on the parent metal, whereas the annealed specimens did not break.
Study on the Potential of Fabricated Non-Biodegradable Plastic Waste (N-BPW) Liner as Alternative to Conventional Geomembrane
Authors: Bashar Nur Azwa Muhamad , Alias Salina , Tay Chia Chay , Alias Nor Fathiah Mohamad
Published: August 2018

This study investigates the potential application of Non-Biodegradable plastic waste (N-BPW) from household (plastic food packaging (PFP)) namely plastic snack packaging (PSP) and plastic bread packaging (PBP) as an alternative to conventional liner material in landfill. The samples were prepared into a single and fabricated layer. The fabricated layers were prepared by applying hot-pressing technique to joint between layers. Then the prepared liners were tested for its chemical and physical properties through Ultimate Tensile Strength Test (UTS) and Fourier Transforms Infrared Spectroscopy (FTIR). The tested samples were compared with conventional geomembrane. Obtained results from FTIR showed that proposed PFP had 70% similar characteristics to geomembrane. In addition, the fabricated samples can sustain high maximum load as compared to conventional geomembrane based on UTS. The proposed liners offer an option to the landfill operators in choosing a good reusable material at a lower cost, solved N-BPW landfilling problems and has great potential to promote as an alternative landfill liner.
Investigation of Bearing Characteristics of High-Cap Pile Foundation under Inclined Load
Authors: Jia Yu Zhuo , Sun Guo Zheng , Li Chang Qing , Tian Long Long
Published: August 2018

To analyze the characteristics of bearing capacity of high-cap pile foundation under inclined load and investigate the influence of vertical and horizontal component on the foundation at different loading angles, based on the background of the Yellow River Crossing project, a three-dimensional finite element model of high-cap foundation is simulated and analyzed with the finite element software ABAQUS. The conclusions are shown as follows: Under the same displacement condition, when the load inclination angle α from 0°(horizontal load) to 80°, the horizontal direction bearing capacity of the foundation increases from 684.8kN to 759.9kN, increases by 10.97%. Expands of vertical load component will affect the pile group effect, the shear force of the back row piles increases with the load inclined angle.
Study on the UV Curing Reactivity of Micro-Injection UV-Curing Molding
Authors: Li Jia Wei , He Jian Yun , Luo Xi Dan , Zhao Chang Song , Xie Peng Cheng , Ding Yu Mei , Xia Yu Zheng
Published: August 2018

In this paper, UV irradiation curing technology is used in the processing and manufacturing of micro structure parts and a micro-injection molding method of UV-curable molding was proposed to process microstructures. The special material for UV light curing injection of microstructural products was developed. The light curing reactivity of the micro injection light curing special material and its effect on the processing molding are studied. The kinetics of light curing reaction of UV curing injecting material were studied by online infrared spectroscopy (RT-IR). The contribution of mono functional monomers to the double bond conversion rate of microstructures is higher than that of high functional monomers. Under the same condition, the mono functional monomer can make the UV curing reaction more complete. Under the same process conditions, the rate of UV curing reaction of high functional monomers is higher than that of mono functional monomers.
Influence of Ball Milling Process on the Pinned Effect of Al2O3/Al Cermet Composite Powder
Authors: Song Jie Guang , Liu Yue , He Long , Li Jin Shi , Chen Wang , Yang Yan , Chen Lin , Guo Song Lin , Yang Chao , Chen Ai Xia
Published: August 2018

The Al2O3/Al cermet composite powders were prepared via the ball milling method,which provide raw materials for preparing high performance cermet materials. The results show that the number of Al2O3 particles on the surface of Al particles increases first and then decreases with increasing the ball milling time and milling rotating speed. The number of Al2O3 particles on the surface of Al particles increases with increasing ball to powder mass ratio. The analysis of the ratio of performance to price shows that the better parameters for preparing the pinned Al2O3/Al cermet composite powders are as follows, the ball milling time 24h,the ball milling rotating speed 100 r/min and the ratio of ball to powder 1:2.
Investigation on Thermal Absorptivity of PCM Matrix Material for Photovoltaic Module Temperature Reduction
Authors: Karthikeyan Velmurugan , Sirisamphanwong Chatchai , Sukchai Sukruedee
Published: August 2018

Photovoltaic (PV) system experience challenges from module temperature (Tmod) increasing particularly due to stagnation of thermal energy (TE) on its surface. Efforts to reduce the Tmod is widely experimented in many ways, like incorporating latent heat storage material (PCM) with PV module to reduce the Tmod through radiation and convection heat transfer. This paper focuses on selecting of an effective thermal absorption material for the fabrication of PCM matrix and optimization of the critical spacing between the PV module and PCM matrix. The thermal absorptivity of Aluminum (Al) and Copper (Cu) were analyzed with and without coated absorber at different spacing conditions. It was observed that Al tube matrix with coated absorber was absorbed 3.0 °C more than copper at 6 mm distance from module. Hence further studies on the Tmod reduction will be effective with the use of Al as PCM matrix tube.
Thermal Resistance of Fly Ash Geopolymers with Alumina as Additive
Authors: Ng Yong Sing , Liew Yun Ming , Heah Cheng Yong , Abdullah Mohd Mustafa Al Bakri , Hussin Kamarudin
Published: August 2018

The present work investigates the effect of alumina addition on the thermal resistance of fly ash geopolymers. Fly ash geopolymers were synthesised by mixing fly ash with activator solution (A mixture of 12M sodium hydroxide and sodium silicate) at fly ash/activator ratio of 2.5 and sodium silicate/sodium hydroxide ratio of 2.5. The alumina (0, 2 and 4 wt %) was added as an additive. The geopolymers were cured at room temperature for 24 hours and 60°C for another 24 hours. After 28 days, the geopolymers was heated to elevated temperature (200 - 1000°C). For unexposed geopolymers, the addition of 2 wt % of alumina increased the compressive strength of fly ash geopolymers while the strength decreased when the content increased to 4 wt.%. The temperature-exposed geopolymers showed enhancement of strength at 200°C regardless of the alumina content. The strength reduced at higher temperature exposure (> 200°C). Despite the strength degradation at elevated temperature, the strength attained was relatively high in the range of 13 - 45 MPa up to 1000°C which adequately for application as structural materials.
Toughened Laminated Alumina/Silica Ceramics Formed by Weakening Interlayer Bonded Strength
Authors: Dong Wen Bo , Fan Jin Peng , Zhang Da Hai , Zhang Jin Gyi , Zhang Juan
Published: August 2018

Low impact toughness is the major obstacle to impede the applications of brittle ceramics such that a very small crack may induce catastrophic fracture of the bulk components. Thus, enhancing the impact toughness of ceramics is virtually important. It is generally accepted that weakening the interlayer binding strength of the laminated material is beneficial to the fracture toughness of the laminated ceramics. In this paper, alumina / silica layered composite ceramics were prepared by impregnating the alumina interlayers with silica sol, wherein the interlayer bonding strength was controlled by adjusting the sintering temperatures from 1000°C to 1600°C. Lowing sintering temperature warrants the weak interlayer bonding strength, which results in the occurrence of the multiple bending strength-strain curves and improve the material's fracture strain and impact toughness. Crack deflection along the weak interface layer is the main mechanism for the enhanced toughness and crack tolerance. When the sintering temperature decreases from 1600°C to 1200°C, impact toughness increases from 4.42 kJ/m2 to 6.95 kJ/m2, and fracture strain measured by three-point bending increases from 0.25% to 0.36%. Finite element software was used to simulate the differences in stress distribution.
Effect of Sintering Temperature on Properties of YAG Porous Ceramics via Atmospheric Sintering Method
Authors: Wang Fang , Xu Ming Han , Chen Ai Xia , Liu Long Tao , Li Zhi Hui , Deng Ru Xin , Song Jie Guang , Chen Lin , Hao Cheng Wei
Published: August 2018

YAG materials have a number of unique properties, the application is very extensive, the burn is due to the temperature is too high or the residence time at high temperatures is caused. The undercurrent is the sintering temperature is too low or the holding time is not enough, resulting in product performance is too low or too small shrinkage. In this paper, the effect of sintering temperature on properties of YAG porous ceramics was investigated. The results showed that the firing temperature of the ingredients will be different and cause the same sintering process and sintering additives content of different samples burned. The increase in the content of SiO2 in the furnish with the sintering aid tends to occur. the effect of temperature on the mechanical properties of the samples after sintering was significant, so the raw materials include 60wt%YAG, 10wt% CaO, 10wt% SiO2 and 20wt% soluble starch, the molding process in 20MPa pressure 10min, the sintering at 1500°C for 2h, the sample porosity is 42.2%, the compressive strength is 5.8MPa, the outside shape is keep intact and the better pore microstructure is shown.
The Influences of Addition of MgCO3 on the Properties of the Magnesia Prepared Using Magnesite
Authors: Zhang Wang Nian , Wang Li , Deng Ni
Published: August 2018

Micropowder MgCO3 was added into magnesite as raw materials to prepare magnesia using a two-step calcination method. The sample magnesite was characterized use X-ray diffraction (XRD) and scanning electron microscopy (SEM). Experimental results showed that the sample insulated at 1600° C for 3 hours before and after sintering presented a linear change rate of 15.6 % in the case of without adding micropowder MgCO3, the prepared magnesia had a bulk density of 2.31 g/cm3 and apparent porosity of 32.8 %, while MgO grain size was 3.11 μm. In the case of adding 8 % micropowder MgCO3, the sample magnesite before and after sintering showed a linear change rate of 17.9 %. The bulk density, apparent porosity of prepared magnesia were 2.46 g/cm3 and 28.1 % respectively, while the grain size of MgO was 5.15 mm.
Preparation and Ablation Performance of BN Fiber Fabrics Reinforced Nitrides Composites
Authors: Qi Xue Li , Zhang Ming Xia , Li Ru , Zhou Chang Ling , Tang Jian Xin , Cheng Zhi Qiang , Wang Zhi Hao , Wang Zhi Hao
Published: August 2018

High-performance three-dimensional boron nitride fiber reinforced silicon nitride (BNf/Si3N4) composites were prepared by the infiltration and pyrolysis (PIP) process using BN fiber fabrics as the reinforcing body and excellent nitride organic precursor (Perhydropolysilazane, PHPS) as the Impregnated liquid. The ablation resistance of the composite was evaluated by plasma jet ablation test in air. The results show that a uniform and dense interface layer is formed on the fiber surface, with thickness is about 100 nm, and the XRD test shows that it is hexagonal BN (h-BN). The density of the composite reaches more than 1.72 g·cm-3 and the bending strength is more than 80 MPa. Under the condition of plasma jet ablation test at 2000 °C / 200 s, the mass ablation rate is 3.32 × 10-4 g/s, the linear ablation rate is 4.78 × 10-3 mm/s. The prepared materials have excellent resistance to high temperature ablation, and are expected to be used in the field of high temperature microwave transparent such as high mach missile radome, antenna window and so on.
The Matrix Cracking Stress and Residual Thermal Stress of 2D SiC/SiC Composite Fabricated by PIP Process
Authors: Qiu Hai Peng , Liu Shan Hua , Wang Ling , Zhang Bing Yu , Chen Ming Wei , Xie Wei Jie , Liang Yan Yuan
Published: August 2018

A two dimensional silicon carbide fiber reinforced SiC matrix (2D SiC/SiC) composite fabricated by precursor infiltration pyrolysis (PIP) process used a liquid SiC ceramic precursor was obtained. Two key properties including matrix cracking stress and thermal residual stress were investigated for this PIP 2D SiC/SiC composites. Three methods were applied to determine the matrix cracking stress in order to obtained a trusted value, and the value of matrix cracking stress for SiC/SiC composite was 75±4 MPa. The thermal residual stress of the composites was calculated by linear regression line according to the loading-unloading-reloading stress-strain curve of the 2D SiC/SiC composite, and the result showed that the value of thermal residual stress of SiC matrix in composite was 20MPa, which means the PIP SiC matrix in the 2D SiC/SiC composite was under the compressive stress when the composite cooling down from the fabrication temperature to the room temperature.
Thermal Expansion of Ca1-xSrxZr4(PO4)6 Ceramics
Authors: Song Yuan Yuan , Zhou Yuan Yuan , Wang Yang , Li Lan , Liu Fu Tian
Published: August 2018

Ceramics with the formula Ca1-xSrxZr4(PO4)6 (x=0.4, 0.45, 0.5, 0.55) have been synthesized by coprecipitation method, an. their structures, phase transitions, thermal expansion properties have been studied by differential sanning calorimetry, scanning electron microscope, X-ray diffraction and dilatometer. The results show that Ca1-xSrxZr4(PO4)6 ceramics sintered at 1400°C had good sintering condition. Unit cell volume basically had no change with substitution of Ca by Sr. The coprecipitation method saved energy and time. It was introduced to increase the relative density of Ca0.5Sr0.5Zr4(PO4)6 ceramic. The coefficient of thermal expansion was about 1.447×10-6/°C.
Quartz Fibers Reinforced SiNB Ceramic Matrix Composites Prepared by PIP
Authors: Gao Long Fei , Li Song , Wang Si Qing , Yu Kun , Zhang Xue Mei , Xiao Yuan Yu , Dong Ke Xin
Published: August 2018

The 2.5D quartz fibers reinforced SiNB ceramic matrix composites (2.5D SiO2f /SiNB) were prepared through polyborosilazane infiltration and pyrolysis (PIP) method. The SiNB ceramic precursors and their pyrolytic products were characterized and the mechanical properties, dielectric properties, micro-structures and fracture mechanism of the composites were investigated. The results of FT-IR spectra and XRD patterns show that when the pyrolytic temperature reached 900°C, the pyrolytic products are essentially inorganic. The tensile strength and the tensile modulus are 65MPa and 30GPa respectively, the tensile strength at 800°C is 35MPa,and the dielectric constant is 3.2, the dielectric loss angle is smaller than 6 ´ 10-3. And the composites are ductile fracture, whose fracture faces have distinct fibers pull-out.
Influence of Carbon Fiber Treatment on Flexural Properties of C/SiC Composites
Authors: Xie Wei Jie , Qiu Hai Peng , Chen Ming Wei , Liu Shan Hua
Published: August 2018

The purpose of this study was to investigate the influence of carbon fiber treatment on flexural properties of carbon fiber reinforced SiC matrix (C/SiC) composites. C/SiC composites were prepared by polymer impregnation pyrolysis (PIP) progress with polycarbosilane (PCS) as impregnant and carbon fiber as reinforcement. The flexural strength at room temperature of the 2D laminated composites were measured and analyzed with different carbon fiber treatment process. It was found that the flexural strength of the composites with carbon fibers coated by pyrolytic carbon was 53.5% higher than that with non-coated carbon fibers. The results also show that the flexural strength of the composites with 1600°C heat treated carbon fibers increased by 25.4% compared with the composites with non-heat treated fibers.
Stress Evolution and Element Diffusion in Bi-Layered Yb2SiO5/ Mullite Environmental Barrier Coatings under High-Temperature Molten Salt Corrosion
Authors: Chen Hong Fei , Du Ya Xiong , Feng Juan , Yang Guang , Gao Yan Feng
Published: August 2018

Yb2SiO5/mullite bi-layered coatings are promising environmental barrier coatings, but its molten salt corrosion mechanism is unclear. In this work, Yb2SiO5/mullite bi-layered coatings are fabricated by combining plasma spraying and dip-coating techniques. Residual stresses in the coatings caused by thermo-mechanical interaction are investigated by a nondestructive Raman spectrum method under high-temperature molten salt corrosion. In the as-deposited coatings, the stress in the mullite layer is compressive and the value near Si3N4 substrate is minimum. During high-temperature corrosion test, the residual stress near mullite-substrate interface changes sharply while the stress near mullite-Yb2SiO5 interface is concentrated without large fluctuation. An interfacial phase, YbAlO3, which is formed because of the inter diffusion of Al in the mullite layer and Yb in the Yb2SiO5 layer, causes the stress concentration. The change of SiO2 component in the mullite layer leads to the sharp change of residual stress near the mullite-substrate interface.
Oxidation Resistance of ZrB2-SiC-WSi2 Coating Prepared by Vacuum Plasma Spraying
Authors: Li Chong , Niu Ya Ran , Liu Tao , Zhao Jun , Zheng Xue Bin , Ding Chuan Xian
Published: August 2018

ZrB2-SiC-WSi2 (labeled as ZSW) coating and ZrB2-SiC (labeled as ZS) coating were fabricated by vacuum plasma spray technique. The microstructure and composition of as-sprayed coating were detected through X-ray diffraction (XRD), scanning electron microscope (SEM) and X-ray energy dispersive spectrometry (EDS). Oxidation behaviors and microstructure evolution of these coatings were evaluated at 1500 °C in air and compared with ZrB2-SiC coating. The results showed that the addition of WSi2 improved the oxidation resistance of the ZrB2-SiC coating. There was more liquid formed on the ZSW coating surface. Some bubbles were also observed on the coating surface, which might be resulted from gas formation. It can be concluded that the amount of WSi2 had great influence on its function in ZrB2-SiC system.
Oxidation Behavior of Cr1-xAlxN Coatings Deposited by Closed Field Unbalanced Magnetron Sputtering at 800°C
Authors: Chang Wei Jie , Zhang Hao , Wang Yu Long , Luo Chen Gang , Li Xiang Rui , Duo Shu Wang
Published: August 2018

CrN coating possesses high strength, hardness and good resistance to friction. In order to further improve the performance of CrN coating, especially the high temperature resistance, a series of Cr1-xAlxN coatings with different Al content were deposited on the surface of 316 stainless steel by closed field unbalanced magnetron sputtering (CFUBMS). The microstructure, mechanical properties of Cr1-xAlxN coatings were investigated by XRD, FESEM/EDS and microhardness tester, respectively. The oxidation behaviors of Cr1-xAlxN coatings at 800°C were also studied. The results showed that with the increase of Al content, the hardness of the coating increases first and then decreases, and the binding force decreases gradually, and its microstructure is gradually refined. The phases in CrAlN coatings are mainly CrN and AlN. As the amount of Al increases, the number of dense oxide films on the surface of the coating increases, increasing the antioxidant capacity of the coating.
Preparation of Al2O3-SiC Composite Powder by Carbothermal Reduction of Coal Gangue and its Influence on Properties of Blast Furnace Stemming
Authors: Wang Qi , Zhang Li Na , Min Xin , Fang Ming Hao , Wu Xiao Wen , Liu Yan Gai , Huang Zhao Hui
Published: August 2018

Al2O3-SiC composite powders are prepared by carbothermal reduction method using coal gangue as raw material and carbonaceous materials (such as coke, anthracite, and carbon black) as reducing agents. The optimum conditions are as follows: when the addition of coke or anthracite is 50%, the temperature is at 1600 °C for 5 h, and adding 50% carbon black’s best temperature is at 1600 °C for 4 h. Based on the formula of stemming used in an iron and steel factory, Al2O3-SiC-C series blast furnace stemming refractory was prepared by adding Al2O3-SiC composite powder. The results show that the addition of Al2O3-SiC composite powders has a positive influence on the apparent porosity, volume density, and bending strength of the refractory. The effect of the amount of Al2O3-SiC composite powder on the slag corrosion resistance of the blast furnace stemming refractory was also studied by the static crucible method.
Calculation of Pore Scattering in Transparent Ceramics
Authors: Hu Yue , Pan Wei
Published: August 2018

Light scattering caused by pores detrimentally affects the optical transparency of transparent ceramics. Herein, Mie theory has been used to calculate the cross-section of pore scattering in transparent ceramics, and the influence of wavelength, pore size distribution and refractive index has been discussed in detail. For wavelength between 200 nm and 2000 nm, the scattering cross-section decreases with increasing wavelength, which means that pore scattering is more detrimental to short-wavelength transparency. With ZOLD function simulating the pore size distribution inside the ceramic, it has been found that the scattering is strongest when the most-probable diameterdmequals the incident light wavelengthλ. And FWHM (full width at half maximum) parameteraalso affects the scattering cross-section.abetween 0.003 and 0.7 is necessary for obtaining high optical transparency in visible wavelength range. The method presented in this work is available for the estimation of scattering effect in different kinds of materials, which may be useful for future design of high-transparency ceramics.
Fabrication of High Dense ZnSe Ceramic by Spark Plasma Sintering: The Effect of the Powder Process Method
Authors: Gao Jia Lin , Liu Peng , Zhang Jian , Xu Xiao Dong , Tang Ding Yuan
Published: August 2018

Zinc Selenide ceramic was successfully fabricated by spark plasma sintering in the study. The ZnSe raw powders were handled with two different methods such as grinding and planetary ball milling, respectively. The relative density, microstructure and transmittance of the ZnSe ceramic sintered under the same sintering parameter with two type powders was investigated. The results shown that the performance of the powder processed by ball milling was more effective than that by grinding. Furthermore, the maximum relative density can reach 99.8% when the ZnSe powder treated by ball milling were sintered at 950 oC for 30 min with the heating rate of 10 oC/min under 100 MPa.
Fabricating Uniform Tetragonal Barium Titanate Nanocrystals via Sand Milling Assisted by an Innovative Two-Step Calcination
Authors: Zhao Qian Cheng , Wang Xiao Hui , Kim Jin Yong , Zhang Hui , Gong Hui Ling , Luo Bing Cheng , Li Long Tu
Published: August 2018

Sand-milling machine was firstly utilized to crush and disperse the raw materials. A homogenous and well-dispersed mixture of TiO2 and BaCO3 (<30nm) was obtained. The solid state reaction temperature can be reduced by 200°C for nanosized reactants compared with coarse ones. In order to increase tetragonality of nanosized BaTiO3, an innovative two-step calcination method, which includes solid state reaction process between reactants at a low temperature T1 and phase transition process at a high temperature T2, was subsequently adopted. The microstructure evolution of BaTiO3 by two-step calcination was investigated as a function of T2 and corresponding dwelling time t2. Pure-perovskite BaTiO3 nanopowders with the mean particle size as small as 75nm and tetragonality (c/a ratio) higher than 1.0096 could be fabricated by two-step calcination through altering T2 and/or its dwelling time t2.
Transparent Ultraviolet Photodetectors Based on Ga2O3 Electrospun Nanowires
Authors: Shahid Muhammad , Li Tian Jun , Zhang Meng Fei , Cheng Jing , Xing Yan , Pan Wei
Published: August 2018

Ultraviolet photodetectors (PDs) based on low-dimensional (LD) gallium oxide nanofibers were synthesized and assembled by a low cost and scalable electrospinning method. Highly uniaxially aligned nanofibers were used to assemble photodetectors. Photoconductive investigations indicate that the prepared photodetectors (PDs) are highly sensitive to ultraviolet (UV) light. The prepared photodetectors have shown a high photosensitivity (103), fast photoresponse, excellent stability, and reproducibility under the illumination of UV light 254 nm. These electrospun nanofibers have also shown a high transparency (<85%) in the visible light 400-700 nm range. The high transparency of these nanobelts demonstrates their use for invisible UV photosensors.
Synthesis and Property Investigation on the Spherical Lu3Al5O12:Tb3+ Phosphor with Green Emitting
Authors: Wang Hua Dong , Wu Tao , Zhang Jian , Wang Tao , Li Shu Qin
Published: August 2018

Spherical phosphors of (Lu1-xTbx)3Al5O12 [(Lu1-xTbx)AG] have been obtained through homogeneous precipitation method using urea as the precipitant and rare earth nitrate as mother salts. The synthesis, phase evolution and photoluminescent properties of the (Lu1-xTbx)AG phosphors were tested by XRD, FE-SEM, PLE/PL, and fluorescence decay analysis. The phase pure (Lu1-xTbx)AG garnets were formed at 1100 °C or higher temperatures. The phosphors exhibited strong green emissions at ~545 nm (the 5D4→7F5 transitions of Tb3+) under ~276 nm excitation. The CIE chromaticity coordinates and color temperature were determined to be (~0.36, ~0.56) and ~5100 K, respectively. The intensity of 545 nm emission increased with the Tb3+ content increasing to 7 at%, and then gradually decreases owing to the concentration quenching. The lifetime of 545 nm emission decreases at a higher Tb3+ addition. The spherical (Lu1-xTbx)AG garnet phosphors developed in the this work were expected to be widely used in lighting and displaying areas.
Effect of Rare Earth Doping on Electrochemical Properties of Fe2O3 Nanoparticle for Supercapacitor
Authors: Yan Wei Kang , Bi Jian Qiang , Wang Wei Li
Published: August 2018

Fe2O3 nanoparticle was prepared by a hydrothermal method, and the influence of rare earth elements (Y3+, Nd3+ and La3+) on the electrochemical performance was studied. The crystal structure and microstructure of the synthesized lithium zinc ferrite were characterized by X-ray diffraction (XRD),scanning electron microscopy (SEM). The results show that the powder is well crystallized and the particles are mostly irregular.The electrochemical property was characterized via cyclic voltammetry (CV) and constant current charge-discharge method. The capacitance of the Fe2O3 nanoparticle is 258.3 F/g, 342.7 F/g after doping Y3+ ,337.1 F/g after doping Nd3+and 331.2 F/g after doping La3 +. The results show that the rare earth elements (Y3+, Nd3+ and La3+) after the specific capacitance has increased, more suitable for super capacitor materials.