bluuebunny/crossref_metadata_2025 huggingface dataset:
The Influence of Cu/Ti Overlapping Region Microstructures on the Mechanical Tensile Properties of the Joint via Friction Stir Lap Welding
Authors: Li Bo , Shen Yi Fu , Yao Lei
Published: January 2017

The investigation on friction stir lap welding (FSLW) of dissimilar Cu and Ti is reported in this research, aiming to achieve a reliable solid-state joining and effectively control the intermetellic (IMC) formation at the lapping Cu/Ti dissimilar welded interfaces. Following the previous process optimization of the FSLW tool rotation speed and downward plunge value of the tool pin into the lower Ti sheet, the tool travel speed was further tailored for a defect-free joint. No significant Ti-Cu IMC was founded in the generated joints. After the analyses of tensile properties of the FSLW joints, the so-called mechanical locking effect of the Cu/Ti alternate band structure was further elucidated. The composite-like structure played a so-called mechanical locking effect on the Cu/Ti lap joints. The fracture resistant strength of the joint reached 95% of that of the used parent copper.
Study on the Stabilization/Solidification of Lead-Contaminated Soil Using Alkali-Activated Cementing Materials with Rich-Silicon Materials
Authors: Zhou Min , Wu Shu Yan , Lv Yi , Wang Wei Xin , Hou Hao Bo
Published: January 2017

In this study, the stabilization/solidification of lead in soils using alkali-activated cementing materials with rich-silicon materials was investigated. The artificial Pb-polluted soil with 500mg/kg lead was treated using fly ash-, silica fume-and rice husk ash-based cementitious materials, respectively, at the dosages 25%. The effectiveness of treatment was assessed with unconfined compressive strength (UCS) and the toxicity characteristic leaching procedure (TCLP) after curing for 14 and 28 days. Overall, the UCS results showed that the UCS values are above the USA EPA’s recommended value of 0.35 MPa. The TCLP results indicated that the Pb concentrations extracted from soils amended with 25% cementitious materials after 14 and 28 days are near 0.25mg/L, far below 5mg/L (the TCLP regulatory limit). And the XRD results showed the immobilization of lead were due to the formation of PbSiO3, the sorption of C-S-H.
The Valence Electron Structure of High-Entropy Alloys
Authors: Cheng Bo , Li Yun Kai , Hou Gui Qin
Published: January 2017

Empirical Electron Theory in Solids and Molecules (EET) was used to analyze the valence electron structure of ZrTiHfVNb, ZrTiHfVTa and ZrTiHfNbMo high-entropy alloys. The parameters characterizing the valence electron structure of high-entropy alloys were calculated, which were used to discuss the hardness and melting temperature of high-entropy alloys. The results show that the hardness of high-entropy alloys is positively correlated to the shared electron pair number in valence electron structure. The theoretical melting temperatures of high-entropy alloys were predicted by the parameters characterizing the valence electron structure.
Experimental Study on the Emergency Disposal Agent for Methanol Leakage
Authors: Zhang Tong , Wang Shou Zhong , Dong Chun Hong
Published: January 2017

According to the characteristics of methanol leakage hazard, a new kind of foam decontamination agent was prepared and tested. Experiments were conducted in a laboratory-scale apparatus, where the effect of composition and amount on the decontamination performance of the foam was studied in detail. Results showed that the decontaminating efficiency of the foam was above 92% with the volume of foam agent sprayed 3 times of the methanol leaked. Moreover, the thick foam layer could stably cover the liquid methanol for a long time, efficiently inhibiting the volatilization of methanol vapor. Such performance of the foam agent was much superior to that of the commonly used water mist and activated carbon powder. The results are expected to provide useful experimental data and theoretical basis for the practical emergence disposal of methanol leakage.
Study on the Performances Properties of Medical Pure Magnesium by Ion Implantation of Nitrogen
Authors: Tang De Weng , Zhang Wen Ming , Zhao Rui Lan , Lv Xi Jian
Published: January 2017

To improve medical pure magnesium corrosion and wear resistance, the advanced plasma implantation technology were used to implanted medical pure magnesium with nitrogen ions under certain conditions, obtaining a certain depth of nitrogen ion implantation layer, and to study the surface properties of the implantation layer. The sample after ion implanted, the surface morphology, phase composition were analyzed, and have electro chemical corrosion tests, friction and wear tests, the results showed that: pure magnesium by nitrogen ion implantation, can be obtained a surface organizations which whole flat, compact, no surface cracks and holes; the surface implantation layer mainly composed of Mg and MgO, also found a small amount of Mg3N2, which is also the main reason for corrosion and wear resistance improved; compared to pure magnesium base, nitrogen ion implantation (process conditions: implantation energy: 40KeV, implantation dose: 3×1017ions/cm2, control temperature: 200°C) improved the corrosion resistance of the sample, but not obvious, about 1.2%; however, the friction coefficient decreased significantly, approximately 61%, the amount of wear also reduced significantly, about 74%, this means that, its wear resistance has been improved significantly. This study provides a reference to improve the surface properties of pure magnesium and be learned to develop a more reasonable parameters for further study of medical pure magnesium by ion implantation of nitrogen.
The Effects of Substitution of Nd by Gd on the Magnetic Properties of Melt-Spun Nd-Fe-B
Authors: Xu Xiao Ling , Cheng Gang , Du Yu Song , Li Lin , Huo Jian Jun
Published: January 2017

In this work, the effects of substitution of Nd by Gd on the magnetic properties of Nd-Fe-B magnets were investigated. The results demonstrate that the size of grain decreases with the addition of Gd element. The Curie temperatures (Tc) are found to improve with the increase in Gd content, which means that the thermal stability of the magnets is enhanced. The coercivity and saturation magnetization decrease with the increase in Gd content due to the low magnetocrystalline anisotropy and saturation magnetization of Gd2Fe14B.
Microstructure and Magnetic Properties of (Nd0.7Pr0.15RE0.15)2.28Fe13.58B1.14 (RE=La, Ce, Y) Alloys
Authors: Ma Jie , Wang Jiang , Rong Mao Hua , Rao Guang Hui , Zhou Huai Ying
Published: January 2017

In this work, the microstructure, crystal structure and magnetic properties of (Nd0.7Pr0.15RE0.15)2.28Fe13.58B1.14 (RE=La, Ce, Y) alloys prepared by arc-melting were investigated experimentally. The experimental results show that all alloys annealed at 1173 K for 360 hrs contain the isotropic Nd2Fe14B structure phase. The coercivities (Hc) of (Nd0.7Pr0.15RE0.15)2.28Fe13.58B1.14 (RE=La, Ce, Y) melt-spun ribbons are 12.3 kOe, 13.2 kOe, 8.5 kOe, and the Curie temperatures (Tc) of annealed (Nd0.7Pr0.15RE0.15)2.28Fe13.58B1.14 (RE=La, Ce, Y) alloys are 569 K, 552 K and 576 K, respectively. Meanwhile, the remanences (Br) of (Nd0.7Pr0.15RE0.15)2.28Fe13.58B1.14 (RE=La, Ce, Y) melt-spun ribbons are about 67 emu/g, 74 emu/g and 72 emu/g, respectively. It was indicated that the coercivity, remanence and Curie temperatures of (Nd0.7Pr0.15RE0.15)2.28Fe13.58B1.14 alloys are dependent on light rare earth elements.
A Novel Strategy for Preparation of Cu2(MII)(MIV)S4 Thin Films for Solar Cell: Sulfurization of Mixed Metal Oxides Precursor Synthesized by Combustion Method
Authors: Jin Xin , Zhang Li Jian , Wu Chun Yan , Zhang Yan , Jiang Guo Shun , Liu Wei Feng , Zhu Chang Fei
Published: January 2017

In this study, a novel strategy for preparation of Cu2(MII)(MIV)S4 thin films was creatively proposed. Three light absorption materials Cu2MnSnS4, Cu2ZnSnS4 and Cu2ZnGeS4 were successfully synthesized based on combustion method. It was found that the combustion synthesized powder is mainly consist of several metal oxides. The band gap energy of Cu2MnSnS4, Cu2ZnSnS4 and Cu2ZnGeS4 are determined to be 1.3 eV, 1.49 eV and 2.15 eV, respectively, showing a promising application on thin film solar cells. According to our experiment results, the combustion method was confirmed to be an efficient tool to synthesize various Cu-based absorber materials by using a post-sulfurization process, which provides a new view for fabrication of high-efficient low-cost photovoltaics.
Study of Mechanism of Failure and Wear of Multi-Layered Composite Nano-Structured Coating Based on System Ti-TiN-(ZrNbTi)N Deposited on Carbide Substrates
Authors: Vereschaka Alexey Anatolevich , Mokritskii Boris Ya. , Sitnikov Nikolay N. , Oganyan Gaik V. , Aksenenko Anatoliy Y.
Published: January 2017

The aim of this paper is to study physical and chemical properties of nanostructured multi-layered composite coating based on three-layered architecture of Ti-TiN-(ZrNbTi)N, deposited to a carbide substrate, as well as to study the mechanism of wear and failure of carbide tools with coatings under the conditions of stationary cutting. The coating obtained by the method of filtered cathodic vacuum arc deposition (FCVAD). The microstructure of carbide cubstrate with coating on transverse cross-section were investigated, as well as its hardness, strength of the adhesive bond to the substrate, chemical composition and phase composition. The studies of cutting properties of the carbide inserts with developed coating was conducted on a lathe in longitudinal turning of steel C45 (HB 200). Analysis of mechanisms of coated tool wear and failure was carried out, as well as - the study of processes of diffusion and oxidation in the surface layers of the coated substrate.
A Mini-Review on the Progress of Spherical Bacterial Cellulose Production
Authors: Brandes Ricardo , Carminatti Claudimir , Mikowski Alexandre , Al-Qureshi Hazim , Recouvreux Derce
Published: January 2017

Bacterial cellulose (BC) is a polymer produced by some bacteria and it is highly pure when compared to plant cellulose. Its structure and properties are unique, which makes it a material of a large commercial interest due to its broad potential of applications. The biosynthesis of BC may be carried out in two ways either static or agitated culture. Static culture usually generates BC membranes whereas agitated tends to produce spherical shapes. The production in agitated culture often enables an increase of yield for cellulose production. However, it provides a material with lower mechanical properties compared to static culture. The processing parameters and the phenomena governing the formation of BC in agitated cultivation have not fully established. A greater understanding of the phenomena and parameters inherent in the production of BC in agitated culture is necessary to achieve a technological progress. Some limitations concerning molecular weight control and BC structure made in agitated culture can improve with a better understanding of the culture conditions and the biosynthesis evolution. The ex-situ or in-situ insertion of additives may be performed to increase some specific properties of BC over agitated culture. Thus, the principal objective of this work is to discuss and provide a broad literature review on the techniques of BC production by agitated culture.
Characterization of Al2O3/Water Nanofluid through Shell and Tube Heat Exchangers over Parallel and Counter Flow
Authors: Nallusamy S.
Published: January 2017

Nanotechnology has become one of the fastest growing scientific and engineering disciplines. Nano fluids have been established to possess enhanced thermal and physical properties such as thermal conductivity, thermal diffusivity, viscosity and convective heat transfer coefficients. The aim of this research article is to analyze the overall heat transfer coefficient by doing an experimental investigation on the convective heat transfer and flow characteristics of a nano fluid. In this research, an attempt was made for the nano fluid consisting of water and 1% volume concentration of Al2O3/water Nano fluid flowing in a parallel flow, counter flow in shell and tube heat exchanger under laminar flow condition. The 50nm diameter Al2O3nanoparticles are used in this investigation and was found that the overall heat transfer coefficient and convective heat transfer coefficient of nano fluid to be slightly higher than that of the base liquid at same mass flow rate and inlet temperature. Three samples of dissimilar mass flow rates have been identified for conducting the experiments and their results are continuously monitored and reported. The experimental analysis results were concluded that the heat transfer and overall heat transfer coefficient enhancement is possible with increase in the mass flow rate of fluid and Al2O3/water nano fluid on a comparative basis.
Controlling the Size of Interior Core of Silicon Nanowires
Authors: Soam Ankur , Dusane Rajiv
Published: January 2017

As the physical and electrical properties of silicon nanowires (SiNWs) are determined by their dimension, it is necessary to control their dimension to integrate them in a device. SiNWs were synthesized via Vapor-Liquid-Solid (VLS) mechanism in hot-wire chemical vapor process (HWCVP) technique using silane as a Si source and Sn as a catalyst. Different sizes of nano-template have been made by depositing of different amount of Sn using thermal evaporation method. The size of nano-template is found to be increased with the quantity of Sn. The diameter of resulted SiNWs depends on the size of the nano-template and it increases with the nano-template size. However, the diameter of SiNWs is found to be much larger than the used nano-template which is due to the deposition of silicon film on the sidewalls of the growing SiNWs. It is demonstrated here that the diameter of the interior core of SiNWs can be controlled desirable by adjusting the size of the nano-template.
Effect of Current Mode Signaling in Carbon Nanotube On-Chip Interconnect
Authors: Murugeswari P. , Kabilan A.P. , Jayanthi V.E.
Published: January 2017

A novel signaling technique for on-chip carbon nanotube interconnect aiming a higher bitrate in the range of Terahertz (THz) with low power dissipation, employing the current mode signal transportation is proposed in this paper. The technique exploits the combined advantages of current mode signaling and carbon nanotube. Using the equivalent circuit model, the transfer function is derived for the current mode carbon nanotube interconnect. Current mode signaling through carbon nanotube interconnect is simulated in MATLAB and HSPICE to study its efficiency and performance. The results are compared with the existing voltage mode CNT, current mode copper and optical interconnect. The proposed current mode signaling for carbon nanotube interconnect achieves 102 times lesser power delay product and 90% lesser delay than voltage mode. It exhibits lesser delay, 1000 times in local and 1.2 times in global and lesser power delay product by the factor of 1000 as compared with optical interconnect.
One-Step Preparation of Green Fluorescent Graphene Quantum Dots from Petroleum Asphalt
Authors: Zhao Pin Hui , Luo Yi , Kong Ling Yun
Published: January 2017

Inherently benefiting from the natural nanosize graphene-structure in raw asphalt material. Asphalt-derived graphene quantum dots ( GQDs ) are prepared through, a facile route, one-step chemical oxidation of cheap petroleum asphalt. The as-prepared GQD sample may be well dissolved in water with a good homogeneous size at an average diameter of 2.44 nm, luminescing bright green light by excitation of 365 nm with a high quantum yield up to 16.13%. Furthermore, they are much smaller and thinner than most of the reported GQDs, presenting excellent fluorescent properties, such as excitation-tuned photoluminescence and good resistance to photobleaching. They are much smaller and thinner than most of the reported GQDs
Determining Anisotropic Young’s Modulus of Ceramic Coatings by the Relative Method
Authors: Liu Zhao , Bao Yi Wang , Nie Guang Lin
Published: January 2017

Young’s moduli of coatings in the both perpendicular and horizontal directions were evaluated by the relative method, which are determined via establishing the relationship between the uncoated specimen and the coated specimen, with different coating positions during the loading tests. Compared with other traditional methods, the relative method is much simpler in both sample pretreatment and testing device. The validity and reliability of this method has been demonstrated by the beam specimens with CVD-SiC coatings, which will be applied to establish and improve a simple and reliable evaluation system for the anisotropy of coating modulus.
Monitoring Early Hydration of Concrete with Ground Penetrating Radar
Authors: Tian Ya Po , Huang Ding Ce , Li Bo
Published: January 2017

A nondestructive method is designed and employed to monitoring the early hydration of concrete mixes. The concrete mixes are prepared with Portland cement content and water to cement ratio 0.45. Retarder (citric acid) and accelerator (triethanolamine) are used to investigate the effects on the hydration process. The variations of dielectric constant and the intensity of reflected EM wave (amplitude) are measured within the frequency of 1.5GHz using Ground Penetrating Radar (GPR) at 25 °C for each sample from 10min to 3 days after mixing with water. The electric resistivity of Portland cement paste samples is measured using a non-contacting electric resistivity device at 25 °C.The amplitude tested changes sharply corresponding to the changes of microstructure and hydration products in the concrete mix during early hydration. The relative dielectric constant decreases with increasing hydrating time. The electrical resistivity changes in agreement with the dielectric properties. The dielectric properties mainly depend on the electrical properties and water content. The test results of samples in presence of retarder and accelerator shows that the relative dielectric constant decrease slower and faster respectively compared to the plain sample. The effect of these two admixtures can be reflected on the amplitude-time curve. The results demonstrate that the dielectric properties of concrete mix can be used as an effective ways of studying the hydration progress of concrete during hydration.
The Effect of Heat Treatment on the Microstructure and Mechanical Properties of KD-II SiC Fibers in Air
Authors: Li Liang , Jian Ke , Wang Yi Fei
Published: January 2017

The polycarbosilane-derived KD-II SiC fibers were exposed in air at 1200°C for 1-100h and the effect of heat treatment on structures and properties were studied by elemental analysis, XRD, SEM and tensile test. Experimental results indicated that oxygen content, grain size of SiO2 and oxide layer thickness increased, whereas the tensile strength decreased with rising the heat treatment time. When oxidizing over 20h, the amorphous silica crystallized into α-cristobalite and there were cracks on fibers surface and the cross section formed the skin-core structure with oxide layer wrapped inner SiC fibers after oxidizing for 100h. With the same experimental condition for Hi-Nicalon SiC fibers, the differences of oxidation resistance between KD-II and Hi-Nicalon SiC fibers were compared and the oxidation degradation of KD-II SiC fibers was analyzed.
Influence of Synthesis Process on Coated Properties of Al(OH)3-Y(OH)3/ZrB2 Composite Powders
Authors: Song Jie Guang , Wang Xiu Qin , Wang Fang , Liu Ning , Li Shi Zhe , Xia Ting Ting , Yu Si Yuan , Li Shi Bin , Chen Lin
Published: January 2017

Zirconium diboride (ZrB2) ceramics with high melting point, high hardness, good electrical and thermal conductivity, good neutron control and other characteristics, can be widely used in high-temperature structural ceramics, composite materials, electrode materials. In order to improve ZrB2 difficult densification and high-temperature oxidation, the properties of coated Al (OH)3-Y(OH)3/ZrB2 composite powders prepared by co-precipitation method were investigated in this paper, The conclusions are shown that the effect of coated composite powders is getting worse with the accelerated titration rates. the coating effect will be worse with the increasing reaction time. When the concentration of mixed solution is lower, the coated effect is better. When the synthesis condition is that the titration rate of 10ml/min, and the reaction time was 1h, mixed solution ion concentration of Y3+=0.119mol/L and Al3+=0.231mol/L, the coated effect of composite powders is better.
Research on Optical Property of Black-Colored Zirconia Ceramics by Photoluminescence, Raman and Visible Reflectivity Spectra
Authors: Xu Yue , Fu Ren Li , Yang Yang , Cai Jun De , Wang Xu , Zhang Peng Fei
Published: January 2017

White color zirconia ceramics were produced by sintering of coprecipitated 3Y-TZP powder in air. By annealing at reducing atmosphere, black-color zirconia ceramics with different shades were then realized. The obtained ZrO2 samples were characterized by X-ray diffraction (XRD), UV-visible spectrum (UV-vis), photoluminescence spectra (PL) and Raman spectroscopy, respectively. UV-visible spectrum reveals that the ZrO2 samples under different reducing atmosphere have different reflectivity in 400-800nm. X-ray diffraction data confirms that the different annealing processes can result in the change of the corresponding crystal density. It is indicated that defects contributes to cell volume alteration. The PL and Raman spectra further indicates that these defects belong to oxygen vacancies and the concentration of oxygen vacancies have a strong influence on the shades of black-color zirconia ceramics.
Sintering Behavior and Microwave Dielectric Properties of Li2O-B2O3-SiO2 Doped 0.67CaTiO3-0.33LaAlO3 Ceramics
Authors: Wang Gan , Jiang Juan , Dou Zhan Ming , Ning Fan Fan , Zhang Er Tian , Zhang Tian Jin
Published: January 2017

A low temperature sintering method was used to avoid the relatively high sintering temperatures typically required to prepare 0.67CaTiO3-0.33LaAlO3 (CTLA) ceramics. 0.67CaTiO3-0.33LaAlO3 ceramics doped with Li2O-B2O3-SiO2 (LBS) were prepared by a conventional two-step solid-state reaction process. The sintering behavior, crystal structure, surface morphology, and microwave dielectric proprieties of the prepared ceramics were studied. As the small amount of LBS content increased, the small amount of liquid phase formed in an amorphous state around the surface of the grain boundaries. With the increase the content of LBS glass, the quality factor (Q×f) value decreased. CTLA+0.05 wt.% LBS ceramics sintered at 1320°C for 4h exhibited the optimal microwave dielectric properties of dielectric permittivity (εr) = 45.02, quality factor (Q×f) = 37400 GHz, and temperature coefficient of resonant frequency (τf) = 9.84 ppm/°C.
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Investigation on Synthesis and Property of Tb3+/Dy3+ Co-Doped Gd3Al5O12 Phosphor
Authors: Teng Xin , Li Bin , Li Jin Kai , Duan Guang Bin , Liu Zong Ming
Published: January 2017

The (Gd0.9-xTb0.1Dyx)3Al5O12 (x=0-0.04, GdAG:Tb3+/Dy3+) solid solution was acquired by calcining their respective precursor prepared via co-precipitation method at 1500 °C. The performance of GdAG:Tb3+/Dy3+ powders was characterized by combined technology of Fourier transform infrared absorption spectra (FT-IR), X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM) and photoluminescence (PL) spectrum analyses. The metastable Gd3Al5O12 could be stabilized by doping smaller Tb3+ ions of 10 at.%. Under the optimal UV excitation of 275 nm, the GdAG:Tb3+/Dy3+ phosphors exhibit vivid green emission at 548 nm which were attributed to the 5D4→7F5 transition of Tb3+. The CIE chromaticity coordinate was determined at (~0.32, ~0.48) with the color temperature of ~5872 K. Compared to the Dy3+-free (Gd0.9Tb0.1)AG phosphor, the emission intensity of Dy3+-doped phosphors display stronger owing to the efficient energy transfer from Dy3+ to Tb3+. The optimal amount of Dy3+ in GdAG:Tb3+/Dy3+ phosphors was determined to be ~2.5 at.% (x=0.025). The GdAG:Tb3+/Dy3+ phosphors developed in present work are expected to be a new type of green phosphor widely used in the lighting and display areas.
Effect of Preparation Process on Bending Modulus and Strength of Fiber Tubes in Radial Direction
Authors: Liu Zhao , Hu Chun Lin , Bao Yi Wang
Published: January 2017

To explore the effects of preparation process on the mechanical properties of fiber reinforced tubes in radial direction, the closed ring method was applied to assess the elastic modulus and bending strength of GFRP and CFRP prepared by winding method and pultrusion method, respectively. The results indicate that there are two obvious differences between the winding tube and the pultrusion tube: i) the elastic modulus and bending strength of the winding tube for two materials are larger than that of the pultrusion tube. It should be attributed to the position of materials under stress: the former is the fibers while the latter is the matrix; ii) the failure mode for the winding tube is brittle fracture while elastic-plastic fracture is for the pultrusion tube. Compared with other experimental methods, the results of the closed ring method are accurate and reliable, which is demonstrated to be a potential method to evaluate the mechanical properties of fiber tubes in radial direction rapidly and conveniently.
The Electrochemical Deposition of Fe Nanowires and the Influence of Current Density on the Deposition Rate
Authors: Li Ting Ting , Wang Na Na , Cheng Hai Feng , Wu Wei Zu , Li Yun
Published: January 2017

The Fe nanowire arrays are prepared by the method of alternating current, constant voltage and constant current respectively. the morphology and composition of the Fe nanowires have been characterized By scanning electron microscope (SEM), Energy-dispersive X-ray spectroscopy (EDS). The Fe nanowires growth rate with different current density was studied in anodic aluminum oxide (AAO) template for pore diameter of 85 nm, pore depth of 55 μm under the same total charge. Research shows that the deposition rate of nanowires first slightly decreased, dramatically increased again and then reduced greatly with the increase of current density from 1 mA/cm2 ~ 5 mA/cm2.
The Improvements for the Siliceous Self-Flow Castable with Adding Nano SiO2
Authors: Shi Lin , Gu Hua Zhi , Li Shuang Long , Zhu Jing Jing
Published: January 2017

In order to make up for the deficiencies due to the molding process,and improve the mechanical properties and sintering performance of self-flow castable,in this paper, we used nano SiO2 which had high surface activity as admixture. We added 0wt%, 0.1wt%, 0.2wt%, 0.3wt% of nano SiO2, and then test the linear change, Flexural strength, compressive strength,and refractoriness under load after dried at 110°Cfor 24h and heat treatment at 1400°C for 8h.The results showed that: with the increase of nano SiO2, self-flow value of self-flow castablel decreased, the flexural strength and compressive strength of the sample increased after dried at 110°C for 24 h, the strength of the self-flow castable was improved after formed.After heat treatment at 1400°C for 8h, linear change of the sample remained the same, Tridymite content, flexural strength and compressive strength increased, apparent porosity decreased, refractoriness under load lowered.
Fluoride Determination by Ion Chromatography in Fluorocarbon Coatings
Authors: Xu Dan Hua , Liu Shi Hua , Chen Peng
Published: January 2017

A quantitative ion chromatographic analytical method for the determination of fluorine in fluorocarbon coatings is proposed. The extraction of the anions from the samples was performed using potassium hydroxide after centrifugation drying to dissolved at preference temperature. Using H column to remove large amounts of potassium ions in the solution。In paper describe the observed limits of detection and of quantitation in mg kg-1 and the mean relative standard deviation in percent This method is simple operation, less interference factors, fast analysis speed, the determination results accurate and reliable, with good repeatability and reproducibility.
The Effect of Pore Structure and Water Absorption on Carbonation Resistance of Sulphoaluminate Cement Foam Materials
Authors: Zhao Dun , Li Xiao Ning , Yan Hao Chun
Published: January 2017

Researched the influence of the pore structure and water absorption on the carbonization property with sulphoaluminate foamed cement as an example. The results showed that: Under the same levels of dry density, the smaller pore size, the higher the carbonation coefficient and the integrity of pore had the same effect. After the surface water-proofing, water absorption decreased by 10% on average, the time of carbonizing completely become longer, and carbonation coefficient was increased. And put forward the methods of improving the carbonation resistance properties of sulphoaluminate cement foam materials.
Test and Optimal Design of New Type Aluminum-Plastic Composite Panel
Authors: Zhao Chun Zhi , Liu Yi , Jiang Quan , Ren Shi Wei
Published: January 2017

Aluminum-plastic composite panel is a kind of new type energy-saving and environmental-friendly curtain wall decorative material, and is widely used in building exterior wall, curtain wall board, old building reconstruction and renovation and other projects. With the development and improvement of production and application technology, the performance and functions of aluminum-plastic composite panel products have been optimized continuously; especially at present, all countries in the world have more and more strict requirements on fire safety, and the fire safety standards of buildings also have been improved continuously. In this context, all the manufacturing enterprises have been actively developing new techniques to produce new type aluminum-plastic composite panels, and have significantly improved the fireproof and flame-retardant properties of the products on the basis of ensuring all the performance levels of the products being acceptable. This paper proposes optimal design suggestions via detection analysis on three groups of aluminum-plastic composite panel samples, and is of important practical significance to the research and development of the aluminum-plastic composite panel with low-combustion-heat and flame-retardant core material.
Correction of Loss on Ignition in Slag Powder by ICP-AES
Authors: Li Man , Li Qian Nan , Wang Ming Yu , Xu Dan Hua , Yuan Qing Dan
Published: January 2017

In this work, with reference to the pretreatment method of the relevant national standard, we tested the content of SO3 in slag powder before and after burning by ICP-AES, then the result of burning loss was corrected by the content of SO3. The content of SO3 which was determined by this new method is fast and accurate, compared with the traditional method. We selected the wavelength of 182.0nm as spectral analysis of SO3. The detection limit of the method (3S) was 0.016 mg/L, the recovery rate of the sample was between 97%-104%, and the relative standard deviation (n=6) of the parallel samples was less than 1.05%.
Determination of ZrO2 and TiO2 in Alkali-Resistant Fiberglass Mesh by ICP OES
Authors: Yuan Qing Dan , Cong Lin , Chen Peng , Liu Shi Hua , Li Qian Nan
Published: January 2017

The content of ZrO2 and TiO2 in alkali-resistant fiberglass mesh was determined by ICP OES. The sample was pretreated by acid-soluble and alkali-fusion methods. Compared with the results of standard method, the results showed that the method can be used for the determination of ZrO2 and TiO2 in alkali-resistant fiberglass mesh. Standard solutions were prepared based on the content of elements. The best analysis of spectral lines was determined for each element. Blank solution was prepared and injected ten times continuously. The corresponding concentration of three times of standard deviation (3S) was used to calculate the detection limit of the method, and the detection limit was from 0.0018% to 0.0047%. The corresponding concentration of ten times of standard deviation (10S) was used to calculate the quantitation limit of the method, and the limit of quantitation was from 0.0060% to 0.016%. Six repeated tests were performed on two samples, and the relative standard deviations (RSDs (n=6)) of the test were from 0.60% to 0.78%. Compared to standard method, absolute error was less than 0.2% and the relative error was less than 2.0%. The results showed that the method can be used for simultaneous determination of ZrO2 and TiO2 in alkali-resistant fiberglass mesh., with fast analysis and reliable results.
Measurement of Multilayer Film Thickness Using X-Ray Fluorescence Spectrometer
Authors: Zhang Lei , Li Man , Li Hai Jian , Song Xin
Published: January 2017

Energy dispersive X-ray fluorescence spectrometry (EDXRF) allows a rapid determination of the concentration of elemental constituents or the thickness of thin film, it has been widely used in the industry of thin film thickness. But for multilayer film, especially the middle layer, with the absorption and enhance effect of other layers, the thickness and intensity of the middle layer is not a linear relationship. This paper reports a quantitative analysis of multilayer film thicknesses based on the use of EDXRF and fundamental parameters method. The thickness of multilayer film can be easily determined with the CTCFP software because it requires a minimum number of pure elementals only. Analysis of double-layer thin films using the CTCFP software shows that the inter-element and inter-layer X-ray absorptions and enhancements in a specimen have been determined properly. Results obtained on the standards confirmed the accuracy of the method.
Rheological Measurement of In Situ Preheating Polycarbosilane Melt
Authors: Huang Liu Ying , Zhu Zi Qing , Cheng Xuan , Zhang Ying
Published: January 2017

Rotational rheometer has been widely used in studying rheological properties of materials. However, the conventional rheological measurements may not be applicable for some non-traditional materials with characteristic properties. Polycarbosilane (PCS) is an oligomer and in the form of solid state at room temperature. A large amount of air bubbles are evolved during the heating process of PCS, which is extremely harmful for rheological measurements of PCS melt and detrimentally influences the accuracy of rheological data. In this work, a series of PCS raw samples were pretreated with different heating processes by the advanced rheometric expansion system at 315°C before the rheological measurements at 295°C. The softening point temperatures and molecular weight distributions of different PCS samples were obtained before and after the preheating processes. The experimental data collected with the in-situ preheating and ex-situ preheating for 1 h were compared.
Determining Zero Shear Viscosity of Polycarbosilane Melts
Authors: Zhu Zi Qing , Huang Liu Ying , Cheng Xuan , Zhang Ying
Published: January 2017

As an important precursor in preparation of silicon carbide ceramic fibers by polymer precursor-derived method, it is very difficult to find the zero shear viscosity through the conventional steady test for the oligomer-like polycarbosilane (PCS) because of the possible oxidation and a prolonged time required to attain a steady state of the samples. In this work, a steady test and a series of transient tests were performed for the PCS melts. The limitation of the steady test is discussed. An averaging method based upon data from the transient tests is developed to determine the zero shear viscosity for the melt. The reliability of the results from the method is discussed and the zero shear viscosity of the pretreated PCS melt was obtained.
The Design and Evaluation of an Integrated Wire Bond-less Power Module using a Low Temperature Co-fired Ceramic Interposer
Authors: Seal Sayan , Glover Michael D. , Mantooth H. Alan
Published: January 2017

This article presents the plan and initial feasibility studies for an Integrated Wire Bond-less Power Module. Contemporary power modules are moving toward unprecedented levels of power density. The ball has been set rolling by a drastic reduction in the size of bare die power devices owing to the advent of wide bandgap semiconductors such as silicon carbide (SiC) and gallium nitride. SiC has capabilities of operating at much higher temperatures and faster switching speeds compared with its silicon counterparts, while being a fraction of their size. However, electronic packaging technology has not kept pace with these developments. High-performance packaging technologies do exist in isolation, but there has been limited success in integrating these disparate efforts into a single high-performance package of sufficient reliability. This article lays the foundation for an electronic package designed to completely leverage the benefits of SiC semiconductor technology, with a focus on high reliability and fast switching capability. The interconnections between the gate drive circuitry and the power devices were implemented using a low temperature cofired ceramic interposer.
Adaption of Functional Ceramic Materials for the Laser Sintering Process in Integrated Sensor Applications
Authors: Gradmann Rena , Seuthe Thomas , Vedder Christian , Eberstein Markus , Partsch Uwe
Published: January 2017

The ceramic thick film technology allows the buildup of miniaturized and robust integrated multilayer circuits and sensors by means of sequential screen printing and firing of different functional materials. However, the manufacturing of integrated electronics does not succeed if the components are temperature sensitive or too large for the process in a sintering furnace. At present, large components like wind power rotors, axles, or roller bearings are monitored by vulnerable hybrid sensor systems. To implement the advantages of integrated devices, such as the direct surface contact and the high thermomechanical stability, functional ceramic-based materials are adapted or newly developed to accommodate the requirements of laser sintering techniques of printed sensor layers on structural components. In a first approach, first screen-printed thick films on steel components are investigated. The defect-free densification of functional layers crucially depends on the particular material composition and adapted laser treatment. A first generation of functional layers is presented, comprising insulating, conductive, and resistive electrical materials. The films are tested in demonstrator setups and show functional properties comparable with those of the furnace sintering technology. Herein, future aspects of material optimization and the adaption to specific application requirements are discussed.
Radical chemistry at a rural site (Wangdu) in the North China Plain: observation and model calculations of OH, HO2 and RO2 radicals
Authors: Tan Zhaofeng , Fuchs Hendrik , Lu Keding , Hofzumahaus Andreas , Bohn Birger , Broch Sebastian , Dong Huabin , Gomm Sebastian , Häseler Rolf , He Lingyan , Holland Frank , Li Xin , Liu Ying , Lu Sihua , Rohrer Franz , Shao Min , Wang Baolin , Wang Ming , Wu Yusheng , Zeng Limin , Zhang Yinsong , Wahner Andreas , Zhang Yuanhang
Published: January 2017

Abstract. A comprehensive field campaign was carried out in summer 2014 in Wangdu, located in the North China Plain. A month of continuous OH, HO2 and RO2 measurements was achieved. Observations of radicals by the laser-induced fluorescence (LIF) technique revealed daily maximum concentrations between (5–15)  × 106 cm−3, (3–14)  × 108 cm−3 and (3–15)  × 108 cm−3 for OH, HO2 and RO2, respectively. Measured OH reactivities (inverse OH lifetime) were 10 to 20 s−1 during daytime. The chemical box model RACM 2, including the Leuven isoprene mechanism (LIM), was used to interpret the observed radical concentrations. As in previous field campaigns in China, modeled and measured OH concentrations agree for NO mixing ratios higher than 1 ppbv, but systematic discrepancies are observed in the afternoon for NO mixing ratios of less than 300 pptv (the model–measurement ratio is between 1.4 and 2 in this case). If additional OH recycling equivalent to 100 pptv NO is assumed, the model is capable of reproducing the observed OH, HO2 and RO2 concentrations for conditions of high volatile organic compound (VOC) and low NOx concentrations. For HO2, good agreement is found between modeled and observed concentrations during day and night. In the case of RO2, the agreement between model calculations and measurements is good in the late afternoon when NO concentrations are below 0.3 ppbv. A significant model underprediction of RO2 by a factor of 3 to 5 is found in the morning at NO concentrations higher than 1 ppbv, which can be explained by a missing RO2 source of 2 ppbv h−1. As a consequence, the model underpredicts the photochemical net ozone production by 20 ppbv per day, which is a significant portion of the daily integrated ozone production (110 ppbv) derived from the measured HO2 and RO2. The additional RO2 production from the photolysis of ClNO2 and missing reactivity can explain about 10 % and 20 % of the discrepancy, respectively. The underprediction of the photochemical ozone production at high NOx found in this study is consistent with the results from other field campaigns in urban environments, which underlines the need for better understanding of the peroxy radical chemistry for high NOx conditions.
UCLALES–SALSA v1.0: a large-eddy model with interactive sectional microphysics for aerosol, clouds and precipitation
Authors: Tonttila Juha , Maalick Zubair , Raatikainen Tomi , Kokkola Harri , Kühn Thomas , Romakkaniemi Sami
Published: January 2017

Abstract. Challenges in understanding the aerosol–cloud interactions and their impacts on global climate highlight the need for improved knowledge of the underlying physical processes and feedbacks as well as their interactions with cloud and boundary layer dynamics. To pursue this goal, increasingly sophisticated cloud-scale models are needed to complement the limited supply of observations of the interactions between aerosols and clouds. For this purpose, a new large-eddy simulation (LES) model, coupled with an interactive sectional description for aerosols and clouds, is introduced. The new model builds and extends upon the well-characterized UCLA Large-Eddy Simulation Code (UCLALES) and the Sectional Aerosol module for Large-Scale Applications (SALSA), hereafter denoted as UCLALES-SALSA. Novel strategies for the aerosol, cloud and precipitation bin discretisation are presented. These enable tracking the effects of cloud processing and wet scavenging on the aerosol size distribution as accurately as possible, while keeping the computational cost of the model as low as possible. The model is tested with two different simulation set-ups: a marine stratocumulus case in the DYCOMS-II campaign and another case focusing on the formation and evolution of a nocturnal radiation fog. It is shown that, in both cases, the size-resolved interactions between aerosols and clouds have a critical influence on the dynamics of the boundary layer. The results demonstrate the importance of accurately representing the wet scavenging of aerosol in the model. Specifically, in a case with marine stratocumulus, precipitation and the subsequent removal of cloud activating particles lead to thinning of the cloud deck and the formation of a decoupled boundary layer structure. In radiation fog, the growth and sedimentation of droplets strongly affect their radiative properties, which in turn drive new droplet formation. The size-resolved diagnostics provided by the model enable investigations of these issues with high detail. It is also shown that the results remain consistent with UCLALES (without SALSA) in cases where the dominating physical processes remain well represented by both models.
EURODELTA-Trends, a multi-model experiment of air quality hindcast in Europe over 1990–2010
Authors: Colette Augustin , Andersson Camilla , Manders Astrid , Mar Kathleen , Mircea Mihaela , Pay Maria-Teresa , Raffort Valentin , Tsyro Svetlana , Cuvelier Cornelius , Adani Mario , Bessagnet Bertrand , Bergström Robert , Briganti Gino , Butler Tim , Cappelletti Andrea , Couvidat Florian , D'Isidoro Massimo , Doumbia Thierno , Fagerli Hilde , Granier Claire , Heyes Chris , Klimont Zig , Ojha Narendra , Otero Noelia , Schaap Martin , Sindelarova Katerina , Stegehuis Annemiek I. , Roustan Yelva , Vautard Robert , van Meijgaard Erik , Vivanco Marta Garcia , Wind Peter
Published: January 2017

Abstract. The Eurodelta-Trends multi-model chemistry-transport experiment has been designed to facilitate a better understanding of the evolution of air pollution and its drivers for the period 1990–2010 in Europe. The main objective of the experiment is to assess the efficiency of air pollutant emissions mitigation measures in improving regional scale air quality. The present paper formulates the main scientific questions and policy issues being addressed by the Eurodelta-Trends modelling experiment with an emphasis on how the design and technical features of the modelling experiment answer these questions. The experiment is designed in three tiers with increasing degree of computational demand in order to facilitate the participation of as many modelling teams as possible. The basic experiment consists of simulations for the years 1990, 2000 and 2010. Sensitivity analysis for the same three years using various combinations of (i) anthropogenic emissions, (ii) chemical boundary conditions and (iii) meteorology complements it. The most demanding tier consists two complete time series from 1990 to 2010, simulated using either time varying emissions for corresponding years or constant emissions. Eight chemistry-transport models have contributed with calculation results to at least one experiment tier, and three models have – to date – completed the full set of simulations (and 21-year trend calculations have been performed by four models). The modelling results are publicly available for further use by the scientific community. The main expected outcomes are (i) an evaluation of the models performances for the three reference years, (ii) an evaluation of the skill of the models in capturing observed air pollution trends for the 1990–2010 time period, (iii) attribution analyses of the respective role of driving factors (emissions/boundary conditions/meteorology), (iv) a dataset based on a multi-model approach, to provide more robust model results for use in impact studies related to human health, ecosystem and radiative forcing.
Deduction of Reservoir Operating Rules for Application in Global Hydrological Models
Authors: Coerver Hubertus M. , Rutten Martine M. , van de Giesen Nick C.
Published: January 2017

Abstract. A big challenge in constructing Global Hydrological Models is the inclusion of anthropogenic impacts on the water cycle, such as caused by dams. Dam operators make decisions based on experience and often uncertain information. In this study information generally available to dam operators, like inflow into the reservoir and storage levels, was used to derive fuzzy rules describing the way a reservoir is operated. Using an Artificial Neural Network capable of mimicking fuzzy logic, called the Adaptive-Network-Based Inference System, fuzzy rules linking inflow and storage with reservoir release were determined for 11 reservoirs in Central-Asia, the U.S. and Vietnam. By varying the input variables of the neural network, different configurations of fuzzy rules were created and tested. It was found that the release from relatively large reservoirs was significantly dependent on information concerning recent storage levels, while release from smaller reservoirs was more dependent on reservoir inflows. Subsequently, the derived rules were used to simulate reservoir release with an average Nash–Sutcliffe coefficient of 0.81.