bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation and Thermal Stability of Quartz Fiber Reinforced Silicon Doped Aluminum Aerogel Composites
Authors: Wang K Y , Liu R X , Zhang L , Yan Y H , Sui X Y , Zhou C L , Cheng Z Q 
Published: November 2019

Abstract
Aerogel composites have drawn great attention as innovative thermal insulation materials in the field of thermal protection. In this study, quartz fiber reinforced silicon doped aluminum aerogel composites were synthesized using aluminum chloride hexahydrate (AlCl3·6H2O) and tetraethoxysilane (TEOS) co-precursor by sol-gel and supercritical fluid drying. The composites were characterized by FTIR, BET, SEM and Quartz lamp simulation test. The results showed that quartz fiber reinforced aerogel composites exhibited low density, low thermal conductivity and high temperature thermal stability. The thermal conductivities of composites increased from 0.025 W·m−1·K−1 at 150°C to 0.121 W·m−1·K−1 at 1200°C. The as-prepared composites exhibited high specific surface area (515 m2/g) with low density of 0.23 g/cm3. After being heated to 1000°C and 1200°C for 2 h, the surface area of composites reached to 217 and 68 m2/g, respectively. The aerogel composites with 25mm thickness was evaluated by quartz lamp at 1200°C for 1500 seconds. The back surface temperature of 732.7°C demonstrated excellent heat insulation performance of the aerogel composites.
Toughening of WC-Co Cemented Carbides by In-stiu Transformed Carbon Fiber
Authors: Lv Changchun , Ren Xiaoyong , Wang Chengbiao , Peng Zhijian 
Published: November 2019

AbstractWC-2Co cemented carbides toughened by in situ transformed carbon fibers were prepared by hot-press sintering at 1450°C using pre-oxidized polyacrylonitrilefibers (PANf) as the precursor. The phase composition, microstructure and mechanical properties of the samples with different added fractions of PANfwere investigated. The results show that the PANftransformed in situ into carbon fibers at 1450°C during the hot-press sintering. The formed carbon fiber could supply carbon to the sintering system, suppressing the formation of η phase and improving the relative density of the samples. With the increase in the added fraction of PANf, the Vickers hardness of the samples initially increased and then slightly decreased, reaching its maximum of about 1900 HV10with 0.5 wt.% PANf. The flexural strength and fracture toughness of the samples gradually increased from 530 MPa and 5.5 MPa·m1/2to 700 MPa and 7.5 MPa·m1/2with the increase in the added fraction of PANffrom 0 to 2 wt.%. The toughening mechanisms were cracks deflection, fiber pull-out and crack bridging.
Preparation and Thermal Properties of LaPO4 Ceramics
Authors: Dong Hongying , Chen Xiaodong , Li Jianguo , Jia Pengwei , Shuang Yingchai , Sun Qinghong , Ma Wen 
Published: November 2019

Abstract
Ceramic thermal barrier coatings (TBCs) are widely used on the gas turbine engine. As one of the candidate TBC materials, LaPO4 has attracted much attention. In the present study, the bulk LaPO4 was prepared by spark plasma sintering (SPS). The effect of different preparation conditions on the properties of the obtained LaPO4 ceramic was studied. The phase composition, microstructure, thermal expansion and thermal conductivity of the LaPO4 ceramic with heat treatment at 1450°C for different time were studied by XRD and SEM.
Study on Scintillation Properties of Several Non-fluoride Halides under Low Energy241 Am radiation
Authors: Liu S , Hou Y , Yuan H , Gui Q , Zhang C , Fang Z , Zhang M 
Published: November 2019

Abstract
A few of halide inorganic scintillation crystals have been applied as radiation detection materials and are playing important roles in nuclear medicine, high energy physics, security inspection, petroleum logging and so on, but most of them are on the way of research and development. In this paper, a series of novel halide scintillation crystals, LaBr3(Ce), LaCl3(Ce), SrI2(Eu), Cs2LiYCl6(Ce) and NaI(Tl) were studied using low energy 241Am radioactive source. The effect of reflective film thickness on low-energy ray transmittance and light output of encapsulated scintillators was investigated, Teflon thickness of 0.48 mm as reflective film is best choice to obtain higher light collection and better radiation transmittance. Among all these crystals, LaBr3(Ce) crystal has excellent energy resolution above 25keV gamma ray radiation, 9.3% at 26.34 keV, 8.4% at 59.54 keV and2.6% at 661.66 keV. Only NaI (Tl) crystal works fine below 25 keV X-rays radiation, with energy resolution of 17.68% at 13.9 keV, 14.16% at 17.8 keV and 13.42% at 20.8 keV.
Study on High-Temperature Performance of LaBr3(Ce) Scintillators
Authors: Hou Y , Liu S , Yuan H , Gui Q , Zhang C , Fang Z , Zhang M 
Published: November 2019

Abstract
In this paper, the relative light output, energy resolution and count rate of encapsulated LaBr3 (Ce) crystals were tested under the temperature from 25 °C to 175 °C using 137Cs γ radioactive source. The variation of high temperature scintillation performance of LaBr3 and NaI(Tl) crystal packages was measured and analyzed. The results show that the decline of light output of LaBr3(Ce) scintillation crystal is about 80% of that of NaI(Tl) at 175 °C. The energy resolution of LaBr3(Ce) at high temperature 175 °C is approximately 8%, which is better than the 9.9% energy resolution of NaI(Tl) scintillation crystals at room temperature 25 °C. The count rate of LaBr3(Ce) is about 5-6 times more than that of the NaI(Tl) crystal.
Compressive Creep Prediction of Corundum-Mullite Refractories Based on BP Neural Network
Authors: Deng Lina , Yi Shuai , Zeng Luju , Xue Fei , Pan Chuancai , Lin Guowei , Liu Yueqiang , Zhang Hang , Liu Xiaochen , Xie Jinli 
Published: November 2019

Abstract
Compressive creep of corundum-mullite refractories is an important performance to measure whether they can be used stably for a long time at high temperature. Therefore, a compressive creep prediction method of corundum-mullite refractory based on BP neural network is proposed. The inputs of the BP neural network are the content of Al2O3, SiO2, Fe2O3 and the time of high temperature whereas creep rate is the output. The results show that the predicted results can correspond well with the experimental results. The developed BP neural network model can efficiently and accurately predict the creep rate of corundum-mullite refractories.
Investigation on Preparation of Al0.52Zr0.48O1.74 by Microwave Pyrolysis
Authors: Gao Qiancheng , Chen Yongqiang , Zhang Ning , Chu Songzhu , Tao Zhichuang , Zhang Rui , Li Hongxia 
Published: November 2019

Abstract
ZTA composite powder was prepared by muffle furnace heating and microwave heating respectively. The effect of pyrolysis on the preparation of ZTA composite powder was investigated. Zirconium chloride (ZrOCl2•(8H2O)), aluminium sulfate and ammonia were used as raw materials. Heating temperatures were at 600°C, 700°C, 800°C, 900°C, 1000°C for 20 min respectively. XRD and SEM were carried out to characterize samples. Results showed that microwave heating completed the preparation of ZTA composite powder at an excellent lower temperature (600°C) with an optimum size (211 nm). It is mainly due to the rapid coupling between microwave and materials. The different of crystal phase of the samples by muffle furnace heating and microwave heating is mainly due to the selective response between microwave and ZTA composite materials. Microwave plasma is the main factor leading to grain refinement of ZTA ceramic powder.
Research on Corrosion Resistance of Al2O3-MgAl2O4 Refractories and SiC-MgAl2O4 Refractories to Gasifier Slag
Authors: Sun Honggang , Li Hongxia , Zhao Shixian , Du Yihao , Wang Lan , Si Yaochen 
Published: November 2019

Abstract
Spinel-containing refractory is a kind of potential chromium-free refractory for coal gasification because MgAl2O4 spinel has good slag resistance. Corundum-spinel refractories with w(Al2O3)=94%, w(MgO)=5% and SiC-spinel refractories with w(SiC)=64%, w (Al2O3)=5% were prepared. The crucible specimens were tested for slag corrosion with commercial gasifier slag at 1 500°C for 1 h in reducing atmosphere. XRD analysis were researched on the sidewall of the crucible after slag test. Microstructure and chemical composition of samples in slag corrosion zone were analyzed by SEM and EDS. The results show that the slag resistance of SiC-MgAl2O4 refractory was significantly better than Al2O3-MgAl2O4 refractory. The corundum particles were decomposed into fine particles by the slag, and the microstructure was destroyed. The oxidation of the surface of the silicon carbide particles formed a high-viscosity glass phase with the infiltrated slag, which was benefit to prevent the slag penetration into the interior. And a solid solution of (Mg, Fe)O·Al2O3 composite spinel was formed in matrix of the sample after slag penetration because MgAl2O4 absorbed FeO in the slag. It is speculated that the spinel solid solution repairs and strengthens the structure of the matrix, which improves the slag resistance.
Influence of Sucrose Binder on the Oxidation Resistance of MgO-C Refractory
Authors: Lv Zhenfei , Zhu Ling , Zhang Weiyi , Shi Tengteng , Min Xin , Wu Xiaowen , Liu Yan-gai , Fang Minghao , Huang Zhaohui 
Published: November 2019

Abstract
In this study, novel MgO-C refractories using environmentally friendly sucrose as binder were prepared. To solve the harmful effects of formaldehyde and phenolic compounds that cause serious harm to the environment and human health released during the development, production and use of phenolic resin binders for MgO-C refractories, MgO-C refractories using environmentally friendly sucrose instead of phenolic resins as binders were prepared. The phase, microstructure, oxidation resistance and the antioxidant mechanism of MgO-C refractories prepared by adding sucrose as binder at different temperatures were analyzed. The formula between the weight loss of the material and the temperature is y=1.6225x+0.215 (600°C ∼ 1200°C). The addition of aluminium resulted in the formation of Al2O3 inside the refractories. Meanwhile, MgAl2O4 crystals were synthesized by Al2O3 and MgO at high temperature. The formation of Al2O3 and MgAl2O4 played an important role in improving the oxidation resistance property of MgO-C refractories using sucrose as binder.
The Behavior of Slag Resistance of MgO-C Refractory Prepared by Sucrose as Binder
Authors: Shen Xiulin , Zhu Ling , Lv Zhenfei , Shi Tengteng , Yin Zhaoyu , Min Xin , Wu Xiaowen , Liu Yan-gai , Fang Minghao , Huang Zhaohui 
Published: November 2019

Abstract
The harmful components such as formaldehyde and phenolic compounds released during the development, production and use of MgO-C refractories prepared by using phenolic resin as a binder can cause serious harm to the environment and human health. In this paper, MgO-C refractory material with sucrose as binder and metal aluminium powder as antioxidant is prepared. Different slag temperature and time factors have a largely influence on the slag corrosion resistance of as-prepared samples. By analyzing the microstructure and composition of the samples, it is found that under the condition of constant time, the higher the temperature, the more obvious the slag corrosion phenomenon; under isothermal conditions, the longer the time, the more obvious the slag corrosion phenomenon. At the same time, it is revealed that the main corrosion process of MgO-C refractories prepared by adding sucrose as a binder is carbon oxidation and slag corrosion, which provides a theoretical basis for optimizing the slag resistance of MgO-C refractories.
Optimization and Application Technology of Reflective Foils Using in Zirconia Fiber Insulation Materials
Authors: Ai Bing , Zhang Shichao , Sun Xiankai , Sun Haoran , Chen Yufeng , Fang Kai , Yan Dachen 
Published: November 2019

Abstract
Graphite paper was used as reflective foils in the zirconia fiber insulation materials system, the effects of the number, spacing and emissivity of reflective foils on the thermal insulation properties of zirconia fiber insulation materials were studied. It was found that when the number of reflective foils is 10, interlayer spacing was 1 mm, the minimum thermal conductivity of the insulation materials was obtained. Zirconia superfine powder was used to reduce the emissivity of reflective foils, the modified reflective foils was used in the zirconia fiber insulation materials system, it was found that when the emissivity of the modified reflective foils was 0.37, the minimum thermal conductivity of insulation materials was obtained.
Erosion Mechanism of Li-Ion Batteries Cathode Materials on Si3N4-SiC and SiO2-SiC Refractories
Authors: Duan X K , Qian F , Chen Y Q , Li H X , Guo A , Si Y C , Wang X F , Liu G Q 
Published: November 2019

Abstract
The erosion mechanism of Li-ion ternary cathode material on Si3N4-SiC and SiO2-SiC refractory slabs was studied at 780 °C for 20h. The results show that the erosion resistance of Si3N4-SiC is much better than that of SiO2-SiC refractory slab after heat treatment for 20h. Erosion mechanism of the two kinds of refractory slabs are different. Inward diffusion of Li2O reacts with a large amount of SiO2 in the SiO2-SiC system. This leads to a large number of reaction products, so that the incompletely reacted SiC particles fall off along with the reaction product, causing the erosion of SiO2-SiC. For Si3N4-SiC, it is mainly because the dense SiO2 protective layer produced by oxidation of Si3N4 prevents further oxidation of Si3N4 and SiC in the system, giving the material excellent erosion resistance.
Effect of Al2O3 Particle Size on Mullite Formation by In-Situ Reaction of Aluminosilicate Castables
Authors: Guo A , Xiang Y B , Zhao S X , Si Y C , Gu Q , Wang Z M 
Published: November 2019

Abstract
The total output of unshaped refractories has been increasing in recent years due to its short production cycle, safety and energy saving, good integrity and so on. Among them, aluminosilicate castables have been widely used. In order to improve the high temperature properties of castable, Al2O3 micro powder and SiO2 micro powder are usually used. However, few researchers have reported the effect of particle size in matrix on in-situ formation of mullite. In this paper, a mass dissolution rate model and a solution nucleation shrinkage model are established based on the control of the rate of in-situ mullite formation, which takes place by the dissolution of Al2O3 to the liquid phase formed by melting of SiO2 powder containing impurities at high temperature.The results show that with the increase of Al2O3 particle size, the mass dissolution rate of independent particles was accelerated, and the nuclear shrinkage rate of Al2O3 particles decreased fastest when the particle size is 1-10μm. The dissolution rate increases with the increase of service temperature. Moreover, the complete dissolution time is shortened with the decrease of particle size of Al2O3. When the particle size is 80μm, it takes 100.31 seconds for a single particle to dissolve completely, but only 1.00 second when the particle size of Al2O3 decreases to 8μm.
Preparation of Fe-Diopside Matrix Composites from Iron Tailings and Fly Ash
Authors: Chen Yuxin , Li Baowei , Ouyang Shunli , Zhang Yuxuan 
Published: November 2019

Abstract
Iron-diopside matrix composites were prepared by using iron tailings, fly ash and iron powder as main raw materials. The samples with iron contents of 20%, 30%, 40% and 50% were investigated and compared with the basic ceramic which without iron addition. By using the methods of X-ray diffraction (XRD), scanning electron microscope (SEM), flexural strength test, the phase identification, microstructure and mechanical properties of samples were determined. The results show that the optimum addition amount of iron is 40%, under the sintering temperature1200°C and holding time 90min, the main phase of the samples is diopside, iron and a small amount of quartz. The morphology of diopside is found to be columnar crystals. The sample prepared under these conditions has the maximum flexural strength of 140MPa, which is 105.9% higher than that of the basic ceramic, with a density of 3.6g/cm3. A new method of preparing composites from solid wastes has been developed.
Tensile Properties of HDCC for Repairing Hydraulic Discharge Structures
Authors: Chen Bo , Guo Li-Ping , Chen Zheng-Kai , Ding Cong 
Published: November 2019

Abstract
To develop high ductility cementitious composites (HDCC) for repairing hydraulic discharge structures, the effect of water-binder ratio, polyvinyl alcohol (PVA) fiber content, and fly ash content on the tensile properties of HDCC was studied. The results show that with increase in water-binder ratio and/or fly ash content, the ultimate tensile strain of HDCC increases gradually, while the ultimate tensile stress and the initial cracking stress decrease. With different fiber contents, the tensile stress-strain curves of HDCC coincide in the linear elastic stage, and the initial cracking stresses are roughly the same; with increase in fiber content, the ultimate tensile strain and ultimate tensile strength increase gradually. Based on these results, the appropriate mix proportions for the HDCC material were determined for repairing hydraulic discharge structures.
Preparation and Characterization of Loess/Polyacrylamide Composites
Authors: He Yufeng , Guo Junhui , Wang Fawei , He Wenjuan , Wang Rongmin 
Published: November 2019

AbstractUsing a kind of rich soil in the world, loess soil (LS), as natural silicate minerals materials, a novel low-cost inorganic / synthetic polymer composite, loess/polyacrylamide composite (LS/PAM), was prepared by in-situ polymerization of acrylamide. The obtained LS/PAM composite was characterized by infrared spectra (IR), thermogravimetric analysis (TG) and scanning electron microscope (SEM). The results indicate that polyacrylamide (PAM) was uniformly composited with loess particles successfully.
Antimicrobial Mechanism and Biosafety Evaluation of PdO Modified WO3
Authors: Zhang Jingtao , Yuan Mingming , Du Juan , Liu Xing , Wang Xueying , Zhang Bei , Liu Shurui 
Published: November 2019

Abstract
In this study, PdO loaded WO3 composite was synthesized by precipitation method, followed by calcination. The as-synthesized composite was characterized and the photocatalytic disinfection of Escherichia coli was tested under visible light-irradiation. The characterization results showed that the PdO nanoparticles decorated on the surface of the WO3. The antibacterial test demonstrated that the as-synthesized material with 100:1 mole ratio of W:Pd and calcined at 200°C have the highest efficiency. After visible light irradiation of a short time, about 25 min, almost all of the tested E. coli cells were inactivated. Antimicrobial mechanism, revealed by scavengers of reactive oxygen species, demonstrated that the antibacterial activity was primarily due to the oxidation of photo-generated hole. And the oxidation-reduction reaction of superoxide radical and hydroxyl free radicals were assisted for the photo-disinfection of bacteria. Furthermore, the biosafety of the PdO/WO3 composite was evaluated by analysing the viability of Chinese hamster lung (V79) cells using Cell Counting Kit-8 (CCK-8).
Variable Leading Edge with Adaptive Thermal Barriers and Its Heat Transfer Behaviour
Authors: Yang X K , Xing G N , Dong Y P , Guo A R , Xu X J , Liu J C 
Published: November 2019

Abstract
At present, the hypersonic vehicles cannot be adapted to all the flight phases perfectly, and the aerodynamic heating and lift - to - drag ratio are contradictory to the shape of the vehicles. From the perspective of aerodynamic heating, a blunt shaped body is desired to reduce the heat flow of the hypersonic vehicles. However, the lift - to - drag ratio demands a sharp leading edge. In this paper, a scheme of variable leading edge which could satisfy with both the requirements of aerodynamic heating and lift-to-drag ratio was investigated, and an adaptive thermal barrier was proposed based on the features of the variable leading edge hot structure. According to the heat flux calculated from a certain trajectory by computational fluid dynamics, the heat transfer behaviour of the variable leading edge with adaptive thermal barriers was analyzed by the finite element method. The results indicated that the temperature peak of the panel reached 1428.2 K at 400 s, temperature of the adaptive thermal barriers approached 1418.4 K at 420 s, and the temperature of the internal insulation increased to 667.86 K finally. At the end of trajectory, temperature distribution in the thermal barrier and internal insulation tended to be balanced respectively, which exhibited an excellent thermal property and a promising prospect in complex environment..
Temperature Dependence of Thermal Conductivity of Boron Carbide at Intermediate and High Temperature
Authors: Liu Zhaocen , Qu Zhixue , Sun Yuan 
Published: November 2019

Abstract
The temperature dependence of thermal conductivity of boron carbide (B4C) at intermediate and high temperature was investigated in this paper. The variation of the inverse phonon mean free path with temperature as well as the density and grain size was investigated to reveal the thermal conduction mechanism of boron carbide. The results show that B4C undergoes a transition of thermal conduction mechanisms at certain temperature within the range from 473 K to 673K. The transition temperature is just half of the calculated Debye temperature of B4C. Furthermore, the transition of thermal conduction mechanisms is independent from the density and grain size.
Synthesis and Photoluminescence Properties of Water-Soluble ZnS Quantum Dots for Biomarkers
Authors: Wang Xiaoxuan , Dai Wen , Duo Shuwang , Jiang Xingyu , Wu Haoshuang , Min Wei , Zheng Ziling , Chen Zhong 
Published: November 2019

Abstract
In this work, we investigated the effects of the surfactant L-cysteine (L-cys) and folic acid (FA) on photoluminescence (PL) properties, water-solubility and biotoxicity of ZnS quantum dots (QDs). It was found that capping L-cys improved the water-solubility of ZnS QDs. The emission intensity of ZnS QDs was found to be also enhanced after capping with Lcys, The maximum emission intensity of ZnS capped with L-cys QDs was about 4.5 times stronger than the uncapped ZnS QDs. FA decreased the PL intensity of L-cys/ZnS QDs and increased water-solubility the of L-cys/ZnS QDs. The L-cys/ZnS and FA@ L-cys/ZnS quantum dots were proved to be nontoxic by the MTT assay.
The Effect of Y3+Doping on CaTiO3-LaAlO3Microwave Dielectric Ceramics
Authors: Luo Jieyu , Li Yueming , Li Zhike , Shen Zongyang , Wang Zhumei , Pu Qinheng 
Published: November 2019

AbstractCaTiO3-LaAlO3solid solution with perovskite structure has suitable relative permittivity (εr) and high quality factor (Q×f) for application as dielectric resonators, but the negative value of the temperature coefficient of resonance frequency (τf) affects its utilization. To improve dielectric properties and adjust lattice matching, Y3+ion was selected as doping element to prepare the 0.65CaTiO3-0.35(La1-xYx)AlO3(x=0, 0.02, 0.04, 0.06, 0.08 ) microwave dielectric ceramics by conventional mixed solid method. The effects of Y3+ion doping on the crystal structure and microwave dielectric properties were investigated. The results revealed that a single orthorhombic phase for all the compositions can form and the unit cell volume increases linearly with the doping contentx. Y3+ion dopant can increase the quality factor and improve the temperature coefficient of resonant frequency of 0.65CaTiO3-0.35LaAlO3ceramics. Whenx= 0.02, the optimal microwave dielectric properties ofεr=45.8,Q×f= 38957 GHz, andτf= 4×10−6/oC for the 0.65CaTiO3-0.35(La1-xYx)AlO3ceramics could be obtained, which sintered at 1500 °C for 5 h.