bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electromagnetic Wave Absorption Properties of Cobalt-Containing Polymer-Derived SiCN Ceramics
Authors: Wang Shan , Mao Junjie , Liu Yu , Lin Xiao , Sheng Mingming , Zhao Cuncai , Zeeshan Shaan , Gong Hongyu , Zhang Yujun 
Published: November 2019

Abstract
PDCs-SiCN(Co) were composed by polymer-derived technique from polysilazane and Co nano-powder. XRD, SEM and hysteresis loops patterns show that there are magnetic Co nanoparticles and newly formed magnetic Co3C particles in the compound, which makes the composite possess the required impedance matching due to the combination of dielectric and magnetic properties, thus having certain microwave absorption properties. Electromagnetic wave absorbing performance of the PDCs-SiCN (Co) ceramics was discussed when the frequency range is 2-18GHz. PDCs-SiCN (Co) ceramics mixed with 5wt% of Co nanoparticles provides best electromagnetic wave absorption performance compared with other Co contained samples when the thickness is 2mm. The minimum RL is -8.3 dB at 16.7 GHz, this means that 85% of the incident electromagnetic waves enter the material at this frequency and are further depleted. The minimum reflection loss (RL) of all samples was decreased and its corresponding frequency was also changed with the increase of sample thickness. Bandwidth of microwave absorptivity exceeding 88% (RL< -9 dB) of sample which doped with 5wt% cobalt reaches 0.35 GHz when the thickness is 7mm. The results indicated that the prepared materials have certain microwave absorption properties and have potential application prospects in the field of microwave absorbing materials.
Microstructure and Failure Behavior of Double Anti-Oxidation Coating on SiCf/SiC-CMC
Authors: Huo Yanli , Liu Hailin , Yang Taisheng , Hu Chuanqi , Huang Xiaoting 
Published: November 2019

Abstract
In this paper, BN interfacial phase was prepared on SiC fiber surface and CVD SiC gradient coating was prepared on the surface of SiCf/SiC-CMCs composite. CVD SiC coatings were fabricated by the pyrolysis of methyltrichlorosilane (MTS) in hydrogen at a low pressure of 5-10kPa. The ratio of MTS to hydrogen is 1 to 12.Oxidation behaviour is examined by placing the material with coats in air. The oxidizing temperatures were varied from 100°C to 1200°C. Optical microscope and SEM were used to observe the surface morphology and microstructure of coatings. XRD was used to characterize the phase composition. The results indicated that the Oxidation of SiC/SiC-CMC is the most serious at 800°C. Tensile strength test shows that the fracture strength of the material is the lowest and with the increase of temperature to 1200°C, the tensile strength of the material increases. Tensile strength test shows that the fracture strength of the material is the lowest and with the increase of temperature to 1200°C, the tensile strength of the material increases.
Effect of Intrinsic Structure on Stability of Domestic SiC Fiber
Authors: Chen Mingwei , Qiu Haipeng , Xie Weijie 
Published: November 2019

Abstract
The morphology, structure and composition of three different SiC fibers were studied by SEM, XRD and elemental analysis techniques in this paper. The high temperature stability of SiC fiber bundles was also characterized. The results show that the intrinsic structure of domestic first, second, and third generation silicon carbide fibers possesses large differences. The above three fibers can be classified into high oxygen high carbon, low oxygen high carbon and near stoichiometric ratio according to the composition, and classified into amorphous, low crystallinity and high crystallinity according to the structure. The difference in composition and structural characteristics of the above fibers has a great influence on the comprehensive properties of SiC fibers, especially the oxidation resistance. The high temperature oxidation resistance of the first, second and third generation SiC fibers increases gradually, which provides material basis and technical support for the preparation of ceramic matrix composites suitable for hot end components of aero-engines with different thrust-weight ratios.
Effect of Particle Size Distribution on Microstructure and Mechanical Properties of TiB2-SiC-Si Composites
Authors: Zhang Cuiping , You Tian , Zhao Ling , Xia Qian , Qin Zhaobo , Liu Yongyang , Ru Hongqiang , Wang Wei , Yue Xinyan 
Published: November 2019

Abstract
TiB2-SiC-Si ceramic composites were fabricated based on molten silicon infiltration method. The influence of particle size distribution of TiB2 on the microstructure and mechanical properties of TiB2-SiC-Si ceramic composites was studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electron universal testing machines, etc. The results showed that the composite consisted of TiB2, SiC and Si phases. The microstructure analysis showed that: the content of residual Si could be controlled less than 16 vol.% in the composite by particle size distribution. When the particle size distribution of TiB2 was 42:32:26, the TiB2-SiC-Si composite showed the optimum properties. The open porosity, volume density, Vickers-hardness, flexural strength and fracture toughness were 0.51%, 3.63 g/cm3, 17 GPa, 275 MPa and 5.7 MPa·m1/2, respectively.
Preparation and Properties of MgO-C Refractories Using Sucrose as Binder
Authors: Shi Tengteng , Zhu Ling , Yin Zhaoyu , Shen Xiulin , Lv Zhenfei , Wu Xiaowen , Min Xin , Liu Yan-gai , Fang Minghao , Huang Zhaohui 
Published: November 2019

Abstract
MgO-C refractories were prepared by using fused magnesia and flake graphite as main raw materials, adding metal aluminium powder as antioxidant, and using sucrose solution instead of phenolic resin as binder. The mechanical properties of MgO-C refractories obtained under different temperature conditions were studied and compared with those of phenolic resin bonded MgO-C refractories. The results show that CO2 and water vapor were mainly released from the solidified sucrose solution during the heating process, which can effectively solve the problem of harmful gases such as formaldehyde and phenol when the phenolic resin is heated. The MgO-C refractory material prepared by the sucrose solution as a binder has a good bonding strength after curing at 180 °C. The flexural strength and compressive strength of MgO-C refractories obtained by adding 6wt% sucrose solution are 4.90 MPa and 41 MPa. At high temperature, sucrose carbonization forms a strong carbon bonding, and the flexural strength of MgO-C refractories is 5.16 MPa and the compressive strength is 34 MPa, which is similar to the performance of the phenolic resin bonded MgO-C refractories.
In Situ Catalytic Synthesis of Si3N4 Nanowhiskers Reinforced SiC Refractories and Their High-Temperature Properties
Authors: Wang Sen , Zhang Haijun , Gu Yajun , Zhang Jun , Tian Liang , Liang Feng 
Published: November 2019

Abstract
Silicon nitride (Si3N4)–bonded silicon carbide (SiC) refractory (Si3N4-SiC) is one of the most important nonoxide refractories, but its mechanical properties still suffer from the residual Si. Herein, we report that the nitridation of Si and properties of Si3N4-SiC refractories can be improved by in-situ formed CoOx catalysts. The room-temperature modulus of rupture (MOR), high-temperature MOR, thermal shock resistance, and oxidation resistance of as-prepared Si3N4(w)-SiC refractories with catalysts were investigated. The results showed that CoOx catalysts enhanced the nitridation of Si powders and promoted the formation of Si3N4 whiskers. The high-temperature MOR at 1573 K of as-prepared refractories was improved by 30%, compared with samples without catalysts. Moreover, the thermal shock resistance and oxidation resistance of the former was remarkably higher than that of the latter. The improvement was attributed to in-situ formation of Si3N4 whiskers network structure in the samples due to the catalytic effects of CoOx catalysts.
Effect of Cu/Si Additive on the Microstructure of Pyrolysis Carbon Derived from Phenolic Resin
Authors: Jiang Pengcheng , Wang Zhoufu , Wang Xitang , Liu Hao , Ma Yan 
Published: November 2019

Abstract
Phenolic resin has been widely applied as a carbonaceous binder in the field of carbon composites and carbon materials. The microstructure of pyrolysis carbon that derived from carbonaceous binders played an important role in the properties of carbon-containing refractories. In this study, the effects of copper and silicon on the pyrolysis behavior of phenolic resin and the microstructure of the pyrolysis carbon were investigated by using thermosetting phenolic resin as raw material, and using silicon powder (99%, 200 mesh) as well as copper nitrate (AR, w(Cu(NO3)2)⩾99%) as additives. The results showed that the copper nano-particles in-situ formed from copper nitrate could be served as catalyst in the pyrolysis process of resin. Catalytic synthesis of carbon nanofibers could improve the degree of carbonization with pyrolysis carbon microstructure at low temperature (below 800 °C). The carbon nanofibers had lamellar structure and layered stacking characteristic. Silicon carbide whiskers were produced by Cu-doping phenolic resin with copper and silicon at 1400 °C.
Research on the Thermal Insulation Performance of High Temperature Gradient Composite Insulation Material
Authors: Sun Xiankai , Zhang Shichao , Sun Haoran , Fang Kai , Yan Dachen , Chen Yufeng 
Published: November 2019

Abstract
In this study, the high temperature gradient composite insulation material (SGIM) was prepared by using zirconia fiber and carbon fiber (CZ), high temperature phase-change material (HPCM), microcellular thermal insulation material of calcium silicateas (CS/AS), insulation material of nano-silica(NP) and radiation shielding material as raw materials. The thermal insulation performance was simulated by using the finite element software. The heat insulation performance of the material was tested by oxy-acetylene ablation experiment. The thickness of the insulation material was also set to 32 mm. The temperature of hot surface was controlled at 2000°C. After 600 seconds, the material of cold temperature was 54°C. The excellent performance of SGIM insulation is demonstrated.
Uniaxial Tensile Properties of High Ductility Cementitious Composites with Sulphoaluminate Cement
Authors: Chen Bo , Guo Li-Ping , Ding Cong 
Published: November 2019

Abstract
This study evaluates the effect of sulphoaluminate cement content on the performance of high ductility cementitious composite (HDCC) as repair material. To prepare the HDCC, Portland cement was partially replaced with 10%, 15%, or 20% rapid hardening sulphoaluminate cement. The compressive and flexural strength developments and tensile properties of the sulphoaluminate cement containing HDCC were investigated. The microscopic mechanism by which sulphoaluminate cement affects the macroscopic performance of HDCC was examined by scanning electron microscopy. Before 14 d, the mechanical properties were directly proportional to the sulphoaluminate cement content, but at 28 d, the sulphoaluminate cement content exerted no obvious effect. The sulphoaluminate cement content largely influenced the ultimate tensile strain but little affected the tensile strength. The mechanical properties were optimized in HDCC containing 10% and 15% sulphoaluminate cement. The reduced tensile ductility in sulphoaluminate cement containing HDCC is attributed to the large amount of ettringite formed on the surfaces of the reinforcing PVA (polyvinyl alcohol) fibers.
Study on Energy Consumption Evaluation for Production of High-Titanium Slag
Authors: Gu Jing , Xia De Hong 
Published: November 2019

Abstract
High-titanium slag is not only the substitute for the gradually depleted natural rutile resources but also the important raw material for the clean production of titanium industry. In this paper, a modeling of energy consumption evaluation for production of high-titanium slag using the ilmenite as raw material was proposed, then the energy consumption of high-titanium slag production by direct reduction-melting and separation process (two-stage process) was measured on production site. The energy consumption of high-titanium slag was converted into standard coal energy or electric energy by the energy value method and the energy equivalent method, respectively, on the base of data collected from the plant. The electric energy consumption of high-titanium slag produced by the two-stage process was 1661.6 kWh per ton slag with the energy value method. Due to the energy value conversion method more reflects the value of electricity, which is suitable for applying to the energy consumption evaluation of high-titanium slag production.
Preparation and Characterization of Amino-Functionalized Geopolymer Microspheres
Authors: Chen M L , Ge Y Y , Xue G H , Xu M X , Cui X M 
Published: November 2019

Abstract
Geopolymer microspheres have the advantages of environmentally friendly, cost-effective, easily to synthesize and regenerate, which can be applied for adsorption of heavy metal ions from aqueous solution. In this study, the amino-functionalized metakaolin-based geopolymer microspheres (NH2-MGS) were synthesized by coupling agent method using N-βaminoethyl-γ-aminopropyltrimethoxysilane (AEAPTS). The influences of AEAPTS dosage and temperature on modification efficiency were investigated in detail, and the properties of NH2-MGS were characterized by SEM, EDS, BET, XRD and FTIR analysis. It is shown that amino groups were grafted onto the surface of geopolymer microspheres successfully, and the amount of amino groups grafted increased as the AEAPTS dosage further increasing to 15 wt% and the temperature to 70 °C. The BET specific surface area of NH2-MGS increased significantly from 23.78 to 63.78 m2/g with a corresponding increase of micropores and porosity, which have great potential as adsorbent for removal of heavy metal ions.
Photocatalysts Fabricated by Depositing Ag on Co-g-C3N4 and Its Enhanced Visible-Light Photocatalytic Performance
Authors: Zhou Zhiwei , Qiu Lingfang , Wang Jiahui , Pang Jiawen , Yang Fang , Yang Yuyu , Duo Shuwang 
Published: November 2019

Abstract
A novel photocatalyst, Ag/Co-g-C3N4, was synthesized by a simple photo-deposition method successfully to increase visible-light absorption efficiency and the separation rate of the photogenerated electron hole pairs. A series of characterization analysis were conducted including XRD, SEM, EDS, FT-IR, DRS and PL. The result of DRS shows that there was much visible-light absorption in Co-g-C3N4 compared with pristine g-C3N4. Cog-C3N4 and Co-g-C3N4 loaded with Ag showed a much lower photo-reduced carriers recombination rate according the data of PL. And the different contents of Ag were investigated in detail. The experiment of RhB visible-light degradation indicated the sequence of photocatalytic performances was: Ag/Co-g-C3N4> Co-g-C3N4> pure g-C3N4. The Ag/Co-gC3N4 in this work would be quite useful for removal of organic pollutants.
Construction of ZnO Hollow Spheres Coupled with g-C3N4 as Enhanced Photocatalysts under Simulated Solar Light
Authors: Zhang Xiaoxian , Si Ying , Li Ping , Duo Shuwang 
Published: November 2019

Abstract
Rapid photon-induced e−-h+ pairs recombination rate is a fatal factor restricting the photocatalytic performance of graphitic carbon nitride (g-C3N4). In this work, ZnO hollow spheres (ZnO HS) coupled with g-C3N4 photocatalysts were prepared by a simple mechanical agitation of the mixture of g-C3N4 and ZnO HS in ethanol solution. The as-prepared samples were systematically measured via were characterized by XRD, SEM, DRS, FT-IR and PL. As analysis from the PL test results, the g-C3N4/ZnO HS has much lower photo-generated e−-h+ pairs recombination rate than that of pure g-C3N4. Under the illumination of simulated solar light, the effect of ZnO HS concentration on the photocatalytic properties of as-prepared gC3N4/ZnO HS photocatalysts with different ZnO amount was discussed by the degradation of methyl orange (MO) in detail. The optimum photodegradation performance of g-C3N4/ZnO HS with 5% ZnO HS is almost 47.43% higher than that of pristine g-C3N4. Our research results present a simple and convenient synthetic protocol for processing g-C3N4-based photocatalysts for the degradation of environmental pollutants.
Enhanced Visible-Light-Induced Photocatalytic Performance of g-C3N4/ZnS/CuS Ternary Composite for Environmental Remediation
Authors: Si Ying , Zhang Xiaoxian , Li Ping , Duo Shuwang 
Published: November 2019

Abstract
The inherent drawback of high photo-induced electron-hole pair recombination rate restricts the photocatalytic performances of graphitic carbon nitride (g-C3N4).Here, in this work, g-C3N4/ZnS/CuS ternary nanocomposites with different CuS concentration were successfully fabricated by a hydrothermal process and subsequent followed by a cation exchange reaction. The as-synthesized samples were characterized by the techniques of XRD, SEM, DRS, FT-IR and PL. Characterization results show a much more efficient electron-hole pair separation rate of g-C3N4/ZnS/CuS, the g-C3N4/ZnS/CuS (8%) sample shows the best photocatalytic performance for degradation of Rhodamine B (RhB), which is about 1.6 times higher than that of g-C3N4/ZnS and 6.2 times higher than that of pure g-C3N4, respectively. The high photodegraded activity is attributed to the important role of ZnS and CuS acted as electron co-catalysts, which retard the fast recombination of photo-induced holes and electrons, resulting in higher photodegraded activity than pure g-C3N4.Our research work indicates that the heterostructured formation ofg-C3N4, ZnS and CuS is helpful for the fabrication of g-C3N4-based photocatalysts with enhanced visible light photoactivity.
High-Throughput Preparation and Properties Investigation of BNT Based Lead-Free Piezoelectric Ceramics
Authors: Song Guanhua , Liu Feng , Zhang Faqiang , Liu Zhifu , Li Yongxiang 
Published: November 2019

AbstractA high-throughput (HT) bulk ceramic preparation process was applied to synthesize multi-compositional lead-free piezoelectric ceramics. The lead-free piezoelectric ceramic sample library with a chemical composition of 87Bi0.5Na0.5TiO3-6BaTiO3-7K0.5Na0.5NbO3(87BNT-6BT-7KNN) were prepared to confirm the validity of the HT preparation process. The XRD pattern and surface SEM images showed great consistency of the phase and morphology of the 16 samples in the library. The mean value of dielectric constant and piezoelectric coefficient wereεr= 1848 andd33= 14pC/N. Ferroelectric and strain properties also demonstrated a high consistency ofPs,Pr,Ecandd33*with the mean values of 25.9 μC/cm2, 3.6 μC/cm2, 0.64 kV/mm and 290 pm/V, respectively. The corresponding Coefficient of Variance (CV) values of all these parameters are quite low, which indicate that the HT method reported in this work is feasible in the discovering of new lead-free piezoelectric materials.
Study on the Fluidity Experiments of Engine Oil-Based Magnetic Fluid with Fe3O4/Ag Nanoparticles
Authors: Cao Qianhui , Zhang Zhili , Di Nannan , Zang Guobao , Li Decai 
Published: November 2019

Abstract
In this research, a new engine oil-based Fe3O4/Ag magnetic fluid is prepared applying the method of modified chemical co-precipitation. This preparation method is green without toxic gases being released. The nanoparticles are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and vibration sample magnetometer (VSM). These characterizations demonstrate that the Fe3O4/Ag nanoparticles modified by oleic acid are successfully synthesized and uniformly dispersed in the engine oil. The hysteresis loop of this new magnetic fluid shows that it has no remnant magnetism and maintains superparamagnetic properties. Shear stress and viscosity of both Fe3O4magnetic fluid and Fe3O4/Ag magnetic fluid are measured by the rotational rheometer. The shear stress increases with the increasing shear rate while the viscosity decreases with the increasing shear rate. What’s more, the viscosity of Fe3O4/Ag magnetic fluid significantly increases compared with the traditional magnetic fluid.
A Facile Synthesis of A Novel Cu2Se@CMK-3 Nanocomposite for Rechargeable Sodium Batteries
Authors: Li Ying , Si Yuan , Li Li , Zhang Na , Cen Weihui , Wang Hongqiang , Dai Yejing 
Published: November 2019

Abstract
The rechargeable sodium-ion battery has become a research hotspot due to low cost and a large abundance of sodium resources. In this work, a novel nano-architecture of Cu2Se nanoparticles imbedded in ordered mesoporous carbon (Cu2Se@ CMK-3) was synthesized. Benefiting from the high conductivity and special nano-architecture of CMK-3 matrix, the as-synthesized Cu2Se@ CMK-3 composite delivers a high specific discharge capacity (231 mA h g−1) and superior cycling stability (a capacity decay of 0.33% per cycle during 100 cycles at 0.1 C) when used as cathode in sodium-ion batteries.
Preparation and Electrochemical Properties of Ba1-xLaxF2+x Fluoride Electrolyte
Authors: Cheng Xing , Wang Shu , Lin Xuping 
Published: November 2019

Abstract
A series of Ba1-x
La
x
F2+x
composition powders with different values of x were prepared by water and ethanol mixed solvent method. The effects of different values of x on the phase composition, crystal structure and electrochemical properties of Ba1-x
La
x
F2+x
electrolyte were studied. The electrical conductivity of Ba1-x
La
x
F2+x
at different temperatures was investigated by electrochemical impedance spectroscopy. The results of transmission electron microscopy showed that the prepared Ba1-x
La
x
F2+x
powders ranged in size from 10 to 25nm and dominated by crystalline phases. XRD results show that the Ba1-x
La
x
F2+x
electrolyte gradually changes from fluorite structure to tysonite structure with the increase of x value. Electrochemical impedance spectroscopy was used to study the electrical properties at 25, 50, 75, and 100°C. It was found that the ionic conductivity of the Ba1-x
La
x
F2+x
electrolyte at the same temperature increased with the increase of temperature. When x is small, the main carrier of Ba1-x
La
x
F2+x
electrolyte is F−. When x is too large, it mainly depends on F−vacancy conduction, while the conductivity of the former is lower at lower test temperature. The contribution is much larger than the latter, which is also the main reason for the decrease of conductivity of Ba1-x
La
x
F2+x
electrolyte when x is too large. At the same temperature, Ba0.6La0.4F2.4 is always the maximum conductivity.
The Study of Atmospheric Pressure CVD Growth Process of MoxW1-xTe2 Nanobelts for Tuneable Chemical Composition
Authors: Liu Shijian , Qiu Haipeng , Liu Shanhua , Zou Jin , Chen Zhigang 
Published: November 2019

Abstract
Transition metal dichalcogenides nanomaterials with topological semimetallic phase (MoTe2, WTe2 and MoxW1-xTe2) are expected to realize no-consumption electronic transportation due to its Dirac point. Especially, the various structure existence in MoxW1-xTe2, like hexagonal (2H), monoclinic (1T’) and othorombic (Td), provides opportunities for phase engineering, which is beneficial for future novel electronic and spintronic devices. Plenty works have focused on the synthesis of MoTe2, WTe2 and MoxW1-xTe2 nanomaterials. Unfortunately, the understanding of the growth process of MoxW1-xTe2 nanomaterials is still absent and the exact control of the atomic ratio between Mo and W in MoxW1-xTe2 nanomaterials is still a huge task up to now. Here, we study the growth process of MoxW1-xTe2 nanomaterials by the growing of binary MoTe2 and WTe2 nanomaterials. Through detailed structural and compositional characterization, same growth mode, crystallography, and morphology have been observed among MoTe2, WTe2 and MoxW1-xTe2 nanomaterials. Through analysis, we suggest that the heating temperature of Mo and W precursors during the CVD process is the key parameters to achieve the tuneable chemical composition of MoxW1-xTe2 nanomaterials. This study dissected the growth process of MoxW1-xTe2 nanomaterials and provided a possible method to control the chemical composition of MoxW1-xTe2 nanomaterials by APCVD, which is beneficial to realize the phase engineering in Mo-W-Te system and also for future topological application.