bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation and Properties of Porous SiC/SiC Composites
Authors: Xie W J , Zhao Y L , Wang Q M , Guan H , Qiu H P 
Published: November 2019

Abstract
The purpose of this study was to investigate the preparation and properties of porous SiC fiber reinforced SiC matrix (SiC/SiC) composites. SiC/SiC composites were prepared by polymer impregnation pyrolysis (PIP) progress with polycarbosilane (PCS) as impregnate and SiC fiber as reinforcement. The pores of the composites were pre-introduced by regulating the distribution of yarns during the braiding of the fiber preform. The apparent porosity, pore structure and the tensile strength were studied and compared with the laser drilling composites. The results show that the properties of the composites pre-perforated by fiber preforms are superior to the composites drilled by laser.
Oxidation Behavior of TiB2/Ta-W Composites
Authors: Li Jiaxin , Chen Yuhong , Zhao Chenghui , Jiang Liang , Wang Hongye 
Published: November 2019

Abstract
TiB2/Ta-W composites and Ta-10W alloy are prepared by hot-press sintering. The composites and alloy are oxidized in air at 700°C, 800°C and 900°C, respectively. The phase components of the as-prepared composites, alloy and oxidized layer were analyzed through XRD and SEM/EDS. The results showed that TiB2 reacted with both tantalum and tantalum oxide on the surface of Ta particles, which leads to the formation of intermetallic compounds Ta2B and Ta3B2. An oxidation layer of Ta2O5 solid solution was identified. Oxidation kinetics curves of all samples in air obeyed liner law, because a stable protective oxide scale could not be formed on the surface of samples.
PAS Fabrication and Densification Mechanism of B-Al-Ti-C System Ceramics
Authors: Luo Guoqiang , Fan Peng , Kang Kejia , Sun Yi , Zhang Jian , Shen Qiang , Zhang Lianmeng 
Published: November 2019

Abstract
In this paper, B-Al-Ti-C system ceramics were fabricated by plasma activated sintering(PAS) technique. The final sintered products consisted mainly of AlB12C2 and TiB2. The specimens could be densified at the temperature of 1460 °C∼1600 °C, which is near 400 °C lower than the dense pure AlB12C2 and TiB2 ceramics. The sintered samples are nearly fully dense, and there are substantially no pores observed by observing the SEM photograph. The mechanism of low temperature densification and the phenomenon of varied specimens during sintering were explained in details in this study.
Effect of Pyrolytic Carbon Coating on Properties of Cf/C-SiC-ZrC Ceramic Matrix Composites
Authors: Su C.L. , Zhou Y.Y. , Jiang K. , Yang F.H. , Xu H.Z. , Zhou C.L. , Liu F.T. 
Published: November 2019

Abstract
In this paper, Cf-SiC-ZrC, Cf/C-SiC-ZrC composites which the pyrolytic carbon (PyC) coating with the thickness of 0.1 μm, 0.3 μm and 0.5 μm were prepared by chemical vapor deposition (CVD) process combined with precursor infiltration and pyrolysis (PIP) process. Then, SEM, XRD and other methods were used to test the microstructure, flexural strength, fracture toughness and static oxidation of the composites. The results show that after the CVD process, PyC with higher degree of graphitization is deposited on the carbon fiber surface, which can avoid damage to the carbon fiber caused by the PIP process for preparing the ceramic matrix composite. The mechanical properties and oxidation resistance of Cf/C-SiCZrC ceramic matrix composites are higher than Cf-SiC-ZrC composites, and the flexural strength reached 283 MPa, the fracture toughness reached 4.40 MPa•m1/2. After oxidation for 30 min at 1400°C, we found that the composite with PyC coating of 0.3 μm had good oxidation resistance.
Effect of Hot Pressure Parameters on W-SiC/Cu Composites Densification
Authors: Zhang Chengcheng , Shen Qiang , Zhang Jian , Luo Guoqiang , Sun Yi , Li Yuan , Zhang Lianmeng 
Published: November 2019

Abstract
In the paper, 30W-30SiC/40wt.%Cu composites were fabricated by tape casting and hot-pressing sintering. Microstructures of the W-SiC/Cu green tape and the green tape after organic additives removal were studied. The results showed that W, Cu and SiC particles exhibited a uniform distribution. The effects of sintering temperature, sintering pressure and holding time on the microstructures, porosity, and density of the W-SiC/Cu composites were investigated. The results showed the porosity of the W-SiC/Cu composites decreased and the density increased with the increasing of the sintering temperature, sintering pressure and holding time. The porosity and density of the W-SiC/Cu composite prepared at the condition of 900 °C- 200 MPa- 2 h achieved 0.52 % and 9.84 g/cm3.
Fabrication of Transparent Yb:Sc2O3 Ceramics by Hot Isostatic Pressing Without Sintering Additive
Authors: Ma Mingzhen , Dong Linlin , Jing Wei , Xu Tao , Kang Bin , Hou Feng 
Published: November 2019

Abstract
Highly transparent Yb:Sc2O3 ceramics were successfully fabricated using commercially powders without any sintering additive by a hot-isostatic-press (HIP) method. The ceramics were sintered at 1700°C in vacuum followed by HIP at 1680°C to obtain a relatively high transmittance. The effects of Yb doping concentrations on the microstructure and transmittance were investigated, respectively. The samples with a doping concentration of 10 at% achieved the highest transmittance, which showed 79.4% at a wavelength of 800 nm. The fluorescence emission spectroscopy suggests that it is promising to achieve laser output at around 1080 nm. These results may afford a enchiridion for comprehending the microstructural development of transparent Yb:Sc2O3 ceramics without sintering additive.
Effects of SiC Micro-Powder Content on Properties of RSiC Porous Ceramics Supports
Authors: Liang Pengpeng , Wu Jiguang , Han Jianshen , Wang Gang , Zhang Qi , Li Luning 
Published: November 2019

Abstract
The sintering mechanism of recrystallized silicon carbide (RSiC) is mainly “the evaporation-condensation process” of silicon carbide. In the process of sintering, no liquid phase is generated and the samples almost do not shrink. After sintering, the pore connectivity of the specimens comes excellent, so the gas permeability of the RSiC porous ceramic supports is very good. The influences of SiC micro-powder content on the properties of the supports were investigated. Specifically, the open porosity, cold modulus of rupture, hot modulus of rupture at 1200°C, pore size distribution, and gas permeability of samples were measured. The microstructure and phase composition of samples were also analyzed by SEM and XRD. Our results show that RSiC porous ceramic supports with not-too-high apparent porosity but excellent permeability and mechanical properties at room and high temperature can be prepared by simply adjusting the amount of SiC micro-powder.
Delaying Effect of NaCl on The Conversion of Hydrates of Calcium Aluminate Cement
Authors: Ping Wang Zhong , Yu Yang Hao , Zhao Ya Ting , Lin Xu Ling , Wang Jiang , Jia Da Li 
Published: November 2019

Abstract
The effect of NaCl on the conversion of hydration products of calcium aluminate cement(CAC) was determined by means of MIP, XRD, DSC-TG and SEM. Results show that the addition of NaCl promotes the formation of CAH10 at early hydration stage. The total porosity and proportion of harmful pore in hardened CAC paste with NaCl are lower and the 7d-strength is 40% higher than that of the control. The later curing at 40°C accelerates the conversion from metastable C2AH8, CAH10 to C3AH6, and the strength decreases with the increasing of curing age. After 90 days, there is no metastable hydrate detected in CAC paste. However, the addition of Niacin CAC paste can prominently delay the conversion of C-A-H. Massive CAH10 still exists in the paste with NaCl, resulting in a slower retraction of late strength.
Effect of Protective Coatings on Frost Resistance of Concrete Structures in Northeast Coastal Areas
Authors: Caiyun WU , Li Weihong , Zhang Cheng , Jinpeng FAN 
Published: November 2019

Abstract
Dalian is located in the northeast coastal area, and the complex environment has caused severe freezing and thawing damage to the marine concrete. The experiment used polyurea, polyurethane, epoxy mortar to protect the concrete surface, and then carried out indoor rapid freeze-thaw test to analyze the effect of coating on the antifreeze performance of concrete. The concrete samples were subjected to mercury intrusion test before and after the freeze-thaw cycle to analyze the pore structure changes of the concrete before and after erosion. The test results show that the concrete covered by protective coating has a lower mass loss rate and a higher dynamic elastic modulus than the unprotected concrete, the order of anti-freezing performance of the protective coating from strong to weak is: epoxy mortar > polyurethane > polyurea. By isolating the concrete from the corrosive environment, the protective coating can delay the ingress of corrosive materials, slow the tendency of harmless pores in the concrete to multiple the harmful holes and harmful pores, improve the frost resistance of the concrete, and prolong the use of the concrete structure life.
Research on Rebound Rate of Nano-Scale Admixture Wet-Mix Shotcrete
Authors: Wei Ning Feng , Bo Cai Yue , Bai Yin , Tong Ding Jian , Zhang Feng 
Published: November 2019

Abstract
High rebound rate and low construction efficiency are outstanding problems for traditional shotcrete. To solve these problems, Nano-scale admixture (NSA) was used to prepare high performance wet-mix shotcrete. Tests of sidewall rebound rate and overall rebound rate were carried out to study the effect of NSA. A total of eight mixtures were measured to assess the effect of impact factors such as active admixture variety (silica fume and NSA), NSA content (7.5%, 10% and 12.5%) and NSA fineness (128nm, 137nm and 147nm) on rebound rate. The results indicated that the sidewall rebound rate and overall rebound rate of shotcrete were reduced by 17% and 25% respectively when NSA replaced silica fume at the same content, which was about 10% with respect to the total amount of cementing materials. Rebound rate decreased as NSA content increased from 7.5% to 12.5%. Rebound rate also could be reduced when particle size of NSA deceased from 147nm to 128nm. The results confirmed the role of NSA in reducing rebound rate of shotcrete. NSA could promote the adhesion between shotcrete and receiving surface, improve the cohesion in mixtures, which could keep such as coarse aggregate, synthetic fiber from being rebounded out of cementing paste. Therefore, the rebound rate was reduced.
Effect of Heat Treatment on Structure, Morphology and Surface Properties of Halloysite
Authors: Wu Hongdan , Zhang Jinhua , Zhou Zhihui 
Published: November 2019

Abstract
Halloysite was one of the nanoscale tubular minerals in nature. The objective of the present study was to investigate the effect of heat treatment on structure, morphology and surface properties of tubular halloysite, which were significant in the applications of halloysite as functional materials but had received scant attention in comparison with kaolinite. X-ray diffraction (XRD), thermo gravimetric analysis (TG-DSC), field scanning eletron microscope (FSEM), transmission electron microscope (TEM) and surface area measurement (BET) were adopted to characterize raw and heated minerals. The interior diameter of halloysite tube was about 50 nm, and the length of tube was in the range of 0.5-1.0 μm. A series of substantial changes in crystalline structure and phase state occured in halloysite after heated treatment. The FSEM and TEM images of halloysite showed that the unheated halloysite particles possessed typical cylindrical shapes and contained transparent central areas that run long-itudinally along the cylinder, indicating that the cylinders were hollow and open ended. The morphology of the halloysite had no obvious change before and after heat treatment. Specific surface areas (SBET) of the raw and heated mineral below 800 °C were similar (in the range of 35-36 m2/g), suggesting that it still maintained tubular structure.
Study on Flakes of a Steel Roller
Authors: Peng Cheng-Hong , Zhu Wei-Heng , Liu Zheng-Yi 
Published: November 2019

Abstract
The study of flakes is rare, but once it occurs, the material will suddenly burst, and the consequences are very serious. In this paper, the surface burst reason of a steel rolling mill backup roll was analyzed. The backup roll material meets a criterion of 86CrMoV7 ingredient, there are silver gray round and oval defects on macro fracture surface, visually there are more silver gray white fisheyes on the debris of the failure roller. Microscopic fracture morphology has obvious brittle fracture characteristics. The hydrogen of local surface area measured failure roller reaches 9×10−4 %, more than three times the allowable amount that flake no appear. Failure roll hairline cracks, or snow flakes assessed according to the standard are grade 2-3, which is a more serious flake level. The analysis results show that the flake is the main cause of the backup roll premature failure.
Study on the IGZO Ceramics Sintered at Different Temperatures
Authors: Qi Chao , Zhong Jingming , Chen Jie , Luo Wen , Sun Benshuang , Liu Bingning , Shu Yongchun , He Jilin 
Published: November 2019

Abstract
In this study, the IGZO target was synthesized through a pressureless oxygen atmosphere sintering technique, and the effects of sintering temperature on IGZO ceramic target were studied. The In2O3, Ga2O3 and ZnO powders in the mole ratio of 1:1:2 were selected as raw materials. The powders were mixed by ball milling, and then the granulation and pressing process were used in order to obtain the green compacts. Then the green compacts were sintered at different temperature under oxygen atmosphere. The microstructure characterizations and compositions of the IGZO ceramic targets were analyzed. The results indicated that the lower sintering temperature was beneficial for IGZO ceramics to form the regular polygonal grains. With the temperature increased, the densification of IGZO ceramics was highly activated, and the low porosity was obtained. The XRD results demonstrated that the single phase of InGaZnO4 had been generated at 1100°C and no phase transformation occurred between 1300°C and 1500 °C. However, the SEM results showed that the grain growth of IGZO target was very obvious at 1500°C. The IGZO ceramic had a highest relative density of 99.4% and optimal resistivity of 18 mΩ·cm at the sintering temperature of 1400°C.
Fabrication and Application of Superhydrophobic MultiStage Structure Separation Membranes
Authors: Li Huaxin , Chen Junyong , Yue Xian , Yu Xianbo , Xiang Junhui 
Published: November 2019

Abstract
In this paper, the copper mesh was used as the base material, and the uniform nanowire structure was obtained by surface modification of the base material. The hydrophobic silica nanoparticles were grown in situ on the nanowires to obtain the prepared material with SiO2 nanoparticles/Cu(OH)2 nanowires (SiO2NPs/CuNWs) multi-stage structure. Fourier transform infrared spectroscopy (FTIR) showed that a large amount of methyl (-CH3) was present on the surface of the prepared material after modification of methyltrimethoxysilane (MTMS). Because of the existence of -CH3, the surface energy of the prepared material was reduced, so the hydrophilic substrate surface was changed into hydrophobic surface. Scanning electron microscopy (SEM) showed that the surface of the prepared material was uniformly distributed with SiO2NPs/CuNWs multi-stage structure, which improved the surface roughness of the base material, thus, the hydrophobic property was greatly improved. The contact angle (CA) of water droplet at the interface reaches 154°, indicating that the prepared material had excellent hydrophobic properties. Based on the porosity and surface hydrophobicity of the prepared material, it can be used to separate various oil-water mixtures efficiently.
The Correlation Between Structure and Photocatalytic Activity of ZnO Particles Prepared by Mild Wet Chemical Method
Authors: Ai Jianping , Liao Weixiu , Zhou Zehua , Cheng Lihong , Chen Zhiqin , Hu Changyuan , Zhang Yue , Luo Shanshan , Li Wenkui 
Published: November 2019

Abstract
Flower-like and roughly spherical ZnO nanocrystalline have been successfully synthesized through mild wet chemical method. The photocatalytic activities of the prepared photocatalysts were evaluated by degradation of rhodamine B (RhB) and phenol under UV light irradiation. Remarkably, the roughly spherical ZnO powder via homogeneous precipitation method exhibited superior photocatalytic performance and better photo-stability than that of flower-like ZnO substrate by hydrothermal synthesis way. The enhanced photocatalytic properties could be attributed to more active catalytic sites and superior charges separation efficiency.
Synthesis and Photocatalytic Performance of g-C3N4 Modified with AgSAPO-5 for Photodegrading Rhodamine B
Authors: Qiu Lingfang , Zhou Zhiwei , Yang Yuyu , Yang Fang , Duo Shuwang 
Published: November 2019

Abstract
In this study, AgNO3 solution was used to modify natural SAPO-5 zeolite and hybrid AgSAPO-5 zeolite was formed. The effect of the concentration of AgNO3 solution on AgSAPO-5 was discussed. The crystal phase and elements in frameworks of AgSAPO-5 samples were characterized by XRD, FT-IR and EDS. AgSAPO-5 with highest visible-light adsorption verified by DRS was used to prepare AgSAPO-5/g-C3N4 composites. The mass ratio of AgSAPO-5 and g-C3N4 was changed. AgSAPO-5/g-C3N4 composites were also characterized by XRD, DRS and PL. The band structure of g-C3N4 was changed successfully so that the light adsorption changed. The much lower intensities of AgSAPO-5/g-C3N4 composites declare that the combination rate of g-C3N4 was retarded significantly. The composites were tested for photocatalytic activity in rhodamine B (10 mg/L) solution under visible light illumination. The results showed that AgSAPO-5/g-C3N4 composite with a mass ratio of 15% exhibited the highest photocatalytic performance with an efficiency of 90.56% within 50 min.
Fabrication and Microwave Absorption Performances of FeNi-CoFe2O4-PANI Composites
Authors: Li Ze , Wang Jianjiang , Zhao Fang 
Published: November 2019

Abstract
Flake FeNi alloys were fabricated by micromachining, CoFe2O4 and PANI were loaded on the surface of the flake FeNi alloys by coprecipitation and in-situ polymerization. Finally the FeNi/CoFe2O4/PANI composites with electromagnetic absorption properties were obtained. The morphology, composition and microwave absorbing properties of the composites were studied by SEM, XRD, FTIR and VNA. The results showed that CoFe2O4/PANI is deposited on the surface of the matrix, and a small amount was dissociated. The permittivity and the low-frequency absorbing property of the composites was improved. At the frequency of 2.2GHz, the lowest reflection reached -12.2dB. By analyzed the electromagnetic properties and using the theory of 1/4 wavelength interference cancellation, the reasons for the improvement of low frequency absorbing properties of composites were explained.
Extraction of Potassium from Biotite by Sr2+/K+ Exchange Method and Electrochemical Properties of Hydrated Sr-Mica
Authors: Yao Donghui , Huang Zhiliang , Pan Bingbing , Zhao Zhouqiao 
Published: November 2019

Abstract
Soluble potassium has been successfully extracted from biotite by Sr2+/K+ ion exchange. The hydrated Sr-mica after ion exchange has better electrochemical properties. The potassium extraction rate, mica silicate structure and electrochemical properties (charge-discharge and cycling properties) before and after ion exchange were characterized by X-ray fluorescence spectroscopy, powder X-ray diffraction, Fourier Transform Infrared spectrometer and constant current charge-discharge cycle technology. The results show that after 10 hours of strontium ion exchange, the layered silicate structure is not destroyed. The maximum potassium extraction rate is 98%. The biotite gradually transforms into vermiculite strontium mica to form strontium mica, and the basal (001) spacing expands from 1.001 nm to 1.517 nm. The electrochemical properties of hydrated Sr-mica obtained after exchange have been improved.
Facile Synthesis of Magnetic Reduced Graphene Oxide-ZnFe2O4 Composites with Enhanced Visible-Light Photocatalytic Activity
Authors: Ai Jianping , Xu Weihang , Zhang Ruibo , Su Kaiyu , Hu Liling , Cheng Lihong , Ouyang Xiaohua , Li Wenkui 
Published: November 2019

Abstract
Magnetic ZnFe2O4-the reduced graphene (rGO) nanocomposites (ZnFe2O4-rGO NCs) have been successfully synthesized by a facile solvothermal method. The photocatalytic activities of the prepared photocatalysts were evaluated by degradation of methylene blue (MB) dyes under visible-light irradiation. In comparison with ZnFe2O4 nanoparticles(NPs) catalyst, the ZnFe2O4-rGO NCs can generate more hydroxyl radicals (•OH) via photoelectron chemical decomposition of H2O2. Moreover, the as-prepared ZnFe2O4-rGO NCs can magnetically separable in a suspension system. Therefore, they can be conveniently applied to dispose toxic organic pollutants during water treatment.
Research on the Robot’s Automatic Road Detection Technology with SRPS
Authors: Jianzhong Zhang , Qiang Xu 
Published: November 2019

Abstract
Road detection technology has been widely used in many fields, such as vehicle’s assisted driving, robot autonomous navigation, military defense, public security and so on. In this paper, the road detection method based on sensitive region pixel sequence (SRPS) solution is studied. Firstly, the recent advances of the road detection method based on machine vision are summarized. Secondly, analyses the principle of road detection technology based on sensitive region pixel sequence (SRPS) solution to improve road detection efficiency and accuracy of the vision method. Finally, experimental results show that the sensitive region pixel sequence (SRPS) solution has an important significance to reduce the calculation cost of the robot’s road detection system.