bluuebunny/crossref_metadata_2025_split huggingface dataset:
Environmental Performance Test and Analysis of SiC/SiC Composites
Authors: Chen Mingwei , Qiu Haipeng , Xie Weijie , Zhang Bingyu 
Published: November 2019

Abstract
SiC/SiC ceramic matrix composites were prepared by polymer impregnation pyrolysis (PIP) process with domestic first-generation SiC fibers as reinforced phase and SiC ceramic as matrix phase. The structure and morphology of SiC ceramic matrix and SiC/SiC composites were investigated by means of XRD and SEM method. Furthermore, the mechanical properties of SiC/SiC composites after high temperature gas testing were investigated by flexural strength using three point bending testing. Results showed SiC/SiC composites have excellent mechanical properties at room temperature with bending strength of 330 MPa. However, obvious cracks and serious oxidation appeared after up to 150 hours of high temperature gas testing, and the mechanical properties dropped dramatically with the flexural strength retention rate less than 50%. The decrease of the mechanical properties and the occurrence of cracks of SiC/SiC composites were mainly attributed to the structure evolution and the oxidation intensification which might lead to instability of material properties and component structure.
The microstructure and mechanical properties of silicon carbide fibers with boron nitride interphase
Authors: Lv Xiaoxu , Qi Zhe , Jiang Zhuoyu , Zhou Yiran , Zhao Wenqing , Jiao Jian 
Published: November 2019

Abstract
The 2nd generation SiC tows is a type of essentially polycrystalline fibers (SiC1.46O0.03). Smooth and uniform boron nitride interphase was deposited on SiC fibers by low pressure chemical vapor infiltration (CVI). The scanning electron microscopy(SEM) was used to characterize the microstructure of the BN interphase and fibers while X-ray diffraction(XRD) and TEM were used to characterize the phase constitute of the fibers. The XRD and TEM results showed that the BN interphase prepared by CVI is turbostratic. The effects of thickness on the mechanical properties of SiC fibers were investigated by using two-parameter Weibull distribution. The fibers with thin BN interphase showed higher strength than the as-received fibers, for healing the surface flaws. However, the soft nature of increasing BN thickness had a more dominant effect and resulted in the decrease of fiber strength.
Effect of Carrier Gas on the Conversion Process of BN Organic Polymer Precursor to BN Ceramic
Authors: Chen Mingwei , Qiu Haipeng , Xie Weijie , Zhang Bingyu , Liu Shanhua , Luo Wendong , Ma Xin 
Published: November 2019

Abstract
Boron nitride organic polymer precursors were pyrolyzed under different carrier gases such as NH3, Ar and N2. The conversion process of BN organic polymer precursor to BN ceramic was characterized by means of TG, FTIR, and elemental analysis. Results showed that NH3 could promote conversion process which was beneficial to the occurrence of hydrolysis, crosslinking and decomposition reaction. Therefore, lower carbon residue existed and more regular inorganic structure were obtained in boron nitride precursor pyrolytic products which would be helpful to gain BN fiber with excellent wave transparent properties.
Preparation and Properties of Cf/SiC-ZrC Ultrahigh Temperature Ceramic Matrix Composites
Authors: Wang Yanyan , Zhai Lingyu , Li Xiaobo , Xing Zhengpeng , Gong Xiaolin , Chen Pengyu , Qingsong-Xie  
Published: November 2019

Abstract
Ultra-high temperature materials have many excellent properties, such as high melting point, high specific strength, high thermal conductivity, high conductivity, corrosion resistance and good chemical stability, which make them become high temperature structural materials for aircraft in extreme environments.Cf/SiC-ZrC ultra-high temperature ceramic matrix composites were fabricated by the combined process of chemical vapor deposition and precursor infiltration pyrolysis (CVI-PIP) in this study. The phase composition and microstructure features of the composites were characterized using X-ray diffraction, scanning electron microscopy. A PyC layer was observed as the interfacial layer between carbon fiber and the ultrahigh temperature ceramic matrix. It can protect the carbon fiber from damage during the cyclic PIP process. Nano crystalline ZrC particles were observed in the composites. The ablation mechanisms of the composites were tested in arc-jet wind tunnel and it exhibited good ablation-resistant properties. The ablation mechanism of composite materials in wind tunnel environment is discussed.
Oxidation Behavior of ZrB2-SiC Modified Zr3[Al(Si)]4C6 Composites Exposed to Air
Authors: Wang Xuhong , Liu Hui , Zhang Jianhao , Ji Wangjin , Shi Si , Hu Jian , Liu Yurui , Yu Lei 
Published: November 2019

Abstract
The oxidation behavior of Zr3[Al(Si)]4C6-matrix composites reinforced by adjusted content of ZrB2-SiC with fixed molar ratio of 2:1 was investigated. The composites were exposed to air at medium temperatures, and the oxidation kinetics of the composites generally follow a parabolic law. With the ZrB2-SiC content increasing from 0 to 40vol.%, the oxidation weight gain per unit surface area (Δw/s) and oxidation rate constant (k
p) of the specimens increase and then decrease at the same oxidation conditions. The high content of ZrB2-SiC is benefit for improving the oxidation resistance of the composites. And, the lowest k
p of the composite incorporated with 40vol.%ZrB2-SiC is about 2.43×10−6kg2·m−4·s−1 when oxidized at 1100°C, which is stillhigherthan that of monolithic Zr3[Al(Si)]4C6. In addition, the phase composition and microstructure of oxidation products and the oxidation mechanism of materials were analyzed and discussed.
Fabrication of Yb:Lu2O3 Transparent Ceramics by Hot Isostatic Pressing: the Effect of Yb Doping Concentrations
Authors: Dong Linlin , Ma Mingzhen , Jing Wei , Xu Tao , Kang Bin , Guo Ruisong 
Published: November 2019

Abstract
Highly transparent ytterbium doped lutctium oxide (Yb:Lu2O3) transparent ceramics with different Yb doping concentrations (0.5–10 at% Yb) were fabricated from commercial powders by vacuum sintering combined with hot isostatic pressing (HIP) method. The effects of Yb3+ doping concentrations on the microstructure, optical performance and the thermal conductivity of Yb:Lu2O3 transparent ceramics were investigated. The grain size of Yb:Lu2O3 ceramics first decreased with Yb doping concentration increasing and then kept nearly unchanged at high Yb doping concentrations. Under 1750°C HIP sintering for 2h, The in-line transmittance of the 5 at.% Yb:Lu2O3 ceramics (3 mm thick) exceeds 81.52% at 1100 nm. And it had the average grain size about 2μm. As the doping concentrations increase, the overall thermal conductivity decreases slightly. The fluorescence emission spectrum implied high possibility of realizing laser output at 1080 nm by pumping at 980 nm.
Luminescence Properties of Ce3+ Doped Garnet Ca2LaZr2Al3O12 Phosphors
Authors: Yu Ming , Wang Baochen , Liu Yan-gai , Wang Lu , Xia Yufei , Huang Zhaohui , Fang Minghao 
Published: November 2019

Abstract
A series of novel Ca2LaZr2Al3O12: xCe3+garnet phosphors were obtained by conventional high temperature solid-state reaction. Crystal structure, phase purity, micromorphology as well as luminescence properties are studied via X-ray powder diffraction, scanning electron microscope and photoluminescence spectra including excitation and emission. Moreover, the mechanism of concentration quenching, thermal stability, fluorescent lifetime and quantum efficiency were investigated in detail. Under n-UV excitation, Ca2LaZr2Al3O12: Ce3+ exhibits a broadband of blue emission at 440 nm approximately for maximum, corresponding to 5d-4f transition of Ce3+. Emission can keep 41% of initial intensity when temperature is promoted to 373 K according to temperature-dependence emission spectra. The internal quantum efficiency of the optimal specimen is 15% and with Ce3+ increasing, the color of emission transfers to light from dark blue at CIE.
Research on Oxidation Resistance of Silicon Carbide Refractories to High Temperature Steam
Authors: Xiang Y B , Guo A , Wang WW , Wan L G , Cao H Y , Huang Z G , Wang J P , Wu J G , Si Y C 
Published: November 2019

Abstract
Refractory linings of waste incineration plants based on oxidation resistant SiC materials enable a long service life at suitable firing and operation conditions. Steam oxidation resistance of Si3N4-SiC, SiO2-SiC, SiAlON-SiC material at 1000°C was tested according to ASTM-C863 after 50c, 100h, 200h, 250h and300h respectively. The phase composition and microstructure before and after oxidation were analyzed by means of XRD and SEM. Results indicate that there is continuous increase of volume expansion and weight change on materials with the oxidation to the oxidation time. After 50h of oxidation, a small amount of cristobalite can be observed in these materials, which comes directly from the oxidation of SiC, Si2N2O and SiAlON or from the crystallization of glass phase. Oxidation weight gain occurs in the first 50 h, but volume expansion takes place after 50h . Compared with the three materials, SiO2-SiC material has a smaller weight change and volume expansion. Comparing the SEM these three materials, it is obvious that SiO2-SiC material has a better density after 300h. Based on the above results, conclusions can be reached that: the sample of SiO2-SiC has better oxidation resistance and is more suitable as lining material of waste incinerator.
Effect of AlF3 Content on the Properties of In-situ Generated Mullite Whisker Reinforced High Aluminum Castables
Authors: Li Jijia , Luo Xudong , Xie Zhipeng , Yang Mengmeng 
Published: November 2019

Abstract
The mullite whiskers have excellent high temperature resistance and high heat characteristics, the melting point is above 2000°C, and the maximum use temperature is 1500°C to 1700°C. In this paper, mullite whiskers were prepared by in-situ growth method. High aluminum castables were prepared by injecting mullite whiskers in situ at high temperature by adding Al(NO3)3·9H2O and NH4F to high alumina castables. It is 0, 0.5 wt%, 1 wt%, 2 wt%, 4 wt%. The materials were mixed, stirred, cast, and demolded and then fired at 1400°C. By testing the bulk density, apparent porosity and residual flexural strength of the samples, the properties, microstructure and microstructure of the fired samples were analyzed and characterized by means of XRD and SEM. The study focused on AlF3 to mullite whiskers. The effect of microstructure and flexural strength. The results show that the introduction of AlF3 promotes the formation of mullite whiskers. With the increase of AlF3 content, the aspect ratio of whiskers increases first and then decreases, and when the AlF3 content is 1wt%, the aspect ratio of whiskers The maximum is 6.67. Excessive AlF3 causes the mullite whiskers to become thick and rod-shaped. The in-situ mullite whiskers form an interlocking structure, which enhances the flexural strength of mullite high-aluminum castables when AlF3 content When the weight is 1wt%, the flexural strength of the model reaches the maximum value of 35.92MPa, and the residual flexural strength of the sample after 5, 10, and 15 thermal shocks reaches the maximum, which are respectively 2.07 MPa, 1.95 MPa, 1.19. MPa.
Preparation of Sustained Release Mixture Aerogel Antibacterial Agent
Authors: Guo Xiaowei , Chen Nanchun , Meng Xiangjian , Wang Xiuli , Li Yuyan , Xie Qinglin 
Published: November 2019

Abstract
In this study, Hybrid aerogels of chitosan (CS), carboxymethyl cellulose (CMC) and Zeolite P molecular sieve (zeolite P) are successfully prepared by using Calcium chloride as the Chelator. pH-controlled drug delivery with CS/CMC/Ca2+/Zeolite P as the carrier is investigated using antibacterial agents potassium diformate (KDF), as the model drug. CS and CMC have pH sensitivity. The Zeolite Phas a large specific surface area which contributes to the enhancement of drug-loading amount. Thus, the synthesized microparticles were characterized by FTIR and XRD, and study the surface morphology of particles by SEM. The swelling and in vitro antibacterial activity of the prepared composites were studied. The particle systems developed are promising for adjusting the pH of the intestine and modulate gut microbiota in the intestinal tract with the purpose of improving piglets health.
Pinhole Effect Investigation in Electrowetting Dielectrics by Current Density Measurements
Authors: Wang Weiqiang , Yan SU 
Published: November 2019

Abstract
In this paper, we use current density measurement as an important diagnostic method to study the reliability of electrowetting devices. The current density distribution data is closely related to the early detection of malfunctions or failures in the devices. Here we use segmented cell technology to investigate the current density distributions in the top substrate to determine the initiation of dielectric breakdown. The current density measurements are further used to determine the signature of pinhole formation in the dielectric film. Different behavior is observed for dielectric failure under DC and AC voltages, and a sudden current change associated with vaporization of water is assumed to trigger the failure of the device.
Electrospinning Preparation and Infrared-Emissivity Properties of Zn1-xCoxO Nanofibers
Authors: Wang Xinkun , Zhao Fang , Wang Jianjiang , Ma Weining 
Published: November 2019

Abstract
Wurtzite-type Zn1-xCoxOnanofibers were successfully fabricated by sol-gel method combined with electrospinning technology. The as-prepared fiber samples were characterized by TGA-DSC, XRD, FTIR and SEM techniques. The infrared emissivity of the product were tested using an IR-2 infrared emissivity analyzer. The results show that wurtzite structure is formed at 600°C for 2h. These nanofibers have diameters in the range of 60-100nm. As the doping concentration increases, The infrared emissivity of the sample decreases first and then increases slowly. When x = 0.04, the lowest infrared emissivity is 0.76.This makes Zn1-xCoxO nanofibers have a good prospect in the infrared emissivity nanomaterials.
Enhancement of Microstructure Development and Current-voltage Characteristics of ZnO-Bi2O3Varistor Ceramics Sintered with Sintering aids at the Low-Temperature
Authors: Liu Wenjin , Cheng Lihong , Ai Jianping , Su Kaiyu , Li Wenkui 
Published: November 2019

AbstractZnO-Bi2O3based varistor ceramics doped with SnO2or with SnO2, B2O3and SiO2were prepared by traditional solid–state reaction method respectively. The microstructure and properties of samples sintered at a low temperature range from 910 to 950°C were studied. Results show that: by low-temperature sintering, the sintering aids can improve the sample’s density and homogeneity, and therefore the overall properties of the samples. It was found that the samples sintered at 910°C with SnO2as sintering aid possess the best performance, and the breakdown voltage is 1368 V/mm, nonlinear coefficient is 12.2, and the leakage current is less than 0.1 μA.
Synthesis of Li7La3Zr2O12 Solid Electrolyte by Solid Phase Sintering Method
Authors: Liu Guanghua , Li Tianjun , Xing Yan , Pan Wei 
Published: November 2019

Abstract
Li7La3Zr2O12 (LLZO) is a promising electrolyte material for all-solid-state battery due to its high ionic conductivity and good air stability with metallic lithium. In this article, Li7La3Zr2O12 electrolytes with excess lithium 4wt%, 6wt%, 8wt%, 10wt% were prepared by traditional two steps solid-phase sintering method. The influence of concentration of lithium and calcination temperature on the structure of Li7La3Zr2O12 were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM) in detail. To improve the density of the sample, the granulation was applied. Scanning electron microscopy (SEM) results showed the granulation of Li7La3Zr2O12 power before pressing can significantly accelerate densification during the final high temperature, long duration sintering process.
Extraction of Potassium from Biotite by Lithium Ion Exchange and Its Electrochemical Properties
Authors: Cheng Yilin , Huang Zhiliang , Yao Donghui , Wu Changsheng 
Published: November 2019

Abstract
In order to solve the problem of shortage of potassium resources in China, the technology of extracting soluble potassium from insoluble potassium minerals needs to be further studied. Biotite with relatively high potassium content was used as the research object to extract soluble potassium elements from biotite by lithium ion exchange method, and the electrochemical properties of biotite were tested after potassium extraction. After 80°C hydrothermal reaction for hours, potassium and lithium ion exchanged with each other, and soluble potassium were obtained from the filtrate by filtering the reaction liquid. The efficiency of potassium extraction and the structure of mica changed after the oxidation reaction was determined by XRF and XRD, respectively. The results showed that the layered silicate structure of mica after the reaction was not destroyed, and the potassium extraction rate for 8h was up to 92.3%. The discharge capacitance was 1.32F/g, and the coulomb efficiency was 64% in 0.6C.
Oxidation Behavior of Cu Doped CrAlN Coating Deposited by Magnetron Sputtering at 800°C
Authors: Chang Weijie , Zhang Hao , Li Xiangrui , Huang Chuan , Wang Yulong , Song Lingling , Duo Shuwang 
Published: November 2019

Abstract
CrAlN coating with moderate Cu content was deposited on the surface of 1Cr18Ni9Ti stainless steel by DC reactive magnetron sputtering. The oxidation behavior under 800°C of the coatings was investigated emphatically in this research. The phase construction, microstructure and chemistry contents were analyzed by X-ray diffraction (XRD), field-emission electron scanning microscope (FESEM) and energy disperse spectroscopy (EDS). And the mechanical properties of the coatings were measured by microhardness tester and multi-function scratcher. As a comparison, the properties of CrAlN coating were also analyzed in the article. The results showed that the microstructure of CrAlCuN coating became smother and denser with a phase structure of CrN and Cu. With Cu doped in the CrAlN coating, the more excellent hardness which enhanced to 48.37 GPa was obtained. While the bonding strength of the coating was decreased because of the advanced microhardness usually released more internal stress. Both of the coatings were not complete failure and CrN diffraction peak was also tested. The oxidation rate of weight gain had significantly decreased with Cu doped, which improved the resistance of high temperature oxidation to a certain extent.
Service Time Performance Analysis of Improved Automated Restaurant by Layout Reconfiguration and Conveyor System
Authors: Chin W J , Lim M , Yong J C E , Al-Talib AAM , Chaw K H 
Published: November 2019

Abstract
Achieving effective service time in restaurants hinges on implementing and integrating innovation in design and technology. A combination of restaurant layout configuration and conveyor belt system integration is proposed to enhance the turnaround service time performance. Emphasis on the layout reconfiguration with optimized dining capacity and conveyor system for semi-automated function are applied to existing restaurants by heuristic method. Then operation is simulated by agent-based approach in Anylogic simulator. Results yielded an improved in the total turnaround service time by 2.75% to 5%, which correspond to an approximate 78% reduction on a food-to-table service time. The enhanced performance shows the effectiveness of reconfigured layout to service more customers without compromising delivery time. While conveyor belt mechanism provides the greatest food delivery time and manpower reduction, with a considerable payback period of 6 months. The findings and modelling will aid the implementation of semi-automated restaurant as a stepping stone to one fully automated.
Design of Storage and Monitoring System for Medical Dangerous Chemicals Based on Wireless Sensor Network
Authors: Zhang Tao , Xu Ren-Ren , Zhang Ya-Wei , Meng De-Qiang 
Published: November 2019

Abstract
Medical hazardous chemicals storage system is a special storage system. Its management basically relies on getting rid of a lot of manpower and increasing the safety and reliability of management. Using information management is a necessary way to improve storage efficiency, reduce storage cost and improve storage security. This design adopts wireless sensor network technology according to the characteristics of storage system of medical dangerous chemicals (Wireless Sensor Networks, WSNs). The wireless sensor network node design scheme is proposed. Based on IEEE802.15.4/ZigBee protocol, the wireless sensor network node is designed and implemented by PIC18F4620 single chip microcomputer and wireless radio frequency chip CC2420. Realize low cost to improve the security and real-time of monitoring, realize information sharing and network remote monitoring.
Planning Path Strategy and Simulation of Infusion Service Robot Based on Ant Colony Algorithm
Authors: Zhang Tao , Meng De-Qiang , Zhao Su-Dong 
Published: November 2019

Abstract
The infusion service robot was taken as the research object, and the algorithm of path planning for infusion service robot was simulated by the sensor network system in this experiment. The ant colony algorithm was selected based on the sensor network node optimization deployment of the mobile service robot. Based on sensor network for hospital environmental information collection, combined with sensor network node information and RSSI algorithm based on MATLAB to achieve positioning, and then complete the simulation study of infusion service robot navigation. The ant colony algorithm was verified as the basic method and feasibility of applying the path strategy of the robot platform. During the testing process, some conditions and algorithms were simplified to avoid the complexity of the problem.
Calculation of Parameters of the Cryogenic Rotor-Blade Engine for the Drive of the Refrigeration Unit for Truck
Authors: Uglanov D , Tereshchenko O , Zaika S , Neverov I , Panshin R 
Published: November 2019

Abstract
Cars with internal combustion engines using hydrocarbon fuels occupy the main market share. The cost of these products is increasing, and this negatively affects the prosperity of the population and the cost of freight transportation. The growth in energy consumption and the rapid growth of cars deplete non-renewable natural oil and gas resources, leading to intense combustion of atmospheric oxygen.
One of the promising types of environmentally friendly engine is a cryogenic fuel engine. Such engines have higher energy performance and lower cost in comparison with electric vehicles, and their operating costs are comparable with traditional cars, taking into account the ecological aspect.
The study presents the development of methods for calculating the rotor-blade engine and its design. Since refrigeration plants consume 3% of the internal combustion engine power, it is advisable to replace them with autonomous units using a cryogenic working fluid, thereby reducing emissions of harmful substances into the atmosphere.
Automobile Connecting Rod Forging Optimization Based on DEFORM and Orthogonal Experiment
Authors: Hong-wei XU , Yan-bo JING , Xiao-ming QI , Shou-dong LI , Dou-wei LIU 
Published: November 2019

Abstract
Taking blank temperature, mould temperature and friction coefficient as test factors, the orthogonal experiment of three factors and three levels of automobile connecting rod forging was designed. Using Deform-3d, the forging experiment under different factors is simulated, and the forging results under different technological parameters were obtained. The process parameters of connecting rod forging are optimized by using the comprehensive measurement method and taking deformation uniformity and maximum forming load as indexes. The results show that the optimized process parameters can reduce the forming load and improve the deformation uniformity.