bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigation of processing factors affecting flexible heating wire by coating polyester yarns with carbon nanotubes
Authors: Xiao Y , Zhang L R , Li L X 
Published: March 2020

Abstract
A method for preparing a flexible heating wire coated with carbon nanotubes on a surface of a polyester yarn is proposed in view of the problems of poor flexibility and water washing resistance of the existing heating wire. Based on the flexible heating wire forming system, the orthogonal test method was used to study the effects of process parameters such as solution concentration and polymer content on the formation of flexible heating wire; the prepared heating wire was subjected to resistance measurement, microscopic morphology observation, heating and washing resistance tests. The results show that the optimal parameter parameters for the preparation of flexible hot wire is A3B3C2D2. In this combination, the polymer content is 15 g/L and the heating wire resistance is 180.5 Ω/cm. Moreover, the photomicrograph shows that the surface has a conductive layer composed of polymer and carbon nanotubes, which has no obvious protrusions and breaks; the surface of the parallel mesh structure can obtain a heating temperature of 52.2°C at a voltage of 12 V; the resistance of heating wire does not increase with latter washing after the first washing.
Application of confocal 3D-MXRF technology to the 3D elemental analysis and surface topography imaging of samples
Authors: Xiang Z J , Meng Z Y , Liu Z G , Pan K , Zhao W G , Zhou P , Li Y 
Published: March 2020

Abstract
X-ray fluorescence analysis technology (XRF) is widely used in many fields. In this experiment, a three-dimensional confocal microbeam X-ray fluorescence analysis (3D-MXRF) spectrometer built by the laboratory is used to perform deep scanning on single element sample, surface coated sample, and ceramic sample, etc., the new spectrometer has deeper probing depth and better ability to resolve adjacent elements in the sample. The distribution of three-dimensional elements of samples is analyzed and explained. And the surface topography imaging of two samples is performed, and the newly constructed confocal 3D-MXRF was found to have a higher microscopic resolution, which plays a potential role in the popularization of surface inspection and 3D element analysis of industrial products.
Effect of SnO2 content on properties and microstructure of Ag/SnO2 electric contact materials
Authors: Wang J B , Qiu H H , Si F , You Y B , Liu S T , Matsumoto N H 
Published: March 2020

Abstract
In order to explore the effects of SnO2 content on the properties and microstructure of Ag/SnO2 electric contact materials with low silver content. A series of Ag/SnO2 electric contact materials with different SnO2 content were prepared and their arc erosion properties and physical properties were tested. The results show that with the decrease of Ag content, the hardness of Ag/SnO2 contact materials increases, and the conductivity and density decrease. When the Ag content is 88%, Ag and SnO2 enrichment zones are formed on the surface of the Ag/SnO2 contact material after arc erosion test. When the silver content is less than 82%, the surface microstructure of the Ag/SnO2 contact material after arc erosion is uniform, and no obvious Ag and SnO2 enrichment zones were formed, but cracks and pores increased.
Hardening and precipitation of a commercial 6061 Al alloy during natural and artificial ageing
Authors: Chen Y , Lu B Q , Zhang H A 
Published: March 2020

Abstract
In this study, the precipitation and hardening of a commercial 6061 Al alloy during the combined natural and artificial ageing are analyzed, in order to maximize the alloy hardness by adjusting ageing time and temperature. The samples were solution-treated at 540°C for 2 hours, followed by water quenching. An artificial ageing was performed at 180, 200, and 220°C during a period from 2 min to 12 h. Natural ageing at room temperature during 12 h was performed simultaneously with the artificial one at different elevated temperatures. The Vickers hardness values of solution-treated and aged samples were measured. Precipitates were characterized via the X-ray diffraction and scanning transmission electron microscopy equipped with the energy dispersive X-ray spectroscopy. The highest hardness values were exhibited by samples that were naturally aged for 12 hours and artificially aged for 24 hours at 200 and 220°C. The hardness improvement was found to be controlled by the formation of β” phases before the peak ageing.
State-of-the-art applied research on conductive composites
Authors: Hu C Q , Huang Y M , Yang J S , Yu Q , Sun M 
Published: March 2020

Abstract
The article introduces the types of conductive composites and analyzes several kinds of their conductive mechanisms based on the percolation theory, quantum tunneling effect, effective medium, and field emission theory. The current research progress concerning the effects of conductive materials’ matrix, conductive fillers, and doping on them is discussed in detail. Available preparation methods and applications of conductive composite materials are summarized. A future research direction on the refinement of conductive composites is outlined, which implies the development of new matrix systems and conductive fillers with higher and more stable electrical conductivity.
Construction and application of a micro-area polarized energy dispersive X-ray fluorescence spectrometer with polycapillary X-ray lens in a conventional laboratory
Authors: Zhou M , Li Y D , Wang X Y , Duan J Y , Luo H , Ye L , Lin X Y 
Published: March 2020

Abstract
The polarized energy dispersive X-ray fluorescence analysis method can effectively reduce detection limits by improving the signal-to-noise ratio. However, the lack of high-power density and small analysis area of the polarized X-ray beam has hindered more accurate analysis of samples in conventional laboratory. A polycapillary X-ray lens can be applied to micro-area analysis. Therefore, a micro-area polarized energy dispersive X-ray fluorescence spectrometer based on a bent highly oriented pyrolytic graphite and a polycapillary X-ray lens is proposed. The polarization degree of the polarized X-ray beam is 99.76% and its focal spot size is 338.8 μm × 404.5 μm. The new spectrometer feasibility was proved by effective production of high-resolution element distribution maps of a holly (Ilex chinensis Sims) leaf sample.
Corrosion evolution of electric power equipment metal materials under industrial pollution environment with high heat and high humidity
Authors: Ren X , Zhong Y , Hao J , Wu G L , Wang Q 
Published: March 2020

Abstract
To investigate the atmospheric corrosion characteristics of metal materials of electric equipment in the atmospheric environment with high humidity and high chlorine industrial pollution, atmospheric accelerated corrosion tests of a typical power metal Q235 carbon steel and galvanized steel were carried out by the salt spray method. The corrosion kinetics, corrosion products, and morphology of both materials were investigated by the weight loss method, scanning electron microscopy (SEM), and X-ray diffraction (XRD). The corrosion rate of carbon steel is larger than that of galvanized steel, and both drop with time. NaHSO3 promotes the formation of α-FeOOH in the corrosion process of carbon steel. The high-humidity and high-chlorine environment is not conducive to the formation of Fe3O4. The interaction of NaHSO3 and NaCl promotes the generation of corrosion products, mainly NaZn4SO4(OH)6Cl·6H2O, in galvanized steel by pitting corrosion.
Study on microstructure and texture of high-strength plastic cold-rolled dual-phase DP980 steel
Authors: Wang W W , Liu L , Li G Y 
Published: March 2020

AbstractIn order to improve the strength and plasticity of cold-rolled dual-phase DP980 steel, the relationship between process structure and properties were systematically studied by adjusting continuous annealing process parameters. The microstructure, recrystallized grains, phase distribution, and texture of different phases at different annealing temperatures were analyzed by OM, SEM, and EBSD. At the same time, the effect of continuous annealing temperature on the strength and plasticity were studied by mechanical tensile tests. The results obtained show that by optimizing and adjusting the continuous annealing process, not only a small amount of residual austenite can be obtained on the structure of cold rolled ferrite and martensite dual phase steel, but also recrystallized grains can be refined. Finally, cold-rolled DP980 steel with YS/TS < 0.5 and high elongation A50 < 15% can be obtained, and its strength/plasticity balance can be increased to 15-20 GPa%, which is also favorable for its formability.
Geometric accuracy of rapid prototyping technologies using laser scanner and coordinate measurement machine
Authors: Dardzinska A , Fiedorczuk K 
Published: March 2020

Abstract
In this paper we present a prototyping method used in medical data. 3D printing technology is extremely important, especially in medical area. Using 3D printing in preoperative treatment planning seems to be a proper solution in personalized medicine, contributing to improving healthcare system quality. Medical measurements methods on living bones, with respect to their natural environment are still unknown, the basic research includes mainly the measurement of landmarks using a digital caliper, where the linear measurement is taken between the marked points. Another way is to use a coordinate measuring machine. Most often, the accuracy measurement methods are based on marking landmarks on the object, which are collected by a machine, and then performs coordinate measurements of points. In our research we focus not on individual points of the model but on the measurement of whole objects, we prepared materials, and printed the model in 3D technology in different technologies and on different devices: FDM, PJ, SLM. On the basis of our work we conclude there is no best RP technique for making medical models. Due to the criterion of model accuracy, PolyJet is one of the most suitable technologies for medical modelling. The CJP method is the most appropriate for the cost of making a model. Due to the type of material the FDM method is the most suitable for medical applications. 3D printing technologies provide physicians, engineers and scientists with the ability to create customized solutions for a variety of conditions.
Gold nanoparticle-enhanced amplified spontaneous emission of laser dye molecules in diode-pumped organic solid-state lasers
Authors: Lin W J , Li Y L , Lan W X , Liu K P , Wei B 
Published: March 2020

Abstract
Gold nanoparticles (AuNPs) were introduced to enhance surface-amplified spontaneous emission of laser dye molecules, 4-(dicyanomethylene)-2-t-butyl-6(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) doped N,N’-bis-(1-naphthyl)-N,N’-diphenyl-1,1’-biphenyl-4,4’-diamine (NPB), taking advantage of localized surface plasmonresonance (LSPR) effect and scattering effect. With emission received from the back surface of the substrate, the optically pumped gain medium with AuNPs, exhibits higher peak intensity, lower threshold, and better Q-factor of when compared with the neat gain medium without AuNPs. Moreover, to realize an organic solid-state laser pumped by electroluminescence emission in an integrated organic light emitting diode (OLED), NPB: DCJTB was embedded as color conversion-hole transport layer (CC-HTL). The AuNPs deposited on the ITO glass substrate of the OLED were also employed to enhance the photoluminescence of the CC-HTL. The maximum luminance, current efficiency and power efficiency improved by 21.55%, 21.90% and 42.11% at 150 mA/cm2 of AuNPs-OLED, respectively, compared to the OLED without AuNPs. These results were attributed to the enhanced hole injection caused by AuNPs as well as LSPR and scattering effects. The introduction of AuNPs provides a simple and promising method to realize diode-pumped organic solid-state lasers.
Experimental study and statistical analysis on corroded steel bars
Authors: Chang Y , Zhang L F , Gao P W , Tian Y L 
Published: March 2020

Abstract
Bearing capacity and durability of corroded steel bars is strongly deteriorated, and the degradation of mechanical properties versus corrosion ratio is topical. Given the random nature of corrosion process, stochastic method can be used to describe mechanical performance of corroded steel bars. In this paper, to simulate marine tidal zone environment, steel bars corroded by chloride solution under dry-wet cycling are studied experimentally, while mechanical performance deterioration of corroded steel bars is analyzed statistically. The corrosion ratios of specimens are found to increase over time for several phases, while their strength dropped with corrosion ratio. The residual nominal strength to corrosion ratio of steel bars is found to be well fitted with the Gumbel distribution, which parameters are calculated and discussed in detail.
Study on microstructure and mechanical properties of as-cast Mg-Zn-Sn-xCu(x=0,0.5,1.0,1.5wt.%) alloys
Authors: Liu Y H , Ma M L , Zhang K , Li X G , Li Y J , Shi G L , Yuan J W 
Published: March 2020

Abstract
In this paper, with the help of optical microscope, X-ray diffraction, scanning electron microscope and mechanical testing machine, the microstructures of ZT63-xCu (x=0,0.5,1.0,1.5wt.%) magnesium alloys were investigated and their mechanical properties were explored. It was found that the structure of as-cast alloys presented a typical dendrite morphology. The eutectic structure was refined by the addition of a certain amount of Cu, When Cu content continued to increase, the volume fraction of the eutectic structure increased and its continuity enhanced. The alloy without Cu addition was composed of α -Mg, MgZn2 and Mg2Sn phases. With the addition of Cu elements, MgZnCu phase was formed in the alloy, in addition to α-Mg, MgZn2 and Mg2Sn phases. With the increase of Cu content, the volume fraction of MgZnCu phase increased, and the proportion of MgZn2 phase gradually decreased. ZT63 alloy had the best matching of mechanical properties, its tensile strength and yield strength were 231Mpa and 80Mpa respectively, and the elongation reached 14.5%. With the increase of Cu, the mechanical properties of the alloys declined. When the Cu content is 1.5wt.%, tensile strength of the alloy decreased to 174Mpa, and the elongation was only 7%. The reduction of mechanical properties was related to the increase of MgZnCu phase.
Effect of Al content on the microstructure and mechanical properties of Mg-5wt%Sn-xAl as-cast alloys
Authors: Sun Z Q , Li Y J , Zhang K , Li X G , Ma M L , Shi G L , Yuan J W 
Published: March 2020

Abstract
Microstructure and mechanical properties of Mg-5wt.% Sn-xAl as-cast alloys were studied, for the Al content ranged from 0.5 to 3.0wt.%. It was found that Al element was mainly distributed in Mg17Al12 phase in as-cast alloys, and its increase rose the Mg17Al12 phase share. There were no ternary phases in these alloys. Only two forms of Mg2Sn and Mg17Al12 phases were detected, namely (i) Mg17Al12 phase attached to the end of Mg2Sn phase and (ii) Mg2Sn phase enclosed by Mg17Al12 phases. The grain sizes of these alloys got refined with the growing content of Al element, and 1.5wt% Al content corresponded to the grain size of 33.5um. As for the mechanical properties, the ultimate tensile and yield strengths of the alloys were improved at larger contents of Al. The Mg-5wt.%Sn-3.0wt% alloy had the highest ultimate tensile and yield strengths of 212 and 167MPa, respectively, while Mg-5wt.%Sn-1.5wt%Al alloy had the best elongation of 16.5%.
Effect of heat treatment on the electrical conductivity of ZM51 magnesium alloy
Authors: Yuan J W , Mu T , Zhang K , Li X G , Zhang K , Li Y J , Ma M L , Shi G L 
Published: March 2020

Abstract
The microstructures and electrical conductivity of extruded Mg-5.38 wt.%Zn-0.88 wt.%Mn (ZM51) magnesium alloys under four different heat treatments (T5: single aging, two-stage aging; T6:T4+single aging, T4+two-stage aging) were investigated by optical microscopy (OM), X-ray diffraction (XRD), transmission electron microscopy (TEM) and conductivity test. The results show that the electrical conductivity of alloys after different heat treatments was increased with the aging time increasing identically. The conductivity of T6 ZM51 alloy is lower than that of T5 treatment alloy, and the conductivity of alloy with two-stage aging is higher than that of alloys with single-stage aging. In the two-stage aging, the time of pre-aging at low temperature formed dense GP zones which can serve as the nucleation core of the β1’ phases, and the formed β1’ phases are more diffuse and fine, and the scattering of free electrons are lower. The electrical conductivity of the alloy increased first and then reduced with the increase of the pre-aging time, and the reason is that the alloys form a more diffuse GP zones after pre-aging for 32h, which can be used as the heterogeneous nucleation core of β1’ phases, so that the precipitation of the β1’ phases are more finely dispersed, thereby increasing the scattering capacity of free electrons.
An explicit simulation of arbitrarily-shaped pseudo-elastic hysteresis loops in shape-memory alloys
Authors: Wang S Y , Zhan L , Xu Z H , Xi H F , Xiao H 
Published: March 2020

Abstract
A new and explicit approach is proposed for accurately simulating pseudo-elastic hysteresis loops of any shape in shape-memory alloys (SMAs). For this purpose, new finite strain elastoplastic J2-flow equations are established for modeling finite strain behavior of SMAs. A stress-strain loop of any given shape in each uniaxial loading-unloading cycle is derived exactly from these equations. Then, a new technique is further introduced toward integrating usual piecewise linear splines into a single smooth interpolating function in a unified form. With the proposed equations and technique, test data for SMA hysteresis loops of any shape may be automatically fitted with high accuracy based on a single-parameter identification.
Explicit and accurate characterization of hardening- softening behavior of metals up to failure
Authors: Xu Z H , Wang S Y , Zhan L , Xi H F , Xiao H 
Published: March 2020

Abstract
Full and accurate characterization of metal hardening-softening effects till failure is carried out with a new explicit approach. To this purpose, a new expression for the plastic work is presented explicitly in terms of the uniaxial stress-strain function of any given form. Accordingly, the yield strength as function of the plastic work can be determined jointly from the above functions with the axial logarithmic strain as parametric variable. Using the proposed approach, any test data obtained within the entire stress-strain range with hardening and softening portions up to failure can be fitted by directly treating a suitable form of the uniaxial stress-strain function. This allows one to bypass usual tedious trial-and-error numerical procedures in dealing with nonlinear elastoplastic rate equations for identifying numerous unknown parameters. Accurate simulation results are shown with numerical examples.
A unified simulation of low-to-high cycle fatigue failure effects for metals with efficient algorithm
Authors: Zhan L , Wang S , Xu Z H , Xi H F , Xiao H 
Published: March 2020

Abstract
Within the framework of a recently established elastoplasticity model incorporating fatigue failure effects into inherent response features, a new and efficient algorithm is proposed to simultaneously treat fatigue failure effects from low to high cycle cases. From the new model it is possible to derive an explicit algorithm with which the accumulated plastic work is directly calculated by means of a recursive scheme, thus bypassing very time-consuming procedures in carrying out numerical integrations of the elastoplastic rate equations for a large number of loading-unloading cycles. Comparisons of simulation results with fatigue failure data from low to high cycle cases are presented to demonstrate the efficacy of the new algorithm.
A unified and explicit approach for accurately characterizing the hardening-softening behavior of metals with a tension-compression strength asymmetry
Authors: Xi H F , Zhan L , Wang S Y , Xu Z H , Xiao H 
Published: March 2020

Abstract
A unified and explicit approach is proposed for accurately characterizing a complex hardening-softening behavior of metals with a tension-compression strength asymmetry. The proposed approach provides an explicit determining of the yield strength as plastic work function and contains the following three procedures: (i) a mode invariant is introduced to express the yield strength as a sum of two uncoupled parts for the tension and the compression case; (ii) a new expression for the plastic work is derived explicitly in terms of the uniaxial stress-strain function and, then, the yield strength function can be determined jointly from the just-mentioned two functions with the axial strain as parametric variable; and, finally, (iii) the axial stress-strain function is presented for representing the hardening-softening features. With these procedures, test data over the entire hardening-softening range can be fitted independently for the tension and the compression cases by directly treating the uniaxial stress-strain function. As such, tedious trial-and-error procedures are bypassed in identifying numerous unknown parameters. Numerical examples show that accurate simulations may be achieved with the proposed approach.
A flexible tactile sensor using seedless hydrothermal growth of ZnO nanorods on fabrics
Authors: Hong Gwang-Wook , Kim Jihyun , Lee Jun-Soo , Shin Kyeongho , Jung Dongsoo , Kim Joo-Hyung 
Published: March 2020

Abstract
A flexible and cost-effective electromechanical device for tactile sensing based on ZnO nanorods (ZnO NRs) grown on fabrics is developed. Sensing performance and the electromechanical properties of ethylcellulose/polyurethane-coated ZnO NRs on fabric substrates were tested by the LCR meter, force transducer, vibrator, and pulse analyzer. The peak-to-peak output voltage at an applied force of 21.5 N dropped considerably for the wool-, nylon-, and PP substrates and reached to the order of 3.84 mV, 1.8 mV and 4.1 mV, respectively. Furthermore, the frequency dependency of the dissipation factors revealed abrupt changes at low frequencies, while these changes were negligible at high frequencies.