33 results on '"Haiyang Zhou"'
Search Results
2. Mechanical Properties and Fire Retardancy of Wood Flour/High-Density Polyethylene Composites Reinforced with Continuous Honeycomb-Like Nano-SiO2 Network and Fire Retardant
- Author
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Haiyang Zhou, Wang Xiaoyu, Qingwen Wang, Rongxian Ou, and Xiaolong Hao
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Materials science ,Materials Science (miscellaneous) ,Honeycomb ,Wood flour ,Environmental Science (miscellaneous) ,Composite material ,Fire retardant - Published
- 2020
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Catalog
3. Long-time measurements of line-integrated plasma electron density using a two-color homodyne optical fiber interferometer
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A.D. Liu, Chijin Xiao, Hangqi Xu, Weixing Ding, Zian Wei, Shijie Lan, Junfeng Zhu, Hong Li, Defeng Kong, Yao Yuan, Chu Zhou, Xiaohui Wen, Chen Chen, Jie Wu, Tao Lan, Hai Wang, Zhengwei Wu, Sen Zhang, Jiaren Wu, Ge Zhuang, Yiming Zu, Wandong Liu, Shoubiao Zhang, Peng Yuan, Jinlin Xie, Haiyang Zhou, Tijian Deng, and Wenzhe Mao more...
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Electron density ,Materials science ,Optical fiber ,business.industry ,Resolution (electron density) ,Astrophysics::Instrumentation and Methods for Astrophysics ,Physics::Optics ,Torus ,Plasma ,law.invention ,Interferometry ,Wavelength ,Optics ,law ,Demodulation ,business ,Instrumentation - Abstract
A two-color homodyne Mach–Zehnder (M–Z) optical fiber interferometer with wavelengths of 1.55 and 1.31 µm was developed for long-time measurement of line-integrated plasma electron density. A novel phase difference demodulation algorithm based on a single 3 × 3 optical coupler was implemented in a two-color optical fiber interferometer scheme for the first time. Our laboratory tests showed that this new optical fiber interferometer could determine the phase shift due to the low-frequency ambient vibration and could maintain high phase resolution measurement. The resolution of the new interferometer was less than 0.04 rad in 1000 s, corresponding to a line-averaged electron density of less than 1.0 × 1019 m−2. Actual plasma discharge experiments performed on KTX-CTI, which is a new compact torus injector (CTI) constructed at the Keda Torus eXperiment (KTX), showed that this interferometer has excellent several-second stability. more...
- Published
- 2021
4. Effects of SiO2 Filler in the Shell and Wood Fiber in the Core on the Thermal Expansion of Core–Shell Wood/Polyethylene Composites
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Rongxian Ou, Haiyang Zhou, Guanggong Zong, Lichao Sun, Xiaolong Hao, Qiong Guo, Junjie Xu, and Qi Fan
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0106 biological sciences ,Materials science ,Polymers and Plastics ,Shell (structure) ,core–shell structure ,02 engineering and technology ,engineering.material ,01 natural sciences ,wood plastic composites ,Thermal expansion ,Article ,lcsh:QD241-441 ,chemistry.chemical_compound ,lcsh:Organic chemistry ,010608 biotechnology ,Filler (materials) ,Fiber ,Composite material ,Anisotropy ,thermal expansion ,co-extrusion ,General Chemistry ,Polyethylene ,021001 nanoscience & nanotechnology ,Core (optical fiber) ,chemistry ,silica ,engineering ,0210 nano-technology ,Layer (electronics) - Abstract
The influence of nano-silica (nSiO2) and micro-silica (mSiO2) in the shell and wood fiber filler in the core on the thermal expansion behavior of co-extruded wood/polyethylene composites (Co-WPCs) was investigated to optimize the thermal expansion resistance. The cut Co-WPCs samples showed anisotropic thermal expansion, and the thermal expansion strain and linear coefficient of thermal expansion (LCTE) decreased by filling the shell layer with rigid silica, especially nSiO2. Finite element analysis indicated that the polymer-filled shell was mainly responsible for the thermal expansion. The entire Co-WPCs samples exhibited a lower thermal expansion strain than the cut Co-WPCs samples due to protection by the shell. Increasing the wood fiber content in the core significantly decreased the thermal expansion strain and LCTE of the Co-WPCs. The Co-WPCs whose core layer was filled with 70% wood fiber exhibited the greatest anisotropic thermal expansion. more...
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- 2020
5. Optical fiber interferometer application for high electron density measurements on compact torus plasmas
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Hangqi Xu, Xiaohui Wen, Hong Li, Weixing Ding, Sen Zhang, A.D. Liu, Junfeng Zhu, Yiming Zu, Shoubiao Zhang, Hai Wang, Defeng Kong, Wandong Liu, Jiaren Wu, Yao Yuan, Jie Wu, Z. X. Liu, Haiyang Zhou, Zian Wei, Ge Zhuang, Chen Chen, Tao Lan, Tijian Deng, Wenzhe Mao, Jinlin Xie, Shijie Lan, and Chijin Xiao more...
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Accuracy and precision ,Optical fiber ,Materials science ,business.industry ,Astrophysics::Instrumentation and Methods for Astrophysics ,Physics::Optics ,Torus ,Plasma ,law.invention ,Time of flight ,Interferometry ,Wavelength ,Optics ,law ,Phase noise ,business ,Instrumentation - Abstract
An optical fiber Mach-Zehnder interferometer at a wavelength of 1.55 µm has been developed for measurements of high electron density on compact torus (CT) plasmas with a high time resolution of 0.1 µs and high phase resolution of 6.4 × 10-4 rad. To improve density measurement accuracy, the phase noise of the interferometer has been investigated in detail and optimized. In the bench test, the interferometer was calibrated using a piezoelectric ceramic actuator with known stroke. Initial results on CT plasma show that the optical fiber interferometer provides reliable density measurements at two spatial locations and the bulk velocity of plasma can be determined by the method of time of flight. more...
- Published
- 2020
6. Microstructure versus size: nano/microscale deformation of solute-strengthening Al alloys via pillar compression tests
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Qing H. Qin, Haiyang Zhou, and Shaohua Yan
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Materials science ,compression test ,Physics::Optics ,02 engineering and technology ,mechanical properties ,Deformation (meteorology) ,01 natural sciences ,Physics::Fluid Dynamics ,Condensed Matter::Materials Science ,0103 physical sciences ,Nano ,lcsh:TA401-492 ,General Materials Science ,Composite material ,Microscale chemistry ,010302 applied physics ,dislocation ,Pillar ,Solutes strengthening ,021001 nanoscience & nanotechnology ,Microstructure ,Compression (physics) ,Computer Science::Other ,Compression test ,lcsh:Materials of engineering and construction. Mechanics of materials ,Dislocation ,0210 nano-technology - Abstract
Effect of solutes, crystal orientation, sample’s size, and dislocation density on the nano/microscale deformation of solute-strengthening Al alloys has been investigated via pillar compression tests. The Mg-solute-strengthening pillar with dislocation density of 1012 m−2 shows size- and orientation-dependent strength, while the strength of Si-Mg-solute-strengthening pillar with dislocation density of 1013 m−2 is size- and orientation- independent. With increasing the dislocation density, the strength of pillars increased and become size-independent. Links between the microstructure, sample’s size and nano/microscale plasticity of solute-strengthening Al alloys were made via pillar compression testing. Deformation mechanism at nano/microscale was quantitatively explored. more...
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- 2018
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7. Crystal plasticity in fusion zone of a hybrid laser welded Al alloys joint: From nanoscale to macroscale
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Qing H. Qin, Shuang Zhang, Haiyang Zhou, Li Li, Bobin Xing, and Shaohua Yan
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010302 applied physics ,Materials science ,Fusion zone ,Mechanical Engineering ,02 engineering and technology ,Welding ,Plasticity ,021001 nanoscience & nanotechnology ,Laser ,01 natural sciences ,law.invention ,Crystal plasticity ,Mechanics of Materials ,law ,0103 physical sciences ,lcsh:TA401-492 ,General Materials Science ,lcsh:Materials of engineering and construction. Mechanics of materials ,Microplasticity ,Composite material ,0210 nano-technology ,Nanoscopic scale ,Joint (geology) - Abstract
In this paper, we propose a novel approach to predict the plasticity of hybrid laser welded Al alloys joints based on the microplasticity obtained from the micropillar compression test. The micropillar test was performed on the single-crystal pillar with three orientations and various diameters (400 nm to 6.8 μm). It was found that independent of orientation, the yield strength of the pillar increased with the decrease of diameter below a critical length (3.3 μm). A numerical model was successfully built and used to explain the size effect on the pillar's strength. Crystalline orientation did affect the yield strength, the orientation having higher Schmid's factor showing lower yield strength, but the effect was reduced with the enlarged diameter. The macroscale yield strength achieved from crystal plasticity finite element simulation showed was found to have a good agreement with that from the experiment. The results here shed new insights both on the application of the micropillar study of alloys, and on prediction of strength in welded Al alloys joint. Keywords: Size effect, Nano/micropillar compression, Crystal plasticity, Multiscale study, Hybrid laser welding more...
- Published
- 2018
8. Effect of filling materials on the microstructure and properties of hybrid laser welded Al-Mg-Si alloys joints
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Qing-Hua Qin, Hui Chen, Shaohua Yan, Bobin Xing, Haiyang Zhou, and Yi Xiao
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010302 applied physics ,Materials science ,Mechanical Engineering ,Laser beam welding ,02 engineering and technology ,Welding ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Microstructure ,Laser ,01 natural sciences ,Fatigue limit ,law.invention ,Corrosion ,Mechanics of Materials ,law ,0103 physical sciences ,Ultimate tensile strength ,General Materials Science ,Composite material ,0210 nano-technology ,Joint (geology) - Abstract
A serious investigation was conducted to examine the influence of filling materials on the microstructure and properties of hybrid laser welded AA6061-T6 joints. The results of the tensile tests showed that the welded joint with ER4043 filling materials had higher tensile strength than that with ER5356 filling material. Based on the results obtained a strength model was built to predict and explain the enhancement of the yield strength of the hybrid laser welded AA6061-T6 joint with different welding wires. In contrast to the tensile strength, the ER4043 joint showed lower fatigue strength than that of the ER5356 joint due to extensive presence of micropores in fusion zone. Further, the corrosion experiment illustrated that the ER4043 joint had poorer resistance to the corrosive attack under 3.5% NaCl solution. A summary was made on the performance of both welded joints to shed new insights on selecting appropriate filling materials when welding AA6061-T6 by hybrid laser welding method. more...
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- 2018
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9. Mechanical reinforcement and creep resistance of coextruded wood flour/polyethylene composites by shell‐layer treatment with nano‐ and micro‐SiO 2 particles
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Haigang Wang, Yanjun Xie, Xiao Zefang, Qingwen Wang, Hao Xiaolong, and Haiyang Zhou
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Materials science ,Polymers and Plastics ,0211 other engineering and technologies ,Shell (structure) ,Wood flour ,02 engineering and technology ,General Chemistry ,Polyethylene ,021001 nanoscience & nanotechnology ,chemistry.chemical_compound ,chemistry ,Creep ,021105 building & construction ,Nano ,Materials Chemistry ,Ceramics and Composites ,Composite material ,0210 nano-technology ,Reinforcement ,Layer (electronics) - Published
- 2018
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10. Qualitative and quantitative analysis of misaligned electrode degradation when welding galvannealed steel
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Shaohua Yan, Bobin Xing, Hua Chen, Qing-Hua Qin, and Haiyang Zhou
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0209 industrial biotechnology ,Materials science ,Mechanical Engineering ,02 engineering and technology ,Welding ,engineering.material ,021001 nanoscience & nanotechnology ,Microstructure ,Industrial and Manufacturing Engineering ,Computer Science Applications ,Galvannealed ,law.invention ,020901 industrial engineering & automation ,Coating ,Control and Systems Engineering ,law ,Heat generation ,Electrode ,engineering ,Composite material ,0210 nano-technology ,Spot welding ,Software ,Electron backscatter diffraction - Abstract
Electrode misalignment, induced from the flexibility of welding machine gun of spot welder or the potential poor fit-up, leads to the high tendency of expulsion and asymmetric nugget shape. Yet very few studies have focused on the influence of misalignment on the electrode degradation and microstructure evolution of the electrode, especially when welding galvannealed steel. This paper investigates the degradation of such misaligned electrodes when spot welding galvannealed steel. To reveal its mechanism, the electrodes welded with galvannealed steel were examined after 10 and 200 welds with the slight misalignment. The electrodes were found to experience more severe degradation compared to the results from previous studies with the aligned electrodes. The results from energy-dispersive spectrum (EDS) analysis further confirmed that δ-Fe–Zn phase, a barrier from galvannealed coating for isolating Cu and Zn formation, was not uniformly distributed on the electrode tip. As a result, the initial electrode pitting took place after 50 welds. Furthermore, electron backscatter diffraction (EBSD) quantitatively analyzed the recrystallized grains of the worn electrodes, which underwent rotation under the asymmetric pressure distribution under misalignment. The calculated Taylor factor via EBSD mapping also indicated the declined portion of grains accounted for the low deformation resistance of the worn electrode. Finally, electrode displacements were simultaneously collected in the experiments, of which the peak values accurately predicted the heat generation for each spot weld and accordingly predicted the electrode life. more...
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- 2018
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11. Sandwich-structured wood flour/HDPE composite panels: Reinforcement using a linear low-density polyethylene core layer
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Xiaolong Hao, Yanjun Xie, Hailong Mu, Haiyang Zhou, and Qingwen Wang
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Absorption of water ,Materials science ,Composite number ,Izod impact strength test ,Wood flour ,02 engineering and technology ,Building and Construction ,Polyethylene ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Linear low-density polyethylene ,chemistry.chemical_compound ,chemistry ,Flexural strength ,General Materials Science ,High-density polyethylene ,Composite material ,0210 nano-technology ,Civil and Structural Engineering - Abstract
Sandwich-structured panels, composed of two surface layers of wood flour/high-density polyethylene composite (WPC) and a core layer of linear low-density polyethylene (LLDPE), were prepared by hot-press. The single-layer WPC panels were used as controls, with wood flour contents ranging from 55 to 84%. The sandwich-structured panels showed an improvement in both flexural and impact strength of up to 42% and 77%, respectively, and water absorption was considerably reduced compared to the controls. The LLDPE core layer did not cause substantial change in creep and relaxation behavior, but resulted in an increase in the linear coefficient of thermal expansion. more...
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- 2018
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12. In situ measurement of stem water content and diurnal storage of an apricot tree with a high frequency inner fringing dielectric sensor
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David A. Grantz, Yurui Sun, Lutz Damerow, Guilin Shan, B. Chen, B. Wen, P. Schulze Lammers, Haiyang Zhou, Qiang Cheng, and Xuzhang Xue
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0106 biological sciences ,Canopy ,Atmospheric Science ,Global and Planetary Change ,Materials science ,Computer simulation ,HFSS ,Forestry ,Soil science ,04 agricultural and veterinary sciences ,Dielectric ,01 natural sciences ,Core (optical fiber) ,Hysteresis ,Frequency domain ,040103 agronomy & agriculture ,0401 agriculture, forestry, and fisheries ,Agronomy and Crop Science ,Water content ,010606 plant biology & botany - Abstract
Stem water content (StWC) is a key parameter characterizing plant water relations. However, a reliable yet non-invasive method of determining StWC in trees has not been developed. Here we examined an inner fringing frequency domain (FD) sensor in a 12-year old apricot tree. Two strap rings operating at 100 MHz accurately measured StWC in stems 4–12 cm in diameter. Effective sensing depth (ESD) inside the stems, and the allowable maximum stem diameter (AMStD) were systematically evaluated. To determine ESD, a novel experimental method, stepwise stem core removal (SStCR), was developed, and combined with numerical simulation using a High Frequency Structure Simulator (HFSS). The experimental and analytical approaches were in good agreement, demonstrating that the ESD must include substantial sapwood. In apricot, with ring-porous distribution of xylem vessels, performance was excellent up to AMStD ≤ 8 cm following temperature correction. In the current study, we characterize diurnal patterns of water loss and recharge in stems of varying diameter, demonstrate hysteresis in water content between stems of different sizes and heights in the canopy, and evaluate potential interactions with ambient temperature fluctuations. The inner fringing FD sensor can be easily constructed at low cost, suggesting the potential for routine measurement of StWC in diverse woody plants. more...
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- 2018
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13. Influence of ultrasonic vibration on the plasticity of metals during compression process
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Qing-Hua Qin, Haiyang Zhou, and Hongzhi Cui
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010302 applied physics ,Materials science ,Acoustics ,Metals and Alloys ,chemistry.chemical_element ,02 engineering and technology ,Flow stress ,Plasticity ,021001 nanoscience & nanotechnology ,01 natural sciences ,Industrial and Manufacturing Engineering ,Computer Science Applications ,Vibration ,chemistry ,Aluminium ,Modeling and Simulation ,0103 physical sciences ,Ceramics and Composites ,Ultrasonic sensor ,Deformation (engineering) ,0210 nano-technology ,Softening ,Electron backscatter diffraction - Abstract
In this study, the influence of ultrasonic vibration on the plasticity of lightweight metals (aluminium and titanium) was investigated by means of ultrasonic assisted compression (UAC) experiments. The experiments were carried out based on the newly designed ultrasonic horns and transducers which can generate a series of vibration frequencies (20, 30 and 40 kHz) and adjustable vibration amplitudes (4.06–10.37 μm). It is found that, the ultrasonic vibration can reduce flow stress during UAC process for both aluminium and titanium, a phenomenon referred as ultrasonic softening effect. Different vibration amplitude and frequencies were specifically altered for observing the ultrasonic softening effect. The result is: in the range from 20 to 40 kHz the ultrasonic softening effect can be enhanced by increasing the vibration amplitude; however, increasing vibration frequency will decrease the ultrasonic softening effect, which is different from the previous acceptance stating that the vibration frequency (from 18 kHz to 80 kHz) has no influence on the ultrasonic softening effect. Apart from the ultrasonic softening effect, it is also found that the ultrasonic vibration can lead to residual hardening effect to aluminium and residual softening effect to the titanium. The influence of experiment parameters to the ultrasonic softening and residual effect during the UAC were assessed quantitatively and individually. These parameters include vibration frequency and amplitude, vibration duration as well as the sample size. Based on the UAC test within the elastic deformation stage, the mechanism of ultrasonic softening effect was explained from the occurrence of the unload phenomenon caused by ultrasonic vibration induced localized deformation. To validate the proposed mechanism, nanoindentation and electron backscatter diffraction (EBSD) test were carried out. According to the test result, ultrasonic vibration can induce plastic deformation and refine the grains for both aluminium and titanium sample. And for aluminium sample, comparing with the grains in the sample centre, the grains in the sample up boarder area are more sensitive to the ultrasonic vibration in terms of grain refinement, while for the titanium it is on the contrary. more...
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- 2018
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14. Interfacial adhesion mechanisms of ultra-highly filled wood fiber/polyethylene composites using maleic anhydride grafted polyethylene as a compatibilizer
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Junjie Xu, Rongxian Ou, Wenjuan Li, Wei Tang, Qingwen Wang, Haiyang Zhou, and Xiaolong Hao
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Polymer-matrix composites (PMCs) ,Absorption of water ,Materials science ,Mechanical Engineering ,Maleic anhydride ,Interface ,Polyethylene ,chemistry.chemical_compound ,Flexural strength ,chemistry ,Creep ,Fibre/matrix bond ,Mechanics of Materials ,Ultimate tensile strength ,TA401-492 ,General Materials Science ,Fiber ,Natural fibers ,Composite material ,Fourier transform infrared spectroscopy ,Materials of engineering and construction. Mechanics of materials - Abstract
To investigate whether the esterification reaction was the dominant factor that improved the interface compatibility of wood-plastic composites and accordingly their performances, ultra-highly filled wood fiber (WF)/polyethylene composites (UH-WPCs) was fabricated using maleic anhydride grafted polyethylene (MAPE) as compatibilizer or matrix with WF content of 60–85 wt%. The FTIR and TGA results confirm the absolute content of MAPE grafted on WF was 4.5% and 0.9% for the UH-WPCs with 80 wt% WF using MAPE as matrix and compatibilizer, respectively. The UH-WPCs using MAPE as matrix or compatibilizer exhibited considerable higher mechanical properties, better creep resistance, and lower water absorption compared to the uncompatibilized ones. Compared with the uncompatibilized composites with 80 wt% WF, the tensile and flexural strengths were increased by 187% and 186% for using MAPE as matrix, and 224% and 189% for using MAPE as compatibilizer, respectively. These results reveal that the mechanical properties of the UH-WPCs with MAPE were not positively correlated with the absolute content of MAPE grafted on WF. The above findings confirmed that the esterification was not the key determinant for interfacial adhesion mechanisms using MAPE as compatibilizer in UH-WPCs, and some other more important factors may exist. more...
- Published
- 2021
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15. Mechanical properties, morphology, and creep resistance of ultra-highly filled bamboo fiber/polypropylene composites: Effects of filler content and melt flow index of polypropylene
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Qingwen Wang, Lei Chen, Rongxian Ou, Junjie Xu, Chuigen Guo, Wei Tang, Xiaolong Hao, and Haiyang Zhou
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Polypropylene ,Materials science ,Flexural modulus ,Izod impact strength test ,Young's modulus ,Building and Construction ,symbols.namesake ,chemistry.chemical_compound ,chemistry ,Flexural strength ,Creep ,Ultimate tensile strength ,symbols ,General Materials Science ,Composite material ,Civil and Structural Engineering ,Melt flow index - Abstract
Simultaneous realization of high filler fraction and excellent comprehensive properties remains a great challenge for extruded wood plastic composites (WPCs). Herein, ultra-highly filled bamboo fiber/polypropylene composites (UH-BPCs) with total filler content varying from 75 wt% to 90 wt% were fabricated via profile extrusion. Six kinds of polypropylene (PP) with melt flow indices (MFIs) ranging from 0.165 to 24 g (10 min)−1 were selected as the matrix. The tensile, flexural, impact strengths and dimensional stability of the UH-BPCs decreased with increasing filler content. However, a relatively high filler content (no more than 85 wt%) could improve the modulus and creep resistance of UH-BPCs. At 85 wt% filler content, the UH-BPCs with PP of moderate MFI exhibited the best mechanical properties with a tensile strength, tensile modulus, flexural strength, flexural modulus, and unnotched impact strength of 22.39 MPa, 6.05 GPa, 39.86 MPa, 7.19 GPa, and 4.22 kJ m−2, respectively. The UH-BPCs with low MFI PP presented better dimensional stability and creep resistance, especially at high temperatures. This work can provide an important reference to prepare ultra-highly filled WPCs with high performance via profile extrusion. more...
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- 2021
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16. Omnidirectional photonic bandgap in one-dimensional photonic crystals containing hyperbolic metamaterials
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Haiyang Zhou, Guiqiang Du, Xiachen Zhou, Fen Liu, Yunpeng Zhao, Junyang Li, Guang Lu, Ailing Wu, Kaiyuan Zhang, and Chao Diao
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Nanostructure ,Materials science ,Scanning electron microscope ,business.industry ,Physics::Optics ,Dielectric ,Edge (geometry) ,Polarization (waves) ,Atomic and Molecular Physics, and Optics ,Optics ,Photonics ,business ,Omnidirectional antenna ,Photonic crystal - Abstract
We theoretically and experimentally investigate the angle-dependent omnidirectional photonic bandgap (PBG) in one-dimensional photonic crystals (PCs) comprising hyperbolic metamaterials (HMMs) for TM polarization, which is different from blue-shifted PBG in conventional all-dielectric photonic crystals. The frequency range of PBG increases when the incident angles increase, owing to the red-shift and blue-shift of the long-wavelength and short-wavelength band edges, respectively. The red-shifted band edge originates from the phase-variation compensation mechanism between the HMMs and dielectric material. The experimental values are in good agreement with the simulation results. These nanostructures are ideal for fabricating photonic devices such as omnidirectional reflectors. more...
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- 2021
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17. The reinforcement efficacy of nano- and microscale silica for extruded wood flour/HDPE composites: the effects of dispersion patterns and interfacial modification
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Wang Xiaoyu, Qingwen Wang, Haiyang Zhou, Xiaolong Hao, Haigang Wang, Tian Liu, and Yanjun Xie
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Materials science ,Silica fume ,Mechanical Engineering ,Wood flour ,02 engineering and technology ,Polyethylene ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,Creep ,chemistry ,Mechanics of Materials ,Compounding ,General Materials Science ,Particle size ,High-density polyethylene ,Composite material ,0210 nano-technology ,Dispersion (chemistry) - Abstract
The reinforcement efficacy of nano-silica particles for wood/plastic composites (WPCs) has been inconsistent in previous research. Accordingly, this systematic study was conducted to verify the reinforcement feasibility using silica particles. Micro- and nano-silica particles were incorporated into high-density polyethylene (HDPE) via direct compounding (dry dispersion) or by mixing in a solution (wet dispersion), to determine the effects of dispersion and particle size on the reinforcement efficacy of the resulting wood/HDPE composites. Compared with non-filled WPCs, dry dispersion reduced the WPCs’ mechanical strength for microsilica (> 30%), but increased it for nano-silica ( more...
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- 2017
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18. A comparative study of mechanical and microstructural characteristics of aluminium and titanium undergoing ultrasonic assisted compression testing
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Yaogen Shen, Hongzhi Cui, Qing-Hua Qin, Haiyang Zhou, and Hui Wang
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010302 applied physics ,Materials science ,Mechanical Engineering ,Metallurgy ,chemistry.chemical_element ,02 engineering and technology ,respiratory system ,Strain hardening exponent ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,chemistry ,Mechanics of Materials ,Aluminium ,0103 physical sciences ,Hardening (metallurgy) ,Dynamic recrystallization ,General Materials Science ,Ultrasonic sensor ,0210 nano-technology ,Softening ,Titanium ,Electron backscatter diffraction - Abstract
The mechanism of ultrasonic softening effect has been widely investigated and used in the metal material processing area. Deficiency discussion, however, has been focused on the residual effect of ultrasonic vibration on the plasticity of metals only. In this study, ultrasonic vibration assisted compression (UAC) experiments were carried out using commercially pure aluminium and titanium samples. Despite the similar ultrasonic softening effect, different ultrasonic residual effects were observed in the aluminium and titanium samples. Aluminium exhibited a residual hardening phenomenon, whereas in titanium the initial residual hardening effect transferred to a residual softening effect with an increase in amplitude of the applied ultrasonic vibration. Electron backscatter diffraction (EBSD) characterizations revealed that substructure multiplication, texture evolution and dynamic recrystallization caused by the ultrasonic vibration are the main causes of the residual hardening effect of aluminium. The boundary strengthen mechanism based Hall–Petch relationship was used to explain the mechanism and to predict the influence of the ultrasonic residual effect for aluminium. For the titanium, it was found that the ultrasonic vibration reduced the density of deformation twinning in the specimen, and the evolution of residual effect was analysed from the aspects of grain refinement, deformation twinning induced strain hardening. By quantitative study, the main reason for the residual hardening effect of UAC aluminium sample is identified to be the ultrasonic vibration induced grain refinement, while for the titanium, the weakened strain hardening effect induced by deformation twinning should be the main factor accounting for the residual softening of titanium. Also the ultrasonic vibration could have a similar influence as that of the thermal treatment to the titanium sample, resulting in the yield point elongation (YPE) phenomenon. more...
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- 2017
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19. A large-grain-size thick-film polycrystalline diamond detector for x-ray detection
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Changjun Qiu, Ping Xu, Haiyang Zhou, and Yi Yu
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Materials science ,business.industry ,Detector ,X-ray ,X-ray detector ,Optoelectronics ,Condensed Matter Physics ,business ,Polycrystalline diamond ,Grain size - Published
- 2020
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20. Effects of fiber geometry and orientation distribution on the anisotropy of mechanical properties, creep behavior, and thermal expansion of natural fiber/HDPE composites
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Qiong Guo, Rongxian Ou, Haiyang Zhou, Lichao Sun, Xiaolong Hao, Yi Xin, Qingwen Wang, Binshan Mu, and Lei Chen
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Materials science ,Mechanical Engineering ,02 engineering and technology ,Polyethylene ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Industrial and Manufacturing Engineering ,Thermal expansion ,0104 chemical sciences ,chemistry.chemical_compound ,Flexural strength ,Creep ,chemistry ,Mechanics of Materials ,Ceramics and Composites ,High-density polyethylene ,Fiber ,Composite material ,0210 nano-technology ,Anisotropy ,Natural fiber - Abstract
Natural fiber/high-density polyethylene (HDPE) composites (NFPCs) were fabricated via extrusion using three types of natural fibers from poplar wood (PW), radiata pine (RP), and rice husk (RH), respectively. The specimens were cut from the extruded samples at various off-axis angles (from 0° to 90°). The effect of fiber geometry and orientation distribution on the mechanical properties, creep behavior, and thermal expansion of the NFPCs was investigated. The natural fibers in the composites showed a preferential orientation along the extrusion direction, as evidenced by the optics micrographs. The flexural properties and impact strength of the NFPCs were the highest at zero angle and decreased considerably with increasing orientation angle, which was further validated by the finite element analysis. At zero angle, the PW/HDPE composites had the highest flexural and impact strength and the smallest creep strain and thermal expansion, but a small difference in mechanical properties was observed at 90° among the NFPCs. The significant anisotropy of properties at various angles of the PW/HDPE composites was due to the high aspect ratio (L/D) of poplar wood fiber. These results indicate that high fiber L/D and orientation distribution had a beneficial effect on the properties of NFPCs. more...
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- 2020
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21. Conductive and fire-retardant wood/polyethylene composites based on a continuous honeycomb-like nanoscale carbon black network
- Author
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Qingwen Wang, Yanjun Xie, Fengqiang Wang, Haiyang Zhou, Zefang Xiao, Xiaolong Hao, Yongming Song, and Yonggui Wang
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Smoke ,Materials science ,0211 other engineering and technologies ,020101 civil engineering ,02 engineering and technology ,Building and Construction ,Carbon black ,Polyethylene ,Conductivity ,0201 civil engineering ,chemistry.chemical_compound ,chemistry ,EMI ,021105 building & construction ,General Materials Science ,Composite material ,Electrical conductor ,Nanoscopic scale ,Civil and Structural Engineering ,Fire retardant - Abstract
This study prepares multi-functional wood/polyethylene composites (WPCs) by addition of a small amount of nanoscale conductive carbon black (CCB), leading to honeycomb-distributed WPC (WPCH-CCB). The conductivity, electromagnetic interference shielding (EMI SE), and flame-retardancy of WPCH-CCB were comparatively studied with the uniformly-distributed WPC (WPCU-CCB) prepared through a conventional melt-blending process. The conductivity and EMI SE of the WPCH-CCB reached up to 1.5 × 10−2 S·cm−1 and 20.2 dB at 3 wt% CCB content, respectively. In comparison, the conductivity and EMI SE of the WPCU-CCB only had 8.3 × 10−14 S·cm−1 and 5.0 dB. Moreover, the cone calorimetric analysis revealed that the WPCH-CCB had lower smoke production and heat release than the WPCU-CCB. more...
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- 2020
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22. Fast radial scanning probe system on KTX
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Tijian DENG, Tao LAN, Mingsheng TAN, Junfeng ZHU, Jie WU, Hangqi XU, Chen CHEN, Yolbarsop ADIL, Sen ZHANG, Jiaren WU, Yiming ZU, Wenzhe MAO, Hong LI, Jinlin XIE, Ahdi LIU, Zixi LIU, Zhengwei WU, Hai WANG, Xiaohui WEN, Haiyang ZHOU, Zian WEI, Chijin XIAO, Weixing DING, Ge ZHUANG, and Wandong LIU more...
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Electron density ,Optics ,Materials science ,business.industry ,Resolution (electron density) ,Plasma ,Condensed Matter Physics ,business ,Image resolution - Published
- 2020
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23. An improved sensor for precision detection of in situ stem water content using a frequency domain fringing capacitor
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Wenyi Sheng, Yurui Sun, Peter Schulze Lammers, Qiang Cheng, Henrik Schumann, Melvin T. Tyree, Xuzhang Xue, and Haiyang Zhou
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Materials science ,Plant Stems ,Physiology ,business.industry ,Frequency domain sensor ,Water ,Relative permittivity ,Plant Science ,Electric Capacitance ,Signal ,Droughts ,Optics ,Species Specificity ,Xylem ,Frequency domain ,Gravimetric analysis ,Time domain ,business ,Reflectometry ,Water content - Abstract
One role of stems is that of water storage. The water content of stems increases and decreases as xylem water potential increases and decreases, respectively. Hence, a nondestructive method to measure stem water content (StWC) = (volume of water) : (volume of stem), could be useful in monitoring the drought stress status of plants. We introduce a frequency domain inner fringing capacitor-sensor for measuring StWC which operates at 100 MHz frequency. The capacitor-sensor consists of two wave guides (5-mm-wide braided metal) that snugly fit around the surface of a stem with a spacing of 4-5 mm between guides. Laboratory measurements on analog stems reveals that the DC signal output responds linearly to the relative dielectric constant of the analog stem, is most sensitive to water content between the waveguides to a depth of c. 3 mm from the stem surface, and calibrations based on the gravimetric water loss of excised stems of plants revealed a resolution in StWC of < ± 0.001 v/ v. The sensor performed very well on whole plants with a 100-fold increased resolution compared with previous frequency domain and time domain reflectometry methods and, hence, may be very useful for future research requiring nondestructive measurements of whole plants. more...
- Published
- 2014
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24. In situ observation of thermal and hydraulic responses of sunflower stem to cold water irrigation using embedded thermocouples
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Yurui Sun, Lutz Damerow, Qiang Cheng, Haiyang Zhou, Tomas Norton, Henrik Schumann, B. Wen, and P. Schulze Lammers
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Irrigation ,Materials science ,fungi ,food and beverages ,Xylem ,Forestry ,Horticulture ,Herbaceous plant ,Grafting ,Sunflower ,Computer Science Applications ,Agronomy ,Thermocouple ,TRACER ,Helianthus annuus ,Agronomy and Crop Science - Abstract
Implant a thermocouple sensor array between two sunflower stems grated.Snapshot of the instantaneous thermal responses of the plant to irrigation.Snapshot of the instantaneous hydraulic responses of the plant to irrigation.A comparison between root- and stem-hydraulic conductibility. Obtaining in situ observation of plant water relations has long been one of the goals of plant approach. For contributing to this, a plant grafting technique was utilized in the current work to implant a tiny thermocouple sensor array (1mm diameter, T-type) between the paired stems (7 and 8mm in diameter) of sunflower samples (Helianthus annuus L.) grown in a single pot. The experiment was conducted when these two stems physically grew together. Snapshots of the thermal and hydraulic responses were then observed by irrigating the three paired sunflower samples with cold-water. Because the plant samples had no thermal regulating function but had water regulating function, the recorded time series of the stem temperatures was found to be a useful tracer for the sap flow passing through the xylem conduits of the stem. By following this tracer we observed that the velocity of the sap flow through the root was slower than that through the stem for the sunflower samples. The results presented in this application note demonstrated the possibility of implanting tiny passive sensors into herbaceous plants for in situ observation of plant physiological signals. more...
- Published
- 2014
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25. Experimental and numerical investigation of electromagnetic bulging of titanium alloy Ti-6Al-4V at room temperature
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Liang Huang, Li Qiu, Jianjun Li, Li Fenqiang, Jianhua Mo, and Haiyang Zhou
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Impact pressure ,Materials science ,Computer simulation ,business.industry ,Mechanical Engineering ,Titanium alloy ,chemistry.chemical_element ,Structural engineering ,Mechanics ,Deformation (meteorology) ,Strain rate ,Copper ,Industrial and Manufacturing Engineering ,chemistry ,Ti 6al 4v ,Impact ,business - Abstract
In this article, electromagnetic bulging of high-strength, low-conductivity Ti-6Al-4V using a T3 copper driver plate at room temperature was described. The investigation was conducted employing numerical simulation method. Numerical prediction of the deformation contour and thickness distribution were closely correlated with the experimental results. The distribution of electromagnetic force on the driver plate and impact force between the driver plate and the workpiece varying with time was obtained. Besides, deformation velocity distribution and strain rate on the workpiece were determined by analyzing the deformation process. Energy efficiency of the process was determined to be 1.34%. Distribution of total electromagnetic force over time is characteristic of a sine-squared attenuation function. Velocity of the second impact near the center zone is 229.36 m/s with a corresponding impact pressure of 3.42 GPa. The results of this investigation are significant in the design of an improved process of electromagnetic forming of Ti-6Al-4V and other low-conductivity metals. more...
- Published
- 2014
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26. Formability of Ti–6Al–4V titanium alloy sheet in magnetic pulse bulging
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Li Fenqiang, Jianhua Mo, Li Jianjun, Liang Huang, and Haiyang Zhou
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Shear (sheet metal) ,Materials science ,Metallurgy ,Fracture (geology) ,Titanium alloy ,Forming processes ,Formability ,Fractography ,Strain rate ,Composite material ,Electromagnetic forming - Abstract
In order to investigate the formability of Ti–6Al–4V titanium alloy sheet in high speed forming process, electromagnetic forming (EMF) namely magnetic pulse forming with an Al driver sheet is performed experimentally. Formability under EMF is compared with that in quasi static condition. Fracture analysis for the titanium alloy Ti–6Al–4V is then carried out to study the fracture mechanism and material response. Results indicate that the formability undergoing EMF process with a driver sheet is increased beyond that exhibited in quasi-static tests. In electromagnetic free bulging, the forming limit of Ti–6Al–4V increases by 24.37%, which is more optimistic than AA5052-O. Fractography analysis using SEM determines that the Ti–6Al–4V titanium alloy sheet fails in a combination of ductile fracture and shear fracture when subjected to the electromagnetic bulging process while only ductile fracture develops in quasi-static condition. more...
- Published
- 2013
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27. Study on the driver plate for electromagnetic forming of titanium alloy Ti-6Al-4V
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Liang Huang, Li Fenqiang, Jianhua Mo, Haiyang Zhou, and Jianjun Li
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Materials science ,Computer simulation ,Mechanical Engineering ,Alloy ,Process (computing) ,Mechanical engineering ,chemistry.chemical_element ,Titanium alloy ,engineering.material ,Deformation (meteorology) ,Industrial and Manufacturing Engineering ,Computer Science Applications ,Electromagnetic forming ,chemistry ,Control and Systems Engineering ,Aluminium ,visual_art ,engineering ,visual_art.visual_art_medium ,Sheet metal ,Software - Abstract
In order to improve energy efficiency, a driver plate made from high-conductivity material is normally used in the electromagnetic forming process of high-strength but low-conductivity sheet metal. The choice of driver plate significantly influences final deformation of the workpiece. In this paper, the electromagnetic free bulging process of Ti-6Al-4V titanium alloy sheet, widely used in aerospace, was studied by both experimental means and numerical simulation. The forming efficiency and quality of the workpiece under different types of driver plates were investigated in detail. The results show that by using high-conductivity and easily deformed materials such as aluminum alloy, with a skin depth in thickness, high efficiency and uniform deformation can be achieved. The results of this study can provide guidance on the choice of process parameters such as the material and thickness of a driver plate. more...
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- 2013
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28. 3D Numerical simulation method of electromagnetic forming for low conductive metals with a driver
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Li Fenqiang, Jianhua Mo, Haiyang Zhou, and Yang Fang
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Electromagnetic field ,Materials science ,Mechanical Engineering ,Mechanical engineering ,Titanium alloy ,Forming processes ,Deformation (meteorology) ,Blank ,Industrial and Manufacturing Engineering ,Computer Science Applications ,Electromagnetic forming ,Condensed Matter::Materials Science ,Control and Systems Engineering ,Formability ,Image warping ,Software - Abstract
Electromagnetic forming (EMF) process is a high-speed forming process which can inhibit warping, reduce springback, and improve the formability of material at room temperature. In general, the electromagnetic forming process is applied to high-conductive metals such as copper, aluminum, and their alloys. In order to solve the problem of the low formability of titanium alloy, the electromagnetic forming process can be applied to form titanium alloy. The effects on the forming properties of titanium and other low-conductive metals must be studied before the EMF process is used. To that end, this paper presents a tool: a 3D numerical simulation method of electromagnetic forming with a driver. First, the electromagnetic field distribution and electromagnetic forces are calculated using the ANSYS/EMAG software. The resulting data are then imported to ABAQUS/Explicit software to carry out mechanical analysis. Although the electromagnetic field calculation does not take the deformation of the blank into account, the results accurately reflect the law of the deformation. This method is especially suitable for cases involving small deformations, such as tube compression and embossing. The calculation can also be used to simulate the impact forming process between the driver and the blank. more...
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- 2012
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29. Reinforcement of wood flour/HDPE composite with a copolyester of p -hydroxy benzoic acid and 2-hydroxy-6-naphthoic acid
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Yanjun Xie, Xiaolong Hao, Haiyang Zhou, Yongming Song, Qingwen Wang, and Haigang Wang
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Materials science ,Polymers and Plastics ,Composite number ,Wood flour ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Copolyester ,0104 chemical sciences ,Surfaces, Coatings and Films ,chemistry.chemical_compound ,chemistry ,Materials Chemistry ,High-density polyethylene ,0210 nano-technology ,Reinforcement ,Naphthoic acid ,Nuclear chemistry ,Benzoic acid - Published
- 2018
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30. Investigation into the antibacterial property of carbon films
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Akihisa Ogino, Masaaki Nagatsu, Haiyang Zhou, and Lei Xu
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Materials science ,Mechanical Engineering ,Analytical chemistry ,chemistry.chemical_element ,General Chemistry ,engineering.material ,Electronic, Optical and Magnetic Materials ,Amorphous solid ,symbols.namesake ,Film coating ,Carbon film ,chemistry ,Coating ,Chemical engineering ,Plasma-enhanced chemical vapor deposition ,Materials Chemistry ,symbols ,engineering ,Electrical and Electronic Engineering ,Thin film ,Raman spectroscopy ,Carbon - Abstract
Here we reported the antibacterial characteristics of carbon film and the effect of film composition on its antibacterial performance. Two kinds of carbon films, amorphous hydrogenated carbon film and hydrogen-free carbon film deposited on medical stainless steel using microwave plasma were characterized using Raman Spectra, FT-IR (Fourier transform-infrared spectroscopy), AFM (atomic force microscopy) methods and investigated on their antibacterial property. By the colony-counting method, it was found that the H-free carbon film coating and a-C:H film coating reduced the numbers of E. coli colonies down to about 15% and 33% of those in the original SUS substrate, respectively. The present results suggested that the antibacterial property was strongly related with the chemical inertness of carbon film. more...
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- 2008
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31. Thickness measurement of low reflectance optical thin film with transparent substrate
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Feihong Yu, Qianshun Liu, Haiyang Zhou, and Guo Xia
- Subjects
Optical film ,Optics ,Materials science ,Opacity ,Stack (abstract data type) ,business.industry ,Optoelectronics ,Substrate (printing) ,Thin film ,business ,Reflectivity ,Optical thin film - Abstract
Because of the substrate back reflectance phenomena, the reflectance of optical thin film stack on a transparent substrate is totally different from that of on an opaque substrate. In this paper, a method for the measurement of low reflectance optical film thickness that has substrate back reflectance is proposed for the first time. Through the analysis of the actual substrate back reflectance, a compensation model is introduced to reduce the influence of substrate back reflectance. The experimental results show good fitting precision and proves that this model can be used directly for the measurement of the optical film thickness with substrate back reflectance, and no extra process is needed. more...
- Published
- 2015
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32. Numerical Investigations of Flow Separation Control for a Low Pressure Turbine Blade Using Steady and Pulsed Vortex Generator Jets
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Xiaomin Liu and Haiyang Zhou
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Materials science ,Turbine blade ,business.industry ,Turbulence ,Mass flow ,Reynolds number ,Mechanics ,Vortex generator ,Turbine ,Vortex ,law.invention ,symbols.namesake ,Flow separation ,law ,symbols ,Aerospace engineering ,business - Abstract
This paper investigated numerically the application of Vortex Generator Jets (VGJs) to control flow separation on the suction side of a low pressure turbine blade. Firstly, numerical simulations of flow separation for a LPT blade, which based on Menter’s SST k-ω turbulence model coupled with Langtry-Menter transition model, were performed for different Reynolds numbers Re∼100,000, 75,000, 50,000 and 25,000, for three freestream turbulence intensity (FSTI) of 0.08%, 2.35% and 6.0%. The pressure distributions around the turbine blade and streamline plots showing the flow separation were presented in this paper. Good agreement of the numerical and experimental results also showed the validity of the numerical scheme for simulating the flow separation occurring on a low pressure turbine blade. And then, steady Vortex Generator Jets (steady VGJs) having pitch angle of 30°, skew angle of 90°, blowing ratio of 2.0 were used to control the flow separation in the suction side of the low pressure turbine blade. Although steady VGJs have been illustrated to be extremely robust at suppressing low Reynolds number separation, the practical application of VGJs in the low pressure turbine engine is in the pulsed mode. The injection mass flow requirements of pulsed Vortex Generator Jets (pulsed VGJs) can be reduced drastically when similar flow control effect is obtained using steady VGJs. For pulsed VGJs, the pulse frequency has been found to be an important control parameter for the flow separation control. In this paper, cases with the duty cycle of 0.5 were studied for the pulse frequency ranging from 2.5Hz to 10Hz at Re = 25,000 and freestream turbulence level of 0.08%. The numerical results showed that pulsed VGJs can effectively reduce and even eliminate the flow separation on the blade suction surface while there is an optimal pulse frequency. The flow control mechanism of VGJs on LPT blade was also revealed.Copyright © 2010 by ASME more...
- Published
- 2010
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33. Analytical Studies on Mode III Fracture in Flexoelectric Solids.
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Xinpeng Tian, Mengkang Xu, Haiyang Zhou, Qian Deng, Qun Li, Sladek, Jan, and Sladek, Vladimir
- Subjects
- *
FRACTURE mechanics , *STRAINS & stresses (Mechanics) , *MATERIALS science , *ELECTROMECHANICAL effects , *STRESS concentration - Abstract
Due to the stress concentration near crack tips, strong flexoelectric effect would be observed there, which might lead to new applications of flexoelectricity in material science and devices. However, different from the flexoelectric effect in cantilever beams or truncated pyramids, at the crack tip, multiple components of strain gradients with nonuniform distribution contribute to the flexoelectric effect, which makes the problem extremely complex. In this paper, with the consideration of both direct and converse flexoelectricity, the electromechanical coupling effect around the tip of a Mode III crack is studied analytically. Based on the Williams' expansion method, the displacement field, polarization field, strain gradient field along with the actual physical stresses field are solved. A path-independent J-integral for Mode III cracks in flexoelectric solids is presented. Our results indicate that the existence of flexoelectricity leads to a decrease of both the J-integral and the out-of-plane displacement in Mode III cracks, which means that the flexoelectric effect around the tip of Mode III cracks enhances the local strength of materials. [ABSTRACT FROM AUTHOR] more...
- Published
- 2022
- Full Text
- View/download PDF
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