المؤلفون: Qijiang Ma, Qiu Xia, Qi Wang, Cui Xiao, Shahzad Iqbal, Asad Ali, Guorui Gao, Ibra Fall

المصدر: AIP Advances, Vol 14, Iss 6, Pp 065224-065224-11 (2024)

مصطلحات موضوعية: Physics, QC1-999

الوصف: This study examines the effects of water vapor on the performance and stability of a Roots-type hydrogen circulation pump. The accuracy of the numerical model was initially confirmed using air as the experimental medium, and subsequent simulations were conducted with pure hydrogen or mixed media containing water vapor. Analysis of pressure and velocity distribution within the pump revealed that water vapor does not significantly impact these factors. However, the interaction between hydrogen and water vapor results in the formation of larger hydrogen clusters, reducing internal leakage flow and leading to a slight increase in inlet and outlet flow rates. The presence of water vapor in the suction chamber increases turbulence energy in the root region of the rotor, influencing flow patterns and creating multi-scale vortex structures. In the exhaust chamber, the turbulence energy is lower and there are fewer vortices, but high-energy vortices may occur at the connection to the exhaust pipe, affecting the outlet flow rate.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2158-3226Test

الوصول الحر: https://doaj.org/article/132eb1b0159d482aba2cc9e86890c11eTest

المؤلفون: Gao, Xue-ying¹ (AUTHOR), Cui, Xiao-bin¹ (AUTHOR), Zhang, Yong¹ (AUTHOR), Zhu, Jie-jun¹ (AUTHOR) zhujj@njtech.edu.cn, Huang, Cheng-ping¹ (AUTHOR) cphuang@njtech.edu.cn

المصدر: AIP Advances. Mar2023, Vol. 13 Issue 3, p1-6. 6p.

مصطلحات موضوعية: *SOUND waves, *ACOUSTIC localization, *ACOUSTIC intensity, *ANDERSON localization, *ENERGY harvesting

مستخلص: Fresnel zone plates (FZP) with quasi-planar structure and ultrathin thickness are capable of focusing light or acoustic waves efficiently. In this paper, we employ the FZP to manipulate the wave fields and suggest two acoustic functionalities. On one hand, by placing the moving coil-type microphone near the focal point of the FZP, enhanced acoustoelectric conversion is realized. The measured output voltage and power attained are 18.5 mV and 130 nW, respectively, which are 5.1 and 27.3 times that obtained without the FZP. On the other hand, by setting a tapered tube near the focal point of the FZP, deep-subwavelength and efficient localization of acoustic waves at the tube end (the mode size is around λ/20) are suggested theoretically. The cascaded focusing scheme leads to an enhancement of the acoustic intensity of the hotspot by more than 8700 times. The results are useful for realizing acoustic energy harvesting, strong mode localization, and acoustic-field enhancement. [ABSTRACT FROM AUTHOR]

المؤلفون: Zhang, Xianfeng, Xu, Kuilong, Yang, Xiao, Cui, Xiao, Bian, Bingchuan, Zhang, Xinyao, Hou, Shizhong, Chen, Jieming

المصدر: AIP Advances; Jul2021, Vol. 11 Issue 7, p1-9, 9p

مصطلحات موضوعية: METALLIC glasses, MATERIAL plasticity, TRANSMISSION electron microscopes, LOW temperatures

مستخلص: A series of Zr50.75Cu35.75Al8.5Ag5 bulk metallic glasses (BMGs) were prepared by controlling the cooling rate and over-heating temperature. The plastic deformation behavior of the BMGs was examined. The plasticity was enhanced when the BMG was prepared at a high cooling rate and low over-heating temperature. The plasticity of the Zr-based BMGs prepared under different casting conditions was discussed based on the amount of free volume. The structural heterogeneity of the BMGs prepared with different over-heating temperatures was examined using a high-resolution transmission electron microscope and mapped by using an energy dispersive x-ray spectroscope. The results showed that a low over-heating temperature could increase the degree of heterogeneity, but an extremely low over-heating temperature could lead to nanocrystallization. The difference in the heterogeneous structures caused the distinct plastic performance of the Zr50.75Cu35.75Al8.5Ag5 BMGs prepared with different over-heating temperatures. [ABSTRACT FROM AUTHOR]

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المؤلفون: Bian, Bingchuan¹ (AUTHOR), Cui, Xiao¹ (AUTHOR) xcui@live.com, Li, Jinjing¹ (AUTHOR)

المصدر: AIP Advances. Jan2021, Vol. 11 Issue 1, p1-6. 6p.

مصطلحات موضوعية: *METALLIC glasses, *THERMAL stability, *GLASS transition temperature, *MATERIAL plasticity, *DIFFERENTIAL scanning calorimetry, *INTERNAL friction

مستخلص: In this work, the long-term thermal stability, dynamic relaxation behavior, and mechanical performance of (La60Ce40)60Al15Co25 bulk metallic glass (BMG) were studied using differential scanning calorimetry, internal friction measurement, and compression testing, respectively. The long-term stability of the LaCe-based BMG was realized by constructing a continuous heating transformation diagram on the basis of the kinetic characteristics of the crystallization behavior. The internal friction analysis of the LaCe-based BMG showed the emergence of prominent slow β relaxation before the glass transition temperature. The β relaxation had a close relationship with the heterogeneous distribution and the good mobility of the constituting elements. The compression testing results in different temperature ranges near and far from the activation temperature of the β relaxation showed that the plastic deformation could proceed continuously as the deformation temperature reached the activation temperature of the β relaxation. [ABSTRACT FROM AUTHOR]

المؤلفون: Liang, Deshan¹ (AUTHOR), Cui, Xiao¹ (AUTHOR), Ma, Xingqiao¹ (AUTHOR) xqma@sas.ustb.edu.cn, Shi, Xiaoming² (AUTHOR), Wang, Jing² (AUTHOR), Jafri, Hasnain Mehdi² (AUTHOR), Wang, Junsheng² (AUTHOR), Wang, Zhengzhi³ (AUTHOR), Huang, Houbing² (AUTHOR) hbhuang@bit.edu.cn

المصدر: AIP Advances. Oct2020, Vol. 10 Issue 10, p1-6. 6p.

مصطلحات موضوعية: *CONCENTRATION gradient, *MAGNETIC particles, *PARTICLE motion, *NANOCOMPOSITE materials, *BIOMIMETIC materials, *NANOPARTICLE size, *MAGNETIC fields

مستخلص: Magnetically actuated functional gradient nanocomposites have widely been used for ultra-durable biomimetic interfaces and surfaces. However, the mechanical and thermal mismatches in integrated systems containing dissimilar materials or structures usually cause failures. By modulating the concentration of magnetic particles, a suitable mechanical gradient morphology can be generated to match different integrated systems. In this work, a new model is developed to describe magnetic particle motion under the magnetic field. Hybrid nano-reinforcements with two different magnetic particle sizes and concentrations were employed to optimize the magnetic particle concentration gradient. It was observed that the diversification of concentration distribution can be achieved by tuning the sizes and concentrations of nanoparticles. The present study, therefore, contributes toward the understanding of the transport mechanism of magnetic-field-actuated functional gradient nanocomposites and provides guidance for experiments to design ultra-durable biomimetic interfaces and surfaces. [ABSTRACT FROM AUTHOR]