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Time-resolved radial uniformity of pulse-modulated inductively coupled O_(2)/Ar plasmas

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Chinese Physics B 2021年第6期30卷 401-408页

作者： Wei Liu Chan Xue Fei Gao yong-Xin Liu You-Nian Wang yong-tao zhao School of Optoelectronic Engineering Xi'an Technological UniversityXi'an 710021China School of Science Xi'an Jiaotong UniversityXi'an 710049China School of Aerospace Science and Technology Xidian UniversityXi'an 710126China School of Physics Dalian University of TechnologyDalian 116024China

Time-resolved radial uniformity of pulse-modulated inductively coupled O_(2)/Ar plasma has been investigated by means of a Langmuir probe as well as an optical probe in this paper. The radial uniformity of plasma has been discussed through analyzing the nonuniformity factor β(calculated by the measured n_e, lower β means higher plasma radial uniformity). The results show that during the active-glow period, the radial distribution of ne exhibits an almost flat profile at the beginning phase, but it converts into a parabola-like profile during the steady state. The consequent evolution for β is that when the power is turned on, it declines to a minimum at first, and then it increases to a maximum, after that, it decays until it keeps constant. This phenomenon can be explained by the fact that the ionization gradually becomes stronger at the plasma center and meanwhile the rebuilt electric field(plasma potential and ambipolar potential) will confine the electrons at the plasma center as well. Besides, the mean electron energy( _(on)) at the pulse beginning decreases with the increasing duty cycle. This will postpone the plasma ignition after the power is turned on. This phenomenon has been verified by the emission intensity of Ar(λ = 750.4 nm). During the after-glow period, it is interesting to find that the electrons have a large depletion rate at the plasma center. Consequently, ne forms a hollow distribution in the radial direction at the late stage of after-glow. Therefore, β exhibits a maximum at the same time. This can be attributed to the formation of negative oxygen ion(O^(-)) at the plasma center when the power has been turned off.

关键词： plasma radial uniformity pulse-modulated discharge inductively coupled plasma Langmuir probe

A fitting formula for electron–ion energy partition fraction of 3.54-MeV fusion alpha particles in hot dense deuterium–tritium plasmas

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Chinese Physics B 2021年第1期30卷 345-349页

作者： Yan-Ning Zhang Zhi-Gang Wang yong-tao zhao Bin He School of Science Xi’an Jiaotong UniversityXi’an 710049China Institute of Applied Physics and Computational Mathematics Beijing 100088China

Based on our previous work(*** 25 012704(2018)),a fitting formula is given for electron-ion energy partition fraction of 3.54-MeV fusion alpha particles in deuterium-tritium(DT) plasmas as a function of plasma mass density ρ,electron temperature T_(e),and ion temperature T_(i).The formula can be used in a huge range of the plasma state,where ρ varies between 1.0 g/cc~10.0^(3) g/cc and both T_(e) and T_(i) change from 0.1 keV to 100.0 *** effect for electrons is investigated including the effect of the projectile recoil in the plasmas at T_(e)≥ 50.0 *** partition fraction for T_(e)>T_(i) is found to be close to that for T_(e)=T_(i). The comparisons with other fitting results are made at some plasma densities when T_(e)=T_(i),and the difference is *** fitting result is very close to the calculated one in most cases,which is convenient for the simulation of alpha heating in hot dense DT plasmas for inertial confined fusion.

关键词： inertial confinement fusion deuterium–tritium plasma alpha heating energy loss

Coral reef-like polyanaline nanotubes prepared by a reactive template of manganese oxide for supercapacitor electrode

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Chinese Chemical Letters 2011年第8期22卷 964-968页

作者： Ling Ren Wang Fen Ran yong tao Tan Lei zhao Ling Bin Kong Long Kang State Key Laboratory of Gansu Advanced Non-Ferrous Metal Materials Lanzhou University of Technology Lanzhou 730050 China

Coral reef-like PANI nanotubes composed of nanopaticles were successfully synthesized by a reactive template of manganese *** structure was characterized by using SEM,TEM,and FT-IR,and the supercapacitive behaviors of these nanotubes were investigated with cyclic voltammetry（CV）,and charge-discharge tests,respectively.A maximum specific capacitance of 533 F/g could be achieved in 1mol/L aqueous H_2SO_4 with the potential range of -0.2 to 0.8 V（*** saturated calomel electrode） in a half-cell setup configuration for PANI electrode,suggesting its potential application in the electrode material for electrochemical capacitors.

关键词： Electrochemical capacitors PANI Reactive template Specific capacitance

Gradient maturation experiment on hairs implies taphonomic changes in fossil hairs

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Science China Earth Sciences 2025年第1期68卷 62-73页

作者： Xin LI Yibo ZHOU tao zhao Xingjian HE Yanhong PAN State Key Laboratory for Mineral Deposits Research Center for Critical Earth Material Cycling Centre for Research and Education on Biological Evolution and Environment and Frontiers Science School of Earth Sciences and Engineering Nanjing University Institute of Palaeontology Yunnan Key Laboratory of Earth System Science Yunnan Key Laboratory for PalaeobiologyYunnan University

Mammalian hair, as a key feature related to endothermy, physical protection, and camouflage, has a long geohistorical record that dates back even to the Mesozoic. However, the limited information on the taphonomy of hair hinders the understanding of its evolutionary significance in deep time. To address this, we conducted taphonomic experiments to simulate the transformation process of black hair. The changes in the morphological structure, microscopic characteristics, and chemical composition of hair during the simulated fossilization process were documented by scanning electron microscopy, Fourier transform infrared(FTIR) spectroscopy, and Raman spectroscopy. Our results revealed that damage to the morphology of hair began at a mild temperature(150–175°C), and hair transformed into a fluid-like mass at a relatively high temperature(200°C). In addition, the morphological structure of melanosomes had relatively greater preservation potential than keratins did, and the microscopic features of melanosomes were persistently stable. The Raman and FTIR spectra indicated that the characteristic melanin and keratin peaks changed as the temperature increased. Although the chemical signals were not lost completely, the variations in the characteristic amide bands in the FTIR spectra indicate that the keratins severely degraded at high temperatures(>200°C), whereas the characteristic melanin bands in the Raman spectra suggested that melanin signals were still recognizable, even at high temperatures(>200°C). These results were confirmed by principal component analysis(PCA) and principal component analysis linear discriminant analysis(PCA–LDA). In addition, the Raman signals of all the samples in the simulated experiments were distinguished from the signals of common geological carbonaceous materials(humic acid), which suggested that Raman spectroscopy can be used to detect melanin in fossils.

关键词： Mammalian hair Melanin Keratin Fossilization Experimental taphonomy

Simulations of spin/polarization-resolved laser-plasma interactions in the nonlinear QED regime

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Matter and Radiation at Extremes 2023年第6期8卷 11-29页

作者： Feng Wan Chong Lv Kun Xue Zhen-Ke Dou Qian zhao Mamutjan Ababekri Wen-Qing Wei Zhong-Peng Li yong-tao zhao Jian-Xing Li Ministry of Education Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter Shaanxi Province Key Laboratory of Quantum Information and Quantum Optoelectronic DevicesSchool of PhysicsXi’an Jiaotong UniversityXi’an 710049China Department of Nuclear Physics China Institute of Atomic EnergyP.O.Box 275(7)Beijing 102413China

Strong-field quantum electrodynamics(SF-QED)plays a crucial role in ultraintense laser-matter interactions and demands sophisticated techniques to understand the related physics with new degrees of freedom,including spin angular *** investigate the impact of SF-QED processes,we have introduced spin/polarization-resolved nonlinear Compton scattering,nonlinear Breit-Wheeler,and vacuum birefringence processes into our particle-in-cell(PIC)*** this article,we provide details of the implementation of these SF-QED modules and share known results that demonstrate exact agreement with existing single-particle *** coupling normal PIC simulations with spin/polarization-resolved SF-QED processes,we create a new theoretical platform to study strong-field physics in currently running or planned petawatt or multi-petawatt laser facilities.

关键词： resolved nonlinear details

X-ray emission for Ar^(11+)ions impacting on various targets in the collisions near the Bohr velocity

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Chinese Physics B 2021年第8期30卷 312-316页

作者： Xian-Ming Zhou Jing Wei Rui Cheng Yan-Hong Chen Ce-Xiang Mei Li-Xia Zeng Chang-Hui Liang Yao-Zong Li yong-tao zhao Xiao-An Zhang Ion Beam and Optical Physics Joint Laboratory of Xianyang Normal University and Institute of Modern Physics of CAS Xianyang Normal UniversityXianyang 712000China School of Science Xi'an Jiaotong UniversityXi'an 710049China Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China

X-ray emission from the collisions of 3 MeV Ar^(11+)ions with V,Fe,Co,Ni,Cu,and Zn is *** the x-rays of the target atom and projectile are observed *** x-ray yield is extracted from the original *** inner-shell ionization cross section is estimated by the binary encounter approximation model and compared with the experimental *** remarkable result is that the Ar K-shell x-ray yield is diminished with the target atomic number increasing,which is completely opposite to the theoretical *** is interpreted by the competitive consumption of the energy loss for the ionization of inner-shell electrons between the projectile and target atom.

关键词： ion-atom collision near Bohr velocity x-ray coulomb ionization

Nd L-shell x-ray emission induced by light ions

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Chinese Physics B 2022年第6期31卷 310-315页

作者： Xian-Ming Zhou Jing Wei Rui Cheng Yan-Hong Chen Ce-Xiang Mei Li-Xia Zeng Yu Liu Yan-Ning Zhang Chang-Hui Liang yong-tao zhao Xiao-An Zhang Ion Beam and Optical Physics Joint Laboratory of Xianyang Normal University and Insitite of Modern Physics Chinese Academy of SciencesXianyang Normal UniversityXianyang 712000China School of Science Xi’an Jiaotong UniversityXi’an 710049China Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China

The L-shell x-ray of Nd has been obtained for 300-600 keV He2+ions impacting,and compared with that produced by H+and H2+*** threshold of projectile kinetic energy for L-shell ionization of Nd is crudely verified in the energy region of about 300-400 *** is found that the energy of the distinct L-subshell x-rays has a blue *** relative intensity ratios of Lβ_(1,3,4)and Lβ_(2,15)to Lα_(1,2)x-ray are enlarged compared to the atomic data,and they decrease with the increase of the incident energy,and increase with increasing the effective nuclear charge of the incident *** is interpreted by the multiple ionization of outer-shells induced by light ions.

关键词： light ions ion-atom collision L-shell x-ray multiple ionization

Preparation of FeCoNi medium entropy alloy from Fe^(3+)-Co^(2+)-Ni^(2+)solution system

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 92-101页

作者： Zongyou Cheng Qing zhao Mengjie tao Jijun Du Xingxi Huang Chengjun Liu Key Laboratory for Ecological Metallurgy of Multimetallic Mineral(Ministry of Education) Northeastern UniversityShenyang 110819China School of Metallurgy Northeastern UniversityShenyang 110819China Engineering Research Center of Frontier Technologies for Low-carbon Steelmaking(Ministry of Education) Shenyang 110819China

In recent years,medium entropy alloys have become a research hotspot due to their excellent physical and chemical *** controlling reasonable elemental composition and processing parameters,the medium entropy alloys can exhibit similar properties to high entropy alloys and have lower *** this paper,a FeCoNi medium entropy alloy precursor was prepared via sol-gel and coprecipitation methods,respectively,and FeCoNi medium entropy alloys were prepared by carbothermal and hydrogen *** phases and magnetic properties of FeCoNi medium entropy alloy were *** showed that FeCoNi medium entropy alloy was produced by carbothermal and hydrogen reduction at 1500℃.Some carbon was detected in the FeCoNi medium entropy alloy prepared by carbothermal *** alloy prepared by hydrogen reduction was uniform and showed a relatively high ***,the hydrogen reduction product exhibited better saturation magnetization and lower coercivity.

关键词： medium entropy alloy sol-gel co-precipitation carbothermal hydrogen reduction

Generation of highly-polarized high-energy brilliant γ-rays via laser-plasma interaction

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Matter and Radiation at Extremes 2020年第5期5卷 30-37页

作者： Kun Xue Zhen-Ke Dou Feng Wan Tong-Pu Yu Wei-Min Wang Jie-Ru Ren Qian zhao yong-tao zhao Zhong-Feng Xu Jian-Xing Li MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter School of ScienceXi’an Jiaotong UniversityXi’an 710049China Department of Physics National University of Defense TechnologyChangsha 410073China Department of Physics and Beijing Key Laboratory of Opto-Electronic Functional Materials and Micro-Nano Devices Renmin University of ChinaBeijing 100872China

The generation of highly polarized high-energy brilliantγ-rays via laser–plasma interaction is investigated in the quantum radiation-reaction *** employ a quantum electrodynamics particle-in-cell code to describe spin-resolved electron dynamics semiclassically and photon emission and polarization quantum mechanically in the local constant field *** an ultrastrong linearly polarized(LP)laser pulse irradiates a near-critical-density(NCD)plasma followed by an ultrathin planar aluminum target,the electrons in the NCD plasma are first accelerated by the driving laser to ultrarelativistic energies and then collide head-on with the laser pulse reflected by the aluminum target,emitting brilliant LPγ-rays via nonlinear Compton scattering with an average polarization of about 70%and energy up to hundreds of ***γ-rays can be produced with currently achievable laser facilities and will find various applications in high-energy physics and laboratory astrophysics.

关键词： polarized quantum interaction