Fast radio bursts(FRBs) are highly dispersed millisecond-duration radio bursts,[1,2]of which the physical origin is still not fully understood. FRB 20201124A is one of the most actively repeating FRBs. In this paper, ...Fast radio bursts(FRBs) are highly dispersed millisecond-duration radio bursts,[1,2]of which the physical origin is still not fully understood. FRB 20201124A is one of the most actively repeating FRBs. In this paper, we present the collection of 1863 burst dynamic spectra of FRB 20201124A measured with the Five-hundred-meter Aperture Spherical radio Telescope(FAST). The current collection, taken from the observation during the FRB active phase from April to June 2021, is the largest burst sample detected for any FRB so far. The standard PSRFITs format is adopted, including dynamic spectra of the burst, and the time information of the dynamic spectra, in addition, mask files help readers to identify the pulse positions are also provided. The dataset is available in Science Data Bank, with the link https://www.doi.org/10.57760/sciencedb.j00113.00076.展开更多
Numerous irradiation-induced gas bubbles are created in the nuclear fuel during irradiation, leading to the change of microstructure and the degradation of mechanical and thermal properties. The grain size of fuel is ...Numerous irradiation-induced gas bubbles are created in the nuclear fuel during irradiation, leading to the change of microstructure and the degradation of mechanical and thermal properties. The grain size of fuel is one of the important factors affecting bubble evolution. In current study, we first predict the thermodynamic behaviors of point defects as well as the interplay between vacancy and gas atom in both UO_(2) and U_(3)Si_(2) according to ab initio approach. Then, we establish the irradiation-induced bubble phase-field model to investigate the formation and evolution of intra-and inter-granular gas bubbles. The effects of fission rate and temperature on the evolutions of bubble morphologies in UO_(2) and U_(3)Si_(2) have been revealed. Especially, a comparison of porosities under different grain sizes is examined and analyzed. To understand the thermal conductivity as functions of grain size and porosity, the heat transfer capability of U_(3)Si_(2) is evaluated.展开更多
Endogenous opioid peptides(EOP)are the neurochemical basis of the anesthetic and analgesic effects of acupuncture,and the quantity of acupuncture stimulus can be controlled accurately by using electroacupuncture(EA).T...Endogenous opioid peptides(EOP)are the neurochemical basis of the anesthetic and analgesic effects of acupuncture,and the quantity of acupuncture stimulus can be controlled accurately by using electroacupuncture(EA).The present study explores the dose-effect relationship between EA with different parameters and the regulation of EOP system.In this paper,the intervention effects of EA on EOP system were specially discussed in terms of the single factor and the different combinations of the frequency,waveform and current intensity.This study shows that EOP system presents a frequency-response specificity.The low frequency of EA promotes the release of enkephalin,β-endorphin and endomorphin,the high one activates the dynorphin system selectively,and the intermediate frequency works on promoting the release of enkephalin andβ-endorphin,as well as dynorphin.Sparse-dense wave of EA may induce the release of enkephalin,β-endorphin,endomorphin and dynorphin,presenting a synergistic effect.However,the waveform of EA should be selected flexibly in clinical practice.Sometimes the better therapeutic effect can also be obtained with the continuous wave of EA.EOP system is involved in mediating appropriate intensity of EA,while the acupuncture effect generated by an extra strong EA stimulation refers to a kind of stress response of non-opioid mechanism.The different combinations of EA parameters result in various effects.The combination of EA parameters should be optimized in accordance with different diseases,which is valuable for guiding clinical practice and the development of EA therapy.展开更多
过渡金属硫化物是石墨负极材料的优异替代品,但其导电性差、充放电过程中体积膨胀严重.针对这些问题,本文从组成和结构设计的角度出发,通过自模板法简单高效地合成中空十二面体结构的NiS_(2)/CoS_(2)@HNC复合材料.研究表明,NiS_(2)/CoS_...过渡金属硫化物是石墨负极材料的优异替代品,但其导电性差、充放电过程中体积膨胀严重.针对这些问题,本文从组成和结构设计的角度出发,通过自模板法简单高效地合成中空十二面体结构的NiS_(2)/CoS_(2)@HNC复合材料.研究表明,NiS_(2)/CoS_(2)@HNC复合材料用于锂电池负极时显示出良好的电化学性能,在0.2 A g^(−1)电流密度下循环100圈能达到828 mA h g^(−1)的高可逆容量,还具有优异的倍率性能.这主要得益于材料中不同成分间的协同作用以及结构优势,中空氮碳层封装NiS_(2)、CoS_(2)纳米颗粒,缩短了Li+的传输路径,增强了材料的导电性,同时很好地缓解了Li+脱嵌过程中体积膨胀造成的容量衰减.展开更多
GaN films grown on(111)Si substrate with different lattice parameters of the AlN buffer layer by metal–organic chemical vapor deposition are studied.The stress states obtained by different test methods are compared a...GaN films grown on(111)Si substrate with different lattice parameters of the AlN buffer layer by metal–organic chemical vapor deposition are studied.The stress states obtained by different test methods are compared and it is found that the lattice parameter of the AlN buffer layer may have a significant effect on the stress state in the initial stage of subsequent GaN film growth.A larger compressive stress is beneficial to improved surface morphology and crystal quality of GaN film.The results of further orthogonal experiments show that an important factor affecting the lattice parameter is the growth rate of the AlN buffer layer.This work may be helpful for realizing simple GaN-on-Si structures and thus reducing the costs of growth processes.展开更多
基金supported by the National SKA Program of China (Grant Nos. 2020SKA0120100 and 2020SKA0120200)the National Natural Science Foundation of China (Grant Nos. 12041304, 11873067, 11988101, 12041303, 11725313, 11725314, 11833003, 12003028, 12041306, 12103089, U2031209, U2038105, and U1831207)+8 种基金the National Key Research and Development Program of China (Grant Nos. 2019YFA0405100, 2017YFA0402602, 2018YFA0404204, and 2016YFA0400801)Key Research Program of the Chinese Academy of Sciences (Grant No. QYZDJ-SSW-SLH021)Natural Science Foundation of Jiangsu Province (Grant No. BK20211000)Cultivation Project for FAST Scientific Payoff and Research Achievement of CAMS-CAS, the Strategic Priority Research Program on Space Science, the Western Light Youth Project of Chinese Academy of Sciences (Grant Nos. XDA15360000, XDA15052700, and XDB23040400)funding from the MaxPlanck Partner Group, the science research grants from the China Manned Space Project (Grant Nos. CMS-CSST2021-B11 and CMS-CSST-2021-A11)PKU development (Grant No. 7101502590)support from the XPLORER PRIZEsupported by Fundamental Research Funds for the Central Universities (Grant No. 14380046)the Program for Innovative Talents, Entrepreneur in Jiangsu。
文摘Fast radio bursts(FRBs) are highly dispersed millisecond-duration radio bursts,[1,2]of which the physical origin is still not fully understood. FRB 20201124A is one of the most actively repeating FRBs. In this paper, we present the collection of 1863 burst dynamic spectra of FRB 20201124A measured with the Five-hundred-meter Aperture Spherical radio Telescope(FAST). The current collection, taken from the observation during the FRB active phase from April to June 2021, is the largest burst sample detected for any FRB so far. The standard PSRFITs format is adopted, including dynamic spectra of the burst, and the time information of the dynamic spectra, in addition, mask files help readers to identify the pulse positions are also provided. The dataset is available in Science Data Bank, with the link https://www.doi.org/10.57760/sciencedb.j00113.00076.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.U2167217,12205286,and 11905025)the National MCF Energy Research and Development Program of China (Grant No.2018YFE0308105)。
文摘Numerous irradiation-induced gas bubbles are created in the nuclear fuel during irradiation, leading to the change of microstructure and the degradation of mechanical and thermal properties. The grain size of fuel is one of the important factors affecting bubble evolution. In current study, we first predict the thermodynamic behaviors of point defects as well as the interplay between vacancy and gas atom in both UO_(2) and U_(3)Si_(2) according to ab initio approach. Then, we establish the irradiation-induced bubble phase-field model to investigate the formation and evolution of intra-and inter-granular gas bubbles. The effects of fission rate and temperature on the evolutions of bubble morphologies in UO_(2) and U_(3)Si_(2) have been revealed. Especially, a comparison of porosities under different grain sizes is examined and analyzed. To understand the thermal conductivity as functions of grain size and porosity, the heat transfer capability of U_(3)Si_(2) is evaluated.
基金Supported by the National Natural Science Foundation of China:No.815740786th Cycle Medical Key Specialty Construction Project of Jinshan District:JSZK2019H04Three Years Action Plan of Shanghai to Further Accelerate the Development of Traditional Chinese Medicine:2018-2020。
文摘Endogenous opioid peptides(EOP)are the neurochemical basis of the anesthetic and analgesic effects of acupuncture,and the quantity of acupuncture stimulus can be controlled accurately by using electroacupuncture(EA).The present study explores the dose-effect relationship between EA with different parameters and the regulation of EOP system.In this paper,the intervention effects of EA on EOP system were specially discussed in terms of the single factor and the different combinations of the frequency,waveform and current intensity.This study shows that EOP system presents a frequency-response specificity.The low frequency of EA promotes the release of enkephalin,β-endorphin and endomorphin,the high one activates the dynorphin system selectively,and the intermediate frequency works on promoting the release of enkephalin andβ-endorphin,as well as dynorphin.Sparse-dense wave of EA may induce the release of enkephalin,β-endorphin,endomorphin and dynorphin,presenting a synergistic effect.However,the waveform of EA should be selected flexibly in clinical practice.Sometimes the better therapeutic effect can also be obtained with the continuous wave of EA.EOP system is involved in mediating appropriate intensity of EA,while the acupuncture effect generated by an extra strong EA stimulation refers to a kind of stress response of non-opioid mechanism.The different combinations of EA parameters result in various effects.The combination of EA parameters should be optimized in accordance with different diseases,which is valuable for guiding clinical practice and the development of EA therapy.
文摘过渡金属硫化物是石墨负极材料的优异替代品,但其导电性差、充放电过程中体积膨胀严重.针对这些问题,本文从组成和结构设计的角度出发,通过自模板法简单高效地合成中空十二面体结构的NiS_(2)/CoS_(2)@HNC复合材料.研究表明,NiS_(2)/CoS_(2)@HNC复合材料用于锂电池负极时显示出良好的电化学性能,在0.2 A g^(−1)电流密度下循环100圈能达到828 mA h g^(−1)的高可逆容量,还具有优异的倍率性能.这主要得益于材料中不同成分间的协同作用以及结构优势,中空氮碳层封装NiS_(2)、CoS_(2)纳米颗粒,缩短了Li+的传输路径,增强了材料的导电性,同时很好地缓解了Li+脱嵌过程中体积膨胀造成的容量衰减.
基金supported by Beijing Municipal Science&Technology Commission,Administrative Commission of Zhongguancun Science Park(Grant Nos.Z211100007921022 and Z211100004821001)the National Natural Science Foundation of China(Grant Nos.62034008,62074142,62074140,61974162,61904172,61874175,62127807,and U21B2061)+3 种基金Key Research and Development Program of Jiangsu Province(Grant No.BE2021008-1)Beijing Nova Program(Grant No.202093)Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB43030101)Youth Innovation Promotion Association of Chinese Academy of Sciences(Grant No.2019115).
文摘GaN films grown on(111)Si substrate with different lattice parameters of the AlN buffer layer by metal–organic chemical vapor deposition are studied.The stress states obtained by different test methods are compared and it is found that the lattice parameter of the AlN buffer layer may have a significant effect on the stress state in the initial stage of subsequent GaN film growth.A larger compressive stress is beneficial to improved surface morphology and crystal quality of GaN film.The results of further orthogonal experiments show that an important factor affecting the lattice parameter is the growth rate of the AlN buffer layer.This work may be helpful for realizing simple GaN-on-Si structures and thus reducing the costs of growth processes.
