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Can the inner gap sparking take place in millisecond pulsars?

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Chinese Journal of Astronomy and Astrophysics 2003年第5期3卷 443-452页

作者： Hong-Guang Wang, Guo-Jun qiao and Ren-xin XuDepartment of Astronomy, Peking University, Beijing 100871 Department of Astronomy Peking University Beijing 100871

The inner vacuum gap model has become the foundation stone of most theorieson pulsar radio emission. The fundamental picture of this model is the sparking, which wasconjectured to be induced by magnetic absorption of background gamma photons. However, a questionis, can the sparking be triggered in the millisecond pulsars (MSPs) with magnetic fields (B) onlyabout 10~8 G? We investigate this problem by including the pair production above the inner *** the assumption that the magnetic field is dipolar, our results show the background gamma-rayemission can not be the key factor that triggers the sparking, at least not in MSPs with B ～ 10~8G, if the temperature in the polar cap region is only so high as is observed (< 4 x 10~6K). Someother mechanisms are required.

关键词： pulsar: general gamma rays magnetic fields

Relationship between depression,smartphone addiction,and sleep among Chinese engineering students during the COVID-19 pandemic

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World Journal of Psychiatry 2023年第6期13卷 361-375页

作者： Wen-Juan Gao Yan Hu Jun-Lin Ji xin-qiao Liu Institute of Higher Education Beihang UniversityBeijing 100191China School of Public Administration Beihang UniversityBeijing 100191China Research Center for Beijing Higher Education Development Beihang UniversityBeijing 100191China School of Education Tianjin UniversityTianjin 300350China

BACKGROUND Existing research has demonstrated that depression is positively related to smartphone addiction, but the role of sleep has not been discussed thoroughly, especially among engineering undergraduates affected by the coronavirus disease 2019 *** To evaluate sleep as a mediator of the association between smartphone addiction and depression among engineering *** Using a multistage stratified random sampling method, a cross-sectional survey was conducted among 692 engineering undergraduates from a top engineering university in China, and data were collected by self-reported electronic questionnaires. The data included demographic characteristics, such as age, gender, the Smartphone Addiction Scale-Short Version(SAS-SV), the 9-item Patient Health Questionnaire, and the Pittsburgh Sleep Quality Index. Pearson correlation and multiple linear regression analyses were used to examine the association between smartphone addiction and depression, while structural equation models were established to evaluate the possible mediating role of *** Based on the cutoffs of the SAS-SV, the rate of smartphone addiction was 63.58 percent, with 56.21 percent for women and 65.68 percent for men, among 692 engineering students. The prevalence of depression among students was 14.16 percent, with 17.65 percent for women, and 13.18 percent for men. Smartphone addiction was positively correlated with depression, and sleep played a significant mediating effect between the two, accounting for 42.22 percent of the total effect. In addition, sleep latency, sleep disturbances, and daytime dysfunction significantly mediated the relationship between depression and smartphone addiction. The mediating effect of sleep latency was 0.014 [P < 0.01;95% confidence interval(CI): 0.006-0.027], the mediating effect of sleep disturbances was 0.022(P < 0.01;95%CI: 0.011-0.040), and the mediating effect of daytime dysfunction was 0.040(P < 0.01;95%CI: 0.024-0.059). Th

关键词： Smartphone addiction Depression Pittsburgh Sleep Quality Index Engineering students COVID-19 Mediating effect

Preliminary Studies on Thickness of Nondestructive Rice (Oryza sativa L.) Leaf Blade

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Agricultural Sciences in China 2007年第7期6卷 802-807页

作者： CHEN You-ding ZHANG Xu ZHOU xin-qiao CHEN Guan-hua Rice Research Institute Guangdong Academy of Agricultural Sciences Guangzhou 510640 P.R. China

Two varieties, Yuexinzhan and Guangchao 3, were used to study leaf thickness in rice in this experiment. The thickness of the leaf blade was measured by the nondestructive leaf thickness instrument, which was modified from the thickness instrument for steel objects （John Bull, England）. The contacting area between the leaf and the probe of the instrument was 0.5 cm^2. There was no significant difference between the thickness of steel materials measured by the nondestructive rice leaf thickness instrument and the micrometer. The correlation between the thickness of the rice leaf blade measured by the nondestructive rice leaf thickness instrument and the specific leaf weight （SLW） was significant （P 〈 0.05 or P〈 0.01）. The results also showed that the rice leaf thickness was uneven and asymmetric. The thickness and SLW of flag leaf tended to increase from the base to the tip of the leaf blade. The middle part of the second and third top leaf was the thickest, but no significant difference in thickness between the basal part and the fore part was found. Drawing a line on the main vein in the top three leaves, the left part was thinner than the right part. The thickness of the lower leaves （6/0-9/0） on the main culm tended to increase with increasing positions of the leaves in the early and middle stages, but the tendency was not the same for the higher leaves （10/0 upwards）, although the higher leaves （10/0 upward） were thicker than the lower leaves （9/0 or downward）. Furthermore, different CO2 concentrations （550±30, 460 ± 30 μmol mol^-1） in the growth boxes had no effect on the thickness of rice leaf blades. It can be concluded that the measurement of rice leaf thickness using the nondestructive rice leaf thickness instrument is simple, precise, and nondestructive.

关键词： paddy rice leaf thickness nondestructive rice leaf thickness instrument

Proton loss of inner radiation belt during geomagnetic storm of 2018 based on CSES satellite observation

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Chinese Physics B 2021年第12期30卷 664-670页

作者： Zhen-Xia Zhang Xu-Hui Shen xin-qiao Li Yong-Fu Wang National Institute of Natural Hazards MEMCBeijing 100085China Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China Institute of Space Physics and Applied Technology Peking UniversityBeijing 100871China

The proton distribution in inner radiation belt is often affected by strong geomagnetic storm *** on the data of the sun-synchronous CSES satellite,which carries with several high energy particle payloads and was launched in February 2018,we analyzed the extensive proton variations in the inner radiation belt in a wide energy range of 2 MeV-220 MeV during 2018 major geomagnetic *** result indicates that the loss mechanism of protons was energy dependence which is consistent with some previous *** protons at low energy 2 MeV-20 MeV,the fluxes were decreased during main phase of the storm and did not come back quickly during the recovery phase,which is likely to be caused by Coulomb collision due to neutral atmosphere density *** higher energy 30 MeV-100 MeV,it was confirmed that the magnetic field line curvature scattering plays a significant role in the proton loss phenomenon during this *** highest energies>100 MeV,the fluxes of protons kept a stable level and did not exhibit a significant loss during this storm.

关键词： proton loss the inner radiation belt CSES satellite field line curvature scattering

Two new α,β-unsaturated butyrolactone derivatives from Pleione bulbocodioides

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Chinese Chemical Letters 2007年第9期18卷 1075-1077页

作者： xin qiao Liu Wen Yuan Gao Yuan Qiang Guo Tie Jun Zhang Lu Lu Yan School of Pharmaceutical Science and Technology Tianjin University Tianjin 300072 China Department of Pharmaceutical Sciences Nankai University Tianjin 300071 China Tianjin Institute of Pharmaceutical Research Tianjin 300193 China

Two new α,β-unsaturated butyrolactone derivatives, 4-(4″-hydroxybenzyl)-3-(3′-hydroxy-phenethyl)furan-2(5H)-one (1) and 3-(3′-hydroxyphenethyl)furan-2(5H)-one (2), together with one known phenolic compound (3), were isolated from the tubers of Pleione bulbocodioides (Franch.) Rolfe. Their structures were elucidated by analysis of spectroscopic data.

关键词： Pleione bulbocodioides α,β-Unsaturated butyrolactone Phenolic compound

A new phenanthro [2,3-b] furan from Pleione bulbocodioides

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Chinese Chemical Letters 2007年第9期18卷 1089-1091页

作者： xin qiao Liu Wen Yuan Gao Yuan Qiang Guo Tie Jun Zhang Lu Lu Yan School of Pharmaceutical Science and Technology Tianjin University Tianjin 300072 China School of Chemical and Environmental Engineering Hubei University of Technology Wuhan 430068 China Department of Pharmaceutical Sciences Nankai University Tianjin 300071 China Tianjin Institute of Pharmaceutical Research Tianjin 300193 China

A novel phenanthro [2,3-b] furan 1, named (3-hydroxy-9-(4′-hydroxy-3′-methoxyphenyl)-11-methoxy-5,6,9,10-tetrahydrophenanthro [2,3-b] furan-10-yl) methyl acetate, and two known phenolic compounds were isolated from ... 详细信息

关键词： Pleione bulbocodioides Phenanthro [2,3-b] furan Phenolic compounds Cytotoxity

Corrosion and Cavitation Erosion Behaviors of Two Marine Propeller Materials in Clean and Sulfide-Polluted 3.5% NaCl Solutions

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Acta Metallurgica Sinica(English Letters) 2017年第8期30卷 712-720页

作者： Qi-Ning Song Nan Xu Ye-Feng Bao Yong-Feng Jiang Wei Gu Yu-Gui Zheng Yan-xin qiao College of Mechanical and Electrical Engineering Hohai University Changzhou 213022 China Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal Research Chinese Academy of SciencesShenyang 110016 China College of Materials Science and Engineering Jiangsu University of Science and Technology Zhenjiang 212003China

The corrosion and cavitation erosion behaviors of two main materials for ship propellers, i.e., nickel-aluminum bronze （NAB） and manganese-nickel-aluminum bronze （MAB） were investigated in a clean and sulfide-polluted 3.5% NaCl solutions. The presence of sulfide increased the corrosion damage of both NAB and MAB by rendering the corrosion product film thicker, more porous and less protective. For MAB, the formation of Fe oxides/sulfides within the corrosion product film may reduce the film compactness and responsible for the lower corrosion resistance, compared with NAB. The presence of sulfide caused the occurrence of more severe corrosion on the surface and therefore further enhanced the cavitation erosion damage. Compared with the result in the clean solution, the cavitation-erosion mass loss rate was raised by a factor of about 11.88% for MAB, and 58.6% for NAB. For NAB, the mechanical erosion dominated the damage in the clean solution, while the cavitation erosion synergy made a significant contribution to the overall damage in the sulfide-polluted solution. For MAB, it was the mechanical damage that contributed mainly to the cavitation erosion damage in both solutions. The exfoliation of large-sized κ phase and the cleavage rupture of β phases resulted in lower cavitation erosion resistance of MAB, compared with NAB.

关键词： Copper alloy Cavitation erosion Corrosion Sulfide

Effect of Ni Interlayer on Cavitation Erosion Resistance of NiTi Cladding by Tungsten Inert Gas(TIG)Surfacing Process

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Acta Metallurgica Sinica(English Letters) 2020年第3期33卷 415-424页

作者： Zhen-Ping Shi Zheng-Bin Wang Ji-Qiang Wang Yan-xin qiao Huai-Ning Chen Tian-Ying Xiong Yu-Gui Zheng CAS Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China School of Materials Science and Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China

The NiTi cladding with/without Ni interlayer was prepared on stainless steel(SS) by tungsten inert gas(TIG) surfacing process,aiming at achieving good cavitation erosion *** ranking according to the cavitation erosion resistance is NiTi plate> NiTi-Ni-TIG cladding> NiTi-TIG cladding> *** better cavitation erosion resistance of NiTi-TIG and NiTi-Ni-TIG claddings than SS substrate is due to their higher micro-hardness and ***,the existence of Ni interlayer can decrease the amount of brittle intermetallic compounds,such as Fe2 Ti,and inhibit the crack generation,which results in the higher cavitation erosion resistance of NiTi-Ni-TIG compared with NiTi-TIG ***,the cavitation erosion resistance of NiTi cladding prepared by TIG surfacing process can be improved by employing Ni interlayer.

关键词： Cavitation erosion NiTi Cladding Tungsten inert gas surfacing process Ni interlayer

Effect of solidification mode on microstructure evolution and properties of magnesium alloy with long-period stacking ordered phase

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Journal of Iron and Steel Research International 2024年第5期31卷 1127-1138页

作者： Hao Li Hong-mei Chen Xu Zhang Qian-hao Zang Jing Zhang Di Feng Yan-xin qiao Yu-hang Guo School of Materials Science and Engineering Jiangsu University of Science and TechnologyZhenjiang212100JiangsuChina School of Metallurgy and Materials Engineering Jiangsu University of Science and TechnologySuzhou215600JiangsuChina

The solidification methods of electromagnetic stirring(EMS)and non-electromagnetic stirring were employed to prepare Mg–6Gd–3Y–xZn–0.6Zr(x=1,1.5,2,3)*** evolution of alloy microstructures and the changes in properties were analyzed for different Zn *** has been observed that in alloys without electromagnetic stirring,as the Zn content increases,the alloy structure gradually *** primary second phase transitions from Mg5RE phase to long-period stacking ordered(LPSO)phase,resulting in improved hardness and *** alloys subjected to electromagnetic stirring,there is a relatively higher content of the second phase,primarily consisting of LPSO *** applying electromagnetic stirring,the quantity and the type of LPSO phase in the alloy *** alloy structure becomes more uniform with electromagnetic stirring,resulting in increased hardness and reduced hardness gradients within the *** mechanical properties of alloys with electromagnetic stirring are superior to those without electromagnetic stirring.

关键词： Rare earth magnesium alloy LPSO phase Electromagnetic stirring Casting Property