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Distinct MLT asymmetry of auroral kilometric radiation observed by the FAST satellite

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Earth and Planetary Physics 2025年第1期9卷 188-193页

作者： JiaWen Tang Sai Zhang FuLiang Xiao HongMing Yang Si Liu YiHua He chang Yang YuYue jin ZhouKun Deng Ping Li Archie James Johnston School of Physics and Electronic Sciences Changsha University of Science and TechnologyChangsha 410114China Hunan Province Higher Education Key Laboratory of Modeling and Monitoring on the Near-Earth Electromagnetic Environments Changsha University of Science and TechnologyChangsha 410114China School of Electrical and Information Engineering Changsha University of Science and TechnologyChangsha 410114China

Auroral Kilometric Radiation (AKR) is a common radio emission,which can contribute to the magnetosphere-ionosphereatmosphere co u *** emissions have been observed in all magnetic planet magnetospheres of the solar *** this study,using observations from the FAST satellite from 30 August 1996 to 9 September 2001,the distribution of AKR in altitude=500-4500 km and invariant latitude (|ILAT|)=60°-80°has been analyzed.63045 AKR samples have been identified with~48%(52%) samples on the dayside (nightside).Of considerable interest,there is a distinct MLT asymmetry with the high occurrence rate in MLT=05-08 and 18-22(02-05 and 12-17) in the northern (southern) *** distinct MLT asymmetry is associated with the direction of Bxof the interplaneta ry magnetic *** addition,the occurrence rate on the nightside clearly increases as the AE^(*) index *** study further enriches the information and understanding of AKR in the magnetosphere as well as other similar radio emissions.

关键词： asymmetry auroral kilometric radiation interplanetary magnetic field

循环加载与卸围压组合扰动下红砂岩损伤破裂与渗透特性

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岩土工程学报 2025年第1期47卷 48-56页

作者：姚玮俞缙周先齐常方强常旭厦门理工学院土木工程与建筑学院福建厦门361024 华侨大学福建省隧道与城市地下空间工程技术研究中心福建厦门361021

为探究深地工程开挖诱导岩体损伤破裂及渗透性演化规律,开展了同步测定波速与渗透率的循环加载与卸围压组合扰动三轴试验,研究了不同条件下红砂岩的损伤与渗透性演化规律。结果表明:①岩石在不同组合扰动阶段具有不同的应力应变曲线形态... 详细信息

为探究深地工程开挖诱导岩体损伤破裂及渗透性演化规律,开展了同步测定波速与渗透率的循环加载与卸围压组合扰动三轴试验,研究了不同条件下红砂岩的损伤与渗透性演化规律。结果表明:①岩石在不同组合扰动阶段具有不同的应力应变曲线形态,其末端形态取决于在何种扰动阶段破坏,初始应力比为决定组合扰动诱发岩石破坏难易的主要因素;②总峰值轴向应变随初始应力比增大而增大,其中组合扰动轴向应变占比始终较低,总峰值体积应变绝对值随初始应力比增大而先增大后减小,其中组合扰动体积应变占比较高;③在初始加载阶段,波速增大,渗透率降低,在组合扰动阶段,波速下降,渗透率增加,且损伤与体积应变近似呈线性关系,损伤与渗透率随扰动次数增加均呈先慢后快的增长趋势,且拐点分别近似在一条直线上;④岩石在组合扰动卸围压阶段破坏为单剪切破坏模式,在组合扰动循环加载阶段破坏为共轭剪切破坏模式;⑤双高(高初始应力比与高初始围压)条件将显著加剧岩体开挖失稳破坏风险。

关键词：深地工程组合扰动力学特性损伤渗透性

Recent progress on photoactive nonprecious transition-metal complexes

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Science China Chemistry 2025年第1期68卷 46-95页

作者： Zhong-Liang Gong Hong-Jie Zhang Yan Cheng Jianxun Liu Yuhan Ai Yaqin Li Zhihui Feng Qiong Zhang Shaolong Gong Yong Chen chang-Jiang Yao Yuan-Yuan Zhu Liang-jin Xu Yu-Wu Zhong CAS Key Laboratory of Photochemistry Institute of Chemistry Chinese Academy of Sciences State Key Laboratory of Structural Cemistry Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences School of Chemistry and Chemical Engineering Anhui Key Laboratory of Advanced Catalytic Materials and Reaction EngineeringHefei University of Technology State Key Laboratory of Explosion Science and Safety Protection School of Mechatronical Engineering Beijing Institute of Technology College of Chemistry and Molecular Sciences Hubei Key Lab on Organic and Polymeric Optoelectronic Materials Wuhan University School of Chemistry and Chemical Engineering Anhui University Key Laboratory of Photochemical Conversion and Optoelectronic Materials & CAS-HKU Joint Laboratory on New Materials Technical Institute of Physics and Chemistry Chinese Academy of Sciences

Photoactive complexes of nonprecious transition metals, mainly including those in the first-row and partially the second-row of the Periodic table of elements, have received increasing attention in view of their low cost and long-term sustainability. They are recognized as promising alternatives to noble transition metal complex congeners that have been extensively studied in optoelectronic devices, artificial photosynthesis, photocatalysis, biodiagnostics, and therapeutics, etc. This review is devoted to a comprehensive summary on the classical and recent advances on photoactive nonprecious transition metal complexes, including photoactive Zr, V, Cr, Mo, and W complexes, Mn complexes and hybrids, Fe, Co, Ni, and Cu complexes, and Zn and Cd complexes and hybrids. A particular focus is given on the molecular design, modulation of photophysical and photochemical properties, and applications of the representative and lately-developed nonprecious metal complexes. In addition, a perspective on the future development in this field is provided at the end of this review.

关键词： photoactive metal complexes earth-abundant metals nonprecious metal complexes luminescence photochemistry

A Key Recovery System Based on Password-Protected Secret Sharing in a Permissioned Blockchain

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Computers, Materials & Continua 2020年第10期65卷 153-170页

作者： Gyeong-jin Ra chang-hyun Roh Im-Yeong Lee First Soonchunhyang University Asan-si31538Korea

In today’s fourth industrial revolution,various blockchain technologies are being actively researched.A blockchain is a peer-to-peer data-sharing structure lacking central *** a user wishes to access stored data,she/he must employ a private key to prove ownership of the data and create a *** the private key is lost,blockchain data cannot be *** solve such a problem,public blockchain users can recover the key using a wallet ***,key recovery in a permissioned blockchain(PBC)has been but little *** PBC server is Honest-but-Curious(HBC),and should not be able to learn anything of the user;the server should simply recover and store the *** server must also be resistant to malicious ***,key recovery in a PBC must satisfy various security ***,we present a password-protected secret sharing(PPSS)key recovery system,protected by a secure password from a malicious key storage server of a *** describe existing key recovery schemes and our PPSS scheme.

关键词： Password-protected secret sharing key recovery blockchain wallet security

Polygonal multi-polymorphed Li4Ti5Oi2@rutile TiO2 as anodes in lithium-ion batteries

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Nano Research 2019年第4期12卷 897-904页

作者： chang hyun Hwang Hee-eun Kim Inho Nam jin Ho Bang Department ofBionano Technology Hanyang University 55 Hanyangdaehak-ro Sangnok-gu Ansan Gyeonggi-do 15588 Republic of Korea School of Chemical Engineering & Materials Science Chung-Ang University 84 Heukseok-ro Dongjak-gu Seoul 06974 Republic of Korea Department of Chemical and Molecular Engineering Hanyang University 55 Hanyangdaehak-ro Sangnok-gu Ansan Gyeonggi-do 15588 Republic of Korea

Li4Ti50i2 (LTO) has attracted considerable attention in lithium-ion battery (LIB) applications because of its favorable characteristics as an anode material. Despite its promise, the widespread use of LTO is still limited primarily due to its intrinsically poor electric and ionic con ductivities and high surface reactivity. To address these issues, we desig ned polyg onal nano architectures composed of various Li-Ti oxide crystal polymorphs by a facile synthesis route. Depending on the pH condition, this synthesis approach yields multi-polymorphed Li-Ti oxides where the interior is dominantly composed of a Li-rich phase and the exterior is a Li-deficient (or Li-free) phase. As one of these variations, a polygonal LTO-rutile TiO2 structure is formed. The rutile TiO2 on the surface of this LTO composite significantly improves the kinetics of Li^+ insertion/extraction because the channel along the o-axis in TQ2 provides a Li^+ highway due to the significantly low energy barrier for Li^+ diffusion. Moreover, the presenee of rutile TiO2, which is less reactive with a carbonate-based electrolyte, ensures Iong-term stability by suppress)ng the undesirable interfacial reaction on LTO.

关键词： micro-polygon structure Li-Ti oxide multi-polymorphs Li4Ti5Oi2@ rutile TiO2 anode lithium-ion batteries

Structural considerations in friction welding of hybrid Al_2O_3-reinforced aluminum composites

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Transactions of Nonferrous Metals Society of China 2011年第A1期21卷 42-46页

作者： In-Duck PARK Choon-Tae LEE hyun-Soo KIM Woo-jin CHOI Myung-chang KANG Busan Metropolitan City Hall Fundamental Industries Division 2001 Jungang-ro Yeonje-gu Busan 611-735 Korea Department of Automotive & Mechanical Engineering Silla University Research & Development Center Sam-Ho precision 1256-1 Daejeo2-dong Gangseo-gu Busan 618-807 Korea National Core Research Center for Hybrid Materials Solution Pusan National University

Comparative studies on the relationship between the welding parameters and joining efficiency in the friction welding of hybrid Al203-reinforced aluminum composites were conducted. Metal matrix composites （MMCs） with 37% （volume fraction） aluminum particle were joined by friction welding. The results show that the effects of the rotation speed on the reduction rate of particle size are greater than those of the upset pressure, and the area of the MMC weld zone decreases as the joining efficiency increases, while it is considered that the joining efficiency does not increase as the reduction rate of particle size decreases. During the macro-examination of the bonding interlace, a gray discolored region was observed on the bonding interface, and the center of the region was dark gray. After the micro-examination of the bonding interface, base metal made some second particulate formed by condensed alumina particulate but discoloration part distributed minute alumina particulate without second particulate. Consequently, it was also observed that rotational speed of 3 000 r/min and upset pressure of 63.6 MPa showed a very ***.

关键词： friction welding hybrid aluminum composite bonding interface joining efficiency metal matrix composite

Fabrication of curved micro structures on photoresist layer

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Transactions of Nonferrous Metals Society of China 2011年第A1期21卷 100-103页

作者： Jae Sung YOON Tae-jin JE Doo-Sun CHOI Sung Hwan chang Kyung-hyun WHANG Nano Mechanical Systems Research Division Korea Institute of Machinery and Materials (KIMM) Daejeon 305-343 Korea

A novel fabrication process for micro patterns with curvature was introduced. The curved structures were made by compensating rectangular micro structures with liquid photoresist layer. Because of the surface tension of the liquid in micro scale, various shapes of meniscus can he made on the micro channels. The micro channels were made on the silicon suhstrate in advance, and then the liquid layer was coated on the micro channels. From the nature of liquid behavior, the curved patterns with smooth surface are obtained, which cannot be made easily with the conventional mechanical machining, as well as with the microfabrication processes, such as wet and dry etching. With this principle, it is expected that the smooth and curved surfaces can be made by simple processes and the results can be applied widely, such as optical patterns.

关键词： micro pattern liquid layer MEMS micro channel silicon substrate

Recent Progresses of the DAMPE Mission

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空间科学学报 2024年第4期44卷 633-642页

作者： chang jin Key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjing 210033 School of Astronomy and Space Science University of Science and Technology of ChinaHefei 230026

The DArk Matter Particle Explorer(DAMPE)is a space high-energy particle andγ-ray detector whose major scientific goals are the indirect detection of dark matter particles,the origin of cosmic rays and highenergyγ-ray *** its successful launch in December 2015,the DAMPE has been operated smoothly in orbit for more than 8 *** direct measurements of the boron-to-carbon and boron-to-oxygen flux ratios,and the proton+Helium spectrum up to 316 TeV have been obtained,revealing new spectral features with very high *** search results ofγ-ray spectral line and fractionally charged particles indicate a good potential of DAMPE for indirect dark matter detection and new physical discovery in *** DAMPE measurements are expected to significantly advance our understanding of the fundamental problems in astroparticle physics.

关键词： DAMPE Dark matter Indirect detection Cosmic rays

Groundwater contamination and natural attenuation capacity at a petroleum spilled facility in Korea

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Journal of Environmental Sciences 2011年第10期23卷 1650-1659页

作者： hyun-Mi Choi jin-Yong Lee Department of Geology Kangwon National University

As a remedial option, the natural attenuation capacity of a petroleum contaminated groundwater at a military facility was examined. Hydrogeological conditions, such as high water level, permeable uppermost layer and frequent heavy rainfall, were favorable to natural attenuation at this site. The changes in the concentrations of electron acceptors and donors, as well as the relevant hydrochemical conditions, indicated the occurrence of aerobic respiration, denitrification, iron reduction, manganese reduction and sulfate reduction. The calculated BTEX expressed biodegradation capacity ranged between 20.52 and 33.67 mg/L, which appeared effective for the reduction of the contaminants levels. The contribution of each electron accepting process to the total biodegradation was in the order： denitrification 〉 iron reduction 〉 sulfate reduction 〉 aerobic respiration 〉 manganese reduction. The BTEX and benzene point attenuation rates were 0.0058-0.0064 and 0.0005-0.0032 day-1, respectively, and the remediation time was 0.7-1.2 and 2.5-30 years, respectively. The BTEX and benzene bulk attenuation rates were 8.69 × 10^-4 and 1.05 × 10^-3 day-l, respectively, and the remediation times for BTEX and benzene were 7.2 and 17.5 years, respectively. However, most of the natural attenuation occurring in this site can be attributed to dilution and dispersion. Consequently, the biodegradation and natural attenuation capacities were good enough to lower the contaminants levels, but their rates appeared to be insufficient to reach the remediation goal within a reasonable time frame. Therefore, some active remedial measures would be required.

关键词： petroleum contaminated site BTEX electron acceptor expressed biodegradation capacity natural attenuation