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Discovery of the largest natural carbon onions on Earth

Science China Earth Sciences 2022年第9期65卷 1736-1750页

作者： Yilin CHEN Yong QIN jiuqing li Zhuangfu li Tianyu YANG Ergang liAN Key Laboratory of Coalbed Methane Resources and Reservoir Formation Process of the Ministry of Education China University of Mining and TechnologyXuzhou 221008China School of Resources and Geosciences China University of Mining and TechnologyXuzhou 221116China State Key Laboratory of Marine Geology Tongji UniversityShanghai 200092China

The synthesis of carbon onions in the laboratory by various methods is common;however, naturally occurring carbon onions have only been found in a few geological samples on Earth. This study used high-resolution transmission electron microscopy to identify natural carbon onions in seven intrusion-affected coal samples collected from Permian coal-bearing strata in the Yongan Coalfield, Fujian Province, South China. This study identified the largest natural carbon onions ever recorded on Earth;their outer diameter was ~55 nm. Granite porphyry intrusions and quartz hydrothermal veins are abundant in the Permian coal-bearing strata in this coalfield. All samples collected were tectonically deformed coals with highly developed structural fractures, friction mirror planes, and maximum vitrinite reflectance values of 4.0–9.5%. Natural carbon onions observed in the coal samples had single or multiple cores, with 24–46 graphitic shells characterized by outer diameters of 24–55 nm. The maximum vitrinite reflectance, outer diameter, and graphitic shell number of carbon onions in the intrusion-affected coal were positively correlated, indicating that the carbon onions were secondary products formed during coal metamorphism owing to magmatic intrusion. Our results suggest that carbon onions in intrusion-affected coal are synthesized by chemical vapor deposition. We speculate that natural carbon onions exist mainly in fractures or cavities, similar to vapor-deposited pyrolytic carbon, which is the leading cause of the uneven distribution of carbon onions in intrusion-affected coals in the study area.

关键词： Onion-like fullerenes Intrusion-affected coal Chemical vapor deposition HRTEM Coal metamorphism

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Transient Monte Carlo simulation of phonon transport in silicon nanofilms with the local heat source

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Science China(Technological Sciences) 2024年第7期67卷 2087-2098页

作者： li JiaQi CAI jiuqing li Rui liU ZhiChun liU Wei School of Energy and Power Engineering Huazhong University of Science and TechnologyWuhan 430074China Wuhan Second Ship Design and Research Institute Wuhan 430205China

Accurate prediction of junction temperature is crucial for the efficient thermal design of silicon nano-devices. In nano-scale semiconductor devices, significant ballistic effects occur due to the mean free path of phonons comparable to the heat source size and device scale. We employ a three-dimensional non-gray Monte Carlo simulation to investigate the transient heat conduction of silicon nanofilms with both single and multiple heat sources. The accuracy of the present method is first verified in the ballistic and diffusion limits. When a single local heat source is present, the width of the heat source has a significant impact on heat conduction in the domain. Notably, there is a substantial temperature jump at the boundary when the heat source width is 10 *** increasing heat source width, the boundary temperature jump weakens. Furthermore, we observe that the temperature excitation rate is independent of the heat source width, while the temperature influence range expands simultaneously with the increase in heat source width. Around 500 ps, the temperature and heat flux distribution in the domain stabilize. In the case of dual heat sources, the hot zone is broader than that of a single heat source, and the temperature of the hot spot decreases as the heat source spacing increases. However, the mean heat flux remains unaffected. Upon reaching a spacing of 200 nm between the heat sources, the peak temperature in the domain remains unchanged once a steady state is reached. These findings hold significant implications for the thermal design of silicon nano-devices with local heat sources.

关键词： phonon transport Monte Carlo simulation transient heat conduction silicon nanofilms local heat source

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Electrochemical impedance characteristics of LC4 aluminum alloy treated with ZH1 technique

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Rare Metals 2002年第1期21卷 48-55页

作者： ZHANG Wei, li jiuqing, WU Yinshun, and HE Jianping Corrosion and Protection Center, University of Science and Technology Beijing, Beijing 100083, China Corrosion and Protection Center University of Science and Technology Beijing 北京 100083

Zhl technique was used to form a corrosion resistant layer on LC4alloy. the composition of the layer was studied by X-rayphotoelectron spectroscopy (XPS). It is found that the layer iscomposed of oxides of metals on the sub- strate, such as Al_2O_3,ZnO, MgO_, CuO, and MnO_2. The elecrochemical impedance spectrums(EIS) of LC4 aluminum alloy specimen were measured in NaCl solutionsto study the mechanism of the corrosion resistance of the alloytreated with Zh1 technique.

关键词： aluminium alloy rare earth metal electrochemical impedance corrosion

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Cathodic electrolysis method of depositing cerium conversion films on industrial pure aluminum

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Rare Metals 2002年第2期21卷 95-100页

作者： ZHANG Wei, li jiuqing, WU Yinshun, SHEN Defeng, and HE JianpingDepartment of Surface Science & Corrosion Engineering, University of Science and Technology Beijing, Beijing 100083, China Department of Surface Science & Corrosion Engineering University of Science and Technology Beijing 北京 100083

Two two-step techniques, called TS2/TS7 and TS3/TS7, respectively,have been developed to form cerium conversion films on the surface ofindustrial pure aluminum. The tested material was cathodicallyelectrolyzed in the al- kaline solution containing cerium salt, anduniform films containing cerium were obtained after the two-steptreatment. It is found that the films obtained by TS2/TS7 and TS3/TS7techniques are about 4.0 and 3.0 um in thickness, respectiv- Ely. Thematerial has better corrosion resistance in the chloride solutionafter the two-step electrolysis treatent compar- Ed with the one-steptreated and naked specimens.

关键词： aluminum alloy rare earth conversion film cathodic electrochemicaldeposition

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Corrosion Fatigue Behavior of Duplex Stainless Steel in 3.5% Sodium Chloride Solution

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Journal of University of Science and Technology Beijing 2001年第2期8卷 133-136页

作者： S. H Abubakir, Yinshun Wu, Baofeng Ding, jiuqing li Bei Cao (Material Science and Engineering School, University of Science and Technology Beijing, Beijing 100083, China) Material Sci. and Engineering School University of Science and Technology Beijing 100083 China

The corrosion fatigue behavior of duplex stainless steel (DSS) was studied at different cyclic stress levels in 3.5%NaCl (mass fraction, so as the follows) solution (pH=7) at 50 degreesC. The results showed that DSS was susceptible to pitting corrosion and corrosion fatigue. Both intergranluar corrosion cracking and transgranlular corrosion cracking initiated at the bottom of pitting holes. Furthermore, the corrosion fatigue properties of DSS in 3.5%NaCl solution may be relatived to complex electrochemical and mechanical coupling effects between the three phases (austenite, ferrite and martensite), where martensite and ferrite were anodic in the corrosion cell and could be prone to cracking under certain condition.

关键词： corrosion fatigue duplex stainless steel sodium chloride solution

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Charitable Heart and Rewarding Conduct——Impression from the Reception of the Goodwill Delegation of California

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International Understanding 2003年第4期 37-40页

作者： li Jin Chang jiuqing

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Speech at the 27^(th) Annual Conference of the International Initiatives of Change Association of Japan

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International Understanding 2004年第3期 32-33页

作者： li Yang Chang jiuqing

Today, my colleagues and I feel very happy and honored to be invited to come to the picturesque coastal city Odawara for the first time to attend the 27^th Annual Conference of the Japanese Association of Initiatives of Change(IC). Now, please allow me, on behalf of the Chinese Association For International Understanding to express our heartfelt thanks to you for your kind invitation and warm hospitality.

关键词：第27届中国-日本国际交流协会年会中国国际交流协会经济增长率经济合作市场经济

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Concept, configuration, and application of on-board nanogrids for use in electric vehicles

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Science China(Technological Sciences) 2024年第7期67卷 2053-2073页

作者： ZHAO Bing li Yong WU Fang WAN JiangHu CAI jiuqing YANG HaiTao liU Fang College of Electrical and Information Engineering Hunan UniversityChangsha 410082China Wuhan Second Ship Design and Research Institute Wuhan 430000China School of Automation Central South UniversityChangsha 410083China

Against the backdrop of increasingly serious climate change, researchers are attempting to extend macroscale carbon reduction research to smaller scales. With the rapid development and widespread application of electric vehicles(EVs), an effective approach for carbon reduction based on EVs has the potential to be developed. To coordinate and manage the EV platform in diverse application scenarios, the concept of an on-board nanogrid(OBNG), in which a nanogrid is combined with the EV, is proposed and defined, and the characteristics summarized. A configuration that includes a physical layer with the on-board hardware system;an information layer for logical control, energy management, and communication coordination;and an application layer that can cope with different working environments is proposed. A detailed introduction to the basic architecture and management mode of each layer is provided along with information concerning the relevant technologies for coordinated operation. New ideas and approaches to improve the existing performance are proposed, and finally, combined with a background of smart and low-carbon cities, major application scenarios are envisioned.

关键词： electric vehicle nanogrid energy management hybrid energy storage power electronics converter

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ANALYSIS OF DEPOSITED PRODUCTS AND REANODIZED POROUS LUBRICATING FILM ON A1 AFTER(NH_4)_2MoS_4 SOLUTION TREATMENT

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Acta Metallurgica Sinica(English Letters) 1993年第8期6卷 102-107页

作者： JIANG Guang WU Yinshun li jiuqing liU Haiping University of Science and Technology Beijing,Beijing,China Department of Surface Sciences and Corrosion Engineering,University of Science and Technology Beijing,Beijing 100083,China Beijing Univ of Science and Technology Beijing China

Observation was carried out of the structure of sulphuric,oxalic or phosphoric film on Al after treatment of reanodizing and electrolytic depositing lubricant in (NH_4)_2MoS_4 solution,as well as of the deposited products by means of EMPA,TEM and energy spectro-scopic *** deposited products are mixture of compounds of S and Mo rather than single MoS_2 and most of them dcposited near the surface layer of the *** regular long pores without barrier layer occurred in the film,but the regular fine channels without relation to the structural element parameters of original anodized film were found in the thickened barrier layer of phosphoric *** may be remained as Mo sulphide in the film during heating under Ar protective environment.

关键词： Al anodizing reanodizing lubricating film MoS_2

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镁合金在大气环境中电偶腐蚀行为及规律的研究(英文)

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稀有金属材料与工程 2007年第2期36卷 201-207页

作者：肖葵董超芳李久青李晓刚魏丹北京科技大学材料科学与工程学院中国腐蚀与防护学会北京100083

在北京大气环境下,研究AM60镁合金和不同金属材料(碳钢、不锈钢、黄铜和铝合金)偶接的电偶腐蚀行为规律。研究表明,镁合金作为阳极发生不同程度的电偶腐蚀,通过1a的北京大气环境下的暴露试验后,AM60镁合金的电偶腐蚀效应由强到弱的顺序... 详细信息

在北京大气环境下,研究AM60镁合金和不同金属材料(碳钢、不锈钢、黄铜和铝合金)偶接的电偶腐蚀行为规律。研究表明,镁合金作为阳极发生不同程度的电偶腐蚀,通过1a的北京大气环境下的暴露试验后,AM60镁合金的电偶腐蚀效应由强到弱的顺序为:碳钢、黄铜、不锈钢和铝合金,其中镁合金与LY12铝合金偶接的电偶腐蚀效应最小。通过与其它地区室外暴晒的镁合金电偶腐蚀效应的对比,表明环境因素影响着镁合金的电偶腐蚀效应。同时阴极材料、试验时间、试样尺寸(偶接面积)和试验环境都会对镁合金电偶腐蚀效应产生影响。经1a曝晒的AM60镁合金形成了具有保护性的腐蚀产物层阻碍了腐蚀发展。北京地区高自然降尘量导致金属表面湿润时间加大,从而加速了AM60镁合金的电偶腐蚀。采用XRD方法分析表面的腐蚀产物,用金相显微镜和扫描电镜(SEM)观察试样腐蚀后的表面形貌特征和腐蚀产物的结构,并用与之相连的能谱仪分析腐蚀产物中的元素组成。

关键词：镁合金电偶腐蚀大气腐蚀

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