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A Rendezvous Mission to the Second Earth Trojan Asteroid 2020 XL_5 with Low-Thrust Multi-Gravity Assist Techniques

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Research in Astronomy and Astrophysics 2024年第1期24卷 245-264页

作者： Shi-hai Yang Bo Xu xin li School of Aeronautics and Astronautics Sun Yat-sen UniversityShenzhen 518107China

As the second of Earth's Trojan asteroids, 2020 XL_(5) is worthy of rendezvous and even sample return missions in many aspects. In this paper, a rendezvous mission to Earth's second Trojan asteroid 2020 XL_(5) is ***, due to its high inclination and large eccentricity, direct impulsive transfer requires large amounts of fuel consumption. To address this challenge, we explore the benefits of electric propulsion and multi-gravity assist techniques for interplanetary missions. These two techniques are integrated in this mission design. The design of a low-thrust gravity-assist(LTGA) trajectory in multi-body dynamics is thoroughly investigated,which is a complex process. A comprehensive framework including three steps is presented here for optimization of LTGA trajectories in multi-body dynamics. The rendezvous mission to 2020 XL_(5) is designed with this three-step approach. The most effective transfer sequence among the outcomes involves Earth–Venus–Earth–Venus-2020 XL_(5). Numerical results indicate that the combination of electric propulsion and multi-gravity assists can greatly reduce the fuel consumption, with fuel consumption of 9.03%, making it a highly favorable choice for this rendezvous mission.

关键词： minor planets asteroids:general celestial mechanics Planetary Systems

Ultrathin porous graphitic carbon nanosheets activated by alkali metal salts for high power density lithium-ion capacitors

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Rare Metals 2020年第12期39卷 1364-1373页

作者： Yu-Qing Dai Guang-Chao li xin-hai li Hua-Jun Guo Zhi-xing Wang Guo-Chun Yan Jie-Xi Wang School of Metallurgy and Environment&College of Chemistry and Chemical Engineering Central South UniversityChangsha410083China Engineering Research Center of the Ministry of Education for Advanced Battery Materials School of Metallurgy and Environment&College of Chemistry and Chemical EngineeringChangsha410083China

Graphitic carbons with reasonable pore volume and appropriate graphitization degree can provide efficient li+/electrolyte-transfer channels and ameliorate the sluggish dynamic behavior of battery-type carbon negative electrode in lithium-ion capacitors(liCs).In this work,onion-like graphitic carbon materials are obtained by using carbon quantum dots as precursors after sintering,and the effects of alkali metal salts on the structure,morphology and performance of the samples are *** results show that alkali metal salts as activator can etch graphitic carbons,and the specific surface area and pore size distribution are intimately related to the description of the alkali metal ***,it also affects the graphitization degree of the *** porous graphitic carbons(SGCs)obtained by NaCl activation exhibit high specific surface area(77.14 m^(2)·g^(-1))and appropriate graphitization *** is expectable that the electrochemical performance for lithium-ions storage can be largely promoted by the smart combination of catalytic graphitization and pores-creating ***-performance liCs(S-GCs//AC liCs)are achieved with high energy density of 92 Wh·kg^(-1)and superior rate capability(66.3 Wh·kg^(-1)at10 A·g^(-1))together with the power density as high as10020.2 W·kg^(-1).

关键词： Alkali metal salts activation Porous graphitic carbons Catalytic graphitization lithium-ion capacitors

Mechanism for capacity fading of 18650 cylindrical lithium ion batteries

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Transactions of Nonferrous Metals Society of China 2017年第7期27卷 1602-1607页

作者： Jian-liang CHENG xin-hai li Zhi-xing WANG Hua-jun GUO School of Metallurgy and Environment Central South University Changsha 410083 China

The mechanism for capacity fading of18650lithium ion full cells under room-temperature(RT)is *** capacity loss of18650cells is about12.91%*** cells after cycles are analyzed by XRD,SEM,EIS and *** measurement shows an overall increase in the cell resistance upon ***,it also presents anincreased charge-transfer resistance(Rct)for the cell cycled at *** test shows that the reversibility of lithium ioninsertion/extraction reaction is *** capacity fading for the cells cycled can be explained by taking into account the repeatedfilm formation over the surface of anode and the side *** products of side reactions deposited on separator are able toreduce the porosity of *** a result,the migration resistance of lithium ion between the cathode and anode would beincreased,leading the fading of capacity and potential.

关键词： 18650 lithium ion battery capacity fading cycle performance

Recovery of valuable metals from lepidolite by atmosphere leaching and kinetics on dissolution of lithium

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Transactions of Nonferrous Metals Society of China 2019年第3期29卷 641-649页

作者： Jin-lian liU Zhou-lan YIN xin-hai li Qi-yang HU Wei liU School of Chemistry and Chemical Engineering Central South University Changsha 410083 China Jiangxi Yunwei New Material Company limited Yichun 336000 China School of Metallurgy and Environment Central South University Changsha 410083 China

The lepidolite located in Yichun, Jiangxi Province, China, was adopted to investigate the recovery of alkali metals and leaching kinetics of lithium with sulphuric acid solution under atmospheric pressure. The results show that the recoveries of alkali metals were achieved under the leaching conditions: mass ratio of lepidolite with particle size less than 180 μm to sulphuric acid 1.2, leaching temperature 411 K, liquid-solid ratio 2.5∶1, and leaching time 10 h. Under the selected conditions for leaching experiment, the leaching rates of lithium, potassium, rubidium and caesium are 94.18%, 93.70%, 91.81% and 89.22%, respectively. The X-ray diffraction analysis for leaching residue indicates that no insoluble product forms during leaching. The chemical compositions of leaching residue reveal that trace iron, manganese and calcium disappear after acid leaching. The kinetics of leaching process for lithium follows shrinking core model of mixed control and the apparent activation energy is 17.21 kJ/mol. The reaction orders with respect to sulphuric acid concentration and liquid-solid ratio are determined to be 2.85 and 1.66, respectively. A semi-empirical rate equation was obtained to describe the leaching process. The kinetic analysis shows that the leaching process is controlled by diffusion through the insoluble layer of the associated minerals.

关键词： kinetics lepidolite lithium activation energy leaching

Review of silicon-based alloys for lithium-ion battery anodes

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International Journal of Minerals,Metallurgy and Materials 2021年第10期28卷 1549-1564页

作者： Zhi-yuan Feng Wen-jie Peng Zhi-xing Wang Hua-jun Guo xin-hai li Guo-chun Yan Jie-xi Wang School of Metallurgy and Environment Central South UniversityChangsha 410083China Engineering Research Center of the Ministry of Education for Advanced Battery Materials Central South UniversityChangsha 410083China Hunan Provincial Key Laboratory of Nonferrous Value-Added Metallurgy Central South UniversityChangsha 410083China

Silicon(Si)is widely considered to be the most attractive candidate anode material for use in next-generation high-energy-density lithium(li)-ion batteries(liBs)because it has a high theoretical gravimetric li storage capacity,relatively low lithiation voltage,and abundant ***,massive efforts have been exerted to improve its electrochemical *** some progress in this field has been achieved,a number of severe challenges,such as the element’s large volume change during cycling,low intrinsic electronic conductivity,and poor rate capacity,have yet to be *** to solve these problems have been attempted via the development of nanosized Si ***,reviews summarizing the work on Si-based alloys are ***,the recent progress related to Si-based alloy anode materials is *** problems associated with Si anodes and the corresponding strategies used to address these problems are first ***,the available Si-based alloys are divided into Si/li-active and inactive systems,and the characteristics of these systems are *** special systems are also ***,perspectives and future outlooks are provided to enable the wider application of Si-alloy anodes to commercial liBs.

关键词： silicon alloy anode lithium-ion battery

Enhanced cycling stability of La modified liNi_(0.8-x)Co_(0.1)Mn_(0.1)La_xO_2 for li-ion battery

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Transactions of Nonferrous Metals Society of China 2017年第5期27卷 1134-1142页

作者： Ming-xia DONG Xiang-qun li Zhi-xing WANG xin-hai li Hua-jun GUO Zhen-jun HUANG School of Metallurgy and Environment Central South University Changsha 410083 China

A series of layered liNi0.8?xCo0.1Mn0.1LaxO2(x=0,0.01,0.03)cathode materials were synthesized by combining co-precipitation and high temperature solid state reaction to investigate the effect of La-doping on liNi0.8Co0.1Mn0.1O2.A new phase La2li0.5Co0.5O4was observed by XRD,and the content of the new phase could be determined by Retiveld refinement and *** cycle stability of the material is obviously increased from74.3%to95.2%after La-doping,while the initial capacity exhibits a decline trend from202mA·h/g to192mA·h/*** enhanced cycle stability comes from both of the decrease of impurity and the protection of newly formed La2li0.5Co0.5O4,which prevents the electrolytic corrosion to the active *** CV measurement confirms that La-doped material exhibits better reversibility compared with the pristine material.

关键词： nickel-rich cathode material La-doping electrochemical property cycle stability li-ion diffusion coefficient

High-temperature wetting behavior between slag and refractory

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Journal of Iron and Steel Research International 2024年第6期31卷 1304-1319页

作者： Yong-xin Wang Ya-ge li Ya-bo Gao Zhong Huang hai-jun Zhang The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina

Slag corrosion is one of the main factors of the damage of refractory,and its primary manifestations involve the melting of refractory in slag and the slag penetration into refractory,both of which are highly related to the wetting behavior between slag and *** high-temperature wettability could be characterized by parameters including the surface tension,adhesion work,and spreading coefficient of the slag on refractory surface,and it could be suppressed by altering the slag/refractory interface,thus resulting in an improved anti-corrosion *** this,the key knowledges of the slag corrosion,theory of wetting behavior and test of high-temperature contact angle were firstly ***,the major factors influencing the high-temperature slag wetting behavior were discussed based on the aspects of slag composition,refractory composition,and surface ***,the future research direction was proposed in this field.

关键词： High-temperature wetting Refractory Slag corrosion Surface tension

Hydrogen storage thermodynamics and kinetics of as-cast Ce-Mg-Ni-based alloy

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Journal of Iron and Steel Research International 2024年第3期31卷 752-766页

作者： Yan Qi xin Zhang Jun li Dong-liang Zhao Shi-hai Guo Yang-huan Zhang Department of Functional Material Research Central Iron and Steel Research InstituteBeijing 100081China China Rare Earth New Material(Weishan)Co..Ltd. Jining 277600ShandongChina Collaborative Innovation Center of Integrated Exploitation of Bayan Obo Multi-Metal Resources Inner Mongolia University of Science and TechnologyBaotou 014010Inner MongoliaChina

The reaction kinetics of alloys based on magnesium are known to be greatly improved by the partial substitution of Mg with rare earths and transition metals,particularly *** enhanced superficial hydrogen dissociation rate,the weakened Mg-H bond and the lower activation energy following element replacement are thought to be related to the better *** experimental alloys Ce5Mg_(95-x)Ni_(x)(x=5,10,15)were smelted by the vacuum induction *** phase transformation and structural evolution of experimental alloys before and after reaction with hydrogen were char-acterized by X-ray diffraction,scanning electron microscopy and transmission electron *** cast specimens contain CeMg_(12),Mg and Mg_(2)Ni phases,and the increase in Ni content results in an obvious growth of Mg_(2)Ni *** isothermal and non-isothermal hydrogenation and dehydrogenation kinetics of the experimental specimens were investi-gated using the Sievert apparatus,differential scanning calorimetry and thermal gravimetric *** activation energy may be calculated using the Arrhenius and Kissinger *** experimental alloys have been shown to have good activation properties,with a reversible hydriding and dehydriding capacities of around 5.0 wt.%in the first *** initial dehydrogenation temperature of MgH_(2) decreases from 557.5 to 537.7 K with changing Ni content from 5 to 15 at.%.The dehydrogenation activation energy also reduces from 77.09 to 62.96 kJ/mol,which explains the improved hydrogen storage performance caused by Ni *** can be shown that the impact of Ni on the decomposition enthalpy of MgH_(2) is quite modest,with the absolute enthalpy(ΔHr)only decreasing from 78.48 to 76.15 kJ/mol.

关键词： Mg-based alloy Ni content Hydrogen storage kinetics Thermodynamic property Activation energy

Facile preparation of Fe/N-based biomass porous carbon composite towards enhancing the thermal decomposition of DAP-4

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Defence Technology（防务技术） 2024年第1期31卷 288-294页

作者： Er-hai An Xiao-xia li Cun-juan Yu Ying-xin Tan Zi-jun Fan Qing-xia li Peng Deng Xiong Cao School of Environment and Safety Engineering North University of ChinaTaiyuan030051PR China College of Safety and Emergency Management Engineering Taiyuan University of Science and TechnologyTaiyuan030024PR China

Fe/N-based biomass porous carbon composite(Fe/N-p Carbon) was prepared by a facile high-temperature carbonization method from biomass,and the effect of Fe/N-p Carbon on the thermal decomposition of energetic molecular perovskite-based material DAP-4 was *** porous carbonaceous materials was considered as the micro/nano support layers for in situ deposition of Fe/N ***/Np Carbon was prepared simply by the high-temperature carbonization *** was found that it showed the inherent catalysis properties for thermal decomposition of *** heat release of DAP-4/Fe/N-p Carbon by DSC curves tested had increased slightly,compared from DAP-4/Fe/N-p *** decomposition temperature peak of DAP-4 at the presence of Fe/N-p Carbon had reduced by 79°C from384.4°C(pure DAP-4) to 305.4°C(DAP-4/Fe/N-p Carbon-3).The apparent activation energy of DAP-4thermal decomposition also had decreased by 29.1 J/*** possible catalytic decomposition mechanism of DAP-4 with Fe/N-p Carbon was proposed.

关键词： Biomass materials Porous carbon DAP-4 Thermal decomposition Facile method