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Phase selection and microstructure evolution within eutectic Ti-Si alloy solidified at containerless state

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Science China(Technological Sciences) 2022年第7期65卷 1587-1598页

作者： LUO zhicong CHANG Jian WANG HaiPeng School of Physical Science and Technology Northwestern Polytechnical UniversityXi'an 710072China

Phase selection and microstructure evolution of the undercooled eutectic Ti-Si alloy were systematically investigated by the electromagnetic levitation method, and the maximum undercooling achieved was 318 K(0.2 TE). The migration of the liquidsolid interface was in-situ detected by a high-speed camera system. When the undercooling is smaller than 140 K, the liquid-solid interface is smooth. Once the undercooling arrives at 230 K, the liquid-solid interface is irregular, which reflects the growth transition from the solute control to the combined controls of solute and thermal. The eutectic growth velocity increases as an exponential function of undercooling. The electromagnetic stirring effect makes it difficult to increase undercooling, but plays an important role in accelerating the eutectic reaction velocity at low and moderate undercoolings. Primary dendritic β-Ti phase appears in the solidified alloy from 63 to 176 K undercoolings, and the microstructure is completely composed of eutectic once the undercoolings increase up to 230 K. When the undercoolings exceed 273 K, the microstructure consists of uniformly distributed irregular eutectic. For the drop tube experiments, the microstructures composed of a large amount of dendritic α-Ti phase and eutectic phase are found in a wide range of diameters from 69 to 725 μm. As the decrease of diameter, the solubility of Si in the dendritic α-Ti phase dramatically increases from 6.80% to 10.73%, and the ratio of the area occupied by the dendritic α-Ti on a cross-section of solidified alloy obviously increases from 23.52% to 41.02%, which result from the combined effects of high undercooling and large cooling rate.

关键词： phase selection microstructure evolution high undercooling containerless large cooling rate

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Improving Li Plating Behaviors Through Cu-Sn Alloy-Coated Current Collector for Dendrite-Free Lithium Metal Anodes

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Acta Metallurgica Sinica(English Letters) 2021年第3期34卷 354-358页

作者： Yifeng Cheng Xi Ke zhicong Shi Smart Energy Research Centre School of Materials and EnergyGuangdong University of TechnologyGuangzhou 510006China Guangdong Engineering Technology Research Center for New Energy Materials and Devices Guangzhou 510006China

Alloy anode with good reversibility of lithium plating/stripping and long cycling stability is considered as promising anode ***,Cu-Sn alloy is used as the substrate for Li deposition to induce the most densely packed arrangement of Li atoms,thus presenting high lithiophilicity and improving Li plating *** LiFePO4-based full cell with the asprepared dendrite-free Li metal anode retained at 85 mAh g-1 with a high coulombic efficiency of 99.5% after 300 cycles,presenting a capacity retention of 79.4%.This strategy provides a new perspective to structure dendrite-free Li anode for the next-generation high-energy density batteries.

关键词： Li metal anodes Dendrite-free Composite electrode Lithiophilic surface

Impacts of the SSTs over Equatorial Central–Eastern Pacific and Southeastern Indian Ocean on the Cold and Rainy/Snowy/Icy Weather in Southern China

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Journal of Meteorological Research 2023年第2期37卷 248-261页

作者： Zhuolei QIAN Jiehua MA zhicong YIN Shaoxing Meteorological Office Shaoxing312000 Key Laboratory of Meteorological Disaster(KLME) Ministry of Education&Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)Nanjing University of Information Science&TechnologyNanjing210044 Climate Change Research Center Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing100029 Nansen–Zhu International Research Centre Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing100029 Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai519000

Low temperature together with snow/freezing rain is disastrous in winter over southern *** studies suggest that this is related to the sea surface temperature(SST)anomalies,especially La Nina conditions,over the equatorial central–eastern Pacific Ocean(EP).In reality,however,La Nina episodes are not always accompanied by rainy/snowy/icy(CRSI)da.s in southern China,such as the case in winter 2020/*** there any other factor that works jointly with the EP SST to affect the winter CRSI weather in southern China?To address this question,CRSI da.s are defined and calculated based on station observation da.a,and the related SST anomalies and atmospheric circulations are examined based on the Hadley Centre SST da.a and the NCEP/NCAR reanalysis da.a for winters of1978/1979–2017/*** results indicate that the CRSI weather with more CRSI da.s is featured with both decreased temperature and increased winter precipitation over southern *** SSTs over both the EP and the southeastern Indian Ocean(SIO)are closely related to the CRSI da.s in southern China with correlation coefficients of-0.29 and 0.39,significant at the 90%and 95%confidence levels,*** SST over EP affects significantly air temperature,as revealed by previous studies,with cooler EP closely related to the deepened East Asian trough,which benefits stronger East Asian winter monsoon(EAWM)and lower air temperature in southern ***,this paper discovers that the SST over SIO affects precipitation of southern China,with a correlation coefficient of 0.42,significant at the 99%confidence level,with warmer SIO correlated with deepened southern branch trough(SBT)and strengthened western North Pacific anomalous anticyclone(WNPAC),favoring more water vapor convergence and enhanced precipitation in southern *** presence of La Ni?a in both winters,compared to the winter of 2020/2021,the winter of 2021/2022 witnessed more CRSI da.s,perhaps due to the warmer SIO.

关键词： the cold and rainy/snowy/icy(CRSI)da.s sea surface temperature(SST)anomalies equatorial central–eastern Pacific Ocean(EP) southeastern Indian Ocean(SIO)

Control of friction oscillator by Lyapunov redesign based on delayed state feedback

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Acta Mechanica Sinica 2009年第2期25卷 257-264页

作者： zhicong Li Qi Wang Haiping Gao School of Science Beihang UniversityBeijing 100083 China School of Science Hebei University of Science and TechnologyShijiazhuang 050018 China

The stability and boundedness of mechanical system have been one of important research topics. In this paper ultimate boundedness of a dry friction oscillator, belonging to nonsmooth mechanical system, is investigated by proposing a controller design method. Firstly a sufficient condition of the stability for the nominal system with delayed state feedback is derived by constructing a Lyapunov-Krasovskii function. The delayed feedback gain matrix is calculated by applying linear matrix inequality method. Secondly on the basis of the delayed state feedback, a continuous function is designed by Lyapunov redesign to ensure that the solutions of the friction oscillator system are ultimately bounded under the overall control. Moreover, the ultimate bound can be adjusted in practice by choosing appropriate parameter. Accordingly friction-induced vibration or instability can be controlled effectively. Numerical results show that the pro- posed method is valid.

关键词： Time-delay Nonsmooth system Linear matrix inequality (LMI) Dry friction oscillator Ultimate boundedness

Meteorological influences on co-occurrence of O_(3) and PM_(2.5)pollution and implication for emission reductions in Beijing-Tianjin-Hebei

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Science China Earth Sciences 2023年第6期66卷 1258-1267页

作者： Xiaoqing MA zhicong YIN Bufan CAO Huijun WANG Key Laboratory of Meteorological Disaster Ministry of Education/Joint International Research Laboratory of Climate and Environment Change(ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)Nanjing University of Information Science&TechnologyNanjing 210044China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519080China Nansen-Zhu International Research Centre Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China

Co-occurrence of surface ozone(O_(3))and fine particulate matter(PM_(2.5))pollution(CP)was frequently observed in Beijing-Tianjin-Hebei(BTH).More than 50%of CP da.s occurred during April-May in BTH,and the CP da.s reached up to 11 in two months of *** PM_(2.5)or O_(3) concentration associated with CP was lower than but close to that in O_(3) and PM_(2.5)pollution,indicating compound harms during CP da.s with double-high concentrations of PM_(2.5)and O_(3).CP da.s were significantly facilitated by joint effects of the Rossby wave train that consisted of two centers associated with the Scandinavia pattern and one center over North China as well as a hot,wet,and stagnant environmental condition in *** 2018,the number of CP da.s decreased sharply while the meteorological conditions did not change ***,changes in meteorological conditions did not really contribute to the decline of CP da.s in 2019 and *** implies that the reduction of PM_(2.5)emission has resulted in a reduction of CP da.s(about 11 da.s in 2019 and 2020).The differences in atmospheric conditions revealed here were helpful to forecast the types of air pollution on a da.ly to weekly time *** reduction in PM_(2.5)emission was the main driving factor behind the absence of CP da.s in 2020,but the control of surface O_(3) must be stricter and deeper.

关键词： Co-occurrence pollution Ozone PM_(2.5) Meteorology Emission reduction

A review of deep learning approach to predicting the state of health and state of charge of lithium-ion batteries

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Journal of Energy Chemistry 2022年第11期31卷 159-173,I0006页

作者： Kai Luo Xiang Chen Huiru Zheng zhicong Shi School of Materials and Energy Guangdong University of TechnologyGuangzhou 510006GuangdongChina Department of Chemical Engineering Tsinghua UniversityBeijing 100084China School of Computing Ulster UniversityBelfast BT151EDUnited Kingdom

In the field of energy storage,it is very important to predict the state of charge and the state of health of lithium-ion *** this paper,we review the current widely used equivalent circuit and electrochemical models for battery state *** review demonstrates that machine learning and deep learning approaches can be used to construct fast and accurate da.a-driven models for the prediction of battery *** details,advantages,and limitations of these approaches are presented,compared,and ***,future key challenges and opportunities are discussed.

关键词： Lithium-ion battery State of health State of charge Remaining useful life da.a-driven

Why super sandstorm 2021 in North China?

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National Science Review 2022年第3期9卷 119-127页

作者： zhicong Yin Yu Wan Yijia Zhang Huijun Wang Key Laboratory of Meteorological Disaster Ministry of EducationJoint International Research Laboratory of Climate and Environment Change(ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD)Nanjing University of Information Science and Technology Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) Nansen-Zhu International Research Centre Institute of Atmospheric PhysicsChinese Academy of Sciences

Severe sandstorms reoccurred in the spring of 2021 after an absence for more than 10 years in North *** dust source area,located in Mongolia,suffered destructive cooling and warming in early and late winter,which loosened the land.A lack of precipitation,excessive snow melt and strong evaporation resulted in dry soil and exiguous spring vegetation.A super-strong Mongolian cyclone developed on the bare and loose ground,and easily blew and transported large amounts of sand particles into North ***,top-ranking anomalies(sea ice shift in the Barents and Kara Sea,and sea surface temperatures in the east Pacific and northwest Atlantic) were found to induce the aforementioned tremendous climate anomalies in the dust source *** es,based on large-ensemble Coupled Model Intercomparison Project Phase 6,yield results identical to the reanalysis ***,the climate variabilities at different latitudes and synoptic disturbances jointly facilitated the strongest spring sandstorm over the last decade.

关键词： sandstorm dust source Arctic sea ice La Niña cyclone

Monthly Variations of Atmospheric Circulations Associated with Haze Pollution in the Yangtze River Delta and North China

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Advances in Atmospheric Sciences 2021年第4期38卷 569-580页

作者： Xinyu ZHANG zhicong YIN Huijun WANG Mingkeng DUAN Key Laboratory of Meteorological Disaster Ministry of Education/Joint International Research Laboratory of Climate and Environment Change/Collaborative Innovation Center on Forecast and Evaluation of Meteorological DisastersNanjing University of Information Science and TechnologyNanjing 210044China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519080China Nansen-Zhu International Research Centre Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China

Haze pollution in early winter(December and January) in the Yangtze River Delta(YRD) and in North China(NC)are both severe;however, their monthly variations are significantly different. In this study, the dominant large-scale atmospheric circulations and local meteorological conditions were investigated and compared over the YRD and NC in each month. Results showed that the YRD(NC) is dominated by the so-called Scandinavia(East Atlantic/West Russia)pattern in December, and these circulations weaken in January. The East Asian December and January monsoons over the YRD and NC have negative correlations with the number of haze da.s. The local descending motion facilitates less removal of haze pollution over the YRD, while the local ascending motion facilitates less removal of haze pollution over NC in January, despite a weaker relationship in December. Additionally, the monthly variations of atmospheric circulations showed that adverse meteorological conditions restrict the vertical(horizontal) dispersion of haze pollution in December(January) over the YRD, while the associated local weather conditions are similar in these two months over NC.

关键词： monthly haze pollution atmospheric circulations Yangtze River Delta North China

Energy Optimization Oriented Three-Way Clustering Algorithm for Cloud Tasks

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Journal of Beijing Institute of Technology 2018年第2期27卷 189-197页

作者： Chunmao Jiang Yibing Li zhicong Li Information and Communication Engineering School Harbin Engineering University Computer Science and Information Engineering School Harbin Normal University

Cloud computing has developed as an important information technology paradigm which can provide on-demand services. Meanwhile,its energy consumption problem has attracted a grow-ing attention both from academic and industrial communities. In this paper,from the perspective of cloud tasks,the relationship between cloud tasks and cloud platform energy consumption is established and analyzed on the basis of the multidimensional attributes of cloud tasks. Furthermore,a three-way clustering algorithm of cloud tasks is proposed for saving energy. In the algorithm,f irst,t he cloud tasks are classified into three categories according to the content properties of the cloud tasks and resources respectively. Next,cloud tasks and cloud resources are clustered according to their computation characteristics（ e. g. computation-intensive,da.a-intensive）. Subsequently,greedy scheduling is performed. The simulation results showthat the proposed algorithm can significantly reduce the energy cost and improve resources utilization,compared with the general greedy scheduling algorithm.

关键词： cloud computing cloud energy three-way cluster task attributes