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extreme Sports

ChinAfrica 2024年第8期16卷 58-59页

作者： KANG CHENYI ATHIEI AJUONG 不详

The Double Take column looks at a single topic from an African and Chinese *** month we discuss whether it is worthwhile to engage in extreme sports.

关键词： extreme extreme sports

extreme Temperature Change of the Last 110 Years in Changchun,Northeast China

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Advances in Atmospheric Sciences 2020年第4期37卷 347-358,I0002-I0006页

作者： Xiujing YU Guoyu REN Panfeng ZHANG Jingbiao HU Ning LIU Jianping LI Chenchen ZHANG Jilin Climate Center Changchun 130062China Department of Atmospheric Science School of Environmental StudiesChina University of GeosciencesWuhan 430074China Laboratory for Climate Studies National Climate CenterChina Meteorological AdministrationBeijing 100081China Jilin Province Weather Modification Office Changchun 130062China Institute of Meteorological Sciences of Jilin Province Changchun 130062China

In China and East Asia,the long-term continuous observational data at daily resolution are insufficient,and thus there is a lack of good understanding of the extreme climate variation over the last 100 years *** this study,the extreme temperature indices defined by ETCCDI(Expert Team on Climate Change Detection and Indices)and local meteorological administrations were analyzed for Changchun City,Northeast China,by using the daily maximum temperature(Tmax)and daily minimum temperature(Tmin)over 1909?*** results showed that extreme cold events,such as cold days,cold nights,frost days,icing days,and low temperature days,decreased significantly at rates of?0.41 d(10 yr)^?1,?1.45 d(10 yr)^?1,?2.28 d(10 yr)^?1,?1.16 d(10 yr)?1 and?1.90 d(10 yr)^?1,*** nights increased significantly at a rate of 1.71 d(10 yr)^?1,but warm days decreased slightly and the number of high temperature days decreased at a rate of?0.20 d(10 yr)?*** frequency of cold surge events increased significantly at a rate of 0.25 d(10 yr)^?1,occurring mainly from the mid-1950s to *** average Tmax,average Tmin and extreme Tmin increased at rates of 0.09℃(10 yr)^?1,0.36℃(10 yr)^?1 and 0.54℃(10 yr)^?1,respectively;and extreme Tmax decreased significantly at a rate of?0.17℃(10 yr)^?*** 1909?2018,1951?2018 and 1979?2018,the indices related to cold events decreased,while the trends of the indices related to warm events were different for different periods.

关键词： extreme temperature climate change long-term series observation Changchun Northeast China

extreme Sea Level Rise off the Northwest Coast of the South China Sea in 2012

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Journal of Ocean University of China 2018年第5期17卷 991-999页

作者： LIU Lin LI Juan TAN Wei WU Yue LIU Yanliang WANG Huiwu Center for Ocean and Climate Research First Institute of OceanographyState Oceanic Administration Laboratory for Regional Oceanography and Numerical Modeling Qingdao National Laboratory for Marine Science and Technology Laboratory of Marine Science and Numerical Modeling First Institute of OceanographyState Oceanic Administration

Tide gauge data are used to investigate sea level variability offthe northwest coast of the South China Sea （SCS） in 2012, and a significant sea level elevation with a magnitude approaching 79 mm is observed. Analysis suggests that an abnormal sea surface heat flux and freshwater flux may have contributed to this abnormal rise in sea level, together with the remote influence of an ENSO event. Further investigation shows that the event was dominated by the positive freshwater flux, where large volumes of water entered the ocean, and a maximum is centered to the south of Guangdong province, China. Simultaneously, a positive anomalous heat flux occurred in the northwestern part of the SCS, which is considered to have made a positive contribution to the high local sea level elevation. In addition to the heat flux, the ENSO event also had a significant effect on the event, where the La Nifia-induced northwest Pacific cyclone contributed to sea level rise over the northwestern SCS through dynamic and thermodynamic interactions.

关键词： sea level rise South China Sea interannual variability extreme

baogai:extreme makeover

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China Weekly 2024年第8期 64-64页

Facing the economic slowdown,China's leading supermarket operator Yonghui partnered with Pangdonglai,a supermarket brand known for its highquality services,to revamp one of its stores in Zhengzhou,Central China's Hena... 详细信息

关键词： extreme Province. operator

A soft sensor for industrial melt index prediction based on evolutionary extreme learning machine

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Chinese Journal of Chemical Engineering 2016年第8期24卷 1013-1019页

作者： Miao Zhang Xinggao Liu Zeyin Zhang State Key Laboratory of Industrial Control Technology Department of Control Science and Engineering Zhejiang University Department of Mathematics Zhejiang University

In propylene polymerization(PP) process, the melt index(MI) is one of the most important quality variables for determining different brands of products and different grades of product quality. Accurate prediction of MI is essential for efficient and professional monitoring and control of practical PP processes. This paper presents a novel soft sensor based on extreme learning machine(ELM) and modified gravitational search algorithm(MGSA) to estimate MI from real PP process variables, where the MGSA algorithm is developed to find the best parameters of input weights and hidden biases for ELM. As the comparative basis, the models of ELM, APSO-ELM and GSAELM are also developed respectively. Based on the data from a real PP production plant, a detailed comparison of the models is carried out. The research results show the accuracy and universality of the proposed model and it can be a powerful tool for online MI prediction.

关键词： Propylene polymerization Melt index prediction extreme learning machine Gravitational search algorithm

extreme biomimetic approach for developing novel chitin-GeO2 nanocomposites with photoluminescent properties

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Nano Research 2015年第7期8卷 2288-2301页

作者： Marcin Wysokowski Mykhailo Motylenko Jan Beyer Anna Makarova Hartmut Stocker Juliane Walter Roberta Galli Sabine Kaiser Denis Vyalikh Vasilii V. Bazhenov laroslav Petrenko Allison L Stelling Serguei L. Molodtsovs Dawid Stawski Krzysztof J.Kurzydfowski Enrico Langer Mikhail V Tsurkan Teofil Jesionowski Johannes Heitmann Dirk C. Meyer Hermann Ehrlich Institute of Chemical Technology and Engineering Poznan University of Technology 60965 Poznan Poland Institute of Materials Science TU Bergakademie Freiberg 09599 Freiberg Germany Institute of Applied Physics TU Bergakademie Freiberg 09599 Freiberg Germany Institute of Solid State Physics Dresden University of Technology 01069 Dresden Germany Institute of Experimental Physics TU Bergakademie Freiberg 09599 Freiberg Germany Faculty of Medicine Carl Gustav Carus Department of Anaesthesiology and Intensive Care Medicine Clinical Sensoring and Monitoring TU Dresden 01069 Dresden Germany epartment of Physics St. Petersburg State University 198504 St. Petersburg Russia Department of Mechanical Engineering and Materials Science Duke University 27708 Durham NC USA European X-Ray Free-Electron Laser Facility (XFEL) GmbH 22761 Hamburg Germany ITMO University 197101 St. Petersburg Russia Department of Commodity and Material Sciences and Textile Metrology Technical University of Lodz 90924 LSdz Poland Materials Design Group Faculty of Materials Science and Engineering Warsaw University of Technology PL-02507 Warsaw Poland Institute of Semiconductors and Microsystems TU Dresden 01062 Dresden Germany Leibniz Institute of Polymer Research Max Bergmann Centre for Biomaterials 01062 Dresden Germany

This work presents an extreme biomimetics route for the creation of nano- structured biocomposites utilizing a chitinous template of poriferan origin. The specific thermal stability of the nanostructured chitinous template allowed for the formation under hydrothermal conditions of a novel germanium oxide- chitin composite with a defined nanoscale structure. Using a variety of analytical techniques （FTIR, Raman, energy dispersive X-ray （EDX）, near-edge X-ray absorption fine structure （NEXAFS）, and photoluminescence （PL） spectroscopy, EDS-mapping, selected area for the electron diffraction pattern （SAEDP）, and transmission electron microscopy （TEM））, we showed that this bioorganic scaffold induces the growth of GeO2 nanocrystals with a narrow （150-300 nm） size distri- bution and predominantly hexagonal phase, demonstrating the chitin template＇s control over the crystal morphology. The formed GeO2-chitin composite showed several specific physical properties, such as a striking enhancement in photo- luminescence exceeding values previously reported in GeOR-based biomaterials. These data demonstrate the potential of extreme biomimetics for developing new-generation nanostructured materials.

关键词： extreme biomimetics, chitin-GeO2 photoluminescence, near-edge X-ray absorption fine structure (NEXAFS) spectroscopy

Oil-soluble ionic liquids as antiwear and extreme pressure additives in poly-α-olefin for steel/steel contacts

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Friction 2019年第1期7卷 18-31页

作者： Guowei HUANG Qiangliang YU Zhengfeng MA Meirong CAI Feng ZHOU Weimin LIU State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical Physics Chinese Academy of Sciences University of Chinese Academy of Sciences

To enhance the lubricating and extreme pressure(EP) performance of base oils, two types of oil-soluble ionic liquids(ILs) with similar anion albeit dissimilar cations were synthesized. The physical properties of the prepared ILs were measured. The anticorrosion properties of ILs were assessed by conducting corrosion tests on steel discs and copper strips, which revealed the remarkable anticorrosion properties of the ILs in comparison with those of the commercial additive zinc dialkyldithiophosphate(ZDDP). The tribological properties of the two ILs as additives for poly-α-olefin-10(PAO10) with various mass concentrations were investigated. The tribological test results indicate that these ILs as additives are capable of reducing friction and wear of sliding contacts remarkably as well as enhance the EP performance of blank PAO10. Under similar test conditions, these IL additives exhibit higher lubricating and anti-wear(AW) performances than those of ZDDP based additive package in PAO10. Subsequently, X-ray photoelectron spectroscopy(XPS) and energy dispersive spectrometer(EDS) were conducted to study the lubricating mechanism of the two ILs. The results indicate that the formation of tribochemical film plays the most crucial role in enhancing the lubricating and AW behavior of the mixture lubricants.

关键词： anti-wear extreme pressure ionic liquids lubricating mechanism

extreme learning-based non-linear model predictive controller for an autonomous underwater vehicle:simulation and experimental results

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IET Cyber-Systems and Robotics 2019年第2期1卷 45-54页

作者： Biranchi Narayan Rath Bidyadhar Subudhi Department of Electrical Engineering National Institute of Technology RourkelaRourkela 769008India School of Electrical Sciences Indian Institute of Technology GoaPondaGoa-401403India

In this study,an extreme learning-based non-linear model predictive controller(NMPC)is proposed for path following planning of an autonomous underwater vehicle(AUV)using horizontal *** proposed controller comprises a kinematic controller and a dynamic *** kinematic controller is designed by using back-stepping approach whilst the dynamic controller is designed by employing the NMPC *** dynamics of the AUV is identified in real-time by employing an extreme learning machine(ELM)*** view of achieving improved performance of the ELM structure,its hidden layer parameters are optimally determined by applying Jaya optimisation *** resulting ELM model is then used to design a NMPC considering the constraint on rudder *** tracking performance of the proposed controller is compared with that of two recently reported control algorithms namely,H∞state feedback controller and inverse optimal self-tuning proportional-integral-derivative(PID)*** proposed controller is implemented using MATLAB and then in real-time on a prototype AUV developed in the authors’*** both the simulation and experimental results obtained,it is observed that the proposed controller exhibits superior tracking performance compared to both H∞state feedback controller and inverse optimal self-tuning PID controller.

关键词： extreme underwater autonomous

Computational screening of materials with extreme gap deformation potentials

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npj Computational Materials 2022年第1期8卷 1482-1491页

作者： Pedro Borlido Jonathan Schmidt Hai-Chen Wang Silvana Botti Miguel A.L.Marques Institut für Festkörpertheorie und-optik Friedrich-Schiller-Universität Jena and European Theoretical Spectroscopy FacilityMax-Wien-Platz 107743JenaGermany CFisUC Department of PhysicsUniversity of CoimbraRua Larga3004-516CoimbraPortugal Institut für Physik Martin-Luther-Universität Halle-WittenbergD-06099HalleGermany

In this work,we present a large-scale study of gap deformation potentials based on density-functional theory calculations for over 5000 *** expected,in most cases the band gap decreases for increasing volume with deformation potentials that can reach values of almost−15 *** find,however,also a sizeable number of materials with positive deformation *** members of this group are halide perovskites,known for their applications in *** then focus on understanding the physical reasons for so different values of the deformation potentials by investigating the correlations between this property and a large number of other material and compositional *** also train explainable machine learning models as well as graph convolutional networks to predict deformation potentials and establish simple rules to understand predicted ***,we analyze in more detail a series of materials that have record positive and negative deformation potentials.

关键词： deformation properties. extreme