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Families of hyperelliptic curves with maximal slopes

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Science China Mathematics 2013年第9期56卷 1743-1750页

作者： liu xiaolei TAN ShengLi Department of Mathematics East China Normal University

For each integer g≥2, we construct a family of hyperelliptic curves of genus g whose slope reaches the upper bound obtained by Xiao.

关键词： hyperelliptic curve modular invariant moduli space of curves semistable reduction slope

A continuum thermal stress theory for crystals based on interatomic potentials

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Science China(Physics,Mechanics & Astronomy) 2014年第2期57卷 208-217页

作者： liu xiaolei TANG QiHeng WANG TzuChiang State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of Sciences

This paper presents a new continuum thermal stress theory for crystals based on interatomic *** effect of finite temperature is taken into account via a harmonic *** EAM potential for copper is adopted in this paper and verified by computing the effect of the temperature on the specific heat,coefficient of thermal expansion and lattice *** we calculate the elastic constants of copper at finite *** calculation results are in good agreement with experimental *** thermal stress theory is applied to an anisotropic crystal graphite,in which the Brenner potential is *** dependence of the thermodynamic properties,lattice constants and thermal strains for graphite is *** calculation results are also in good agreement with experimental data.

关键词： thermal stress theory interatomic potential thermal strain finite temperature

Centrifuge experiment on the penetration test for evaluating undrained strength of deep-sea surface soils

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International Journal of Mining Science and Technology 2022年第2期32卷 363-373页

作者： Xingsen Guo Tingkai Nian Wei Zhao Zhongde Gu Chunpeng liu xiaolei liu Yonggang Jia Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering Ocean University of ChinaQingdao 266100China State Key Laboratory of Coastal and Offshore Engineering Dalian University of TechnologyDalian 116024China Department of Civil Environmental and Geomatic EngineeringUniversity College LondonLondon WC1E 6BTUnited Kingdom

Rapid advances in deep-sea mining engineering have created an urgent need for the accurate evaluation of the undrained strength of marine soils,especially surface *** achievements have been made using full-flow penetration penetrometers to evaluate marine soil strength in the deep penetration;however,a method considering the effect of ambient water on the surface penetration needs to be established *** this study,penetrometers with multiple probes were developed and used to conduct centrifuge experiments on South China Sea soil and kaolin ***,the forces on the probes throughout the penetration process were systematically analyzed and ***,the spatial influence zone was determined by capturing the resistance changes and sample crack development,and the penetration depth for a sample to reach a stable failure mode was ***,the vane shear strength was used to invert the penetration resistance factor of the ball and determine the range of the penetration resistance factor ***,a methodology to determine the penetration resistance factors for surface marine soils was ***,the effect of the water cavity above various probes in the surface penetration was used to formulate an internal mechanism for variations in the penetration resistance factor.

关键词： Static penetrometer Centrifuge experiment Deep-sea surface soil Undrained shear strength Penetration resistance factor Water cavity

Modulation of Predator Cue-Evoked Tonic Immobility by Acetylcholine Released in the Basolateral Complex of the Amygdala

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Neuroscience Bulletin 2021年第11期37卷 1599-1604页

作者： Nan liu Kang Huang Pengfei Wei xiaolei liu Liping Wang Shenzhen Key Laboratory of Neuropsychiatric Modulation and Collaborative Innovation Center for Brain Science Guangdong Provincial Key Laboratory of Brain Connectome and BehaviorCAS Center for Excellence in Brain Science and Intelligence TechnologyBrain Cognition and Brain Disease InstituteShenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research InstitutionsShenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen518055China University of the Chinese Academy of Sciences Beijing100049China

Dear Editor,Tonic immobility(TI),also termed"feigning death," is the ultimate defensive response to in escapable *** some predators do not like to eat dead animals.

关键词： threat Release Ton

Combined control of fluid adsorption capacity and initial permeability on coal permeability

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International Journal of Coal Science & Technology 2022年第6期9卷 127-137页

作者： xiaolei liu Jianping Wei Guoying Wei Caifang Wu Cao liu Xiaoming Ni State Key Laboratory Cultivation Base for Gas Geology and Gas Control Henan Polytechnic University454000 JiaozuoHenanChina College of Safety Science and Engineering Henan Polytechnic University454000 JiaozuoHenanChina State Collaborative Innovation Center of Coal Work Safety and Clean-efficiency Utilization 454000 JiaozuoHenanChina Key Laboratory of Coalbed Methane Resource and Reservoir Formation Process Ministry of EducationSouth Jiefang Road221008 XuzhouJiangsuChina Collaborative Innovation Center of Coalbed Methane(Shale Gas)in Central Plains Economic Zone 454000 JiaozuoChina

The variations of strain and permeability of coal were systematically studied through the physical simulation of N2 and water *** effects of fluid adsorption capacity and initial permeability on strain,permeability and the dominant effect of pore pressure were *** adsorption strain and strain rate of coal during water injection are significantly higher than those during N2 *** edge of free adsorption exists in the early phase of N2 and water injection,which is related to fluid *** this boundary,the strain rate and pore pressure are ***,the injec-tion time of initial stage accounts for about 20%of the total injection time,but the strain accounts for 70%of the total *** water injection,this boundary is about half of water saturation of ***,the influence of pore pressure on permeability is complex,which is controlled by adsorption capacity and initial permeability of *** the initial permeability is large enough,the effect of adsorption strain on permeability is relatively weak,and the promoting effect of pore pressure on fluid migration is ***,the permeability increases with increasing pore *** the initial permeability is relatively low,the pore pressure may have a dominant role in promoting fluid migration for the fluid with weak adsorption ***,for the fluid with strong adsorption capacity,the adsorption strain caused by pore pressure may play a leading role,and the permeability reduces first and then ascends with increasing pore pressure.

关键词： Initial permeability Adsorption capacity Free adsorption Pore pressure Coal strain

Classification analysis of prediction skill among ensemble members in MJO subseasonal predictions——based on the results of the CAMS-CSM subseasonal prediction system

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Atmospheric and Oceanic Science Letters 2024年第4期17卷 8-14页

作者： Yihao Peng xiaolei liu Jingzhi Su Xinli liu State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijingChina Center for Earth System Modeling and Prediction of CMA(CEMC) BeijingChina Key Laboratory of Earth System Modeling and Prediction China Meteorological Administration BeijingChina

由于模式误差和初始误差所致,次季节-季节预报技巧整体偏低.国际上多数模式都采用集合预报的方式来提高次季节预报的准确率.热带大气季节内振荡(MJO)作为次季节尺度可预报性的重要来源,其预测水平取决于模式性能和MJO事件本身的物理特性... 详细信息

由于模式误差和初始误差所致,次季节-季节预报技巧整体偏低.国际上多数模式都采用集合预报的方式来提高次季节预报的准确率.热带大气季节内振荡(MJO)作为次季节尺度可预报性的重要来源,其预测水平取决于模式性能和MJO事件本身的物理特性.根据中国气象科学研究院气候系统模式次季节预测系统的回报结果,结合不同类型MJO事件的特征,对模式集合成员间的预报技巧进行了分类和比较.在集合成员预报技巧普遍较高的一类MJO事件中,对流异常信号持续时间较长,强度较大,强对流异常中心主要位于印度洋区域,并逐渐东传至西太平洋.在集合成员预报技巧多数较差的MJO事件中,对流异常信号的强度最弱,维持时间最短.在集合成员预报技巧优劣参半的类别中,MJO往往持续时间较短,强度较低,在后续传播过程中,对流异常中心多停驻在海洋性大陆区域.

关键词：次季节-季节预测预报技巧热带大气季节内振荡

The sound velocity and bulk properties of sediments in the Bohai Sea and the Yellow Sea of China

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Acta Oceanologica Sinica 2016年第7期35卷 76-86页

作者： ZHENG Jiewen liu Baohua KAN guangming LI Guanbao PEI Yanliang liu xiaolei Key Laboratory of Marine Sedimentology and Environmental Geology of State Oceanic Administration State Oceanic Administration Qingdao 266061 China First Institute of Oceanography State Oceanic Administration Qingdao 266061 China Qingdao National Laboratory for Marine Science and Technology Qingdao 266237 China National Deep Sea Center State Oceanic Administration Qingdao 266237 China Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering Ocean University of China Qingdao 266100 China

In order to investigate the correlation between a sound velocity and sediment bulk properties and explore the influence of frequency dependence of the sound velocity on the prediction of the sediment properties by the sound velocity, a compressional wave velocity is measured at frequencies of 25-250 kHz on marine sediment samples collected from the Bohai Sea and the Yellow Sea in laboratory, together with the geotechnical parameters of sediments. The results indicate that the sound velocity ranges from 1.232 to 1.721 km/s for the collected sediment samples with a significant dispersion within the series measuring frequency. Poorly sorted sediments are highly dispersive nearly with a positive linear relationship. The porosity shows a better negative logarithmic correlation with the sound velocity compared with other geotechnical parameters. Generally, the sound velocity increases with the increasing of the average particle size, sand content, wet and dry bulk densities, and decreasing of the clay content, and water content. An important point should be demonstrated that the higher correlation can be obtained when the measuring frequency is low within the frequency ranges from 25 to 250 kHz since the inhomogeneity of sediment properties has a more remarkably influence on the laboratory sound velocity measurement at the high frequency.

关键词： sound velocity particle composition physical properties frequency dispersion empirical equation

Tidal flat erosion of the Huanghe River Delta due to local changes in hydrodynamic conditions

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Acta Oceanologica Sinica 2014年第7期33卷 116-124页

作者： JIA Yonggang ZHENG Jiewen YUE Zhongqi liu xiaolei SHAN Hongxian Key Laboratory of Marine Environment and Ecology Ministry of Education Ocean University of China First Institute of Oceanology State Oceanic Administration Key Laboratory of State Oceanic Administration for Marine Sedimentology and Environmental Geology First Institute of Oceanography State Oceanic Administration Department of Civil Engineering University of Hong Kong

An ideal nature system for the study of post-depositional submarine mass changing under wave loading was selected in the intertidal platform of the subaqueous Huanghe River Delta, a delta formed during period from 1964 to 1976 as the Huanghe River discharged into the Bohai Gulf by Diaokou distributary. A road embankment constructed for petroleum recovery on the inter-tidal platform in 1995 induced the essential varieties of hydrodynamic conditions on the both sides of the road. With both sides sharing similarities in （1） initial sedimentary environment, （2） energetic wave loading, （3） differential hydrodynamic conditions in later stages, （4） enough long-range action, and （5） extreme shallow water inter-tidal platforms; the study is representative and feasible as well. Two study sites were selected on each side of the road, and a series of measurements, samplings, laboratory experiments have been carried out, including morphometry, hydrodynamic conditions, sediment properties, granularity composition, and fractal dimension calculation of the topography in the two adjacent areas. It was observed that in the outer zone, where wave loading with high magnitude prevailed, the tidal flat was bumpy and exhibited a high erosion rate and high fractal dimension. Further, the fractal dimension diminished quickly, keeping with the enlarging of calculative square size. However in the inner zone, where the hydrodynamic condition was weak, the tidal fiat was fiat and exhibited a low erosion rate and low fractal dimensions; the fractal dimension diminished with the enlarging of calcu- lative square size. The fractal dimensions in the different hydrodynamic areas equalized increasingly as the calculative square size accreted to threshold, indicating that the hydrodynamic condition plays a significant role in topography construction and submarine delta erosion process. Additionally, the later differentiation of sediment properties, granularity composition, microstructure characteristi

关键词： hydrodynamic conditions coastal erosion sea-bed topography in-situ measurement fractal calculation

Deep seabed mining:Frontiers in engineering geology and environment

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International Journal of Coal Science & Technology 2023年第2期10卷 1-31页

作者： Xingsen Guo Ning Fan Yihan liu xiaolei liu Zekun Wang Xiaotian Xie Yonggang Jia Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering Ocean University of ChinaQingdao 266100China Department of Civil Environmentaland Geomatic EngineeringUniversity College LondonLondon WC1E 6BTUK College of Civil Engineering and Architecture Wenzhou UniversityWenzhou 325035China Key Laboratory of Engineering and Technology for Soft Soil Foundation and Tideland Reclamation of Zhejiang Province Wenzhou UniversityWenzhou 325035China Laboratory for Marine Geology Qingdao National Laboratory for Marine Science and TechnologyQingdao 266061China

Ocean mining activities have been ongoing for nearly 70 years,making great contributions to *** the increasing demand for energy,along with the restructuring of the energy supply catalyzed by efforts to achieve a low-carbon economy,deep seabed mining will play an important role in addressing energy-and resource-related problems in the ***,deep seabed mining remains in the exploratory stage,with many challenges presented by the high-pressure,low-temperature,and complex geologic and hydrodynamic environments in deep-sea mining areas,which are inaccessible to human ***,considerable efforts are required to ensure sustainable,economic,reliable,and safe deep seabed *** study reviews the latest advances in marine engineering geology and the environment related to deep-sea min-ing activities,presents a bibliometric analysis of the development of ocean mineral resources since the 1950s,summarizes the development,theory,and issues related to techniques for the three stages of ocean mining(i.e.,exploration,extraction,and closure),and discusses the engineering geology environment,geological disasters,in-situ monitoring techniques,envi-ronmental protection requirements,and environmental effects in ***,this paper gives some key conclusions and future perspectives to provide insights for subsequent studies and commercial mining operations.

关键词： Deep seabed mining Marine engineering geology Geological disasters Environment Techniques