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The Essential 2-rank for Classical Groups

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Acta Mathematica Sinica,English Series 2024年第9期40卷 2169-2186页

作者： Jian Bei AN yong XU Department of Mathematics University of AucklandAucklandNew Zealand School of Mathematics and Statistics He’nan University of Science and TechnologyLuoyang 471023P.R.China

Let G be a symplectic or orthogonal group defined over a finite field with odd characteristic and let D≤G be a Sylow *** this paper,we classify the essential 2-subgroups and determine the essential 2-rank of the Frobenius category FD(G).Together with the results of An–Dietrich and Cao–An–Zeng,this completes the work of essential subgroups and essential ranks of classical groups.

关键词： Frobenius category conjugation families essential 2-rank symplectic groups orthogonal groups

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北京北天堂地区城市垃圾填埋对地下水的污染

水文地质工程地质 2002年第6期29卷 45-47,63页

作者：王翊虹赵勇胜北京市地质工程勘察院环境工程研究所北京100037 吉林大学环境与资源学院长春130026

本文介绍了由于城市垃圾填埋而引起的地下水资源污染问题。以北京南部北天堂垃圾填埋场的污染状况为例进行调查 ,对其进行污染综合评价 ,通过建立数学模型模拟污染物在几种条件下的地下运移情况及补救效果 ,对污染控制进行了模拟。

关键词：北京城市垃圾填埋地下水垃圾填埋场预测模型污染控制

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海面连续溢油的三维实时绘制(英文)

系统仿真学报 2008年第19期20卷 5117-5120页

作者：任鸿翔张新宇尹勇浙江大学CAD&CG国家重点实验室浙江杭州310027 大连海事大学航海动态仿真与控制实验室辽宁大连116026

对短时间尺度内的连续溢油进行研究。海面采用同心圆网格模型模拟,海浪高度图采用快速傅立叶变换方法生成。提出利用平面折射技术实现海面油膜的绘制,采用粒子系统实现油粒子模型,粒子所在位置的潮流速度采用分区方法高效计算。模拟试... 详细信息

对短时间尺度内的连续溢油进行研究。海面采用同心圆网格模型模拟,海浪高度图采用快速傅立叶变换方法生成。提出利用平面折射技术实现海面油膜的绘制,采用粒子系统实现油粒子模型,粒子所在位置的潮流速度采用分区方法高效计算。模拟试验表明,该方法可实现海面连续溢油的逼真、快速模拟。

关键词：连续溢油三维实时绘制海面模拟平面折射

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论程序化的宪法

学习与探索 2002年第2期 32-36页

作者：孙笑侠应永宏浙江大学法学院浙江杭州310000 温州大学人文政法学院浙江温州325000

宪法程序是宪法实施的途径和方法 ,是使宪法有实效的最关键的问题。它包括正当程序原则、国家权力运行程序和合宪性监督程序、立宪程序等内容。其中合宪性监督程序 (又称违宪审查程序或宪法解释程序 )几乎与宪法具有同等的重要性。

关键词：宪法宪法程序国家权力运行程序合宪法监督程序

四川小寨子沟国家级自然保护区绿尾虹雉种群密度调查与栖息地评价

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四川动物 2017年第4期36卷 361-367页

作者：余翔陈俊橙王彬严勇冉江洪贺飞彭波四川大学生命科学学院生物资源与生态环境教育部重点实验室四川省濒危野生动物保护生物学重点实验室成都610064 四川小寨子沟国家级自然保护区管理局四川北川622750

201.年6—8月和201.年3—8月,在四川小寨子沟国家级自然保护区及周边地区,采用绝对密度调查法,对繁殖期绿尾虹雉Lophophorus lhuysii的密度进行了调查,并基于Max Ent对繁殖期绿尾虹雉的栖息地质量进行了评价。结果显示:在保护区及其周... 详细信息

201.年6—8月和201.年3—8月,在四川小寨子沟国家级自然保护区及周边地区,采用绝对密度调查法,对繁殖期绿尾虹雉Lophophorus lhuysii的密度进行了调查,并基于Max Ent对繁殖期绿尾虹雉的栖息地质量进行了评价。结果显示:在保护区及其周边区域内,绿尾虹雉繁殖期常活动于海拔3 500~4 1.0 m靠近阳坡的草甸、灌丛生境。在整个评价区域内适宜栖息地1.0.05 km^2,次适宜栖息地1.1.67 km^2;在保护区内繁殖期绿尾虹雉的平均密度为4.99只/km^2,适宜栖息地49.1. km^2,次适宜栖息地48.27 km^2,推测其种群数量为245只。放牧、资源采集等人类活动是影响绿尾虹雉种群密度的主要因子,因此在本区域的保护区网络间需要加强对人类活动的控制,限制放牧活动,以保护高海拔区域的生物多样性。

关键词：绿尾虹雉种群密度栖息地评价岷山山系小寨子沟保护区

Concise extraction and characterization of the pore-throat network in unconventional hydrocarbon reservoirs: A new perspective

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Petroleum Science 2024年第3期21卷 1474-1487页

作者： Shu-Heng Du yong-Min Shi State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of SciencesBeijing100190China School of Engineering Science University of Chinese Academy of SciencesBeijing100049China School of Earth and Space Sciences Peking UniversityBeijing100871China

In this study,a new image-based method for the extraction and characterization of pore-throat network for unconventional hydrocarbon storage and exploitation is proposed.“Pore-throat solidity”,which is analogous to particle solidity,and a new method for automatic identification of pores and throats in tight sandstone oil reservoirs are ***,the“pore-throat combination”and“pure pore”are defined and distinguished by drawing the cumulative probability curve of the pore-throat solidity and by selecting an appropriate cutoff *** the discrete grid set is recognized as a pore-throat combination,Legendre ellipse fitting and minimum Feret diameter are *** the pore and throat grid sets are identified as pure pores,the pore diameter can be directly *** the new method,the analytical results for the physical parameters and pore radius agree well with most prior *** results comparing the maximum ball and the new model could also prove the accuracy of the latter's in micro and nano *** new model provides a more practical theoretical basis and a new calculation method for the rapid and accurate evaluation of the complex processes of oil migration.

关键词： Hydrocarbon exploitation Pore Throat Porous media Identification

Physics-Informed Neural Networks with Two Weighted Loss Function Methods for Interactions of Two-Dimensional Oceanic Internal Solitary Waves

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Journal of Systems Science & Complexity 2024年第2期37卷 545-566页

作者： SUN Junchao CHEN yong TANG Xiaoyan School of Mathematical Sciences Key Laboratory of Mathematics and Engineering Applications(Ministry of Education)&Shanghai Key Laboratory of PMMPEast China Normal UniversityShanghai 200241China College of Mathematics and Systems Science Shandong University of Science and TechnologyQingdao 266590China

The multiple patterns of internal solitary wave interactions(ISWI)are a complex oceanic *** remote sensing techniques indirectly detect these ISWI,but do not provide information on their detailed structure and ***,the authors considered a three-layer fluid with shear flow and developed a(2+1.Kadomtsev-Petviashvili(KP)model that is capable of describing five types of oceanic ISWI,including O-type,P-type,TO-type,TP-type,and *** learning models,particularly physics-informed neural networks(PINN),are widely used in the field of fluids and internal solitary ***,the authors find that the amplitude of internal solitary waves is much smaller than the wavelength and the ISWI occur at relatively large spatial scales,and these characteristics lead to an imbalance in the loss function of the PINN *** solve this problem,the authors introduce two weighted loss function methods,the fixed weighing and the adaptive weighting methods,to improve the PINN *** successfully simulated the detailed structure and dynamics of ISWI,with simulation results corresponding to the satellite *** particular,the adaptive weighting method can automatically update the weights of different terms in the loss function and outperforms the fixed weighting method in terms of generalization ability.

关键词： Internal solitary wave interactions KP equation PINN method weighted loss function method

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华南陆缘晚中生代造山及其地质意义

中国地质 2013年第1期40卷 86-105页

作者：崔建军张岳桥董树文江博明徐先兵马立成李建华苏金宝李勇中国地质科学院地质力学研究所北京100081 台湾大学地球科学系台北10699 中国地质大学地球科学学院武汉430074

长乐—南澳带位于华南大陆的东南缘,是揭示晚中生代古太平洋板块与欧亚大陆相互作用和华南陆缘地质演化的一条关键性构造带。该构造带的T3-J含煤地层不整合下伏于下白垩统南园组之下,或以角闪岩相包体形式赋存于晚侏罗—早白垩世片麻状... 详细信息

长乐—南澳带位于华南大陆的东南缘,是揭示晚中生代古太平洋板块与欧亚大陆相互作用和华南陆缘地质演化的一条关键性构造带。该构造带的T3-J含煤地层不整合下伏于下白垩统南园组之下,或以角闪岩相包体形式赋存于晚侏罗—早白垩世片麻状花岗岩体内。这些具有透入性混合岩化特征的副变质岩包体(T3-J)与围岩(片麻状花岗岩)发生过同变形,并且被未变形的白垩纪岩体/脉侵入。这些晚三叠—早侏罗世地层的变质和变形具有朝陆内(NW)方向减弱的特征。下白垩统南园组普遍发生褶皱和绿片岩相变质,并且被未变质的上白垩统石帽山群不整合覆盖。长乐—南澳带的主要岩石单元与构造特征表明华南陆缘在晚中生代经历过两期挤压(造山)。在第一期挤压(造山)过程中,T3-J陆相地层发生褶皱和变质。随后,这些经历了变形和变质的T3-J沉积地层与中-上地壳的其他岩石在早白垩世早期发生构造折返,其间伴随着大规模同构造岩浆作用(1.7～1.5 Ma)和区域性混合岩化。在第二期挤压过程中,早白垩世南园组发生褶皱和变质。华南陆缘1.0～1.0 Ma的岩浆杂岩、1.0～90 Ma的A型花岗岩和90～80 Ma的双峰式火成岩可能分别与这次挤压事件及其后的地壳伸展、减薄过程有关。因此,华南晚中生代两大岩浆旋回(1.5～1.0 Ma和1.0～80 Ma)可能受控于同期的两大构造旋回(1.5～1.0 Ma和1.5～80 Ma)。每个构造旋回包括一个地壳受挤压增厚过程和一个随后发生的地壳伸展减薄过程。值得注意的是,华南沿海地区的晚中生代构造-岩浆作用与陆内同期构造-岩浆作用似乎具有可比性。

关键词：长乐-南澳构造带平潭-东山杂岩带福清-云霄变质带晚中生代陆缘造山

A novel weld-pool-length monitoring method based on pixel analysis in plasma arc additive manufacturing

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Advances in Manufacturing 2024年第2期12卷 335-348页

作者： Bao-Ri Zhang yong-Hua Shi Bionic Robot Research Department Ji Hua LaboratoryFoshan528200GuangdongPeople’s Republic of China Guangdong Provincial Engineering Research Center for Special Welding Technology and Equipment School of Mechanical and Automotive EngineeringSouth China University of TechnologyGuangzhou510640People’s Republic of China

The real-time monitoring of the weld pool during deposition is important for automatic control in plasma arc additive *** obtain a high deposition accuracy,it is essential to maintain a stable weld pool *** this study,a novel passive visual method is proposed to measure the weld pool *** the proposed method,the image quality was improved by designing a special visual system that employed an endoscope and a *** also includes pixel brightness-based and gradient-based algorithms that can adaptively detect feature points at the boundary when the weld pool geometry *** algorithm can also be applied to materials with different solidification *** was performed to measure the real weld pool length in world coordinates,and outlier rejection was performed to increase the accuracy of the ***,tests were carried out on the intersection component,and the results showed that the proposed method performed well in tracking the changing weld pool length and was applicable to the real-time monitoring of different types of materials.

关键词： Plasma arc additive manufacturing(PAAM) Weld pool geometry Gradient analysis Real-time detection