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Rock magnetic properties and palaeomagnetic results of sediments from a stone implement layer in the Bose Basin, Guangxi

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Science China Earth Sciences 2008年第3期51卷 441-450页

作者： yang xiaoqiang ZHU ZhaoYu ZHANG YiNan LI HuaMei ZHOU WenJuan yang Jie Department of Earth Sciences Sun Yat-Sen UniversityGuangzhou 510275China Guangzhou Institute of Geochemistry Chinese Academy of SciencesGuangzhou 510640China School of Environmental Sciences and Engineering Sun Yat-Sen UniversityGuangzhou 510275China Shenzhen Municipal Bureau of Land Resources and Housing Management Shenzhen 518301China

Directional samples were taken to study rock magnetism and palaeomagnetic records from the Dongsheng profile, which is 5 m thick and on the northwest edge of the Bose Basin. Mineralogy and rock magnetism of typical samples indicate that coarse granular titanomagnetite, and fine-grained hematite, superparamagnetic maghemite formed by pedogenesis are in the sediment, which has undergone many transformative processes during different stages of pedogenesis. Parallel samples were taken for thermal demagnetization (TH) (0 to 680°C) and alternating field (AF) demagnetization (0 to 80 mT) respectively. Experimental results of these two kinds of demagnetization illustrate that there are two or more magnetic components in the samples. Intensity of NRM decreases by almost 60% to 90% rapidly when the temperature ranges from 100°C to 350°C, with a steady magnetic component. It is impossible to analyze the magnetic components at high temperature because those fluctuate widely when the temperature is higher than 400°C. Steady magnetic components from 100°C to 350°C indicate that the remanence was mainly carried by fine-grained hematite formed by pedogenesis, reflecting a change in the geomagnetic field while the magnetite was being oxidized into hematite by chemical weathering after deposition. The formative age of the sediments cannot be obtained by magnetic methods in this profile.

关键词： Bose Basin Dongsheng profile palaeomagnetic records

Mesomechanics Finite-element Method for Determining the Shear Strength of Mudded Intercalation Materials

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Journal of Wuhan University of Technology(Materials Science) 2017年第2期32卷 289-291页

作者：胡启军 SHI Rendan yang xiaoqiang CAI Qijie HE Tianjun HE Leping School of Civil Engineering and Architecture Southwest Petroleum University Chengdu 610500 China School of Transportation and Logistics Southwest Jiaotong University Chengdu 611756 China

A new method regarding mesomechanics finite-element research is proposed to predict the peak shear strength of mudded intercalation materials on a mesoscopic scale. Based on geometric and mechanical parameters, along with the strain failure criteria obtained by sample＇s deformation characteristics, uniaxial compression tests on the sample were simulated through a finite-element model, which yielded values consistent with the data from the laboratory uniaxial compression tests, implying that the method is reasonable. Based on this model, a shear test was performed to calculate the peak shear strength of the mudded intercalation, consistent with values reported in the literature, thereby providing a new approach for investigating the mechanical properties of mudded intercalation materials.

关键词： mudded intercalation mesomechanics finite-element method mesoscale structure shear strength

Low-latitude hydroclimate changes related to paleomagnetic variations during the Holocene in coastal southern China

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Frontiers of Earth Science 2024年第2期18卷 324-335页

作者： Tingwei ZHANG xiaoqiang yang Jian YIN Qiong CHEN Jianfang HU Lu WANG Mengshan JU Qiangqiang WANG School of Earth Science and Engineering/Guangdong Provincial Key Laboratory of Geodynamics and Geohazards/Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Sun Yat-sen UniversityGuangzhou 510275China Institute of Cultural Heritage Shandong UniversityQingdao 266237China State Key Laboratory of Organic Geochemistry Guangzhou Institute of GeochemistryChinese Academy of SciencesGuangzhou 510640China College of Urban and Environmental Sciences Peking UniversityBeijing 100871China Institute of Oceanology Chinese Academy of SciencesQingdao 266071China

The variations in precipitation have displayed a complex pattern in different regions since the *** formation processes may have a significant impact on precipitation,especially during the tropical marine processes and summer monsoon which convey abundant water vapor to coastal southern China and inland ***,we use two 7500 year sedimentary records from the Pearl River Delta and the closed Maar Lake,respectively,in coastal southern China to reconstruct the mid-to-late-Holocene humidity variability and explore its possible relationship with cloud cover modulated by the Earth’s magnetic fields(EMF).Our proxy records document an apparent increase in wetness in coastal southern China between 3.0 and 1.8 kyr *** apparent increase in humidity appears to be consistent with the lower virtual axial dipole moments and,in turn,with a lower *** correlation suggests that the EMF might have been superimposed on the weakened monsoon to regulate the mid-to-late-Holocene hydroclimate in coastal southern China through the medium of galactic cosmic rays,aerosols,and cloud ***,further investigations are needed to verify this interaction.

关键词： hydroclimate variations Earth’s magnetic field coastal southern China the Holocene epoch

Coordination Effect-Promoted Durable Ni(OH)_(2) for Energy-Saving Hydrogen Evolution from Water/ Methanol Co-Electrocatalysis

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Nano-Micro Letters 2022年第12期14卷 176-194页

作者： Guodong Fu Xiaomin Kang Yan Zhang xiaoqiang yang Lei Wang Xian-Zhu Fu Jiujun Zhang Jing-Li Luo Jianwen Liu Shenzhen Key Laboratory of Polymer Science and Technology Guangdong Research Center for Interfacial Engineering of Functional MaterialsCollege of Materials Science and EngineeringShenzhen UniversityShenzhen 518060People’s Republic of China School of Mechanical Engineering University of South ChinaHengyang 421001Hunan ProvincePeople’s Republic of China Institute for Sustainable Energy College of SciencesShanghai UniversityShanghai 200444People’s Republic of China

Electrocatalytic water splitting is a viable technique for generating hydrogen but is precluded from the sluggish kinetics of oxygen evolution reactions(OER).Small molecule oxidation reactions with lower working potentials,such as methanol oxidation reactions,are good alternatives to OER with faster ***,the typically employed Ni-based electrocatalysts have poor activity and ***,a novel three-dimensional(3D)-networking Modoped Ni(OH)_(2) with ultralow Ni-Ni coordination is synthesized,which exhibits a high MOR activity of 100 mA cm^(−2) at 1.39 V,delivering 28 mV dec^(−1) for the Tafel ***,hydrogen evolution with value-added formate co-generation is boosted with a current density of more than 500 mA cm^(−2) at a cell voltage of 2.00 V for 50 h,showing excellent stability in an industrial alkaline concentration(6 M KOH).Mechanistic studies based on density functional the-ory and X-ray absorption spectroscopy showed that the improved performance is mainly attributed to the ultralow Ni-Ni coordination,3D-networking structures and Mo dopants,which improve the catalytic activity,increase the active site density and strengthen the Ni(OH)_(2)3D-networking structures,*** study paves a new way for designing electrocatalysts with enhanced activity and durability for industrial energy-saving hydrogen production.

关键词： Coordination effect Methanol selective oxidation NiMoO4 Formate Energy-saving hydrogen production

Rubik’s cube as in-situ programmable matter and a reconfigurable mechanical metamaterial

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Science China(Technological Sciences) 2024年第10期67卷 3221-3234页

作者： ZHU ShaoWei CHEN Huan yang xiaoqiang TAN Li JIN Shuai CHEN LiMing LIU Tao TAN XiaoJun WANG LianChao WANG Bing MUAMER Kadic State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing UniversityChongqing 400030China College of Aerospace Engineering Chongqing UniversityChongqing 400030China School of Civil Aviation Northwestern Polytechnical UniversityXi’an 710129China National Key Laboratory of Science and Technology on Advanced Composites in Special Environments Harbin Institute of TechnologyHarbin 150080China Institut FEMTO-ST CNRS UMR 6174University BourgogneFranche-ComtBesan¸con 25000France

As part of the 4th industrial revolution,programmable mechanical metamaterials exhibit great application potential in flexible robotics,vibration control,and impact ***,maintaining a programmed state without sustaining the external stimulus is often challenging and leads to additional energy *** by Rubik’s cube,we design and study an in-situ programmable and distribution-reconfigurable mechanical metamaterial(IPDR-MM).A matrix model is developed to model IPDR-MMs and describe their morphological *** on this model,the reinforcement learning method is employed to find the pathways for morphological *** find that IPDR-MMs have controllable stiffness across several orders of magnitude and a wide range of adjustable anisotropies through morphology ***,because of the independence of the directions of morphology transformation and bearing,IPDR-MMs exhibit good stability in bearing and can readily achieve high *** Rubik’s cube-inspired design concept is also instructive for other deformable structures and metamaterials,and the current version of the proposal should be sufficiently illustrative to attract and broaden interdisciplinary interests.

关键词： mechanical metamaterials in-situ programmable distribution-reconfigurable Rubik’s cube controllable stiffness and anisotropy

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论增值税法上的估价规定

政法论丛 2024年第3期 73-90页

作者：杨小强中山大学法学院广东广州510275

增值税立法从交易定性转而重视交易定量,是增值税立法的现代化发展。增值税法上的视同销售、反避税规定、法律的拟制性规定等需要进行估价,参考英国和澳大利亚等国家的立法技术,在我国增值税法上引进资产评估技术是一种极佳的立法选择。

关键词：增值税立法交易价格评估方法

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增值税税率比较:国际立法与中国选择

政法论丛 2022年第3期 76-86页

作者：杨小强中山大学法学院广东广州510275

增值税作为我国第一大税种,其收入再分配效应在很大程度上事关税制公平。国际增值税立法趋势表明,近年来国外增值税标准税率基本稳定,同时各国比较重视民生领域增值税税率的调整,通过低税率、零税率以及免税等方式,克服增值税的累退性... 详细信息

增值税作为我国第一大税种,其收入再分配效应在很大程度上事关税制公平。国际增值税立法趋势表明,近年来国外增值税标准税率基本稳定,同时各国比较重视民生领域增值税税率的调整,通过低税率、零税率以及免税等方式,克服增值税的累退性。为实质性发挥增值税对收入分配的调节作用,平衡增值税税率与国民经济发展的互动关系,有必要进一步简并税率。可能的路径是为普通货物和服务分别设置一档增值税标准税率,并为与民生相关的货物和服务设定相同的优惠税率,以助力我国共同富裕的推进。

关键词：增值税税率收入再分配

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私募基金增值税:国际比较与立法选择

政法论丛 2023年第2期 63-75页

作者：杨小强中山大学法学院广东广州510275

私募基金增值税处理是金融服务增值税立法中的一块高地,涉及增值税与资本利得税、所得税的正确区分。美国、欧盟、新加坡的基金税收立法就此有不同的立法对待。适逢《中华人民共和国增值税法(草案)》已经公布并公开征求意见,如何将私募... 详细信息

私募基金增值税处理是金融服务增值税立法中的一块高地,涉及增值税与资本利得税、所得税的正确区分。美国、欧盟、新加坡的基金税收立法就此有不同的立法对待。适逢《中华人民共和国增值税法(草案)》已经公布并公开征求意见,如何将私募基金增值税处理纳入通盘考量,建议通过国际比较从而作出我国的立法选择。

关键词：私募基金金融服务增值税资本利得税

Southern Hemisphere Westerlies Variations during Last Interglacial: Insights from a Tasmania Speleothem

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Southern Hemisphere Westerlies Variations during Last Interg...