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Petrogenesis and tectonic implications of the Silurian adakitic granitoids in the eastern segment of the Qilian Orogenic Belt,Northwest China

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Acta Geochimica 2024年第1期43卷 72-86页

作者： Jiao-Long Zhao Xiao-Jun Huang Pei-Qing Hu Zhen-Xi Yang Ying Fan er-Teng Wang Fu-Bo Yang Jing-Yu Zhang School of Earth Sciences Key Laboratory of Mineral Resources in Western China(Gansu Province)Lanzhou UniversityLanzhou 730000China Nuclear Industry 247 Brigade Tianjin North China Geological Survey BureauTianjin 301800China Fourth Institute of Geological and Mineral Exploration of Gansu Provincial Bureau of Geology and Mineral Resources Jiuquan 735000China

Geodynamic mechanism responsible for the generation of Silurian granitoids and the tectonic evolution of the Qilian orogenic belt remains controversial. In this study, we report the results of zircon u–Pb age, and systematic whole-rock geochemical data for the Haoquangou and Liujiaxia granitoids within the North Qilian orogenic belt and the Qilian Block, respectively, to constrain their petrogenesis, and the Silurian tectonic evolution of the Qilian orogenic belt. Zircon u–Pb ages indicate that the Haoquangou and Liujiaxia intrusions were emplaced at423 ± 3 Ma and 432 ± 4 Ma, respectively. The Haoquangou granodiorites are calc-alkaline, while the Liujiaxia granites belong to the high-K calc-alkaline *** are peraluminous in composition and have relatively depleted Nd isotopic [ε_(Nd)(t) =(-3.9 – + 0.6)] characteristics compared with regional basement rocks, implying their derivation from a juvenile lower crust. They show adakitic geochemical characteristics and were generated by partial melting of thickened lower continental crust. Postcollisional extensional regime related to lithospheric delamination was the most likely geodynamic mechanism for the generation of the Haoquangou granodiorite, while the Liujiaxia granites were generated in a compressive setting during continental collision between the Qaidam and Qilian blocks.

关键词： Silurian adakitic granitoids Petrogenesis Tectonic setting Qilian Orogenic Belt

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NiS ultrafine nanorod with translational and rotational symmetry

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National Science Review 2024年第7期11卷 218-225页

作者： Jianxin Kang Qi Hu Ruixuan Zhang Ang Gao Zhongning Huang Ziming Su Ke Pei Qinghua Zhang Li-Min Liu Renchao Che Lin Gu er-Jia Guo Lin Guo School of Chemistry Beihang University Laboratory of Advanced Materials Shanghai Key Lab of Molecular Catalysis and Innovative Materials Academy for Engineering&Technology Fudan University Zhejiang Laboratory Beijing National Center for Electron Microscopy and Laboratory of Advanced Materials School of Materials Science and Engineering Tsinghua University Beijing National Laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of Sciences School of Physics Beihang University

Anisotropy is a significant and prevalent characteristic of materials, conferring orientation-dependent properties, meaning that the creation of original symmetry enables key functionality that is not found in nature. Even with the advancements in atomic machining, synthesis of separated symmetry in different directions within a single structure remains an extraordinary challenge. Here, we successfully fabricate NiS ultrafine nanorods with separated symmetry along two directions. The atomic structure of the nanorod exhibits rotational symmetry in the radial direction, while its axial direction is characterized by divergent translational symmetry, surpassing the conventional crystalline structures known to date. It does not fit the traditional description of the space group and the point group in three dimensions, so we define it as a new structure in which translational symmetry and rotational symmetry are separated. Further corroborating the atomic symmetric separation in the electronic structure, we observed the combination of stripe and vortex magnetic domains in a single nanorod with different directions, in accordance with the atomic *** manipulation of nanostructure at the atomic level introduces a novel approach to regulate new properties finely, leading to the proposal of new nanotechnology mechanisms.

关键词： separated symmetry NiS anisotropy structure atomic machining magnetic domain

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基于属性散射中心卷积核调制的SAR目标识别深层网络

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雷达学报（中英文） 2024年第2期13卷 443-456页

作者：李毅杜兰周可儿杜宇昂西安电子科技大学雷达信号处理全国重点实验室西安710071

卷积神经网络(CNN)的特征提取能力与其参数量有关,一般来说,参数量越多,CNN的特征提取能力越强。但要学好这些参数需要大量的训练数据,而在实际应用中,可用于模型训练的合成孔径雷达(SAR)图像往往是有限的。减少CNN的参数量可以降低对... 详细信息

卷积神经网络(CNN)的特征提取能力与其参数量有关,一般来说,参数量越多,CNN的特征提取能力越强。但要学好这些参数需要大量的训练数据,而在实际应用中,可用于模型训练的合成孔径雷达(SAR)图像往往是有限的。减少CNN的参数量可以降低对训练样本的需求,但同时也会降低CNN的特征表达能力,影响其目标识别性能。针对此问题,该文提出一种基于属性散射中心(ASC)卷积核调制的SAR目标识别深层网络。由于SAR图像具有电磁散射特性,为了提取更符合SAR目标特性的散射结构和边缘特征,所提网络使用预先设定的具有不同指向和长度的ASC核对少量CNN卷积核进行调制以生成更多卷积核,从而在降低网络参数量的同时保证其特征提取能力。此外,该网络在浅层使用ASC调制卷积核来提取更符合SAR图像特性的散射结构和边缘特征,而在高层使用CNN卷积核来提取SAR图像的语义特征。由于同时使用ASC调制卷积核和CNN卷积核,该网络能够兼顾SAR目标的电磁散射特性和CNN的特征提取优势。使用实测SAR图像进行的实验证明了所提网络可以在降低对训练样本需求的同时保证优秀的SAR目标识别性能。

关键词：合成孔径雷达(SAR) 目标识别卷积神经网络(CNN) 属性散射中心(ASC) 卷积核调制

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黄金时代的阴影:20世纪美国人文学科博士危机及启示

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清华大学教育研究 2024年第2期45卷 71-83,143页

作者：陈尔东罗英姿南京农业大学公共管理学院江苏南京210095

基于历史演进视角剖析,美国人文博士生教育在20世纪经历由高速扩张,到引发危机,再到培养策略调整的发展历程。繁荣的美国高等教育黄金年代在促进人文学科博士生教育快速发展的同时,也为持续数十年的人文学科博士危机埋下隐患;美国人文... 详细信息

基于历史演进视角剖析,美国人文博士生教育在20世纪经历由高速扩张,到引发危机,再到培养策略调整的发展历程。繁荣的美国高等教育黄金年代在促进人文学科博士生教育快速发展的同时,也为持续数十年的人文学科博士危机埋下隐患;美国人文学科博士危机其本质是博士学位获得者与大学终身教职之间的自然衔接关系消失,根深蒂固的学术接班人培养理念与培养方式难以适应博士生个人发展诉求。进一步分析发现,人文博士危机的出现及加重同美国博士生教育基本特征相关,包括市场导向、非中心化、结构化等。为促进人文学科博士生教育持续发展,美国学界聚焦于“培养公共人文学者”议题,强调在培养学科继承人、促进多元化职业发展以及提升人文学科社会价值三者间实现平衡。由此借鉴,在我国高等教育高速发展,博士生教育空前繁荣的历史背景下,既需要培养能够走出校园、服务公共文化事业的人文学者,也需要警惕教育市场化所衍生的功利倾向与短视问题,并借助毕业博士追踪数据持续为教育领域提供反馈。

关键词：人文学科博士博士生培养美国博士生教育

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Metal-to-insulator transition in oxide semimetals by anion doping

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Interdisciplinary Materials 2024年第3期3卷 358-368页

作者： Haitao Hong Huimin Zhang Shan Lin Jeffrey A.Dhas Binod Paudel Shuai Xu Shengru Chen Ting Cui Yiyan Fan Dongke Rong Qiao Jin Zihua Zhu Yingge Du Scott A.Chambers Chen Ge Can Wang Qinghua Zhang Le Wang Kui-juan Jin Shuai Dong er-Jia Guo Beijing National Laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of SciencesBeijingChina Department of Physics&Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijingChina Key Laboratory of Quantum Materials and Devices of Ministry of Education School of PhysicsSoutheast UniversityNanjingChina Materials Science and Technology Division Oak Ridge National LaboratoryOak RidgeTennesseeUSA Physical and Computational Sciences Directorate Pacific Northwest National LaboratoryRichlandWashingtonUSA School of Chemical Biological and Environmental EngineeringOregon State UniversityCorvallisOregonUSA Beijing Advanced Innovation Center for Materials Genome Engineering Department of Physical ChemistryUniversity of Science and Technology BeijingBeijingChina Environmental Molecular Sciences Laboratory Pacific Northwest National LaboratoryRichlandWashingtonUSA Songshan Lake Materials Laboratory DongguanGuangdongChina

Oxide semimetals exhibiting both nontrivial topological characteristics stand as exemplary parent compounds and multiple degrees of freedom,offering a promise for the realization of novel electronic *** this work,we report the structural and transport phase transition in an oxide semimetal,SrNbO_(3),achieved through effective anion ***,the resistivity increased by more than three orders of magnitude at room temperature upon *** extent of electronic modulation in SrNbO_(3)is strongly correlated with misfit strain,underscoring its phase instability to both chemical doping and crystallographic symmetry *** first-principles calculations,we discern that elevating the level of nitrogen doping induces an upward shift in the conductive bands of SrNbO_(3−δ)N_(δ).Consequently,a transition from a metallic state to an insulating state becomes apparent as the nitrogen concentration reaches a threshold of 1/*** investigation shows effective anion engineering in oxide semimetals,offering pathways for manipulating their physical properties.

关键词： anion doping metal-to-insulator transition oxide semimetal phase transition

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基于EFDC模型的表面流人工湿地水力性能和净化效果影响因素分析

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农业工程学报 2024年第7期40卷 172-181页

作者：王佳儿崔远来张博超廖斌贺天忠郭健武汉大学水资源与水电工程科学国家重点实验室武汉430072 湖北省漳河工程管理局荆门448156

为探究长宽比、水深和水力负荷对表面流人工湿地水力性能和净化效果的影响及其定量关系,采用EFDC(environmental fluid dynamics Code)模型建立表面流人工湿地水动力-水质耦合模型并对模型进行率定和验证,基于构建的模型设置3因素6水平... 详细信息

为探究长宽比、水深和水力负荷对表面流人工湿地水力性能和净化效果的影响及其定量关系,采用EFDC(environmental fluid dynamics Code)模型建立表面流人工湿地水动力-水质耦合模型并对模型进行率定和验证,基于构建的模型设置3因素6水平的全因子模拟试验,通过分析216组试验结果研究湿地长宽比、水深和水力负荷及其交互作用对湿地水力性能和净化效果的影响,进而采用多元非线性回归模型将多因子影响与7个评价指标之间建立定量关系。结果表明:长宽比、水深和水力负荷之间的交互作用对水力性能和净化效果均有显著影响(P<0.05)。构建的参数与评价指标的回归模型说明水力效率、有效容积率和莫里尔离散指数与长宽比呈指数相关,总氮浓度去除率与水深呈指数相关,回归方程的建模决定系数均大于0.9,经试验数据验证的相对误差在20%以下,说明模型是可靠的。研究可为表面流人工湿地设计和运行提供依据。

关键词：磷氮湿地水力性能净化效果 EFDC模型

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Skeletal contraction:A novel strategy to access multisubstituted cyclobutane

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Green Synthesis and Catalysis 2022年第1期3卷 1-3页

作者： Chunfa Xu V.u.Bhaskara Rao Fen-er Chen Institute of Pharmaceutical Science and Technology College of ChemistryFuzhou UniversityFuzhou 350108China Department of Chemical Biology Max Planck Institute for Molecular PhysiologyDortmund 44227Germany Engineering Center of Catalysis and Synthesis for Chiral Molecules Department of ChemistryFudan UniversityShanghai 200433China Shanghai Engineering Center of Industrial Asymmetric Catalysis for Chiral Drugs Fudan UniversityShanghai 200433China

The polysubstituted and spirocyclic cyclobutanes were efficiently constructed by the utilization of a novel skeletal contraction strategy which only took one-step synthesis from the readily accessible *** mechanistic studies indicated that a key intermediate N-aminated pyrrolidine was formed initially and subsequent extrusion of a nitrogen via a radical pathway completed the *** practical methodology was further highlighted by the concise,formal synthesis of the cytotoxic natural product piperarborenine B.

关键词： Cyclobutane Skeletal contraction Hypervalent iodine Pyrrolidines Piperarboreine B

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Strong Anisotropic Order Parameters at All-Nitride Ferromagnet/Superconductor Interfaces

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Chinese Physics Letters 2024年第2期41卷 102-111页

作者： Qiao Jin Meng Yang Guozhu Song Nan Zhao Shengru Chen Haitao Hong Ting Cui Dongke Rong Qianying Wang Yiyan Fan Chen Ge Can Wang Jiachang Bi Yanwei Cao Liusuo Wu Shanmin Wang Kui-Juan Jin Zhi-Gang Cheng er-Jia Guo Beijing National Laboratory for Condensed Matter Physics and Institute of PhysicsChinese Academy of SciencesBeijing 100190China Department of Physics&Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Department of Physics Southern University of Science and TechnologyShenzhen 518055China Songshan Lake Materials Laboratory Dongguan 523808China Ningbo Institute of Materials Technology&Engineering Chinese Academy of SciencesNingbo 315201China

Proximity effects between superconductors and ferromagnets(SC/FM)hold paramount importance in comprehending the spin competition transpiring at their *** competition arises from the interplay between Cooper pairs and ferromagnetic exchange *** proximity effects between transition metal nitrides(TMNs)are scarcely investigated due to the formidable challenges of fabricating high-quality SC/FM *** fabricated heterostructures comprising SC titanium nitride(TiN)and FM iron nitride(Fe_(3)N)with precise chemical compositions and atomically well-defined *** magnetoresistance of Fe_(3)N/TiN heterostructures shows a distinct magnetic anisotropy and strongly depends on the external ***,the superconducting transition temperatureT_(C) and critical field of TiN experience notable suppression when proximity to Fe_(3)*** observe the intriguing competition of interfacial spin orientations near𝑇T_(C)(∼1.25 K).These findings not only add a new materials system for investigating the interplay between superconductor and ferromagnets,but also potentially provide a building block for future research endeavors and applications in the realms of superconducting spintronic devices.

关键词： proximity Superconductor titanium

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基于模态筛选的滚动轴承微小故障诊断研究

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机械设计与制造 2024年第9期403卷 169-174页

作者：郭跃楠杜福嘉黄康王二朋中国科学院国家天文台南京天文光学技术研究所江苏南京210042 中国科学院天文光学技术重点实验室(南京天文光学技术研究所) 江苏南京210042 中国科学院大学北京100049

滚动轴承的自转、部件相互作用和强干扰使测量的振动信号复杂,而滚动轴承的早期损伤类故障特征信息弱小,导致故障特征难以有效提取从而影响故障诊断,因此提出一种敏感模态筛选方法来提高故障诊断的正确性。采用变分模态分解算法对信号... 详细信息

滚动轴承的自转、部件相互作用和强干扰使测量的振动信号复杂,而滚动轴承的早期损伤类故障特征信息弱小,导致故障特征难以有效提取从而影响故障诊断,因此提出一种敏感模态筛选方法来提高故障诊断的正确性。采用变分模态分解算法对信号进行自适应分解,提取信号的局部特征。基于排列熵的不变性和对冲击信号的敏感性,提出故障因子的敏感模态筛选方法对信号进行重构,抑制振动信号中的干扰和噪声。通过仿真和实验对所提方法进行了验证,结果表明,相比其他处理方法,所提方法信噪比提高了60.5%,误差降低了52.6%,同时故障诊断正确率提高了24.3%,说明了该方法的有效性。

关键词：滚动轴承 VMD 模态筛选排列熵故障因子故障诊断

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Characteristics of American Scholars’Research on Chinese Medical Classics and Their Contributions

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Chinese Journal of Integrative Medicine 2020年第8期26卷 629-632页

作者： WANG er-liang CHEN Xiao School of Basic Medicine Shanghai University of Traditional Chinese MedicineShanghai 201203China

Chinese medical classics are important carriers for the inheritance,innovation and development of academic thoughts of Chinese medicine(CM),containing rich thoughts on diagnosis and treatment as well as therapeutic principles of *** international exchange of CM has a very long *** the development of society,Western scholars in modern times are deepening their researches on Chinese medical *** would provide a new way for promoting CM in Western countries to investigate researches made by famed American scholars and their academic viewpoints.

关键词： Chinese medicine classics international exchange American scholar

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