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Exciton Bose–Einstein Condensation in Transition Metal Dichalcogenide Monolayer under In-Plane Magnetic Fields

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Chinese Physics Letters 2024年第8期41卷 69-76页

作者： Dengfeng Wang Yingda Chen Zhi-Chuan Niu Wen-kai Lou kai chang SKLSM Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China College of Materials Science and Opto-electronic Technology Center of Materials Science and Optoelectronics EngineeringUniversity of Chinese Academy of SciencesBeijing 100049China School of Physics Zhejiang UniversityHangzhou 310027China

Based on the Gross–Pitaevskii equation,we theoretically investigate exciton Bose–Einstein condensation(BEC)in transition metal dichalcogenide monolayers(TMDC-MLs)under in-plane magnetic *** observe that the in-plane magnetic fields exert a strong influence on the exciton BEC wave functions in TMDC-MLs because of the mixing of the bright and dark exciton states via Zeeman *** leads to the brightening of the dark exciton BEC *** competition between the dipole–dipole interactions caused by the long-range Coulomb interaction and the Zeeman effect induced by the in-plane magnetic fields can effectively regulate dark exciton BEC *** findings emphasize the utility of TMD-MLs as platforms for investigating collective phenomenon involving excited states.

关键词： effect. Einstein dipole

A Novel Clutter Suppression Algorithm for Low-Slow-Small Targets Detecting Based on Sparse Adaptive Filtering

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Journal of Beijing Institute of Technology 2024年第1期33卷 54-64页

作者： Zeqi Yang Shuai Ma Ning Liu kai chang Xiaode Lyu Aerospace Information Research Institute Chinese Academy of SciencesBeijing 100094China National Key Laboratory of Microwave Imaging Technology Beijing 100190China School of Electronic Electrical and Communication Engineering University of Chinese Academy of SciencesBeijing 100049China Northern Institute of Electronic Equipment Beijing 100083China

Passive detection of low-slow-small(LSS)targets is easily interfered by direct signal and multipath clutter,and the traditional clutter suppression method has the contradiction between step size and convergence *** this paper,a frequency domain clutter suppression algorithm based on sparse adaptive filtering is *** pulse compression operation between the error signal and the input reference signal is added to the cost function as a sparsity constraint,and the criterion for filter weight updating is improved to obtain a purer echo *** the same time,the step size and penalty factor are brought into the adaptive iteration process,and the input data is used to drive the adaptive changes of parameters such as step *** proposed algorithm has a small amount of calculation,which improves the robustness to parameters such as step size,reduces the weight error of the filter and has a good clutter suppression performance.

关键词： passive radar interference suppression sparse representation adaptive filtering

Recent developments in selective laser processes for wearable devices

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Bio-Design and Manufacturing 2024年第4期7卷 517-547页

作者： Youngchan Kim Eunseung Hwang chang kai kaichen Xu Heng Pan Sukjoon Hong Optical Nanoprocessing Lab Department of Mechanical EngineeringBK21 FOUR ERICA-ACE CenterHanyang University55 Hanyangdaehak-RoSangnok-GuAnsan 15588Republic of Korea Multiscale Manufacturing Lab J.Mike Walker’66 Department of Mechanical EngineeringTexas A&M UniversityCollege StationTX 77843USA State Key Laboratory of Fluid Power and Mechatronic Systems School of Mechanical EngineeringZhejiang UniversityHangzhou 310058China

Recently,the increasing interest in wearable technology for personal healthcare and smart virtual/augmented reality applications has led to the development of facile fabrication *** have long been used to develop original solutions to such challenging technological problems due to their remote,sterile,rapid,and site-selective processing of *** this review,recent developments in relevant laser processes are summarized under two separate ***,transformative approaches,such as for laser-induced graphene,are *** addition to design optimization and the alteration of a native substrate,the latest advances under a transformative approach now enable more complex material compositions and multilayer device configurations through the simultaneous transformation of heterogeneous precursors,or the sequential addition of functional layers coupled with other electronic *** addition,the more conventional laser techniques,such as ablation,sintering,and synthesis,can still be used to enhance the functionality of an entire system through the expansion of applicable materials and the adoption of new ***,various wearable device components developed through the corresponding laser processes are discussed,with an emphasis on chemical/physical sensors and energy *** addition,special attention is given to applications that use multiple laser sources or processes,which lay the foundation for the all-laser fabrication of wearable devices.

关键词： Selective laser process Wearable device Transformative approach Laser-induced graphene Ablation Sintering Synthesis

DOA estimation of high-dimensional signals based on Krylov subspace and weighted l_(1)-norm

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Journal of Systems Engineering and Electronics 2024年第3期35卷 532-540,F0002页

作者： YANG Zeqi LIU Yiheng ZHANG Hua MA Shuai chang kai LIU Ning LYU Xiaode Aerospace Information Research Institute Chinese Academy of SciencesBeijing 100094China National Key Laboratory of Microwave Imaging Technology Beijing 100190China School of Electronic Electrical and Communication Engineering University of Chinese Academy of SciencesBeijing 100049China Northern Institute of Electronic Equipment Beijing 100191China

With the extensive application of large-scale array antennas,the increasing number of array elements leads to the increasing dimension of received signals,making it difficult to meet the real-time requirement of direction of arrival(DOA)estimation due to the computational complexity of *** subspace algorithms require estimation of the covariance matrix,which has high computational complexity and is prone to producing spurious *** order to reduce the computational complexity of DOA estimation algorithms and improve their estimation accuracy under large array elements,this paper proposes a DOA estimation method based on Krylov subspace and weighted l_(1)-*** method uses the multistage Wiener filter(MSWF)iteration to solve the basis of the Krylov subspace as an estimate of the signal subspace,further uses the measurement matrix to reduce the dimensionality of the signal subspace observation,constructs a weighted matrix,and combines the sparse reconstruction to establish a convex optimization function based on the residual sum of squares and weighted l_(1)-norm to solve the target *** results show that the proposed method has high resolution under large array conditions,effectively suppresses spurious peaks,reduces computational complexity,and has good robustness for low signal to noise ratio(SNR)environment.

关键词： direction of arrival(DOA) compressed sensing(CS) Krylov subspace l_(1)-norm dimensionality reduction

Solid solution strategy modulated defects engineering of (Cr1-xVx)2AlC MAX phase toward superior electromagnetic wave absorption

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Rare Metals 2024年第7期43卷 3205-3219页

作者： Ji-Lin Gou Yu-kai chang Shu Liu Peng-Hui Li Ping-Hao Cui Qian-Ku Hu Li-Bo Wang Xin Zhang Jun-kai Wang Qi-Xun Xia Ai-Guo Zhou School of Materials Science and Engineering Henan Polytechnic University Key Laboratory for Microstructural Material Physics of Hebei Province School of ScienceYanshan University State Key Laboratory of Metastable Materials Science and Technology Yanshan University

Defects engineering is an effective strategy for manipulating electromagnetic parameters and enhancing electromagnetic wave（EMW） absorption ***,the relationship between them is not clear,especially in solid solution *** this work,a series of(Cr1-xVx)2AlC MAX phase solid solutions with layered structure were prepared via tuning the ratio of Cr and V to explore their EMW absorption *** experimental results indicated that the doping of V atoms at the M-site could effectively regulate its impedance matching and EMW absorption properties by introducing appropriate numbers of defects in the crystal,such as twin boundaries,dislocations and lattice *** them,if Cr:V=3:1,Cr1.5V0.5AlC,as radar absorption materials,could reach a strong reflection loss of-51.8 dB at the frequency of 12.8 GHz under an ultra-thin thickness of 1.3 *** reflection loss value could attain-10 dB in a wide frequency range of 2.7-18 GHz and thickness range of 1-5 *** addition,after high temperature and acid-alkali immersion treatment,this sample still had good EMW absorption capability,and the effective absorption bandwidth was enhanced from 2.3 to 2.6 GHz after concentrated acid immersion or 3.1 GHz after concentrated alkali *** work has great reference significance for the research and development of high-performance MAX-based EMW absorption materials in harsh environments.

关键词： MAX phases Solid solution Defects engineering Electromagnetic wave absorption Harsh environments

Semi-quantitative analysis of the structural evolution of mesophase pitch-based carbon foams by Raman and FTIR spectroscopy

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新型炭材料（中英文） 2024年第4期39卷 668-680页

作者： LIU Yue chang Sheng-kai SU Zhan-peng HUANG Zu-jian QIN Ji YANG Jian-xiao Hunan Province Key Laboratory for Advanced Carbon Materials and Applied Technology College of Materials Science and EngineeringHunan UniversityChangsha410082China

Graphitized carbon foams(GFms)were prepared using mesophase pitch(MP)as a raw material by foaming(450℃),pre-oxidation(320℃),carbonization(1000℃)and graphitization(2800℃).The differences in structure and properties of GFms prepared from different MP precursors pretreated by ball milling or liquid phase extraction were investigated and compared,and semi-quantitative calculations were conducted on the Raman and FTIR spectra of samples at each preparation ***-quantitat-ive spectroscopic analysis provided detailed information on the structure and chemical composition changes of the MP and GFm de-rived from *** with microscopic observations,the change from precursor to GFm was *** results showed that ball milling concentrated the distribution of aromatic molecules in the pitch,which contributed to uniform foaming to give a GFm with a uniform pore distribution and good *** phase extraction helped remove light components while retaining large aromatics to form graphitic planes with the largest average size during post-treatment to produce a GFm with the highest degree of graphitization and the fewest open pores,giving the best compression resistance(2.47 MPa),the highest thermal conductivity(64.47 W/(m·K))and the lowest electrical resistance(13.02μΩ·m).Characterization combining semi-quantitative spectroscopic ana-lysis with microscopic observations allowed us to control the preparation of the MP-derived GFms.

关键词： Mesophase pitch Carbon foams Raman FTIR Graphitization

“考古视野下东北亚地区古代文明的交流与互鉴”国际学术研讨会纪要

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北方文物 2024年第2期 107-112页

作者：刘宇枫常凯吉林大学考古学院吉林大学边疆考古研究中心

2023年10月14—15日,由吉林大学边疆考古研究中心主办、吉林省文物考古研究所协办的“考古视野下东北亚地区古代文明的交流与互鉴”国际学术研讨会在吉林省长春市召开。开幕式由吉林大学边疆考古研究中心主任王立新主持,吉林大学边疆考... 详细信息

2023年10月14—15日,由吉林大学边疆考古研究中心主办、吉林省文物考古研究所协办的“考古视野下东北亚地区古代文明的交流与互鉴”国际学术研讨会在吉林省长春市召开。开幕式由吉林大学边疆考古研究中心主任王立新主持,吉林大学边疆考古研究中心学术委员会主任朱泓、中央民族大学边疆考古研究院院长魏坚、吉林省文物考古研究所党支部书记吴辉分别致辞。

关键词：边疆考古研究古代文明党支部书记吉林大学王立新中央民族大学东北亚地区国际学术研讨会

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日钢高炉高铝矿冶炼的优化措施

炼铁 2024年第1期43卷 33-38页

作者：罗力张强常凯日照钢铁控股集团有限公司炼铁制造部山东日照276800

日钢高炉高铝矿冶炼过程中,面临烧结矿的软熔性能变化大,炉渣熔化温度及黏度上升等问题。为此,采取一系列优化措施:①不同矿种优化搭配,烧结矿加块矿,槽下高、低碱度烧结矿块矿混匀,改善炉料软熔性能;②在厚焦层基础上探索合适矿层厚度... 详细信息

日钢高炉高铝矿冶炼过程中,面临烧结矿的软熔性能变化大,炉渣熔化温度及黏度上升等问题。为此,采取一系列优化措施:①不同矿种优化搭配,烧结矿加块矿,槽下高、低碱度烧结矿块矿混匀,改善炉料软熔性能;②在厚焦层基础上探索合适矿层厚度,适当减薄矿层,炉腰矿层厚度维持在0.35m左右,以利于改善矿石熔化性,增强炉况抗波动能力;③提镁降钙,优化渣相,二元碱度控制在1.25,(MgO)<15%,镁铝比维持在0.75左右,保证炉渣的流动性和稳定性。采用以上措施后,日钢高炉炉况顺行,抗波动能力增强,燃料消耗长期维持在较低水平。

关键词：高炉高铝矿软熔性能矿层厚度镁铝比

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子宫内膜异位症患者生育力评估方法

中国实用妇科与产科杂志 2024年第5期40卷 503-506页

作者：易晓芳郑韵熹常凯凯复旦大学附属妇产科医院上海200011

子宫内膜异位症从病理性、医源性以及特发性因素等多方面降低女性生育力,采用适宜方法(结合患者年龄、病情、抗米勒管激素及窦卵泡计数等)评估女性卵巢储备功能、预测受孕与妊娠维持能力以及分娩风险,可以帮助有生育意愿的患者充分了解... 详细信息

子宫内膜异位症从病理性、医源性以及特发性因素等多方面降低女性生育力,采用适宜方法(结合患者年龄、病情、抗米勒管激素及窦卵泡计数等)评估女性卵巢储备功能、预测受孕与妊娠维持能力以及分娩风险,可以帮助有生育意愿的患者充分了解生育力现状,从而有利于选择最佳诊疗策略,尽可能实现生育意愿。

关键词：子宫内膜异位症生育力评估卵巢储备功能