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Isotropic Thermal Expansivity and Anisotropic Compressibility of ReB2

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Chinese Physics Letters 2011年第3期28卷 172-175页

作者： LIU Xi LIU wei he Qiang DENG Li-wei WANG he-Jin he duan-wei LI Bao-Sheng School of Earth and Space Sciences Peking UniversityBeijing 100871 Mineral Physics Institute State University of New YorkStony BrookNew York 11794USA Institute of Atomic and Molecular Physics Sichuan UniversityChengdu 610065

We experimentally investigated some of the mechanical properties of ReB2 under high temperature/pressure(TIP)***-T experiments(up to 600℃at 1 atm)were carried out in a high-T oven attached to a conventional x-ray diffractometer whereas high-P experiments(up to about 42 GPa at 25℃)were conducted in a diamond-anvil cell using synchrotron x-ray ***-T data suggest a highly isotropic thermal expansivity whereas high-P data suggest a highly anisotropic compressibility for ReB2.

关键词： conditions ReB2 diffractometer

Electrical Characterization in the Phase Transition between Cubic PbCrO_(3) Perovskites at High Pressures

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Chinese Physics Letters 2013年第11期30卷 160-163页

作者： WANG Wen-Dan he duan-wei XIAO Wan-Sheng WANG Shan-Min XU Ji-An Institute of Atomic and Molecular Physics Sichuan UniversityChengdu 610065 Guangzhou Institute of Geochemistry Chinese Academy of SciencesGuangzhou 510640 Institute of Fluid Physics and National Key Laboratory of Shockwave and Detonation Physics China Academy of Engineering PhysicsMianyang 621900

By in situ x-ray diffraction,an isostructural phase transition between two kinds of the cubic PbCrO_(3) perovskites at around 1.6 GPa and room temperature with a 9.8%volume change is ***,we have synthesized this cubic PbCrO_(3)perovskite *** we report our high-pressure in situ electrical resistance measurements up to 4.1 GPa for this perovskite *** room temperature,the resistance shows special changes at 1.2 and 2.7 *** may indicate the starting and ending points of this *** 4.1 GPa,the negative temperature resistance coefficient is observed,which means that phase Ⅱ could be considered as a semiconductor according to our present measurement.

关键词： resistance perovskite cubic

Prediction of solar activities:Sunspot numbers and solar magnetic synoptic maps

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Science China Earth Sciences 2024年第8期67卷 2460-2477页

作者： Rui ZHUO Jiansen he Die duan Rong LIN Ziqi WU Limei YAN Yong wei School of Earth and Space Sciences Peking UniversityBeijing 100091China College of Advanced Interdisciplinary Studies National University of Defense TechnologyChangsha 410073China Centre for Mathematical Plasma Astrophysics Department of MathematicsKU LeuvenLeuven 3001Belgium Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China

The evolution of solar magnetic fields is significant for understanding and predicting solar *** our knowledge of solar magnetic fields largely depends on the photospheric magnetic *** this paper,based on the spherical harmonic expansion of the photospheric magnetic field observed by Wilcox Solar Observatory,we analyze the time series of spherical harmonic coefficients and predict Sunspot Number as well as synoptic maps for Solar Cycle *** find that solar maximum years have complex short-period disturbances,and the time series of coefficient g_(7)~0 is nearly in-phase with Sunspot Number,which may be related to solar meridional *** Long Short-Term Memory networks(LSTM),our prediction suggests that the maximum of Solar Cycle 25 is likely to occur in June 2024 with an error of 8 months,the peak sunspot number may be 166.9±22.6,and the next solar minimum may occur around January *** incorporating Empirical Mode Decomposition,we enhance our forecast of synoptic maps truncated to Order 5,validating their relative *** prediction not only addresses a gap in forecasting the global distribution of the solar magnetic field but also holds potential reference value for forthcoming solar observation plans.

关键词： Solar activity prediction Solar magnetic field Spherical harmonic expansion Long-Short Term Memory(LSTM) Empirical Mode Decomposition(EMD)

Porous nanocomposites with enhanced intrinsic piezoresistive sensitivity for bioinspired multimodal tactile sensors

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Microsystems & Nanoengineering 2024年第1期10卷 243-256页

作者： Jianpeng Zhang Song wei Caichao Liu Chao Shang Zhaoqiang he Yu duan Zhengchun Peng State Key Laboratory of Radio Frequency heterogeneous Integration(Shenzhen University) School of Physics and Optoelectronic EngineeringShenzhen University518060 ShenzhenGuangdong ProvinceP.R.China Linksense Technology Ltd. 518060 ShenzhenGuangdong ProvinceP.R.China

In this work,we propose porous fluororubber/thermoplastic urethane nanocomposites(PFTNs)and explore their intrinsic piezoresistive sensitivity to *** experiments reveal that the intrinsic sensitivity of the PFTN-based sensor to pressure up to 10 kPa increases up to 900%compared to the porous thermoplastic urethane nanocomposite(PTN)counterpart and up to 275%compared to the porous fluororubber nanocomposite(PFN)*** pressures exceeding 10 kPa,the resistance-pressure relationship of PFTN follows a logarithmic function,and the sensitivity is 221%and 125%higher than that of PTN and PFN,*** the excellent intrinsic sensitivity of the thick PFTN film,a single sensing unit with integrated electrode design can imitate human skin for touch detection,pressure perception and traction *** sensing range of our multimodal tactile sensor reaches~150 Pa,and it exhibits a linear fit over 97%for both normal pressure and shear *** also demonstrate that an electronic skin,made of an array of sensing units,is capable of accurately recognizing complex tactile interactions including pinch,spread,and tweak motions.

关键词： sensation intrinsic modal

Insight into the development of electrolytes for aqueous zinc metal batteries from alkaline to neutral

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Chinese Chemical Letters 2024年第2期35卷 232-241页

作者： An duan Sha Luo wei Sun School of Materials and Energy University of Electronic Science and Technology of ChinaChengdu 611731China

Aqueous zinc metal batteries are considered as promising candidates for next-generation electrochemical energy storage devices,especially for large-scale energy storage,due to the advantages of high-safety,high energy density and low *** the bridge connecting cathode and anode,electrolyte provides a realistic operating *** alkaline and neutral aqueous zinc metal batteries,issues associated with electrolyte and anode are still *** this review,we reveal the development and evolution of electrolytes for aqueous zinc metal batteries from alkaline to neutral via the description of fundamentals and challenges in terms of comparison and *** also elaborate the strategies in electrolytes regulation and highlight the basic roles and progresses in additives engineering.

关键词： Aqueous electrolytes Zinc metal batteries pH-dependent chemistry Electrolyte regulation Additives engineering

Joint Sample Position Based Noise Filtering and Mean Shift Clustering for Imbalanced Classification Learning

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Tsinghua Science and Technology 2024年第1期29卷 216-231页

作者： Lilong duan wei Xue Jun Huang Xiao Zheng School of Computer Science and Technology Anhui University of TechnologyMaanshan 243032China Institute of Artificial Intelligence Hefei Comprehensive National Science CenterHefei 230088China

The problem of imbalanced data classification learning has received much *** classification algorithms are susceptible to data skew to favor majority samples and ignore minority *** weighted minority oversampling technique(MWMOTE)is an effective approach to solve this problem,however,it may suffer from the shortcomings of inadequate noise filtering and synthesizing the same samples as the original minority *** this end,we propose an improved MWMOTE method named joint sample position based noise filtering and mean shift clustering(SPMSC)to solve these ***,in order to effectively eliminate the effect of noisy samples,SPMsC uses a new noise filtering mechanism to determine whether a minority sample is noisy or not based on its position and distribution relative to the majority *** that MWMOTE may generate duplicate samples,we then employ the mean shift algorithm to cluster minority samples to reduce synthetic replicate ***,data cleaning is performed on the processed data to further eliminate class *** on extensive benchmark datasets demonstrate the effectiveness of SPMsC compared with other sampling methods.

关键词： imbalanced data classification oversampling noise filtering clustering

UAV swarm air combat maneuver decision-making method based on multi-agent reinforcement learning and transferring

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Science China(Information Sciences) 2024年第8期67卷 49-66页

作者： Zhiqiang ZheNG Chen wei Haibin duan State Key Laboratory of Virtual Reality Technology and Systems School of Automation Science and Electrical Engineering Beihang University

During short-range air combat involving unmanned aircraft vehicle(UAV) swarms, UAVs must make accurate maneuver decisions based on information from both enemy and friendly UAVs. This dual requirement of competition and cooperation presents a significant challenge in the field of unmanned air combat. In this paper, a method based on multi-agent reinforcement learning(MARL) is proposed to address this issue. An actor network containing three subnetworks that can handle different types of situational information is designed. hence, the results from simpler one-on-one scenarios are leveraged to enhance the complex swarm air combat training process. Separate state spaces for local and global information are designed for the actor and critic networks. A detailed reward function is proposed to encourage *** prevent lazy participants in air combat, a reward assignment operation is applied to distribute these dense rewards. Simulation testing and ablation experiments demonstrate that both the transfer operation and reward assignment operation can effectively deal with the swarm air combat scenario, and reflect the effectiveness of the proposed method.

关键词： UAV swarm short-range air combat multi-agent reinforcement learning reward assignment transfer

金刚石压砧内单轴应力场对物质状态方程测量的影响

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物理学报 2008年第6期57卷 3397-3401页

作者：王江华贺端威四川大学原子与分子物理研究所成都610065

金刚石压砧的几何结构使得在高压下封垫内的样品通常处于单轴应力场中:压砧轴向加载应力最大,径向应力最小.由于金刚石压砧内非静水压单轴应力场的影响,用传统的高压原位X射线衍射方法测得的物质压缩曲线一般位于理想静水压压缩曲线之上... 详细信息

金刚石压砧的几何结构使得在高压下封垫内的样品通常处于单轴应力场中:压砧轴向加载应力最大,径向应力最小.由于金刚石压砧内非静水压单轴应力场的影响,用传统的高压原位X射线衍射方法测得的物质压缩曲线一般位于理想静水压压缩曲线之上.利用金刚石压砧径向X射线衍射技术以及晶格应变理论,结合最近的钨、金刚石和硼六氧样品的高压原位同步辐射径向X射线衍射实验结果,从宏观差应力、样品强度、标压物质和待测物质强度的关系三个方面分析讨论了金刚石压砧内单轴应力场对物质状态方程测量的影响及解决方案.

关键词：金刚石压砧单轴应力场高压原位X射线衍射状态方程

Control of temperature dependent viscosity for manufacturing of Bi-doped active fiber

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International Journal of Extreme Manufacturing 2024年第3期6卷 522-530页

作者： Rui duan Jingfei Chen Hao Ke Tianxia wei Ke Zhang Xueliang Li Xu Feng Qiuju Zheng Zhixue he Jianrong Qiu Shifeng Zhou State Key Laboratory of Luminescent Materials and Devices School of Materials Science and EngineeringSouth China University of TechnologyGuangzhou 510640People’s Republic of China Guangdong Provincial Key Laboratory of Fiber Laser Materials and Applied Techniques Guangdong Engineering Technology Research and Development Center of Special Optical Fiber Materials and DevicesGuangzhou 510640People’s Republic of China School of Materials Science and Engineering Qilu University of TechnologyJinanPeople’s Republic of China Peng Cheng Laboratory Shenzhen 518000People’s Republic of China College of Optical Science and Engineering State Key Laboratory of Modern Optical InstrumentationZhejiang UniversityHangzhou 310027People’s Republic of China

Bi-activated photonic materials are promising for various applications in high-capacity telecommunication,tunable laser,and advanced bioimaging and *** various Bi-doped material candidates have been explored,manufacturing of Bi heavily doped fiber with excellent optical activity remains a long-standing ***,a novel viscosity evolutional behavior mediated strategy for manufacturing of Bi-doped active fiber with high dopant solubility is *** intrinsic relation among the evolution of Bi,reaction temperature and viscosity of the glass system is ***,the effective avenue to prevent the undesired deactivation of Bi during fiber drawing by tuning the temperature dependent viscosity evolution is *** applying the strategy,for the first time we demonstrate the success in fabrication of heavily doped Bi active ***,the principal fiber amplifier device is constructed and broadband optical signal amplification is *** findings indicate the effectiveness of the proposed temperature dependent viscosity mediated strategy for developing novel photonic active fiber,and they also demonstrate the great potential for application in the next-generation high-capacity telecommunication system.

关键词： infrared luminescence active fiber optical amplification