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Elevational distribution of forests and its spatiotemporal dynamics in subtropical china from 2000 to 2019

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Science china Earth sciences 2024年第8期67卷 2563-2582页

作者： Zhencan ZHENG liuwen ZHUANG Guofang MIAO Han liu Zhiqiang chenG Wenyu li Rong SHANG peng GONG Jing ming chen institute of Geography Fujian Normal University Key Laboratory of Humid Subtropical Eco-Geographical Process (ministry of Education) Fujian Normal University School of Geographical sciences Fujian Normal University National Land Consolidation Center Ministry of Natural Resources Key Laboratory of Land Consolidation and Rehabilitation Ministry of Natural Resources Key Laboratory of Digital Mapping and Land Information Application Ministry of Natural Resources Department of Geography & Planning University of Toronto Department of Geography The University of Hong Kong

The subtropical region of china possesses abundant forest resources and features a mountainous *** the implementation of policies such as natural forest protection,the Grain for Green Project,and other initiatives since the beginning of the 21st century,coupled with climate change,the forest resources in this region have undergone significant changes compared to historical *** addition,forest resources distributing mainly in mountainous areas also implies that these changes may vary significantly with *** explore the spatiotemporal dynamics of forest distribution in subtropical china since 2000,especially the trend of changes with elevation,we analyzed the data from two land cover products focusing on forest cover and forest *** used a hierarchical approach,in which coarse-classification forest cover data with relatively small uncertainties impose constraints on forest type data with larger uncertainties,to achieve a reasonable balance between obtaining more details and reducing data *** first divided the forest cover data into‘unchanged'and‘changed'*** the constraints by the forest cover results,we further analyzed the‘unchanged'and‘changed'forest *** results indicated that,since the implementation of ecological engineering and management policies,54%of the area in the subtropical region had maintained unchanged forest cover attributes over the past 20 years,which implied the good state of ecological *** results also showed that dynamic conversions existed in the long term between forests and lands for essential production needs like *** elevational variations of forest cover suggested that the dominant changes came from the conversion between forests and croplands in low-elevation regions below 700 m,the conversion between forests and shrublands in mid-elevation regions of 700–1500 m,and the conversion between forests and grasslands in high-elevation regions above 2000 *** the regio

关键词： Subtropical china Land cover Forest cover Forest type Elevational distribution

Single-wall carbon nanotube fiber non-woven fabrics with a high electrothermal heating response

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Nano Research 2024年第6期17卷 5621-5628页

作者： Xinyu Jiao Lele Xu Xinyang Sun Chao shi peng-Xiang Hou Chang liu Hui-ming cheng Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaHefei 230026China Faculty of Materials Science and Engineering/institute of Technology for Carbon Neutrality Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China

Carbon nanotube(CNT)fibers have great promise for constructing multifunctional fabrics with high electrical conductivity,good electro-heating ability,excellent flexibility,and a low ***,the inter-fiber contacts in the fabric greatly reduce these advantages and limit their ***,a simple pressure-fusing method to fabricate single-wall CNT(SWCNT)fiber non-woven fabrics(NWFs)that are composed of interconnected SWCNT fibers with fused joints is reported,which have good flexibility,a low density of 0.46 g/cm^(3),a high electrical conductivity of 3.7×10^(5)S/m,and a record high specific electrical conductivity of 803(S·m^(2))/*** also showed excellent electrical heating ability,so that a temperature of~160℃was rapidly reached at a low voltage of 2 *** with their low density,the SWCNT fiber NWFs are promising for use as a heating unit for low temperature battery protection and de-icing applications.

关键词： carbon nanotube fiber nonwoven fabrics fusing electrothermal heating

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笔谈:透视台湾地区2024年“两项选举”

台湾研究 2024年第1期 1-14页

作者： institute of Taiwan Studies, chinese academy of Social sciences 中国社会科学院台湾研究所

2024年1月13日,台湾地区领导人和立法机构“二合一”选举落下幕。民进党籍候选人赖清德、萧美琴当选台湾地区正副领导人。台湾地区立法机构总额113席中,中国国民党获52席,民进党获51席,民众党获8席,无党籍及未经政党推荐者获2席.

关键词：中国国民党民进党立法机构台湾地区民众党推荐者二合一候选人

The dynamics beamline at SSRF

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Nuclear Science and Techniques 2024年第9期35卷 56-67页

作者： Zhen liu li-Hua Wang Yong Jiang Ya-Jun Tong Hua-chun Zhu Te Ji min chen Zheng Jiang Xiang-Jun Wei Shanghai Advanced Research institute Chinese Academy of SciencesShanghai 201204China ShanghaiTech University Shanghai 201210China

The dynamics beamline(D-line),which combines synchrotron radiation infrared spectroscopy(SR-IR)and energy-disper-sive X-ray absorption spectroscopy(ED-XAS),is the first beamline in the world to realize concurrent ED-XAS and SR-IR measurements at the same sample position on a millisecond time-resolved *** combined technique is effective for investigating rapid structural changes in atoms,electrons,and molecules in complicated disorder systems,such as those used in physics,chemistry,materials science,and extreme ***,ED-XAS and SR-IR can be used independently in the two branches of the *** ED-XAS branch is the first ED-XAS beamline in china,which uses a tapered undulator light source and can achieve approximately 2.5×10^(12)photons/s·300 eV BW@7.2 keV at the sample *** exchange-able polychromator operating in the Bragg-reflection or Laue-transmission configuration is used in different energy ranges to satisfy the requirements for beam size and energy *** focused beam size is approximately 3.5μm(H)×21.5μm(V),and the X-ray energy range is 5–25 *** one-and two-dimensional position-sensitive detectors with frame rates of up to 400 kHz enables time resolutions of tens of microseconds to be *** distinctive techniques,such as the concurrent measurement of in situ ED-XAS and infrared spectroscopy,time-resolved ED-XAS,high-pressure ED-XAS,XMCD,and pump-probe ED-XAS,can be applied to achieve different scientific goals.

关键词： ED-XAS SR-IR Time-resolved D-line SSRF

The Role of Renewable Protocatechol Acid in Epoxy Coating Modification: Significantly Improved Antibacterial and Adhesive Properties

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chinese Journal of Polymer Science 2024年第1期42卷 63-72,I0008页

作者： ming-Xuan chen Jin-Yue Dai li-Yue Zhang Shuai-peng Wang Jing-Kai liu Yong-Gang Wu Xin-Wu Ba Xiao-Qing liu School of Chemistry and Materials Science Hebei UniversityBaoding 071000China Ningbo institute of Materials Technology and Engineering Chinese Academy of SciencesNingbo 315201China Key Laboratory of Marine Materials and Related Technologies Chinese Academy of SciencesNingbo 315201China

It is of great significance to design epoxy coatings with superior antibacterial properties and high adhesive properties, as well as excellent processing, superior durability, and high transparency. However, it is still a challenge because of the common complex design and synthesis. Herein, the bio-based monomer protocatechuic acid(PCA) was used as raw material, the catechol structure with high bonding and antibacterial properties was introduced into the flexible alkane segment of ethylene glycol diglycidyl ether(EGDE) through an efficient, and green method, and it was cured with isophorone diamine(IPDA) to prepare corresponding thermosets. The cured resins exhibited excellent allaround qualities, particularly in bonding and antibacterial. When 30% PCA was added to pure epoxy resin, the adhesion between substrate and coating increased from 4.40 MPa to 13.60 MPa and the antibacterial rate of coating against E. coli and S. aureus could approach 100%. All of this is due to the fact that the catechol structure present in PCA has the ability to interact with various substrates and alter the permeability of bacterial cell membranes. The architecture of this method offers a fresh approach to dealing with the issues of challenging raw material selection and complex synthesis techniques.

关键词： Epoxy coatings Thermosets Catechol structure Antibacterial High adhesion

On-demand engineerable visible spectrum by fine control of electrochemical reactions

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National Science Review 2024年第3期11卷 239-249页

作者： Qirong liu Lei liu Yongping Zheng min li Baofu Ding Xungang Diao Hui-ming cheng Yongbing Tang Advanced Energy Storage Technology Research Center Shenzhen Institute of Advanced TechnologyChinese Academy of Sciences institute of Technology for Carbon Neutrality Shenzhen Institute of Advanced Technology Chinese Academy of Sciences School of Energy and Power Engineering North University of China School of Resource Environment and Safety EngineeringHunan University of Science and Technology School of Energy and Power Engineering Beihang University Shenzhen Key Laboratory of Energy Materials for Carbon Neutrality Shenzhen Institute of Advanced Technology Chinese Academy of Sciences Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences

Tunability of optical performance is one of the key technologies for adaptive optoelectronic applications,such as camouflage clothing, displays, and infrared shielding. High-precision spectral tunability is of great importance for some special applications with on-demand adaptability but remains challenging. Here we demonstrate a galvanostatic control strategy to achieve this goal, relying on the finding of the quantitative correlation between optical properties and electrochemical reactions within materials. An electrochromic electro-optical efficiency index is established to optically fingerprint and precisely identify electrochemical redox reactions in the electrochromic device. Consequently, the charge-transfer process during galvanostatic electrochemical reaction can be quantitatively regulated, permitting precise control over the final optical performance and on-demand adaptability of electrochromic devices as evidenced by an ultralow deviation of lications with strict demand on precise spectral tunability but also will promote in situ quantitative research in a wide range of spectroelectrochemistry, electrochemical energy storage, electrocatalysis, and material chemistry.

关键词： electrochromics fine control spectral tunability high precision galvanostatic control

Multi-prior physics-enhanced neural network enables pixel super-resolution and twin-imagefree phase retrieval from single-shot hologram

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Opto-Electronic Advances 2024年第9期7卷 22-38页

作者： Xuan Tian Runze li Tong peng Yuge Xue Junwei min Xing li chen Bai Baoli Yao State Key Laboratory of Transient Optics and Photonics Xi’an Institute of Optics and Precision MechanicsChinese Academy of SciencesXi’an 710119China University of chinese academy of sciences Beijing 100049China.

Digital in-line holographic microscopy(DIHM)is a widely used interference technique for real-time reconstruction of living cells’morphological information with large space-bandwidth product and compact ***,the need for a larger pixel size of detector to improve imaging photosensitivity,field-of-view,and signal-to-noise ratio often leads to the loss of sub-pixel information and limited pixel ***,the twin-image appearing in the reconstruction severely degrades the quality of the reconstructed *** deep learning(DL)approach has emerged as a powerful tool for phase retrieval in DIHM,effectively addressing these ***,most DL-based strategies are datadriven or end-to-end net approaches,suffering from excessive data dependency and limited generalization ***,a novel multi-prior physics-enhanced neural network with pixel super-resolution(MPPN-PSR)for phase retrieval of DIHM is *** encapsulates the physical model prior,sparsity prior and deep image prior in an untrained deep neural *** effectiveness and feasibility of MPPN-PSR are demonstrated by comparing it with other traditional and learning-based phase retrieval *** the capabilities of pixel super-resolution,twin-image elimination and high-throughput jointly from a single-shot intensity measurement,the proposed DIHM approach is expected to be widely adopted in biomedical workflow and industrial measurement.

关键词： optical microscopy quantitative phase imaging digital holographic microscopy deep learning super-resolution

Changes of the trace metals in ice core during 1915-2016 in coastal eastern Antarctica

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Advances in Climate Change Research 2024年第4期15卷 596-608页

作者： Jing-Wen liu Chuan-Jin li Gui-Tao shi Yan liu Zhi-Heng DU ming-Hu DING Shao-peng GAO Cun-De XIAO shi-Chang KANG Bo SUN State Key Laboratory of the Cryosphere Science Northwest Institute of the Eco-Environment and ResourcesChinese Academy of SciencesLanzhou730000China University of chinese academy of sciences Beijing 100049China Key Laboratory for Polar Science of State Oceanic Administration Polar Research Institute of ChinaShanghai 200136China Key Laboratory of Geographic Information Science(ministry of Education) School of Geographic Sciences and Institute of Eco-ChongmingEast China Normal UniversityShanghai 200241China institute of Tibetan Plateau and Polar Regions Meteorology Chinese Academy of Meteorological SciencesBeijing 100081China Key Laboratory of Tibetan Environment Changes and Land Surface Processes Instituie of the Tibetan PlateauChinese Academy of SciencesBeijing 100101China State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal UniversityBeijing 100875China

Antarctic trace metal records provide important information for grasping the influence of human activities on the environment over the last *** CA2016-75 ice core is located along the East Antarctic Zhongshan Station-Dome A,enhances the record of metals research in the East Antarctic region,and its high-resolution supplies data support for the study of high-frequency climatic drivers and the effect of human activities on the Antarctic environment.A thorough dataset on seven trace metals(Al,Fe,Mn,Cu,Zn,Ba and Pb)in a coastal ice core in eastern Antarctica during the previous 102 years(1915-2016)is presented in this *** has the lowest concentration(9.51±20.95 pg g^(-1)),and Ba has the highest concentration(36.57±51.35 ng g^(-1)).Notable variations are observed between the pre-1968 AD and post-1968 AD phases for Mn,Zn and *** abrupt,remarkable increase in the concentrations coincided with the change of metal smelting production in the southern *** addition to this,it may also be related to local Antarctic scientific research *** and Fe,the primary crustal elements,are essentially obtained from soil dust;Cu shows high crustal enrichment factors(EFc,>10),indicating that it is notably affected by anthropogenic ***,the anthropogenic activities in the Southern Hemisphere have had an impact on lead deposition in *** study not only enriches the trace metal historical record along the Zhongshan Station-Dome A but also provides a high-resolution ice core record,which is very crucial for the reconstruction of trace metal concentration changes in the last 100 years.

关键词： Eastern Antarctica Ice core Trace metals Human activities

Satellite anomaly detection based on reconstruction discrepancy theory utilizing a new dual-branch reconstruction model

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Science china Technological sciences 2024年第10期67卷 3294-3307页

作者： ZHAO HaoTian QIU shi liu ming CAO XiBin Research Center of Satellite Technology School of AstronauticsHarbin Institute of Technology

To enhance the accuracy of deep learning methods based on reconstruction discrepancy in satellite anomaly detection tasks, this study proposes a dual-branch reconstruction model(DBRM) and designs a comprehensive satellite anomaly detection framework around this model. Firstly, we introduce the temporal-channel mixer(TC-Mixer) module, which mainly comprises a self-attention layer for capturing long-range temporal dependencies in telemetry data, and two types of feed-forward networks(FFN) for extracting complex patterns in the temporal and channel dimension of telemetry data. This design endows the TC-Mixer module with robust capabilities for extracting complicated dependencies in telemetry data. Secondly, with the TC-Mixer module as the main component, we designed the DBRM. This model utilizes a shared latent representation layer, allowing the regeneration branch and forecasting branch of the DBRM to share most of the feature extraction network architecture. This approach significantly enhances the model's regression accuracy while reducing computational complexity. Thirdly, using the DBRM as the core network model, we devised a comprehensive satellite anomaly detection framework. This includes an anomaly criterion that considers the reconstruction discrepancy of both the regeneration and forecasting branches, the peak-over-threshold(POT) method for anomaly thresholding, and the MIC-based feature engineering method, etc. Finally, we conducted comparative experiments with several SOTA anomaly detection algorithms on two public and one private satellite anomaly detection datasets. The experimental results validate the effectiveness and superiority of our proposed method.

关键词： anomaly detection reconstruction discrepancy dual-branch reconstruction model (DBRM) satellite telemetry data time series