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High-efficiency and flexible photonic microwave harmonic down-converter based on self-oscillation optical frequency combs

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Chinese Optics Letters 2024年第6期22卷 196-204页

作者： Xin Zhang Tao Pu Huatao Zhu Yunshan Zhang Gengze Wu Jin Li Jilin Zheng college of Information and Communications National University of Defense TechnologyWuhan 430010China college of Communications Engineering Army Engineering University of PLANanjing 210007China college of Electronic and Optical Engineering&college of Flexible Electronics(Future Technology) Nanjing University of Posts and TelecommunicationsNanjing 210023China

Photonic microwave harmonic down-converters (PMHDCs) based on self-oscillation optical frequency combs (OFCs) are interesting because of their broad bandwidth compared with plain optoelectronic oscillators. In this paper, a high-efficiency and flexible PMHDC is proposed and demonstrated. The properties of the OFC, such as the carrier-to-noise ratio (CNR),bandwidth and free spectral range (FSR), and the influence of optical injection, are investigated. The broadband OFC provides a frequency tunable and high-quality local oscillation (LO), which guarantees flexible down-conversion for the radio frequency (RF) signal. The sideband selective amplification (SSA) effect not only improves the conversion efficiency but also promotes single-sideband modulation. The conversion range can reach 100 GHz. The 12–40 GHz RF signal can be downconverted to intermediate frequency (IF) signals with a high conversion efficiency of 14.9 dB. The fixed 40-GHz RF signal is flexibly down-converted to an IF signal with the frequency from 55.4 to 2129.4 MHz. The phase noise of an IF signal at a frequency offset of 10 kHz is the same as that of the input RF signal. The PMHDC shows great performance and will find applications in radio-over-fiber (RoF) networks, electronic warfare receivers, avionics, and wireless communication systems.

关键词： frequency down-conversion optical frequency comb optical injection optoelectronic oscillation

FeNi Prussian blue analogues on highly graphitized carbon nanosheets as efficient glucose sensors

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Rare Metals 2024年第6期43卷 2730-2738页

作者： Jin-Hang Xue Qiu-Hong Sun Cheng Han Yuan-Dong Yang Shao-Jie Xu Qi-Peng Li Jin-Jie Qian college of Life and Environmental Science Wenzhou UniversityWenzhou 325000China college of Chemistry and Materials Engineering Wenzhou UniversityWenzhou 325000China college of Chemistry and Chemical Engineering Zhaotong UniversityZhaotong 657000China

Meeting the continuous glucose monitoring requirements of individuals necessitates the research and development of sensors with high sensitivity and *** this study,a straightforward strategy was proposed for synthesizing ultra-thin oxygen-rich graphitized carbon nanosheets(denoted as GCS-O).These nanosheets are obtained by calcining a topologically two-dimensional indium-based coordination ***,the growth of FeNi Prussian blue analogue(PBA)on GCS-O effectively introduces active sites and increases the nitrogen content within the carbonaceous *** resulting FeNi-PBA/GCS-O composite exhibits excellent glucose sensing performance with a broad linear range of 1 to 1300μmol·L^(-1).Meanwhile,it also achieves a high sensitivity of 2496μA·mmol^(-1)·L·cm^(-2),a limit of detection of 100nmol·L^(-1)(S/N=3),and commendable long-term *** relatively simple synthesis process,exceptional sensitivity,and satisfactory electrochemical sensing performance of FeNi-PBA/GCS-O open up new directions for biosensor applications.

关键词： Coordination polymer Carbon nanosheet Prussian blue analogue Surface reconstruction Glucose oxidation

IQABC-Based Hybrid Deployment Algorithm for Mobile Robotic Agents Providing Network Coverage

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Tsinghua Science and Technology 2024年第2期29卷 589-604页

作者： Shuang Xu Xiaojie Liu Dengao Li Jumin Zhao college of Computer Science and Technology(college of Data Science) Taiyuan University of TechnologyTaiyuan 030024China Pengcheng Laboratory Shenzhen 518055China college of Information and Computer Taiyuan University of TechnologyTaiyuan 030024China

Working as aerial base stations,mobile robotic agents can be formed as a wireless robotic network to provide network services for on-ground mobile devices in a target ***,a challenging issue is how to deploy these mobile robotic agents to provide network services with good quality for more users,while considering the mobility of on-ground *** this paper,to solve this issue,we decouple the coverage problem into the vertical dimension and the horizontal dimension without any loss of optimization and introduce the network coverage model with maximum coverage ***,we propose a hybrid deployment algorithm based on the improved quick artificial bee *** algorithm is composed of a centralized deployment algorithm and a distributed *** proposed deployment algorithm deploy a given number of mobile robotic agents to provide network services for the on-ground devices that are independent and identically *** results have demonstrated that the proposed algorithm deploys agents appropriately to cover more ground area and provide better coverage uniformity.

关键词： wireless robotic networks network coverage deployment algorithm improved quick artificial bee colony

Navigating the hydrogen prospect:A comprehensive review of sustainable source-based production technologies, transport solutions,advanced storage mechanisms, and CCUS integration

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Journal of Energy Chemistry 2024年第10期97卷 166-215页

作者： Sehar Tasleem Chandra Sekhar Bongu Mohan Raj Krishnan Edreese Housni Alsharaeh college of Science and General Studies Alfaisal University

The review is a comprehensive discussion of current research advances,commercial scale developments,challenges,and techno-eco nomics for the entire H2value chain,including production,mainly focusing on sustainable sources,storage,and *** challenges,advantages,and uses of H2energy are included at ***,apart from the sustainable production approaches,the approaches and current developments for combating the carbon dioxide（CO2） emissions from existing H2production facilities are highlighted in terms of ca rbon capture,utilization,and storage（CCUS）.Concisely,the review discusses current material and recent technological adva ncements in developing pilot projects and large-scale establishments for viable and rapidly emerging sou rce-ba sed H2productio ***,the review also aims to provide an in-depthdiscussion and explore current developments based on the advantages of H2energy in terms of its utilization,based on its high energy density,and its ability to be used as a feedstock and *** the other hand,the challenges of H2are also elabo ***,the role of CCUS in a carbon-neutral economy and value chain for minimization of emissions from existing facilities is thoroughly deliberated,and the recent commercial-scale implementation of CCUS technologies is *** the utilization and recycling of captured CO2emissions along with H2to produce e-fuels in terms of current advances is detailed in this *** rthermore,the most applicable,efficient,a nd develo ping approaches are discussed for physical and chemical H2storage,considering recent la rge-scale implementations of liquid carriers and liquid organic hydrogen carriers as storage ***,the review elaborates on recent insights into advances in H2transport infrastructure,including compressed and liquid H2delivery via roads,ships,pipelines,and flight *** review gives precise insights into the recent scenario through an elaborated conclusion of each discussion t

关键词： Carbon capture E-fuels Hydrogen storage Hydrogen utilization Source-based hydrogen Transport infrastructure

Pyridine-regulated Sb@InSbS_(3)ultrafine nanoplates as high-capacity and long-cycle anodes for sodium-ion batteries

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Rare Metals 2024年第5期43卷 2080-2092页

作者： Jia-Ying Ren Xiang-Lin Yu Chang-Miao Chen Xin-Yu Hu Ting Yang Ming Zhang college of Materials Science and Engineering and college of Science Central South University of Forestry and TechnologyChangsha 410004China college of Semiconductors(college of Integrated Circuits) Changsha Semiconductor Technology and Application Innovation Research InstituteHunan UniversityChangsha 410082China

Sb-based materials exhibit considerable potential for sodium-ion storage owing to their high theoretica ***,the bulk properties of Sb-based materials always result in poor cycling and rate *** overcome these issues,pyridine-regulated Sb@InSbS_(3)ultrafine nanoplates loaded on reduced graphene oxides(Sb@InSbS_(3)@rGO)were designed and *** the synthesis process,pyridine was initially adopted to coordinate with In^(3+),and uniformly dispersed In_(2)S_(3)ultrafine nanoplates on reduced graphene oxide were generated after ***,partial In^(3+)was exchanged with Sb^(3+),and Sb@InSbS_(3)@rGO was obtained by using the subsequent annealing *** unique structure of Sb@InSbS_(3)@rGO effectively shortened the transfer path of sodium ions and electrons and provided a high *** the anode in sodium-ion batteries,the Sb@InSbS_(3)@rGO electrode demonstrated a significantly higher reversible capacity better stability(445 m Ah·g^(-1)at 0.1 A·g^(-1)after 200 cycles and 212 mAh·g^(-1)at 2 A·g^(-1)after 1200 cycles),and superior rate(210 mAh·g^(-1)at 6.4 A·g^(-1))than the electrode without pyridine(355 mAh·g-1at 0.1 A·g-1after 55 cycles and 109 mAh·g^(-1)at 2 A·g^(-1)after 770 cycles)Furthermore,full cells were assembled by using the Sb@InSbS_(3)@rGO as anode and Na_(3)V_(2)(PO_(4))_(3)as cathode which demonstrated good cycling and rate performances and exhibited promising application *** results indicate that adjusting the microstructure of electrode materials through coordination balance is A·good strategy for obtaining high-capacity,high-rate,and longcycle sodium storage performances.

关键词： Sodium-ion battery Sb-based anode material Pyridine coordination Reduced size nanostructure Half/full cell

Span-based joint entity and relation extraction augmented with sequence tagging mechanism

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Science China(Information Sciences) 2024年第5期67卷 84-98页

作者： Bin JI Shasha LI Hao XU Jie YU Jun MA Huijun LIU Jing YANG college of Computer National University of Defense Technology

Span-based joint extraction simultaneously conducts named entity recognition(NER) and relation extraction(RE) in a text span form. However, since previous span-based models rely on span-level classifications, they cannot benefit from token-level label information, which has been proven advantageous for the task. In this paper, we propose a sequence tagging augmented span-based network(STSN), a spanbased joint model that can make use of token-level label information. In STSN, we construct a core neural architecture by deep stacking multiple attention layers, each of which consists of three basic attention *** the one hand, the core architecture enables our model to learn token-level label information via the sequence tagging mechanism and then uses the information in the span-based joint extraction; on the other hand, it establishes a bi-directional information interaction between NER and RE. Experimental results on three benchmark datasets show that STSN consistently outperforms the strongest baselines in terms of F1,creating new state-of-the-art results.

关键词： joint extraction named entity recognition relation extraction span sequence tagging mechanism

Fine structure and facet analyses of tunnel-structured FeOOH nanocrystals

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Progress in Natural Science:Materials International 2024年第1期34卷 172-177页

作者： Xuemei Zeng Yanshuai Li Wenjun Song Yun Li Dewu Yin Yifei Yuan Kun He college of Chemistry and Materials Engineering Wenzhou University

The development of energy storage systems in the future relies on identifying suitable target materials and synthesizing target materials with controllable physicochemical properties to unlock their electrochemical contributions. Based on the structure-property-performance relationship established in materials science, it is crucial to determine the fine structure of key functional materials. Among these materials, tunnel-structured β-FeOOH is widely studied due to its low-cost, decent performance and environmental friendliness; yet, its fine structure in terms of the atomic framework and surface configuration has not been well understood. In this work, we successfully synthesized β-FeOOH nanorods and analyzed their crystallographic features via transmission electron microscopy(TEM). By combining ultramicrotome and aberration-corrected scanning TEM with atomic resolution,we first experimentally revealed the structural details of β-FeOOH featuring 1 × 1 tunnels and 2 × 2 tunnels along the c-axis([001]), the same as the nanorod growth direction. The dominant exposed facets of β-FeOOH nanorods were further revealed to be {010}. Such fine structural elucidation unveils the long-existing mystery in this material system, which is expected to contribute to structural/compositional engineering toward functionality optimization in the near future.

关键词： β-FeOOH tunnel Anisotropic growth Atomic resolution Nanorod Energy storage

Demonstration of high-dimensional controlled quantum teleportation for the first time

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Science China(Physics,Mechanics & Astronomy) 2024年第3期67卷 163-164页

作者： Yu-Bo Sheng Lan Zhou college of Electronic and Optical Engineering and college of Flexible Electronics(Future Technology) Nanjing University of Posts and TelecommunicationsNanjing 210023China college of Science Nanjing University of Posts and TelecommunicationsNanjing 210023China

Controlled quantum teleportation(CQT) [1] is the tripartite version of quantum teleportation and it allows the teleportation of an unknown quantum state under the control of a third party. Compared with low-dimensional counterparts,high-dimensional CQT can exhibit larger information transmission capacity and a higher control power [2,3].

关键词： quantum dimensional high

Body size induced changes in metabolic carbon of soil nematodes under N deposition and precipitation regime change in a temperate grassland

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Ecological Processes 2024年第1期13卷 120-131页

作者： Shuyan Cui Xiaomei Mo Guo Zheng college of Life Science Shenyang Normal University

Background Global climate change has resulted in precipitation regimes exhibiting an increasing trend in rainfall intensity but a reduction in its frequency. Nitrogen(N) deposition is a crucial component of the global N cycling. Nematode body size is a trait that responds to climate change and is used as a standard trait-based indicator in soil community analysis. Variations in body size influence metabolic carbon(C). We examined the ways by which body size and metabolic C of nematodes respond to changing precipitation regimes and how N deposition regulates these responses by an 8-year manipulative *** Nematode body size was indicated by the community-weighted mean(CWM) mass. We quantified C metabolism components of soil nematodes including production C, respiration C, and corresponding C use efficiency(CUE) under different precipitation intensities and N addition in a semi-arid steppe on the Mongolian Plateau. The Mantel test was used to determine the correlations between CWM, CUE and environmental factors. The partial least squares path modeling(PLS-PM) was conducted to quantify direct or indirect contributions among latent *** We found that heavy precipitation intensity increased the CWM mass of total nematodes and omnivorespredators without N addition. N addition decreased CWM mass of bacterivores across all the precipitation intensity treatments. Stronger precipitation intensities might be favorable for nematode production and respiration C. Variations in the nematode CWM mass drove the CUE to change with N *** Our findings provide new insights into the mechanisms underlying nematode body size and C metabolism, and highlight that explorative studies, such as manipulative experiments, are needed to identify traits underlying size-related effects and to investigate how they affect CUE of nematodes. These efforts may increase our understanding of how changes in precipitation regimes and N deposition may alter soil nema

关键词： Community-weighted mean Metabolic footprint Nitrogen addition Precipitation intensity