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World Journal of Radiology 2024年第5期16卷 136-138页

作者： Min Ai hang-hang zhang Yi Guo Jun-Bang Feng Department of Anesthesiology Nanan District People’s Hospital of ChongqingChongqing 400060China Department of Breast and Thyroid Surgery Chongqing Bishan District Maternal and Child Health Care HospitalChongqing 402760China Medical Imaging Department Chongqing University Central Hospital(Chongqing Emergency Medical Center)Chongqing 400014China

Determining whether sevoflurane sedation in children leads to“pseudo”prominent leptomeningeal contrast enhancement(pLMCE)on 3 Tesla magnetic resonance imaging will help reduce overdiagnosis by radiologists and clari... 详细信息

关键词： Pediatrics patients Sevoflurane Brain Prominent leptomeningeal contrast enhancement Magnetic resonance imaging

Heterocatalytic ethylene methoxycarbonylation via a pseudo-hydride pathway over Pt_(1)/MoS_(2)

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Science China Chemistry 2024年第8期67卷 2427-2428页

作者： Bo-hang Zhao Bin zhang Institute of Molecular Plus Department of ChemistrySchool of ScienceTianjin UniversityTianjin 300072China

Ethylene (C2H4) methoxycarbonylation (EMC) with CO and methanol (CH3OH) to methyl propanoate (MP) is industrially important due to its 100% atom efficiency [1].However, the heavy reliance on homogeneous Pd-based catalysts and strong acid media over commercial EMC processes still causes economic and environmental concerns [2]. At present, supported single-atom catalysts (SACs) can serve as bridges for accessing homogeneous catalysts in traditional heterogeneous catalytic processes.

关键词： processes. catalytic hydride

Image Segmentation-P300 Selector: A Brain–Computer Interface System for Target Selection

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Computers, Materials & Continua 2024年第5期79卷 2505-2522页

作者： hang Sun Changsheng Li He zhang Mechanical Engineering Nanjing University of Science and TechnologyNanjing210018China

Brain–computer interface (BCI) systems, such as the P300 speller, enable patients to express intentions withoutnecessitating extensive ***, the complexity of operational instructions and the slow pace of characterspelling pose challenges for some patients. In this paper, an image segmentation P300 selector based on YOLOv7-mask and DeepSORT is proposed. The proposed system utilizes a camera to capture real-world objects forclassification and tracking. By applying predefined stimulation rules and object-specificmasks, the proposed systemtriggers stimuli associated with the objects displayed on the screen, inducing the generation of P300 signals in thepatient’s brain. Its video processing mechanism enables the system to identify the target the patient is focusing oneven if the object is partially obscured, overlapped, moving, or changing in number. The system alters the target’scolor display, thereby conveying the patient’s intentions to caregivers. The data analysis revealed that the selfrecognitionaccuracy of the subjects using this method was between 92% and 100%, and the cross-subject P300recognition precision was 81.9%–92.1%. This means that simple instructions such as “Do not worry, just focuson what you desire” effectively discerned the patient’s intentions using the Image Segmentation-P300 selector. Thisapproach provides cost-effective support and allows patients with communication difficulties to easily express theirneeds.

关键词： Brain-computer interface deep learning electroencephalogram P300 YOLOv7-mask

Polymer Mechanochemistry on Reactive Species Generated from Mechanochemical Reactions

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Chinese Journal of Chemistry 2024年第12期42卷 1418-1432页

作者： Xiaolong Chen hang Shen Zhengbiao zhang State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials Suzhou Key Laboratory of Macromolecular Design and Precision SynthesisCollege of ChemistryChemical Engineering and Materials ScienceSoochow UniversitySuzhouJiangsu 215123China

Comprehensive Summary Polymer mechanochemistry on reactive species has attracted more and more attentions over the past 20 years,as the mechanochemical generation of reactive species has a great potential in developing different polymeric materials for various purposes,such as stress detection,self-healing,self-strengthening,controllable degradation and release of small *** this review,we first discuss the recent progress on polymer mechanochemistry of the reactive species that are generated from the mechanochemical reactions of *** types of reactive species,including radical,zwitterion,ionic,carbene and neutral intermediates,and their applications were reviewed in *** mechanochemical reactions are sensitive to the mechanophore structure and polymer framework,we then discuss how mechanophore isomerism,polymer structure,polymer attachment point,and polymer architecture influence the mechanophore *** last,we provide our perspectives on the polymer mechanochemistry of reactivespecies.

关键词： Stimuli-responsive polymers Polymer mechanochemistry Mechanophore Mechanochemical reaction Reactive species

Design of integral sliding mode guidance law based on disturbance observer

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Journal of Systems Engineering and Electronics 2024年第1期35卷 186-194页

作者： ZHOU Jianping zhang Wenjie ZHOU hang LI Qiang XIA Qunli School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China School of Informatic Engineering Mianyang Techers’CollegeMianyang 62100China Beijing Institute of Electronic System Engineering Beijing 100854China Beijing Institute of Space Long March Vehicle Beijing 100076China

With the increasing precision of guidance,the impact of autopilot dynamic characteristics and target maneuvering abilities on precision guidance is becoming more and more *** order to reduce or even eliminate the autopilot dynamic operation and the target maneuvering influence,this paper suggests a guidance system model involving a novel integral sliding mode guidance law(ISMGL).The method utilizes the dynamic characteristics and the impact angle,combined with a sliding mode surface scheme that includes the desired line-ofsight angle,line-of-sight angular rate,and second-order differential of the angular *** the same time,the evaluation scenario considere the target maneuvering in the system as the external disturbance,and the non-homogeneous disturbance observer estimate the target maneuvering as a compensation of the guidance *** proposed system’s stability is proven based on the Lyapunov stability *** simulations reveale that ISMGL effectively intercepted large maneuvering targets and present a smaller miss-distance compared with traditional linear sliding mode guidance laws and trajectory shaping guidance ***,ISMGL has a more accurate impact angle and fast convergence speed.

关键词： disturbance observer pilot dynamics integral sliding mode impact angle constraint maneuvering target

Intraspecific floral colour variation in three Pedicularis species

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Plant Diversity 2024年第2期46卷 274-279页

作者： Qiu-Yu zhang Zhe Chen hang Sun Yang Niu State Key Laboratory of Plant Diversity and Specialty Crops Kunming Institute of BotanyChinese Academy of SciencesKunming 650201YunnanChina University of Chinese Academy of Sciences Beijing 100049China

Flower constancy describes the phenomenon that pollinators tend to successively visit flowers of a single species during foraging,reducing reproductive interference in natural *** extent of flower constancy is largely determined by the floral traits of co-flowering *** higher inter-specific and lower intraspecific differences of floral traits should contribute to a higher level of flower ***,previous studies mainly focused on interspecific difference,and the intraspecific variation(consistency)of floral traits received much less *** hypothesise that selection may favour lower intraspecific floral trait variation in communities composed of multiple co-flowering *** investigated the floral colour variation of three focal Pedicularis species that share pollinators in 19communities composed of either single or multiple Pedicularis *** was quantified using image-based colour analysis as perceived by *** found that most of the intrapopulation floral colour variation was below the colour discrimination threshold of bumblebees,implying strongly constrained by the visual selection by *** to the hypothesis,there is no significant difference in intraspecific floral colour variation between different community *** may be due to the relatively large interspecific floral colour differences of most co-flowering *** influence of community context on intraspecific variation may be reflected in floral traits other than colours.

关键词： Flower constancy Floral colour variation Plantepollinator interactions Pollinator vision

High-frequency magnetic properties of biphase Ce_(2)Fe_(17)N_(3)/α-Fe microflakes with easy-plane anisotropy

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Journal of Rare Earths 2024年第1期42卷 110-115,I0004页

作者： Ke Wang hang zhang Yuandong Huang Zhibiao Xu Fashen Li Tao Wang Key Laboratory for Magnetism and Magnetic Materials of MOE Lanzhou UniversityLanzhou730000China Key Laboratory of Special Function Materials and Structure Design Ministry of EducationLanzhou UniversityLanzhou730000China

Soft magnetic composites(SMCs)are effective as magnetic powder cores in an *** to high saturation magnetization,large magnetocrystalline anisotropy and high operating frequency of M(metal)-RE(rear earth)soft magnetic composites,it is possible to miniaturize inductor cores by reducing total loss,especially eddy current loss and excess loss at high *** this article,the characteristics of Ce_(2)Fe_(17)N_(3)/α-Fe(CFN/F)loss per volume and effective permeability reaching a high frequency of 3 MHz are *** biphase CFN/F composite exhibits a high permeability of 16 at 70 MHz,which is two times greater than that of pure Ce_(2)Fe_(17)N_(3)(CFN)*** total loss is as low as 545 mW/cm^(3)at 3 MHz and 6 *** direct current(DC)-bias properties have a percent of permeability exceeding 65% at H=7960 A/*** phenomenon indicates that our material has a higher working frequency and lower core loss than other materials;the biphase CFN/F structure is a promising and efficient approach for developing the miniaturized radio frequency(RF)inductor core.

关键词： High frequency Soft magnetic composites Easy-plane anisotropy Permeability spectra Core loss Rare earths

Pannexins in the musculoskeletal system:new targets for development and disease progression

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Bone Research 2024年第2期12卷 255-269页

作者： Yan Luo Shengyuan Zheng Wenfeng Xiao hang zhang Yusheng Li Department of Orthopedics Xiangya HospitalCentral South UniversityChangshaHunan 410008China National Clinical Research Center for Geriatric Disorders Xiangya HospitalCentral South UniversityChangshaHunan 410008China Department of Clinical Medicine Xiangya Medicine SchoolCentral South UniversityChangshaHunan 410008China Shenzhen Institute of Advanced Technology Chinese Academy of SciencesShenzhen 518055China

During cell differentiation,growth,and development,cells can respond to extracellular stimuli through communication ***(Panx)family and connexin(Cx)family are two important types of channel-forming *** family contains three members(Panx1-3)and is expressed widely in bone,cartilage and *** there is no sequence homology between Panx family and Cx family,they exhibit similar configurations and *** to Cxs,the key roles of Panxs in the maintenance of physiological functions of the musculoskeletal system and disease progression were gradually revealed ***,we seek to elucidate the structure of Panxs and their roles in regulating processes such as osteogenesis,chondrogenesis,and muscle *** also focus on the comparison between Cx and *** a new key target,Panxs expression imbalance and dysfunction in muscle and the therapeutic potentials of Panxs in joint diseases are also discussed.

关键词： skeletal diseases system

A Multi-Token Sector Antenna Neighbor Discovery Protocol for Directional Ad Hoc Networks

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China Communications 2024年第7期21卷 149-168页

作者： zhang hang Li Bo Yan Zhongjiang Yang Mao Li Xinru School of Electronics and Information Northwestern Polytechnical UniversityXi’an 710072China The 54th Research Institute of CETC Shijiazhuang 050081China

In this paper,we propose a Multi-token Sector Antenna Neighbor Discovery(M-SAND)protocol to enhance the efficiency of neighbor discovery in asynchronous directional ad hoc *** central concept of our work involves maintaining multiple tokens across the *** prevent mutual interference among multi-token holders,we introduce the time and space non-interference ***,we propose a master-slave strategy between *** the master token holder(MTH)performs the neighbor discovery,it decides which 1-hop neighbor is the next MTH and which 2-hop neighbors can be the new slave token holders(STHs).Using this approach,the MTH and multiple STHs can simultaneously discover their neighbors without causing interference with each *** on this foundation,we provide a comprehensive procedure for the M-SAND *** also conduct theoretical analyses on the maximum number of STHs and the lower bound of multi-token generation ***,simulation results demonstrate the time efficiency of the M-SAND *** compared to the QSAND protocol,which uses only one token,the total neighbor discovery time is reduced by 28% when 6beams and 112 nodes are employed.

关键词： multi-token neighbor discovery SAND protocol sector antenna ad hoc network

Understanding adversarial attacks on observations in deep reinforcement learning

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Science China(Information Sciences) 2024年第5期67卷 69-83页

作者： You QIAOBEN Chengyang YING Xinning ZHOU hang SU Jun ZHU Bo zhang Department of Computer Science and Technology Beijing National Research Center for Information Science and Technology Tsinghua-Bosch Joint Center for Machine Learning Institute for Artificial Intelligence Tsinghua University Peng Cheng Laboratory

Deep reinforcement learning models are vulnerable to adversarial attacks that can decrease the cumulative expected reward of a victim by manipulating its observations. Despite the efficiency of previous optimization-based methods for generating adversarial noise in supervised learning, such methods might not achieve the lowest cumulative reward since they do not generally explore the environmental ***, a framework is provided to better understand the existing methods by reformulating the problem of adversarial attacks on reinforcement learning in the function space. The reformulation approach adopted herein generates an optimal adversary in the function space of targeted attacks, repelling them via a generic two-stage framework. In the first stage, a deceptive policy is trained by hacking the environment and discovering a set of trajectories routing to the lowest reward or the worst-case performance. Next, the adversary misleads the victim to imitate the deceptive policy by perturbing the observations. Compared to existing approaches, it is theoretically shown that our adversary is strong under an appropriate noise level. Extensive experiments demonstrate the superiority of the proposed method in terms of efficiency and effectiveness, achieving state-of-the-art performance in both Atari and MuJoCo environments.

关键词： deep learning reinforcement learning adversarial robustness adversarial attack