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UAV-Assisted Dynamic Avatar Task Migration for Vehicular Metaverse Services: A Multi-Agent Deep Reinforcement Learning Approach

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IEEE/CAA Journal of Automatica Sinica 2024年第2期11卷 430-445页

作者： Jiawen Kang Junlong Chen Minrui Xu Zehui xiong Yutao Jiao Luchao han Dusit Niyato Yongju Tong Shengli Xie IEEE School of Automation Guangdong University of TechnologyGuangzhou 510006China 111 Center for Intelligent Batch Manufacturing based on IoT Technology Guangzhou 510006China Key Laboratory of Intelligent Information Processing and System Integration of IoT Ministry of EducationGuangzhou 510006China School of Computer Science and Engineering Nanyang Technological UniversitySingaporeSingapore Pillar of Information Systems Technology and Design Singapore University of Technology and DesignSingaporeSingapore College of Communication Engineering Army Engineering University of PLANanjing 210007China National Natural Science Foundation of China Beijing 100085China Key Laboratory of Intelligent Detection and IoT in Manufacturing Ministry of EducationGuangzhou 510006China Guangdong Key Laboratory of IoT Information Technology Guangzhou 510006China

Avatars, as promising digital representations and service assistants of users in Metaverses, can enable drivers and passengers to immerse themselves in 3D virtual services and spaces of UAV-assisted vehicular Metaverses. However, avatar tasks include a multitude of human-to-avatar and avatar-to-avatar interactive applications, e.g., augmented reality navigation,which consumes intensive computing resources. It is inefficient and impractical for vehicles to process avatar tasks locally. Fortunately, migrating avatar tasks to the nearest roadside units(RSU)or unmanned aerial vehicles(UAV) for execution is a promising solution to decrease computation overhead and reduce task processing latency, while the high mobility of vehicles brings challenges for vehicles to independently perform avatar migration decisions depending on current and future vehicle status. To address these challenges, in this paper, we propose a novel avatar task migration system based on multi-agent deep reinforcement learning(MADRL) to execute immersive vehicular avatar tasks dynamically. Specifically, we first formulate the problem of avatar task migration from vehicles to RSUs/UAVs as a partially observable Markov decision process that can be solved by MADRL algorithms. We then design the multi-agent proximal policy optimization(MAPPO) approach as the MADRL algorithm for the avatar task migration problem. To overcome slow convergence resulting from the curse of dimensionality and non-stationary issues caused by shared parameters in MAPPO, we further propose a transformer-based MAPPO approach via sequential decision-making models for the efficient representation of relationships among agents. Finally, to motivate terrestrial or non-terrestrial edge servers(e.g., RSUs or UAVs) to share computation resources and ensure traceability of the sharing records, we apply smart contracts and blockchain technologies to achieve secure sharing management. Numerical results demonstrate that the proposed approach

关键词： Avatar blockchain metaverses multi-agent deep reinforcement learning transformer UAVs

Ca and Sr co-doping induced oxygen vacancies in 3DOM La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)catalysts for boosting low-temperature oxidative coupling of methane

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Journal of Energy Chemistry 2024年第4期91卷 331-344页

作者： Tongtong Wu Yuechang Wei Jing xiong Yitao Yang Zhenpeng Wang Dawei han Zhen Zhao Jian Liu State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing 102249China Key Laboratory of Optical Detection Technology for Oil and Gas China University of PetroleumBeijing 102249China

It is urgent to develop catalysts with application potential for oxidative coupling of methane(OCM)at relatively lower ***,three-dimensional ordered macro porous(3 DOM)La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)(A_(2)B_(2)O_(7)-type)catalysts with disordered defective cubic fluorite phased structure were successfully prepared by a colloidal crystal template method.3DOM structure promotes the accessibility of the gaseous reactants(O2and CH4)to the active *** co-doping of Ca and Sr ions in La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)catalysts improved the formation of oxygen vacancies,thereby leading to increased density of surface-active oxygen species(O_(2)^(-))for the activation of CH4and the formation of C2products(C2H6and C2H4).3DOM La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)catalysts exhibit high catalytic activity for OCM at low temperature.3DOM La1.7Sr0.3Ce1.7Ca0.3O7-δcatalyst with the highest density of O_(2)^(-)species exhibited the highest catalytic activity for low-temperature OCM,i.e.,its CH4conversion,selectivity and yield of C2products at 650℃are 32.2%,66.1%and 21.3%,*** mechanism was proposed that the increase in surface oxygen vacancies induced by the co-doping of Ca and Sr ions boosts the key step of C-H bond breaking and C-C bond coupling in catalyzing low-temperature *** is meaningful for the development of the low-temperature and high-efficient catalysts for OCM reaction in practical application.

关键词： 3DOM catalysts Ca ions Sr ions Low-temperature oxidative couplingof methane Oxygen vacancies O_(2)^(-) species

Effect of Fe_(2)O_(3)on the Structure,Physical Properties and Crystallization of CaO-Al_(2)O_(3)-SiO_(2)Glass

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Journal of Wuhan University of Technology(Materials Science) 2024年第4期39卷 954-961页

作者：张峰 xiong Dehua 谢俊张继红 han Jianjun CHEN Dequan WEN Zhongquan FAN Zhenhua CHEN Lina SUN Tengfei State Key Laboratory of Silicate Materials for Architectures Wuhan University of TechnologyWuhan 430070China Hepu Research Center for Silicate Materials Industry Technology Beihai 536100China Hainan Institute of Wuhan University of Technology Sanya 430079China Shenzhen Research Institute of Wuhan University of Technology Shenzhen 518000China Chongqing Polycomp Inter-national Corporation Chongqing 400400China

The calcium aluminosilicate-based glasses(CaO-Al_(2)O_(3)-SiO_(2),CAS)with different Fe_(2)O_(3)content(0.10wt%,0.50wt%,0.90wt%,and 1.30wt%)were prepared by traditional melt-quenching *** glass network structure,thermal and mechanical properties,and crystallization behavior changes were investigated by nuclear magnetic resonance spectrometer,Fourier-transform infrared spectro-photometer,X-ray diffractometer,differential scanning calorimetry and field emission scanning electron microscope *** change of Q^(n)in glass structures reveals the glass network connectivity decreases due to the increasing content of Fe_(2)O_(3)addition,resulting in the increasing of non-bridging number in glass *** glass densities slightly rise from 2.644 to 2.681 g/cm^(3),while Vickers’s hardness increases at first,from 6.469 to 6.901 GPa,then slightly drops to 6.745 GPa,with Fe_(2)O_(3)content *** is almost no thermal expansion coefficient change from different Fe_(2)O_(3)*** glass transmittance in visible range gradually decreases with higher Fe_(2)O_(3)content,resulting from the strong absorption of Fe^(2+)and Fe^(3+)*** calculated activation energy from thermal analysis results first decreases from 282.70 to 231.18 kJ/mol,and then increases to 244.02 kJ/mol,with the Fe_(2)O_(3)content increasing from 0.10wt%to 1.30wt%.Meanwhile,the maximum Avrami constant of 2.33 means the CAS glasses exhibit two-dimensional *** of the CAS glass-ceramics samples contain main crystal phase of anorthite,the microstructure appears lamellar and columnar crystals.

关键词： calcium aluminosilicate glass network structure physical properties crystallization

Visualizing the crystallization of sodium chloride under supersaturated condition

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Nano Research 2024年第8期17卷 7786-7792页

作者： Mao Ye Tao Xu Yuwei xiong Yatong Zhu Mingrui Zhou Longxiang han Jinyi Sun Ming Qin Litao Sun SEU-FEI Nano-Pico Center Key Laboratory of MEMS of Ministry of EducationSchool of Integrated CircuitsSoutheast UniversityNanjing 210096China

Crystallization in supersaturated solution plays a fundamental role in a variety of natural and industrial ***,a thorough understanding of crystallization phenomena in supersaturated solution is still difficult because the real-time visualization of crystallization processes under supersaturated condition is a great ***,an electron beam-induced crystallization method was carried out in in situ liquid cell transmission electron microscopy(TEM)to visualize the crystallization of NaCl under supersaturated condition in real *** steps and behaviors in the crystallization of NaCl were captured and clarified,including the growth of NaCl nanocrystals with different morphologies,the formation of initial crystalline seeds from amorphous ion clusters,and the non-equilibrium growth behaviors caused by uneven distribution of precursor *** study provides the real-time visualization of detailed nucleation and growth behaviors in NaCl crystallization and brings an ideal strategy for investigating crystallization phenomena under supersaturated condition.

关键词： crystallization in situ liquid cell transmission electron microscopy(TEM) electron-water interaction sodium chloride

Artificial intelligence in the anterior segment of eye diseases

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International Journal of Ophthalmology(English edition) 2024年第9期17卷 1743-1751页

作者： Yao-Hong Liu Lin-Yu Li Si-Jia Liu Li-xiong Gao Yong Tang Zhao-Hui Li zi Ye School of Medicine Nankai UniversityTianjin 300071China Medical School of Chinese PLA Beijing 100039China Department of Ophthalmology Chinese PLA General HospitalBeijing 100039China Chinese PLA General Hospital Medicine Innovation Research Department Beijing 100039China

Ophthalmology is a subject that highly depends on imaging *** intelligence(AI)technology has great potential in medical imaging analysis,including image diagnosis,classification,grading,guiding treatment and evaluating *** combination of the two can realize mass screening of grass-roots eye health,making it possible to seek medical treatment in the mode of“first treatment at the grass-roots level,two-way referral,emergency and slow treatment,and linkage between the upper and lower levels”.On the basis of summarizing the AI technology carried out by scholars and their teams all over the world in the field of ophthalmology,quite a lot of studies have confirmed that machine learning can assist in diagnosis,grading,providing optimal treatment plans and evaluating prognosis in corneal and conjunctival diseases,ametropia,lens diseases,glaucoma,iris diseases,*** paper systematically shows the application and progress of AI technology in common anterior segment ocular diseases,the current limitations,and prospects for the future.

关键词： artificial intelligence anterior segment ocular disease ametropia glaucoma

Tuning microstructures of Mg-Ce-Ni hydrogen storage alloys via Cu and carbon nanotube additions

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Nano Research 2024年第8期17卷 7203-7211页

作者： Linlin Zhang Liang xiong Bingyang Gao Qingyun Shi Ying Wang Zhiya han Zhenhua Zhang Chunli Wang Limin Wang Yong Cheng State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China Purification Equipment Research Institute of CSIC Handan 056002China

Mg-based alloys are regarded as highly promising materials for hydrogen *** significant improvements of the properties for Mg-based alloys,challenges such as slow hydrogen absorption/desorption kinetics and high thermodynamic stability continue to limit their practical *** this study,to assess hydrogen storage alloys with enhanced properties,incorporating both internal microstructure modulation through the preparation of amorphous/nanocrystalline structures and surface property enhancement with the addition of Cu and carbon nanotubes(CNTs),the kinetic properties of activation and hydrogenation,thermodynamic properties,and dehydrogenation kinetics are *** results reveal a complementary interaction between the added Cu and CNTs,contributing to the superior hydrogen storage performance observed in sample 7A-2Cu-1CNTs with an amorphous/nanocrystalline structure compared to the other experimental ***,the samples are fully activated after the initial hydrogen absorption and desorption cycle,demonstrating outstanding hydrogenation kinetics under both high and low temperature experimental *** noteworthy is that the hydrogen absorption exceeds 1.8 wt.% within one hour at 333 ***,the activation energy for dehydrogenation is decreased to 64.71 kJ·mol^(–1).This research may offer novel insights for the design of new-type Mg-based hydrogen storage alloys,which possess milder conditions for hydrogen absorption and desorption.

关键词： Mg-Ni-Ce alloy hydrogen storage amorphous/nanocrystalline structure kinetics Cu and carbon nanotubes(CNTs)codoping

DENND1A desensitizes granulosa cells to FSH by arresting intracellular FSHR transportation

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Science China(Life Sciences) 2024年第8期67卷 1620-1634页

作者： Yunde Dou Rusong Zhao han Wu Zhiheng Yu Changjian Yin Jie Yang Chaoyan Yang Xiaohua Luan Yixiao Cheng Tao Huang Yuehong Bian Shan han Yuqing Zhang Xin Xu zi-Jiang Chen han Zhao Shigang Zhao Institute of Women Children and Reproductive HealthShandong UniversityJinan 250012China State Key Laboratory of Reproductive Medicine and Offspring Health Jinan 250012China Key laboratory of Reproductive Endocrinology of Ministry of Education Shandong UniversityJinan 250012China Shandong Key Laboratory of Reproductive Medicine Shandong UniversityJinan 250012China Shandong Provincial Clinical Research Center for Reproductive Health Jinan 250012China National Research Center for Assisted Reproductive Technology and Reproductive Genetics Shandong UniversityJinan 250012China The Affiliated Suzhou Hospital of Nanjing Medical University Suzhou Municipal HospitalNanjing Medical UniversitySuzhou 215008China Gusu School Nanjing Medical UniversitySuzhou 215000China Guangdong Provincial People’s Hospital Guangdong Academy of Medical SciencesGuangzhou 510080China Guangdong-Hong Kong Metabolism&Reproduction Joint Laboratory Guangdong Second Provincial General HospitalGuangzhou 510317China Reproductive Medicine Center Guangdong Second Provincial General HospitalGuangzhou 510317China Research Unit of Gametogenesis and Health of ART-Offspring Chinese Academy of Medical Sciences(No.2021RU001)Jinan 250012China Shanghai Key Laboratory for Assisted Reproduction and Reproductive Genetics Shanghai 200127China Center for Reproductive Medicine Renji HospitalSchool of MedicineShanghai Jiao Tong UniversityShanghai 200127China

Polycystic ovary syndrome(PCOS)is a complex ***-wide association studies(GWAS)have identified several genes associated with this condition,including ***1A encodes a clathrin-binding protein that functions as a guanine nucleotide exchange factor involved in vesicular ***,the specific role of DENND1A in reproductive hormone abnormalities and follicle development disorders in PCOS remain poorly *** this study,we investigated DENND1A expression in ovarian granulosa cells(GCs)from PCOS patients and its correlation with *** results revealed an upregulation of DENND1A expression in GCs from PCOS cases,which was positively correlated with testosterone *** further explore the functional implications of DENND1A,we generated a transgenic mouse model overexpressing Dennd1a(TG mice).These TG mice exhibited subfertility,irregular estrous cycles,and increased testosterone production following PMSG ***,the TG mice displayed diminished responsiveness to FSH,characterized by smaller ovary size,less well-developed follicles,and abnormal expressions of FSH-priming ***,we found that Dennd1a overexpression disrupted the intracellular trafficking of follicle stimulating hormone receptor(FSHR),promoting its internalization and inhibiting *** findings shed light on the reproductive role of DENND1A and uncover the underlying mechanisms,thereby contributing valuable insights into the pathogenesis of PCOS and providing potential avenues for drug design in PCOS treatment.

关键词： PCOS DENND1A FSHR ovarian granulosa cells

Identification and validation of a new prognostic signature based on cancer-associated fibroblast-driven genes in breast cancer

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World Journal of Clinical Cases 2024年第4期12卷 700-720页

作者： zi-Zheng Wu Yuan-Jun Wei Tong Li Jie Zheng Yin-Feng Liu Meng han Diagnosis and Treatment Center The First Hospital of QinhuangdaoQinhuangdao 066000Hebei ProvinceChina Department of General Surgery Hebei Medical UniversityShijiazhuang 050000Hebei ProvinceChina Breast Disease Diagnosis and Treatment Center The First Hospital of QinhuangdaoHebei Medical UniversityQinhuangdao 066000Hebei ProvinceChina Breast Disease Diagnosis and Treatment Center Chengde Medical CollegeChengde 067000Hebei ProvinceChina

BACKGROUND Breast cancer(BC),a leading malignant disease,affects women all over the *** associated fibroblasts(CAFs)stimulate epithelial-mesenchymal transition,and induce chemoresistance and *** To establish a CAFs-associated prognostic signature to improve BC patient out-come *** We retrieved the transcript profile and clinical data of 1072 BC samples from The Cancer Genome Atlas(TCGA)databases,and 3661 BC samples from the The Gene Expression *** and immune cell infiltrations were quantified using CIBERSORT ***-associated gene identification was done by weighted gene co-expression network analysis.A CAF risk signature was established via univariate,least absolute shrinkage and selection operator regression,and mul-tivariate Cox regression *** receiver operating characteristic(ROC)and Kaplan-Meier curves were employed to evaluate the predictability of the ***,a nomogram was developed with the risk score and patient clinical *** Spearman's correlations analysis,the relationship between CAF risk score and gene set enrichment scores were *** samples were collected to validate gene expression by quantitative real-time polymerase chain reaction(qRT-PCR).RESULTS Employing an 8-gene(IL18,MYD88,GLIPR1,TNN,BHLHE41,DNAJB5,FKBP14,and XG)signature,we attemp-ted to estimate BC patient *** on our analysis,high-risk patients exhibited worse outcomes than low-risk *** analysis revealed the risk score as an independent indicator of BC patient *** analysis exhibited satisfactory nomogram *** area under the curve showed 0.805 at 3 years,and 0.801 at 5 years in the TCGA *** also demonstrated that a reduced CAF risk score was strongly associated with enhanced chemotherapeutic *** risk score was significantly correlated with most hallmark gene ***,the prognostic signature were further validated by qRT-

关键词： Breast cancer Prognosis Gene signature The Cancer Genome Atlas The Gene Expression Omnibus

Cognitive dysfunction in schizophrenia patients caused by downregulation of γ-aminobutyric acid receptor subunits

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World Journal of Psychiatry 2024年第6期14卷 784-793页

作者： Xi Chen Ya-Nan Zhou Xiao-zi Lu Ren-Jiao Li Yi-Fan xiong Xia Sheng Wei-Wei Zhu Department of Child and Adolescent Psychiatric Brain Hospital of Hunan ProvinceThe Second People’s Hospital of Hunan ProvinceChangsha 410007Hunan ProvinceChina Department of Psychiatry Qingdao Mental Health CenterQingdao 266034Shandong ProvinceChina Department of Psychiatry Brain Hospital of Hunan ProvinceThe Second People’s Hospital of Hunan ProvinceChangsha 410007Hunan ProvinceChina Department of Sleep Disorders and Neurosis Brain Hospital of Hunan ProvinceThe Second People’s Hospital of Hunan ProvinceChangsha 410007Hunan ProvinceChina

BACKGROUND The expression pattern of gamma aminobutyric acid(GABA)receptor subunits are commonly altered in patients with schizophrenia,which may lead to nerve excitation/inhibition problems,affecting cognition,emotion,and *** To explore GABA receptor expression and its relationship with schizophrenia and to provide insights into more effective *** This case-control study enrolled 126 patients with schizophrenia treated at our hospital and 126 healthy volunteers who underwent physical examinations at our hospital during the same *** expression levels of the GABA receptor subunits were detected using 1H-magnetic resonance *** recognized cognitive battery tool,the MATRICS Consensus Cognitive Battery,was used to evaluate the scores for various dimensions of cognitive *** correlation between GABA receptor subunit downregulation and schizophrenia was also *** Significant differences in GABA receptor subunit levels were found between the case and control groups(P0.05).CONCLUSION Downregulation of the GABA receptor subunits is positively correlated with *** other words,when GABA receptor subunits are downregulated in patients,cognitive impairment becomes more severe.

关键词： Cognitive function Schizophrenia Downregulation Gamma-aminobutyric acid receptor subunits Correlation