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Joint Active and Passive Beamforming Design in Intelligent Reflecting Surface(IRS)-Assisted Covert Communications:A Multi-Agent DRL Approach

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China Communications 2024年第9期21卷 11-26页

作者： gao ang Ren Xiaoyu Deng Bin Sun Xinshun Zhang Jiankang School of Electronic Information Northwestern Polytechnical UniversityXi’an 710072China Key Laboratory of Near Ground Detection and Perception Technology Wuxi 214035China Department of Computing and Informatics Bournemouth UniversityUK

Intelligent Reflecting Surface(IRS),with the potential capability to reconstruct the electromagnetic propagation environment,evolves a new IRSassisted covert communications paradigm to eliminate the negligible detection of malicious eavesdroppers by coherently beaming the scattered signals and suppressing the signals ***,when multiple IRSs are involved,accurate channel estimation is still a challenge due to the extra hardware complexity and communication *** the crossinterference caused by massive reflecting paths,it is hard to obtain the close-formed solution for the optimization of covert *** this basis,the paper improves a heterogeneous multi-agent deep deterministic policy gradient(MADDPG)approach for the joint active and passive beamforming(Joint A&P BF)optimization without the channel estimation,where the base station(BS)and multiple IRSs are taken as different types of agents and learn to enhance the covert spectrum efficiency(CSE)*** to the‘centralized training and distributed execution’feature of MADDPG,each agent can execute the active or passive beamforming independently based on its partial observation without referring to *** results demonstrate that the proposed deep reinforcement learning(DRL)approach could not only obtain a preferable CSE of legitimate users and a low detection of probability(LPD)of warden,but also alleviate the communication overhead and simplify the IRSs deployment.

关键词： covert communications deep reinforcement learning intelligent reflecting surface

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A Scenario-classification Hybrid-based Banding Method for Power Transfer Limits of Critical Inter-corridors

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Journal of Modern Power Systems and Clean Energy 2024年第2期12卷 547-560页

作者： Lidong Yi Maosheng Ding Jili Wang gao Qiu Fei Xue Ji'ang Liu Yuxiong Huang Gengfeng Li Junyong Liu State Grid Ningxia Electric Power Co. Ltd.YinchuanChinaand M.Ding is also with State Grid Ningxia Electric Power Research InstituteYinchuanChina Northwest Branch State Grid Corporation of ChinaXi’anChina School of Electrical Engineering Sichuan UniversityChengduChina State Grid Ningxia Electric Power Research Institute Yinchuan YinchuanChina School of Electrical Engineering Xi’an Jiaotong UniversityXi’anChina IEEE

To secure power system operations,practical dispatches in industries place a steady power transfer limit on critical inter-corridors,rather than high-dimensional and strong nonlinear stability ***,computational complexities lead to over-conservative pre-settings of transfer limit,which further induce undesirable and non-technical congestion of power *** conquer this barrier,a scenario-classification hybrid-based banding method is proposed.A cluster technique is adopted to separate similarities from historical and generated operating condition *** a practical rule,transfer limits are approximated for each operating ***,toward an interpretable online transfer limit decision,costsensitive learning is applied to identify cluster affiliation to assign a transfer limit for a given *** this stage,critical variables that affect the transfer limit are also picked out via mean impact *** enables us to construct low-complexity and dispatcher-friendly rules for fast determination of transfer *** numerical case studies on the IEEE 39-bus system and a real-world regional power system in China illustrate the effectiveness and conservativeness of the proposed method.

关键词： Transfer limit transfer capability power transfer inter-corridor cluster cost-sensitive learning banding power system operation

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Flexible polydimethylsiloxane pressure sensor with micro-pyramid structures and embedded silver nanowires:A novel application in urinary flow measurement

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Nanotechnology and Precision Engineering 2024年第3期7卷 1-12页

作者： Ben-Song Wang ang gao Song-Wei Huang Qi-Hong Ning Cheng Zhou Qi-Xiang Song Da-XiangCui School of Electronic Information and Electrical Engineering Shanghai Jiao Tong UniversityShanghai 200240China Department of Urology Renji HospitalSchool of MedicineShanghai Jiao Tong UniversityShanghai 200240China

Flexible pressure sensors are lightweight and highly sensitive,making them suitable for use in small portable devices to achieve precise measurements of tiny *** article introduces a low-cost and easy-fabrication strategy for piezoresistive flexible pressure *** embedding silver nanowires into a polydimethylsiloxane layer with micro-pyramids on its surface,a flexible pressure sensor is created that can detect low pressure (17.3 Pa) with fast response (<20 ms) and high sensitivity (69.6 mA kPa-1).Furthermore,the pressure sensor exhibits a sensitive and stable response to a small amount of water flowing on its *** this basis,the flexible pressure sensor is innovatively combined with a micro-rotor to fabricate a novel urinary flow-rate meter (uroflowmeter),and results from a simulated human urination experiment show that the uroflowmeter accurately captured all the essential shape characteristics that were present in the pump-simulated urination *** ahead,this research provides a new reference for using flexible pressure sensors in urinary flow-rate monitoring.

关键词： Flexible pressure sensor Silver nanowires Portable device Uroﬂowmeter Healthcare

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Segregation of Mg-6Gd alloy under natural convection:From macro solute distribution to micro dendrite growth

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China Foundry 2024年第5期21卷 613-624页

作者： Hong-xu Chen ang Zhang Hao Li Yu gao Yu-hong Cui Guang-sheng Huang Bin Jiang Fu-sheng Pan National Engineering Research Center for Magnesium Alloys National Key Laboratory of Advanced Casting TechnologiesCollege of Materials Science and EngineeringChongqing UniversityChongqing 400044China

Segregation is a serious defect in alloy ingots which severely deteriorates materials *** segregation defect in Mg-6Gd alloy is studied by coupling macro thermal-solutal-convection transport and micro dendrite *** macroscopic fluid dynamics and mass transfer equations are resolved to forecast the segregation behavior under conditions of continuous temperature variation during the solidification *** numerical model is validated by testing double-diffusive natural convection in a closed square cavity.A phase field model is then applied to simulate the micro dendrite growth,using macro undercooling and liquid flow velocity as boundary *** show that the multiscale segregation behavior,including macro solute distribution and micro dendritic morphology,is strongly dependent on the temperature condition and the liquid convection,which provides guidance for reducing and eliminating the segregation defect.

关键词： magnesium alloy segregation numerical simulation phase-field simulation multiscale

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Targeting tumour-osteoclast interactions:a trigger-explosion system to combat bone metastasis

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Biomaterials Translational 2024年第3期5卷 328-330页

作者： ang gao Huaiyu Wang Center for Human Tissues and Organs Degeneration Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenGuangdong ProvinceChina

Cancer remains one of the leading causes of death worldwide,and tumour metastasis is responsible for more than 90%of cancer deaths.1,2 Bone is recognised as the most common site for metastasis of numerous malignancies,especially breast and prostate cancer.3,4 As a highly dynamic compartment,the bone microenvironment not only facilitates primary metastasis but also enhances secondary metastasis to organs,such as the brain,liver,and lung,liver,and brain.5-7 Therefore,effectively preventing critical bone metastasis is pivotal for impeding systemic tumour spread.

关键词： metastasis organs death

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Cationic ordering transition in oxygen-redox layered oxide cathodes

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Carbon Energy 2024年第1期6卷 197-206页

作者： Xinyan Li ang gao Qinghua Zhang Hao Yu Pengxiang Ji Dongdong Xiao Xuefeng Wang Dong Su Xiaohui Rong Xiqian Yu Hong Li Yong-Sheng Hu Lin Gu Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijingChina College of Materials Science and Opto-Electronic Technology University of Chinese Academy of SciencesBeijingChina Beijing National Center for Electron Microscopy and Laboratory of Advanced Materials School of Materials Science and EngineeringTsinghua UniversityBeijingChina Beijing Advanced Innovation Center for Materials Genome Engineering Huairou DivisionInstitute of PhysicsChinese Academy of SciencesBeijingChina

Understanding the structural origin of the competition between oxygen 2p and transition-metal 3d orbitals in oxygen-redox(OR)layered oxides is eminently desirable for exploring reversible and high-energy-density Li/Na-ion ***,we reveal the correlation between cationic ordering transition and OR degradation in ribbon-ordered P3-Na_(0.6)Li_(0.2)Mn_(0.8)O_(2) via in situ structural *** two different voltage windows,the OR capacity can be improved approximately twofold when suppressing the in-plane cationic ordering *** find that the intralayer cationic migration is promoted by electrochemical reduction from Mn^(4+)to Jahn–Teller Mn^(3+)and the concomitant NaO_(6) stacking transformation from triangular prisms to octahedra,resulting in the loss of ribbon ordering and electrochemical ***-principles calculations reveal that Mn^(4+)/Mn^(3+)charge ordering and alignment of the degenerate eg orbital induce lattice-level collective Jahn–Teller distortion,which favors intralayer Mn-ion migration and thereby accelerates OR *** findings unravel the relationship between in-plane cationic ordering and OR reversibility and highlight the importance of superstructure protection for the rational design of reversible OR-active layered oxide cathodes.

关键词： cationic ordering layered oxide cathodes oxygen redox sodium-ion batteries

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NiS ultrafine nanorod with translational and rotational symmetry

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National Science Review 2024年第7期11卷 218-225页

作者： Jianxin Kang Qi Hu Ruixuan Zhang ang gao Zhongning Huang Ziming Su Ke Pei Qinghua Zhang Li-Min Liu Renchao Che Lin Gu Er-Jia Guo Lin Guo School of Chemistry Beihang University Laboratory of Advanced Materials Shanghai Key Lab of Molecular Catalysis and Innovative Materials Academy for Engineering&Technology Fudan University Zhejiang Laboratory Beijing National Center for Electron Microscopy and Laboratory of Advanced Materials School of Materials Science and Engineering Tsinghua University Beijing National Laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of Sciences School of Physics Beihang University

Anisotropy is a significant and prevalent characteristic of materials, conferring orientation-dependent properties, meaning that the creation of original symmetry enables key functionality that is not found in nature. Even with the advancements in atomic machining, synthesis of separated symmetry in different directions within a single structure remains an extraordinary challenge. Here, we successfully fabricate NiS ultrafine nanorods with separated symmetry along two directions. The atomic structure of the nanorod exhibits rotational symmetry in the radial direction, while its axial direction is characterized by divergent translational symmetry, surpassing the conventional crystalline structures known to date. It does not fit the traditional description of the space group and the point group in three dimensions, so we define it as a new structure in which translational symmetry and rotational symmetry are separated. Further corroborating the atomic symmetric separation in the electronic structure, we observed the combination of stripe and vortex magnetic domains in a single nanorod with different directions, in accordance with the atomic *** manipulation of nanostructure at the atomic level introduces a novel approach to regulate new properties finely, leading to the proposal of new nanotechnology mechanisms.

关键词： separated symmetry NiS anisotropy structure atomic machining magnetic domain

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Preliminary safety analysis for heavy water-moderated molten salt reactor

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Nuclear Science and Techniques 2024年第6期35卷 202-217页

作者： gao-ang Wen Jian-Hui Wu Chun-Yan Zou Xiang-Zhou Cai Jin-Gen Chen Man Bao College of Science University of Shanghai for Science and TechnologyShanghai 200093China Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China

The heavy water-moderated molten salt reactor(HWMSR)is a newly proposed reactor concept,in which heavy water is adopted as the moderator and molten salt dissolved with fissile and fertile elements is used as the *** arising from graphite in traditional molten salt reactors,including the positive temperature coefficient and management of highly radio-active spent graphite waste,can be addressed using the *** now,research on the HWMSR has been centered on the core design and nuclear fuel cycle to explore the viability of the HWMSR and its advantages in fuel ***,the core safety of the HWMSR has not been extensively ***,we evaluate typical accidents in a small modular HWMSR,including fuel salt inlet temperature overcooling and overheating accidents,fuel salt inlet flow rate decrease,heavy water inlet temperature overcooling accidents,and heavy water inlet mass flow rate decrease accidents,based on a neutronics and thermal-hydraulics coupled *** results demonstrated that the core maintained safety during the investigated accidents.

关键词： Heavy water-moderated molten salt reactor Neutronics and thermal-hydraulics coupling Transient analysis Accident analysis

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Efficacy and safety of PD-1 blockade plus long-course chemoradiotherapy in locally advanced rectal cancer(NECTAR):a multi-center phase 2 study

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Signal Transduction and Targeted Therapy 2024年第4期9卷 1721-1729页

作者： Zhengyang Yang Jiale gao Jianyong Zheng Jiagang Han ang Li Gang Liu Yi Sun Jie Zhang Guangyong Chen Rui Xu Xiao Zhang Yishan Liu Zhigang Bai Wei Deng Wei He Hongwei Yao Zhongtao Zhang Department of General Surgery Beijing Friendship HospitalCapital Medical UniversityState Key Lab of Digestive HealthNational Clinical Research Center for Digestive DiseasesBeijingChina Department of Gastrointestinal Surgery The First Affiliated Hospital of Air Force Medical UniversityXi'anChina Department of General Surgery Beijing Chaoyang HospitalCapital Medical UniversityBeijingChina Department of General Surgery Beijing Xuanwu HospitalCapital Medical UniversityBeijingChina Department of General Surgery Tianjin Medical University General HospitalTianjinChina Department of Anorectal Tianjin People's HospitalTianjinChina Department of Radiology Beijing Friendship Hospital Capital Medical UniversityBeijingChina Department of Pathology Beijing Friendship HospitalCapital Medical UniversityBeijingChina Department of Thoracic Surgery/Institute of Thoracic Oncology West China HospitalSichuan UniversityChengduChina

Adding PD-1 blockade in the neoadjuvant regimens for locally advanced rectal cancer(LARC)patients with microsatellite stable(MsS)/mismatch repair-proficient(pMMR)tumors is an attractive,but debatable *** phase 2,multicenter,prospective,single-arm study enrolled patients from 6 centers from June 2021 to November *** advanced rectal cancer(LARC,cT_(3-4a)N_(0)M_(0) and cT_(1-4a)N_(1-2)M_(0))patients aged≥18 years with the distance from distal border of tumor to anal verge≤10 cm(identified by Magnetic Resonance Imaging)were qualifed for *** patients received long-course radiotherapy(50 Gy/25 fractions,2 Gy/fraction,5 days/week)and three 21-day cycles capecitabine(850-1000 mg/m2,bid,po,day1-14)and three 21-day cycles tislelizumab(200 mg,***,day8)as *** mesorectal excision(TME)was 6-12 weeks after the end of radiotherapy to achieve radical resection.A total of 50 patients were enrolled in this *** pathological complete response rate was 40.0%[20/50,95%confidence interval(CI):27.61-53.82%],while 15(30.0%,95%CI:19.1-43.75%),9(18.0%,95%CI:9.77-30.8%),2(4.0%,95%CI:1.10-13.46%)patients respectively achieved grade 1,2,and 3 tumor ***-related adverse events(TRAEs)occurred in 28(56.0%)LARC patients,including 26(52.0%)with grade I-II and 2(4.0%)with grade II(1 with grade 3 immune-related colitis and 1 with grade 3 rash).PD-1 blockade plus long-course chemoradiotherapy(CRT)showed promising therapeutic effects according to pathological complete response rate and is well-tolerated in LARC patients.A larger randomized controlled study is desired to further validate the above findings.

关键词： rectal cancer phase

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High-density lipoprotein regulates angiogenesis by affecting autophagy via miRNA-181a-5p

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Science China(Life Sciences) 2024年第2期67卷 286-300页

作者： Bi-ang Kang Hua-Ming Li Ya-Ting Chen Meng-Jie Deng Yan Li Yue-Ming Peng Jian-Jun gao Zhi-Wei Mo Jia-Guo Zhou Zhi-Jun Ou Jing-Song Ou Division of Cardiac Surgery Cardiovascular Diseases InstituteThe First Affiliated HospitalSun Yat-sen UniversityGuangzhou 510080China National-Guangdong Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases Guangzhou 510080China NHC key Laboratory of Assisted Circulation(Sun Yat-sen University) Guangzhou 510080China Guangdong Provincial Engineering and Technology Center for Diagnosis and Treatment of Vascular Diseases Guangzhou 510080China Division of Vascular Surgery The First Affiliated HospitalSun Yat-sen UniversityGuangzhou 510080China Department of Pharmacology Cardiac and Cerebral Vascular Research CenterZhongshan School of MedicineSun Yat-sen UniversityGuangzhou 510080China Division of Hypertension and Vascular Diseases Department of CardiologyCardiovascular Diseases InstituteThe First Affiliated HospitalSun Yat-sen UniversityGuangzhou 510080China Guangdong Provincial Key Laboratory of Brain Function and Disease Zhongshan School of MedicineSun Yat-sen UniversityGuangzhou 510080China

We previously demonstrated that normal high-density lipoprotein(nHDL)can promote angiogenesis,whereas HDL from patients with coronary artery disease(d HDL)is dysfunctional and impairs *** plays a critical role in angiogenesis,and HDL regulates ***,it is unclear whether n HDL and d HDL regulate angiogenesis by affecting *** cells(ECs)were treated with n HDL and d HDL with or without an autophagy ***,endothelial nitric oxide synthase(e NOS)expression,miRNA expression,nitric oxide(NO)production,superoxide anion(O2^(·-))generation,EC migration,and tube formation were evaluated.n HDL suppressed the expression of miR-181a-5p,which promotes autophagy and the expression of e NOS,resulting in NO production and the inhibition of O2^(·-)generation,and ultimately increasing in EC migration and tube formation.d HDL showed opposite effects compared to n HDL and ultimately inhibited EC migration and tube *** found that autophagy-related protein 5(ATG5)was a direct target of ***5 silencing or miR-181a-5p mimic inhibited n HDL-induced autophagy,e NOS expression,NO production,EC migration,tube formation,and enhanced O2^(·-)generation,whereas overexpression of ATG5 or miR-181a-5p inhibitor reversed the above effects of d ***5 expression and angiogenesis were decreased in the ischemic lower limbs of hypercholesterolemic low-density lipoprotein receptor null(LDLr^(-/-))mice when compared to C57BL/6 ***5 overexpression improved angiogenesis in ischemic hypercholesterolemic LDLr^(-/-)*** together,nHDL was able to stimulate autophagy by suppressing miR-181a-5p,subsequently increasing e NOS expression,which generated NO and promoted *** contrast,d HDL inhibited angiogenesis,at least partially,by increasing miR-181a-5p expression,which decreased autophagy and e NOS expression,resulting in a decrease in NO production and an increase in O2^(·-)*** findings reveal a nov

关键词： high-density lipoprotein angiogenesis autophagy ATG5 miRNA endothelial nitric oxide synthase

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