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Nano Research 2024年第3期17卷 2070-2078页

作者： Wenhao Liang Juntao Wu shan Zhang Pei-yan zhao yi Cong Yongqiang Guo Guang-Sheng Wang Key Laboratory of Bioinspired Smart Interfacial Science and Technology of Ministry of Education School of ChemistryBeihang UniversityBeijing 100191China

With the rapid development of wireless communication technology and electronic devices,the issue of electromagnetic interference(EMI)is becoming increasingly *** a new and flexible electromagnetic interference shielding material has become a challenging ***,a sandwich-structured EMI shielding composite film was prepared using electrospinning and vacuum filtration *** this process,a porous MXene was synthesized through a reaction with cobalt acetate and served as the intermediate layer in the composite film to shield electromagnetic *** electrospun polyimide(PI)fibers were used as the top and bottom layers of the composite film,which can protect the porous MXene from *** lightweight and flexible composite film integrates electromagnetic interference shielding and thermal insulation capabilities,showing excellent comprehensive *** composite film achieves an EMI shielding effectiveness of 48.8 dB in X-band(8.2–12.4 GHz),and absolute shielding effectiveness of the composite film reached a satisfying 4142.43(dB·cm^(2))/*** to the design of a multi-layer porous structure,the density of the composite film is 0.65 g/***,the thermal conductivity of the film is 0.042 W/(m·K)due to the clamping of electrospun PI fibers,showing excellent thermal insulation ***,the composite film exhibits excellent high and low-temperature *** summary,this work provides a feasible strategy for preparing a lightweight polymer-based EMI shielding film.

关键词： porous MXene polyimide electromagnetic interference shielding thermal insulation

Recent research progress in the mechanism and suppression of fusion welding-induced liquation cracking of nickel based superalloys

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International Journal of Minerals,Metallurgy and Materials 2024年第5期31卷 1072-1088页

作者： Zongli yi Jiguo shan Yue zhao Zhenlin Zhang Aiping Wu Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China College of Engineering China Agricultural UniversityBeijing 100091China State Key Laboratory of Clean and Efficient Turbomachinery Power Equipment Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China Key Laboratory for Advanced Materials Processing Technology Ministry of EducationBeijing 100084China School of Material Science and Engineering Southwest Jiaotong UniversityChengdu 610031China

Nickel-based superalloys are extensively used in the crucial hot-section components of industrial gas turbines,aeronautics,and astronautics because of their excellent mechanical properties and corrosion resistance at high *** welding serves as an effective means for joining and repairing these alloys;however,fusion welding-induced liquation cracking has been a challenging *** paper comprehensively reviewed recent liquation cracking,discussing the formation mechanisms,cracking criteria,and *** recent investigations,regulating material composition,changing the preweld heat treatment of the base metal,optimizing the welding process parameters,and applying auxiliary control methods are effective strategies for mitigating *** promote the application of nickel-based superalloys,further research on the combination impact of multiple elements on cracking prevention and specific quantitative criteria for liquation cracking is necessary.

关键词： nickel-based superalloy fusion welding liquation cracking cracking mechanism cracking suppression

Radar false alarm plots elimination based on multi-feature extraction and classification

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The Journal of China Universities of Posts and Telecommunications 2024年第1期31卷 83-92页

作者： Cheng yi zhao yan yin Peiwen School of Control Science and Engineering Tiangong UniversityTianjin 300387China Tianjin Key Laboratory of Intelligent Control of Electrical Equipment Tianjin 300387China

Caused by the environment clutter,the radar false alarm plots are *** false alarm points has always been a key issue in Radar plots *** this paper,a radar false alarm plots elimination method based on multi-feature extraction and classification is proposed to effectively eliminate false alarm ***,the density based spatial clustering of applications with noise(DBSCAN)algorithm is used to cluster the radar echo data processed by constant false-alarm rate(CFAR).The multi-features including the scale features,time domain features and transform domain features are ***,a feature evaluation method combining pearson correlation coefficient(PCC)and entropy weight method(EWM)is proposed to evaluate interrelation among features,effective feature combination sets are selected as inputs of the ***,False alarm plots classified as clutters are *** experimental results show that proposed method can eliminate about 90%false alarm plots with less target loss rate.

关键词： radar plots elimination density based spatial clustering of applications with noise multi-feature extraction classifier

Carbon efficiency modeling and optimization of solar-powered cellular networks

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Science China(Information Sciences) 2024年第5期67卷 228-243页

作者： Yuxi zhao Xiaohu GE Wen yan Tao HAN yi ZHONG School of Electronic Information and Communications Huazhong University of Science and Technology Huawei Technology Co. Ltd.

As wireless communication traffic experiences rapid growth, the carbon emissions caused by the communication industry are also on the rise. To achieve “carbon neutrality”, researchers are considering the use of renewable energy sources to power cellular networks, thereby reducing carbon emissions. However, a challenge arises when using renewable energy, specifically owing to the unpredictable nature of both the energy consumption of the cellular network and the power generation from renewable sources. This inconsistency results in low renewable energy utilization and reduced carbon efficiency. Herein, we construct a carbon efficiency model of solar-powered cellular networks using practical data from solar radiation. We propose a mechanism that alternately optimizes the performance of the renewable energy network and the cellular network. This approach is based on convex optimization theory and the Dinkelback algorithm, and it leads to the design of a carbon efficiency optimization algorithm. This algorithm aims to improve the carbon efficiency of cellular networks and reduce their carbon emissions. Simulation results demonstrate that our optimization scheme yields a maximum improvement of 2.56 × 108bps/g in the carbon efficiency of the cellular network as compared to conventional power allocation schemes such as the traditional water filling method and heuristic energy sharing and charge/discharge algorithms.

关键词： cellular networks renewable energy carbon efficiency convex optimization theory dinkelbach

Tuning interface mechanism of FeCo alloy embedded N,S-codoped carbon substrate for rechargeable Zn-air battery

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Journal of Energy Chemistry 2024年第6期93卷 400-410,I0010页

作者： Hui Chang Lulu zhao shan zhao Zong-Lin Liu Peng-Fei Wang ying Xie Ting-Feng yi School of Materials Science and Engineering Northeastern UniversityShenyang 110819LiaoningChina Key Laboratory of Functional Inorganic Material Chemistry Ministry of EducationSchool of Chemistry and Materials ScienceHeilongjiang UniversityHarbin 150080HeilongjiangChina Key Laboratory of Dielectric and Electrolyte Functional Material Hebei Province School of Resources and MaterialsNortheastern University at QinhuangdaoQinhuangdao 066004HebeiChina

The interface mechanism between catalyst and carbon substrate has been the focus of *** this paper,the FeCo alloy embedded N,S co-doped carbon substrate bifunctional catalyst(FeCo/S-NC)is obtained by a simple one-step pyrolysis *** experimental results and density functional theory(DFT)calculation show that the formation of FeCo alloy is conducive to promoting electron transfer,and the introduction of S atom can enhance the interaction between FeCo alloy and carbon substrate,thus inhibiting the migration and agglomeration of particles on the surface of carbon *** FeCo/SNC catalysts show outstanding performance for oxygen reduction reaction(ORR)and oxygen evolution reaction(OER).FeCo/S-NC shows a high half-wave potential(E_(1/2)=0.8823 V)for ORR and a low overpotential at 10 mA cm^(-2)(E_(j=10)=299 mV)for *** addition,compared with Pt/C+RuO_(2) assembled Zn-air battery(ZAB),the FeCo/S-NC assembled ZAB exhibits a larger power density(198.8 mW cm^(-2)),a higher specific capacity(786.1 mA h g_(zn)~(-1)),and ultra-stable cycle *** results confirm that the optimized composition and the interfacial interaction between catalyst and carbon substrate synergistically enhance the electrochemical performance.

关键词： FeCo alloy N S co-doped carbon DFT calculation Zn-air batteries Interfacial interaction

Effi cacy of partial and complete resuscitative endovascular balloon occlusion of the aorta in the hemorrhagic shock model of liver injury

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World Journal of Emergency Medicine 2024年第1期15卷 10-15页

作者： yi shan.yan. zhao Chengcheng Li Jianxin Gao Guogeng Song Tanshi Li Department of Emergency Medicine Chinese PLA Medical SchoolBeijing 100853China Department of Emergency Medicine the Sixth Medical Center of PLA General HospitalBeijing 100048China Department of Emergency Medicine School of MedicineSouth China University of TechnologyGuangzhou 510006China Department of Emergency Medicine the First Medical Center of PLA General HospitalBeijing 100853China

BACKGROUND:Resuscitative endovascular balloon occlusion of the aorta(REBOA)can temporarily control traumatic ***,its prolonged use potentially leads to ischemia-reperfusion injury(IRI).Partial REBOA(pREBOA)can alleviate ischemic burden;however,its security and eff ectiveness prior to operative hemorrhage control remains ***,we aimed to estimate the effi cacy of pREBOA in a swine model of liver injury using an experimental sliding-chamber ballistic ***:Twenty Landrace pigs were randomized into control(no aortic occlusion)(n=5),intervention with complete REBOA(cREBOA)(n=5),continuous pREBOA(C-pREBOA)(n=5),and sequential pREBOA(S-pREBOA)(n=5)*** the cREBOA and C-pREBOA groups,the balloon was inflated for 60 *** hemodynamic and laboratory values were compared at various observation time *** samples immediately after animal euthanasia from the myocardium,liver,kidneys,and duodenum were collected for histological assessment using hematoxylin and eosin ***:Compared with the control group,the survival rate of the REBOA groups was prominently improved(all P<0.05).The total volume of blood loss was markedly lower in the cREBOA group(493.14±127.31 mL)compared with other groups(P<0.01).The pH was significantly lower at 180 min in the cREBOA and S-pREBOA groups(P<0.05).At 120 min,the S-pREBOA group showed higher alanine aminotransferase(P<0.05)but lower blood urea nitrogen compared with the cREBOA group(P<0.05).CONCLUSION:In this trauma model with liver injury,a 60-minute pREBOA resulted in improved survival rate and was effective in maintaining reliable aortic pressure,despite persistent *** tolerance time for aortic occlusion in Zone I for non-compressible torso hemorrhage was feasible with both continuous partial and sequential partial measures,and the significant improvement in the severity of acidosis and distal organ injury was observed in the sequential pREBOA.

关键词： Non-compressible torso hemorrhage Liver injury Ischemia-reperfusion injury Resuscitative endovascular balloon occlusion of the aorta

Neural stem cells promote neuroplasticity: a promising therapeutic strategy for the treatment of Alzheimer’s disease

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Neural Regeneration Research 2024年第3期19卷 619-628页

作者： Jun Chang Yujiao Li Xiaoqian shan Xi Chen Xuhe yan Jianwei Liu Lan zhao First Teaching Hospital of Tianjin University of Traditional Chinese Medicine TianjinChina National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion TianjinChina Tianjin University of Traditional Chinese Medicine TianjinChina

Recent studies have demonstrated that neuroplasticity,such as synaptic plasticity and neurogenesis,exists throughout the normal lifespan but declines with age and is significantly impaired in individuals with Alzheimer’s ***,promoting neuroplasticity may represent an effective strategy with which Alzheimer’s disease can be *** to their significant ability to self-renew,differentiate,and migrate,neural stem cells play an essential role in reversing synaptic and neuronal damage,reducing the pathology of Alzheimer’s disease,including amyloid-β,tau protein,and neuroinflammation,and secreting neurotrophic factors and growth factors that are related to *** events can promote synaptic plasticity and neurogenesis to repair the microenvironment of the mammalian ***,neural stem cells are considered to represent a potential regenerative therapy with which to improve Alzheimer’s disease and other neurodegenerative *** this review,we discuss how neural stem cells regulate neuroplasticity and optimize their effects to enhance their potential for treating Alzheimer’s disease in the clinic.

关键词： Alzheimer’s disease amyloid-β cell therapy extracellular vesicle neural stem cell synaptic plasticity tau

Regioselective C-C bond cleavage/aminocarbonylation cascade under copper catalysis

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Science China Chemistry 2024年第11期67卷 3798-3806页

作者： Qi-Chao shan.yan.zhao Yong Wu Hong-Fei Liu Xin-Hua Duan Li-Na Guo Department of Chemistry School of Chemistry Energy Research Center of Energy Storage Materials and Devices Ministry of EducationXi'an Jiaotong University State Key Laboratory of Applied Organic Chemistry Lanzhou University

A regioselective C-C bond cleavage/aminocarbonylation cascade is presented. In recent years, tremendous progress has been made in the alkoxyl radical-mediated C-C bond cleavage of unstrained monocarbocycles. In contrast, the deconstruction and functionalization of bicyclic skeletons has been less developed and has mainly focused on the ring expansion process. Inspired by the aromatization-driven C-C bond cleavage, here we demonstrate a ring-opening/aminocarbonylation cascade under copper catalysis, in which the formation of a stable γ-lactam or succinimide skeleton reverses the selectivity of C-C cleavage. Remarkably, the photo and thermal assistance is not required when the succinimide skeleton is formed during the ring opening process. DFT calculations revealed that this unexpected ring-opening process is thermodynamically and kinetically favourable.

关键词： C-C bond cleavage controllable regioselectivity aminocarbonylation bicyclic alkoxy radical

Bolstering the Mechanical Robustness of Supramolecular Polymer Network by Mechanical Bond

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Chinese Journal of Polymer Science 2024年第10期42卷 1536-1544,I0012页

作者： Yuan-Hao Wang Jing-Xi Deng Jun zhao yi Ding Li yang zhao-Ming Zhang Xu-Zhou yan School of Chemistry and Chemical Engineering Shanghai Jiao Tong UniversityShanghai200240China Frontiers Science Center for Transformative Molecules Shanghai Jiao Tong UniversityShanghai200240China

Supramolecular polymer networks(SPNs)are celebrated for their dynamic nature,yet they often exhibit inadequate mechanical *** far,the quest to bolster the mechanical resilience of SPNs while preserving their dynamic character presents a formidable ***,we introduce[2]rotaxane into SPN to serve as another cross-link,which could effectively enhance the mechanical robustness of the polymer network without losing the dynamic *** with SPN,the dually cross-linked network(DPN)demonstrates superior breaking strength,Young’s modulus,puncture force and toughness,underscoring its superior ***,the cyclic tensile tests reveal that the energy dissipation capacity of DPN rivals,and in some cases surpasses,that of SPN,owing to the efficient energy dissipation pathway facilitated by[2]*** addition,benefiting from stable topological structure of[2]rotaxane,DPN exhibits accelerated recovery from deformation,indicating superior elasticity compared to *** strategy elevates the performance of SPNs across multiple metrics,presenting a promising avenue for the development of high-performance dynamic materials.

关键词： Rotaxane cross-links Dually cross-linked network Supramolecular polymer network Host-guest recognition Dynamic materials

Prevalence of hypertension and its associations with body composition across Chinese and American children and adolescents

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World Journal of Pediatrics 2024年第4期20卷 392-403页

作者： Li-Wang Gao yi-Wen Huang Hong Cheng Xi Wang Hong-Bo Dong Pei Xiao yin-Kun yan Xin-ying shan Xiao-Yuan zhao Jie Mi Center for Non-Communicable Disease Management Beijing Children’s HospitalCapital Medical UniversityNational Center for Children’s HealthNo.56 Nanlishi RoadXicheng DistrictBeijing100045China Department of Epidemiology Capital Institute of PediatricsNo.2 Yabao RoadChaoyang DistrictBeijing100020China Key Laboratory of Major Diseases in Children Ministry of EducationBeijingChina

Background The age of onset of hypertension(HTN)is decreasing,and obesity is a significant risk *** prevalence and racial disparities in pediatric HTN and the association between body composition and blood pressure are insufficiently *** study aimed to evaluate the prevalence of HTN in Chinese and American children and adolescents and to assess the relationship between various body composition indices and *** Seven thousand,five hundred and seventy-three Chinese and 6239 American children and adolescents aged 8–18 years from the 2013–2015 China Child and Adolescent Cardiovascular Health study and the 2011–2018 National Health and Nutrition Examination Surveys were *** pressure and body composition(fat and muscle)were measured by trained *** crude prevalence and age-standardized prevalence rate(ASPR)of primary HTN and its subtypes[isolated systolic hypertension(ISH)and isolated diastolic hypertension(IDH)]were calculated based on 2017 American Academy of Pediatrics ***-adjusted linear regression coefficients and odds ratios(ORs)were calculated to assess the associations of body composition indicators with HTN,ISH and *** The ASPR of HTN was 18.5%in China(CN)and 4.6%in the United States(US),whereas the obesity prevalence was 7.4%and 18.6%,and the population attributable risk of HTN caused by overweight and obesity was higher in the US than in *** fat mass,muscle mass and body fat percentage mass were associated with a higher risk of HTN in both *** percent of muscle body mass had a protective effect on HTN and ISH in both countries[HTN(CN:OR=0.83,95%CI=0.78–0.88;US:OR=0.72,95%CI=0.64–0.81);ISH(CN:OR=0.87,95%CI=0.80–0.94;US:OR=0.71,95%CI=0.62–0.81)],and the protective effect was more common among children and adolescents with high levels of physical *** The burden of HTN in Chinese children and adolescents was substantial and much greater than that in the US,and th

关键词： Body composition Children and adolescents China Child and Adolescent Cardiovascular Health Hypertension National Health and Nutrition Examination Surveys