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Surface growth approach for bulk reconstruction in the AdS/BCFT correspondence

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Chinese Physics C 2024年第6期48卷 222-231页

作者：方西浩陈方中孙佳睿 School of Physics and Astronomy Sun Yat-Sen UniversityGuangzhou 510275China

In this study,we extend the surface growth approach for bulk reconstruction into the Ad S spacetime with a boundary in the Ad S/BCFT *** show that the geometry in the entanglement wedge with a boundary can be constructed from the direct growth of bulk extremal surfaces layer by ***,we observe that the surface growth configuration in BCFT can be connected with the defect multi scale entanglement renormalization ansatz(MERA)tensor ***,we investigate the entanglement of purification within the surface growth process,which not only reveals more refined structure of entanglement entropy in the entanglement wedge but also suggests a selection rule for surface growth in the bulk reconstruction.

关键词： AdS/CFT correspondence gauge/gravity duality models of quantum gravity

Effect of fore/aft-loaded rotor on compressor stability under inlet circumferential distortion

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Chinese Journal of Aeronautics 2024年第5期37卷 199-213页

作者： Dakun sun Benhao GU Fangfei NING Dengke XU Xiaofeng sun School of Energy and Power Engineering Beihang UniversityBeijing 102206China Research Institute of Aero-engine Beihang UniversityBeijing 102206China

A modified small perturbation stability prediction model for axial compressors with circumferential inlet distortions is established and applied to investigate the effect of fore/aft-loaded rotor on compressor stability under circumferentially distorted inlet *** inlet total pressure distribution downstream of the distortion screen is measured in experiments and employed for simulations which are implemented via time-space spectral *** stall inception prediction results via the stability model indicate that the compressor with aft-loaded rotor not only performs better in terms of stability under uniform inlet,but also maintains a larger stability margin under circumferentially distorted *** experiments for compressors with fore-loaded and aft-loaded rotor are respectively carried *** results validate the reliability of numerical simulations and the predicted conclusion that the aft-loaded rotor is beneficial for compressor ***,the ability of the developed theoretical model for compressor stability prediction under circumferential distortions is *** addition,dynamic pressure signals at rotor tip measured in experiments illustrate that the circumferential distortion has little effect on the compressor stall pattern.

关键词： Axial compressor stability Inlet distortion Blade loading Small perturbation time-space spectral method

Multilayer polyethylene separator with enhanced thermal properties for safe lithium-ion batteries Author links open overlay panel

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Particuology 2024年第8期91卷 29-37页

作者： Ying Jiang Chen sun Feilong Dong Haiming Xie Liqun sun National&Local United Engineering Laboratory for Power Battery Department of ChemistryNortheast Normal UniversityChangchun130024China

The separator plays an important part in battery safety and *** separators are widely used in commercial Lithium-ion batteries(LIBs),owing to their excellent properties,but they suffer from serious thermal shrinkage and poor electrolyte ***,a multilayer separator(ASPESA)is developed by coating two thin layers of low-density polyethylene(LDPE)and Al_(2)O_(3)on both sides of a polyethylene membrane using a facile and environmentally friendly casting *** ASPESA separator demonstrates a shutdown function at 120℃and shows enhanced thermal stability under 185℃,with a small thermal shrinkage of 1%.Meanwhile,the LDPE and Al_(2)O_(3)layers can improve the electrolyte wettability and electrolyte uptake(407.23%).The multilayer ASPESA separator delivers an excellent cycle performance in LiFePO_(4)||Li cells with a discharge capacity of 144.5 mAh g^(-1)after 900 cycles,with a high-capacity retention of 98.9%(compared to the 5th cycle).Therefore,the multilayer ASPESA separator has great utilization potential as a high-safety separator in LIBs.

关键词： Low-density polyethylene microspheres Al_(2)O_(3)particles Thermal shutdown High safety Lithium-ionbatteries

Adaptive Event-Triggered time-Varying Output Group Formation Containment Control of Heterogeneous Multiagent Systems

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IEEE/CAA Journal of Automatica Sinica 2024年第6期11卷 1398-1409页

作者： Lihong Feng Bonan Huang Jiayue sun Qiuye sun Xiangpeng Xie College of Information Science and Engineering Northeastern UniversityShenyang 110819China College of Automation and College of Artificial Intelligence Nanjing University of Posts and TelecommunicationsNanjing 210023China IEEE

In this paper,a class of time-varying output group formation containment control problem of general linear hetero-geneous multiagent systems(MASs)is investigated under directed *** MAS is composed of a number of tracking leaders,formation leaders and followers,where two different types of leaders are used to provide reference trajectories for movement and to achieve certain formations,***,compen-sators are designed whose states are estimations of tracking lead-ers,based on which,a controller is developed for each formation leader to accomplish the expected ***,two event-triggered compensators are proposed for each follower to evalu-ate the state and formation information of the formation leaders in the same group,***,a control protocol is designed for each follower,utilizing the output information,to guide the output towards the convex hull generated by the forma-tion leaders within the ***,the triggering sequence in this paper is decomposed into two sequences,and the inter-event intervals of these two triggering conditions are provided to rule out the Zeno ***,a numerical simulation is intro-duced to confirm the validity of the proposed results.

关键词： Adaptive control event-triggered mechanisms for-mation containment(FC) heterogeneous multiagent systems time-varying group formation.

Heat Recuperation for the Self-Condensing CO_(2)Transcritical Power Cycle

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Journal of Thermal Science 2024年第5期33卷 1630-1641页

作者： PAN Lisheng SHI Weixiu sun Yin sun Yiwei WEI Xiaolin State Key Laboratory of High-temperature Gas Dynamics Institute of MechanicsChinese Academy of SciencesBeijing 100190China School of Environment and Energy Engineering Beijing University of Civil Engineering and ArchitectureBeijing 100044China

The supercritical CO_(2)Brayton cycle has potential to be used in electricity generation occasions with its advantages of high efficiency and compact *** on a so-called self-condensing CO_(2)transcritical power cycle,a model was established and four different layouts of heat recuperation process were analyzed,a without-recuperation cycle,a post-recuperation cycle,a pre-recuperation cycle and a re-recuperation *** results showed that the internal normal cycle's share of the whole cycle increases with increasing the cooling pressure and decreasing the final cooled *** load in the supercritical heater decreases with increasing the cooling *** perspective of performance,the re-recuperation cycle and the pre-recuperation cycle have similar thermal efficiency which is much higher than other two *** thermal efficiency and net power output have a maximum value with the cooling pressure,except in the condition with the final cooled temperature of 31℃.Considering both the complexity and the economy,the pre-recuperation cycle is more applicable than the other *** 35℃of the final cooled temperature,the thermal efficiency of the pre-recuperation cycle reaches the peak 0.34 with the cooling pressure of 8.4 MPa and the maximum net power output is 2355.24 kW at 8.2 MPa of the cooling pressure.

关键词： CO_(2)transcritical power cycle heat recuperation process self-condensing

MH-STRALP:A scoring system for prognostication in patients with upper gastrointestinal bleeding

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World Journal of Gastrointestinal Surgery 2024年第3期16卷 790-806页

作者： Jun-Nan Hu Fei Xu Ya-Rong Hao Chun-Yan sun Kai-Ming Wu Yong Lin Lan zhong Xin Zeng Department of Gastroenterology Shanghai East HospitalTongji University School of MedicineShanghai 200120China Department of Gastroenterology Shanghai Changzheng HospitalNavy Military Medical UniversityShanghai 200003China

BACKGROUND Upper gastrointestinal bleeding(UGIB)is a common medical emergency and early assessment of its outcomes is vital for treatment *** To develop a new scoring system to predict its *** In this retrospective study,692 patients with UGIB were enrolled from two cen-ters and divided into a training(n=591)and a validation cohort(n=101).The clinical data were collected to develop new prognostic prediction *** en-dpoint was compound outcome defined as(1)demand for emergency surgery or vascular intervention,(2)being transferred to the intensive care unit,or(3)death during *** models’predictive ability was compared with previously esta-blished scores by receiver operating characteristic(ROC)*** Totally 22.2%(131/591)patients in the training cohort and 22.8%(23/101)in the validation cohort presented poor *** on the stepwise-forward Lo-gistic regression analysis,eight predictors were integrated to determine a new post-endoscopic prognostic scoring system(MH-STRALP);a nomogram was de-termined to present the *** with the previous scores(GBS,Rock-all,ABC,AIMS65,and PNED score),MH-STRALP showed the best prognostic prediction ability with area under the ROC curves(AUROCs)of 0.899 and 0.826 in the training and validation cohorts,*** to the calibration cur-ve,decision curve analysis,and internal cross-validation,the nomogram showed good calibration ability and net clinical benefit in both *** removing the endoscopic indicators,the pre-endoscopic model(pre-MH-STRALP score)was ***,the pre-MHSTRALP score showed better predictive value(AUROCs of 0.868 and 0.767 in the training and validation cohorts,respectively)than the other pre-endoscopic *** The MH-STRALP score and pre-MH-STRALP score are simple,convenient,and accurate tools for prognosis prediction of UGIB,and may be applied for early decision on its management strategies.

关键词： Upper gastrointestinal bleeding Prognosis prediction Retrospective study Nomogram Post-endoscopic model Pre-endoscopic model

YOLOv8 for Fire and Smoke Recognition Algorithm Integrated with the Convolutional Block Attention Module

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Open Journal of Applied Sciences 2024年第1期14卷 159-170页

作者： Zhangchi Liu Risheng Zhang Hao zhong Yingjie sun College of Railway Transportation Hunan University of Technology Zhuzhou China Zhuzhou Boyan Intelligent Equipment Co. Ltd. Zhuzhou China

The complexity of fire and smoke in terms of shape, texture, and color presents significant challenges for accurate fire and smoke detection. To address this, a YOLOv8-based detection algorithm integrated with the Convolutional Block Attention Module (CBAM) has been developed. This algorithm initially employs the latest YOLOv8 for object recognition. Subsequently, the integration of CBAM enhances its feature extraction capabilities. Finally, the WIoU function is used to optimize the network’s bounding box loss, facilitating rapid convergence. Experimental validation using a smoke and fire dataset demonstrated that the proposed algorithm achieved a 2.3% increase in smoke and fire detection accuracy, surpassing other state-of-the-art methods.

关键词： Object Recognition CBAM WioU State-of-the-Art Methods

Adaptive Dead-time Modulation Scheme for Bidirectional LLC Resonant Converter in Energy Router

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CSEE Journal of Power and Energy Systems 2024年第4期10卷 1710-1721页

作者： Chenghao sun Qiuye sun Rui Wang Yuyang Li Dazhong Ma College of Information Science and Engineering Northeastern UniversityShenyang 110819China

Although the dead-time optimization design of resonant converters has been widely researched,classical design methods focus more on achieving zero-voltage switching(ZVS)*** body diode loss is always ignored,which results in low-efficiency of the converter,especially,in energy router(ER).To deal with this problem,this paper proposes an adaptive deadtime modulation scheme for bidirectional LLC resonant converters in ***,the power loss of the MOSFET is analyzed based on the ***,a novel dead-time optimization modulation principle is *** can eliminate the body diode loss of MOSFET compared with existing *** on the optimization modulation principle,this paper proposes an adaptive dead-time modulation *** this end,the converter adopting the scheme no longer needs to calculate dead-time,which simplifies the parameter design ***,this scheme enables dead-time to dynamically change with working conditions according to the dead-time optimization modulation *** these effects,the ZVS operation is achieved,and the body diode loss of MOSFET is also ***,a digital implementation method is designed to make the proposed modulation scheme have fast-transient ***,experimental results show that the proposed dead-time modulation scheme enables converters to achieve ZVS operation in all working conditions,and has higher efficiency than classical dead-time design methods.

关键词： Adaptive modulation bidirectional LLC body diode loss dead-time energy router ZVS

Exploring luminescence quenching on lanthanide-doped nanoparticles through changing the spatial distribution of sensitizer and activator

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Nano Research 2024年第5期17卷 4517-4524页

作者： Jiwei Li Yao Xie Renrui sun Junxun Zhou Lining sun Department of Chemistry College of SciencesShanghai UniversityShanghai 200444China Department of Physics College of SciencesShanghai UniversityShanghai 200444China School of Medicine Shanghai UniversityShanghai 200444China

Luminescence quench is common in overdoped upconversion *** methods have been proposed to counteract the adverse effects of concentration quenching on luminescence,but in upconversion nanoparticles that are highly doped with both sensitizers and activators,the factors that contribute to the diminishing of the emission cannot be summarized by a single ***,a core-shell design is used to spatially separate the sensitizer(Yb^(3+))and activator(Er^(3+))and to modulate the emission by changes in the distribution position as well as the concentration of the dopant ions in order to probe the factors affecting the *** the sensitizer ions are located in the core,the luminescence intensity of the nanoparticles is significantly weaker than that of the other distribution,which implies that the effect of sensitizer and activator on luminescence in the highly doped state has a different and more complex *** intensity of the emission is more affected by Yb^(3+)than Er^(3+),which includes not only the self-quenching of Yb^(3+),but also the dominance in the Yb^(3+)-Er^(3+)*** this finding may provide new ideas for revealing the reasons for the diminished luminescence of highly doped upconversion nanoparticles and thus for enhancing luminescence.

关键词： upconversion luminescence lanthanide ion core-shell nanoparticles concentration quenching cross-relaxation