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Buckling Optimization of Curved Grid Stiffeners through the Level Set Based Density Method

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Computer Modeling in Engineering & Sciences 2024年第7期140卷 711-733页

作者： zhuo Huang Ye Tian Yifan Zhang Tielin Shi qi Xia State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan430074China

Stiffened structures have great potential for improvingmechanical performance,and the study of their stability is of great interest.In this paper,the optimization of the critical buckling load factor for curved grid stiffeners is solved by using the level set based density method,where the shape and cross section(including thickness and width)of the stiffeners can be optimized simultaneously.The grid stiffeners are a combination ofmany single stiffenerswhich are projected by the corresponding level set functions.The thickness and width of each stiffener are designed to be independent variables in the projection applied to each level set function.Besides,the path of each single stiffener is described by the zero iso-contour of the level set function.All the single stiffeners are combined together by using the p-norm method to obtain the stiffener grid.The proposed method is validated by several numerical examples to optimize the critical buckling load factor.

关键词： Stiffener buckling optimization shape and cross section level set based density

Review on frost resistance and anti-clogging of pervious concrete

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Journal of Traffic and Transportation Engineering(English Edition) 2024年第3期11卷 481-496页

作者： zhuo Wang Zhichen Liu feng Zeng Kun He Shuaicheng Guo China Railway Construction Group Co. Ltd. State Key Laboratory of Bridge Safety and Resilience College of Civil Engineering Hunan University

Pervious concrete is a special type of concrete that is of high porosity and contains no or a small amount of fine aggregate, and it is an important basic material for sponge city construction. The presence of a large number of connected pores inside pervious concrete leads to a marked difference in durability failure mechanism compared with that of ordinary concrete.In this study, the frost resistance and anti-clogging of pervious concrete were introduced in detail, and the methods to improve their performance were summarized systematically. The cracking pattern of pervious concrete is influenced by geometric characteristics and three-dimensional morphological features of pores, resulting in its crack generation, development, and geometry being significantly different from those of ordinary concrete, thus leading to different freeze-thaw cycle mechanisms. In addition,due to its different pore structure compared to ordinary concrete, three types of clogging mechanisms, affecting the long-term permeability of pervious concrete were elaborated systematically(i.e., physical clogging, biological clogging, and chemical clogging). And the ways to improve the anti-clogging of pervious concrete are systematically presented from multiple perspectives. Finally, in order to broaden the engineering applications of pervious concrete, some research proposals are presented in this study.

关键词： Pervious concrete Connected pore Frost resistance Clogging mechanism

Waste to treasure:Reutilization of fluid catalytic cracking coke block as photothermal conversion material for water evaporation

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Particuology 2024年第5期88卷 62-70页

作者： Zhuwei Gao Chengxin Li Jingjing He zhuo Wang Xinyu qi Lan He Shihao Wang Zhongxin Liu School of Chemical Engineering and Technology Hainan UniversityHaikou 570228China TJ-YZ School of Network Science Haikou University of EconomicsHaikou 570203China School of Food Science and Engineering Hainan UniversityHaikou 570228China Key Laboratory of Advanced Materials of Tropical Island Resources of Ministry of Education Hainan UniversityHaikou 570228China Hainan Provincial Key Laboratory of Fine Chemicals Hainan UniversityHaikou 570228China

This study aims to analyze the coking process and propose an effective method for the reutilization of fluid catalytic cracking(FCC)coke block.Herein,we analyzed the basic characteristics and chemical composition of FCC coke blocks.The results showed that the main components were carbon,oxygen,and aluminum,accounting for 60.8%,26.6%,and 11.5%,respectively.Under the conventional catalytic cracking reaction temperature from 500°C to 600°C,the formation of the first aromatic hydrocarbon was particularly important for the formation of coke.The condensation of oil-gas-entrained catalyst particles and their heavy components was the physical cause of coking,while the dehydrogenation condensation reaction of oil-gas heavy components was the chemical factor.In addition,the membrane prepared by powdered coke had excellent photothermal conversion ability,which could be heated to more than 110°C within 360 s under two fixed light intensities.The evaporation rate of photothermal water was 5.89 kg m 2 h−1,which has great industrial application potential.These works provide a novel and effective method of separation membrane for the reutilization of FCC coke blocks.

关键词： Coking process Reutilization of FCC coke Carbonaceous deposition Membrane Photothermal conversion

Sound event localization and detection based on deep learning

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Journal of Systems Engineering and Electronics 2024年第2期35卷 294-301页

作者： ZHAO Dada DING Kai qi Xiaogang CHEN Yu feng Hailin School of Mathematics and Statistics Xidian UniversityXi’an 710071China Science and Technology on Near-Surface Detection Laboratory Wuxi 214035China

Acoustic source localization(ASL)and sound event detection(SED)are two widely pursued independent research fields.In recent years,in order to achieve a more complete spatial and temporal representation of sound field,sound event localization and detection(SELD)has become a very active research topic.This paper presents a deep learning-based multioverlapping sound event localization and detection algorithm in three-dimensional space.Log-Mel spectrum and generalized cross-correlation spectrum are joined together in channel dimension as input features.These features are classified and regressed in parallel after training by a neural network to obtain sound recognition and localization results respectively.The channel attention mechanism is also introduced in the network to selectively enhance the features containing essential information and suppress the useless features.Finally,a thourough comparison confirms the efficiency and effectiveness of the proposed SELD algorithm.Field experiments show that the proposed algorithm is robust to reverberation and environment and can achieve higher recognition and localization accuracy compared with the baseline method.

关键词： sound event localization and detection(SELD) deep learning convolutional recursive neural network(CRNN) channel attention mechanism

Hybrid pedestrian positioning system using wearable inertial sensors and ultrasonic ranging

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Defence Technology（防务技术） 2024年第3期33卷 327-338页

作者： Lin qi Yu Liu Chuanshun Gao Tao feng Yue Yu School of Communication and Information Engineering Chongqing University of Posts and TelecommunicationsChongqing 400065China Department of Land Surveying and Geo-Informatics The Hong Kong Polytechnic UniversityHong Kong 999077China

Pedestrian positioning system(PPS)using wearable inertial sensors has wide applications towards various emerging fields such as smart healthcare,emergency rescue,soldier positioning,etc.The performance of traditional PPS is limited by the cumulative error of inertial sensors,complex motion modes of pedestrians,and the low robustness of the multi-sensor collaboration structure.This paper presents a hybrid pedestrian positioning system using the combination of wearable inertial sensors and ultrasonic ranging(H-PPS).A robust two nodes integration structure is developed to adaptively combine the motion data acquired from the single waist-mounted and foot-mounted node,and enhanced by a novel ellipsoid constraint model.In addition,a deep-learning-based walking speed estimator is proposed by considering all the motion features provided by different nodes,which effectively reduces the cumulative error originating from inertial sensors.Finally,a comprehensive data and model dual-driven model is presented to effectively combine the motion data provided by different sensor nodes and walking speed estimator,and multi-level constraints are extracted to further improve the performance of the overall system.Experimental results indicate that the proposed H-PPS significantly improves the performance of the single PPS and outperforms existing algorithms in accuracy index under complex indoor scenarios.

关键词： Pedestrian positioning system Wearable inertial sensors Ultrasonic ranging Deep-learning Data and model dual-driven

Visible Light Indoor Positioning System Based on Pisarenko Harmonic Decomposition and Neural Network

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Chinese Journal of Electronics 2024年第1期33卷 195-203页

作者： Li ZHAO Yi REN qi WANG Lange DENG feng ZHANG School of Electronic Information Engineering Xi’an Technological University

Visible-light indoor positioning is a new generation of positioning technology that can be integrated into smart lighting and optical communications. The current received signal strength(RSS)-based visible-light positioning systems struggle to overcome the interferences of background and indoor-reflected noise. Meanwhile, when ensuring the lighting, it is impossible to use the superposition of each light source to accurately distinguish light source information; furthermore, it is difficult to achieve accurate positioning in complex indoor environments. This study proposes an indoor positioning method based on a combination of power spectral density detection and a neural network. The system integrates the mechanism for visible-light radiation detection with RSS theory, to build a back propagation neural network model fitting for multiple reflection channels. Different frequency signals are loaded to different light sources at the beacon end, and the characteristic frequency and power vectors are obtained at the location end using the Pisarenko harmonic decomposition method. Then, a complete fingerprint database is established to train the neural network model and conduct location tests. Finally, the location effectiveness of the proposed algorithm is verified via actual positioning experiments. The simulation results show that, when four groups of sinusoidal waves with different frequencies are superimposed with white noise, the maximum frequency error is 0.104 Hz and the maximum power error is 0.0362 W. For the measured positioning stage, a 0.8 m × 0.8 m × 0.8 m solid wood stereoscopic positioning model is constructed, and the average error is 4.28 cm. This study provides an effective method for separating multi-source signal energies, overcoming background noise, and improving indoor visible-light positioning accuracies.

关键词： Visible-light communication Indoor positioning Frequency estimation Pisarenko harmonic decomposition Back propagation neural network

Regeneration of the heart:f rom molecular mechanisms to clinical therapeutics

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Military Medical Research 2024年第1期11卷 80-97页

作者： qian-Yun Guo Jia-qi Yang Xun-Xun feng Yu-Jie Zhou Beijing Key Laboratory of Precision Medicine of Coronary Atherosclerotic Disease Beijing Institute of Heart Lung and Blood Vessel DiseaseClinical Center for Coronary Heart DiseaseDepartment of CardiologyBeijing Anzhen HospitalCapital Medical UniversityBeijing 100029China

Heart injury such as myocardial infarction leads to cardiomyocyte loss,fibrotic tissue deposition,and scar formation.These changes reduce cardiac contractility,resulting in heart failure,which causes a huge public health burden.Military personnel,compared with civilians,is exposed to more stress,a risk factor for heart diseases,making cardiovascular health management and treatment innovation an important topic for military medicine.So far,medical intervention can slow down cardiovascular disease progression,but not yet induce heart regeneration.In the past decades,studies have focused on mechanisms underlying the regenerative capability of the heart and applicable approaches to reverse heart injury.Insights have emerged from studies in animal models and early clinical trials.Clinical interventions show the potential to reduce scar formation and enhance cardiomyocyte proliferation that counteracts the pathogenesis of heart disease.In this review,we discuss the signaling events controlling the regeneration of heart tissue and summarize current therapeutic approaches to promote heart regeneration after injury.

关键词： Heart regeneration Cardiac disease Therapeutics Signaling mechanisms

General multi-attack detection for continuous-variable quantum key distribution with local local oscillator

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Chinese Physics B 2024年第5期33卷 255-262页

作者：康茁刘维琪齐锦贺晨 School of Information Science and Technology Northwest UniversityXi'an 710127China

Continuous-variable quantum key distribution with a local local oscillator(LLO CVQKD)has been extensively researched due to its simplicity and security.For practical security of an LLO CVQKD system,there are two main attack modes referred to as reference pulse attack and polarization attack presently.However,there is currently no general defense strategy against such attacks,and the security of the system needs further investigation.Here,we employ a deep learning framework called generative adversarial networks(GANs)to detect both attacks.We first analyze the data in different cases,derive a feature vector as input to a GAN model,and then show the training and testing process of the GAN model for attack classification.The proposed model has two parts,a discriminator and a generator,both of which employ a convolutional neural network(CNN)to improve accuracy.Simulation results show that the proposed scheme can detect and classify attacks without reducing the secret key rate and the maximum transmission distance.It only establishes a detection model by monitoring features of the pulse without adding additional devices.

关键词： CVQKD generative adversarial network attack classification

Fangji Fuling Decoction Alleviates Sepsis by Blocking MAPK14/FOXO3A Signaling Pathway

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Chinese Journal of Integrative Medicine 2024年第3期30卷 230-242页

作者： WANG Yi CHEN Ming-qi DAI Lin-feng ZHANG Hai-dong WANG Xing Department of Critical Care Medicine Changzhou Hospital of Traditional of Chinese Medicine Affiliated to Nanjing University of Chinese MedicineChangzhouJiangsu Province213000China Department of Critical Care Medicine Jiangsu Province Hospital of Chinese Medicine Affiliated to Nanjing University of Chinese MedicineNanjing210029China

Objective:To examine the therapeutic effect of Fangji Fuling Decoction(FFD) on sepsis through network pharmacological analysis combined with in vitro and in vivo experiments.Methods:A sepsis mouse model was constructed through intraperitoneal injection of 20 mg/kg lipopolysaccharide(LPS).RAW264.7 cells were stimulated by 250 ng/m L LPS to establish an in vitro cell model.Network pharmacology analysis identified the key molecular pathway associated with FFD in sepsis.Through ectopic expression and depletion experiments,the effect of FFD on multiple organ damage in septic mice,as well as on cell proliferation and apoptosis in relation to the mitogen-activated protein kinase 14/Forkhead Box O 3A(MAPK14/FOXO3A) signaling pathway,was analyzed.Results:FFD reduced organ damage and inflammation in LPS-induced septic mice and suppressed LPS-induced macrophage apoptosis and inflammation in vitro(P<0.05).Network pharmacology analysis showed that FFD could regulate the MAPK14/FOXO signaling pathway during sepsis.As confirmed by in vitro cell experiments,FFD inhibited the MAPK14 signaling pathway or FOXO3A expression to relieve LPS-induced macrophage apoptosis and inflammation(P<0.05).Furthermore,FFD inhibited the MAPK14/FOXO3A signaling pathway to inhibit LPS-induced macrophage apoptosis in the lung tissue of septic mice(P<0.05).Conclusion:FFD could ameliorate the LPS-induced inflammatory response in septic mice by inhibiting the MAPK14/FOXO3A signaling pathway.

关键词： sepsis Fangji Fuling Decoction mitogen-activated protein kinase 14/Forkhead Box O 3A signaling pathway inflammatory response apoptosis lung injury Chinese medicine