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Space debris environment engineering model 2019:Algorithms improvement and comparison with ORDEM 3.1 and MASTER-8

Chinese Journal of Aeronautics 2024年第5期37卷 392-409页

作者： Yuyan LIU Runqiang CHI Baojun PANG HU Diqi Wuxiong CAO Dongfang WANG School of Astronautics Harbin Institute of TechnologyHarbin 150001China College of Safety Science&Engineering Civil Aviation University of ChinaTianjin 300300China

As an essential tool for realistic description of the current or future debris environment,the Space Debris Environment Engineering Model(SDEEM)has been developed to provide support for risk assessment of *** contrast with SDEEM2015,SDEEM2019,the latest version,extends the orbital range from the Low Earth Orbit(LEO)to Geosynchronous Orbit(GEO)for the years *** this paper,improved modeling algorithms used by SDEEM2019 in propagating simulation,spatial density distribution,and spacecraft flux evaluation are *** debris fluxes of SDEEM2019 are compared with those of three typical models,i.e.,SDEEM2015,Orbital Debris Engineering Model 3.1(ORDEM 3.1),and Meteoroid and Space Debris Terrestrial Environment Reference(MASTER-8),in terms of two assessment *** orbital cases,including the Geostationary Transfer Orbit(GTO),Sun-Synchronous Orbit(SSO)and International Space Station(ISS)orbit,are selected for the spacecraft assessment mode,and the LEO region is selected for the spatial density assessment *** analysis indicates that compared with previous algorithms,the variable step-size orbital propagating algorithm based on semi-major axis control is more precise,the spatial density algorithm based on the second zonal harmonic of the non-spherical Earth gravity(J_(2))is more applicable,and the result of the position-centered spacecraft flux algorithm is more *** comparison shows that SDEEM2019 and MASTER-8 have consistent trends due to similar modeling processes,while the differences between SDEEM2019 and ORDEM 3.1 are mainly caused by different modeling approaches for uncatalogued debris.

关键词： SDEEM2019 Space debris propagating algorithm Spatial density algorithm ORDEM 3.1 MASTER-8

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A review on the evaluation models and impact factors of greenhouse gas emissions from municipal solid waste management processes

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Environmental science and Pollution Research 2024年第19期31卷 27531-27553页

作者： Yang, Guodong Liu, Mengdan Gao, Yuchen Han, Siyu Meng, Fanzhi Ju, Tongyao Jiang, Jianguo School of Environment Harbin Institute of Technology Harbin150001 China School of Environment Tsinghua University Beijing100084 China School of Environmental Science and Engineering Southern University of Science and Technology Shenzhen518055 China

The total amount of global municipal solid waste (MSW) will reach 3.5 billion tons by 2050, thereby bringing tremendous environmental pressure, especially global warming. Large amounts of greenhouse gases (GHGs) have been released during MSW management (MSWM). Accounting for GHG emissions is a prerequisite for providing recommendations on appropriate treatment options to mitigate emissions from MSWM systems. There are many methods involved in estimating emissions. This paper summarizes the computing models commonly used in each process of the integrated MSWM system and emphasizes the influence of parameters and other factors. Compared with other disposal methods, landfilling has the highest emissions, commonly estimated using first-order decay (FOD) methods. Emission reduction can be realized through waste to energy (WtE) and resource recovery measures. IPCC is commonly used for calculating direct emissions, while LCA-based models can calculate emissions including upstream and downstream processes, whose results depend on assumptions and system boundaries. The estimation results of models vary greatly and are difficult to compare with each other. Besides, large gaps exist between the default emission factors (EFs) provided by models and those F measured in specific facilities. These findings provide a systematic view for a bettering understanding of MSW emissions as well as the estimating methods and also reveal the key points that need be developed in the future. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.

关键词： Municipal solid waste

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Age estimation from facial images based on Gabor feature fusion and the CIASO-SA algorithm

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CAAI Transactions on Intelligence technology 2023年第2期8卷 518-531页

作者： Di Lu Dapeng Wang Kaiyu Zhang Xiangyuan Zeng School of Measurement and Communication Engineering Harbin University of Science and TechnologyHarbinChina Cheriton School of Computer Science University of WaterlooWaterlooOntarioCanada

Aiming at the problem of long time-consuming and low accuracy of existing age estimation approaches,a new age estimation method using Gabor feature fusion,and an improved atomic search algorithm for feature selection is ***,texture features of five scales and eight directions in the face region are extracted by Gabor wavelet *** statistical histogram is introduced to encode and fuse the directional index with the largest feature value on Gabor ***,a new hybrid feature selection algorithm chaotic improved atom search optimisation with simulated annealing(CIASO-SA)is presented,which is based on an improved atomic search algorithm and the simulated annealing ***,the CIASO-SA algorithm introduces a chaos mechanism during atomic initialisation,significantly improving the convergence speed and accuracy of the ***,a support vector machine(SVM)is used to get classification results of the age *** verify the performance of the proposed algorithm,face images with three resolutions in the Adience dataset are *** the Gabor real part fusion feature at 48�48 resolution,the average accuracy and 1-off accuracy of age classification exhibit a maximum of 60.4%and 85.9%,*** results prove the superiority of the proposed algorithm over the state-of-the-art methods,which is of great referential value for application to the mobile terminals.

关键词： age estimation atom search algorithm feature selection Gabor feature simulated annealing

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A double-layer radiative cooling coating that utilizes the refractive index difference between layers to achieve extremely high solar reflectivity

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science China(Technological sciences) 2024年第10期67卷 3182-3189页

作者： WANG FuQiang LI ChunZhe YANG ZhenNing XIE WeiXin LI Xiang XU ZengHui YAN YuYing CHENG ZiMing School of Energy Science and Engineering Harbin Institute of TechnologyHarbin 150001China School of New Energy Harbin Institute of Technology at WeihaiWeihai 264209China China Construction Eco-Environmental Protection Technology Co. Ltd.Suzhou 215123China Faculty of Engineering University of NottinghamNottingham NG72RDUK

Passive daytime radiative cooling(PDRC)technology has great potential in reducing cooling energy *** order to further improve the spectral performance of PDRC coatings,current researchers mostly focus on the selection and size design of functional particles,while ignoring the optical properties enhancement effect caused by the interlayer *** this study,based on the principle that the refractive index difference between layers enhanced the backscattering performance of the solar spectrum,we proposed and manufactured a double-layer PDRC coating with polyvinylidene difluoride(PVDF)as the filmforming material in the upper layer and polydimethylsiloxane(PDMS)as the film-forming material in the lower layer,both filled with Al_(2)O_(3) and SiO_(2) *** double-layer PDRC coating exhibited excellent spectral performance that a high solar reflectivity of 98%and an emissivity of 0.95 at the“atmospheric window”*** comparison,the solar spectrum reflectivity of the single-layer PDRC coatings based on PVDF and PDMS of the same thickness was 95%and 94.7%,*** tests showed that the PDRC coating achieved a temperature decrease of up to 7.1℃ under direct sunlight at noon *** addition,the PDRC coating had excellent weather resistance,water resistance,and other basic *** article opens up a new idea and provides methodological guidance for the design of double-layer PDRC coatings.

关键词： double-layer radiative cooling coating spectral modulation interlayer refractive index solar energy radiative transfer

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Polystyrene nanoplastics induce glycolipid metabolism disorder via NF-κB and MAPK signaling pathway in mice

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Journal of Environmental sciences 2024年第3期137卷 553-566页

作者： Xingpei Fan Xiaoyan Li Jiaxin Li Yuxia Zhang Xiangjuan Wei Hailong Hu Boya Zhang Haining Du Meimei Zhao Ruijiao Zhu Daqian Yang Yuri Oh Ning Gu School of Life Science and Technology Harbin Institute of TechnologyHarbin 150001China State Key Laboratory of Urban Water Resource and Environment Harbin Institute of TechnologyHarbin 150006China Department of Medicine Renal Electrolyte and Hypertension DivisionDepartment of GeneticsPerelman School of MedicineUniversity of PennsylvaniaPhiladelphia 19104USA Faculty of Education Wakayama UniversityWakayama 640-8441Japan

Nanoplastics-induced developmental and reproductive toxicity,neurotoxicity and immunotoxicity are a focus of widespread ***,the effects of nanoplastics(NPs)on glycolipid metabolism and the precise underlying mechanisms are unclear at ***,we showed that oral administration of polystyrene nanoparticles(PS-NPs)disrupts glycolipid metabolism,with reactive oxygen species(ROS)identified as a potential key signaling *** PS-NPs treatment,excessive production of ROS induced the infammatory response and activated the antioxidant pathway through nuclear factor-erythroid factor 2-related factor *** activation of nuclear factor-κB(NFκB)signaling pathway induced the phosphorylation of the mitogen-activated protein kinases(MAPK)signaling pathway,which induced the activation of extracellular regulated kinases(ERK)and *** activation of the MAPK signaling proteins induced high continued phosphorylation of insulin receptor substrate-1,in turn,leading to decreased protein kinase B(Akt)activity,which weakened the sensitivity of liver cells to insulin signals and induced insulin *** parallel,phosphorylation of Akt led to loss of control of Fo XO1,a key gene of gluconeogenesis,activating transcription of glucose-6-phosphatase(G6PC)and phosphoenolpyruvate carboxykinase(PEPCK)in a manner dependent on PGC1α.Moreover,the activated ERK promoted lipid accumulation through ERK-PPARγ***,sterol regulatory element-binding protein-1 and levels of its downstream lipogenic enzymes,ACC-1,were *** treatment with the antioxidant resveratrol,PS-NPs-induced glucose and lipid metabolic disorders were improved by inhibiting ROS-induced activation of NFκB and MAPK signaling pathway in *** on above,PS-NPs exposure disrupts glycolipid metabolism in mice,with ROS identified as a potential key signaling molecule.

关键词： Nanoplastics Resveratrol Hyperglycemia Lipid metabolism Infammatory response Reactive oxygen species(ROS)

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Boundary-aware Contrastive Learning for Semi-supervised Nuclei Instance Segmentation 7

Boundary-aware Contrastive Learning for Semi-supervised Nucl...

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7th International Conference on Medical Imaging with Deep Learning, MIDL 2024

作者： Zhang, Ye Wang, Ziyue Wang, Yifeng Bian, Hao Cai, Linghan Li, Hengrui Zhang, Lingbo Zhang, Yongbing School of Computer Science and Technology Harbin Institute of Technology 518055 China School of Science Harbin Institute of Technology 518055 China Tsinghua Shenzhen International Graduate School Tsinghua University 518071 China Faculty of Computing Harbin Institute of Technology 150001 China

Semi-supervised segmentation methods have demonstrated promising results in natural scenarios, providing a solution to reduce dependency on manual annotation. However, these methods face significant challenges when directly applied to pathological images due to the subtle color differences between nuclei and tissues, as well as the significant morphological variations among nuclei. Consequently, the generated pseudo-labels often contain much noise, especially at the nuclei boundaries. To address the above problem, this paper proposes a boundary-aware contrastive learning network to denoise the boundary noise in a semi-supervised nuclei segmentation task. The model has two key designs: a low-resolution denoising (LRD) module and a cross-RoI contrastive learning (CRC) module. The LRD improves the smoothness of the nuclei boundary by pseudo-labels denoising, and the CRC enhances the discrimination between foreground and background by boundary feature contrastive learning. We conduct extensive experiments to demonstrate the superiority of our proposed method over existing semi-supervised instance segmentation methods. © 2024 CC-BY 4.0, Y. Zhang, Z. Wang1, Y. Wang2, H. Bian3, L. Cai1, H. Li4, L. Zhang3 & Y. Zhang1.

关键词： Contrastive Learning

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Quantum search with prior knowledge

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science China(Information sciences) 2024年第9期67卷 321-329页

作者： Xiaoyu HE Xiaoming SUN Jialing ZHANG State Key Lab of Processors Institute of Computing Technology Chinese Academy of Sciences School of Computer Science and Technology University of Chinese Academy of Sciences

The combination of contextual side information and search is a powerful paradigm in the scope of artificial intelligence. The prior knowledge enables the identification of possible solutions but may be imperfect. Contextual information can arise naturally, for example in game AI where prior knowledge is used to bias move decisions. In this work we investigate the problem of taking quantum advantage of contextual information, especially searching with prior knowledge. We propose a new generalization of Grover's search algorithm that achieves the optimal expected success probability of finding the solution if the number of queries is fixed. Experiments on small-scale quantum circuits verify the advantage of our algorithm. Since contextual information exists widely, our method has wide applications. We take game tree search as an example.

关键词： quantum computing quantum search quantum query algorithm prior knowledge

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The preparation, microstructure, and performance of MoAlB-Si ceramic sintered from combustion-synthesized powder

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Ceramics International 2025年第16期51卷 21800-21809页

作者： Yu, Wanjun Ding, Qizhang Li, Xiangming Zhang, Enliang Han, Wenbo Zheng, Yongting Qi, Yushi School of Environment and Materials Engineering Yantai University Yantai264005 China School of Materials Science and Engineering Harbin Institute of Technology Weihai264209 China National Key Laboratory of Science and Technology on Advanced Composites in Special Environments and Center for Composite Materials and Structures Harbin Institute of Technology Harbin150080 China

To streamline the preparation process and improve the performance of the MoAlB phase, the technical potential of an ultra-fast combustion synthesis followed by hot pressing to prepare the MoAlB–Si ceramic was investigated. During the combustion process, the Si atoms occupied the Al positions, which forms a Mo(Al,Si)B solid solution phase. Si doping resulted in the effective grain refinement of the hot-pressed MoAlB-Si ceramic. The grain-refined and solid-solution-strengthened MoAlB-Si ceramic exhibits excellent mechanical properties with a compressive strength of 2.63 GPa, flexural strength of 650 MPa, fracture toughness of 7.26 MPa m1/2, and Vickers hardness of 13.32 GPa. At elevated temperatures, a newly formed oxidation-derived dense and continuous layer on the surface prevents the inward diffusion of oxygen and the volatilisation of oxidation products, indicating good oxidation resistance of the MoAlB-Si ceramic. © 2025 Elsevier Ltd and Techna Group S.r.l.

关键词： Compressive strength

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Contrastive Augmented Graph2Graph Memory Interaction for Few Shot Continual Learning

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IEEE Transactions on Circuits and Systems for Video technology 2025年第6期35卷 5805-5820页

作者： Qi, Biqing Gao, Junqi Chen, Xinquan Li, Dong Liu, Jianxing Wu, Ligang Zhou, Bowen Tsinghua University Department of Electronic Engineering Beijing China Shanghai Artificial Intelligence Laboratory Shanghai China Harbin Institute of Technology Department of Control Science and Engineering Harbin China Harbin Institute of Technology School of Mathematics Harbin China

Few-Shot Class-Incremental Learning (FSCIL) has gained considerable attention in recent years for its pivotal role in addressing continuously arriving classes. However, it encounters additional challenges. The scarcity of samples in new sessions intensifies overfitting, causing incompatibility between the output features of new and old classes, thereby escalating catastrophic forgetting. A prevalent strategy involves mitigating catastrophic forgetting through the Explicit Memory (EM), which comprise of class prototypes. However, current EM-based methods retrieves memory globally by performing Vector-to-Vector (V2V) interaction between features corresponding to the input and prototypes stored in EM, neglecting the geometric structure of local features. This hinders the accurate modeling of their positional relationships. To incorporate information of local geometric structure, we extend the V2V interaction to Graph-to-Graph (G2G) interaction. For enhancing local structures for better G2G alignment and the prevention of local feature collapse, we propose the Local Graph Preservation (LGP) mechanism. Additionally, to address sample scarcity in classes from new sessions, the Contrast-Augmented G2G (CAG2G) is introduced to promote the aggregation of same class features thus helps few-shot learning. Extensive comparisons on CIFAR100, CUB200, and the challenging ImageNet-R dataset demonstrate the superiority of our method over existing methods. © 1991-2012 IEEE.

关键词： Prototypes Adaptation models Power capacitors Feature extraction Data models Accuracy Vectors Training Incremental learning Overfitting

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Influence of the position relationship between the cathode and magnetic separatrix on the discharge process of a Hall thruster

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Plasma science and technology 2024年第1期26卷 74-81页

作者：曹希峰麻洪宁夏国俊刘辉赵方舟王宇航陈巨辉 School of Mechanical and Power Engineering Harbin University of Science and TechnologyHarbin 150001People’s Republic of China Shanghai Institute of Satellite Engineering Shanghai 20040People’s Republic of China Lab of Plasma Propulsion Harbin Institute of TechnologyHarbin 150001People’s Republic of China

Previous studies have shown that there is an obvious coupling relationship between the installation location of the external cathode and the magnetic separatrix in the plume region of a Hall *** this paper,the particle-in-cell simulation method is used to compare the thruster discharge process under the conditions of different position relationships between the cathode and the magnetic *** comparing the distribution of electron conduction,potential,plasma density and other microscopic parameters,we try to explain the formation mechanism of the discharge *** simulation results show that the cathode inside and outside the magnetic separatrix has a significant effect on the distribution of potential and plasma *** the cathode is located on the outer side of the magnetic separatrix,the potential above the plume region is relatively low,and there is a strong potential gradient above the plume *** potential gradient is more conducive to the radial diffusion of ions above the plume,which is the main reason for the strong divergence of the *** distribution of ion density is also consistent with the distribution of *** the cathode is located on the outer side of the magnetic separatrix,the radial diffusion of ions in the plume region is ***,by comparing the results of electron conduction,it is found that the traiectories of electrons emitted from the cathode are significantly different between the inner and outer sides of the magnetic *** is mainly because the electrons are affected by the magnetic mirror effect of the magnetic tip,which makes it difficult for the electrons to move across the magnetic *** is the main reason for the difference in potential *** this paper,the simulation results of macroscopic parameters under several conditions are also compared,and they are consistent with the experimental *** cathode is located on the inner side of the ma

关键词： Hall thruster cathode magnetic separatrix

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