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A Galaxy Image Augmentation Method Based on Few-shot Learning and Generative Adversarial Networks

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Research in Astronomy and Astrophysics 2024年第3期24卷 180-193页

作者： Yiqi Yao Jinqu zhang ping Du Shuyu Dong School of Artificial Intelligence South China Normal UniversityFoshan 528225China School of Computer Science South China Normal UniversityGuangzhou 510631China Guangdong Construction Vocational Technology Institute Guangzhou 511500China

Galaxy morphology classifications based on machine learning are a typical technique to handle enormous amounts of astronomical observation data,but the key challenge is how to provide enough training data for the machine learning *** this article proposes an image data augmentation method that combines few-shot learning and generative adversarial *** Galaxy10 DECaLs data set is selected for the experiments with consistency,variance,and augmentation effects being *** popular networks,including AlexNet,VGG,and ResNet,are used as examples to study the effectiveness of different augmentation methods on galaxy morphology *** results show that the proposed method can generate galaxy images and can be used for expanding the classification model’s training *** to comparative studies,the best enhancement effect on model performance is obtained by generating a data set that is 0.5–1 time larger than the original data ***,different augmentation strategies have considerably varied effects on different types of ***-GAN achieved the best classification performance on the ResNet network for In-between Round Smooth Galaxies and Unbarred Loose Spiral Galaxies,with F1 Scores of 89.54%and 63.18%,*** comparison reveals that various data augmentation techniques have varied effects on different categories of galaxy morphology and machine learning ***,the best augmentation strategies for each galaxy category are suggested.

关键词： techniques image processing-galaxies structure-galaxies general

Dynamic Identification and Evolution of Urban-suburban-rural Transition Zones Based on the Blender of Natural and Humanistic Factors: A Case Study of Chengdu, China

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Chinese Geographical Science 2024年第5期34卷 791-809页

作者： DENG Wei JIANG Zhenyuan zhang Shaoyao REN ping zhang Hao WANG Zhanyun The Faculty Geography Resources Science Sichuan Normal UniversityChengdu 610101China Sustainable Development Research Center of Resources and Environment in Western Sichuan Sichuan Normal UniversityChengdu 610101China Institute of Mountain Hazards and Environment Chinese Academy of SciencesChengdu 610041China

Urban-suburban-rural(U-S-R)zones exhibit distinctive transitional characteristics in interaction between human and nature.U-S-R transition zones(U-S-RTZ)are also highlighting the function diversity and landscape heterogeneity across territorial *** a super megacity in western China,Chengdu’s rapid urbanization has driven the evolution of U-S-R spaces,resulting in a sequential *** promote the high-quality spatial development of urban-rural region in a structured and efficient manner,it is essential to con-duct a scientific examination of the multidimensional interconnection within the U-S-RTZ *** proposing a novel identifica-tion method of U-S-RTZ and taking Chengdu,China as a case study,grounded in a blender of natural and humanistic factors,this study quantitatively delineated and explored the spatial evolutions of U-S-RTZ and stated the optimization orientation and sustainable devel-opment strategies of the production-living-ecological spaces along the U-S-R *** results show that:1)it is suitable for the quantitative analysis of U-S-RTZ by established three-dimensional identification system in this study.2)In 1990-2020,the urban-sub-urban transition zones(U-STZ)in Chengdu have continuously undergone a substantial increase,and the scale of the suburban-rural transition zones(S-RTZ)has continued to expand slightly,while the space of rural-ecological transition zones(R-ETZ)has noticeably compressed.3)The landuse dynamics within U-S-RTZ has gradually increased in *** main direction of landuse transition was from farmland to construction land or woodlands,with the expansion of construction land being the most significant.4)R-ETZ primarily focus on ecological functions,and there is a trade-off relationship between the production-ecological function within the S-RTZ,and in the U-STZ,production-living composite functions are *** study emphasizes the importance of elastic planning and precise governance within the U-

关键词： transition zone urban-suburban-rural zones spatial identification evolution mechanism Chengdu,China

Uniform lithium deposition induced by copper phthalocyanine additive for durable lithium anode in lithium-sulfur batteries

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Chinese Chemical Letters 2024年第5期35卷 447-452页

作者： Ting Hu Yuxuan Guo Yixuan Meng ze zhang Ji Yu Jianxin Cai Zhenyu Yang Key Laboratory of Jiangxi Province for Environment and Energy Catalysis School of Chemistry and Chemical EngineeringNanchang UniversityNanchang 330031China

Copper phthalocyanine(CuPc)is adopted as an electrolyte additive to stabilize lithium anode for lithiumsulfur(Li-S)*** with a planar molecular structure and lithiophilic N-containing group,is likely to be adsorbed on the surface of Li anode to form a coating layer,which can restrict the direct contact between Li anode and solvents,and guide the uniform deposition of Li^(+)*** Li||Li symmetric cells demonstrate a stable cycle performance,and Li||Cu cells show high Coulombic *** Li-S batteries,the formed stable solid-electrolyte interface(SEI)film containing copper sulfides can protect Li anode from the polysulfide corrosion and side reactions with the electrolyte,leading to the compact and smooth surface morphology of Li ***,the Li-S batteries with CuPc additive deliver much higher capacity,better cycle performance and rate capability as compared to the one without CuPc additive.

关键词： Copper phthalocyanine Electrolyte additive Stable SEI film Stabilized Li anode Lithium-sulfur batteries

Investigation on ignition characteristics of charring conductive polymers stimulated by electric energy

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Chinese Journal of Aeronautics 2024年第10期37卷 68-82页

作者： Zhiyuan zhang Hanyu DENG Wenhe LIAO Yantao PU ping CAO School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing 210094China Anhui Hongxing Electrical Polytron Technologies Inc. Hefei 231135China

The arc ignition based on charring conductive polymers has advantages of simple structure,low ignition power consumption and restart capacity,which bringing it broadly application prospect in hybrid propulsion system of micro/nano *** order to optimize the performance of arc ignition system,it is essential to have a deeper understanding of the ignition processes and ignition characteristics of charring conductive *** this paper,the thermal decomposition,electrical conductivity and thermal conductivity characteristics of charring conductive polymers with different conductive additives and matrix materials were comprehensively *** experimental investigation was conducted to determine the ignition behaviors and characteristics of different charring conductive polymers in a visual ignition *** experiment result showed that the ignition delay and external energy required for ignition are negatively correlated with voltage and initial temperature of the ignition grain,but positively correlated with oxidizer flow *** with charring conductive polymers containing multi-walled carbon nanotube,the ignition delay of charring conductive polymers with carbon black is significantly higher and the pyrolysis time is relatively ***,the ignition and initial flame propagation of charring conductive polymers with carbon black is more violent and more inclined to carbon particle ***,the restart characteristic of different charring conductive polymers was *** ignition delay and external energy required for ignition of different charring conductive polymers all reduced with the increasing of the number of ***,the ignition characteristics would not change a lot after repeated ignition.

关键词： Micro/nano satellite hybrid rocket motors Arc ignition Charring conductive polymer Ignition process Ignition characteristic Restart characteristic

Study on moisture absorption characteristics of glass fibrereinforced epoxy resin material for composite insulators based on the 3D-Fick model

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High Voltage 2024年第4期9卷 888-901页

作者： Yuming zhang Yunpeng Liu Sizu Hou Jianghai Geng ping Wang Hebei Provincial Key Laboratory of Power Transmission Equipment Security Defense North China Electric Power UniversityBaodingChina Hebei Key Laboratory of Power Internet of Things Technology BaodingChina

Long-term exposure to moisture leads to a gradual deterioration of performance and reduced service life of glass fibre-reinforced epoxy resin(GFRP)material in composite ***,it is necessary to analyse the moisture absorption characteristics of GFRP material and the evolution of damage to their internal interface *** absorption tests on GFRP rod material used in composite insulators to obtain their three-dimensional diffusion coefficients are *** force microscopy was then employed to obtain the composite material system's fibre/matrix interfacial phase ***,a finite element model incorporating representative volume elements with interfacial phases and a mesoscale transient moisture absorption finite element model for the composite material was ***,the moisture absorption characteristics of GFRP material and the evolution of damage to the interfacial phase under thermal-humidity cycling conditions were *** results showed that the diffusion coefficient along the fibre direction in GFRP material was higher than that in the perpendicular *** moisture diffusion finite element model,incorporating an anisotropic interfacial phase,fitted the anisotropic diffusion coefficients of GFRP material more *** moisture invaded the GFRP material,the mismatch stresses continuously increased during the moisture ***,the non-uniform arrangement of fibres resulted in uneven distribution of moistureinduced stresses inside the material,leading to higher mismatch stresses in areas with dense fibre arrangements in the *** high and low humidity cycles led to the development of micro-cracks,micro-porosity,and interface debonding along the fibre direction at the GFRP material interfaces,thereby affecting the anisotropic moisture absorption characteristics of the *** findings of this study provide valuable insights into the mechanisms underlying the

关键词： composite fibre moisture

CuO/Co3O4 Bifunctional Catalysts for Electrocatalytic5-Hydroxymethylfurfural Oxidation Coupled Cathodic Ammonia Production

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Energy & Environmental Materials 2024年第5期7卷 259-266页

作者： Li zhang Peiyue Jin ze Wu Bo Zhou Junchang Jiang Aomeng Deng Qiuyue Li Tanveer Hussain Yiqiong zhang Hanwen Liu Shuangyin Wang College of Materials Science and Engineering Changsha University of Science and Technology School of Chemical Engineering Xiangtan University State Key Laboratory of Chemo/Bio-Sensing and Chemometrics College of Chemistry and Chemical Engineering Hunan University School of Science and Technology University of New England WA School of Mines Minerals Energy and Chemical Engineering (WASMMECE) Curtin University

The electrochemical coupling of biomass oxidation and nitrogen conversion presents a potential strategy for high value-added chemicals and nitrogen cycling. Herein, in this work, CuO/Co3O4with heterogeneous interface is successfully constructed as a bifunctional catalyst for the electrooxidation of5-hydroxymethylfurfural to 2,5-furandicarboxylic acid and the electroreduction of nitrate to ammonia （NH3）. The open-circuit potential spontaneous experiment shows that more 5-hydroxymethylfurfural molecules are adsorbed in the Helmholtz layer of the CuO/Co3O4composite, which certifies that the CuO/Co3O4heterostructure is conducive to the kinetic adsorption of 5-hydroxymethylfurfural. In situ electrochemical impedance spectroscopy further shows that CuO/Co3O4has faster reaction kinetics and lower reaction potential in oxygen evolution reaction and 5-hydroxymethylfurfural electrocatalytic oxidation. Moreover, CuO/Co3O4also has a good reduction effect on NO3-. The ex-situ Raman spectroscopy shows that under the reduction potential, the metal oxide is reduced, and the generated Cu2O can be used as a new active site for the reaction to promote the electrocatalytic conversion of NO3-to NH3synthesis. This work provides valuable guidance for the synthesis of value-added chemicals by 5-hydroxymethylfurfural electrocatalytic oxidation coupled with NO3-while efficiently producing NH3.

关键词： 5-hydroxymethylfurfural oxidation ammonia production bifunctional catalyst CuO/Co3O4 electrocatalyst

Epidemiology and prognostic nomogram for locally advanced gastric signet ring cell carcinoma:A population-based study

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World Journal of Gastrointestinal Oncology 2024年第6期16卷 2610-2630页

作者： ze-Hao Yu Lei-Ming zhang Zhi-Qi Dai Meng-Na zhang Si-Ming Zheng Health Science Center The First Affiliated Hospital of Ningbo UniversityNingbo 315000Zhejiang ProvinceChina Health Science Center Ningbo UniversityNingbo 315211Zhejiang ProvinceChina College of Medicine The First Affiliated Hospital of Zhejiang UniversityHangzhou 310058Zhejiang ProvinceChina

BACKGROUND Gastric signet ring cell carcinoma(GSRC)represents a specific subtype of gastric cancer renowned for its contentious epidemiological features,treatment principles,and prognostic *** To investigate the epidemiology of GSRC and establish an improved model for predicting the prognosis of patients with locally advanced GSRC(LAGSRC)after *** The annual rates of GSRC incidence and mortality,covering the years 1975 to 2019,were extracted from the Surveillance,Epidemiology,and End Results(SEER)database to explore the temporal trends in both disease incidence and mortality rates using Joinpoint *** clinical data of 3793 postoperative LAGSRC patients were collected from the SEER database for the analysis of survival *** Cox regression model was used to explore the independent prognostic factors for overall survival(OS).The risk factors extracted were used to establish a prognostic *** The overall incidence of GSRC increased dramatically between 1975 and 1998,followed by a significant downward trend in incidence after *** recent years,there has been a similarly optimistic trend in GSRC mortality *** trend in GSRC showed discrepancies based on age and *** operating characteristic curves,calibration curves,and decision curve analysis for 1-year,3-year,and 5-year OS demonstrated the high discriminative ability and clinical utility of this *** area under the curve indicated that the performance of the new model outperformed that of the pathological staging *** The model we established can aid clinicians in the early prognostication of LAGSRC patients,resulting in improved clinical outcomes by modifying management strategies and patient health care.

关键词： Signet ring cell carcinoma Locally advanced gastric cancer Adjuvant chemotherapy Nomogram Epidemiology Overall survival

An Improved Modulation Strategy for Single-phase Three-level Neutral-point-clamped Converter in Critical Conduction Mode

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Journal of Modern Power Systems and Clean Energy 2024年第3期12卷 981-990页

作者： Ning Li Yujie Cao Xiaokang Liu Yan zhang Ruotong Wang Lin Jiang Xiao-ping zhang School of Electrical Engineering Xi’an University of TechnologyXi’anChina the Department of Electronics Information and BioengineeringPolitecnico di MilanoMilanItaly Xi’an Jiaotong University Xi’anChina the Department of Electrical Engineering and Electronics University of LiverpoolLiverpoolU.K. the Department of Electronic Electrical and Systems EngineeringUniversity of BirminghamBirminghamU.K.

Two-level totem-pole power factor correction(PFC)converters in critical conduction mode(CRM)suffer from the wide regulation range of switching ***,in highfrequency applications,the number of switching times increases,resulting in significant switching *** solve these issues,this paper proposes an improved modulation strategy for the single-phase three-level neutral-point-clamped(NPC)converter in CRM with *** optimizing the discharging strategy and switching state sequence,the switching frequency and its variation range have been efficiently *** detailed performance analysis is also presented regarding the switching frequency,the average switching times,and the effect of voltage gain.A 2 k W prototype is built to verify the effectiveness of the proposed modulation strategy and analysis *** with the totem-pole PFC converter,the switching frequency regulation range of the three-level PFC converter is reduced by 36.48%and the average switching times is reduced by 45.10%.The experimental result also shows a 1.2%higher efficiency for the three-level PFC converter in the full load range.

关键词： Critical conduction mode(CRM) on-board charger switching frequency range switching times power factor correction(PFC) three-level converter

Chemical modification of barite for improving the performance of weighting materials for water-based drilling fluids

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Petroleum Science 2024年第1期21卷 551-566页

作者： Li-Li Yang ze-Yu Liu Shi-bo Wang Xian-Bo He Guan-Cheng Jiang Jie zhang MOE Key Laboratory of Petroleum Engineering State Key Laboratory of Petroleum Resources and ProspectingChina University of Petroleum(Beijing)Changping DistrictBeijing102249China MOE Key CNPC Drilling Research Institute Changping DistrictBeijing102206China

With increasing drilling depth and large dosage of weighting materials,drilling fluids with high solid content are characterized by poor stability,high viscosity,large water loss,and thick mud cake,easier leading to reservoir damage and wellbore *** this paper,micronized barite(MB)was modified(mMB)by grafting with hydrophilic polymer onto the surface through the free radical polymerization to displace conventional API barite *** suspension stability of water-based drilling fluids(WBDFs)weighted with API barite:mMB=2:1 in 600 g was significantly enhanced compared with that with API barite/WBDFs,exhibiting the static sag factor within 0.54 and the whole stability index of *** viscosity and yield point reached the minimum,with a reduction of more than 40%compared with API barite only at the same *** multi-stage filling and dense accumulation of weighting materials and clays,filtration loss was decreased,mud cake quality was improved,and simultaneously it had great reservoir protection performance,and the permeability recovery rate reached 87%.In addition,it also effectively improved the lubricity of *** sticking coefficient of mud cake was reduced by 53.4%,and the friction coefficient was ***,mMB can serve as a versatile additive to control the density,rheology,filtration,and stability of WBDFs weighted with API barite,thus regulating comprehensive performance and achieving reservoir protection *** work opened up a new path for the productive drilling of extremely deep and intricate wells by providing an efficient method for managing the performance of high-density WBDFs.

关键词： Drilling fluids Weighting materials Filtration control Reservoir protection Stability property