检索结果-南通市图书馆

Unstructured Road Extraction in UAV Images based on Lightweight Model

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2024年第2期37卷 372-384页

作者： Di Zhang Qichao An Xiaoxue feng Ronghua Liu Jun han feng Pan School of Automation Beijing Institute of TechnologyBeijing 100081China Tianjin Institute of Maritime Navigation Instruments Tianjin 300130China The 716th Research Institute of China Shipbuilding Group Co. LtdJiangsu 222061China

There is no unified planning standard for unstructured roads,and the morphological structures of these roads are complex and varied.It is important to maintain a balance between accuracy and speed for unstructured road extraction models.Unstructured road extraction algorithms based on deep learning have problems such as high model complexity,high computational cost,and the inability to adapt to current edge computing devices.Therefore,it is best to use lightweight network models.Considering the need for lightweight models and the characteristics of unstructured roads with different pattern shapes,such as blocks and strips,a TMB(Triple Multi-Block)feature extraction module is proposed,and the overall structure of the TMBNet network is described.The TMB module was compared with SS-nbt,Non-bottleneck-1D,and other modules via experiments.The feasibility and effectiveness of the TMB module design were proven through experiments and visualizations.The comparison experiment,using multiple convolution kernel categories,proved that the TMB module can improve the segmentation accuracy of the network.The comparison with different semantic segmentation networks demonstrates that the TMBNet network has advantages in terms of unstructured road extraction.

关键词： Unstructured road Lightweight model Triple Multi-Block(TMB) Semantic segmentation net

Metagenomic insights into microorganisms and antibiotic resistance genes of waste antibiotic fermentation residues along production,storage and treatment processes

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第2期136卷 45-55页

作者： Ziming han Xiao Luan Haodi feng Yanqin Deng Min Yang Yu Zhang State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery Beijing 100085China Wuhan Agricultural Inspection Center Wuhan 430016China University of Chinese Academy of Sciences Beijing 100049China

Antibiotic fermentation residue(AFR)is nutrient-rich solid waste generated from fermentative antibiotic production process.It is demonstrated that AFR contains high-concentration of remaining antibiotics,and thus may promote antibiotic resistance development in receiving environment or feeding farmed animals.However,the dominate microorganisms and antibiotic resistance genes(ARGs)in AFRs have not been adequately explored,hampering understanding on the potential antibiotic resistance risk development caused by AFRs.Herein,seven kinds of representative AFRs along their production,storage,and treatment processes were collected,and multiple methods including amplicon sequencing,metagenomic sequencing,and bioinformatic approaches were adopted to explore the biological characteristics of AFRs.As expected,antibiotic fermentation producer was found as the predominant species in raw AFRs,which were collected at the outlet of fermentation tanks.However,except for producer species,more environment-derived species persisted in stored AFRs,which were temporarily stored at a semi-open space.Lactobacillus genus,classified as Firmicutes phylum and Bacilli class,became predominant bacterial taxa in stored AFRs,which might attribute to its tolerance to high concentration of antibiotics.Results from metagenomic sequencing together with assembly and binning approaches showed that these newly-colonizing species(e.g.,Lactobacillus genus)tended to carry ARGs conferring resistance to the remaining antibiotic.However,after thermal treatment,remaining antibiotic could be efficiently removed from AFRs,and microorganisms together with DNA could be strongly destroyed.In sum,the main risk from the AFRs was the remaining antibiotic,while environment-derived bacteria which tolerate extreme environment,survived in ARFs with high content antibiotics,and may carry ARGs.Thus,hydrothermal or other harmless treatment technologies are recommended to remove antibiotic content and inactivate bacteria before recycling of AFRs in pharmaceutical industry.

关键词： Pharmaceutical manufacturing Antibiotic mycelia residue Antibiotic resistance bacteria Thermal treatment Solid waste

Study on the Precursor Phase Composition of Fused Iron Catalyst for Fischer-Tropsch Synthesis

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2005年第10期16卷 1393-1396页

作者： Ju Li SHEN Hua Zhang LIU Xiao nian LI Weng feng han Yi Fan ZHENG Catalysis Institute of Zhejiang University of Technology State Key Laboratory Breeding Base of Green-Chemistry Synthesis Technology Hangzhou 310014

The effect of the precursor composition of fused iron catalyst on the performance of Fischer-Tropsch synthesis was investigated. XRD, BET and CO2 adsorption experiments were carried out to provide better insight into the relationship therein. The results showed that the selectivity of C5＋ hydrocarbon products was dependent on the mole ratio of Fe^2＋/Fe^3＋, which was represented by a hump-shaped curve. Catalysts with precursors containing Fe3O4 phase favored the magnetite spinal formation during F-T reaction, while Fe（1-x）O-based catalysts were more likely to favor the formation and growth of the iron carbide crystals.

关键词： Fischer-Tropsch synthesis fused iron catalyst precursor selectivity.

Variability of the Pacific subtropical cells under global warming in CMIP6 models

在线全文

学校读者我要写书评

暂无评论

Journal of Oceanology and Limnology 2024年第1期42卷 24-40页

作者： Xue han Junqiao feng Yunlong LU Dunxin HU Key Laboratory of Ocean Circulation and Waves Chinese Academy of SciencesQingdao 266071China Institute of Oceanology Chinese Academy of SciencesQingdao 266071China University of Chinese Academy of Sciences Beijing 100049China Center for Ocean Mega-Science Chinese Academy of SciencesQingdao 266071China Laboratory for Ocean Dynamics and Climate Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao 266237China

The Pacific subtropical cells(STCs)are shallow meridional overturning circulations connecting the tropics and subtropics,and are assumed to be an important driver of the tropical Pacific decadal variability.The variability of STCs under global warming is investigated using multimodal outputs from the latest phase of the Coupled Model Inter-comparison Project(CMIP6)and ocean reanalysis products.Firstly,the volume transport diagnostic analysis is employed to evaluate how coupled models and ocean reanalysis products reproduce interior STC transport.The variation of heat transport by the interior STC under the high-emissions warming scenarios is also analyzed.The results show that the multimodal-mean linear trends of the interior STC transport along 9°S and 9°N are-0.02 Sv/a and 0.04 Sv/a under global warming,respectively,which is mainly due to the combined effect of the strengthened upper oceanic stratification and the weakening of wind field.There is a compensation relationship between the interior STC and the western boundary transport in the future climate,and the compensation relationship of 9°S is more significant than that of 9°N.In addition,compared with ocean reanalysis products,the coupled models tend to underestimate the variability of the interior STC transport convergence,and thus may lose some sea surface temperature(SST)driving force,which may be the reason for the low STC-SST correlation simulated by the model.The future scenario simulation shows that the heat transport of interior STC is weakened under global warming,with a general agreement across models.

关键词： interior subtropical cell(STC) global warming Coupled Model Inter-comparison Project(CMIP6) western boundary transport

Melt flow,heat transfer and solidification in a flexible thin slab continuous casting mold with vertical-combined electromagnetic braking

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research(International) 2024年第2期31卷 401-415页

作者： Lin Xu Ze-feng han Christian Karcher En-gang Wang Key Laboratory of Electromagnetic Processing of Materials(Ministry of Education) Northeastern UniversityShenyang110819LiaoningChina Key Laboratory of Liaoning Province for Clean Combustion Power Generation and Heating Technology Shenyang Institute of EngineeringShenyang110136LiaoningChina Institute of Thermodynamics and Fluid Mechanics Technische Universität IlmenauIlmenau98684Germany

During continuous casting of steel slabs,the application of electromagnetic braking technology(EMBr)provides an effective tool to influence solidification by controlling the pattern of melt flow in the mold.Thus,the quality of the final product can be improved considerably.A new electromagnetic braking(EMBr)method,named vertical-combined electromagnetic braking(VC-EMBr),is proposed to be applied to a flexible thin slab casting(FTSC)mold.To evaluate the beneficial effects of the VC-EMBr,the melt flow,heat transfer,and solidification processes in the FTSC mold are studied by means of numerical simulations.In detail,a Reynolds-averaged Navier–Stokes turbulence model together with an enthalpy-porosity approach was used.The numerical findings are compared with respective simulations using the traditional Ruler-EMBr.The results demonstrate that the application of the VC-EMBr contributes significantly to preventing relative slab defects.In contrast to the Ruler-EMBr,the additional vertical magnetic poles of the VC-EMBr preferentially suppress the direct impact of jet flow on the narrow face of FSTC mold and considerably diminish the level fluctuation near the meniscus region.For instance,by applying a magnetic flux density of 0.3 T,the maximum amplitude of meniscus deflection reduces by about 80%.Moreover,the braking effect of the VC-EMBr effectively improves the homogeneity of temperature distribution in the upper recirculation region and increases the solidified shell thickness along the casting direction.On this basis,the newly proposed VC-EMBr shows a beneficial effect in preventing relative slab defects for FTSC thin slab continuous casting.

关键词： Electromagnetic braking Mold Melt flow Heat transfer Solidification

Ballistic target recognition based on multiple data representations and deep-learning algorithms

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第6期37卷 167-181页

作者： Lixun han Cunqian feng Xiaowei HU Sisan HE Xuguang XU Air and Missile Defense College Air Force Engineering UniversityXi’an 710051China College of Information and Communication National University of Defense TechnologyWuhan 430010China

Target recognition is a significant part of a Ballistic Missile Defense System(BMDS).However,most existing ballistic target recognition methods overlook the impact of data representation on recognition outcomes.This paper focuses on systematically investigating the influences of three novel data representations in the Range-Doppler(RD)domain.Initially,the Radar Cross Section(RCS)and micro-Doppler(m-D)characteristics of a cone-shaped ballistic target are analyzed.Then,three different data representations are proposed:RD data,RD sequence tensor data,and RD trajectory data.To accommodate various data inputs,deep-learning models are designed,including a two-Dimensional Residual Dense Network(2D RDN),a three-Dimensional Residual Dense Network-Gated Recurrent Unit(3D RDN-GRU),and a Dynamic Trajectory Recognition Network(DTRN).Finally,an Electromagnetic(EM)computation dataset is collected to verify the performances of the networks.A broad range of experimental results demonstrates the effectiveness of the proposed framework.Moreover,several key parameters of the proposed networks and datasets are extensively studied in this research.

关键词： Ballistic target Micro-Doppler Deep learning Range-Doppler Radar target recognition

The hydrophobic cluster on the surface of protein is the key structural basis for the SDS-resistance of chondroitinase VhChlABC

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Marine Life Science & Technology 2024年第1期6卷 93-101页

作者： Juanjuan Su Hao Wu Chengying Yin fengchao Zhang feng han Wengong Yu School of Medicine and Pharmacy Ocean University of ChinaQingdao 266003China Laboratory for Marine Drugs and Bioproducts Qingdao Marine Science and Technology CenterQingdao 266237China Key Laboratory of Marine Drugs Ministry of EducationQingdao 266003China Shandong Provincial Key Laboratory of Glycoscience and Glycoengineering Qingdao 266003China

The application of chondroitinase requires consideration of the complex microenvironment of the target.Our previous research reported a marine-derived sodium dodecyl sulfate(SDS)-resistant chondroitinase VhChlABC.This study further investigated the mechanism of VhChlABC resistance to SDS.Focusing on the hydrophobic cluster on its strong hydrophilic surface,it was found that the reduction of hydrophobicity of surface residues Ala181,Met182,Met183,Ala184,Val185,and Ile305 significantly reduced the SDS resistance and stability.Molecular dynamics(MD)simulation and molecular docking analysis showed that I305G had more conformational flexibility around residue 305 than wild type(WT),which was more conducive to SDS insertion and binding.The affinity of A181G,M182A,M183A,V185A and I305G to SDS was significantly higher than that of WT.In conclusion,the surface hydrophobic microenvironment composed of six residues was the structural basis for SDS resistance.This feature could prevent the binding of SDS and the destruction of hydrophobic packaging by increasing the rigid conformation of protein and reducing the binding force of SDS-protein.The study provides a new idea for the rational design of SDS-resistant proteins and may further promote chondroitinase research in the targeted therapy of lung diseases under the pressure of pulmonary surfactant.

关键词： Hydrophobic cluster Protein surface SDS-resistance Chondroitinase

Dynamic simulation analysis of molten salt reactor-coupled air-steam combined cycle power generation system

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第2期35卷 222-233页

作者： Jing-Lei Huang Guo-Bin Jia Li-feng han Wen-Qian Liu Li Huang Zheng-han Yang Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China

A nonlinear dynamic simulation model based on coordinated control of speed and flow rate for the molten salt reactor and combined cycle systems is proposed here to ensure the coordination and stability between the molten salt reactor and power system.This model considers the impact of thermal properties of fluid variation on accuracy and has been validated with Simulink.This study reveals the capability of the control system to compensate for anomalous situations and maintain shaft stability in the event of perturbations occurring in high-temperature molten salt tank outlet parameters.Meanwhile,the control system’s impact on the system’s dynamic characteristics under molten salt disturbance is also analyzed.The results reveal that after the disturbance occurs,the controlled system benefits from the action of the control,and the overshoot and disturbance amplitude are positively correlated,while the system power and frequency eventually return to the initial values.This simulation model provides a basis for utilizing molten salt reactors for power generation and maintaining grid stability.

关键词： Molten salt reactor Combined cycle Dynamic characteristic Control

Innovative construction of macroporous–mesoporous structured spherical alumina and its hydrothermal stability

在线全文

学校读者我要写书评

暂无评论

Particuology 2024年第7期90卷 429-435页

作者： Yufan Mo Chunli Li Huiyu Li Wei han He Wen Yinghong han Chunxia Che Yongjun feng State Key Laboratory of Chemical Resource Engineering Beijing Engineering Center for Hierarchical CatalystsCollege of ChemistryBeijing University of Chemical TechnologyBeijing100029China Lanzhou Petrochemical Research Center Petrochemical Research InstitutePetroChinaLanzhou730060China

The pore structure of spherical alumina supports is closely related to the dispersion of catalytically active components and the diffusion of reactants.Maintaining excellent pore structure under strict reaction conditions is of utmost importance.In this work,sphericalγ-Al_(2)O_(3)support with a bimodal pore structure,composed of macropores and mesopores,was successfully synthesized using dodecane as the pore-forming agent through the oil–ammonia column-shaping method.The morphology and internal pore structure of the alumina were found to be influenced by the amount of surfactant added and ultrasound treatment conditions.Notably,when concentration of surfactant was 4‰and ultrasound voltage of 20 V was applied,the resultingγ-Al_(2)O_(3)-4‰-20 displayed a highly concentrated distribution of macropores with an average pore size of 100 nm,resulting in an impressive porosity of 69.21%.In contrast,the untreated sample ofγ-Al_(2)O_(3)-0-0 only exhibited a mesoporous distribution with a porosity of 54.03%.Moreover,after being subjected to a hydrothermal treatment in a high temperature(600°C)and high humidity(water vapor)environment for 120 h,theγ-Al_(2)O_(3)-4‰-20 sample maintained a high BET specific surface area of 170.9 m^(2)g^(−1)and mercury intrusion porosimetry specific surface area of 263.3 m^(2)g^(−1).

关键词： Spherical alumina supports Pore-forming agent Oil-ammonia column shaping method Hydrothermal treatment Hydrothermal stability