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Multi-Scale Mixed Attention Tea Shoot Instance Segmentation Model

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Phyton-International Journal of Experimental Botany 2024年第2期93卷 261-275页

作者： Dongmei Chen Peipei Cao Lijie Yan Huidong Chen Jia lin Xin Li lin yuan Kaihua Wu School of Automation Hangzhou Dianzi UniversityHangzhou310018China Tea Research Institute Chinese Academy of Agriculture SciencesHangzhou310018China School of Information Engineering Zhejiang University of Water Resources and Electric PowerHangzhou310018China

Tea leaf picking is a crucial stage in tea production that directly influences the quality and value of the tea.Traditional tea-picking machines may compromise the quality of the tea leaves.High-quality teas are often handpicked and need more delicate operations in intelligent picking machines.Compared with traditional image processing techniques,deep learning models have stronger feature extraction capabilities,and better generalization and are more suitable for practical tea shoot harvesting.However,current research mostly focuses on shoot detection and cannot directly accomplish end-to-end shoot segmentation tasks.We propose a tea shoot instance segmentation model based on multi-scale mixed attention(Mask2FusionNet)using a dataset from the tea garden in Hangzhou.We further analyzed the characteristics of the tea shoot dataset,where the proportion of small to medium-sized targets is 89.9%.Our algorithm is compared with several mainstream object segmentation algorithms,and the results demonstrate that our model achieves an accuracy of 82%in recognizing the tea shoots,showing a better performance compared to other models.Through ablation experiments,we found that ResNet50,PointRend strategy,and the Feature Pyramid Network(FPN)architecture can improve performance by 1.6%,1.4%,and 2.4%,respectively.These experiments demonstrated that our proposed multi-scale and point selection strategy optimizes the feature extraction capability for overlapping small targets.The results indicate that the proposed Mask2FusionNet model can perform the shoot segmentation in unstructured environments,realizing the individual distinction of tea shoots,and complete extraction of the shoot edge contours with a segmentation accuracy of 82.0%.The research results can provide algorithmic support for the segmentation and intelligent harvesting of premium tea shoots at different scales.

关键词： Tea shoots attention mechanism multi-scale feature extraction instance segmentation deep learning

Development of Spectral Features for Monitoring Rice Bacterial Leaf Blight Disease Using Broad-Band Remote Sensing Systems

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Phyton-International Journal of Experimental Botany 2024年第4期93卷 745-762页

作者： Jingcheng Zhang Xingjian Zhou Dong Shen Qimeng Yu lin yuan Yingying Dong College of Artificial Intelligence Hangzhou Dianzi UniversityHangzhou310018China School of Information Engineering Zhejiang University of Water Resources and Electric PowerHangzhou310018China Key Laboratory of Digital Earth Science Aerospace Information Research InstituteChinese Academy of SciencesBeijing100094China

As an important rice disease, rice bacterial leaf blight (RBLB, caused by the bacterium Xanthomonas oryzae pv.oryzae), has become widespread in east China in recent years. Significant losses in rice yield occurred as a result ofthe disease’s epidemic, making it imperative to monitor RBLB at a large scale. With the development of remotesensing technology, the broad-band sensors equipped with red-edge channels over multiple spatial resolutionsoffer numerous available data for large-scale monitoring of rice diseases. However, RBLB is characterized by rapiddispersal under suitable conditions, making it difficult to track the disease at a regional scale with a single sensorin practice. Therefore, it is necessary to identify or construct features that are effective across different sensors formonitoring RBLB. To achieve this goal, the spectral response of RBLB was first analyzed based on the canopyhyperspectral data. Using the relative spectral response (RSR) functions of four representative satellite or UAVsensors (i.e., Sentinel-2, GF-6, Planet, and Rededge-M) and the hyperspectral data, the corresponding broad-bandspectral data was simulated. According to a thorough band combination and sensitivity analysis, two novel spectralindices for monitoring RBLB that can be effective across multiple sensors (i.e., RBBRI and RBBDI) weredeveloped. An optimal feature set that includes the two novel indices and a classical vegetation index was formed.The capability of such a feature set in monitoring RBLB was assessed via FLDA and SVM algorithms. The resultdemonstrated that both constructed novel indices exhibited high sensitivity to the disease across multiple sensors.Meanwhile, the feature set yielded an overall accuracy above 90% for all sensors, which indicates its cross-sensorgenerality in monitoring RBLB. The outcome of this research permits disease monitoring with different remotesensing data over a large scale.

关键词： Rice bacterial leaf blight analysis of spectral response multispectral data simulation vegetation indices cross-sensor disease monitoring

Development of a droplet digital polymerase chain reaction assay for the sensitive detection of total and integrated HIV-1 DNA

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Chinese Medical Journal 2024年第6期137卷 729-736页

作者： lin yuan Zhiying Liu Xin Zhang Feili Wei Shan Guo Na Guo Lifeng Liu Zhenglai Ma Yunxia Ji Rui Wang Xiaofan Lu Zhen Li Wei Xia Hao Wu Tong Zhang Bin Su Beijing Key Laboratory for HIV/AIDS Research Clinical and Research Center for Infectious DiseasesBeijing Youan HospitalCapital Medical UniversityBeijing 100069China Beijing Institute of Hepatology Beijing Youan HospitalCapital Medical UniversityBeijing 100069China

Background:Total human immunodeficiency virus(HIV)DNA and integrated HIV DNA are widely used markers of HIV persistence.Droplet digital polymerase chain reaction(ddPCR)can be used for absolute quantification without needing a standard curve.Here,we developed duplex ddPCR assays to detect and quantify total HIV DNA and integrated HIV DNA.Methods:The limit of detection,dynamic ranges,sensitivity,and reproducibility were evaluated by plasmid constructs containing both the HIV long terminal repeat(LTR)and human CD3 gene(for total HIV DNA)and ACH-2 cells(for integrated HIV DNA).Forty-two cases on stable suppressive antiretroviral therapy(ART)were assayed in total HIV DNA and integrated HIV DNA.Correlation coefficient analysis was performed on the data related to DNA copies and cluster of differentiation 4 positive(CD4^(+))T-cell counts,CD8^(+)T-cell counts and CD4/CD8 T-cell ratio,respectively.The assay linear dynamic range and lower limit of detection(LLOD)were also assessed.Results:The assay could detect the presence of HIV-1 copies 100%at concentrations of 6.3 copies/reaction,and the estimated LLOD of the ddPCR assay was 4.4 HIV DNA copies/reaction(95%confidence intervals[CI]:3.6-6.5 copies/reaction)with linearity over a 5-log_(10)-unit range in total HIV DNA assay.For the integrated HIV DNA assay,the LLOD was 8.0 copies/reaction(95%CI:5.8-16.6 copies/reaction)with linearity over a 3-log 10-unit range.Total HIV DNA in CD4^(+)T cells was positively associated with integrated HIV DNA(r=0.76,Plinical trials.

关键词： Human immunodeficiency virus HIV Integrated HIV-1 DNA Total HIV DNA Droplet digital polymerase chain reaction HIV reservoir Antiretroviral therapy

Experimental,Numerical,and Analytical Studies on the Bending of Mechanically lined Pipe

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China Ocean Engineering 2024年第2期38卷 221-232页

作者： WEI Wen-bin yuan lin ZHOU Jia-sheng LIU Zheng State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300072China School of Civil Engineering Tianjin UniversityTianjin 300072China School of Mechanical Engineering Tianjin UniversityTianjin 300072China

Mechanically lined pipe(MLP)is often used for offshore oil and gas transport because of its low cost and corrosion resistance.During installation and operation,the pipe may undergo severe bending deformation,which causes the liner to separate from the outer pipe and buckles,affecting the stability of the whole line.In this paper,the buckling response of MLP subjected to bending is investigated to clarify its bending characteristics by employing both experiments,numerical simulation,as theoretical methods.Two types of MLPs were manufactured with GB 45 carbon steel(SLP)and Al 6061(ALP)used as the outer pipe material,respectively.The hydraulic expansion and bending experiments of small-scale MLPs are conducted.In addition to the ovalized shape of the cross-section for the SLP specimens,the copper liner was found to wrinkle on the compressive side.In contrast,the liner of ALP remains intact without developing any wrinkling and collapse mode.In addition,a dedicated numerical framework and theoretical models were also established.It was found both the manufacturing and bending responses of the MLP can be well reproduced,and the predicted maximum moment and critical curvatures are in good agreement with the experimental results.

关键词： lined pipe bending nonlinear ring theory buckling plasticity

Correlation Study on Grain Size Characteristics and Geotechnical Properties of Surface Sediments in Qingdao Offshore Area

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Journal of Ocean University of China 2024年第3期23卷 721-730页

作者： LI Anlong WANG Panpan GUO Xijun JI Xiangkun SHEN Kunming lin lin YAN Zhichao yuan lin Key Laboratory of Submarine Geosciences and Prospecting Techniques Ministry of Education and College of Marine GeosciencesOcean University of ChinaQingdao 266100China College of Marine Geoscience Ocean University of ChinaQingdao 266100China China Construction Second Engineering Bureau Co. LTDYueyang 414000China Tianjin Research Institute for Water Transport Engineering M.O.T.Tianjin 3000456China Lianyungang Xuwei Port Holding Group Co. Ltd.Lianyungang 222042China

The comprehension of sediment grain size parameters and the corresponding sedimentary environment holds paramount importance in elucidating the engineering geological attributes of the subaqueous seabed.This study delineated the sedimentary environment zoning in the northern sea area of Qingdao through cluster analysis of grain size parameters derived from 123 surface sediment samples.The study analyzed the correlation between sediment geotechnical indices and grain size parameters across diverse sedimentary environments.A correlation equation was established for samples exhibiting a strong correlation.The study found four distinct sedimentary environments in the study area:coastal,transitional,shallow sea,and residual.Within the same sedimentary environment,the average grain size and sorting coefficient exhibit significant correlations with geotechnical indices such as water content,density,shear strength,plastic limit,liquid limit,and plastic index.However,notable disparities in the correlation between grain size parameters and geotechnical indices emerge across different sedimentary environments.

关键词： grain size parameters cluster analysis sedimentary environment correlations geotechnical indexes

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Progress and Challenges of Water-soluble NIR-II Organic Fluorophores for Fluorescence Imaging In vivo

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Chemical Research in Chinese Universities 2024年第2期40卷 190-201页

作者： XIE Yuxin QIN Zuojia QIAN Ming REN Tianbing yuan lin State Key Laboratory of Chemo/Biosensing and Chemometrics College of Chemistry and Chemical EngineeringHunan UniversityChangsha410082P.R.China

The small-molecule fluorophores for the second near-infrared(NIR-II,1000–1700 nm)window have attracted increasing attention in basic scientific research and preclinical practice owing to their deep-photo penetration,minimal physiological toxicity and simplicity of chemical modification.However,most of the reported small-molecule NIR-II fluorophores suffered from poor water solubility,which can easily cause organ toxicity.In addition,the aggregation caused by their poor water solubility in the aqueous solution would also result in weak fluorescence of these NIR-II fluorophores.Thus,it is highly desirable and valuable to develop water-soluble small-molecule NIR-II fluorophores with excellent photophysical properties for high-contrast in vivo imaging.In this review,we summarize the recent research advances in water-soluble small-molecule NIR-II fluorophores and highlight the representative bioimaging applications.Moreover,the potential challenges and perspectives of water-soluble small-molecule NIR-II fluorophores are discussed as well.We anticipate this review can help researchers to grab the latest information of water-soluble small-molecule fluorophores for NIR-II imaging,sequentially boosting their further development.

关键词： Organic fluorophore Fluorescent imaging Imaging reagent Fluorescent probe The second near-infrared(NIR-II)imaging

Critical Role of Ethylene-Propylene Block Copolymer in Impact Polypropylene Copolymer

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Chinese Journal of Polymer Science 2024年第3期42卷 344-351,I0007页

作者： Yu-Hui Tang Na Zhang Wei Bao Wei Jiang yuan lin Zhao-Hui Su State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China

Ethylene-propylene block copolymer(EbP) is a vital component in impact polypropylene copolymer(IPC), yet its distribution in the multiphase composite material and how it influences the phase structure and the mechanical properties are not well understood. In this work,four IPCs were investigated by atomic force microscopy-infrared(AFM-IR) to assess the phase compositions in situ, based on which in conjunction with the chain microstructure information obtained ex situ the distributions of the copolymer components were derived for each alloy. For the IPCs whose EbP comprises long P and long E segments, the EbP fraction was found to phase separate from the rubber and the PP matrix to form the cores of the disperse particles with the E-P segmented copolymer(EsP). In contrast, in the IPC with EbP composed of long P and short E segments, the EbP fraction formed an outer shell for the rubber particles with the cores comprising the EsP alone, and this IPC, containing a lower E comonomer content than its counterpart, exhibited both better impact resistance and higher flexural modulus. These results clarify how the chain structure of EbP governs the phase morphology in IPC, which in turn impacts the properties of the composite material.

关键词： Impact polypropylene copolymers AFM-IR Ethylene-propylene block copolymers Core-shell rubber particles

Ballistic performance of spaced multi-ply soft fabrics: Experimental and numerical investigation

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Defence Technology（防务技术） 2024年第4期34卷 143-155页

作者： Zhongwei Zhang Xiaoning Yang yuan lin Ziming Xiong Yuhang Xiang Yi Zhou Mingyang Wang State Key Laboratory of Explosion&Impact and Disaster Prevention&Mitigation Army Engineering University of PLANanjing 210007China School of Mechanical Engineering Nanjing University of Science&TechnologyNanjing 210007China State Key Laboratory of New Textile Materials and Advanced Processing Technologies Wuhan Textile UniversityWuhan 430200China Postdoctoral Station of Civil Engineering Army Engineering University of PLANanjing 210007China

It has been reported that the ply gap influences the ballistic resistance of spaced multi-ply fabric systems,but its working mechanism was not well-understood. This paper reports the experimental and numerical approaches and results of an investigation on the mechanisms that enable the improved ballistic performance of spaced multi-ply systems. Penetration tests were performed over a range of impact velocities ranging from 200 m/s to 400 m/s. The results confirmed that the ply gap is beneficial to the energy absorption capability of the systems. This is because the front plies tend to absorb more energy when they are not immediately constrained by the rear plies. During a ballistic event, the gap relieves the reflection of the compressive pulse, prolonging the projectile engagement time with the front plies;on the other hand, the rear plies become increasingly less active in dissipating energy as the gap increases.When the gap is sufficiently widened to avoid any interference between the plies before the failure of the front ply, the responses of the whole system no longer vary. It was also found that the ballistic performance of the spaced systems is influenced by ply thickness, impact velocity, and the stacking order of the ply gap.

关键词： Energy absorption capability Ply gap Ballistic performance The front ply The rear ply

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Mechanism of high-energy pulsed current-assisted rolling of 08AL carbon steel ultra-thin strip

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Journal of Iron and Steel Research(International) 2024年第2期31卷 416-427页

作者： Zhong-kai Ren Ya-nan Xu Jia-zhao Chen He Li Rui-lin yuan Zhen-hua Wang Tao Wang Xiao Liu College of Mechanical and Vehicle Engineering Taiyuan University of TechnologyTaiyuan030024ShanxiChina Engineering Research Center of Advanced Metal Composites Forming Technology and Equipment(Ministry of Education) Taiyuan University of TechnologyTaiyuan030024ShanxiChina National Key Laboratory of Metal Forming Technology and Heavy Equipment China National Heavy Machinery Research Institute Co.Ltd.Xi’an710016ShaanxiChina

To improve the plastic deformation performance of a 08AL carbon steel ultra-thin strip,a pulsed electric field was integrated into the plastic processing of the ultra-thin strip,and the effects of high-energy current on its deformation ability were investigated.Current-assisted tensile tests were employed,and the results clarified that the pulsed current could reduce the activation energy of faults and promoted dislocation slip within grains and at grain boundaries,leading to a decrease in the deformation resistance of the metal and an increase in its plastic properties.Under the current density of 2.0 A/mm2,the yield strength,tensile strength,and elongation of the rolled sample reached 425 MPa,467 MPa,and 12.5%,respectively.During the rolling process,it was found that the pulsed current promoted the dynamic recrystallization of the ultra-thin strip,reduced its dislocation density and deformation resistance,and promoted the coordinated deformation of the metal.

关键词： 08AL ultra-thin strip High-energy pulsed current Mechanical property Dislocation density Dynamic recrystallization