Limonene’s Bacteriostatic Activity against Ralstonia solanacearum by Compromised Membrane Integrity: A Transcriptomic and Metabolomic Analysis

Ralstonia solanacearum, the causative agent of bacterial wilt, is a soil-borne pathogen that poses a widespread threat to plants in the Solanaceae family. To elucidate the mechanism by which limonene exerts its effects on R. solanacearum, we first assessed the impact of limonene on the physiological indicators of the pathogen and subsequently analyzed its transcriptome and metabolome. Our findings indicate that limonene has a potent inhibitory effect on R. solanacearum, and it also suppresses the formation of the bacterial community biofilm. Limonene primarily regulates the terpene biosynthesis pathway in R. solanacearum, thereby potentially affecting signal transduction in the pathogen and disrupting its normal growth and development. These results significantly enhance our understanding of limonene’s response to the induction of bacterial wilt and provide a reference for further prevention and control of R. solanacearum.

Superhydrophobic Surface-Assisted Preparation of Microspheres and Supraparticles and Their Applications

Superhydrophobic surface(SHS) has been well developed, as SHS renders the property of minimizing the water/solid contact interface. Water droplets deposited onto SHS with contact angles exceeding 150°, allow them to retain spherical shapes, and the low adhesion of SHS facilitates easy droplet collection when tilting the substrate. These characteristics make SHS suitable for a wide range of applications. One particularly promising application is the fabrication of microsphere and supraparticle materials. SHS offers a distinct advantage as a universal platform capable of providing customized services for a variety of microspheres and supraparticles. In this review, an overview of the strategies for fabricating microspheres and supraparticles with the aid of SHS, including cross-linking process, polymer melting,and droplet template evaporation methods, is first presented. Then, the applications of microspheres and supraparticles formed onto SHS are discussed in detail, for example, fabricating photonic devices with controllable structures and tunable structural colors, acting as catalysts with emerging or synergetic properties, being integrated into the biomedical field to construct the devices with different medicinal purposes, being utilized for inducing protein crystallization and detecting trace amounts of analytes. Finally,the perspective on future developments involved with this research field is given, along with some obstacles and opportunities.

High-rate electrochemical H_(2)O_(2) production over multimetallic atom catalysts under acidic–neutral conditions

Hydrogen peroxide(H_(2)O_(2))production by the electrochemical 2-electron oxygen reduction reaction(2e−ORR)is a promising alternative to the energy-intensive anthraquinone process,and single-atom electrocatalysts show the unique capability of high selectivity toward 2e−ORR against the 4e−one.The extremely low surface density of the single-atom sites and the inflexibility in manipulating their geometric/electronic configurations,however,compromise the H_(2)O_(2) yield and impede further performance enhancement.Herein,we construct a family of multiatom catalysts(MACs),on which two or three single atoms are closely coordinated to form high-density active sites that are versatile in their atomic configurations for optimal adsorption of essential*OOH species.Among them,the Cox–Ni MAC presents excellent electrocatalytic performance for 2e−ORR,in terms of its exceptionally high H_(2)O_(2) yield in acidic electrolytes(28.96 mol L^(−1) gcat.^(−1) h^(−1))and high selectivity under acidic to neutral conditions in a wide potential region(>80%,0–0.7 V).Operando X-ray absorption and density functional theory analyses jointly unveil its unique trimetallic Co2NiN8 configuration,which efficiently induces an appropriate Ni–d orbital filling and modulates the*OOH adsorption,together boosting the electrocatalytic 2e−ORR capability.This work thus provides a new MAC strategy for tuning the geometric/electronic structure of active sites for 2e−ORR and other potential electrochemical processes.

多组学数据驱动的机器学习模型在乳腺癌生存及治疗响应预测中的应用

乳腺癌的高度异质性导致其治疗及预后评估较为复杂。治疗方案的选择受到肿瘤亚型、病变分级、基因型等多种因素的影响,因此需要制定个体化治疗策略。患者的预后效果因病情不同而产生显著差异。作为人工智能的一个重要分支,机器学习能高效处理海量数据,并实现决策过程的自动化。机器学习方法的引入将为乳腺癌治疗的选择和预后评估提供新的解决方案。在癌症治疗领域,传统方法预测生存与治疗效果往往依赖于单一或少量的生物标志物,难以全面捕捉复杂的生物学过程。机器学习通过分析患者的多组学数据以及它们在疾病发生发展过程中复杂的变化趋势,预测患者的生存和治疗响应效果,从而选择适合的治疗措施,实施早期干预,改善患者的治疗效果。本文首先介绍了常用的机器学习方法,在此基础上分别从评估生存情况和预测治疗效果这两方面展开,详细分析了机器学习在乳腺癌患者生存预测及预后领域中的应用,以期为乳腺癌患者提供精准医疗治疗策略,提高治疗效果和生存质量。

Photocatalytic seawater splitting by 2D heterostructure of ZnIn_(2)S_(4)/WO_(3) decorated with plasmonic Au for hydrogen evolution under visible light

Photocatalytic H_(2) evolution from seawater splitting presents a promising approach to tackle the fossil energy crisis and mitigate carbon emission due to the abundant source of seawater and sunlight on the earth.However,the development of efficient photocatalysts for seawater splitting remains a formidable challenge.Herein,a 2D/2D ZnIn_(2)S_(4)/WO_(3)(ZIS/WO_(3))heterojunction nanostructure is fabricated to efficiently separate the photoinduced carriers by steering electron transfer from the conduction band minimum of WO_(3) to the valence band maximum of ZIS via constructing internal electric field.Subsequently,plasmonic Au nanoparticles(NPs)as a novel photosensitizer and a reduction cocatalyst are anchored on ZIS/WO_(3) surface to further enhance the optical absorption of ZIS/WO_(3) heterojunction and accelerate the catalytic conversion.The obtained Au/ZIS/WO_(3) photocatalyst exhibits an outstanding H_(2) evolution rate of 2610.6 or 3566.3μmol g^(-1)h~(-1)from seawater splitting under visible or full-spectrum light irradiation,respectively.These rates represent an impressive increase of approximately 7.3-and 6,6-fold compared to those of ZIS under the illumination of the same light source.The unique 2D/2D structure,internal electric field,and plasmonic metal modification together boost the photocatalytic H_(2) evolution rate of Au/ZIS/WO_(3),making it even comparable to H_(2) evolution from pure water splitting.The present work sheds light on the development of efficient photocatalysts for seawater splitting.

Generative Multi-Modal Mutual Enhancement Video Semantic Communications

Recently,there have been significant advancements in the study of semantic communication in single-modal scenarios.However,the ability to process information in multi-modal environments remains limited.Inspired by the research and applications of natural language processing across different modalities,our goal is to accurately extract frame-level semantic information from videos and ultimately transmit high-quality videos.Specifically,we propose a deep learning-basedMulti-ModalMutual Enhancement Video Semantic Communication system,called M3E-VSC.Built upon a VectorQuantized Generative AdversarialNetwork(VQGAN),our systemaims to leverage mutual enhancement among different modalities by using text as the main carrier of transmission.With it,the semantic information can be extracted fromkey-frame images and audio of the video and performdifferential value to ensure that the extracted text conveys accurate semantic information with fewer bits,thus improving the capacity of the system.Furthermore,a multi-frame semantic detection module is designed to facilitate semantic transitions during video generation.Simulation results demonstrate that our proposed model maintains high robustness in complex noise environments,particularly in low signal-to-noise ratio conditions,significantly improving the accuracy and speed of semantic transmission in video communication by approximately 50 percent.

A Model for Helmet-Wearing Detection of Non-Motor Drivers Based on YOLOv5s

Detecting non-motor drivers’helmets has significant implications for traffic control.Currently,most helmet detection methods are susceptible to the complex background and need more accuracy and better robustness of small object detection,which are unsuitable for practical application scenar-ios.Therefore,this paper proposes a new helmet-wearing detection algorithm based on the You Only Look Once version 5(YOLOv5).First,the Dilated convolution In Coordinate Attention(DICA)layer is added to the backbone network.DICA combines the coordinated attention mechanism with atrous convolution to replace the original convolution layer,which can increase the perceptual field of the network to get more contextual information.Also,it can reduce the network’s learning of unnecessary features in the background and get attention to small objects.Second,the Rebuild Bidirectional Feature Pyramid Network(Re-BiFPN)is used as a feature extraction network.Re-BiFPN uses cross-scale feature fusion to combine the semantic information features at the high level with the spatial information features at the bottom level,which facilitates the model to learn object features at different scales.Verified on the proposed“Helmet Wearing dataset for Non-motor Drivers(HWND),”the results show that the proposed model is superior to the current detection algorithms,with the mean average precision(mAP)of 94.3%under complex background.

Construction of Industrialization Development Model for"1+4+X"Community-Based Elderly Care in Gannan Old Revolutionary Base Area in the Context of Population Aging

In the context of controlling population development in a planned way,China entered an aging society in the early 21 st century.In this context,how to meet the needs of the elderly care and form an effective elderly care model has become a key problem to be solved urgently by local government departments.With the continuous advancement of the elderly care policy,the community-based elderly care has gradually become the mainstream and is in the stage of vigorous promotion.Taking the Gannan old revolutionary base area in Jiangxi Province as an example,this study puts forward"1+4+X"community-based elderly care model based on the policy system of community-based elderly care,the physical and mental health of the elderly,the material space and the construction of evaluation system,and explores how to promote the application of this community model efficiently in the form of industrialization,so as to drive the economic growth of the Gannan old revolutionary base area,promote the employment development and improve the community-based elderly care service.

Estimation of inbreeding and identification of regions under heavy selection based on runs of homozygosity in a Large White pig population

Background: Runs of homozygosity(ROHs) are homozygous segments of the genome where the two haplotypes inherited from the parents are identical. The current availability of genotypes for a very large number of single nucleotide polymorphisms(SNPs) is leading to more accurate characterization of ROHs in the whole genome. Here,we investigated the occurrence and distribution of ROHs in 3,692 Large White pigs and compared estimates of inbreeding coefficients calculated based on ROHs(FROH), homozygosity(FHOM), genomic relationship matrix(FGRM)and pedigree(FPED). Furthermore, we identified genomic regions with high ROH frequencies and annotated their candidate genes.Results: In total, 176,182 ROHs were identified from 3,569 animals, and all individuals displayed at least one ROH longer than 1 Mb. The ROHs identified were unevenly distributed on the autosomes. The highest and lowest coverages of Sus scrofa chromosomes(SSC) by ROH were on SSC14 and SSC13, respectively. The highest pairwise correlation among the different inbreeding coefficient estimates was 0.95 between FROH_totaland FHOM, while the lowest was-0.083 between FGRMand FPED. The correlations between FPEDand FROHusing four classes of ROH lengths ranged from 0.18 to 0.37 and increased with increasing ROH length, except for ROH > 10 Mb. Twelve ROH islands were located on four chromosomes(SSC1, 4, 6 and 14). These ROH islands harboured genes associated with reproduction, muscular development, fat deposition and adaptation, such as SIRT1, MYPN, SETDB1 and PSMD4.Conclusion: FROHcan be used to accurately assess individual inbreeding levels compared to other inbreeding coefficient estimators. In the absence of pedigree records, FROHcan provide an alternative to inbreeding estimates.Our findings can be used not only to effectively increase the response to selection by appropriately managing the rate of inbreeding and minimizing the negative effects of inbreeding depression but also to help detect genomic regions with an effect on traits under selection.

关于蔬果农药残留现象的实践调研

厦门大学化学化工学院“一点一滴”实践队结合所学专业知识,针对果蔬农药残留现象进行了实践调研。通过对不同背景市民进行的调查访问,了解到他们对农药残留的认识及日常采用的去除办法存在一定疑惑。在大量文献调研的基础上,总结目前农药残留的检测手段,从中筛选并优化适合本次实践活动的测定方法。对部分去除农药残留的方法进行实验检验,根据测定结果给出相应的建议。本次实践活动将所学专业知识运用于实际,培养和提高了学生的实践能力和综合素质。

Error suppression techniques for energy-efficient high-resolution SAR ADCs

The successive approximation register(SAR)is one of the most energy-efficient analog-to-digital converter(ADC)architecture for medium-resolution applications.However,its high energy efficiency quickly diminishes when the target resolution increases.This is because a SAR ADC suffers from several major error source,including the sampling kT/C noise,the comparator noise,and the DAC mismatch.These errors are increasing hard to address in high-resolution SAR ADCs.This paper reviews recent advances on error suppression techniques for SAR ADCs,including the sampling kT/C noise reduction,the noise-shaping(NS)SAR,and the mismatch error shaping(MES).These techniques aim to boost the resolution of SAR ADCs while maintaining their superior energy efficiency.

Highly active and sintering-resistant heteroepitaxy of Au nanoparticles on ZnO nanowires for CO oxidation

Gold was supported on commercial ZnO powders(P) and homemade ZnO nanowires(NWs) by a modified deposition–precipitation method. X-ray diffraction and transmission electron microscopy investigation indicated that the size of the Au nanoparticles(NPs) depended strongly on the calcination temperature.The Au NPs were highly dispersed(< 5 nm) on both supports with calcination temperatures < 400 °C.However, after calcination at 600 °C the Au NPs aggregated much more severely on ZnO P than on ZnO NWs. Gold NPs epitaxially grew into the {10–10} facets of the ZnO NWs after calcination at temperatures > 400 °C. Such unique anchoring mechanism accounts for the much better experimentally observed sintering resistance. X-ray photoelectron spectra showed that Au existed as both metallic Au0 and Auδ+species in all the synthesized catalysts with or without calcination treatment; the ratios of Auδ+/Au0,however, varied, depending on the treatment conditions. Catalytic tests showed that the activity for CO oxidation strongly depended on the size of the Au NPs. After calcination at 600 °C, the specific rate for CO oxidation at room temperature decreased about 30 times on Au/ZnO P but only about 4 times on Au/ZnO NW. Stability tests demonstrated that the Au/ZnO NW catalysts had better stability for CO oxidation.

Estimates of genomic inbreeding and identification of candidate regions that differ between Chinese indigenous sheep breeds

Background:A run of homozygosity(ROH)is a consecutive tract of homozygous genotypes in an individual that indicates it has inherited the same ancestral haplotype from both parents.Genomic inbreeding can be quantified based on ROH.Genomic regions enriched with ROH may be indicative of selection sweeps and are known as ROH islands.We carried out ROH analyses in five Chinese indigenous sheep breeds;Altay sheep(n=50 individuals),Large-tailed Han sheep(n=50),Hulun Buir sheep(n=150),Short-tailed grassland sheep(n=150),and Tibetan sheep(n=50),using genotypes from an Ovine Infinium HD SNP BeadChip.Results:A total of 18,288 ROH were identified.The average number of ROH per individual across the five sheep breeds ranged from 39(Hulun Buir sheep)to 78(Large-tailed Han sheep)and the average length of ROH ranged from 0.929 Mb(Hulun Buir sheep)to 2.544 Mb(Large-tailed Han sheep).The effective population size(Ne)of Altay sheep,Large-tailed Han sheep,Hulun Buir sheep,Short-tailed grassland sheep and Tibetan sheep were estimated to be 81,78,253,238 and 70 five generations ago.The highest ROH-based inbreeding estimate(FROH)was 0.0808 in Large-tailed Han sheep,whereas the lowest F_(ROH)was 0.0148 in Hulun Buir sheep.Furthermore,the highest proportion of long ROH fragments(>5 Mb)was observed in the Large-tailed Han sheep breed which indicated recent inbreeding.In total,49 ROH islands(the top 0.1% of the SNPs most commonly observed in ROH)were identified in the five sheep breeds.Three ROH islands were common to all the five sheep breeds,and were located on OAR2:12.2-12.3 Mb,OAR12:78.4-79.1 Mb and OAR13:53.0-53.6 Mb.Three breed-specific ROH islands were observed in Altay sheep(OAR15:3.4-3.8 Mb),Large-tailed Han sheep(ORA17:53.5-53.8 Mb)and Tibetan sheep(ORA5:19.8-20.2 Mb).Collectively,the ROH islands harbored 78 unique genes,including 19 genes that have been documented as having associations with tail types,adaptation,growth,body size,reproduction or immune response.Conclusion:Different ROH patterns were observed in five Chinese indigenous sheep breeds,which reflected their different population histories.Large-tailed Han sheep had the highest genomic inbreeding coefficients and the highest proportion of long ROH fragments indicating recent inbreeding.Candidate genes in ROH islands could be used to illustrate the genetic characteristics of these five sheep breeds.Our findings contribute to the understanding of genetic diversity and population demography,and help design and implement breeding and conservation strategies for Chinese sheep.

COMTIS:Customizable touchless interaction system for large screen visualization

Background Large screen visualization sys tems have been widely utilized in many industries.Such systems can help illustrate the working states of different production systems.However,efficient interaction with such systems is still a focus of related research.Methods In this paper,we propose a touchless interaction system based on RGB-D camera using a novel bone-length constraining method.The proposed method optimizes the joint data collected from RGB-D cameras with more accurate and more stable results on very noisy data.The user can customize the system by modifying the finite-state machine in the system and reuse the gestures in multiple scenarios,reducing the number of gestures that need to be designed and memorized.Results/Conclusions The authors tested the system in two cases.In the first case,we illustrated a process in which we improved the gesture designs on our system and tested the system through user study.In the second case,we utilized the system in the mining industry and conducted a user study,where users say that they think the system is easy to use.

A rapid and sensitive liquid chromatography–tandem mass spectrometric method for the determination of hederasaponin B in rat plasma: Application to a pharmacokinetic study

A rapid, simple and sensitive ultra-high performance liquid chromatography–tandem mass spectrometric(UPLC–MS/MS) method was developed and validated for the determination of hederasaponin B, an active triterpenoid saponin widely existed in Hedera helix L. Plasma samples were processed by protein precipitation with acetonitrile and separated on a Thermo Hypersil GOLD C18(2.1 mm × 50 mm,1.9 μm) at flow rate of 0.3 ml/min, with a gradient elution consisting of acetonitrile and water containing 0.1%(v/v) formic acid at 30 ℃ and detected by electrospray ionization mass spectrometry in the positive multiple reaction monitoring(MRM) mode. The linearity was found to be within the concentration range of 0.5–5000 ng/ml with a lower limit of quantification of 0.5 ng/ml. The absolute oral bioavailability of hederasaponin B was 0.24 ± 0.49%. This indicated that the concentration-time course of the hederasaponin B existed a double-peak phenomenon. This method was further applied to the determination of hederasaponin B in rat plasma and showed good practicability, for the first time, after intragastric(25 mg/kg) and intravenous(2 mg/kg) administration in rats.

纳米银对椰油酰基谷氨酸三乙醇胺盐表面活性的影响

以N-椰油酰基谷氨酸为原料,原位化学还原法绿色制备50 mg/kg纳米银和椰油酰基谷氨酸三乙醇(TEA)胺盐,获得纳米银椰油酰基谷氨酸TEA胺盐复合体系。采用电导法、表面张力法、接触角法及罗氏泡沫仪研究纳米银对复合体系的cmc、泡沫性能、pH、Krafft点以及润湿性能的影响,结果表明:纳米银可增强体系的起泡性能和稳泡性能;随着纳米银用量的增加,体系的cmc值先降后升,起泡性能呈现先增强后下降趋势,对pH、Krafft点、润湿性能的影响均不明显,本实验中5%的50 mg/kg纳米银对椰油酰基谷氨酸TEA胺盐的表面活性有优良的协同效应。采用UV-Vis、FT-IR和Zeta电位探究纳米银的作用机制,发现体系中纳米银没有离解,随着其用量的提高,纳米银倾向以静电作用的方式吸附于N-H键附近,产生配位效应,物理吸附大于化学吸附;随着纳米银用量的增加,复配体系的Zeta电位绝对值下降,但Zeta电位绝对值大于50 mV,表明纳米银椰油酰基谷氨酸TEA胺盐复配体系有着较好的稳定性。

几何偏差对可控扩散叶型性能影响规律及机理

为了研究几何偏差对叶型性能的影响规律和机理,采用Hicks-Henne函数模化叶型轮廓度偏差、轮廓度变化率偏差,并叠加在可控扩散叶型(CDA)上,对偏差叶型进行了S1流面数值计算。计算结果表明,轮廓度变化率较小时,叶型性能随正负轮廓度偏差幅值的变化趋势是对称的,但轮廓度变化率较大时,正负轮廓度偏差均会导致叶型性能下降,正偏差的影响超过负偏差。几何偏差造成的附面层局部分离甚至提前转捩是叶型性能降低的主要原因。基于上述研究建立了CDA叶型几何偏差敏感区,敏感区域包括距离前缘5%弦长以内的叶型区域及附面层转捩点之前的吸力面区域。偏差敏感区有利于改进加工公差准则,降低压气机气动性能风险。

Effects of physical crust on soil detachment by overland flow in the Loess Plateau region of China

Physical soil crust(PSC),a key component of surface soil structure,exists extensively in loess areas.PSC is considered to have a significant effect on soil detachment processes.However,the long-term effects and the corresponding mechanisms of PSC on soil detachment by overland flow are still not well understood,especially in natural environments.To investigate temporal variation in soil erosion resistance and the underlying factors during PSC formation,an 8×8-m soil plot was exposed to natural conditions in the Loess Plateau over a 524-day period spanning two rainy seasons and a winter between them.A flume test was conducted to determine soil detachment capacity(Dc)under six designed flow shear stress levels(5.66-22.11 Pa)using crusted(SC)and non-crusted(NSC)soil samples at different PSC development stages.Subsequently,two soil erosion resistance parameters,rill erodibility(K_(r))and critical shear stress(τ_(c)),were calculated.Over time,in the SC and NSC treatments,K_(r)decreased from 0.516 to 0.120 s m^(-1)and 0.521 to 0.223 s m^(-1),respectively,whileτ_(c)increased from 0.49 to 4.42 Pa and 0.26-2.46 Pa,respectively.Variation in soil erosion resistance was rapid in the first one to two months,and then slowed down,with slight fluctuations afterwards.In the SC treatment,K_(r)was 42%lower andτ_(c)was 67%greater than those in the NSC treatment.Soil properties changed greatly for both treatments.SCT increased from 0 to 7.09 mm in the SC treatment.Coh increased from 2.91 to 9.04 kPa and 3.01-4.78 kPa in SC and NSC treatments,respectively.Both soil erosion resistance parameters could be well predicted by SCT and Coh in the SC treatment(R^(2)≥0.82),while their best predictor was Coh in the NSC treatment(R^(2)≥0.90).The results demonstrate that PSC formation enhances soil erosion resistance in the soil detachment process in the loess region under natural conditions.Our study revealed the important role and complexity of PSC in the process of soil erosion,and provided theoretical and data support for accurate understanding and prediction of soil erosion.

Regulate electric double layer for one-step synthesize and modulate the morphology of(oxy)hydroxides

FeOOH have received considerable attention due to their natural abundance and cost-effectiveness.Despite the significant progress achieved,the one-step synthesis of integrated FeOOH is still a major challenge.Meanwhile,the current research on FeOOH catalyst still suffers from the unclear mechanism of controlling morphology.Here,density functional theory(DFT)calculations and X-ray photoelectron spectroscopy(XPS)demonstrated the strong electron-capturing and hydrogen absorption ability of Co in FeOOH,which further promotes the formation and stabilization of FeOOH.We used a one-step electrodeposition method to synthesize Co introduced FeOOH integrated electrocatalyst and propose to introduce ions with different valence states to regulate the morphology of FeOOH by precise modulation of electric double layer(EDL)composition and thickness.The prepared Co-FeOOH-K^(+)has a larger electrochemically active surface area(ECSA)(325 cm^(2))and turnover frequency(TOF)value(0.75 s^(-1)).In the electrochemical experiments of an alkaline anion exchange membrane electrolyzer,Co-FeOOH-K^(+)shows better oxygen evolution performance than commercial RuO_(2) under industrial production conditions and has good industrial application prospects.

Method for the navigation line recognition of the ridge without crops via machine vision

Some agriculture machinery like the transplanter,needs to operate by following the crop-free ridges.In order to improve working efficiency and quality,some autonomous navigation systems were developed and applied to ridge-following machinery.At present,agricultural navigation systems are mainly the satellite navigation system and the machine vision system.The satellite navigation system is difficult to apply to the machinery that needs to work by following the ridge because it cannot distinguish the shape of the navigated ridge and guide the machinery working along the ridge.In this study,697 cloudy ridge images and 235 sunny ridge images were taken in the field,and these images were used as the dataset.Moreover,a machine vision navigation method based on the color of ridges was proposed.Firstly,the regions of interest(ROI)in the ridge image were extracted according to the reaction time and the forward speed of the machine.Then,a gray reconstruction method was used to enlarge the color difference between the ridge and the furrow.The optimal threshold for the gray image segmenting was calculated real-timely by using the threshold segmentation method.Then,based on the contour detection method,the ridge contour which was not surrounded by holes was extracted.Finally,the approximate quadrilateral method was proposed to recognize the ridge center line as the navigation line.The method proposed in this study was verified by four types of ridges with different colors and textures.The experimental results showed that the recognition success rates of the light ridge,the dark ridge,the film-covered ridge,and the sunny ridge were 100%,97.5%,100%,and 98.7%,respectively.The recognition success rate of the proposed method was at least 8%higher than that of the existing ridge-furrow recognition methods.The results indicate that this method can effectively realize navigation line recognition.This method can provide technical support for the autonomous navigation of agricultural machinery,such as transplanters,seeders,etc.,operating on the ridge without crops.