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Visual navigation in orchard based on multiple images at different shooting angles
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作者 MA Zenghong YUE Jiawen +3 位作者 YIN Cheng ZHAO Runmao CHANDA Mulongoti DU Xiaoqiang 《智能化农业装备学报(中英文)》 2024年第4期51-65,共15页
The orchards usually have rough terrain,dense tree canopy and weeds.It is hard to use GNSS for autonomous navigation in orchard due to signal occlusion,multipath effect,and radio frequency interference.To achieve auto... The orchards usually have rough terrain,dense tree canopy and weeds.It is hard to use GNSS for autonomous navigation in orchard due to signal occlusion,multipath effect,and radio frequency interference.To achieve autonomous navigation in orchard,a visual navigation method based on multiple images at different shooting angles is proposed in this paper.A dynamic image capturing device is designed for camera installation and multiple images can be shot at different angles.Firstly,the obtained orchard images are classified into sky and soil detection stage.Each image is transformed to HSV space and initially segmented into sky,canopy and soil regions by median filtering and morphological processing.Secondly,the sky and soil regions are extracted by the maximum connected region algorithm,and the region edges are detected and filtered by the Canny operator.Thirdly,the navigation line in the current frame is extracted by fitting the region coordinate points.Then the dynamic weighted filtering algorithm is used to extract the navigation line for the soil and sky detection stage,respectively,and the navigation line for the sky detection stage is mirrored to the soil region.Finally,the Kalman filter algorithm is used to fuse and extract the final navigation path.The test results on 200 images show that the accuracy of visual navigation path fitting is 95.5%,and single frame image processing costs 60 ms,which meets the real-time and robustness requirements of navigation.The visual navigation experiments in Camellia oleifera orchard show that when the driving speed is 0.6 m/s,the maximum tracking offset of visual navigation in weed-free and weedy environments is 0.14 m and 0.24 m,respectively,and the RMSE is 30 mm and 55 mm,respectively. 展开更多
关键词 ORCHARD visual navigation multiple shooting angles region segmentation Kalman filter
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Optimal index shooting policy for layered missile defense system 被引量:1
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作者 LI Longyue FAN Chengli +2 位作者 XING Qinghua XU Hailong ZHAO Huizhen 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2020年第1期118-129,共12页
In order to cope with the increasing threat of the ballistic missile(BM)in a shorter reaction time,the shooting policy of the layered defense system needs to be optimized.The main decisionmaking problem of shooting op... In order to cope with the increasing threat of the ballistic missile(BM)in a shorter reaction time,the shooting policy of the layered defense system needs to be optimized.The main decisionmaking problem of shooting optimization is how to choose the next BM which needs to be shot according to the previous engagements and results,thus maximizing the expected return of BMs killed or minimizing the cost of BMs penetration.Motivated by this,this study aims to determine an optimal shooting policy for a two-layer missile defense(TLMD)system.This paper considers a scenario in which the TLMD system wishes to shoot at a collection of BMs one at a time,and to maximize the return obtained from BMs killed before the system demise.To provide a policy analysis tool,this paper develops a general model for shooting decision-making,the shooting engagements can be described as a discounted reward Markov decision process.The index shooting policy is a strategy that can effectively balance the shooting returns and the risk that the defense mission fails,and the goal is to maximize the return obtained from BMs killed before the system demise.The numerical results show that the index policy is better than a range of competitors,especially the mean returns and the mean killing BM number. 展开更多
关键词 Gittins index shooting policy layered missile defense multi-armed bandits problem Markov decision process
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Reliability and Validity of the New Shooting Accuracy Measurement (SAM) System Software
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《Journal of Sports Science》 2017年第3期172-177,共6页
The aim of this study was to investigate the reliability and validity of the New Shooting Accuracy Measurement Software (SAMS). Thirty two male collegian soccer players performed three inner side kicking to the tran... The aim of this study was to investigate the reliability and validity of the New Shooting Accuracy Measurement Software (SAMS). Thirty two male collegian soccer players performed three inner side kicking to the transparent goal construction. A High speed camera was placed at the back of the construction to determine where the ball contacted. Recorded video results were assessed with the SAMS and Kinovea software. To investigate test-retest reliability, three kicking results were examined twice by SAMS. Moreover kicking accuracy results obtained with SAMS were compared with results provided by Kinovea in order to investigate validity. Test-retest reproducibility of the new software was excellent, with Concordance Correlation Coefficient for distance to target (0.99, 0.99 and 0.99 respectively) and for angular degree of the ball (0.97, 0.99 and 0.99 respectively), low Coefficients of Variation (between 2.10 to 6.33 for distance to target and 2.40 to 2.69 for angular degree) and random error (between _.+ 0.55 to __+ 3.44 for distance to target and ___ 0.63 to ___ 2.75 for angular degree). Constant error (between 0.44 to 1.28 for distance to target and -1.16 to __. -2.51 for angular degree) and proportional error (between 0.97 to 0.98 for distance to target and 1.00 to 1.01 for angular degree) were very low for validity. In conclusion, the SAMS represents a valid and reliable instrument to measure accuracy of shooting to target. 展开更多
关键词 shooting kicking ACCURACY MEASUREMENT distance.
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A two-parameter multiple shooting method and its application to the natural vibrations of non-prismatic multi-segment beams
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作者 R.HOŁUBOWSKI K.JARCZEWSKA 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2023年第12期2243-2252,共10页
This paper presents an enhanced version of the standard shooting method that enables problems with two unknown parameters to be solved.A novel approach is applied to the analysis of the natural vibrations of Euler-Ber... This paper presents an enhanced version of the standard shooting method that enables problems with two unknown parameters to be solved.A novel approach is applied to the analysis of the natural vibrations of Euler-Bernoulli beams.The proposed algorithm,named as two-parameter multiple shooting method,is a new powerful numerical tool for calculating the natural frequencies and modes of multi-segment prismatic and non-prismatic beams with different boundary conditions.The impact of the axial force and additional point masses is also taken into account.Due to the fact that the method is based directly on the fourth-order ordinary differential equation,the structures do not have to be divided into many small elements to obtain an accurate enough solution,even though the geometry is very complex.To verify the proposed method,three different examples are considered,i.e.,a three-segment non-prismatic beam,a prismatic column subject to non-uniformly distributed compressive loads,and a two-segment beam with an additional point mass.Numerical analyses are carried out with the software MATHEMATICA.The results are compared with the solutions computed by the commercial finite element program SOFiSTiK.Good agreement is achieved,which confirms the correctness and high effectiveness of the formulated algorithm. 展开更多
关键词 two-parameter multiple shooting method two-point boundary value problem natural vibration non-prismatic beam multi-segment beam
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Efficient Decomposition Shooting Method for Solving Third-Order Boundary Value Problems
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作者 Nawal Al-Zaid Kholoud Alzahrani +1 位作者 Huda Bakodah Mariam Al-Mazmumy 《International Journal of Modern Nonlinear Theory and Application》 2023年第3期81-98,共18页
The present paper proposes a mathematical method to numerically treat a class of third-order linear Boundary Value Problems (BVPs). This method is based on the combination of the Adomian Decomposition Method (ADM) and... The present paper proposes a mathematical method to numerically treat a class of third-order linear Boundary Value Problems (BVPs). This method is based on the combination of the Adomian Decomposition Method (ADM) and, the modified shooting method. A complete derivation of the proposed method has been provided, in addition to its numerical implementation and, validation via the utilization of the Runge-Kutta method and, other existing methods. The method has been applied to diverse test problems and turned out to perform remarkably. Lastly, the simulated numerical results have been graphically illustrated and, also supported by some absolute error comparison tables. 展开更多
关键词 Linear Third Order BVPs shooting Method Adomian Decomposition Method Two-Point Boundary Value Problem
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Establishment of Green Cotton Regeneration System 被引量:3
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作者 侍福梅 王超 《Agricultural Science & Technology》 CAS 2010年第1期8-11,共4页
[Objective]The aimed to optimize transformation system for Agrobacterium-mediated green cotton shoot tip and provide reference for genetic engineering-assisted breeding of color cotton. [Method]With shoot tip of natur... [Objective]The aimed to optimize transformation system for Agrobacterium-mediated green cotton shoot tip and provide reference for genetic engineering-assisted breeding of color cotton. [Method]With shoot tip of natural green cotton as receptor and by using Agrobacterium-mediated transformation method,the optimum conditions of regeneration system were obtained. [Result]Combining with vacuum infiltration,3-old-day shoot tips were infected for 10 minutes in Abarobacterium suspension with OD600 value about 0.5 followed by co-culture for 24 h on the medium containing MS+l mg/L KT,pH value of 5.8. The regeneration culture was conducted in MS medium containing l mg/L KT and increasingly 30,50 and 70 mg/L Kan. The highest transformation frequency was 34.6%,and the positive resistant plantlets of green cotton 9804 were obtained. [Conclusion]Green cotton is more beneficial than white cotton to conduct genetic transformation. 展开更多
关键词 Green cotton Shoot tip Genetic transformation AGROBACTERIUM
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Rice gene OsUGT75A regulates seedling emergence under deep-sowing conditions
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作者 Jia Zhao Siyu Liu +5 位作者 Xiaoqian Zhao Zhibo Huang Shan Sun Zixuan Zeng Yongqi He Zhoufei Wang 《The Crop Journal》 SCIE CSCD 2024年第1期133-141,共9页
Poor seedling emergence is a challenge for direct seeding of rice under deep-sowing field conditions.Here we reveal that UDP-glucosyltransferase OsUGT75A promotes rice seedling emergence under deepsowing conditions by... Poor seedling emergence is a challenge for direct seeding of rice under deep-sowing field conditions.Here we reveal that UDP-glucosyltransferase OsUGT75A promotes rice seedling emergence under deepsowing conditions by increasing shoot length.Expression of OsUGT75A was higher in the middle regions of the shoot and in shoots under deep-sowing conditions.Levels of free abscisic acid(ABA)and jasmonates(JA)were higher in shoots of OsUGT75A mutants than in those of wild-type plants,and OsUGT75A mutants were more sensitive to ABA and JA treatments.Reduced shoot length was attributed to higher ABA INSENSITIVE 3(OsABI3)expression and lower JASMONATE-ZIM domain protein(OsJAZ)expression in shoots.Shoot extension by OsUGT75A is achieved mainly by promotion of cell elongation.An elite haplotype of OsUGT75A associated with increased shoot length was identified among indica rice accessions.OsUGT75A acts to increase seedling emergence under deep-sowing conditions. 展开更多
关键词 Abscisic acid Deep-sowing Jasmonic acid RICE Shoot length
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Electromagnetic scattering and imaging simulation of extremely large-scale sea-ship scene based on GPU parallel technology
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作者 Cheng-Wei Zhang Zhi-Qin Zhao +2 位作者 Wei Yang Li-Lai Zhou Hai-Yu Zhu 《Journal of Electronic Science and Technology》 EI CAS CSCD 2024年第2期16-23,共8页
Aiming to solve the bottleneck problem of electromagnetic scattering simulation in the scenes of extremely large-scale seas and ships,a high-frequency method by using graphics processing unit(GPU)parallel acceleration... Aiming to solve the bottleneck problem of electromagnetic scattering simulation in the scenes of extremely large-scale seas and ships,a high-frequency method by using graphics processing unit(GPU)parallel acceleration technique is proposed.For the implementation of different electromagnetic methods of physical optics(PO),shooting and bouncing ray(SBR),and physical theory of diffraction(PTD),a parallel computing scheme based on the CPU-GPU parallel computing scheme is realized to balance computing tasks.Finally,a multi-GPU framework is further proposed to solve the computational difficulty caused by the massive number of ray tubes in the ray tracing process.By using the established simulation platform,signals of ships at different seas are simulated and their images are achieved as well.It is shown that the higher sea states degrade the averaged peak signal-to-noise ratio(PSNR)of radar image. 展开更多
关键词 Multi graphics processing unit Radar imaging Sea-ship shooting and bouncing rays
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Lactobacillus from fermented bamboo shoots prevents inflammation in DSS-induced colitis mice via modulating gut microbiome and serum metabolites
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作者 Xiangru Liu Xiaoling Lu +6 位作者 Hao Nie Jing Yan Zhiwen Ma Hailin Li Shixin Tang Qi Yin Jingfu Qiu 《Food Science and Human Wellness》 SCIE CAS CSCD 2024年第5期2833-2846,共14页
Fermented bamboo shoots(FBS)is a region-specific food widely consumed in Southwestern China,with Lactobacillus as the predominant fermenting bacteria.However,the probiotic potential of Lactobacillus derived from FBS r... Fermented bamboo shoots(FBS)is a region-specific food widely consumed in Southwestern China,with Lactobacillus as the predominant fermenting bacteria.However,the probiotic potential of Lactobacillus derived from FBS reminds largely unexplored,especially for diseases with a low prevalence in areas consuming FBS,namely,inflammatory bowel disease.In this study,Lactiplantibacillus pentosus YQ001 and Lentilactobacillus senioris YQ005 were screening by in vitro probiotic tests to further investigate the probioticlike bioactivity in dextran sulfate sodium(DSS)-induced ulcerative colitis(UC)mouse.They exhibited more positive probiotic effects than Lactobacillus rhamnosus GG in preventing intestinal inflammatory response.The results revealed that both strains improved the abundance of deficient intestinal microbiota in UC mice,including Muribaculaceae and Akkermansia.In the serum metabolome,they modulated the DSS-disturbed levels of metabolites,with significant increment of cinnamic acid.Meanwhile,they reduced the expression levels of interleukin-1β(IL-1β),interleukin-6(IL-6)inflammatory factors and increased zonula occludens-1(ZO-1),Occludin,and cathelicidin-related antimicrobial peptide(CRAMP)in the colon.Consequently,these results demonstrated that Lactobacillus spp.isolates derived from FBS showed promising probiotic activity based on the gut microbiome homeostasis modulation,anti-inflammation and intestinal barrier protection in UC mice. 展开更多
关键词 Fermented bamboo shoots LACTOBACILLUS Probiotic activity Gut microbiome modulation Ulcerative colitis
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Summer Warming Limited Bud Output Drives a Decline in Daughter Shoot Biomass through Reduced Photosynthetis of Parent Shoots in Leymus chinensis Seedlings
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作者 Song Gao Ruocheng Xu +4 位作者 Lin Li Jiao Wang Nian Liu Johannes M.H.Knops Junfeng Wang 《Phyton-International Journal of Experimental Botany》 SCIE 2024年第7期1667-1675,共9页
Understanding how summer warming influences the parent and daughter shoot production in a perennial clonal grass is vital for comprehending the response of grassland productivity to global warming.Here,we conducted a s... Understanding how summer warming influences the parent and daughter shoot production in a perennial clonal grass is vital for comprehending the response of grassland productivity to global warming.Here,we conducted a simulated experiment using potted Leymus chinensis,to study the relationship between the photosynthetic activ-ity of parent shoots and the production of daughter shoots under a whole(90 days)summer warming scenario(+3°C).The results showed that the biomass of parents and buds decreased by 25.52%and 33.45%,respectively,under warming conditions.The reduction in parent shoot biomass due to warming directly resulted from decreased leaf area(18.03%),chlorophyll a(18.27%),chlorophyll b(29.21%)content,as well as a reduction in net photosynthetic rate(7.32%)and the maximum quantum efficiency of photosystem II(PSII)photochemistry(4.29%).The decline in daughter shoot biomass was linked to a decrease in daughter shoot number(33.33%)by warming.However,the number of belowground buds increased by 46.43%.The results indicated that long-term summer warming reduces biomass accumulation in parent shoot by increasing both limitation of stoma and non-stoma.Consequently,the parent shoot allocates relatively more biomass to the belowground organs to maintain the survival and growth of buds.Overall,buds,as a potential aboveground population,could remedy for the cur-rent loss of parent shoot density by increasing the number of future daughter shoots if summer warming subsides. 展开更多
关键词 Warming parent shoot bud bank photosynthesis chlorophyllfluorescence Leymus chinensis
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The IDD Transcription Factors:Their Functions in Plant Development and Environmental Response
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作者 Jing Liu Defeng Shu +5 位作者 Zilong Tan Mei Ma Huanhuan Yang Ning Guo Shipeng Li Dayong Cui 《Phyton-International Journal of Experimental Botany》 SCIE 2024年第1期63-79,共17页
INDETERMINATE-DOMAIN proteins(IDDs)are a plant-specific transcription factor family characterized by a conserved ID domain with four zinc finger motifs.Previous studies have demonstrated that IDDs coordinate a diversi... INDETERMINATE-DOMAIN proteins(IDDs)are a plant-specific transcription factor family characterized by a conserved ID domain with four zinc finger motifs.Previous studies have demonstrated that IDDs coordinate a diversity of physiological processes and functions in plant growth and development,including floral transition,plant architecture,seed and root development,and hormone signaling.In this review,we especially summarized the latest knowledge on the functions and working models of IDD members in Arabidopsis,rice,and maize,particularly focusing on their role in the regulatory network of biotic and abiotic environmental responses,such as gravity,temperature,water,and pathogens.Understanding these mechanisms underlying the function of IDD proteins in these processes is important for improving crop yields by manipulating their activity.Overall,the review offers valuable insights into the functions and mechanisms of IDD proteins in plants,providing a foundation for further research and potential applications in agriculture. 展开更多
关键词 INDETERMINATE DOMAIN flowering time root development shoot gravitropism plant immunity hormonal signaling environmental responses
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Multi-Scale Mixed Attention Tea Shoot Instance Segmentation Model
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作者 Dongmei Chen Peipei Cao +5 位作者 Lijie Yan Huidong Chen Jia Lin Xin Li Lin Yuan Kaihua Wu 《Phyton-International Journal of Experimental Botany》 SCIE 2024年第2期261-275,共15页
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... 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. 展开更多
关键词 Tea shoots attention mechanism multi-scale feature extraction instance segmentation deep learning
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规范场论中自对偶磁单极子解的存在唯一性
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作者 陈筱 《Chinese Quarterly Journal of Mathematics》 2024年第1期86-96,共11页
Magnetic monopoles stand for the static solution arising from a(1 + 3)–dimensional theory describing the interaction between a real scalar triplet and non–Abelian gauge field. In this paper, we obtain a two–point b... Magnetic monopoles stand for the static solution arising from a(1 + 3)–dimensional theory describing the interaction between a real scalar triplet and non–Abelian gauge field. In this paper, we obtain a two–point boundary value problem of a first–order ordinary differential equations from the self–dual monopole model. Then we establish the existence and uniqueness theorem for the problem by using a dynamical shooting method, we also obtain sharp asymptotic estimates for the solutions at infinity. 展开更多
关键词 Self-dual monopole Dynamical shooting method Existence and uniqueness
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Application of Large-Scale Systems Theory in Fire Control Systems
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作者 史天运 何广存 《Journal of Beijing Institute of Technology》 EI CAS 1995年第1期21+17-21,共6页
According the to the model of single tank fire control system, this paper makes use of decomposition-coordination theory of large-scale systems to discuss the shooting problem of multiple tank the control systems, and... According the to the model of single tank fire control system, this paper makes use of decomposition-coordination theory of large-scale systems to discuss the shooting problem of multiple tank the control systems, and alalyzes specifically the three-tank the control systems and models.the process was imitated in computer, and the optimal shooting element of 3TS system was got. In addition, probability of hitting the target was calculated. 展开更多
关键词 large-scale systems fire control systems coordination/shooting error probability of hitting the target
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Influence of Temperature-Dependent Thermophysical Properties of TiO2-SiO2-ZnO-Fe2O3/PAO Tetra-Hybrid Nanofluid along a Vertical Porous Surface with Suction
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作者 Philip Iyiola Farayola Lateefat Olanike Aselebe +2 位作者 Kafilat Adebimpe Salaudeen Saheed Dolapo Ogundiran Tajudeen Motunrayo Asiru 《Open Journal of Fluid Dynamics》 2024年第3期123-146,共24页
The significance of the thermophysical properties of Tetra hybrid nanofluid in enhancing heat transmission in various applications like heat exchangers, automobiles, and solar storage cannot be overstated. These featu... The significance of the thermophysical properties of Tetra hybrid nanofluid in enhancing heat transmission in various applications like heat exchangers, automobiles, and solar storage cannot be overstated. These features can be tampered with when nanoparticles are been introduced into the base fluid to produce an improved heat carrier fluid for the system. This study investigates the impact of temperature-dependent properties on the movement of TiO2-SiO2-ZnO-Fe2O3/PAO Tetra hybrid nanofluid along a vertical porous surface with suction. The system of governing Partial Differential Equations (PDEs) was formulated and transformed into the system of coupled nonlinear third-order Ordinary Differential Equations (ODEs) by similarity techniques. The resulting ODEs were solved numerically using the shooting method and fourth order Runge-Kutta method with the aid of Maple 18.0 software. Using numerical and statistical methods, the study analyzes velocity, temperature profiles, skin friction coefficient, and Nusselt number. It was found that as the variable thermal conductivity parameter upsurges both the skin friction coefficient and Nusselt number intensify at the rate of 0.011697519 and 8.043581616 respectively. This study underscores the vital role of Tetra hybrid nanofluid’s thermophysical properties in improving heat transmission for diverse appli cations. By manipulating nanoparticles within the base fluid, the heat carrier fluid’s efficiency can be enhanced, critical for industries like automotive and enewable energy. These insights inform the design of more efficient heat exchange systems, advancing sustainability and performance in real-world scenarios. 展开更多
关键词 Tetra Hybrid Nanofluid shooting Technique Numerical Method Skin Friction Nusselt Number Thermophysical Properties
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Hybrid Nanofluid Flow over a Stretching Curved Surface with Induced Magnetic Field and Homogeneous-Heterogeneous Reactions
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作者 Ming Shen Yunhua Zheng +2 位作者 Yihong Liu Hui Chen Mengchen Zhang 《Journal of Applied Mathematics and Physics》 2024年第10期3638-3654,共17页
This study explores the 2D stretching flow of a hybrid nanofluid over a curved surface influenced by a magnetic field and reactions. A steady laminar flow model is created with curvilinear coordinates, considering the... This study explores the 2D stretching flow of a hybrid nanofluid over a curved surface influenced by a magnetic field and reactions. A steady laminar flow model is created with curvilinear coordinates, considering thermal radiation, suction, and magnetic boundary conditions. The nanofluid is made of water with copper and MWCNTs as nanoparticles. The equations are transformed into nonlinear ODEs and solved numerically. The model’s accuracy is confirmed by comparing it with published data. Results show that fluid velocity increases, temperature decreases, and concentration increases with the curvature radius parameter. The hybrid nanofluid is more sensitive to magnetic field changes in velocity, while the nanofluid is more sensitive to magnetic boundary coefficient changes. These insights can optimize heat and mass transfer in industrial processes like chemical reactors and wastewater treatment. 展开更多
关键词 Hybrid Nanofluids Stretching Curved Surface Induced Magnetic Field Improved shooting Method
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Study of Potential Edaphic Chemical Factors in the Prevalence of Swollen Shoot Disease of Cocoa in the Marahoué Region (Côte d’Ivoire)
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作者 Ferdinand Gohi Bi Zro Martinez Arnauth Guei +3 位作者 Zoumana Konate Tchimou Elvis Paterne Dogniméton Soro Sidiky Bakayoko 《Open Journal of Soil Science》 2024年第10期660-673,共14页
This study looks at the prevalence of swollen shoot disease in cocoa plantations in the Marahoué region of Côte d’Ivoire, a key cocoa-producing area. Cocoa accounts for around a third of the country’s expo... This study looks at the prevalence of swollen shoot disease in cocoa plantations in the Marahoué region of Côte d’Ivoire, a key cocoa-producing area. Cocoa accounts for around a third of the country’s export earnings, but production is under threat from the swollen shoot virus, which is causing major yield reductions. The aim of the study is to establish a link between the chemical properties of the soil and the presence of the disease, in particular the levels of carbon, nitrogen, phosphorus, calcium and acidity (pH) in the soil. Specifically, soils from healthy plots were compared with soils from infested plots in six plantations in the Bouaflé and Kononfla sub-prefectures. The results show that soils from infested plots have lower phosphorus levels and near-neutral acidity in the 20 - 40 cm soil layer, while soils from healthy plots are slightly acidic and contain more calcium and phosphorus. These chemical differences seem to influence the prevalence of the virus. Low phosphorus levels appear to be a key factor in the vulnerability of cocoa trees to the disease. The study therefore suggests that any strategy to combat swollen shoot should include better soil management, incorporating factors such as soil depth and the availability of essential nutrients. In addition, an assessment of the micro-organisms present in the soil could provide further information on the interactions between the soil and the disease. 展开更多
关键词 Soil Chemical Properties Cocoa Swollen Shoot Marahoué Region
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Influence of core box vents distribution on flow dynamics of core shooting process based on experiment and numerical simulation 被引量:4
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作者 Chang-jiang Ni Gao-chun Lu +4 位作者 Qing-dong Zhang Tao Jing Jun-jiao Wu Lin-long Yang Qin-fang Wu 《China Foundry》 SCIE 2016年第1期22-29,共8页
Core shooting process plays a decisive role in the quality of sand cores, and core box vents distribution is one of the most important factor determining the effectiveness of core shooting process. In this paper, the ... Core shooting process plays a decisive role in the quality of sand cores, and core box vents distribution is one of the most important factor determining the effectiveness of core shooting process. In this paper, the influence of core box vents distribution on the flow dynamics of core shooting process was investigated based on in situ experimental observations with transparent core box, high-speed camera and pressure measuring system. Attention was focused on the variation of both the flow behavior of sand and pressure curves due to different vents distribution. Taking both kinetic and frictional stress into account, a kinetic-frictional constitutive model was established to describe the internal momentum transfer in the solid phase. Two-fluid model(TFM) simulation was then performed and good agreement was achieved between the experimental and simulated results on both the flow behavior of sand and the pressure curves. It was found that vents distribution has direct effect on the pressure difference of different locations in the core box, which determines the buoyancy force exerting on the sand particles and significantly influences the filling process of core sand. 展开更多
关键词 vents distribution flow dynamics pressure variation core shooting process kinetic-frictional model two-fluid model
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A CASE STUDY ON LONG HOLE RAISING BY SHOOTING TO RELIEF HOLES 被引量:2
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作者 Ding Dexin Central South Institute of Technology, Hengyang 421001 《中国有色金属学会会刊:英文版》 CSCD 1997年第3期160-163,共4页
ACASESTUDYONLONGHOLERAISINGBYSHOOTINGTORELIEFHOLES①DingDexinCentralSouthInstituteofTechnology,Hengyang42100... ACASESTUDYONLONGHOLERAISINGBYSHOOTINGTORELIEFHOLES①DingDexinCentralSouthInstituteofTechnology,Hengyang421001ABSTRACTAcasestu... 展开更多
关键词 LONG HOLE RAISING shooting RELIEF HOLES
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An Improved System for Shoot Regeneration from Stem Explants of Lombardy Poplar (Populus nigra L. var. italica Koehne) 被引量:4
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作者 Kamal Kanti Biswas Takeshi Mohri +2 位作者 Satoshi Kogawara Yoshihiro Hase Yutaka Oono 《American Journal of Plant Sciences》 2012年第9期1181-1186,共6页
We developed a system for the regeneration of Lombardy poplar (Populus nigra L. var. italica) shoots from internodal stem explants. Using this system, shoots regenerated from 87% of the stem explants placed on Murashi... We developed a system for the regeneration of Lombardy poplar (Populus nigra L. var. italica) shoots from internodal stem explants. Using this system, shoots regenerated from 87% of the stem explants placed on Murashige and Skoog (MS) medium supplemented with 0.1 mg/L indole-3-acetic acid and 0.5 mg/L benzylaminopurine without undergoing callus formation. About 80% of the in vitro regenerated shoots developed roots on MS medium supplemented with 0.5 mg/L indole-3-butyric acid and 0.02 mg/L 1-naphthylacetic acid. Well-rooted seven-to eight-week-old regenerated plants could be transferred to soil for further growth and the survival rate of such plants after three weeks was 88%. The protocol presented here is simple and economical because it does not rely on pre-incubation in callus induction medium or repeated subculture in shoot induction medium containing trans-zeatin, an expensive substance. The in vitro regeneration system presented here could be used for evaluation of radiation sensitivity for Lombardy poplar tissues. 展开更多
关键词 Lombardy POPLAR SHOOT Regeneration STEM EXPLANTS AUXIN and Benzylaminopurine Radiation Sensitivity
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