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Experimental Study on the Wavelengths of Two-Dimensional and Three-Dimensional Freak Waves

China Ocean Engineering 2023年第1期37卷 154-164页

作者： CUI Cheng pan Wen-bo National Engineering Research Center for Port Hydraulic Construction Technology M.O.T.Tianjin Research Institute of Water Transport EngineeringTianjin 300456China

Freak waves are commonly characterized by strong-nonlinearity, and the wave steepness, which is calculated from the wavelength, is a measure of the degree of the wave nonlinearity. Moreover, the wavelength can describe the locally spatial characteristics of freak waves. Generally, the wavelengths of freak waves are estimated from the dispersion relations of Stokes waves. This paper concerns whether this approach enables a consistent estimate of the wavelength of freak waves. The two-(unidirectional, long-crested) and three-dimensional(multidirectional, shortcrested) freak waves are simulated experimentally through the dispersive and directional focusing of component waves, and the wavelengths obtained from the surface elevations measured by the wave gauge array are compared with the results from the linear, 3rd-order and 5th-order Stokes wave theories. The comparison results suggest that the 3rd-order theory estimates the wavelengths of freak waves with higher accuracy than the linear and 5th-order theories. Furthermore, the results allow insights into the dominant factors. It is particularly noteworthy that the accuracy is likely to depend on the wave period, and that the wavelengths of longer period freak waves are overestimated but the wavelengths are underestimated for shorter period ones. In order to decrease the deviation, a modified formulation is presented to predict the wavelengths of two-and three-dimensional freak waves more accurately than the 3rd-order dispersion relation, by regression analysis. The normalized differences between the predicted and experimental results are over 50% smaller for the modified model suggested in this study compared with the 3rd-order dispersion relation.

关键词： freak wave rogue wave wavelength three-dimension directional spread multidirectional wave

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喷雾助剂对乙基多杀菌素药液在杧果叶片润湿铺展行为的影响

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热带作物学报 2025年第1期46卷 180-188页

作者：潘波王冰洁杜长远林勇姜蕾中国热带农业科学院环境与植物保护研究所海南海口571101 农业农村部热带作物有害生物综合治理重点实验室海南海口571101 华中农业大学植物科学技术学院湖北武汉430070

乙基多杀菌素是防治杧果蓟马的常用药剂之一,农药喷雾助剂的添加可以提高农药的药效。合理选择和使用助剂产品,对提高农药利用率、减少农药使用量至关重要。本研究通过测定添加5种不同类型、不同浓度的农药助剂产品后乙基多杀菌素药液... 详细信息

乙基多杀菌素是防治杧果蓟马的常用药剂之一,农药喷雾助剂的添加可以提高农药的药效。合理选择和使用助剂产品,对提高农药利用率、减少农药使用量至关重要。本研究通过测定添加5种不同类型、不同浓度的农药助剂产品后乙基多杀菌素药液的静态、动态表面张力,以及药液在杧果叶片正面、背面的接触角、铺展面积和蒸发时间,探究不同类型农药助剂产品在杧果叶片表面的润湿铺展行为。结果表明:添加不同助剂产品均能有效降低乙基多杀菌素药液的静态、动态表面张力,同时降低药液在叶片表面的接触角,提高药液在杧果叶片表面的铺展面积。除高分子类助剂(诺普信天盾)在叶片背面表现出抗蒸发性外,其他助剂产品均缩短了蒸发时间。不同类型的助剂产品在杧果叶片上的润湿性表现并不一致,有机硅类助剂(极润)润湿性最好,其余依次为硅酸金属复合盐类助剂(迈道)、改性植物油(迈飞)、橙皮精油(丹罗丰)、高分子类助剂(诺普信天盾)。通过比较不同处理组药液在杧果叶片正面、背面的润湿铺展行为,得出叶片背面比正面更难以被农药药液润湿。药液的理化性质和叶片的表面结构是影响喷雾液滴在叶片上润湿行为的重要因素。杧果蓟马常常在叶片背面活动取食,因此在防治杧果蓟马时,应根据助剂的类型、蓟马的为害特点选择合适的浓度,才能取得较好的防治效果。研究结果揭示了不同类型助剂在杧果叶片上的润湿铺展行为,为合理选择使用农药喷雾助剂产品提供数据支撑。

关键词：喷雾助剂表面张力接触角润湿面积干燥时间杧果

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Development of a novel hand-eye calibration for intuitive control of minimally invasive surgical robot

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Frontiers of Mechanical Engineering 2022年第3期17卷 91-108页

作者： Yanwen SUN bo pan Yili FU State Key Laboratory of Robotics and Systems Harbin Institute of TechnologyHarbin150001China

Robotic-assisted surgical system has introduced a powerful platform through dexterous instrument and hand-eye coordination intuitive *** knowledge of laparoscopic vision is a crucial piece of information for robot-assisted minimally invasive surgery focusing on improved surgical *** the transformation with respect to the laparoscope and robot slave arm frames using hand-eye calibration is essential,which is a key component for developing intuitive control *** proposed a novel two-step modified dual quaternion for hand-eye calibration in this *** dual quaternion was exploited to solve the hand-eye calibration simultaneously and powered by an iteratively separate *** obtained hand-eye calibration result was applied to the intuitive control by using the hand-eye coordination *** simulations and experimental studies were conducted to evaluate the proposed method on our surgical robot *** extensively compared the proposed method with state-of-the-art *** demonstrate this method can improve the calibration *** effectiveness of the intuitive control algorithm was quantitatively evaluated,and an improved hand-eye calibration method was *** relationship between laparoscope and robot kinematics can be established for intuitive control.

关键词： minimally invasive surgery hand-eye calibration intuitive control surgical robot dual quaternion

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Ultrasound-guided prostate percutaneous intervention robot system and calibration by informative particle swarm optimization

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Frontiers of Mechanical Engineering 2022年第1期17卷 18-33页

作者： Jiawen YAN bo pan Yili FU State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China

Applying a robot system in ultrasound-guided percutaneous intervention is an effective approach for prostate cancer diagnosis and *** limited space for robot manipulation restricts structure volume and *** this paper,an 8-degree-of-freedom robot system is proposed for ultrasound probe manipulation,needle positioning,and needle insertion.A novel parallel structure is employed in the robot system for space saving,structural rigidity,and collision *** particle swarm optimization method based on informative value is proposed for kinematic parameter identification to calibrate the parallel structure *** method identifies parameters in the modified kinematic model stepwise according to parameter *** experiments prove that the robot system can realize motions needed in *** applying the calibration method,a reasonable,reliable forward kinematic model is built,and the average errors can be limited to 0.963 and 1.846 mm for insertion point and target point,respectively.

关键词： ultrasound image guidance prostate percutaneous intervention parallel robot kinematics identification particle swarm optimization informative value

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Recent progress of residual stress measurement methods: A review

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Chinese Journal of Aeronautics 2021年第2期34卷 54-78页

作者： Jiang GUO Haiyang FU bo pan Renke KANG Key Laboratory for Precision and Non-traditional Machining of Ministry of Education Dalian University of TechnologyDalian 116024China

Residual stress is one of the main factors affecting the mechanical properties of materials, such as their strength, plasticity and surface integrity. For instance, tensile stress conditions can adversely affect material performance or component life, while compressive stress conditions can improve material fatigue strength. During the processing of integrated aviation structures, machining deformation caused by residual stress has become one of the most prominent manufacturing problems. Therefore, it is very important to measure and evaluate the stress for real *** paper reviews the research of residual stress measurement methods over the past five years by classifying them according to the measurement methods appearing in each stage. The existing problems and difficulties of each measurement technology are summarized, and future trends are forecasted. This paper provides a reference for further in-depth study of residual stress measurement technologies.

关键词： Destructive testing Future trends Measurement Nondestructive testing Residual stress

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Noteworthy phenomena in pediatric inherited cardiomyopathy

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World Journal of Pediatrics 2024年第6期20卷 635-637页

作者： Jin-Hang Jiang Jie Tian bo pan Department of Pediatric Cardiology National Clinical Key Cardiovascular SpecialtyNational Clinical Research Center for Child Health and DisordersMinistry of Education Key Laboratory of Child Development and DisordersChildren's Hospital of Chongqing Medical University136 Zhongshan Er RoadYuzhong DistirctChongqing 400014China Key Laboratory of Children's Important Organ Development and Diseases Chongqing Municipal Health CommissionChongqingChina

Pediatric cardiomyopathy has an early onset and poor ***,it was referred to as idiopathic cardiomyopathy due to unknown ***,recent advances in molecular genetics and molecular biology have demonstrated that most pediatric cardiomyopathy cases are related to genetic factors,mainly involving single gene and single nucleotide mutations[1,2].Although the pathogenicity of some gene mutations in patients has not been fully elucidated,genetic factors are still considered the main cause of pediatric cardiomyopathy.

关键词： cardiomyopathy pediatric etiology

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General closed-form inverse kinematics for arbitrary three-joint subproblems based on the product of exponential model

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Frontiers of Mechanical Engineering 2022年第2期17卷 85-101页

作者： Tao SONG bo pan Guojun NIU Jiawen YAN Yili FU State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China School of Mechanical Engineering and Automation Zhejiang Sci-Tech UniversityHangzhou 310018China

The inverse kinematics problems of robots are usually decomposed into several Paden–Kahan subproblems based on the product of exponential model. However, the simple combination of subproblems cannot solve all the inverse kinematics problems, and there is no common approach to solve arbitrary three-joint subproblems in an arbitrary postural relationship. The novel algebraic geometric (NAG) methods that obtain the general closed-form inverse kinematics for all types of three-joint subproblems are presented in this paper. The geometric and algebraic constraints are used as the conditions precedent to solve the inverse kinematics of three-joint subproblems. The NAG methods can be applied in the inverse kinematics of three-joint subproblems in an arbitrary postural relationship. The inverse kinematics simulations of all three-joint subproblems are implemented, and simulation results indicating that the inverse solutions are consistent with the given joint angles validate the general closed-form inverse kinematics. Huaque III minimally invasive surgical robot is used as the experimental platform for the simulation, and a master–slave tracking experiment is conducted to verify the NAG methods. The simulation result shows the inverse solutions and six sets given joint angles are consistent. Additionally, the mean and maximum of the master–slave tracking experiment for the closed-form solution are 0.1486 and 0.4777 mm, respectively, while the mean and maximum of the master–slave tracking experiment for the compensation method are 0.3188 and 0.6394 mm, respectively. The experiments results demonstrate that the closed-form solution is superior to the compensation method. The results verify the proposed general closed-form inverse kinematics based on the NAG methods.

关键词： inverse kinematics Paden-Kahan subproblems three-joint subproblems product of exponential closed-form solution

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Understanding the hydroxyl adsorption behavior at Pt electrode surface in high-temperature alkaline solutions

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Chinese Journal of Chemical Engineering 2023年第2期54卷 173-179页

作者： bo pan Biao Liu Shaona Wang Yeqing Lv Hao Du Yi Zhang National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology Key Laboratory of Green Process and EngineeringInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100190China

Since the application in fuel cell,the electrochemical adsorption of hydroxyl has received considerable attention in recent *** most research mainly focus on the room temperature,in this paper,the electrochemical adsorption of hydroxyl in alkaline solution at high temperature was *** unusual oxidation peak was observed at-0.27 V,suggesting new behavior of hydroxyl adsorption *** is known two kinds of cation hydrated clusters exist in alkaline solution,(H_(2)O)_(x-1)M^(+)-H_(2)O-O_(ad)H and(H_(2)O)_xM^(+)-O_(ad)*** K^(+)and Cs^(+),the cluster shows unstable structure due to the weak interaction between hydrated cation and OH^(-)especially at high ***,For Li^(+),Na^(+)the cluster structure would be stable,as the interaction force between the hydrated cation and OH^(-)is so *** was revealed that the unusual oxidation peak has some relationship with the(H_(2)O)_(x-1)M^(+)-H_(2)O-O_(ad)H cluster(K^(+)and Cs^(+))absorbed at Pt electrode *** the temperature was raised,(H_(2)O)_(x-1)M^(+)-H_(2)O-and-O_(ad)H was disconnected,then the O_(ad)H absorbed at Pt surface got *** on the SEM observation,it was showed the unusual electrochemical oxidation reaction would generate platinum oxides,blocking the reactive sites at Pt electrode surface,thus reducing the electrochemical reactivity of Pt ***,parameters of alkaline concentration and temperature were systematically studied,it was found that increase temperature or alkaline concentration was in favor of the unusual oxidation *** study provides more understanding of hydroxyl adsorption behavior at Pt electrode surface for the high temperature water solution environment.

关键词： Alkaline solution Hydroxyl adsorption Cationic species High temperature Cationic hydrated clusters

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Environmental behavior of engineered biochars and their aging processes in soil

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Biochar 2019年第4期1卷 339-351页

作者： Wenyan Duan Patryk Oleszczuk bo pan Baoshan Xing Faculty of Environmental Science and Engineering Kunming University of Science and TechnologyKunming 650500People’s Republic of China Yunnan Key Lab of Soil Carbon Sequestration and Pollution Control Kunming University of Science and TechnologyKunming 650500People’s Republic of China Department of Environmental Chemistry University of Maria Skłodowska-Curiepl.M.Curie-Sklodowskiej 320-031 LublinPoland Stockbridge School of Agriculture University of MassachusettsAmherstMA 01003USA

In recent years,due to the broad application of biochars,the preparation,environmental behavior and aging processes of biochars have attracted wide attention globally,especially the modification of ***,most of the studies only consider the improvement of biochar properties right after the modification,but neglect a complete evaluation of the long-term stability and eco-toxicity of these newly developed materials after entering the *** the development and utilization of biochars,engineered biochars(EngBCs)will soon enter the market,but its environmental risk still remains *** literature does not provide adequate information on how aging of EngBCs will affect their properties,and indirectly impact the properties of soils(cycle of elements and organic matter).Therefore,this review paper summarizes the aging process and environmental risk of biochars,aiming at better understanding the interactions between EngBCs and soil components or *** importantly,this review is to point out the contradictory speculations of environmental behavior of EngBCs studied at the present *** to the modification,the EngBCs stability may be significantly ***,the formation of functional group on EngBCs will enhance their interaction with soil minerals to form biochars-mineral complex,and thus EngBCs could be *** impacts of EngBCs after entering the environment are also ***,understanding EngBCs environmental behavior is critical,which is helpful to reduce the potential risk and to produce EngBCs following the rule of sustainable development and safety to the environment.

关键词： Biochar modification Stability Toxicity Soil components Organic contaminants

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Numerical Simulation and Entropy Production Analysis of Centrifugal Pump with Various Viscosity

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Computer Modeling in Engineering & Sciences 2024年第11期141卷 1111-1136页

作者： Zhenjiang Zhao Lei Jiang Ling Bai bo pan Ling Zhou National Research Center of Pumps Jiangsu UniversityZhenjiang212013China School of Energy and Power Engineering Jiangsu UniversityZhenjiang212013China Shandong Xinchuan Mining Equipment Co. Ltd.Jining272300China

The fluid’s viscosity significantly affects the performance of a centrifugal *** entropy production method and leakage are employed to analyze the performance changes under various viscosities by numerical simulation and validated by *** results showed that increasing viscosity reduces both the pump head and *** addition,the optimal operating point shifts to the *** is influenced by vortex distribution in the front chamber and boundary layer thickness in wear-ring clearance,leading to an initial increase and subsequent decrease in leakage with increasing *** total entropy production Spro,Total inside the pump rises with increasing *** different mechanisms dominate under varying conditions:Turbulent dissipation dominates at low *** high-viscosity conditions,energy loss is primarily caused by direct dissipation Spro,D and wall entropy production Spro,*** study provides a deeper and more objective understanding of the energy characteristics of centrifugal pumps handling fluids of various viscosity,potentially aiding in optimizing pump design and improving energy conversion efficiency.

关键词： Centrifugal pump numerical simulation viscosity leakage entropy production

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