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Formation Principle and Characteristics of Self‑Supercharging Pulsed Water Jet

Chinese Journal of Mechanical Engineering 2022年第3期35卷 250-263页

作者： zhaolong ge Yuanfei Ling Jiren Tang Yiyu Lu Yangkai Zhang Lei Wang Qi Yao State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing UniversityChongqing 400030China National&Local Joint Engineering Laboratory of Gas Drainage in Complex Coal Seam Chongqing UniversityChongqing 400030China College of Source and Safety Chongqing UniversityChongqing 400030China

High-pressure pulsed water jet technology has considerable development potential in the field of rock fragmentation.To overcome the shortcomings of existing pulsed jets,a self-supercharging pulsed water jet(SSPWJ)generation method is proposed,which is based on the theory of the pulsed water jet and the principle of hydraulic boosting.The proposed method changes the flow direction of the fluid medium through the valve core to make the piston reciprocate in the cylinder and relies on the effective area difference between the front and rear chambers in the stroke stage of the piston to realize the organic combination of“pulse”and“supercharging”of the jet,thus forming an SSPWJ.On the basis of the formation principle of the SSPWJ,a SSPWJ testing platform was constructed,and tests were performed on the jet pressure acquisition,morphology capture,and granite erosion.Both the jet pressure and the jet morphology exhibited periodic changes,and a higher pulse pressure was obtained at lower inlet pressure.The error of the pressure ratio calculated according to the experimental results wasge of the piston,the pulse pressure and pulse frequency increase,and the pulse duration decreases.As the inlet flow rate increases in the backward-stroke stage of the piston,the pulse frequency increases,and the pulse pressure and pulse duration remain unchanged.Under the combined action of the waterhammer pressure,high-speed lateral flow,and high-frequency dynamic load of the SSPWJ,local flaky exfoliation was observed when the granite surface was eroded.The results of this study lay the foundation for enriching the theory of pulsed jet generation and expanding its application range.

关键词： Pulsed water jet Self-supercharging Pulse parameters Jet morphology Granite breaking

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Carbonic anhydrase-like enzymes in the formation of Lycopodium alkaloid

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Chinese Journal of Natural Medicines 2024年第3期22卷 193-194页

作者： DONG Huiwen ge Huiming State key Laboratory of Pharmaceutical Biotechnology Institute of Functional BiomoleculesSchool of Life SciencesNanjing UniversityNanjing 210023China

Plant alkaloids,renowned for their structural diversity and bioactivity,are prominent in both modern and traditional medicine[1].Unraveling the intricacies of plant alkaloid biosynthesis could pave the way for the discovery of new natural products and pathways.It may also shed light on the roles of existing pathways in host biology and provide valuable tools for metabolic engineering in plants and microbes[2].Unlike other major classes of plant natural products,such as terpenoids and polyketides,the formation of alkaloid scaffolds does not conform to a uniform chemical theme or depend on a singular enzyme class[3].A case in point is the Lycopodium alkaloids in the Lycopodiaceae family,where the enzymes responsible for their core scaffold construction remain unidentified[4].

关键词： Lycopodium alkaloid Carbonic anhydrase-like enzymes Biosynthesis

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Meridional deflection of global eddy propagation derived from tandem altimetry: Mechanism and implication

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Science China Earth Sciences 2024年第3期67卷 811-825页

作者： ge CHEN Xiaoyan CHEN Frontiers Science Center for Deep Ocean Multispheres and Earth System School of Marine TechnologyOcean University of ChinaQindao 266100China Laboratory for Regional Oceanography and Numerical Modeling Laoshan LaboratoryQindao 266237China

A common view on meridional deflection of eddy propagation is poleward for cyclones and equatorward for anticyclones. This widely accepted polarity-sensitive pattern has been increasingly undermined given that it is systematically violated on both zonal and regional scales as recently reported. Here, we approach the problem by exploring these violations in terms of eddy effects of spatiotemporal geostrophy, thermal fading, and flow dragging, yielding the following main conclusions.(1) The polarity-dependent deflection discrepancy is a pseudo feature resulting from a biased fit to the normalized eddy tracks which are spatially asymmetric(though azimuthally symmetric) between the two signs;Instead, the primary pattern of eddy deflection appears to be geographically correlated and polarity independent.(2) geostrophic adjustment plays a critical role in defining the meridional movement of an eddy. Specifically, a consistent poleward(equatorward) trajectory bending of spatially(temporally) ageostrophic eddies is observed irrespective of their polarity.(3) The mechanism of eddy deflection is also determined by its zonal propagation direction. Westward propagating eddies are substantially affected by thermal fading, while opposite ones by flow dragging. A realistic and comprehensive understanding of eddy deflection mechanisms serves as a significant contribution to the prediction of eddy trajectory, and the protection of ocean environment.

关键词： Mesoscale eddies Eddy propagation Eddy meridional deflection Satellite observation geostrophic adjustment

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Association between central serous chorioretinopathy and Helicobacter pylori infection: a systematic review and Meta-analysis

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International Journal of Ophthalmology(English edition) 2024年第6期17卷 1120-1127页

作者： Da-Wen Wu Fei-Peng Jiang ge ge Mei-Xia Zhang Department of Ophthalmology West China HospitalSichuan UniversityChengdu 610041Sichuan ProvinceChina Research Laboratory of Macular Disease West China HospitalSichuan UniversityChengdu 610041Sichuan ProvinceChina

AIM:To investigate the association between central serous chorioretinopathy(CSC)and Helicobacter pylori(Hp)by summarizing all available evidence.METHODS:The Scopus,Embase,EBSCO,PubMed,Web of Science,and Cochrane Library databases for all relevant studies published from inception to October 2022 were searched,and manually searched for relevant reference lists as a supplement.Studies investigating the association between CSC and Hp infection were included.Finally,8 case-control studies were included in the Meta-analysis after study selection.RESULTS:The results showed no significant correlation between Hp infection and CSC[odds ratio(OR)1.89,95%confidential interval(CI)0.58–6.15,I2=96%,P=0.29].After subgroup analysis based on the degree of development of the study(developing/developed countries),it was found that the results of the two subgroups were the same as the whole,and no significant difference between the two subgroups existed.Meta-regression showed that the effect of sample size on heterogeneity among studies was more prominent(Pgeneity.CONCLUSION:This Meta-analysis reveals no significant correlation between Hp infection and CSC,which still warrants further well-designed extensive sample studies to reach a more reliable conclusion and promote a better understanding of the treatment of CSC.

关键词： central serous chorioretinopathy Helicobacter pylori infection retinal diseases Meta-analysis

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Design of an automated robotic microinjection system for batch injection of zebrafish embryos and larvae

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Microsystems & Nanoengineering 2024年第1期10卷 89-103页

作者： Zhongyi Guo Nana Ai Wei ge Qingsong Xu Department of Electromechanical Engineering Faculty of Science and TechnologyUniversity of MacaoMacaoChina Department of Biomedical Sciences and Centre of Reproduction Development and Aging(CRDA)Faculty of Health SciencesUniversity of MacaoMacaoChina

This paper presents the design of a vision-based automated robotic microinjection system for batch injection of both zebrafish embryos and larvae.A novel visual recognition algorithm based on an automatic threshold and excessive dilatation is introduced to accurately identify the center of zebrafish embryos and larval yolks.A corresponding software system is developed using the producer-consumer model as the framework structure,and a friendly user interface is designed to allow operators to choose from a range of desired functions according to their different needs.In addition,a novel microstructural agarose device is designed and fabricated to simultaneously immobilize mixed batches of embryos and larvae.Moreover,a prototype microinjection system is fabricated by integrating hardware devices with visual algorithms.An experimental study is conducted to verify the performance of the robotic microinjection system.The results show that the reported system can accurately identify zebrafish embryos and larvae and efficiently complete batch microinjection tasks of the mixtures with an injection success rate of 92.05%in 13.88 s per sample.Compared with manual and existing microinjection systems,the proposed system demonstrates the merits of versatility,excellent efficiency,high success rate,high survival rate,and sufficient stability.

关键词： zebra automated hardware

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Essential Players in Cooperative Games with Graph Communication Structure

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Journal of the Operations Research Society of China 2024年第1期12卷 93-108页

作者： Guang Zhang Jing-Yi ge Business School University of Shanghai for Science and TechnologyShanghai200093China

A class of cooperative games with graph communication structure is studied in this paper by considering some important players,namely essential players.Under the assumption that only connected coalitions containing essential players are able to cooperate and obtain their worths,the class of graph games with essential players is proposed as well as an allocation rule.The proposed value follows the spirit of the Myerson value defined by applying the Shapley value on a modified game.Three properties,feasible component efficiency,the inessential component property,and fairness,are provided to fully characterize this value,where feasible component efficiency and fairness follows the same ideas of component efficiency and fairness for classical graph games,and the inessential component property says that the total payoffs of the players in a non-feasible component is zero.Moreover,some computational aspects of the proposed value and comparisons with disjunctive permission value for games with permission structure are also studied,respectively.

关键词： Cooperative game Graph structure Essential player Myerson value Computation Permission structure

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Theoretical study on the stability of nanobubbles and its verification in molecular dynamics simulation

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Particuology 2024年第4期87卷 99-105页

作者： Sheng Mi Chaofeng Hou Wei ge School of Chemical Engineering and Technology Tianjin UniversityTianjin300072China State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing.100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing100049China

The stability of vapor nanobubbles in bulk liquid was investigated theoretically and the critical bubble size was derived from macroscale thermodynamic equations,below which the system destabilizes with sharp drop in pressure.This critical size was quantitatively verified in molecular dynamic simulation using the Lennard-Jones model of argon,where stronger attraction between the molecules at lower density is found to contribute most to the drop of system pressure and,as the Laplace pressure on the curved bubble interface fails to balance the pressure difference across the interface,the bubbles become unstable.The theoretical model could be extended to other systems where reliable equations of state and interfacial tension are available.

关键词： Nanobubble Stability Phase diagram Critical size

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Establishment of a three-dimensional particle library for graded crushed stone based on a new aggregate morphology characterization method

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Journal of Traffic and Transportation Engineering(English Edition) 2024年第1期11卷 117-130页

作者： Haitao ge Aimin Sha Zhenqiang Han School of Future Transportation Chang'an UniversityXi'an 710064China University of Strasbourg INSA StrasbourgCNRSICubeUMR 7357Strasbourg F-67000France School of Highway Chang'an UniversityXi'an 710064China Key Laboratory for Special Area Highway Engineering of Ministry of Education Chang'an UniversityXi'an 710064China

The morphology of graded crushed stone(GCS)particles has an essential influence on the performance of aggregate mixtures.The impact of particle shape is a comprehensive effect that cannot be considered separately,leading to difficulties in establishing the relationship between the mixture properties and the aggregate morphology by using laboratory methods.The discrete element method(DEM)is an effective way widely adopted to reconstruct the morphology of particles and simulate performance tests of granular materials.However,selecting limited particles characterizing a real particle-assembly for simulation is still a challenge in current research due to the inherent rich variability of particle shapes.In this study,based on the acquisition of three-dimensional(3D)aggregate shapes by using laser scanning,ellipsoid index(EDI)translating the particle shape as a function of surface area,volume,and contour length is proposed to comprehensively evaluate aggregate morphology.Further,a particle library capable of characterizing aggregate morphology distribution is established based on the statistics of the corresponding morphological characteristics of particle samples.The model reliability is validated by carrying out a series of experimental and numerical penetration tests with nine different gradations.The established particle library can be used to model aggregate mixtures and the proposed simulation framework is promising for optimizing the mixture gradation design numerically.

关键词： Particle library Discrete element method 3D laser scanning Coarse aggregate Morphology characterization Gradation design

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Soft coarse-grained particle model for particle-fluid systems

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Particuology 2024年第1期84卷 178-193页

作者： Yanhao Ye Ji Xu Wei ge State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing100049China Innovation Academy for Green Manufacture Chinese Academy of SciencesBeijing100190China

By modeling a group of neighboring real particles as a single coarse-grained particle(CGP),discrete particle method(DPM)is now capable of simulating industrial-scale particle-fluid systems.However,a systematic approach to determine the CGP properties and develop their interaction models is still lacking,which casts uncertainty on the predictivity of the method.In this study,collisions between predefined particle groups are analyzed to construct kernel functions for modeling the CGPs and then the model parameters are determined by equating the statistical properties of the CGPs and the real particles in the physical process studied.This approach is implemented for homogeneous cooling of granular gas,then demonstrated effective in simulating experimental fluidized beds.

关键词： Coarse-grain(CG) Discrete particle method(DPM) Fluidized bed Multi-scale simulation

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geometry of holomorphic invariant strongly pseudoconvex complex Finsler metrics on the classical domains

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Science China Mathematics 2024年第8期67卷 1827-1864页

作者： Xiaoshu ge Chunping Zhong School of Mathematical Sciences Xiamen University

In this paper, a class of holomorphic invariant metrics is introduced on the irreducible classical domains of types Ⅰ-Ⅳ, which are strongly pseudoconvex complex Finsler metrics in the strict sense of Abate and Patrizio(1994). These metrics are of particular interest in several complex variables since they are holomorphic invariant complex Finsler metrics found in the literature which enjoy good regularity as well as strong pseudoconvexity and can be explicitly expressed to admit differential geometry studies. They are,however, not necessarily Hermitian quadratic as the Bergman metrics. These metrics are explicitly constructed via deformation of the corresponding Bergman metric on the irreducible classical domains of types Ⅰ-Ⅳ,respectively, and they are all proved to be complete K?hler-Berwald metrics. They enjoy very similar curvature properties as those of the Bergman metric on the irreducible classical domains, i.e., their holomorphic sectional curvatures are bounded between two negative constants and their holomorphic bisectional curvatures are always nonpositive and bounded below by negative constants, respectively. From the viewpoint of complex analysis,these metrics are analogs of Bergman metrics in complex Finsler geometry which do not necessarily have Hermitian quadratic restrictions in the sense of Chern(1996).

关键词： holomorphic invariant metric Kähler-Berwald metric irreducible classical domains

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