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Breakup of Cavitation Bubbles within the Diesel Droplet

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Chinese Journal of Mechanical Engineering 2014年第1期27卷 198-204页

作者： l Ming NING Zhi YAN Kai FU juan SONG Yunchao SUN Chunhua College of Mechanical and Electrical Engineering Beijing Jiaotong University

Supercavitation in the diesel nozzle increases the instability of droplets in part due to the two-phase mixture, while the effect of cavitation bubbles on the instability of drops is still unclear. In order to investigate the breakup of cavitation bubbles within the diesel droplet, a new mathematical model describing the disturbance growth rate of the diesel bubble instability is developed. The new mathematical model is applied to predict the effects of fluids viscosity on the stability of cavitation bubbles. The predicted values reveal that the comprehensive effect of fluids viscosity makes cavitation bubbles more stable. Compared with the viscosities of air and cavitation bubble, the diesel droplet＇s viscosity plays a dominant role on the stability of cavitation bubbles. Furthermore, based on the modified bubble breakup criterion, the effects of bubble growth speed, sound speed, droplet viscosity, droplet density, and bubble-droplet radius ratio on the breakup time and the breakup radius of cavitation bubbles are studied respectively. It is found that a bubble with large bubble-droplet radius ratio has the initial condition for breaking easily. For a given bubble-droplet radius ratio （0.2）, as the bubble growth speed increases （from 2 m/s to 60 m/s）, the bubble breakup time decreases（from 3.59 gs to 0.17 ps） rapidly. Both the greater diesel droplet viscosity and the greater diesel droplet density result in the increase of the breakup time. With increasing initial bubble-droplet radius ratio （from 0.2 to 0.8）, the bubble breakup radius decreases （from 8.86 trn to 6.23 tm）. There is a limited breakup radius for a bubble with a certain initial bubble-droplet radius ratio. The mathematical model and the modified bubble breakup criterion are helpful to improve the study on the breakup mechanism of the secondary diesel droplet under the condition of supercavitation.

关键词： supercavitation instability diesel droplet cavitation bubbles secondary breakup

Plateau archives of lithosphere dynamics,cryosphere and paleoclimate:The formation of Cretaceous desert basins in east Asia

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Geoscience Frontiers 2022年第6期13卷 170-181页

作者： Chihua Wu juan Pedro Rodríguez-lópez M.Santosh State Key laboratory of Oil and Gas Reservoir Geology and Exploitation Chengdu University of TechnologyChengdu 610059China PAGODA Research Group(Plateau&Global Desert Basins Research Group) Institute of Sedimentary GeologyChengdu University of TechnologyChengdu 610059China Permafrost laboratory Department of GeographyUniversity of SussexFalmerBrighton BN19SJUnited Kingdom School of Earth Science and Resources China University of Geosciences29 Xueyuan RoadBeijing 100083China Department of Earth Sciences University of AdelaideSA 5005Australia

Southeastern Eurasia is a global window to the Cretaceous paleoclimate and lithosphere *** contains one of the most complete and complex sedimentary records of Mesozoic desert basins on planet *** this study,we perform the spatio-temporal tracking of 96 Cretaceous palaeoclimate indicators during 79 Myr which reveal that the plateau paleoclimate archives from East Asia resulted from an Early to Mid-Cretaceous ocean–atmosphere coupling and a shift to a preponderant role of late Cretaceous lithosphere dynamics and tectonic forcing on high-altitude depositional systems linked to the subduction margins of the Tethys and Paleo-Pacific realms beneath the Eurasian *** crustal response to tectonic processes linked with the spatio-temporal evolution of the Tethyan and Paleo-Pacific margins defined the configuration of major sedimentary basins on this *** significant increase and decrease in the number of active sedimentary basins that occur during the Cretaceous,from 16 in the Early Cretaceous,to 28 in the Mid-Cretaceous,and a decreasing to 20 sedimentary basins in the late Cretaceous,is a direct response of lithospheric dynamics associated with the two main subduction zones(Tethys and Pacific domains).A shift in subduction style from an Early Cretaceous Paleo-Pacific Plate slab roll back to a late Cretaceous flat-slab mode might have triggered regional plateau uplift,blocked intraplate volcanism,thus enhancing the denudation and sediment availability,and created wind corridors that led to the construction and accumulation of extensive late Cretaceous aeolian sandy deserts(ergs)that covered Mid-Cretaceous plateau *** the same time,plateau uplift associated with crustal thickening following terrane assembly in the Tethyan margin triggered altitudinal cryospheric processes in sandy desert *** of an active Cretaceous cryosphere in China include ValanginianHauterivian glacial debris flows,Early Aptian geochemical signature of melt w

关键词： Cretaceous Cryosphere Aeolian Plateau Subduction Asia

An unsupervised pattern recognition methodology based on factor analysis and a genetic-DBSCAN algorithm to infer operational conditions from strain measurements in structural applications

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Chinese Journal of Aeronautics 2021年第2期34卷 165-181页

作者： juan Carlos PERAFAN-lOPEZ Julian SIERRA-PEREZ Grupo de Investigacion en Ingenieria Aeroespacial Universidad Pontificia BolivarianaCircular 170-01Medellin 050031Colombia

Structural Health Monitoring(SHM) suggests the use of machine learning algorithms with the aim of understanding specific behaviors in a structural system. This work introduces a pattern recognition methodology for operational condition clustering in a structure sample using the well known Density Based Spatial Clustering of Applications with Noise(DBSCAN) *** methodology was validated using a data set from an experiment with 32 Fiber Bragg Gratings bonded to an aluminum beam placed in cantilever and submitted to cyclic bending loads under 13 different operational conditions(pitch angles). Further, the computational cost and precision of the machine learning pipeline called FA + GA-DBSCAN(which employs a combination of machine learning techniques including factor analysis for dimensionality reduction and a genetic algorithm for the automatic selection of initial parameters of DBSCAN) was measured. The obtained results have shown a good performance, detecting 12 of 13 operational conditions, with an overall precision over 90%.

关键词： Clustering DBSCAN Factor analysis FBGs Pattern recognition Strain field

Methods for discovery and characterization of cellulolytic enzymes from insects

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Insect Science 2010年第3期17卷 184-198页

作者： Jonathan D. Willis Cris Oppert juan l. Jurat-Fuentes Department of Entomology and Plant Pathology University of Tennessee Knoxville Tennessee USA

Cellulosic ethanol has been identified as a crucial biofuel resource due to its sustainability and abundance of cellulose feedstocks. However, current methods to obtain glucose from lignocellulosic biomass are ineffective due to recalcitrance of plant biomass. Insects have evolved endogenous and symbiotic enzymes to efficiently use lignocellulosic material as a source of metabolic glucose. Even though traditional biochemical methods have been used to identify and characterize these enzymes, the advancement of genomic and proteomic research tools are expected to allow new insights into insect digestion of cellulose. This information is highly relevant to the design of improved industrial processes ofbiofuel production and to identify potential new targets for development of insecticides. This review describes the diverse methodologies used to detect, quantify, purify, clone and express cellulolytic enzymes from insects, as well as their advantages and limitations.

关键词： biofuels cellulases cellulase discovery methods cellulase substrate insect digestive fluids lignocellulosic biomass

锆基金属有机框架捕获黄连中的生物碱类药物活性成分

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分析测试学报 2025年第1期44卷 188-194页

作者：司甜甜赵薇王慧张红玉刘小烨容蓉冯娟娟山东中医药大学药学院山东济南250355 济南大学化学化工学院山东济南250022

采用溶剂热法制备了锆基MOF-808,利用其结构优势实现了中药黄连中生物碱类药物活性成分的富集与捕获,并结合其结构特点探讨了其协同低共熔溶剂捕获生物碱类活性成分过程中的相互作用。通过优化孵育捕获等条件,对黄连粗提液中药根碱的回... 详细信息

采用溶剂热法制备了锆基MOF-808,利用其结构优势实现了中药黄连中生物碱类药物活性成分的富集与捕获,并结合其结构特点探讨了其协同低共熔溶剂捕获生物碱类活性成分过程中的相互作用。通过优化孵育捕获等条件,对黄连粗提液中药根碱的回收率达到85.78%,结合高效液相色谱技术建立了检测黄连粗提液中5种生物碱类活性成分的方法。方法的线性范围为0.1~300μg·l^(-1),检出限为0.02~0.05μg·l^(-1),相对标准偏差为0.40%~4.7%,加标回收率达到69.7%~128%。该研究实现了中药黄连中生物碱类活性成分的高效、快速富集与捕获,为MOFs材料在选择性捕获与富集中药有效成分等领域的研究提供了新思路。

关键词：金属有机框架选择性富集色谱分离生物碱活性成分黄连

BASKETBAll SCORING IN NBA GAMES:AN EXAMPlE OF COMPlEXITY

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Journal of Systems Science & Complexity 2013年第1期26卷 94-103页

作者： DE SA GUERRA Yves MARTíN GONZAlEZ juan Manuel SARMIENTO MONTESDEOCA Samuel RODRIGUEZ RUIZ David ARJONIllA lóPEZ Nieves GARCíA-MANSO juan Manuel Departament of Phisical Education University of Las Palmas de Gran Canaria Departament of Physics University of Las Palmas de Gran Canaria

Scoring in a basketball game is a highly dynamic, non-linear process. NBA teams try to be more and more competitive each season. For instance, they incorporate into their rosters the best players in the world. This and other mechanisms concur to make the scoring process in NBA games exciting and rarely predictable. This paper is to study the behavior of timing and scoring in basketball gaines. The authors analyze all the games in five NBA regular seasons （2005-06, 2006-07, 2007-08, 2008-09, 2009-10）, for a total of 6150 games. Scoring does not behave uniformly; therefore, the authors also analyze the distributions of the differences in points in the basketball games. To further analyze the behavior of the tail of the distribution, the authors also carry out a semilog-plot and a log-log plot to verify whether this trend approaches a Poisson distribution or a Pl. This paper reveals different areas of behavior related to the score, with specific instances of time that could be considered tipping points of the game. The presence of these critical points suggests that there are phase transitions where the dynamic scoring of the games varies significantly.

关键词： Complexity NBA non-linear Poisson power law.

Observation and Simulation of Abnormal Transmittance over Yangbajing,Tibet

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Atmospheric and Oceanic Science letters 2014年第3期7卷 190-197页

作者： WANG lei-Di lü Da-Ren HUO juan Key laboratory of Middle Atmosphere and Global Environmental Observation (lAGEO) Institute of Atmospheric PhysicsChinese Academy of Sciences University of Chinese Academy of Sciences

Defining abnormal transmittance as the case where the magnitude of the shortwave flux transmittance is greater than 1.0,the authors used surface solar irradiance and all-sky images obtained at the Yangbajing site in Tibet to analyze the reasons for the occurrence of abnormal shortwave flux *** on the International Intercomparision of Three-Dimensional Radiation Code(I3RC) Monte Carlo community model of three-dimensional radiative transfer,the authors also performed simulations at a nonabsorbing wavelength and an absorbing wavelength through a stratocumulus and a cumulus *** results showed the detection of abnormal transmittance on more than half the days,and the maximum transmittance was *** probability of the occurrence of abnormal transmittance appeared to be largest in summer,and on a daily basis was mainly at about noon local *** transmittance mainly appeared when clear sky and clouds co-existed,especially at the edges of broken clouds and nearby regions with clear-sky *** flux transmittance decreased as the solar zenith angle increased.

关键词： three-dimensional cloudsshortwave flux transmittanceMonte Carlo modelTibet

Survival of potential probiotic isolated from fermented tea leaf and encapsulated in multilayer beads stored in makiang(Cleistocalyx nervosum ***)juice

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Food Bioscience 2022年第6期50卷 389-395页

作者： Paramaporn Kerdsup Passarin Hattayapichat juan l.Silva Sumate Tantratian Department of Food Technology Faculty of ScienceChulalongkorn UniversityBKK10330Thailand Program in Biotechnology Faculty of ScienceChulalongkorn UniversityBKK10330Thailand Department of Biotechnology and Agricultural Product Faculty of Agricultural Product Innovation and TechnologySrinakharinwirot UniversityNakhonnayok26120Thailand Department of Food Science Nutrition and Health PromotionMississippi State UniversityMS39762USA

Cleistocalyx nervosum *** juice or makiang juice has high content of acid and phenolic compounds which are detrimental to probiotic *** screening of potential probiotic with acid production and phenolic tolerant bacteria from fermented tea leaves revealed 5 isolates which were identified using 16s rRNA sequencing procedure and found similarity to the strain of lactobacillus plantarum in GenBank database at 98–100%.The storage of 5 isolates and 6 probiotics in makiang juice for 24 h was indicated that *** MF105 and TISTR 2074 showed the least reduction of 30.10±1.25 and 61.41±2.37%,*** cultures were encapsulated in 2%alginate bead(Al),Al+single-layer of gelatin(ACG),and Al+double-layer of gelatin(ACGD).They were kept in makiang juice at 4°*** physico-chemical characteristics of beads in makiang juice illustrated that the accumulation of phenolic compounds was faster than the pH decreasing and caused initial reduction of bacterial *** ACGD beads absorbed slower and accumulated less amount of phenolic compounds than *** were the most effective in cell protection,the viability of encapsulated MF105 and TISTR2074 were prolonged to more than 7 and 4 days,*** adaptation in combination with encapsulation enhanced the survival of probiotic cell in sub-lethal stress *** had shown that increasing the coating layer provided a chance to improve lethality of probiotic bacteria.

关键词： Anthocyanin Alginate gel Refrigeration temperature Adaptation

A novel method for improving cerussite sulfidization

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International Journal of Minerals,Metallurgy and Materials 2016年第6期23卷 609-617页

作者： Qi-cheng Feng Shu-ming Wen Wen-juan Zhao Qin-bo Cao Chao lü State Key laboratory of Complex Nonferrous Metal Resources Clean Utilization Kunming University of Science and Technology Kunming Metallurgical Research Institute

Evaluation of flotation behavior, solution measurements, and surface analyses were performed to investigate the effects of chloride ion addition on the sulfidization of cerussite in this study. Micro-flotation tests indicate that the addition of chloride ions prior to sulfidization can significantly increase the flotation recovery of cerussite, which is attributed to the formation of more lead sulfide species on the mineral surface. Solution measurement results suggest that the addition of chloride ions prior to sulfidization induces the transformation of more sulfide ions from pulp solution onto the mineral surface by the formation of more lead sulfide species. X-ray diffraction and energy-dispersive spectroscopy indicate that more lead sulfide species form on the mineral surface when chloride ions are added prior to sulfidization. These results demonstrate that the addition of chloride ions prior to sulfidization can significantly improve the sulfidization of cerussite, thereby enhancing the flotation performance.

关键词： cerussite sulfidization chloride surface analysis