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Stress waves propagation in solids under high-speed liquid impact

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Science China(Physics,Mechanics & Astronomy) 2004年第6期47卷 752-766页

作者： j.e.Field Cavendish Laboratory Cambridge UniversityMadingly RoadCambridge CB3 0HEUK

An experiment of impact between 450 m/s water jets and polymethylme- thacrylate (PMMA) materials with complex surface geometry was conducted. The testing surfaces were a corner, step change, surface-breaking notch, inclined surface, etc. Stress waves propagation in the solid such as reflection, interference and diffraction was observed using polarized optics and an Imacon high speed camera (operating at both of 106 and 5×105 framing rates per second, fps). A damage test by the impact of the side jetting of an 850 m/s water jet was also carried out. It was found that stress waves propagation in solids depends not only on the surface geometry but also on the contact situation between liquid and solid. It was shown that the side jetting has sufficient damage potential although its head may consist of finer droplets. The results of this paper are useful to further analyze the dynamic stress state of solids under high-speed liquid impact.

关键词： high-speed liquid/solid impact, stress waves, mechanical property of solid, high-speed photography.

Faulty evidence for superconductivity in ac magnetic susceptibility of sulfur hydride under pressure

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National Science Review 2022年第6期9卷 43-44页

作者： j.e.Hirsch Department of Physics University of California

Sulfur hydride was reported to become superconducting at high pressure and temperature [1]. Posteriorly, Huang and coworkers measured its ac magnetic susceptibility [2], reportedly confirming that finding. According to Semenok and Oganov [3], their work ‘sets a new standard for experimental studies of superconductivity at high pressure’.Instead I argue here that the ac susceptibility measurements of Huang et al.

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Small extrachromosomal circular DNA in amyotrophic lateral sclerosis matter

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Neural Regeneration Research 2025年第5期20卷 1411-1413页

作者： Marcos j.Arauzo-Bravo Daniela Gerovska Matthias Schwab Alexandra Kretz Computational Biology and Systems Biomedicine Biodonostia Health Research InstituteSan SebastianSpain Basque Foundation for Science IKERBASQUEBilbaoSpainMax Planck Institute for Molecular BiomedicineComputational Biology and Bioinformatics GroupMünsterNorth Rhine-WestphaliaGermany Department of Cell Biology and Histology Faculty of Medicine and NursingUniversity of Basque Country(UPV/EHU)LeioaSpain Department of Neurology Jena University HospitalJenaThuringiaGermany

Comprehensive studies identify motor neuron spectrum disorders including amyotrophic lateral sclerosis(ALS)as globally rising fatal disorders with the highest prevalence in aging populations,influenced by ethnicity and ancestry(GBD 2016 Motor Neuron Disease Colla borators,2018).While~10% of diagnoses involve a family history(fALS),most cases are considered sporadic(sALS).However,population-based studies suggest that even cases without a common index mutation impart heritability(Ryan et al.,2019),indicating a crucial role of rare and as yet unknown genetic denominators.

关键词： amyotrophic sclerosis

Distributed Document Clustering Analysis Based on a Hybrid Method

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China Communications 2017年第2期14卷 131-142页

作者： j.e.judith j.jayakumari Noorul Islam Centre for Higher education KumaracoilIndia

Clustering is one of the recently challenging tasks since there is an *** amount of data in scientific research and commercial applications. High quality and fast document clustering algorithms are in great demand to deal with large volume of data. The computational requirements for bringing such growing amount data to a central site for clustering are complex. The proposed algorithm uses optimal centroids for *** clustering based on Particle Swarm Optimization(PSO).PSO is used to take advantage of its global search ability to provide optimal centroids which aids in generating more compact clusters with improved accuracy. This proposed methodology utilizes Hadoop and Map Reduce framework which provides distributed storage and analysis to support data intensive distributed applications. experiments were performed on Reuter's and RCV1 document dataset which shows an improvement in accuracy with reduced execution time.

关键词： distributed document clustering hadoop k-means PSO mapreduce

Fish embryo and juvenile size under hypoxia in the mouth- brooding African cichlid Pseudocrenilabrus multicolor

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Current Zoology 2012年第3期58卷 401-412页

作者： e.e. ReARDON L.j. CHAPMAN Department of Biology McGill University 1205 Dr. Penfield Ave Montreal Quebec H3A 1B 1 Canada Wildlife Conservation Society 2300 Southern Boulevard Bronx NY 10460 USA

We used a field survey and a laboratory rearing experiment to （a） examine response （size and survival） to life-long hypoxia in offspring of the African maternal mouth-brooding cichlid Pseudocrenilabrus multicolor victoriae （Seegers） and （b） explore the degree to which developmental response can be environmentaUy-induced. embryo size metrics were quantified in 9 field populations across a range of dissolved oxygen （DO） concentrations. In the laboratory, first generation （F1） broods of low-DO origin were reared under high or low DO. Brooding period was quantified for the mothers; and egg size, egg metabolic rate and juvenile size-at-release were quantified in their （F2） offspring. The F2 offspring were split and grown for 3 months post-release under high or low DO, and juvenile size and survival were quantified. In the field survey, across stages, embryos from low-DO field populations were shorter and weighed less than embryos from high-DO populations. In the laboratory experi- ment, F2 eggs and juveniles-at-release from mother＇s mouth did not differ in mass, length, survival regardless of development DO environment. However, juveniles diverged in size after leaving mother＇s mouth, exhibiting smaller size when grown under low DO. Size differences in embryo size across field populations and divergence in embryo size after release from the mother＇s mouth support predictions for smaller body size under hypoxia. There was no evidence for negative effects on survival of juveniles after 3 months. Brooding period was 16% shorter in females reared under low DO suggesting that hypoxia may accelerate embryo de- velopment. This work provides insights into how bearer fishes respond to hypoxic stress relative to fishes with no post-spawning parental care; a shorter brooding interval and smaller body size may provide an optimal solution to parent and embryo survival under hypoxia in brooding fishes [Current Zoology 58 （3）： 401-412, 2012].

关键词： African cichlid Lake Victoria Life-history Parental care Dissolved oxygen

In-port-plug transmission line design of the ITeR plasma position reflectometer

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Plasma Science and Technology 2020年第6期22卷 15-20页

作者： j MARTÍNeZ-FeRNÁNDeZ ÁCAPPA A SIMONeTTO T eSTRADA e De LA LUNA e j BLANCO Laboratorio Nacional de Fusión.CIeMAT Avda Complutense 40.Madrid 28040Spain CNR-ISTP via Cozzi 5320125 MilanoItaly

This work describes the microwave design of the transmission line housed in the in-port-plug region of the ITeR plasma position reflectometer(PPR).The design of the components of the inport-plug reflectometers(located in equatorial port-plug 10(ePP10) and in upper-port-plug 01(UPP01)) is *** a 3 D ray tracing code, the spatial position and optimum orientation angles of each set of emission and detection antennas were determined.A feasible path was then created from the obtained antenna positions and orientations to the primary vacuum *** tall waveguides were chosen to reduce ohmic *** to space constraints in the ITeR crowded environment, bends in oversized waveguides were unavoidable, and thus mode conversion was *** keep mode conversion losses at bay, hyperbolic secant curvature bends had to be used whenever ***, e-plane bends in tall waveguides proved to be especially critical, making it necessary to employ other approaches when higher bending angles were *** conversion results were obtained by evaluating the mode coupling *** losses have also been computed and their results compared with commercial simulators, obtaining a perfect agreement.

关键词： reflectometry microwave technology ITeR diagnostic

examining the use of narrative constructs in data videos

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Visual Informatics 2020年第1期4卷 8-22页

作者： Ruochen Cao Subrata Dey Andrew Cunningham james walsh Ross T.Smith joanne e.Zucco Bruce H.Thomas The School of Information Technology and Mathematical Science University of South AustraliaAustralia Department of Media University of AdelaideAustralia

Data videos are a highly impactful method of communication and are becoming a prevalent medium for communicating *** the majority of current research focuses on the cinematic aspects of data videos,very little is known about the narrative methodologies *** paper presents our insights derived from an initial exploration of this *** present a taxonomy based on the analysis of 70 existing data videos examining their narrative and visual *** propose that our taxonomy can be used to explain the characteristics or design of data *** this taxonomy,we present our observations,including the trend of popular technologies applied in current data videos,the under-utilization of promising methods,and highlight research opportunities in the field.

关键词： Narrative visualization Data videos Taxonomy Narrative approaches

effect of some operational variables on bubble size in a pilot-scale mechanical flotation machine

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journal of Central South University 2014年第3期21卷 1077-1084页

作者：张炜 j.e.Nesset j.A.Finch Mining and Mineral Resources Division Department of Business AdministrationChinalco China Copper Corporation Limited Department of Mining and Materials engineering McGill University

This work aims to provide a relationship of how the key operational variables of frother type and impeller speed affect the size of bubble （D32）. The study was performed using pilot-scale equipment （0.8 m^3） that is up to two orders of magnitude larger than equipment used for studies performed to date by others, and incorporated the key process variables of frother type and impeller speed. The results show that each frother family exhibits a unique CCC95-HLB relationship dependent on n （number of C-atoms in alkyl group） and m （number of propylene oxide group）. empirical models were developed to predict CCC95 from HLB associated with other two parameters a and ft. The impeller speed-bubble size tests show that D32 is unaffected by increased impeller tip speed across the range of 4.6 to 9.2 m/s （representing the industrial operating range）, although D32 starts to increase below 4.6 m/s. The finding is valid for both coalescing and non-coalescing conditions. The results suggest that the bubble size and bubble size distribution （BSD） being created do not change with increasing impeller speed in the quiescent zone of the flotation.

关键词： flotation bubble size operational variables critical coalescence concentration hydrophile-lipophile balance impellerspeed

Characterization of Magnetron Sputter CN_(x) Thin Films

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Chinese Physics Letters 1998年第2期15卷 120-122页

作者： ZHeNG Wei-tao j.e.Sundgren Department of Materials Science Jilin UniversityChangchun 130023 Department of Physics Linkoping UniversityS-58183 LinkopingSweden

Carbon nitride thin films were deposited at different substrate temperature(ST)by using reactive magnetron sputtering in a pure N_(2) discharge,and studied by laser Raman spectroscopy,x-ray photoelectron spectroscopy(XPS),and spectroscopic *** Raman spectra of the films show that I(D)/I(G)decreased with the increase of *** D bandposition shifted towards lower frequency,while the G bandposition shifted towards higher frequency as the ST *** XPS data exhibit that Nls binding states also depend on *** optical band gap of the films is found dropped from 0.22eV to 0.10eV with the increase of ST.

关键词： shifted films spectroscopic