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Secondary neurogenesis and telencephalic organization in zebrafish and mice: a brief review

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Integrative Zoology 2009年第1期4卷 123-133页

作者： mario f.WULLIMANN Department of Biology II Ludwig-Maximilians-UniversityMunich-MartinsriedGermany

Most zebrafish neurodevelopmental studies have focused on the embryo,which is characterized by primary neurogenesis of mostly transient *** neurogenesis becomes dominant in the hatching larva,when major brain parts are established and begin to *** developmental period allows for a comparative analysis of zebrafish brain organization with amniotes at equivalent stages of *** a particular time window,the early forebrains of mice(Embyronic stage[E]12.5/13.5 days[d])and zebrafish(3 d)reveal highly comparable expression patterns of genes involved in neurogenesis,for example proneural and other transcription factors(Neurogenin1,NeuroD,Mash1/Zash1a and Pax6).further topological correspondences are seen in the expression of LIM and homeobox genes,such as Lhx6/7,Tbr2 and *** this analysis is extended to gamma-aminobutyric acid/glutamic acid decarboxylase(GABA/GAD)cell patterns during this critical time window,an astonishing degree of similarity between the two species is again seen,for example regarding the presence of GABA/GAD cells in the subpallium,with the pallium only starting to be invaded by such cells from the ***,the expression of proneural and other genes correlates with GABA cell patterns(***1/Zash1a gene expression in GABA-positive and Neurogenin1/NeuroD in GABA-negative telencephalic regions)in mice and *** from additional vertebrates,such as Xenopus,are also highly consistent with this ***,the vertebrate forebrain appears to undergo a phylotypic stage of secondary neurogenesis,characterized by regionally separated GABAergic(inhibitory)versus glutamatergic(excitatory)cell production sites,which are obscured later in development by tangential *** period is highly advantageous for molecular neuroanatomical cross-species comparisons.

关键词： basal ganglia cortex subpallium tangential migration gamma-aminobutyric acid GABA.

Investigation on the influence of the initial RDX crystal size on the performance of shaped charge warheads

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Defence Technology（防务技术） 2019年第5期15卷 802-807页

作者： f.Majiet f.j.Mostert Rheinmetall Denel Munition Somerset WestSouth Africa Centre for Scientific&Industrial Research PretoriaSouth Africa

Copper lined wave shaped shaped charges of particular design and liner metallurgy were used to investigate the effect of explosive crystal size on the resultant shaped charge jet *** A3 with RDX of three different average crystal sizes,i.e.30μm,100μm and 300μm were used in the *** other parameters in the charge were kept constant and in particular,care was given to obtain consistent dimensional quality and liner microstructure,in order to prohibit the variation of other *** flash-X-ray diagnostics were used in field tests to obtain the jet parameters from multiple firings of similar *** is found that the varying crystal size of the RDX has a marginal influence in the total jet length of the ***,it is also found that there is less variation between firings in the jet parameters for jets from the charges loaded with the crystal size of 100 μm.

关键词： shaped size crystal

Implementation of a Roughness Element to Trip Transition in Large-eddy Simulation

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journal of Thermal Science 2015年第1期24卷 30-36页

作者： j.Boudet j.-f.Monier f.Gao LMfA Ecole Centrale de Lyon Université de Lyon–UMR CNRS 5509 69134 Ecully Cedex France PhD.Candidate Université de Lyon–UMR CNRS 5509 69134 Ecully Cedex France

In aerodynamics, the laminar or turbulent regime of a boundary layer has a strong influence on friction or heat transfer. In practical applications, it is sometimes necessary to trip the transition to turbulent, and a common way is by use of a roughness element （e.g. a step） on the wall. The present paper is concerned with the numerical im- plementation of such a trip in large-eddy simulations. The study is carried out on a flat-plate boundary layer con- figuration, with Reynolds number Rex=l.3x 106. first, this work brings the opportunity to introduce a practical methodology to assess convergence in large-eddy simulations. Second, concerning the trip implementation, a volume source term is proposed and is shown to yield a smoother and faster transition than a grid step. Moreover, it is easier to implement and more adaptable. finally, two subgrid-scale models are tested： the WALE model of Nic0ud and Ducros （flow Turbul. Combust., vol. 62, 1999） and the shear-improved Smagorinsky model of Ldv^que et al. （j. fluid Mech., vol. 570, 2007）. Both models allow transition, but the former appears to yield a faster transition and a better prediction of friction in the turbulent regime.

关键词： large-eddy simulation boundary layer roughness element transition tripping

Surface morphology and impurity distribution of electron beam recrystallized silicon films on low cost substrates for solar cell absorber

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Rare Metals 2006年第Z1期25卷 195-200页

作者： GROMBALL f MüLLER j Department of Mikrosystemtechnik Technische Universitt Hamburg-Harburg Hamburg 21073 Germany

A line shaped electron beam recrystallised polycrystalline silicon film on the low cost substrate was investigated for the use of the solar cell absorber. The applied EB energy density strongly influences the surface morphology of the film system. Lower EB energy density results in droplet morphology and the rougher SiO2 capping layer due to the low fluidity. With the energy increasing, the capping layer becomes smooth and continuous and less and small pinholes form in the silicon film. Tungstendisilicide (WSi2) is formed at the interface tungsten/silicon but also at the grain boundaries of the silicon. Because of the fast melting and cooling of the silicon film, the eutectic of silicon and tungstendisilicide mainly forms at the grain boundary of the primary silicon dendrites. The SEM-EDX analysis shows that there are no chlorine and hydrogen in the area surrounding a pinhole after recrystallization because of outgassing during the solidification.

关键词： polycrystalline silicon film solar cell recrystallization energy surface morphology outgassing

Applying rock mass classifications to carbonate rocks for engineering purposes with a new approach using the rock engineering system

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journal of Rock Mechanics and Geotechnical Engineering 2017年第2期9卷 364-369页

作者： Gioacchino francesco Andriani mario Parise Dipartimento di Scienze della Terra e Geoambientali Università degli Studi di Bari Aldo MoroVia E. Orabona n. 4Bari 70125Italy

Classical rock mass classification systems are not applicable to carbonate rocks,especially when these are affected by karst *** applications to such settings could therefore result in outcomes not representative of the real stress-strain *** this study,we propose a new classification of carbonate rock masses for engineering purposes,by adapting the rock engineering system(RES) method by Hudson for fractured and karstified rock masses,in order to highlight the problems of implementation of geomechanical models to carbonate *** new approach allows a less rigid classification for carbonate rock masses,taking into account the local properties of the outcrops,the site conditions and the type of engineering work as well.

关键词： Rock mass classification Carbonates Karst Rock engineering system(RES)

Characterization of Phases in an As-cast Copper-Manganese-Aluminum Alloy

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journal of Materials Science & Technology 2006年第6期22卷 779-784页

作者： j.Iqbal f.Hasan f.Ahmad Department of Metallurgical and Materials Engineering University of Engineering and TechnologyLahorePakistan

Copper-manganese-aluminum （CMA） alloys, containing small additions of fe, Ni, and Si, exhibit good strength and remarkable corrosion resistance against sea water. The alloys are used in as-cast condition, and their microstructure can show wide variations. The morphology, crystallography and composition of the phases presented in an as-cast （CMA） alloy of nominal composition Cu-14%Mn-8%Al-3%fe-2%Ni were investigated using optical, electron optical, and microprobe analytical techniques. The as-cast microstructure consisted of the grains of fcc α and bcc β-phases alongwith intermetallic precipitates of various morphologies. The room temperature microstructure exhibited four different types of precipitates inside the α-grains： the ＇large＇ dendritic-shaped particles and the cuboid-shaped precipitates, which were rich in fe and Mn and had an fcc structure, while the ＇small＇ dendritic-shaped particles and the globular precipitates were based on feaAI and had DO3 structure. These four different morphologies of intermetallic precipitates exhibited discrete orientation-relationships with the α-matrix. The β-grains only contained very small cuboid shaped precipitates, which could only be resolved through transmission electron microscopy. These precipitates were found to be based on fe3Al and had the DO3 structure.

关键词： Orientation relationship DO3 structure Intermetallic phases

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Chinese Annals of Mathematics,Series B 2002年第2期23卷 253-266页

作者： j.f.RODRIGUES CMAf/Universidade

This paper presents new results for strong solutions and their coincidence sets of the obstacle problem for linear hyperbolic operators of first order. An inequality similar to the LewyStampacchia ones for elliptic and parabolic problems is shown. Under nondegeneracy conditions the stability of the coincidence set is shown with respect to the variation of the data and with respect to approximation by semilinear hyperbolic problems. These results are applied to the asymptotic stability of the evolution problem with respect to the stationary coercive problem with obstacle.

关键词： Hyperbolic obstacle problem Linear hyperbolic operator Strong solution

Laser induced photo-detachment of O2 in DC discharge

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Plasma Science and Technology 2018年第7期20卷 98-105页

作者： j r legorreta j l patiNo f b yousif Centro de Investigacion en Ciencias Universidad Autonoma del Estado de Morelos.Av.UniversidadNo.1001 Col.Chamilpa Cuemavaca MorelosMexico

Determination of the negative ion number density of O2 and O in a DC discharge of oxygen plasma was made employing Langmuir probe in conjunction with eclipse laser photo- detachment technique. The temporal evolution of the extra electrons resulting from the photo- detachment of O2- and O- were used to evaluate the negative ion number density. The ratio of O2 number density to O varied from 0.03 to 0.22. Number density of both O~ and O increased with increasing power and decreased as the pressure was increased. Electron number density was evaluated from the electron energy distribution function （EEDf） using the I-V recorded characteristic curves. Electron temperature between 2 and 2.7 eV were obtained. Influence of the 02（al△g） metastable state is discussed.

关键词： electronegative plasma electron temperature Langmuir probe negative ion number density

Long-term experimental study on gravitational sedimentation of water aluminum oxide nanofluid at different volumetric concentrations

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International journal of Sediment Research 2023年第3期38卷 303-315页

作者： mario Misale johan Augusto Bocanegra Annalisa Marchitto DIME-Department of Mechanics Energetics Management and Transportation Thermal Engineering and Environmental Conditioning Division University of Genoa

The stability of nanofluids is critical in engineering applications. The sedimentation of the nanoparticles in the base fluid limits the stability of the nanofluid. By measuring the absorbance of a visible laser through water aluminum oxide nanofluids it is possible to observe the evolution of the sedimentation process. A simple experimental setup consisting of a thin closed test cavity（0.8 mm or 1.5 mm thickness）filled with nanofluid and a set of laser diodes-photodiodes pairs was used in the experiments to determine the absorbance and the local volumetric concentration. The evolution of the local volumetric concentration of the nanofluid was measured at 13 height positions along the test cavity. five initial volumetric concentrations of aluminum oxide（Al2O3; 0.5%, 1.0%, 1.5%, 2.0%, 3.0% and 4.0%） were considered. Data and digital photos were acquired for a total time lapse of 260 days. The results were independent of the container thickness. The same general trend was consistent for all the initial volumetric concentrations, i.e., the sedimentation rate decreases in time. The time evolution of the volumetric concentration was compared with results from a modified Mason-Weaver model. The comparison was possible by setting a variable sedimentation velocity in the model, suggesting that the sedimentation is affected by the dynamics of nanoparticle clusters with diverse sizes produced by agglomeration.

关键词： Pure nanofluid Aluminum oxide Nanoscale alumina particles Colloid sedimentation Nanoparticle settling Mason-Weaver model