244 research outputs found

    Morphology and Orientation Selection of Non-Metallic Inclusions in Electrified Molten Metal

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    The effect of electric current on morphology and orientation selection of non-metallic inclusions in molten metal has been investigated using theoretical modelling and numerical calculation. Two geometric factors, namely the circularity (fc) and alignment ratio (fe) were introduced to describe the inclusions shape and configuration. Electric current free energy was calculated and the values were used to determine the thermodynamic preference between different microstructures. Electric current promotes the development of inclusion along the current direction by either expatiating directional growth or enhancing directional agglomeration. Reconfiguration of the inclusions to reduce the system electric resistance drives the phenomena. The morphology and orientation selection follows the routine to reduce electric free energy. The numerical results are in agreement with our experimental observations

    The Chinese Hospitality Industry: A perspective article

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    This paper illustrates the logics shifting in the Chinese hotel industry since1949 and offers a better understanding of how and why the Chinese hotel industry has evolved into its present situation. The logic evolution and future trends in this market were also discussed

    Removal of MnS inclusions in molten steel using electropulsing

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    A method using electropulsing to separate inclusions from molten steel is developed, based on the differences in electrical properties between the inclusions and liquid metal. The inclusions have different electrical resistivity from that of the liquid steel and hence are expelled to the surface of the metal by electropulsing. In comparison with the as-solidified untreated steel, the size of the inclusion is significantly larger at the surface of the molten steel due to the enhanced agglomeration. Moreover, the technique is efficient in eliminating particles smaller than 20 μm

    Effects of different probiotics on the gut microbiome and metabolites in the serum and caecum of weaning piglets

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    The objective of the study was to determine the effects of antibiotics, yeast culture (YC), and Lactobacillus culture (LC) on the gut microbiome and metabolites in the serum and caecum of weaning piglets. Twenty-four weaning piglets were divided into four treatment groups: control, antibiotic (1% chlortetracycline), 1.8% yeast culture (YC), and 1.6% Lactobacillus culture groups (LC). Each group had six replicated pens with one pig per pen. Feed and water were available ad libitum. Dietary supplementation with antibiotics, YC and LC increased the abundance of phylum, Firmicutes, and decreased the abundance of phylum, Proteobacteria. Beneficial bacteria such as Lactobacillus and Megasphaera in YC and LC groups increased, whereas the proportion of Shigella was decreased. Genera Alloprevotella and Lachnospira were biomarkers in the control and antibiotic groups, respectively. Phylum, Bacteroidetes, and genus, Collinsella, were biomarkers in the YC group, and Mitsuokella, Anaerotruncus, Syntrophococcus and Sharpea were biomarkers in the LC group. Dietary supplementation with different probiotics changed the serum and caecum metabolite profiles too. Antibiotic supplementation increased the levels of D-mannose, D-glucose, and hexadecanoic acid in the serum, and the levels of myo-inositol, D-mannose and benzenepropanoic acid in the caecum. LC increased the concentrations of D-mannose, cis-9-hexadecenoic acid and heptadecanoic acid in caecum compared with the control group. YC and LC supplementation in the weaning diet could improve the abundance of beneficial bacteria by changing the concentrations of some metabolites in the serum and caecum. Therefore, dietary supplementation with YC or LC could be used as additives instead of antibiotics in weaning piglets.Keywords: antibiotic; lactobacillus culture; yeast culture; high-throughput sequencing; gas chromatography mass spectrometr

    Glueballs, gluon condensate, and pure glue QCD below T_c

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    A quasiparticle description of pure glue QCD thermodynamics at T<T_c is proposed and compared to recent lattice data. Given that a gas of glueballs with constant mass cannot quantitatively reproduce the early stages of the deconfinement phase transition, the problem is to identify a relevant mechanism leading to the observed sudden increase of the pressure, trace anomaly, etc. It is shown that the strong decrease of the gluon condensate near T_c combined with the increasing thermal width of the lightest glueballs might be the trigger of the phase transition.Comment: 5 pages, 5 figures; analysis refined in v2, explanations added; v3 to appear in EPJ

    Search for the Chiral Magnetic Effect in Au+Au collisions at sNN=27\sqrt{s_{_{\rm{NN}}}}=27 GeV with the STAR forward Event Plane Detectors

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    A decisive experimental test of the Chiral Magnetic Effect (CME) is considered one of the major scientific goals at the Relativistic Heavy-Ion Collider (RHIC) towards understanding the nontrivial topological fluctuations of the Quantum Chromodynamics vacuum. In heavy-ion collisions, the CME is expected to result in a charge separation phenomenon across the reaction plane, whose strength could be strongly energy dependent. The previous CME searches have been focused on top RHIC energy collisions. In this Letter, we present a low energy search for the CME in Au+Au collisions at sNN=27\sqrt{s_{_{\rm{NN}}}}=27 GeV. We measure elliptic flow scaled charge-dependent correlators relative to the event planes that are defined at both mid-rapidity η<1.0|\eta|<1.0 and at forward rapidity 2.1<η<5.12.1 < |\eta|<5.1. We compare the results based on the directed flow plane (Ψ1\Psi_1) at forward rapidity and the elliptic flow plane (Ψ2\Psi_2) at both central and forward rapidity. The CME scenario is expected to result in a larger correlation relative to Ψ1\Psi_1 than to Ψ2\Psi_2, while a flow driven background scenario would lead to a consistent result for both event planes[1,2]. In 10-50\% centrality, results using three different event planes are found to be consistent within experimental uncertainties, suggesting a flow driven background scenario dominating the measurement. We obtain an upper limit on the deviation from a flow driven background scenario at the 95\% confidence level. This work opens up a possible road map towards future CME search with the high statistics data from the RHIC Beam Energy Scan Phase-II.Comment: main: 8 pages, 5 figures; supplementary material: 2 pages, 1 figur

    Point View in Bird and Flower Painting

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    在中国传统绘画中,点景是极其重要的一种表达方式。石涛所研究的绘画问题中,情感、理性、力量都是不可缺少的,如何恰当地运用这三者,却有可能导致完全不同的创作结果。而点景正是这三者的集合点,不仅要用心灵去感受自然对象的内在精神,不能因为对象的限制而使感受层次也受到限制,把眼睛之受升华为心理之受。在绘画作品中合理地运用点景能使画家的情感与物象更加融合,画家自身的主观感受在画面上得到充分的体现,以一种小的特殊表现符号流露出画家作品里表达的象征倾向和审美概念,对画面的构图及意境有着画龙点睛的作用。本文以花鸟画点景为研究对象,重点介绍了点景的表现与意义;进一步阐述了点景在传统花鸟画构成中的作用,着重论述其在...The “point view” is extremely important as a means of expression in the traditional Chinese painting. Emotion, rationality and power are essential in the Shi Tao studied painting, and how to properly use them may lead to the creation of a completely different result. For the reason that “point view” is a collection of these three points, shouldn’t we only use the soul to feel the inner spirit of n...学位:文学硕士院系专业:艺术教育学院美术系_美术学学号:1862007115166

    Electropulsing-induced strengthening of steel at high temperature

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    Electropulsing usually promotes a metastable phase to evolve towards its equilibrium state. This work reports an alternative case, where electropulsing promotes the decomposition of the stable δ-phase in duplex stainless steel at high temperature. This decomposition enables both the γ-phase and the σ-phase in the steel to survive and hence to strengthen it at high temperature. The hardness of the quenched sample with electropulsing treatment is 49.4% higher than that without electropulsing treatment. A fundamental understanding of the observation is developed

    κ-carbide hardening in a low-density high-Al high-Mn multiphase steel

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    κ-carbide hardening in a ferrite–austenite duplex low-density Fe–Mn–Al–C steel has been investigated as a function of annealing temperature in a range between 500 °C and 900 °C. Fine microstructure containing thin lamellar κ-carbides in austenite and dispersed nano-scale particulate κ-carbides in ferrite were formed in a temperature below 600 °C. This led to a high hardness. The steel was soften drastically at the higher annealing temperature. This is due to the formation of boundary κ-carbides, discontinuous coarsened κ-carbides, and spheroidized κ-carbides. The κ-carbides inside ferrite grain were transformed into austenite at 800 °C. The κ-carbides within austenite grain were dissolved at 900 °C. The κ-carbides are found to have a close to Nishiyama–Wasserman orientation relationship with the ferrite matrix
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