Mass formulas and thermodynamic treatment in the mass-density-dependent model of strange quark matter

The previous treatments for strange quark matter in the quark mass-density-dependent model have unreasonable vacuum limits. We provide a method to obtain the quark mass parametrizations and give a self-consistent thermodynamic treatment which includes the MIT bag model as an extreme. In this treatment, strange quark matter in bulk still has the possibility of absolute stability. However, the lower density behavior of the sound velocity is opposite to previous findings.Comment: Formatted in REVTeX 3.1, 5 pages, 3 figures, to appear in PRC6

Analysis of long-term depression in the Purkinje cell circuit (a model study)

In the cerebellum, long-term depression (LTD) plays a key function in sculpting neuronal circuits to store information, since motor learning and memory are thought to be associated with such long-term changes in synaptic efficacy. To better understand the principles of transmission of information in the cerebellum, we, in our model, distinguished different types of neurons (type 1- and type 2-like) to examine the neuronal excitability and analyze the interspike interval (ISI) bifurcation phenomenon in these units, and then built a Purkinje cell circuit to study the impact of external stimulation on LTD in this circuit. According to the results of computational analysis, both climbing fiber-Purkinje cell and granule cell-Purkinje cell circuits were found to manifest LTD; the external stimuli would influence LTD by changing both depression time and depression intensity. All of the simulated results showed that LTD is a very significant factor in the Purkinje circuit networks. Finally, to deliver the learning regularities, we simulated spike timing-dependent plasticity (STDP) by increasing the CaP conductance.У мозочку довготривала депресія (ДД) відіграє ключову роль у пристосуванні нейронних мереж до накопичення інформації, оскільки моторне навчання та пам’ять, як вважають, асоційовані з подібними тривалими змінами синаптичної ефективності. Намагаючись краще зрозуміти принципи передачі інформації в мозочку, в перебігу дослідження збудливості нервових клітин та аналізу феномена біфуркації міжімпульсних інтервалів у цих нейронах ми диференціювали в нашій моделі різні види нейронів (першого і другого типів). Потім була сформована модель нервової мережі клітини Пуркін̕ є для дослідження впливів зовнішньої стимуляції на ДД у такій мережі. Відповідно до результатів комп’ютерного аналізу, ДД проявляється і в мережі «ліаноподібне волокно–клітина Пуркін̕ є», і в мережі «гранулярна клітина–клітина Пуркін̕ є». Зовнішня стимуляція може впливати на ДД, змінюючи як час, так і інтенсивність депресії. Згідно з результатами моделювання, ДД є дуже істотним фактором при функціонуванні мереж, котрі містять у собі клітини Пуркін̕ є. Нарешті, ми, щоб виявити закономірності процесу навчання, за допомогою збільшення CaP-провідності моделювали пластичність, залежну від часу генерації піка (STDP)

A Simulation Study on the Effect of Cavity Shapes on the Penetration of Linear Shaped Charges with Curved Liners

The finite element models of curved-liner shaped charges penetrating aluminum-alloy thin plates were constructed with the ANSYS/LS-DYNA software to analyze the effect of cavity shapes on the charge penetration with curved liners. The cavity height, radius, and spatial dimensions were numerically simulated. Simulation results indicate that these properties are important factors in determining the penetration of curved-liner charges. The penetration depth exhibits an initial increase followed by a decrease with the fixed cavity radius. When the cavity height is fixed, the penetration depth decreases with the cavity radius. When the cavity is semicircular, the penetration depth first increases and then decreases with the cavity radius and height.Построены конечноэлементные модели кумулятивных зарядов со сложнопрофильной облицовкой, проникающих через тонкие пластины из алюминиевого сплава. Использовано программное обеспечение ANSYS/LS-DYNA для анализа влияния формы выемки на их проницаемость. Выполнены численные расчеты высоты, радиуса и пространственных размеров выемки. Показано, что эти характеристики являются важными факторами при определении проницаемости зарядов. Глубина проникновения увеличивается, а затем уменьшается с увеличением высоты выемки при постоянном радиусе. При фиксированной высоте глубина проникновения уменьшается с увеличением радиуса. При полуокружной выемке глубина проникновения увеличивается, затем уменьшается с увеличением ее радиуса и высоты

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

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

Investigation on wear and rolling contact fatigue of wheel-rail materials under various wheel/rail hardness ratio and creepage conditions

The wear and rolling contact fatigue of wheel-rail materials were investigated through varying wheel/rail hardness ratios (Hw/Hr) and creepages. The results indicated that with the Hw/Hr increasing from 0.927 to 1.218, the wheel wear rate reduced significantly in the case of Hw/Hr = 1.218, the rail wear rate showed an increasing trend. Both the wheel and rail wear rates increased as the creepage enlarged. The synergistic results of Hw/Hr and creepage caused a transition of the wear and damage mechanisms on the wheel-rail steels. Besides, the fatigue damage of ER7 and CL60 wheel materials was dominated by slender multi-layer cracks, while the fatigue cracks were short and contained lots of interlayer broken materials on C-class wheel steel