Study on the chaotic dynamics in yaw-pitch-roll coupling of asymmetric rolling projectiles with nonlinear aerodynamics

To predict the coning motion forms of a rolling projectile with configurational asymmetries, the nonlinear characteristics for the system are investigated in this paper. The nonlinear dynamic model of rolling projectiles in coning motion is built by considering the nonlinear aerodynamics and roll orientation-dependent aerodynamics. The configurational asymmetry is modeled as a periodically parametric excitation in order to study its effect on the periodic response stability of the rolling projectile. Numerical continuation method is resorted to determine the parametric zone for the steady motions, and the possible stable rotational speeds are discussed. The numerical simulations, Lyapunov exponent spectrum analysis and Poincare sections are performed to confirm the existence of chaotic coning motion. The results shown in this study not only contribute to an in-depth understanding for the nonlinear dynamics of rolling projectiles but also provide an important reference for the further study of the control design for the yaw-pitch-roll coupling of asymmetric rolling projectiles with nonlinear aerodynamics

Relative transcript levels of <i>Epas1</i> in XX, XO and XY oocytes collected from ovaries at 10 and 30 days after birth.

<p>“Growing oocytes” were selected for their diameter between 40 and 50 µm. “Fully grown oocytes” were denuded from oocyte-cumulus complexes of antral follicles. The transcript levels were normalized against the mean of two β-actin controls. Each column indicates the mean ± SEM (n = 3). A and B above columns denote statistical differences at P<0.01 by paired students t-test.</p

Bi-directional communication with the cumulus cells is involved in the deficiency of XY oocytes in the components essential for proper second meiotic spindle assembly

AbstractThe oocyte becomes competent for embryonic development by involving mutual communication with cumulus cells (CCs) during folliculogenesis. How this communication takes place under physiological conditions is not fully understood. Current study examined oocyte–CCs communication in the XY sex-revered female mouse. We have previously found that the XY oocyte is defective in its cytoplasm, causing abnormal MII-spindle assembly and a failure in embryonic development. Our present study showed that transcript levels of Pfkp, Pkm2 and Ldh1 involved in glycolysis were lower in the CCs surrounding XY oocytes than in those surrounding XX oocytes. ATP contents in XY oocytes were also lower than those in XX oocytes, suggesting that lower glycolytic gene expression in CCs resulted in lower ATP contents in the enclosed oocyte. Co-culture of oocytectomized CC-oocyte complexes (COCs) with denuded oocytes showed that XY oocytes were less efficient than XX oocytes in promoting glycolytic gene expression in CCs. Furthermore, both glycolytic gene expression levels in CCs and ATP contents in oocytes of XY COCs increased to similar levels to those of XX COCs after culture for 20h in the presence of milrinone (=preincubation), which prevented spontaneous oocyte maturation. By increasing ATP levels in XY oocytes by either COC preincubation or ATP microinjection into oocytes prior to in vitro maturation, an improvement in MII-spindle assembly was observed. We conclude that the XY oocyte produces lesser amounts of paracrine factors that affect its companion CCs, which in turn make the ooplasm deficient in its components, including ATP, essential for MII-spindle assembly

The Presence of the Y-Chromosome, Not the Absence of the Second X-Chromosome, Alters the mRNA Levels Stored in the Fully Grown XY Mouse Oocyte

<div><p>The oocytes of B6.Y^TIR sex-reversed female mouse mature in culture but fail to develop after fertilization because of their cytoplasmic defects. To identify the defective components, we compared the gene expression profiles between the fully-grown oocytes of B6.Y^TIR (XY) females and those of their XX littermates by cDNA microarray. 173 genes were found to be higher and 485 genes were lower in XY oocytes than in XX oocytes by at least 2-fold. We compared the transcript levels of selected genes by RT-PCR in XY and XX oocytes, as well as in XO oocytes missing paternal X-chromosomes. All genes tested showed comparable transcript levels between XX and XO oocytes, indicating that mRNA accumulation is well adjusted in XO oocytes. By contrast, in addition to Y-encoded genes, many genes showed significantly different transcript levels in XY oocytes. We speculate that the presence of the Y-chromosome, rather than the absence of the second X-chromosome, caused dramatic changes in the gene expression profile in the XY fully-grown oocyte.</p> </div

Ionic liquid functionalized electrospun gel polymer electrolyte for use in a high-performance lithium metal battery

The ability to suppress the formation and proliferation of lithium dendrites is an important endeavour towards the successful commercialization of lithium metal batteries as high energy storage devices. The use of gel polymer electrolytes is one of the most promising pathways to solving this problem and obtaining high performance. Here, we propose a novel gel polymer electrolyte (GPE), in which a nanostructured ionic liquid (IL), silica nanoparticle-tethered 1-methyl-1-propylpiperidinium bis(trifluoromethanesulfonyl) imide (SiO2PPTFSI), is first introduced into a gel polymer electrolyte matrix based on poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) prepared by electrospinning, followed by plasticization in a fluoroethylene carbonate (FEC) electrolyte. After being incorporated with the nanostructured IL, this novel GPE exhibits good mechanical properties, an enhanced electrolyte uptake (552 wt%) and a high ionic conductivity (0.64 mS cm(-1)) and lithium ion transference number (t(Li+) = 0.60). In addition, it suppresses lithium dendrite formation and exhibits stable plating/striping cycles over 1200 hours in a symmetric lithium cell. More importantly, it is electrochemically stable up to 5.1 V (vs. Li/Li+), making it practical for use in LiNi0.5Mn1.5O4 systems with a much better cycle stability and rate capability relative to those of Celgard with a liquid electrolyte or GPE based on PVDF-HFP. The Li/LiNi0.5Mn1.5O4 cell with the novel GPE exhibits an initial discharge capacity of 119 mA h g(-1) at 1C, a capacity retention of 92.1% after 460 cycles, and a high reversible capacity of 74 mA h g(-1) at 6C. Therefore, the use of a nanostructured IL-modified GPE presents a promising way to enhance the cycle performance and safety of lithium metal cells

RT-PCR detection of X-encoded gene transcripts in XX, XO and XY oocytes.

<p>A. Agarose gel electrophoresis stained with ethidium bromide. S, 100 bp ladders. B. Relative transcript levels. In each set of experiment, the transcript levels were normalized against the mean of two β-actin controls. Each column indicates the mean ± SEM (n = 6 for <i>Xiap</i> and n = 3 for others except for <i>Usp9x</i> in XO, n = 1). a and b above columns indicate statistical differences at P<0.05 by paired students t-test.</p

Fluid Phase Equilib.

Two low viscous ionic liquids (ILs), 1-(2-hydroxyethyl)-3-methyl-imidazolium dicyanamide ([C(2)OHmim][DCA]) and 1-butyl-3-methylimidazolium ([Bmim][DCA]) were selected to mixed with aqueous 30 wt% monoethanolamine (MEA) for CO2 absorption. The solubility of CO2 in the aqueous mixtures of MEA + ILs was measured over a range of CO2 partial pressure of 10-800 kPa and ILs concentrations from 10 to 50 wt% at 313.15K and 333.15 K. Correlations of solubility as a function of CO2 partial pressure have been conducted with deviation of +/- 1.5%. Moreover, the density and viscosity of pure ILs and MEA + ILs + H2O systems with different IL mass fractions were measured at temperature varying from 293.15 to 333.15 K. (C) 2014 Elsevier B.V. All rights reserved.Two low viscous ionic liquids (ILs), 1-(2-hydroxyethyl)-3-methyl-imidazolium dicyanamide ([C(2)OHmim][DCA]) and 1-butyl-3-methylimidazolium ([Bmim][DCA]) were selected to mixed with aqueous 30 wt% monoethanolamine (MEA) for CO2 absorption. The solubility of CO2 in the aqueous mixtures of MEA + ILs was measured over a range of CO2 partial pressure of 10-800 kPa and ILs concentrations from 10 to 50 wt% at 313.15K and 333.15 K. Correlations of solubility as a function of CO2 partial pressure have been conducted with deviation of +/- 1.5%. Moreover, the density and viscosity of pure ILs and MEA + ILs + H2O systems with different IL mass fractions were measured at temperature varying from 293.15 to 333.15 K. (C) 2014 Elsevier B.V. All rights reserved

Ionic liquid functionalized electrospun gel polymer electrolyte for use in a high-performance lithium metal battery

The ability to suppress the formation and proliferation of lithium dendrites is an important endeavour towards the successful commercialization of lithium metal batteries as high energy storage devices. The use of gel polymer electrolytes is one of the most promising pathways to solving this problem and obtaining high performance. Here, we propose a novel gel polymer electrolyte (GPE), in which a nanostructured ionic liquid (IL), silica nanoparticle-tethered 1-methyl-1-propylpiperidinium bis(trifluoromethanesulfonyl) imide (SiO2PPTFSI), is first introduced into a gel polymer electrolyte matrix based on poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) prepared by electrospinning, followed by plasticization in a fluoroethylene carbonate (FEC) electrolyte. After being incorporated with the nanostructured IL, this novel GPE exhibits good mechanical properties, an enhanced electrolyte uptake (552 wt%) and a high ionic conductivity (0.64 mS cm(-1)) and lithium ion transference number (t(Li+) = 0.60). In addition, it suppresses lithium dendrite formation and exhibits stable plating/striping cycles over 1200 hours in a symmetric lithium cell. More importantly, it is electrochemically stable up to 5.1 V (vs. Li/Li+), making it practical for use in LiNi0.5Mn1.5O4 systems with a much better cycle stability and rate capability relative to those of Celgard with a liquid electrolyte or GPE based on PVDF-HFP. The Li/LiNi0.5Mn1.5O4 cell with the novel GPE exhibits an initial discharge capacity of 119 mA h g(-1) at 1C, a capacity retention of 92.1% after 460 cycles, and a high reversible capacity of 74 mA h g(-1) at 6C. Therefore, the use of a nanostructured IL-modified GPE presents a promising way to enhance the cycle performance and safety of lithium metal cells.</p