4,604 research outputs found
Muon-spin-relaxation and magnetic-susceptibility studies of effects of the magnetic impurity Ni on the Cu-spin dynamics and superconductivity in La_2-x_Sr_x_Cu_1-y_Ni_y_O_4_ with x = 0.13
Effects of the magnetic impurity Ni on the Cu-spin dynamics and
superconductivity have been studied in La_2-x_Sr_x_Cu_1-y_Ni_y_O_4_ with x =
0.13 changing y finely up to 0.10. Compared with the case of the nonmagnetic
impurity Zn, it has been found from the muon-spin-relaxation measurements that
a large amount of Ni is required to stabilize a magnetic order of Cu spins.
However, the evolution toward the stabilization of the magnetic order with
increasing impurity concentration is qualitatively similar to each other. The
area of the non-superconducting and slowly fluctuating or static region of Cu
spins around Ni has been found to be smaller than that around Zn, suggesting
that the pinning of rather long-ranged dynamical spin correlation such as the
so-called dynamical stripe by Ni is weaker than that by Zn. This may be the
reason why Zn destroys the superconductivity in the hole-doped high-T_c_
cuprates more markedly than Ni.Comment: 4 pages, 4 figures, accepted for publication in Phys. Rev.
Cu-spin dynamics in the overdoped regime of La_2-x_Sr_x_Cu_1-y_Zn_y_O_4_ probed by muon spin relaxation
Muon-spin-relaxation measurements have been performed for the partially
Zn-substituted La_2-x_Sr_x_Cu_1-y_Zn_y_O_4_ with y=0-0.10 in the overdoped
regime up to x=0.30. In the 3 % Zn-substituted samples up to x=0.27,
exponential-like depolarization of muon spins has been observed at low
temperatures, indicating Zn-induced slowing-down of the Cu-spin fluctuations.
The depolarization rate decreases with increasing x and almost no fast
depolarization of muon spins has been observed for x=0.30 where
superconductivity disappears. The present results suggest that the dynamical
stripe correlations exist in the whole superconducting regime of
La_2-x_Sr_x_CuO_4_ and that there is no quantum critical point at x~0.19.Comment: 6 pages, 5 figure
New Visible Light-triggered Photocatalytic Trifluoromethylation Reactions of Carbon‐carbon Multiple Bonds and (Hetero)aromatic Compounds
Visible-light-photocatalyzed methods employed insynthetic transformations present attractive properties such asenvironmentally friendly, safety, availability and excellent functionalgroup tolerance. In this venue, research on the visible-lightphotocatalytic incorporation of the trifluoromethyl CF3 moiety intoorganic substrates, in particular, has contributed to a clear evolutionof the very field of photocatalysis. Outer-sphere electron transfersbetween photocatalysts and trifluoromethyl sources supply CF3radicals efficiently in clean and controlled ways, capable of effectingnumerous synthetic transformations and functionalization on organicsubstrates and compounds with pharmacological activity instraightforward manners. Although this particular area is constantlyevolving and reviewed, the last five years have experienced anoutburst of seminal and significant photocatalytic trifluoromethylationexamples that are leading the way and opening new syntheticavenues. Recent review articles on Ru- and Ir- based photocatalytictrifluoromethylation reactions have borne witness of this evolution.Although this account will show the new Ru- and Ir-basedphotocatalytic trifluoromethylations, Sections 2 and 3 will alsoillustrate other photocatalytic systems, such as organic dyes, organicsemiconductors and newly-developed all-organic photocatalysts. All the known and reviewed strategies for photocatalytictrifluoromethylation reactions of olefins and (hetero)aromaticcompounds will not be discussed but will be summarized in twoFigures (Figures 4 and 5), and new examples (2015-present) will bepresented and discussed.Fil: Barata Vallejo, Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Orgánica; ArgentinaFil: Postigo, Jose Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Orgánica; Argentin
UPPER LIMB KINEMATICS OF BASEBALL BATTING TO DIFFERENT BALL SPEEDS
INTRODUCTION: Increasing bat velocity and accurately hitting the baseball are important for increasing hit ball velocity. Although there are studies on motion for increasing bat velocity, few studies discussed hitting accuracy in actual baseball batting. Therefore, the aim of this study was to analyze the strategies of upper limbs motion for accurately hitting the ball at different conditions of ball speed
Effect of Kinetic mechanisms of lower limbs on torso motion in baseball batting for different ball speeds
It is known that baseball batters adjust movements of the torso, and lower and upper limbs to hit the ball when ball course and speed vary. However, few studies investigated the effect of kinetic mechanisms of lower limbs on torso motion for different ball speeds. Therefore, the purpose of this study was to investigate effects of kinetic mechanisms of lower limbs on torso motion in baseball batting for different ball speeds
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