Catálogo de publicaciones - revistas

<jats:p> Spectroscopic data begin to elucidate the initial steps in the biosynthesis of the hydrogenase active site. <jats:named-content content-type="related-content"> [Also see Report by <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6169" page="424" related-article-type="in-this-issue" vol="343" xlink:href="10.1126/science.1246572"> Kuchenreuther <jats:italic>et al.</jats:italic> </jats:related-article> ] </jats:named-content> </jats:p>

<jats:p>Advances in satellite observations and model development are needed to disentangle the complex interactions of aerosols and clouds and their effects on climate.</jats:p>

<jats:p> The compound eyes of mantis shrimps see color in a fundamentally different way from other animals. <jats:named-content content-type="related-content"> [Also see Report by <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6169" page="411" related-article-type="in-this-issue" vol="343" xlink:href="10.1126/science.1245824"> Thoen <jats:italic>et al.</jats:italic> </jats:related-article> ] </jats:named-content> </jats:p>

<jats:p> Combining surface- and bulk-sensitive experimental probes may help to solve the complexity underlying high-temperature superconductivity. <jats:named-content content-type="related-content"> [Also see Reports by <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6169" page="390" related-article-type="in-this-issue" vol="343" xlink:href="10.1126/science.1242996"> Comin <jats:italic>et al.</jats:italic> </jats:related-article> and <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6169" page="393" related-article-type="in-this-issue" vol="343" xlink:href="10.1126/science.1243479"> da Silva Neto <jats:italic>et al.</jats:italic> </jats:related-article> ] </jats:named-content> </jats:p>

<jats:p> A cytosolic protein that senses fragments of HIV-1 DNA triggers the death of uninfected CD4 T cells. <jats:named-content content-type="related-content"> [Also see Report by <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6169" page="428" related-article-type="in-this-issue" vol="343" xlink:href="10.1126/science.1243640"> Monroe <jats:italic>et al.</jats:italic> </jats:related-article> ] </jats:named-content> </jats:p>

<jats:p> The understanding of the origin of superconductivity in cuprates has been hindered by the apparent diversity of intertwining electronic orders in these materials. We combined resonant x-ray scattering (REXS), scanning-tunneling microscopy (STM), and angle-resolved photoemission spectroscopy (ARPES) to observe a charge order that appears consistently in surface and bulk, and in momentum and real space within one cuprate family, Bi <jats:inline-formula> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi mathvariant="normal"> </mml:mi> <mml:mn>2</mml:mn> </mml:msub> </mml:mrow> </mml:math> </jats:inline-formula> Sr <jats:inline-formula> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi mathvariant="normal"> </mml:mi> <mml:mrow> <mml:mn>2</mml:mn> <mml:mo>−</mml:mo> <mml:mi>x</mml:mi> </mml:mrow> </mml:msub> </mml:mrow> </mml:math> </jats:inline-formula> La <jats:inline-formula> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi mathvariant="normal"> </mml:mi> <mml:mi>x</mml:mi> </mml:msub> </mml:mrow> </mml:math> </jats:inline-formula> CuO <jats:inline-formula> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi mathvariant="normal"> </mml:mi> <mml:mrow> <mml:mn>6</mml:mn> <mml:mo>+</mml:mo> <mml:mi>δ</mml:mi> </mml:mrow> </mml:msub> </mml:mrow> </mml:math> </jats:inline-formula> . The observed wave vectors rule out simple antinodal nesting in the single-particle limit but match well with a phenomenological model of a many-body instability of the Fermi arcs. Combined with earlier observations of electronic order in other cuprate families, these findings suggest the existence of a generic charge-ordered state in underdoped cuprates and uncover its intimate connection to the pseudogap regime. </jats:p>

<jats:p> Besides superconductivity, copper-oxide high-temperature superconductors are susceptible to other types of ordering. We used scanning tunneling microscopy and resonant elastic x-ray scattering measurements to establish the formation of charge ordering in the high-temperature superconductor Bi <jats:sub>2</jats:sub> Sr <jats:sub>2</jats:sub> CaCu <jats:sub>2</jats:sub> O <jats:sub>8+x</jats:sub> . Depending on the hole concentration, the charge ordering in this system occurs with the same period as those found in Y-based or La-based cuprates and displays the analogous competition with superconductivity. These results indicate the similarity of charge organization competing with superconductivity across different families of cuprates. We observed this charge ordering to leave a distinct electron-hole asymmetric signature (and a broad resonance centered at +20 milli–electron volts) in spectroscopic measurements, indicating that it is likely related to the organization of holes in a doped Mott insulator. </jats:p>

<jats:p> The study of gas-phase reaction dynamics has advanced to a point where four-atom reactions are the proving ground for detailed comparisons between experiment and theory. Here, a combined experimental and theoretical study of the dissociation dynamics of the tetra-atomic FH <jats:sub>2</jats:sub> O system is presented, providing snapshots of the F + H <jats:sub>2</jats:sub> O → HF + OH reaction. Photoelectron-photofragment coincidence measurements of the dissociative photodetachment (DPD) of the F <jats:sup>¯</jats:sup> (H <jats:sub>2</jats:sub> O) anion revealed various dissociation pathways along different electronic states. A distinct photoelectron spectrum of stable FH–OH complexes was also measured and attributed to long-lived Feshbach resonances. Comparison to full-dimensional quantum calculations confirms the sensitivity of the DPD measurements to the subtle dynamics on the low-lying FH <jats:sub>2</jats:sub> O potential energy surfaces over a wide range of nuclear configurations and energies. </jats:p>

<jats:p>Sedimentary basins increase the damaging effects of earthquakes by trapping and amplifying seismic waves. Simulations of seismic wave propagation in sedimentary basins capture this effect; however, there exists no method to validate these results for earthquakes that have not yet occurred. We present a new approach for ground motion prediction that uses the ambient seismic field. We apply our method to a suite of magnitude 7 scenario earthquakes on the southern San Andreas fault and compare our ground motion predictions with simulations. Both methods find strong amplification and coupling of source and structure effects, but they predict substantially different shaking patterns across the Los Angeles Basin. The virtual earthquake approach provides a new approach for predicting long-period strong ground motion.</jats:p>