Catálogo de publicaciones - revistas

<jats:title>Solving the problems with Li-air batteries</jats:title> <jats:p> Li-air batteries come as close as possible to the theoretical limits for energy density in a battery. By weight, this is roughly 10 times higher than conventional lithium-ion batteries and would be sufficient to power cars with a range comparable to those with gasoline engines. But engineering a Li-air battery has been a challenge. Liu <jats:italic>et al.</jats:italic> managed to overcome the remaining challenges: They were able to avoid electrode passivation, turn limited solvent stability into an advantage, eliminate the fatal problems caused by superoxides, achieve high power with negligible degradation, and even circumvent the problems of removing atmospheric water. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6260" page="530" related-article-type="in-this-issue" vol="350" xlink:href="10.1126/science.aac7730">530</jats:related-article> </jats:p>

<jats:title>Bedrock weathering runs to the hills</jats:title> <jats:p> Fractures in bedrock drive the breakdown of rock into soil. Soil makes observations of bedrock processes challenging. St. Clair <jats:italic>et al.</jats:italic> combined a three-dimensional stress model with geophysical measurements to show that bedrock erosion rates mirror changes in topography (see the Perspective by Anderson). Seismic reflection and electromagnetic profiles allowed mapping of the bedrock fracture density. The profiles mirror changes in surface elevation and thus provide a way to study the critical zone between rock and soil. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6260" page="534" related-article-type="in-this-issue" vol="350" xlink:href="10.1126/science.aab2210">534</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6260" page="506" related-article-type="in-this-issue" vol="350" xlink:href="10.1126/science.aad2266">506</jats:related-article> </jats:p>

<jats:title>Visualizing conducting domain walls</jats:title> <jats:p> When a metal undergoes a phase transition and becomes insulating, it sometimes also becomes magnetically ordered. It is possible that some metallicity survives along the boundaries of magnetic domains, the so-called domain walls, but the question is difficult to address directly in experiments. Ma <jats:italic>et al.</jats:italic> did just that by mapping out the conductance of the material Nd <jats:sub>2</jats:sub> Ir <jats:sub>2</jats:sub> O <jats:sub>7</jats:sub> in its low-temperature magnetic insulating phase, using microwave impedance microscopy. The magnetic domain walls showed up clearly in the images as regions of high conductance. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6260" page="538" related-article-type="in-this-issue" vol="350" xlink:href="10.1126/science.aac8289">538</jats:related-article> </jats:p>

<jats:title>Cooling to see the effects of disorder</jats:title> <jats:p> In sufficiently strong external magnetic fields, thin superconducting films typically become insulating. The presence of disorder can affect this phase transition. Theorists have proposed that disorder can cause the so-called Griffiths singularity, where the behavior of the system is determined by a small number of superconducting islands that form above the critical magnetic field. Xing <jats:italic>et al.</jats:italic> observed a signature of such a singularity in thin films of gallium by analyzing transport data taken at very low temperatures (see the Perspective by Markovic). In this regime, thermal fluctuations were not strong enough to homogenize the system, which allowed the rare islands to form. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6260" page="542" related-article-type="in-this-issue" vol="350" xlink:href="10.1126/science.aaa7154">542</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6260" page="509" related-article-type="in-this-issue" vol="350" xlink:href="10.1126/science.aad4136">509</jats:related-article> </jats:p>

<jats:title>Comparing lab and field estimates</jats:title> <jats:p>What do Swiss high-school students and Eastern European seasonal laborers have in common? When the former are tasked with stuffing questionnaires into envelopes in a classroom setting and the latter are employed to pick fruit in the United Kingdom, both work harder in the presence of their peers. Herbst and Mas reanalyzed the results of 35 such studies, either experiments carried out under controlled conditions or empirical studies based on data collected in the field (see the Perspective by Charness and Fehr). Encouragingly, they found that the magnitude of the spillover effect—how much harder a worker works when other workers are alongside—was the same.</jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6260" page="545" related-article-type="in-this-issue" vol="350" xlink:href="10.1126/science.aac9555">545</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6260" page="512" related-article-type="in-this-issue" vol="350" xlink:href="10.1126/science.aad4343">512</jats:related-article> </jats:p>