Catálogo de publicaciones - revistas

<jats:title>Defect-enhanced energy storage</jats:title> <jats:p> Dielectric capacitors are vital components of electronics and power systems. The thin-film materials of which capacitors are composed are usually optimized by changing the material composition. However, Kim <jats:italic>et al.</jats:italic> found that postprocessing an already effective thin-film dielectric by high-energy ion bombardment further improved the material because of the introduction of specific types of defects that ultimately improved the energy storage performance. The results suggest that postprocessing may be important for developing the next generation of capacitors. </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="6499" page="81" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abb0631">81</jats:related-article> </jats:p>

<jats:title>A gas junction</jats:title> <jats:p> In superconductors, electrons form a macroscopic wave function that has a definite phase. If two superconductors with different wave function phases are placed in contact with each other through an insulating link, a current will flow through this so-called Josephson's junction without any external voltage. Luick <jats:italic>et al.</jats:italic> and Kwon <jats:italic>et al.</jats:italic> observed an analogous phenomenon in a setup that involved two reservoirs of superfluid Fermi gases. Both groups measured the so-called current-phase relation: the dependence of the magnitude of the current on the relative phase. By tuning an external magnetic field, they were able to study how the interactions between fermions affected the nature of the superfluid state. </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="6499" page="89" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.aaz2342">89</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6499" page="84" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.aaz2463">84</jats:related-article> </jats:p>

<jats:title>A gas junction</jats:title> <jats:p> In superconductors, electrons form a macroscopic wave function that has a definite phase. If two superconductors with different wave function phases are placed in contact with each other through an insulating link, a current will flow through this so-called Josephson's junction without any external voltage. Luick <jats:italic>et al.</jats:italic> and Kwon <jats:italic>et al.</jats:italic> observed an analogous phenomenon in a setup that involved two reservoirs of superfluid Fermi gases. Both groups measured the so-called current-phase relation: the dependence of the magnitude of the current on the relative phase. By tuning an external magnetic field, they were able to study how the interactions between fermions affected the nature of the superfluid state. </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="6499" page="89" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.aaz2342">89</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6499" page="84" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.aaz2463">84</jats:related-article> </jats:p>

<jats:title>Using hydrocarbons as reagents</jats:title> <jats:p> Adding small alkyl groups to complex molecules usually relies on alkyl halide reagents. Laudadio <jats:italic>et al.</jats:italic> now report a convenient method to add ethane and propane directly across conjugated olefins with no prefunctionalization or byproducts (see the Perspective by Oksdath-Mansilla). The C–H bond scission in this hydroalkylation is accomplished by a decatungstate photocatalyst that also acts as a hydrogen atom transfer agent to complete the process. The reaction, optimized under flow conditions, works with methane as well, albeit with lower efficiency. </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="6499" page="92" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abb4688">92</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6499" page="34" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abc6168">34</jats:related-article> </jats:p>

<jats:title>Stable perovskites with ionic salts</jats:title> <jats:p> Ionic liquids have been shown to stabilize organic-inorganic perovskite solar cells with metal oxide carrier-transport layers, but they are incompatible with more readily processible organic analogs. Lin <jats:italic>et al.</jats:italic> found that an ionic solid, a piperidinium salt, enhanced the efficiency of positive-intrinsic-negative layered perovskite solar cells with organic electron and hole extraction layers. Aggressive aging testing showed that this additive retarded segregation into impurity phases and pinhole formation in the perovskite layer. </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="6499" page="96" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.aba1628">96</jats:related-article> </jats:p>

<jats:title>Sourcing HIV-1 infection</jats:title> <jats:p> HIV-1 has a multitude of strain variants, but sexual transmission of HIV-1 is assumed to result from productive infection by only one virus particle. Knowing the genetics of the virus strains that are transmitted could be crucial for developing successful vaccine strategies. Using epidemiological and genetic data from 112 pairs of sexual partners, Villabona-Arenas <jats:italic>et al.</jats:italic> found that individuals with acute infections are more likely to transmit multiple founder virus strains. In a phylodynamic approach that integrated phylogenetic analysis of sequence data with simulation of a transmission chain, the authors showed that multiple variant transmission is doubled during the first 3 months of infection irrespective of whether transmission was heterosexual or by men who have sex with men. </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="6499" page="103" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.aba5443">103</jats:related-article> </jats:p>