Journal Covers

Profound bias- and time-dependent changes in the electronic structure of graphene-based supercapacitor electrodes are demonstrated under operating conditions via a combination of in operando x-ray spectroscopy and ab initio modeling by J.R.I. Lee and co-workers. The evolution in electronic structure reflects changes in the surface chemistry and morphology induced by polarization of the electrode-electrolyte interface and points to distinct pseudocapacitive and electric-double-layer capacitive channels for charge storage. Read more »

Work featured on Applied Optics cover from ALS Beamline 11.3.2. Field-dependent wavefront aberration distribution of an extreme ultraviolet single-lens zone-plate microscope, recovered by the gradient descent algorithm customized for partially coherent imaging and targeted for fast and accurate retrieval. Read more »

The synthesis and structural characterization of a diboryl triaryloctabromocorrole complex fills in a missing link in the family of diboron porphyrinoids. DFT calculations suggest that a strongly electron-withdrawing corrole ligand is required to stabilize the diboryl complex relative to the partially hydrolyzed diboron corrole complexes previously observed. New monoboryl corrole complexes are described, which do not have counterparts in porphyrin chemistry and are stabilized by internal F···H hydrogen bonding. Read more »

Platinum has been inserted into corroles for the first time and three oxidized PtIV(corrole˙2−)ArAr′ complexes have been structurally characterized. The Soret maxima of these complexes exhibit an unusually strong dependence on the meso-aryl substituents on the corrole, indicating aryl → corrole˙2− charge transfer character in these transitions. Read more »

Nacre–the iridescent inner lining of many mollusk shells– has a unique strcuture that is remarkably resistant to fracture. The nacre featured on this cover is from Haliotis laevigata with average layer thickness 470-nm. The colors represent crystal orientationthe crystal lattice tilts across tablets.left stack all tablets are yellow, hence all aragonite crystals are co-oriented. Read more »

Pictured is an illustration of several nuclear pore complexes (NPCs) embedded in a cell nucleus. NPCs act as gatekeepers between a cell’s cytoplasm and its nucleus. Based on crystallographic analyses, Sozanne R. Solmaz et al. uncover the molecular mechanism that underlies the large changes in diameter of NPCs and suggest a “ring cycle” mechanism for dilating and constricting the central NPC channel. The model could explain the ability of NPCs to accommodate transport substrates of a large size range and rapidly adjust to cellular transport needs. Read more »

This schematic of x-ray scattering is from a spiral antiferromagnet with a spin structure that gives rise to domains with jamming behavior. Using resonant magnetic x-ray photon correlation spectroscopy, this research shows that the domains of a spiral antiferromagnet enter a jammed state at the onset of long-range order. Researchers found that slow thermal fluctuations of the domain walls exhibit a compressed exponential relaxation with an exponent of 1.5 found in a wide variety of solid-like jammed systems and can be qualitatively explained in terms of stress release in a stressed network. As the temperature decreases, the energy barrier for fluctuations becomes large enough to arrest further domain wall fluctuations, and the domains freeze into a spatial configuration within 10 K of the Néel temperature. The relaxation times can be fitted with the Vogel-Fulcher law as observed in polymers, glasses, and colloids, thereby indicating that the dynamics of domain walls in an ordered antiferromagnet exhibit some of the universal features associated with jamming behavior. Read more »