Publications

Abstract Solid–solid interfacial processes greatly affect the performance of electronic and composite materials, but probing the dynamics of buried interfaces is challenging and often involves lengthy or invasive sample preparation. We show that bilayer nanoribbons—made here of tin dioxide and copper—are convenient structures for observing as‐made interfaces as they respond to changing temperature in a transmission electron microscope (TEM). At low temperatures (<200 °C), differential thermal expansion causes the bilayers to bend when heated or cooled, with the motion determined by the extent of Cu–SnO 2 epitaxy. At higher temperatures, we are able to watch—in real time and with nanometer resolution—a progression of grain growth, interdiffusion, island formation, solid‐state chemical reactions, and melting. This novel TEM geometry is readily applicable to other nanoribbon/coating combinations and is well suited to observing interfacial phenomena driven thermally or by the application of mechanical, electrical, or magnetic forces.

In 2012, the share of California's Gross State Product consumed by healthcare was 15.4%, and approximately 50% of healthcare spending went to care for 5% of the population.To address such cost challenges as well as to improve quality of care and patient outcomes, a group of California's private and public sector healthcare leaders, with academic and analytical expertise provided by the University of California, Berkeley's School of Public Health, came together in a collaboration known as the Berkeley Forum for Improving California's Healthcare Delivery System.This Report lays out the Forum's Vision: A rapid shift towards risk-adjusted global payments and coordinated care provided in large, integrated systems.Furthermore, the Forum supports the implementation of seven initiatives, such as the greater use of patient-centered medical homes and palliative care, as well as increased physical activity.Together, these initiatives are estimated to reduce healthcare spending in the state by $110 billion (or $800 per household per year) between 2013 and 2022.These savings would bend the cost curve, reducing the expected share of Gross State Product consumed by healthcare, from the estimated 17.1% to 16.5% in 2022.

Major depressive disorder is positively associated with popular music exposure and negatively associated with reading print media such as books. Further research elucidating the directionality and strength of these relationships may help advance understanding of the relationships between media use and MDD.

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

The influence of physical and chemical properties of Pt/TiO2, Pd/TiO2, and Pt/GaN metal−semiconductor Schottky diodes on the yield of collected hot electron flow (number of hot electrons per product molecule) was investigated. We measured both the chemicurrent (electron flow) and chemical turnover rate during oxidation of carbon monoxide (at pressures of 100 Torr of O2 and 40 Torr of CO in the 373−513 K range) using reaction systems equipped for simultaneous reaction rate and current measurements. The chemicurrent was found to be correlated with the turnover rate and can be used to detect the turnover rate for the three diodes. Thermoelectric current was observed in the presence of O2 or CO gas in the absence of catalytic reaction. The chemicurrent was observed only under catalytic reaction condition. The chemicurrent yield of Pt/GaN ((3.5 ± 0.8) × 10-3) was higher than that of Pt/TiO2 or Pd/TiO2 ((2−3) × 10-4) by 1 order of magnitude. We found that the metal−semiconductor interface structure (roughness, grain size, and step−terrace) is important in controlling the magnitude of chemicurrent yield.

Abstract The application of nanoscale electrical and biological devices will benefit from the development of nanomanufacturing technologies that are high‐throughput, low‐cost, and flexible. Utilizing nanomaterials as building blocks and organizing them in a rational way constitutes an attractive approach towards this goal and has been pursued for the past few years. The optical near‐field nanoprocessing of nanoparticles for high‐throughput nanomanufacturing is reported. The method utilizes fluidically assembled microspheres as a near‐field optical confinement structure array for laser‐assisted nanosintering and nanoablation of nanoparticles. By taking advantage of the low processing temperature and reduced thermal diffusion in the nanoparticle film, a minimum feature size down to ≈100 nm is realized. In addition, smaller features (50 nm) are obtained by furnace annealing of laser‐sintered nanodots at 400 °C. The electrical conductivity of sintered nanolines is also studied. Using nanoline electrodes separated by a submicrometer gap, organic field‐effect transistors are subsequently fabricated with oxygen‐stable semiconducting polymer.

Heterogeneous catalysts that contain bimetallic nanoparticles may undergo segregation of the metals, driven by oxidizing and reducing environments. The structure and composition of core-shell Rh 0.5 Pd 0.5 and Pt 0.5 Pd 0.5 nanoparticle catalysts were studied in situ, during oxidizing, reducing, and catalytic reactions involving NO, O 2 , CO, and H 2 by x-ray photoelectron spectroscopy at near-ambient pressure. The Rh 0.5 Pd 0.5 nanoparticles underwent dramatic and reversible changes in composition and chemical state in response to oxidizing or reducing conditions. In contrast, no substantial segregation of Pd or Pt atoms was found in Pt 0.5 Pd 0.5 nanoparticles. The different behaviors in restructuring and chemical response of Rh 0.5 Pd 0.5 and Pt 0.5 Pd 0.5 nanoparticle catalysts under the same reaction conditions illustrates the flexibility and tunability of the structure of bimetallic nanoparticle catalysts during catalytic reactions.

Na energy storage technology is strategically attractive for large scale applications such as grid energy storage. Here, we show that there is a clear relation between the Jahn-Teller activity of a transition metal ion at the end of charge and the mobility of Na in a cathode material. This is particularly important as mobility at the end of charge limits the capacity of current materials. Hence, by using this classical piece of physics in the battery world, it is possible to create higher capacity Na-cathode materials. Even more exciting is that the ideal element to impart this effect on cathodes is Fe, which is the least expensive of the transition metal oxides and can therefore enable low cost cathode materials.

Fast-evolving machine learning (ML) workloads have increasing requirements for networking. However, host network transport on RDMA NICs is hard to evolve, causing problems for ML workloads. For example, single-path RDMA traffic is prone to flow collisions that severely degrade collective communication performance. We present UCCL, an extensible software transport layer to evolve GPU networking. UCCL decouples the data path and control path of existing RDMA NICs and efficiently runs the control-path transport on host CPUs. This software extensibility brings in transport innovations that cannot be achieved in hardware for ML workloads, e.g., a multipath transport to resolve flow collisions. ML collectives atop UCCL achieve up to 4.5x higher performance compared to existing RDMA NICs.

The stable coexistence of insulating and metallic phases in strained vanadium dioxide (VO₂) has garnered significant research interest due to the intriguing phase transition phenomena. However, the temporal behavior of charge carriers in different phases of VO₂ remains elusive. Herein, we employ near-field optical nanoscopy to capture nanoscale alternating phase domains in bent VO₂ nanobeams. By conducting transient measurements across the different phases, we observed a prolonged carrier recombination lifetime in the metallic phase of VO₂, accompanied by an accelerated diffusion process. Our findings reveal nanoscale carrier dynamics in VO₂ nanobeams, offering insights that can facilitate further investigations into phase-change materials and their potential applications in sensing and microelectromechanical devices.