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Abstract: —J. Blunden and T. Boyer In 2023, La Niña conditions that generally prevailed in the eastern Pacific Ocean from mid-2020 into early 2023 gave way to a strong El Niño by October. Atmospheric concentrations of Earth’s major greenhouse gases—carbon dioxide, methane, and nitrous oxide—all increased to record-high levels. The annual global average carbon dioxide concentration in the atmosphere rose to 419.3±0.1 ppm, which is 50% greater than the pre-industrial level. The growth from 2022 to 2023 was 2.8 ppm, the fourth highest in the record since the 1960s. The combined short-term effects of El Niño and the long-term effects of increasing levels of heat-trapping gases in the atmosphere contributed to new records for many essential climate variables reported here. The annual global temperature across land and oceans was the highest in records dating as far back as 1850, with the last seven months (June–December) having each been record warm. Over land, the globally averaged temperature was also record high. Dozens of countries reported record or near-record warmth for the year, including China and continental Europe as a whole (warmest on record), India and Russia (second warmest), and Canada (third warmest). Intense and widespread heatwaves were reported around the world. In Vietnam, an all-time national maximum temperature record of 44.2°C was observed at Tuong Duong on 7 May, surpassing the previous record of 43.4°C at Huong Khe on 20 April 2019. In Brazil, the air temperature reached 44.8°C in Araçuaí in Minas Gerais on 20 November, potentially a new national record and 12.8°C above normal. The effect of rising temperatures was apparent in the cryosphere, where snow cover extent by June 2023 was the smallest in the 56-year record for North America and seventh smallest for the Northern Hemisphere overall. Heatwaves contributed to the greatest average mass balance loss for Alpine glaciers around the world since the start of the record in 1970. Due to rapid volume loss beginning in 2021, St. Anna Glacier in Switzerland and Ice Worm Glacier in the United States disappeared completely. In August, as a direct result of glacial thinning over the past 20 years, a glacial lake on a tributary of the Mendenhall Glacier in Alaska burst through its ice dam and caused unprecedented flooding on Mendenhall River near Juneau. Across the Arctic, the annual surface air temperature was the fourth highest in the 124-year record, and summer (July–September) was record warm. Smaller-than-normal snow cover extent in May and June contributed to the third-highest average peak tundra greenness in the 24-year record. In September, Arctic minimum sea ice extent was the fifth smallest in the 45-year satellite record. The 17 lowest September extents have all occurred in the last 17 years. In Antarctica, temperatures for much of the year were up to 6°C above average over the Weddell Sea and along coastal Dronning Maud Land. The Antarctic Peninsula also experienced well-above-average temperatures during the 2022/23 melt season, which contributed to its fourth consecutive summer of above-average surface melt. On 21 February, Antarctic sea ice extent and sea ice area both reached all-time lows, surpassing records set just a year earlier. Over the course of the year, new daily record-low sea ice extents were set on 278 days. In some instances, these daily records were set by a large margin, for example, the extent on 6 July was 1.8 million km2 lower than the previous record low for that day. Across the global oceans, the annual sea surface temperature was the highest in the 170-year record, far surpassing the previous record of 2016 by 0.13°C. Daily and monthly records were set from March onward, including an historic-high daily global mean sea surface temperature of 18.99°C recorded on 22 August. Approximately 94% of the ocean surface experienced at least one marine heatwave in 2023, while 27% experienced at least one cold spell. Globally averaged ocean heat content from the surface to 2000-m depth was record high in 2023, increasing at a rate equivalent to ∼0.7 Watts per square meter of energy applied over Earth’s surface. Global mean sea level was also record high for the 12th consecutive year, reaching 101.4 mm above the 1993 average when satellite measurements began, an increase of 8.1±1.5 mm over 2022 and the third highest year-over-year increase in the record. A total of 82 named tropical storms were observed during the Northern and Southern Hemispheres’ storm seasons, below the 1991–2020 average of 87. Hurricane Otis became the strongest landfalling hurricane on record for the west coast of Mexico at 140 kt (72 m s−1), causing at least 52 fatalities and $12–16 billion U.S. dollars in damage. Freddy became the world’s longest-lived tropical cyclones on record, developing into a tropical cyclone on 6 February and finally dissipating on 12 March. Freddy crossed the full width of the Indian Ocean and made one landfall in Madagascar and two in Mozambique. In the Mediterranean Sea—outside of traditional tropical cyclone basins—heavy rains and flooding from Storm Daniel killed more than 4300 people and left more than 8000 missing in Libya. The record-warm temperatures in 2023 created conditions that helped intensify the hydrological cycle. Measurements of total-column water vapor in the atmosphere were the highest on record, while the fraction of cloud area in the sky was the lowest since records began in 1980. The annual global mean precipitation total over land surfaces for 2023 was among the lowest since 1979, but global one-day maximum totals were close to average, indicating an increase in rainfall intensity. In July, record-high areas of land across the globe (7.9%) experienced extreme drought, breaking the previous record of 6.2% in July 2022. Overall, 29.7% of land experienced moderate or worse categories of drought during the year, also a record. Mexico reported its driest (and hottest) year since the start of its record in 1950. In alignment with hot and prolonged dry conditions, Canada experienced its worst national wildfire season on record. Approximately 15 million hectares burned across the country, which was more than double the previous record from 1989. Smoke from the fires were transported far into the United States and even to western European countries. August to October 2023 was the driest three-month period in Australia in the 104-year record. Millions of hectares of bushfires burned for weeks in the Northern Territory. In South America, extreme drought developed in the latter half of the year through the Amazon basin. By the end of October, the Rio Negro at Manaus, a major tributary of the Amazon River, fell to its lowest water level since records began in 1902. The transition from La Niña to El Niño helped bring relief to the prolonged drought conditions in equatorial eastern Africa. However, El Niño along with positive Indian Ocean dipole conditions also contributed to excessive rainfall that resulted in devastating floods over southeastern Ethiopia, Somalia, and Kenya during October to December that displaced around 1.5 million people. On 5 September, the town of Zagora, Greece, broke a national record for highest daily rainfall (754 mm in 21 hours, after which the station ceased reporting) due to Storm Daniel; this one-day accumulation was close to Zagora’s normal annual total.

BackgroundRemote sensing instruments enable high-throughput phenotyping of plant traits and stress resilience across scale. Spatial (handheld devices, towers, drones, airborne, and satellites) and temporal (continuous or intermittent) tradeoffs can enable or constrain plant science applications. Here, we describe the technical details of TSWIFT (Tower Spectrometer on Wheels for Investigating Frequent Timeseries), a mobile tower-based hyperspectral remote sensing system for continuous monitoring of spectral reflectance across visible-near infrared regions with the capacity to resolve solar-induced fluorescence (SIF).ResultsWe demonstrate potential applications for monitoring short-term (diurnal) and long-term (seasonal) variation of vegetation for high-throughput phenotyping applications. We deployed TSWIFT in a field experiment of 300 common bean genotypes in two treatments: control (irrigated) and drought (terminal drought). We evaluated the normalized difference vegetation index (NDVI), photochemical reflectance index (PRI), and SIF, as well as the coefficient of variation (CV) across the visible-near infrared spectral range (400 to 900 nm). NDVI tracked structural variation early in the growing season, following initial plant growth and development. PRI and SIF were more dynamic, exhibiting variation diurnally and seasonally, enabling quantification of genotypic variation in physiological response to drought conditions. Beyond vegetation indices, CV of hyperspectral reflectance showed the most variability across genotypes, treatment, and time in the visible and red-edge spectral regions.ConclusionsTSWIFT enables continuous and automated monitoring of hyperspectral reflectance for assessing variation in plant structure and function at high spatial and temporal resolutions for high-throughput phenotyping. Mobile, tower-based systems like this can provide short- and long-term datasets to assess genotypic and/or management responses to the environment, and ultimately enable the spectral prediction of resource-use efficiency, stress resilience, productivity and yield.

Proximal remote sensing offers a powerful tool for high-throughput phenotyping of plants for assessing stress response. Bean plants, an important legume for human consumption, are often grown in regions with limited rainfall and irrigation and are therefore bred to further enhance drought tolerance. We assessed physiological (stomatal conductance and predawn and midday leaf water potential) and ground- and tower-based hyperspectral remote sensing (400 to 2,400 nm and 400 to 900 nm, respectively) measurements to evaluate drought response in 12 common bean and 4 tepary bean genotypes across 3 field campaigns (1 predrought and 2 post-drought). Hyperspectral data in partial least squares regression models predicted these physiological traits (R 2 = 0.20 to 0.55; root mean square percent error 16% to 31%). Furthermore, ground-based partial least squares regression models successfully ranked genotypic drought responses similar to the physiologically based ranks. This study demonstrates applications of high-resolution hyperspectral remote sensing for predicting plant traits and phenotyping drought response across genotypes for vegetation monitoring and breeding population screening.

The extracellular RNA communication consortium (ERCC) is an NIH-funded program aiming to promote the development of new technologies, resources, and knowledge about exRNAs and their carriers. After Phase 1 (2013-2018), Phase 2 of the program (ERCC2, 2019-2023) aims to fill critical gaps in knowledge and technology to enable rigorous and reproducible methods for separation and characterization of both bulk populations of exRNA carriers and single EVs. ERCC2 investigators are also developing new bioinformatic pipelines to promote data integration through the exRNA atlas database. ERCC2 has established several Working Groups (Resource Sharing, Reagent Development, Data Analysis and Coordination, Technology Development, nomenclature, and Scientific Outreach) to promote collaboration between ERCC2 members and the broader scientific community. We expect that ERCC2's current and future achievements will significantly improve our understanding of exRNA biology and the development of accurate and efficient exRNA-based diagnostic, prognostic, and theranostic biomarker assays.

Monocytes are important regulators for the maintenance of homeostasis in innate and adaptive immune system and have been reported to play important role in cancer progression. CD47-SIRPα recognition is a coinhibitory immune signal to inhibit phagocytosis in monocytes and macrophages and has been well-known as the "Don't eat me" signal. By using an approach of integrated sensing and activating proteins (iSNAPs), we have rewired the CD47-SIRPα axis to create iSNAP-M which activates pathways in engineered human monocytes (iSNAP-MC). The mRNA expression levels of the monocyte/macrophage markers CD11b, CD14, and CD31 are upregulated in iSNAP-monocytes (iSNAP-MC). With PMA induction, the iSNAP-MC-derived macrophages (iSNAP-MΦ) showed upregelation in CD86 and CD80, but not CD206. TNFα expression and secretion were also increased in iSNAP-MΦ. Furthermore, the injection of iSNAP-MC into mice bearing human B-lymphoma tumors led to the suppression of tumor progression. Therefore, the engineered monocytes, via blockage of coinhibitory immune signals by rewiring CD47-SIRPα axis, can be applied to suppress target tumors for cancer immunotherapy.

Over the past few decades, neuroimaging has become a ubiquitous tool in basic research and clinical studies of the human brain. However, no reference standards currently exist to quantify individual differences in neuroimaging metrics over time, in contrast to growth charts for anthropometric traits such as height and weight1. Here we assemble an interactive open resource to benchmark brain morphology derived from any current or future sample of MRI data ( http://www.brainchart.io/ ). With the goal of basing these reference charts on the largest and most inclusive dataset available, acknowledging limitations due to known biases of MRI studies relative to the diversity of the global population, we aggregated 123,984 MRI scans, across more than 100 primary studies, from 101,457 human participants between 115 days post-conception to 100 years of age. MRI metrics were quantified by centile scores, relative to non-linear trajectories2 of brain structural changes, and rates of change, over the lifespan. Brain charts identified previously unreported neurodevelopmental milestones3, showed high stability of individuals across longitudinal assessments, and demonstrated robustness to technical and methodological differences between primary studies. Centile scores showed increased heritability compared with non-centiled MRI phenotypes, and provided a standardized measure of atypical brain structure that revealed patterns of neuroanatomical variation across neurological and psychiatric disorders. In summary, brain charts are an essential step towards robust quantification of individual variation benchmarked to normative trajectories in multiple, commonly used neuroimaging phenotypes.

Perovskite solar cells have drawn much attention recently owing to their world-record-setting photovoltaic performances, whereas their practicality is still limited by the structural instability that often arises from ion migration and defect formation. Despite the general understanding that ion instability is a primary cause for degradation, there is no observation of structural transformation at the atomistic scale. Such observation is crucial to understand how instabilities are induced by external perturbations such as illumination or electrical bias, allowing researchers to devise effective strategies to mitigate them. Here, we designed an in situ transmission electron microscopy setup to enable real-time observation of amorphization in perovskite materials under electrical biasing. To reverse the device performance degradation due to such structural changes, the samples were heated at 50 °C and were found to recrystallize, effectively regaining their performance losses. This work presents vital insights on understanding ion-migration phenomena and addressing instability challenges of perovskite optoelectronics.

We present a new measurement of the gas-phase mass-metallicity relation (MZR) and its dependence on star formation rates (SFRs) at 1.3 < z < 2.3. Our sample comprises 1056 galaxies with a mean redshift of z = 1.9, identified from the Hubble Space Telescope Wide Field Camera 3 (WFC3) grism spectroscopy in the Cosmic Assembly Near-infrared Deep Extragalactic Survey and the WFC3 Infrared Spectroscopic Parallel Survey. This sample is four times larger than previous metallicity surveys at z ~ 2 and reaches an order of magnitude lower in stellar mass (108 M o?). Using stacked spectra, we find that the MZR evolves by 0.3 dex relative to z ~ 0.1. Additionally, we identify a subset of 49 galaxies with high signal-to-noise (S/N) spectra and redshifts between 1.3 < z < 1.5, where Ha emission is observed along with [O iii] and [O ii]. With accurate measurements of SFR in these objects, we confirm the existence of a mass-metallicity-SFR (M-Z-SFR) relation at high redshifts. These galaxies show systematic differences from the local M-Z-SFR relation, which vary depending on the adopted measurement of the local relation. However, it remains difficult to ascertain whether these differences could be due to redshift evolution, as the local M-Z-SFR relation is poorly constrained at the masses and SFRs of our sample. Lastly, we reproduced our sample selection in the IllustrisTNG hydrodynamical simulation, demonstrating that our line flux limit lowers the normalization of the simulated MZR by 0.2 dex. We show that the M-Z-SFR relation in IllustrisTNG has an SFR dependence that is too steep by a factor of around 3.

In cryogenic fracturing, a rock surface exposed to cryogenic fluids undergoes a large thermal gradient, and the resultant local tensile stress overcomes rock strength and initiates fractures. This study investigates the development of cracks generated from the cryogenic treatment of a borehole under no external confining stress on specimens. The experiments were performed on transparent PMMA specimens to observe fracture proliferation around boreholes. Liquid nitrogen was flowed through the boreholes to cool the borehole surface. The results show that initial fracture growth is characterized by abrupt starts and stops, and as the fracture propagates outward, the growth appears more continuous. In an early stage, horizontal/radial fractures and vertical fractures are the defining patterns. Horizontal fractures tend to be separated by a specific exclusion distance (i.e., spacing between cracks). While distinct horizontal/vertical fractures and exclusion distance manifest themselves at an early stage, fractures resulting from fracture interactions and curvatures can develop into complex shapes at later stages. Cryogenic thermal loading induces distinctively curved fractures. The tendency of curvature may prevent greater penetration. An increase in the borehole pressure during liquid nitrogen flow, however, can lessen fracture tortu-osity and facilitate radial propagation. A high flow pressure and rate are also advantageous in that they accelerate cooling and fracture propagation.

Hydroxide-exchange-membrane water electrolysis (HEMWE) is an emerging hydrogen-production pathway that combines many advantages of incumbent alkaline water electrolysis (AWE) and proton-exchange-membrane water electrolysis (PEMWE). Advancement in HEMWE has been accelerated with the development of stable and conductive hydroxide exchange membranes (HEMs) and a more comprehensive understanding of alkaline gas-evolving kinetics. However, performance and durability without supporting electrolytes (SELs) remain inferior to PEMWE and AWE and little is known about the role and impact of the SELs. This study investigates the effects of SELs used as anolyte solutions in HEMWEs including cation-type, anion-type, SEL conductivity and pH, presence of carbonates and increased cation/OH- ratios on cell voltage and stability. We report our findings that (i) cell potential and high-frequency resistance did not correlate with anolyte SEL conductivity, (ii) cation-type influences cell voltage at low current densities (

Lithium metal has been an attractive candidate as a next-generation anode material. Despite its popularity, stability issues of lithium in the liquid electrolyte and the formation of lithium whiskers have kept it from practical use. Three-dimensional (3D) current collectors have been proposed as an effective method to mitigate whisker growth. Although extensive research has been done, the effects of three key parameters of the 3D current collectors, namely, the surface area, the tortuosity factor, and the surface chemistry, on the performance of lithium metal batteries remain elusive. Herein, we quantitatively studied the role of these three parameters by synthesizing four types of porous copper networks with different sizes of well-structured microchannels. X-ray microscale computed tomography (micro-CT) allowed us to assess the surface area, the pore size, and the tortuosity factor of the porous copper materials. A metallic Zn coating was also applied to study the influence of surface chemistry on the performance of the 3D current collectors. The effects of these parameters on the performance were studied in detail through scanning electron microscopy (SEM) and titration gas chromatography (TGC). Stochastic simulations further allowed us to interpret the role of the tortuosity factor in lithiation. The optimal range of the key parameters is thereby found for the porous coppers and their performance is predicted. Using these parameters to inform the design of porous copper anodes for Li deposition, Coulombic efficiencies (CEs) of up to 99.63% are achieved, thus paving the way for the design of effective 3D current collector systems.

Perovskite SrTiO3 (STO) is an attractive photocatalyst for solar watersplitting, but suffers from a limited photoresponse in the ultraviolet spectralrange due to its wide band gap. By means of hybrid density functional theorycalculations, we systematically study engineering its band gap via doping 4dand 5d transition metals M (M=Zr, Nb, Mo, Tc, Ru, Rh, Pd, Hf, Ta, W, Re, Os, Irand Pt) and chalcogen elements Y (Y=S and Se). We find that transition metaldopant M either has no effect on STO band gap or introduces detrimental mid-gapstates, except for Pd and Pt that are able to reduce the STO band gap. Incontrast, doping S and Se significantly reduces STO's direct band gap, thusleading to appreciable optical absorption transitions in the visible spectralrange. Our findings provide that Pd, S and Se doped STO are potential promisingphotocatalysts for water splitting under visible light irradiation, therebyproviding insightful theoretical guides for experiments to improve thephotocatalytic activity of STO.

The non-trivial topology of magnetic structures such as vortices and skyrmions is considered as a key concept to explain the stability of those structures. The stability, dictated by non-trivial topology, provides great potential for device applications. Although it is a very critical scientific and technological issue, it is elusive to experimentally study the topology-dependent stability owing to the difficulties in establishing stably formed magnetic structures with different topologies. Here, we establish a platform for vortex-antivortex structures with different topological charges within Ni80Fe20 rectangular elements thick enough to stabilize a unique three-dimensional magnetic structure with non-uniform magnetization along the thickness of the elements. The detailed magnetization configurations of the three-dimensional vortex-antivortex structures and their annihilations during their field-driven motions are investigated by utilizing magnetic transmission soft x-ray microscopy and micromagnetic simulation. We demonstrate that the stability of vortex-antivortex structures significantly depends on their topologies and the topology-dependent stability is associated with their different annihilation mechanisms. We believe that this work provides in-depth insight into the stability of magnetic structures and its topology dependence.

Many solid-state devices, especially those requiring anion conduction, often add a supporting electrolyte to enable efficient operation. The prototypical case is that of anion-exchange-membrane water electrolyzers (AEMWEs), where addition of an alkali metal solution improves performance. However, the specific mechanism of this performance improvement is currently unknown. This work investigates the functionality of the alkali metal solution in AEMWEs using experiments and mathematical models. The results show that additional hydroxide plays a key role not only in ohmic resistance of the membrane and catalyst layer but also in the reaction kinetics. The modeling suggests that the added liquid electrolyte creates an additional electrochemical interface with the electrocatalyst that provides ion-transport pathways and distributes product gas bubbles; the total effective electrochemical active surface area in the cell with 1 M KOH is 5 times higher than that of the cell with DI water. In the cell with 1 M KOH, more than 80% of the reaction current is associate with the liquid electrolyte. These results indicate the importance of high pH of electrolyte and catalyst/electrolyte interface in AEMWEs. The understanding of the functionality of the alkali metal solution presented in this study should help guide the design and optimization of AEMWEs.

Interest in alkali-rich oxide cathodes has grown in an effort to identify systems that provide high energy densities through reversible oxygen redox. However, some of the most promising compositions such as those based solely on earth abundant elements, e. g., iron and manganese, suffer from poor capacity retention and large hysteresis. Here, we use the disordered rocksalt cathode, Li1.3Fe0.4Nb0.3O2, as a model system to identify the underlying origin for the poor performance of Li-rich iron-based cathodes. Using elementally specific spectroscopic probes, we find the first charge is primarily accounted for by iron oxidation to 4+ below 4.25 V and O2 gas release beyond 4.25 V with no evidence of bulk oxygen redox. Although the Li1.3Fe0.4Nb0.3O2 is not a viable oxygen redox cathode, the iron 3+/4+ redox couple can be used reversibly during cycling.

A general approach for heritably altering gene expression has the potential to enable many discovery and therapeutic efforts. Here, we present CRISPRoff-a programmable epigenetic memory writer consisting of a single dead Cas9 fusion protein that establishes DNA methylation and repressive histone modifications. Transient CRISPRoff expression initiates highly specific DNA methylation and gene repression that is maintained through cell division and differentiation of stem cells to neurons. Pairing CRISPRoff with genome-wide screens and analysis of chromatin marks establishes rules for heritable gene silencing. We identify single guide RNAs (sgRNAs) capable of silencing the large majority of genes including those lacking canonical CpG islands (CGIs) and reveal a wide targeting window extending beyond annotated CGIs. The broad ability of CRISPRoff to initiate heritable gene silencing even outside of CGIs expands the canonical model of methylation-based silencing and enables diverse applications including genome-wide screens, multiplexed cell engineering, enhancer silencing, and mechanistic exploration of epigenetic inheritance.

Lithium-rich NMC (LR-NMC) compounds exhibit high capacities beyond the traditional redox, but it remains unclear whether the anomalous charge compensation mechanism is due to oxidized lattice oxygen or migration-assisted Mn oxidation. We compare LR-NMC with a model Mn7+ system (KMnO4) using a combination of resonant inelastic X-ray scattering (RIXS) irradiation studies and operando X-ray absorption spectroscopy/X-ray diffraction (XAS/XRD) to quantify transition metal (TM) migration, Mn oxidization, and beam-induced effects. We reveal how for KMnO4 it is possible to observe beam-induced Mn reduction resulting in trapped molecular oxygen. For LR-NMC, we observe negligible evidence for Mn oxidation while stabilized tetrahedral sites correlate more with a reduced TM environment. Finally, the additional spectroscopic structures observed in oxidized oxygen RIXS for LR-NMC are absent for gas-phase molecular oxygen.

This paper presents a study on the dynamics of a thin liquid film flowing down a vertical cylindrical fibre under a streamwise thermal gradient. Previous works on isothermal flows have shown that the inlet flow and fibre geometry are the main factors that determine a transition from the absolute to the convective instability flow regimes. Our experiments demonstrate that an irregular wavy pattern and bead coalescence, which are commonly seen in the convective regime, can also be triggered by applying a thermal gradient along the fibre. We develop a lubrication model that accounts for gravity, temperature-dependent viscosity and surface tension to describe the thermal effects on downstream bead dynamics. Numerical simulations of the model show good agreement between the predicted droplet coalescence dynamics and the experimental data.

For the sake of water and energy conservation, development of latent heat cooling and thermal storage systems that minimize water consumption and operate with higher efficacy than their water-driven counterparts is a crucial task. Phase change materials (PCMs) present a potential solution, but their integration into real-world systems abounds with scientific challenges such as material toxicity, flammability, low thermal performance and lack of tunable phase-change temperatures. In this study we report on a first-in-class nanocomposite PCM that leverages non-flammable, non-toxic, high latent heat sugar alcohols (SAs) encapsulated within easy-to-synthesize zeolitic imidazolate framework (ZIF) crystals. We also outline a practical route for surface functionalization with hydrophilic and hydrophobic moieties. The SA@ZIF composites display suppressed phase-change temperatures which, together with alterable surface functionality, broadens their applicability to a plethora of working environments. Direct synthesis of the SA@ZIF composite generates nanoconfined SAs with phase-change temperatures as low as 19.8 °C and latent heats as high as 285 J g-1. This nanoconfinement-induced thermal phenomenon is conserved even after functionalization of the SA@ZIF crystal surface. We believe this study will lay the groundwork as a platform for next generation high performing, tunable PCMs to aid in the realization of waterless cooling systems.

A photometric redshift sample of luminous red galaxies (LRGs) obtained from the DECam Legacy Survey (DECaLS) is analyzed to probe cosmic distances by exploiting the wedge approach of the two-point correlation function. Although the cosmological information is highly contaminated by the uncertainties existing in the photometric redshifts from the galaxy map, an angular diameter distance can be probed at the perpendicular configuration in which the measured correlation function is minimally contaminated. An ensemble of wedged correlation functions selected up to a given threshold based on having the least contamination was studied in previous work (Sridhar & Song 2019) using simulations, and the extracted cosmological information was unbiased within this threshold. We apply the same methodology for analyzing the LRG sample from DECaLS, which will provide the optical imaging for targeting two-thirds of the Dark Energy Spectroscopic Instrument footprint and measure the angular diameter distances at z = 0.69 and z = 0.87 to be and with a fractional error of 4.77% and 6.09%, respectively. We obtain a value of H 0 = 66.58 ± 5.31 km s-1 Mpc-1, which supports the H 0 measured by all other baryon acoustic oscillation results and is consistent with the ΛCDM model.

Li metal anode coupled with solid-state electrolyte is regarded as an important step for next-generation high-energy batteries to boost the performance of electric vehicles. However, commercialization of Li metal anode in all-solid-state batteries have faced challenges, one of which is the interfacial instability originated during battery operation. To overcome the difficulties in characterizing such interfaces due to their sensitivity to beam and ambient air, we applied cryogenic electron microscopy to unravel the stable nature of Li metal/LiPON interface that has exhibited remarkable electrochemical cyclability. An 80-nm-thick interphase with concentration gradients of N and P was observed, with decomposition products embedded in an amorphous matrix and exhibiting a multilayer-mosaic structure. The findings and methodology in this work give rise to a mechanistic understanding of the stability of Li metal/LiPON interface and can then be extended to study other solid-solid interfaces.

The nematic phase in iron based superconductors (IBSs) has attracted attention with a notion that it may provide important clue to the superconductivity. A series of angle-resolved photoemission spectroscopy (ARPES) studies were performed to understand the origin of the nematic phase. However, there is lack of ARPES study on LaFeAsO nematic phase. Here, we report the results of ARPES studies of the nematic phase in LaFeAsO. Degeneracy breaking between the [Formula: see text] and [Formula: see text] hole bands near the [Formula: see text] and M point is observed in the nematic phase. Different temperature dependent band splitting behaviors are observed at the [Formula: see text] and M points. The energy of the band splitting near the M point decreases as the temperature decreases while it has little temperature dependence near the [Formula: see text] point. The nematic nature of the band shift near the M point is confirmed through a detwin experiment using a piezo device. Since a momentum dependent splitting behavior has been observed in other iron based superconductors, our observation confirms that the behavior is a universal one among iron based superconductors.

The nematic phase in iron based superconductors (IBSs) has attracted attention with a notion that it may provide important clue to the superconductivity. A series of angle-resolved photoemission spectroscopy (ARPES) studies were performed to understand the origin of the nematic phase. However, there is lack of ARPES study on LaFeAsO nematic phase. Here, we report the results of ARPES studies of the nematic phase in LaFeAsO. Degeneracy breaking between the [Formula: see text] and [Formula: see text] hole bands near the [Formula: see text] and M point is observed in the nematic phase. Different temperature dependent band splitting behaviors are observed at the [Formula: see text] and M points. The energy of the band splitting near the M point decreases as the temperature decreases while it has little temperature dependence near the [Formula: see text] point. The nematic nature of the band shift near the M point is confirmed through a detwin experiment using a piezo device. Since a momentum dependent splitting behavior has been observed in other iron based superconductors, our observation confirms that the behavior is a universal one among iron based superconductors.

We study the effects of nozzle geometry on the dynamics of thin fluid films flowing down a vertical cylindrical fibre. Recent experiments show that varying the nozzle diameter can lead to different flow regimes and droplet characteristics in the film. Using a weighted residual modelling approach, we develop a system of coupled equations that account for inertia, surface tension effects, gravity and a film stabilization mechanism to describe both near-nozzle fluid structures and downstream bead dynamics. We report good agreement between the predicted droplet properties and the experimental data.

The rapidly growing technological demand for lithium-ion batteries has prompted the development of novel cathode materials with high energy density, low cost, and improved safety. High voltage spinel, LiNi0.5Mn1.5O4 (LNMO), is one of the most promising candidates yet to be commercialized. The two primary obstacles for this material are the inferior electronic conductivity and fast capacity degradation in full cells due to the high operating voltage. By systematically addressing these limitations, we successfully develop a thick LNMO electrode with areal capacity loadings up to 3 mAh·cm−2. The optimized thick electrode is paired with a commercial graphite anode at both the coin cell and pouch cell level, achieving a full cell capacity retention as high as 72% and 78%, respectively, after 300 cycles. We attribute this superior cycling stability to careful optimizations of cell components and testing conditions, with a specific focus improving electronic conductivity and high voltage compatibility. These results suggest precise control of materials quality, electrode architecture and electrolyte optimization can soon support the development of a cobalt-free battery system based on a thick LNMO cathode (>4 mAh·cm2), which will eventually meet the needs of next-generation Li-ion batteries with reduced cost, improved safety, and assured sustainability.

Lithium-sulfur (Li–S) battery is one of the most promising candidates for the next generation energy storage systems. However, several barriers, including polysulfide shuttle effect, the slow solid-solid surface reaction pathway in the lower discharge plateau, and corrosion of Li anode still limit its practical applications, especially under the lean electrolyte condition required for high energy density. Here, we propose a solution-mediated sulfur reduction pathway to improve the capacity and reversibility of the sulfur cathode. With this method, a high coulombic efficiency (99%) and stable cycle life over 100 cycles were achieved under application-relevant conditions (S loading: 6.2 mg cm−2; electrolyte to sulfur ratio: 3 mLE gs−1; sulfur weight ratio: 72 wt%). This result is enabled by a specially designed Li2S4-rich electrolyte, in which Li2S is formed through a chemical disproportionation reaction instead of electrochemical routes. A single diglyme solvent was used to obtain electrolytes with the optimum range of Li2S4 concentration. Operando X-ray absorption spectroscopy confirms the solution pathway in a practical Li–S cell. This solution pathway not only introduces a new electrolyte regime for practical Li–S batteries, but also provides a new perspective for bypassing the inefficient surface pathway for other electrochemical processes.

Sodium borohydride (NaBH4) has been a material of interest for many years in developing metal boride complexes and shows a great deal of potential as a hydrogen storage material. Though many have used various additives as catalysts to weaken the bonds within NaBH4 to create a more energetically favorable material, very little is understood about how the borohydride interacts with and changes the additives being incorporated. This work uses ball milling to incorporate calcium chloride (CaCl2) into NaBH4. Using several x-ray techniques, thermogravimetric analysis, and Raman spectroscopy, this study shows not only that the salt diffuses into NaBH4 but describes how the borohydride changes the additive itself. In gaining a stronger understanding of what happens to the additives needed to weaken the borohydride bonds, future researchers may have an easier time selecting the appropriate additive to create a borohydride complex that will meet their needs.

An energy storage paradigm orthogonal to Li-ion battery chemistries can be conceptualized by employing anions as the primary charge carriers. F-ion conversion chemistries show promise but have limited cyclability as a result of the significant change in volume of active electrodes upon metal-metal fluoride interconversion. In contrast, the exploration of insertion chemistries has been stymied by the lack of hosts amenable to reversible F-ion insertion at room temperature. Here we show the reversible and homogeneous topochemical insertion/deinsertion and bulk diffusion of F ions within the one-dimensional tunnels of submicrometer-sized FeSb2O4 particles at room temperature. The insertion of F ions is evidenced by formal oxidation of the iron centers from Fe2+ to Fe3+ with a lattice volume contraction of

The use of oxide cathodes in Mg batteries would unlock a potential energy storage system that delivers high-energy density. However, poor kinetics of Mg diffusion in known solid oxide lattices strongly limits reversible intercalation, which motivates the sustained exploration of new candidates. Herein, nanocrystals of a few-layer phyllomanganate, reminiscent of the mineral vernadite, were shown to have considerable electrochemical activity toward Mg intercalation at room temperature, where it delivered ∼190 mAh g-1 at ∼1.9 V (vs Mg/Mg2+) in batteries paired with a Mg metal anode. Multimodal characterization confirmed the notable degree of reversible intercalation by probing the structural, compositional, and redox changes undertaken by the oxide. Distinct levels of Mg activity were also observed while varying the content of small amounts of lattice water and the temperature of the reaction. The results reaffirm the prospects for operational Mg batteries using oxide cathodes in moderate conditions, overcoming current limits of performance of this prospective technology.

The solvation shell structures of Ca2+ in aqueous and organic solutions probed by calcium L-edge soft X-ray absorption spectroscopy (XAS) and DFT/MD simulations show the coordination number of Ca2+ to be negatively correlated with the electrolyte concentration and the steric hindrance of the solvent molecule. In this work, the calcium L-edge soft XAS demonstrates its sensitivity to the surrounding chemical environment. Additionally, the total electron yield (TEY) mode is surface sensitive because the electron penetration depth is limited to a few nanometers. Thus this study shows its implications for future battery studies, especially for probing the electrolyte/electrode interface for electrochemical reactions under in situ/operando conditions.

This paper documents the 16th data release (DR16) from the Sloan Digital Sky Surveys (SDSS), the fourth and penultimate from the fourth phase (SDSS-IV). This is the first release of data from the Southern Hemisphere survey of the Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2); new data from APOGEE-2 North are also included. DR16 is also notable as the final data release for the main cosmological program of the Extended Baryon Oscillation Spectroscopic Survey (eBOSS), and all raw and reduced spectra from that project are released here. DR16 also includes all the data from the Time Domain Spectroscopic Survey and new data from the SPectroscopic IDentification of ERosita Survey programs, both of which were co-observed on eBOSS plates. DR16 has no new data from the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey (or the MaNGA Stellar Library "MaStar"). We also preview future SDSS-V operations (due to start in 2020), and summarize plans for the final SDSS-IV data release (DR17).

In cold pulse experiments in J-TEXT, the ion transport shows similar non-local response as the electron transport channel. Very fast ion temperature decreases are observed in the edge, while the ion temperature in the core promptly begin to rise after the injection of cold pulse. Moreover, the cutoff density is also found for the ion non-local effect. The experimental observed density fluctuation in a high frequency ranging from 500 kHz to 2 MHz is obviously reduced in the whole plasma region during non-local transport phase.

Na metal is an attractive anode material for rechargeable Na ion batteries, however, the dendritic growth of Na can cause serious safety issues. Along with modifications of solid-electrolyte interphase (SEI), engineering the electrode has been reported to be effective in suppressing Na dendritic growth, likely by reducing localized current density accumulation. However, fundamental understanding of Na growth at the nanoscale is still limited. Here, we report an in-situ study of Na electrodeposition in electrochemical liquid cells with the electrodes in different surface roughness, e.g., flat or sharp curvature. Real time observation using transmission electron microscopy (TEM) reveals the Na electrodeposition with remarkable details. Relatively large Na grains (in the micrometer scale) are achieved on the flat electrode surface. The local SEI thickness variations impact the growth rate, thus the morphology of individual grains. In contrast, small Na grains (in tens of nanometers) grow explosively on the electrode at the point with sharp curvature. The newly formed Na grains preferentially deposit at the base of existing grains close to the electrode. Further studies using continuum-based computational modeling suggest that the growth mode of an alkali metal (e.g. Na) is strongly influenced by the transport properties of SEI. Our direct observation of Na deposition in combination with the theoretical modeling provides insights for comprehensive understanding of electrode roughness and SEI effects on Na electrochemical deposition.

The capabilities of soft x-ray absorption (XAS), soft x-ray emission spectroscopy (XES), resonant inelastic soft x-ray scattering (RIXS), and their application to characterization of solar energy materials are presented. We have discussed some recent developments of in-situ soft x-ray spectroscopy cells, which enable the investigation of critical solid/liquid or solid/gas interfaces in chemical and electrochemical processes under real-world practical conditions. In particular, in-situ soft x-ray spectroscopies can be utilized to probe the formation of intermediate species, charge separation upon illumination of sunlight and electron transfer to the interfacial reactions. A number of examples using soft x-ray spectroscopies to study these solar energy and catalytic materials are discussed to demonstrate how these powerful characterization tools could be helpful to further understand the energy conversion and energy storage systems.

Gonorrhea remains a major public health challenge, and current recommendations for gonorrhea treatment are threatened by evolving antimicrobial resistance and a diminished pipeline for new antibiotics. Evaluations of potential new treatments for gonorrhea currently make limited use of new understanding of the pharmacokinetic and pharmacodynamic contributors to effective therapy, the prevention of antimicrobial resistance, and newer designs for clinical trials. They are hampered by the requirement to utilize combination ceftriaxone/azithromycin therapy as the comparator regimen in noninferiority trials designed to seek an indication for gonorrhea therapy. Evolving gonococcal epidemiology and clinical trial design constraints hinder the enrollment of those populations at the greatest risk for gonorrhea (adolescents, women, and persons infected with antibiotic-resistant Neisseria gonorrhoeae). This article summarizes a recent meeting on the evaluation process for antimicrobials for urogenital gonorrhea treatment and encourages the consideration of new designs for the evaluation of gonorrhea therapy.

To achieve high-energy all-solid-state batteries (ASSBs), solid-state electrolytes (SE) must be thin, mechanically robust, and possess the ability to form low resistance interfaces with electrode materials. Embedding an inorganic SE into an organic polymer combines the merits of high conductivity and flexibility. However, the performance of such an SE-in-polymer matrix (SEPM) is highly dependent on the microstructure and interactions between the organic and inorganic components. We report on the synthesis of a free-standing, ultrathin (60 μm) SEPM from a solution of lithium polysulfide, phosphorus sulfide, and ethylene sulfide (ES), where the polysulfide triggers the in situ polymerization of ES and the formation of Li3PS4. Reactant ratios were optimized to achieve a room-temperature conductivity of 2 × 10-5 S cm-1. Cryogenic electron microscopy confirmed a uniform nanoscopic distribution of β-Li3PS4 and PES (polyethylene sulfide). This work presents a facile route to the scalable fabrication of ASSBs with promising cycling performance and low electrolyte loading.

Conventional electrolytes made by mixing simple Mg2+ salts and aprotic solvents, analogous to those in Li-ion batteries, are incompatible with Mg anodes because Mg metal readily reacts with such electrolytes, producing a passivation layer that blocks Mg2+ transport. Here, we report that, through tuning a conventional electrolyte - Mg(TFSI)2 (TFSI- is N(SO2CF3)2-) - with an Mg(BH4)2 cosalt, highly reversible Mg plating/stripping with a high Coulombic efficiency is achieved by neutralizing the first solvation shell of Mg cationic clusters between Mg2+ and TFSI- and enhanced reductive stability of free TFSI-. A critical adsorption step between Mg0 atoms and active Mg cation clusters involving BH4- anions is identified to be the key enabler for reversible Mg plating/stripping through analysis of the distribution of relaxation times (DRT) from operando electrochemical impedance spectroscopy (EIS), operando electrochemical X-ray absorption spectroscopy (XAS), nuclear magnetic resonance (NMR), and density functional theory (DFT) calculations.

We study the effects of nozzle geometry on the dynamics of thin fluid films flowing down a vertical cylindrical fibre. Recent experiments show that varying the nozzle diameter can lead to different flow regimes and droplet characteristics in the film. Using a weighted residual modelling approach, we develop a system of coupled equations that account for inertia, surface tension effects, gravity and a film stabilization mechanism to describe both near-nozzle fluid structures and downstream bead dynamics. We report good agreement between the predicted droplet properties and the experimental data.

Stable lattice oxygen redox (l-OR) is the key enabler for achieving attainable high energy density in Li-rich layered oxide cathode materials for Li-ion batteries. However, the unique local structure response to oxygen redox in these materials, resulting in energy inefficiency and hysteresis, still remains elusive, preventing their potential applications. By combining the state-of-the-art neutron pair distribution function with crystal orbital overlap analysis, we directly observe the distinct local structure adaption originated from the potential O–O chemical bonds. The structure adaptability is optimized based on the nature of multi transition metals in our model compound Li1.2Ni0.13Mn0.54Co0.13O2, which accommodates the oxygen redox and at the same time preserves the global layered structure. These findings not only advance the understanding of l-OR, but also provide new perspectives in the rational design of high-energy-density cathode materials with reversible and stable l-OR.

We have investigated the initial-cycle battery behavior of epitaxial thin films of Li2MnO3 cathodes by employing resonant inelastic X-ray scattering (RIXS) at the O K-edge and Mn L3-edge. Thin films (25 nm thickness) with Li/Mn ratios of 2.06 (stoichiometric) and 2.27 (overstoichiometric) were epitaxially grown by pulsed laser deposition and electrochemically cycled as battery cathodes in a half-cell setup, stopped at potentials for full charge (delithiation) and complete discharge (relithiation) for X-ray analysis. No signatures of localized oxygen holes are found in O K-RIXS of the Li2MnO3 regardless of the Li/Mn ratio. The prepeak region of the O K-XAS shows a net increase (a net decrease) after delithiation (relithiation) for both material compositions. Moreover, signatures of additional phases are detected only for the overstoichiometric material upon relithiation. Mn L-RIXS of the overstoichiometric cathode material shows a progressive loss of charge transfer state intensity during the first battery cycle, revealing a more rapid loss of Mn-O covalency in the overstoichiometric material.

This study investigates the evolution of superconductivity in K2-xFe4+ySe5 using temperature-dependent X-ray absorption and resonant inelastic X-ray scattering techniques. Magnetization measurements show that polycrystalline superconducting (SC) K1.9Fe4.2Se5 has a critical temperature (T c) of ∼31 K with a varying superconducting volume fraction, which strongly depends on its synthesis temperature. An increase in Fe-structural/vacancy disorder in SC samples with more Fe atoms occupying vacant 4d sites is found to be closely related to the decrease in the spin magnetic moment of Fe. Moreover, the nearest-neighbor Fe-Se bond length in SC samples exceeds that in the non-SC (NS) sample, K2Fe4Se5, which indicates a weaker hybridization between the Fe 3d and Se 4p states in SC samples. These results clearly demonstrate the correlations among the local electronic and atomic structures and the magnetic properties of K2-xFe4+ySe5 superconductors, providing deeper insight into the electron pairing mechanisms of superconductivity.

This study investigates the evolution of superconductivity in K2-xFe4+ySe5 using temperature-dependent X-ray absorption and resonant inelastic X-ray scattering techniques. Magnetization measurements show that polycrystalline superconducting (SC) K1.9Fe4.2Se5 has a critical temperature (T c) of ∼31 K with a varying superconducting volume fraction, which strongly depends on its synthesis temperature. An increase in Fe-structural/vacancy disorder in SC samples with more Fe atoms occupying vacant 4d sites is found to be closely related to the decrease in the spin magnetic moment of Fe. Moreover, the nearest-neighbor Fe-Se bond length in SC samples exceeds that in the non-SC (NS) sample, K2Fe4Se5, which indicates a weaker hybridization between the Fe 3d and Se 4p states in SC samples. These results clearly demonstrate the correlations among the local electronic and atomic structures and the magnetic properties of K2-xFe4+ySe5 superconductors, providing deeper insight into the electron pairing mechanisms of superconductivity.

Photon strength functions describing the average response of the nucleus to an electromagnetic probe are key input information in the theoretical modelling of nuclear reactions. Consequently they are important for a wide range of fields such as nuclear structure, nuclear astrophysics, medical isotope production, fission and fusion reactor technologies. They are also sources of information for widely used reaction libraries such as the IAEA Reference Input Parameter Library and evaluated data files such as EGAF. In the past two decades, the amount of reaction gamma-ray data measured to determine photon strength functions has grown rapidly. Different experimental techniques have led to discrepant results and users are faced with the dilemma of which (if any) of the divergent data to adopt. We report on a coordinated effort to compile and assess the existing experimental data on photon strength functions from the giant dipole resonance region to energies below the neutron separation energy. The assessment of the discrepant data at energies around or below the neutron separation energy has been possible only in a few cases where adequate information on the model-dependent analysis and estimation of uncertainties was available. In the giant dipole resonance region, we adopt the recommendations of the new IAEA photonuclear data library. We also present global empirical and semi-microscopic models that describe the photon strength functions in the entire energy region and reproduce reasonably well most of the experimental data. The compiled experimental photon strengths and recommended model calculations are available from the PSF database hosted at the IAEA (http://www-nds.iaea.org/PSFdatabase).

Photon strength functions describing the average response of the nucleus to an electromagnetic probe are key input information in the theoretical modelling of nuclear reactions. Consequently they are important for a wide range of fields such as nuclear structure, nuclear astrophysics, medical isotope production, fission and fusion reactor technologies. They are also sources of information for widely used reaction libraries such as the IAEA Reference Input Parameter Library and evaluated data files such as EGAF. In the past two decades, the amount of reaction gamma-ray data measured to determine photon strength functions has grown rapidly. Different experimental techniques have led to discrepant results and users are faced with the dilemma of which (if any) of the divergent data to adopt. We report on a coordinated effort to compile and assess the existing experimental data on photon strength functions from the giant dipole resonance region to energies below the neutron separation energy. The assessment of the discrepant data at energies around or below the neutron separation energy has been possible only in a few cases where adequate information on the model-dependent analysis and estimation of uncertainties was available. In the giant dipole resonance region, we adopt the recommendations of the new IAEA photonuclear data library. We also present global empirical and semi-microscopic models that describe the photon strength functions in the entire energy region and reproduce reasonably well most of the experimental data. The compiled experimental photon strengths and recommended model calculations are available from the PSF database hosted at the IAEA (http://www-nds.iaea.org/PSFdatabase).

All solid-state batteries (ASSBs) have the potential to deliver higher energy densities, wider operating temperature range, and improved safety compared with today's liquid-electrolyte-based batteries. However, of the various solid-state electrolyte (SSE) classes - polymers, sulfides, or oxides - none alone can deliver the combined properties of ionic conductivity, mechanical, and chemical stability needed to address scalability and commercialization challenges. While promising strategies to overcome these include the use of polymer/oxide or sulfide composites, there is still a lack of fundamental understanding between different SSE-polymer-solvent systems and its selection criteria. Here, we isolate various SSE-polymer-solvent systems and study their molecular level interactions by combining various characterization tools. With these findings, we introduce a suitable Li7P3S11SSE-SEBS polymer-xylene solvent combination that significantly reduces SSE thickness (∼50 μm). The SSE-polymer composite displays high room temperature conductivity (0.7 mS cm-1) and good stability with lithium metal by plating and stripping over 2000 h at 1.1 mAh cm-2. This study suggests the importance of understanding fundamental SSE-polymer-solvent interactions and provides a design strategy for scalable production of ASSBs.