High-rate capable, reversible lithium metal anodes are necessary for next generation energy storage systems. In situ tomography of Li|LLZO|Li cells is carried out to track morphological transformations in Li metal electrodes. Machine learning enables tracking the lithium metal morphology during galvanostatic cycling. Nonuniform lithium electrode kinetics are observed at both electrodes during cycling. Hot spots in lithium metal are correlated with microstructural anisotropy in LLZO. Mesoscale modeling reveals that regions with lower effective properties (transport and mechanical) are nuclei for failure. Advanced visualization combined with electrochemistry represents an important pathway toward resolving non-equilibrium effects that limit rate capabilities of solid-state batteries.

Mollisols support the most productive agroecosystems in the world. Despite their critical links to food quality and human health, the varying distributions of selenium (Se) species and factors governing Se mobility in the mollisol vadose zone remain elusive. This research reveals that, in northern mollisol agroecosystems, Se hotspots (≥0.32 mg/kg) prevail along the regional river systems draining the Lesser Khingan Mountains, where piedmont Se-rich oil shales are the most probable source of regional Se. While selenate and selenite dominate Se species in the water-soluble and absorbed pools, mollisol organic matter is the major host for Se. Poorly crystalline and crystalline Fe oxides are subordinate in Se retention, hosting inorganic and organic Se at levels comparable to those in the adsorbed pool. The depth-dependent distributions of mollisol Se species for the non-cropland and cropland sites imply a predominance of reduced forms of Se under the mildly acidic and reducing conditions that, in turn, are variably impacted by agricultural land use. These findings therefore highlight that fluvial deposition and land use change together are the main drivers of the spatial variability and speciation of mollisol Se.

Due to their high reaction rate and reliable selectivity, bioorthogonal click reactions have been extensively investigated in numerous research fields, such as nanotechnology, drug delivery, molecular imaging, and targeted therapy. Previous reviews on bioorthogonal click chemistry for radiochemistry mainly focus on 18F-labeling protocols employed to produce radiotracers and radiopharmaceuticals. In fact, besides fluorine-18, other radionuclides such as gallium-68, iodine-125, and technetium-99m are also used in the field of bioorthogonal click chemistry. Herein, to provide a more comprehensive perspective, we provide a summary of recent advances in radiotracers prepared using bioorthogonal click reactions, including small molecules, peptides, proteins, antibodies, and nucleic acids as well as nanoparticles based on these radionuclides. The combination of pretargeting with imaging modalities or nanoparticles, as well as the clinical translations study, are also discussed to illustrate the effects and potential of bioorthogonal click chemistry for radiopharmaceuticals.

In the current study, the characteristics of aerosol water-soluble ions (WSI) were investigated via high-time-resolution observations as part of the nineth Chinese National Arctic Research Expedition (CHINARE) in 2018. WSI, including Cl − , SO 4

Reversible lithium metal anodes that can achieve high rate capabilities are necessary for next generation energy storage systems. Solid electrolyte can act as a barrier for unwanted physical and chemical decomposition that lead to unstable electrodeposition (e.g. dendrite and filament growth). The formation and growth of filaments is tied to unique chemo-mechanical properties that exists at buried solid|solid interfaces. Herein,<i> in situ</i> tomography of Li|LLZO|Li cells is carried out to track morphological transformations in Li metal electrodes and buried solid|solid interfaces during stripping and plating processes. Optimized experimental parameters provide high resolution, high contrast reconstructions that enable lithium metal visualization. Machine learning and image processing tools are combined to quantify changes in lithium metal during stripping and plating. The analysis enables quantifying local current densities and pore size distribution in lithium metal during cycling experiments. Hotspots in lithium metal are correlated with microstructural anisotropy in the solid electrolyte. Modeling studies show large heterogeneity in transport and mechanical properties of electrolyte at the electrode|electrolyte interfaces. Regions with lower effective properties (transport and mechanical) are nuclei for failure. Failure is attributed to microstructural heterogeneities in the solid electrolyte that lead to high local stress and flux distributions.

No abstract

No abstract

Surface and core sediments were investigated in the lower Han River Basin, a tributary of Changjiang River in China to evaluate the nitrogen (N) pollution of sediments and N fluxes as well as their influencing factors at the sediment-water interface. Two methods of sediment pollution assessment were applied and the results showed that the sediment at site H9 was the most contaminated and that at site H4 and H7 was almost unpolluted. pH was significantly and positively correlated with total nitrogen (TN) content and NH + 4 flux (P < 0.05), indicating that N fluxes could be related to environmental factors. NO − 3 was generally from out of the sediment and into water, while NH + 4 diffused into sediment from water at some sites. Overall, the N fluxes were extremely high, revealing the considerable risk in internal N release. It is of great importance to strengthen the ecological restoration and control the internal N release.