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Nickel-based complex oxides have served as a playground for decades in the quest for a copper-oxide analog of the high-temperature superconductivity. They may provide clues towards understanding the mechanism and an alternative route for high-temperature superconductors. The recent discovery of superconductivity in the infinite-layer nickelate thin films has fulfilled this pursuit. However, material synthesis remains challenging, direct demonstration of perfect diamagnetism is still missing, and understanding of the role of the interface and bulk to the superconducting properties is still lacking. Here, we show high-quality Nd 0.8 Sr 0.2 NiO 2 thin films with different thicknesses and demonstrate the interface and strain effects on the electrical, magnetic and optical properties. Perfect diamagnetism is achieved, confirming the occurrence of superconductivity in the films. Unlike the thick films in which the normal-state Hall-coefficient changes signs as the temperature decreases, the Hall-coefficient of films thinner than 5.5 nm remains negative, suggesting a thickness-driven band structure modification. Moreover, X-ray absorption spectroscopy reveals the Ni-O hybridization nature in doped infinite-layer nickelates, and the hybridization is enhanced as the thickness decreases. Consistent with band structure calculations on the nickelate/SrTiO 3 heterostructure, the interface and strain effect induce a dominating electron-like band in the ultrathin film, thus causing the sign-change of the Hall-coefficient. Nickelate superconductors attract enormous attention in the field of high-temperature superconductivity. Here the authors report observation of perfect diamagnetism and interfacial effect on the electronic structures in infinite layer Nd 0.8 Sr 0.2 NiO 2 superconductors.

We report strong ferromagnetism of quasiparticle doped holes both within the ab- plane and along the c- axis of Cu-O planes in low-dimensional Au/ d- La 1.8 Ba 0.2 CuO 4 /LaAlO 3 (001) heterostructures ( d  = 4, 8 and 12 unit-cells) using resonant soft X-ray and magnetic scattering together with X-ray magnetic circular dichroism. Interestingly, ferromagnetism is stronger at a hole doped peak and at an upper Hubbard band of O with spin-polarization degree as high as 40%, revealing strong ferromagnetism of Mottness. For in- ab -plane spin-polarizations, the spin of doped holes in O2 p –Cu3 d –O2 p is a triplet state yielding strong ferromagnetism. For out-of- ab -plane spin-polarization, while the spins of doped holes in both O2 p –O2 p and Cu3 d –Cu3 d are triplet states, the spin of doped holes in Cu3 d –O2 p is a singlet state yielding ferrimagnetism. A ferromagnetic-(002) Bragg-peak of the doped holes is observed and enhanced as a function of d revealing strong ferromagnetism coupling between Cu-O layers along the c -axis. Long-range magnetic order of quasiparticle doped holes is important for understanding the physics of cuprate superconductors, albeit difficult to probe in experiments. Ong et al. observe ferromagnetism of quasiparticle doped holes in a cuprate heterostructure and discuss implications for cuprates in the ground state.

As the 3D laser scanning and photogrammetry technologies continue to mature, more and more applications founded in numerous areas. The realistic 3D models are mainly adopted for digital display uses, such as the 3D game, web showcases, head-mounted display, etc. While we are enjoying the vivid digital sceneries through different kinds of digital display screens, there are still challenges exist for the 3D printing application, especially for large size objects. In this article, we will present an approach on digitizing and 3D replicating large grottoes. Unlike 3D rendering, 3D printing requires high detailed shape data for the fabrication. Such demands cause many technical difficulties including huge data amount, accurate dense point cloud, high-resolution texture mapping. We chose cascade SfM, grouped MVS, automatic texture mapping to prepare the high definition colored 3D model for printing and painting references. Meanwhile, we optimized 3D printing procedure as well as post-processing, installation, lacquer and painting. Two replicas of 10- meter sized grottoes have been manufactured after four years of efforts, which have earned some appreciations from audiences.

Potassium niobate KNbO 3 powder was synthesized via a solid-state reaction method. X-ray diffraction analysis confirmed that the compound is orthorhombic structure with space group C m2   m . The cuboid-shape morphology with average grain size about 100–300 nm was observed by scanning electron microscope. A strong absorption from the onset at 350 nm was observed, and the energy bandgap is estimated to be 3.23 eV. KNbO 3 also exhibits an obvious photovoltaic response from 320 to 380 nm with a peak at 352 nm, which is due to the electronic transfer from O 2p to Nb 4d. It was suggested that the build-in electric field mainly contribute to the photovoltaic response for orthorhombic KNbO 3 .

The present study reports Bi 5 FeTi 3 O 15 (BFTO) nanofibers/graphene (Gr) nanocomposites (BGr) as counter electrodes (CEs) in dye-sensitized solar cells (DSSCs). BFTO nanofibers with diameters of 40–100 nm were fabricated by sol-gel based electrospinning technique. The microstructure and surface morphology of the BFTO nanofibers and the BGr nanocomposites were characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The electrochemical performances of BGr CEs were comprehensively characterized and investigated. Compared to pristine BFTO, the nanocomposites have a marked improvement in electrocatalytic performance for the reduction of triiodide because of larger surface area and lower transfer resistance on the electrolyte-electrode interface. The maximum power conversion efficiency has reached 9.56%, which is much larger than that of pure BFTO CEs (0.22%).

Anthropogenic aerosols (AAs) induce global and regional tropospheric circulation adjustments due to the radiative energy perturbations. The overall cooling effects of AA, which mask a portion of global warming, have been the subject of many studies but still have large uncertainty. The interhemispheric contrast in AA forcing has also been demonstrated to induce a major shift in atmospheric circulation. However, the zonal redistribution of AA emissions since start of the 20th century, with a notable decline in the Western Hemisphere (North America and Europe) and a continuous increase in the Eastern Hemisphere (South Asia and East Asia), has received less attention. Here we utilize four sets of single-model initial-condition large-ensemble simulations with various combinations of external forcings to quantify the radiative and circulation responses due to the spatial redistribution of AA forcing during 1980–2020. In particular, we focus on the distinct climate responses due to fossil-fuel-related (FF) aerosols emitted from the Western Hemisphere (WH) versus the Eastern Hemisphere (EH). The zonal (west to east) redistribution of FF aerosol emission since the 1980s leads to a weakening negative radiative forcing over the WH mid-to-high latitudes and an enhancing negative radiative forcing over the EH at lower latitudes. Overall, the FF aerosol leads to a northward shift of the Hadley cell and an equatorward shift of the Northern Hemisphere (NH) jet stream. Here, two sets of regional FF simulations (Fix_EastFF1920 and Fix_WestFF1920) are performed to separate the roles of zonally asymmetric aerosol forcings. We find that the WH aerosol forcing, located in the extratropics, dominates the northward shift of the Hadley cell by inducing an interhemispheric imbalance in radiative forcing. On the other hand, the EH aerosol forcing, located closer to the tropics, dominates the equatorward shift of the NH jet stream. The consistent relationship between the jet stream shift and the top-of-atmosphere net solar flux (FSNTOA) gradient suggests that the latter serves as a rule-of-thumb guidance for the expected shift of the NH jet stream. The surface effect of EH aerosol forcing (mainly from low- to midlatitudes) is confined more locally and only induces weak warming over the northeastern Pacific and North Atlantic. In contrast, the WH aerosol reduction leads to a large-scale warming over NH mid-to-high latitudes that largely offsets the cooling over the northeastern Pacific due to EH aerosols. The simulated competing roles of regional aerosol forcings in driving atmospheric circulation and surface temperature responses during the recent decades highlight the importance of considering zonally asymmetric forcings (west to east) and also their meridional locations within the NH (tropical vs. extratropical).

The multi-decadal variations in the Pacific climate are extensively discussed as being influenced by external forcings such as greenhouse gases (GHGs) and anthropogenic aerosols (AAs). Unlike GHGs, the potential impacts of AAs could be more complex because of the heterogeneity of spatial distribution during the past few decades. Here we show, using regional aerosol forcing large-ensemble simulations with the Community Earth System Model 1 (CESM1), that the increasing fossil-fuel-related aerosol emissions over Asia (EastFF) and the reduction in aerosol emissions over North America and Europe (WestFF) have remarkably different impacts on driving the Pacific circulations and sea surface temperature (SST) changes since the 1980s. EastFF excites a typical El Niño-like SST pattern in the tropical Pacific and weakens the climatological Pacific Walker circulation. WestFF induces a central Pacific (CP)-type El Niño-like SST pattern with warming in the middle region of the equatorial Pacific, which is consistent with the second leading empirical orthogonal function (EOF) pattern of the observation. Over the North Pacific region, EastFF, located at low to middle latitudes, favors an Interdecadal Pacific Oscillation (IPO)-like SST pattern (horseshoe-like SST pattern in the North Pacific) through a teleconnection pathway between the tropical and extratropical Pacific but is overwhelmed by internal variability evolving from a positive phase to a negative IPO phase. In contrast, WestFF, located at middle to high latitudes, strongly affects the North Pacific via a west-to-east mid-latitude pathway and induces extensive warming. The competing effects of the heterogeneously distributed regional aerosol forcings are expected to exhibit different patterns in the near future, especially the redistribution of aerosol emissions within the domain of EastFF (i.e., from East Asia to South Asia) and changes in aerosol composition. The complex future changes in anthropogenic aerosol emissions are likely to introduce more profound impacts of aerosol forcing on the Pacific multi-decadal variations.

Mild or moderate hypothermia (>30 degrees C) has been proposed for clinical use as a therapeutic option for achieving protection from cerebral ischaemia in brain injury patients. In this research, a theoretical model was developed to examine the brain temperature gradients during selective cooling of the brain surface after head injury. The head was modelled as a hemisphere consisting of several layers, representing the scalp, skull and brain tissue, respectively. The dimensions, physical properties and physiological characteristics for each layer, as well as the arterial blood temperature, were used as the input to the Pennes bioheat transfer equation to simulate the steady-state temperature distribution within the brain. Depending on the head surface temperature, a temperature gradient of up to 13 degrees C exists in the brain tissue. The results have shown that the volumetric-averaged brain tissue temperature Tbt,avg for adults and infants can be 1.7 and 4.3 degrees C, respectively, lower than the temperature of the arterial blood supplied to the brain tissue. The location where the probe should be placed to measure Tbt,avg was also determined by the simulation. The calculation suggests that the temperature sensor should be placed 7.5mm and 5.9 mm beneath the brain tissue surface for adults and infants, respectively, to monitor Tbt,avg continuously.