Spatial mode-count scalability in optical fibers is of paramount importance for addressing the upcoming information-capacity crunch, reducing energy consumption per bit, and for enabling advanced ...quantum computing networks, but this scalability is severely limited by perturbative mode mixing. We show an alternative means of light guidance, in which light's orbital angular momentum creates a centrifugal barrier for itself, thereby enabling low-loss transmission of light in a conventionally forbidden regime wherein the mode mixing can be naturally curtailed. This enables kilometer-length-scale transmission of a record ~50 low-loss modes with cross-talk as low as -45 decibels/kilometer and mode areas of ~800 square micrometers over a 130-nanometer telecommunications spectral window. This distinctive light-guidance regime promises to substantially increase the information content per photon for quantum or classical networks.
With growing interest in the spatial dimension of light, multimode fibers, which support eigenmodes with unique spatial and polarization attributes, have experienced resurgent attention. Exploiting ...this spatial diversity often requires robust modes during propagation, which, in realistic fibers, experience perturbations such as bends and path redirections. By isolating the effects of different perturbations an optical fiber experiences, we study the fundamental characteristics that distinguish the propagation stability of different spatial modes. Fiber perturbations can be cast in terms of the angular momentum they impart on light. Hence, the angular momentum content of eigenmodes (including their polarization states) plays a crucial role in how different modes are affected by fiber perturbations. We show that, accounting for common fiber-deployment conditions, including the more subtle effect of light’s path memory arising from geometric Pancharatnam–Berry phases, circularly polarized orbital angular momentum modes are the most stable eigenbasis for light propagation in suitably designed fibers. Aided by this stability, we show a controllable, wavelength-agnostic means of tailoring light’s phase due to its geometric phase arising from path memory effects. We expect that these findings will help inform the optimal modal basis to use in the variety of applications that envisage using higher-order modes of optical fibers.
It is a common method to resolve three-dimensional (3-D) deformation components associated with underground mining by incorporating Single-track interferometric synthetic aperture radar (InSAR) with ...a prior deformation model termed linear proportion model (LPM) (hereinafter referred to as Sin-LPM). Nevertheless, the Sin-LPM method relies on three model parameters that are needed to be in situ collected, and it neglects their dynamic changes during the period of underground extraction, narrowing the practical applications of the Sin-LPM method, and degrading the accuracy of the estimated 3-D displacements. In this article we propose a new method to resolve 3-D mining displacements from multi-track InSAR observations by incorporating with the LPM. In which, the model parameters are first considered as dynamic and further adaptively estimated from the multi-track InSAR observations using a robust solver. Following that, 3-D mining displacements are resolved from the multi-track InSAR using the conjugate gradient method (CGM). The proposed method was tested in Datong coalfield, China. The results suggest that the proposed method can well estimate 3-D mining displacements with a mean error of about 1.8 cm. Compared with the previous Sin-LPM, the proposed method can effectively improve the accuracy of the estimated 3-D displacements (e.g., 69% in this study), and can work well even over a large area where the model parameters are unknown. The proposed method offers a new insight to improve the InSAR-based retrieval of 3-D displacements induced by other anthropologic or geophysical activities.
The O3-type layered Mn-based oxide has been considered as one of the most promising cathodes for high-performance and large-scale sodium-ion batteries due to its highly reversible capacity, easy mass ...production, low-toxic elemental content etc. However, the fragile interface induced by air sensitivity, potential dissolution of manganese ions in electrolytes, and low electric conductivity in this cathode often cause severe degradation of the layered structure and rapid fading of reversible capacity at room temperature, and even more so in other temperature ranges. Herein, a defective Al(II, III)Ox nanointerface has uniformly been coated on the surface of an O′3-NaMn0.6Al0.4O2 (NMA) cathode by a one-step solid calcination with surface segregation and reconstruction from substituted Al-enrichment. This amorphous AlOx overlayer possesses abundant oxygen vacancies induced by the generation of Al2+ and exhibits ultrahigh conductivity and stability, which enable the NMA@AlOx cathode to deliver a high discharge capacity of 155 mA h g−1, a highly enhanced rate capability and outstanding cycling performance at room temperature. Furthermore, NMA@AlOx also continues to exhibit highly effective Na-storage behaviors with small fluctuations in a wide temperature range from −20 to 60 °C. This design could provide a promising route to broaden the applications of sensitive electrode materials for high-performance and wide-temperature Na-storage devices.
The kinetic behaviors of polysulfides related to sluggish/incomplete conversion and repeated shuttles are the key factors behind the unsatisfactory performance of Li-S batteries. Herein, an ...Au-decorated covalent organic framework/graphene (Au-COF/rGO) is employed to construct a multifunctional interface to solve such issues. The narrow porous structure of COF can confine the diffused polysulfides
via
a physical barrier, and Au can further anchor and facilitate the catalytic conversion of intercepted polysulfides. Meanwhile, the well-conducting rGO nanosheets are also able to act as an upper current collector to activate polysulfides to quickly participate in the next electrochemical reaction. Thus, an orderly connection between the confinement-capture-conversion of polysulfides is formed. Additionally, the good lithium affinity of Au and imine linkages on COF can promote Li
+
diffusion, achieving a fast charge of batteries. Attributed to the multi merits of the Au-COF/rGO interface, the assembled Li-S batteries not only deliver an ultra-high specific capacity (1525 mA h g
−1
at 0.1C) with a prominent rate performance (568 mA h g
−1
at 4C), but also exhibit outstanding cycling performance in both the cases of conventional and high sulfur loadings. The rational design of the Au-COF/rGO interface provides a new insight into developing advanced Li-S batteries.
Au-COF/rGO was designed to build a multifunctional interface, which can form an orderly connection between confinement-capture-conversion of polysulfides and promote the diffusion of Li
+
, achieving outstanding performance of Li-S batteries.
Development of highly stabilized and reversible cathode materials has become a great challenge for sodium‐ion batteries. O′3‐type layered Mn‐based oxides have deserved much attention as one of ...largely reversible‐capacity cathodes featured by the resource‐rich and low‐toxic elements. However, the fragile slabs structure of typical layered oxides, low Mn‐ion migration barriers, and Jahn–Teller distortion of Mn3+ have easily resulted in the severe degradation of cyclability and rate performances. Herein, a new queue‐ordered superstructure is built up in the O′3‐NaMn0.6Al0.4O2 cathode material. Through the light‐metal Al substitution in O′3‐NaMnO2, the MnO6 and AlO6 octahedrons display the queue‐ordered arrangements in the transition metal (TM) slabs. Interestingly, the presence of this superstructure can strengthen the layered structure, reduce the influence from Jahn–Teller effect, and suppress the TM‐ions migrations during long‐terms cycles. These characteristics results in O′3‐NaMn0.6Al0.4O2 cathode deliver a high capacity of 160 mAh g−1, an enhanced rate capability and the excellent cycling performance. This research strategy can provide the broaden insight for future electrode materials with high‐performance sodium‐ions storage.
A novel queue‐order NaMn0.6Al0.4O2 (NMA) is first prepared as high‐performance cathode material for sodium‐ion battery. The NMA exhibits a firmed layered structure based on queue‐ordered Mn0.6Al0.4O2 slabs, which result in NMA cathode delivers a high practical capacity of 160 mAh g−1, a remarkable rate performance and an excellent cycling life of 81% retention after 100 cycles.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Seawater electrolysis is a viable method for producing hydrogen on a large scale and low-cost. However, the catalyst activity during the seawater splitting process will dramatically degrade as salt ...concentrations increasing. Herein, CoP is discovered that could reject chloride ions far from catalyst in electrolyte based on molecular dynamic simulation. Thus, a binder-free electrode is designed and constructed by in-situ growth of homogeneous CoP on rGO nanosheets wrapped around the surface of Ti fiber felt for seawater splitting. As expected, the as-obtained CoP/rGO@Ti electrode exhibits good catalytic activity and stability in alkaline electrolyte. Especially, benefitting from the highly effective repulsive Cl
intrinsic characteristic of CoP, the catalyst maintains good catalytic performance with saturated salt concentration, and the overpotential increasing is less than 28 mV at 10 mA cm
from 0 M to saturated NaCl in electrolyte. Furthermore, the catalyst for seawater splitting performs superior corrosion-resistance with a low solubility of 0.04%. This work sheds fresh light into the development of efficient HER catalysts for salinity tolerance hydrogen evolution.
It is common to estimate underground mining-induced subsidence from interferometric synthetic aperture radar (InSAR) displacement observations by Neglecting hOrizontal moVements (NOV). Such a ...strategy would cause large errors in the NOV-estimated subsidence. This issue was proven and the theoretical equation of the resulting errors has been deduced before. However, the systematic analysis of the error pattern (e.g., spatial distribution) and its relationship between some critical influence factors (e.g., lithology of overlying rock strata) is lacking to date. To circumvent this, a method was first presented to assess the errors of the NOV-estimated mining subsidence in this study. Then, the error pattern and the influence factors of the NOV-estimated mining subsidence were discussed. The results suggest that the errors of the NOV-estimated mining subsidence spatially follow a “peak-to-valley” shape, with an absolute “peak-to-valley angle” of 5–15°. In addition, for the same underground mining geometry, the error magnitudes of the NOV-estimated mining subsidence under hard lithology of overlying rock strata are smaller than those under soft lithology, and vice versa. These results would be beneficial to guide the scientific use of the NOV method for understanding the deformation mechanism and controlling the geohazards associated with underground mining and other similar anthropogenic activities.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The recent discovery of memristive devices based on two-dimensional materials have attracted much interest for emerging applications on flexible memory, neuromorphic computing, and so forth. Reducing ...the thickness to a single-layer level would prompt the scaling limit to sub-nanometer. However, monolayer materials based vertical memristive devices generally suffer inferior performance with high operating voltage, large leakage currents, and poor reliability. In this study, an interfacial polymer layer is inserted between the monolayer hexagonal boron nitride (h-BN) and top electrodes, which not only helps to constrain the conducting filament size but also block the formation of excess filaments from the bottom Cu foil. Therefore, the device shows stable bipolar resistive switching behavior with low operating voltage (< 500 mV), large on/off ratio (up to 105), long retention time (> 105 s), and excellent flexibility. It is demonstrated that tunneling conduction is shown in off-state and on-state current conducts via metallic conducting filaments, which are formed by the substitute of metal ions for lattice vacancies in h-BN. This work presents a scalable interface engineering strategy to control the interactions between metal ions and defects in monolayer h-BN films and sheds light on their promising application for large-scale integrated ultrathin flexible memory.
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•Memristive device based on monolayer hexagonal boron nitride is demonstrated.•An interfacial polymer layer is inserted to constrain the conducting filament size and numbers.•The device shows low operating voltage (< 500 mV), large on/off ratio, long retention time, and excellent flexibility.•Tunneling conduction is shown in off-state and on-state current conducts via metallic conducting filaments.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Objectives
Reports about the radiologic features of minute pulmonary meningothelial-like nodules are sparse. This study aims to investigate the radiologic features of minute pulmonary ...meningothelial-like nodules.
Method
From January 2016 to April 2019, 7589 patients underwent pulmonary resections at Fudan University Shanghai Cancer Center. Postoperative pathology records were reviewed retrospectively. Fifty-nine patients with minute pulmonary meningothelial-like nodule were included. The identification of minute pulmonary meningothelial-like nodules in pathology specimen included pathologically confirmed in resected nodules, and discovery in the peripheral tissue of other resected nodules incidentally. We went back and checked all the pre-operative scans of patients to analyze surgical decision and observe any change of visible minute pulmonary meningothelial-like nodule over time. Clinic, radiologic and pathological features were collected.
Result
Fifty-nine patients included 10 men and 49 women, with a mean age of 57.7. Five patients had history, while 54 patients were non-smokers. 79 min pulmonary meningothelial-like nodules was found. Of them, 36 nodules were not visible on computed tomography scan. 43 nodules were visible on computed tomography scan, with an average size of 5.3 mm in 29 patients. Computed tomography appearance included pure ground-glass opacity in 36, mixed in 2, and solid nodules in 5. Nearly half of patients had a pre-operative follow-up more than 6 months (13/29, 44.8%). The median pre-operative radiologic follow-up was 4.9 months. Approximately 90% of patients underwent pulmonary surgery because of other malignant nodule on chest computed tomography scan (52/59, 88.1%).
Conclusion
Most minute pulmonary meningothelial-like nodules tend to present as ground-glass opacity, especially pure ground-glass opacity. Continuous computed tomography monitoring revealed no radiologic change over time. Continuous computed tomography monitoring was necessary part of management of minute pulmonary meningothelial-like nodule.
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EMUNI, FZAB, GEOZS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NUK, OILJ, PNG, SAZU, SBCE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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