Polyacrylonitrile-Nanofiber-Based Gel Polymer Electrolyte for Novel Aqueous Sodium-Ion Battery Based on a Na4Mn9O18 Cathode and Zn Metal Anode

A gel polymer electrolyte was formed by trapping an optimized Na+/Zn2+ mixed-ion aqueous electrolyte in a polyacrylonitrile nanofiber polymer matrix. This electrolyte was used in a novel aqueous sodium-ion battery (ASIB) system, which was assembled by using a zinc anode and Na4Mn9O18 cathode. The nanorod-like Na4Mn9O18 was synthesized by a hydrothermal soft chemical reaction. The structural and morphological measurement confirmed that the highly crystalline Na4Mn9O18 nanorods are uniformly distributed. Electrochemical tests of Na4Mn9O18//Zn gel polymer battery demonstrated its high cycle stability along with a good rate of performance. The battery delivers an initial discharge capacity of 96 mAh g−1 , and 64 mAh g−1 after 200 cycles at a high cycling rate of 1 C. Our results demonstrate that the Na4Mn9O18//Zn gel polymer battery is a promising and safe high-performance battery

ZnO Nanorods Grown Directly on Copper Foil Substrate as a Binder-Free Anode for High Performance Lithium-Ion Batteries

ZnO nanorods directly grown on copper foil substrate were obtained via hydrothermal method without using templates. Structure and morphology of the as-prepared ZnO nanorods were characterized by X-ray diffraction, scanning electron microscopy and high-resolution transmission electron microscopy. The ZnO nanorods on copper foil (ZnO@CF) exhibited remarkably enhanced performance as anode for lithium batteries with the initial discharge capacity of 1236 mAh g-1 and a capacity of 402 mAh g-1 retained over 100 cycles at a current density of 200 mA g-1. The ZnO@CF anode demonstrated an excellent rate capability, delivering a reversible capacity of 390 mAh g-1 at 1500 mA g-1. This superior performance of the ZnO@CF anode is believed to be due to the unique structure of this binder-free anode, favoring mass and charge transfer at its interface with the electrolyte, effectively reducing the Li-ions diffusion paths and providing conditions to accommodate the anode volume variations upon charge-discharge cycling

Watt-level femtosecond Tm-doped “mixed” sesquioxide ceramic laser in-band pumped by a Raman fiber laser at 1627 nm

We report on a semiconductor saturable absorber mirror mode-locked Tm:(Lu,Sc)2O3 ceramic laser in-band pumped by a Raman fiber laser at 1627 nm. The nonlinear refractive index (n2) of the Tm:(Lu,Sc)2O3 ceramic has been measured to be 4.66 × 10-20 m2/W at 2000 nm. An average output power up to 1.02 W at 2060 nm is achieved for transform-limited 280-fs pulses at a repetition rate of 86.5 MHz, giving an optical efficiency with respect to the absorbed pump power of 36.4%. Pulses as short as 66 fs at 2076 nm are produced at the expense of output power (0.3 W), corresponding to a spectral bandwidth of 69 nm. The present work reveals the potential of Tm3+-doped sesquioxide transparent ceramics for power scaling of femtosecond mode-locked bulk lasers emitting in the 2-μm spectral range

Volumetry of low-contrast liver lesions with CT: Investigation of estimation uncertainties in a phantom study

Purpose: To evaluate the performance of lesion volumetry in hepatic CT as a function of various imaging acquisition parameters. Methods: An anthropomorphic abdominal phantom with removable liver inserts was designed for this study. Two liver inserts, each containing 19 synthetic lesions with varying diameter (6–40 mm), shape, contrast (10–65 HU), and both homogenous and mixed-density were designed to have background and lesion CT values corresponding to arterial and portal-venous phase imaging, respectively. The two phantoms were scanned using two commercial CT scanners (GE 750 HD and Siemens Biograph mCT) across a set of imaging protocols (four slice thicknesses, three effective mAs, two convolution kernels, two pitches). Two repeated scans were collected for each imaging protocol. All scans were analyzed using a matched-filter estimator for volume estimation, resulting in 6080 volume measurements across all of the synthetic lesions in the two liver phantoms. A subset of portal venous phase scans was also analyzed using a semi-automatic segmentation algorithm, resulting in about 900 additional volume measurements. Lesions associated with large measurement error (quantified by root mean square error) for most imaging protocols were considered not measurable by the volume estimation tools and excluded for the statistical analyses. Imaging protocols were grouped into distinct imaging conditions based on ANOVA analysis of factors for repeatability testing. Statistical analyses, including overall linearity analysis, grouped bias analysis with standard deviation evaluation, and repeatability analysis, were performed to assess the accuracy and precision of the liver lesion volume biomarker. Results: Lesions with lower contrast and size ≤10 mm were associated with higher measurement error and were excluded from further analysis. Lesion size, contrast, imaging slice thickness, dose, and scanner were found to be factors substantially influencing volume estimation. Twenty-four distinct repeatable imaging conditions were determined as protocols for each scanner with a fixed slice thickness and dose. For the matched-filter estimation approach, strong linearity was observed for all imaging data for lesions ≥20 mm. For the Siemens scanner with 50 mAs effective dose at 0.6 mm slice thickness, grouped bias was about −10%. For all other repeatable imaging conditions with both scanners, grouped biases were low (−3%–3%). There was a trend of increasing standard deviation with decreasing dose. For each fixed dose, the standard deviations were similar among the three larger slice thicknesses (1.25, 2.5, 5 mm for GE, 1.5, 3, 5 mm for Siemens). Repeatability coefficients ranged from about 8% to 75% and showed similar trend to grouped standard deviation. For the segmentation approach, the results led to similar conclusions for both lesion characteristic factors and imaging factors but with increasing magnitude in all the error metrics assessed. Conclusions: Results showed that liver lesion volumetry was strongly dependent on lesion size, contrast, acquisition dose, and their interactions. The overall performances were similar for images reconstructed with larger slice thicknesses, clinically used pitches, kernels, and doses. Conditions that yielded repeatable measurements were identified and they agreed with the Quantitative Imaging Biomarker Alliance’s (QIBA) profile requirements in general. The authors’ findings also suggest potential refinements to these guidelines for the tumor volume biomarker, especially for soft-tissue lesions

Fermented Grains from Different Layers of Cellar in the First and Second Rounds of Fermentation of Maotai-Flavor Baijiu: Analysis of microbial community structure and Acid Composition as Well as Correlation between Them

In this study, the microbial community structure in fermented grains from the upper middle and lower layers of the cellar in the first and second rounds of fermentation of Maotai-flavor was analyzed by high-throughput sequencing, and the acid composition by ultra-high performance liquid chromatography (UPLC). Moreover, the correlation between them was investigated. The results showed that the total acid content of fermented grains was greater in the second round than the first round of fermentation. The radial distribution patterns of seven acidic compounds in different times and spaces of the cellar were different. The contents of lactic acid and acetic acid accounted for a large proportion in the two rounds of fermentation. For both rounds, the absolutely dominant bacterial genus was Limosilactobacillus, and the dominant fungal genera were Saccharomyces and Candida. As the fermentation time extended, there was a significant difference in the microbial community structure. The contents of total and individual acids were positively correlated with the relative abundance of Limosilactactacillacus, Schizosaccharomyces, Zygosaccharomyces, Candida and Kazachstania, and negatively correlated with the relative abundance of Lactobacillus, Saccharomyces, Paecilomyces and Torulaspora. This study provides a theoretical basis for further elucidating the fermentation mechanism of Maotai-flavor Baijiu cellar

High-Power AlGaInAs/InP DFB Lasers with Low Divergence Angle

High-power semiconductor DFB lasers with low divergence angle fundamental transverse mode operating at wavelengths near 1.31 μm have many applications such as analog and digital fiber communication, WDM pump sources, spectroscopy, remote sensing, free-space communication, laser-based radar, and wavelength conversion in nonlinear materials [1]. These devices can potentially reduce system costs by simplifying optical alignment and package processes [2]. Devices with narrow far-field patterns (FFPs) are highly desirable for simple, high-yield optical alignment, as a low divergence angle improves the coupling efficiency and imposes less stringent tolerances in the alignment between the device and the single-mode fiber (SMF). Until now most of the high-power low divergence angle 1.31 μm DFB laser is based on InGaAsP/InP material system which has lower characteristic temperature value T 0 [3]. Here we first demonstrate the high-power fundamental transverse mode 1.31 μm AlGaInAs/InP DFB laser with low divergence angle, enabling uncooled continuous-wave (CW) operation at high ambient temperatures

Stepped-height ridge waveguide MQW polarization mode converter monolithically integrated with sidewall grating DFB laser

We report the first demonstration of a 1555 nm stepped-height ridge waveguide polarization mode converter monolithically integrated with a side wall grating distributed-feedback (DFB) laser using the identical epitaxial layer scheme. The device shows stable single longitudinal mode (SLM) operation with the output light converted from TE to TM polarization with an efficiency of >94% over a wide range of DFB injection currents (IDFB) from 140 mA to 190 mA. The highest TM mode purity of 98.2% was obtained at IDFB=180 mA. A particular advantage of this device is that only a single step of metalorganic vapor-phase epitaxy and two steps of III-V material dry etching are required for the whole integrated device fabrication, significantly reducing complexity and cost

Regrowth-free AlGaInAs MQW polarization controller integrated with sidewall grating DFB laser

We report an AlGaInAs multiple quantum well integrated source of polarization controlled light consisting of a polarization mode converter PMC, differential phase shifter(DPS), and a side wall grating distributed-feedback DFB laser. We demonstrate an asymmetrical stepped-height ridge waveguide PMC to realize TE to TM polarization conversion and a symmetrical straight waveguide DPS to enable polarization rotation from approximately counterclockwise circular polarization to linear polarization. Based on the identical epitaxial layer scheme, all of the PMC, DPS, and DFB laser can be integrated monolithically using only a single step of metalorganic vapor phase epitaxy and two steps of III V material dry etching. For the DFB-PMC device, a high TE to TM polarization conversion efficiency 98% over a wide range of DFB injection currents is reported at 1555 nm wavelength. For the DFB-PMC-DPS device, a 60 degree rotation of the Stokes vector was obtained on the Poincar\'e sphere with a range of bias voltage from 0 V to -4.0 V at IDFB is 170 mA.Comment: arXiv admin note: text overlap with arXiv:2210.1051

Semiconductor saturable absorber mirror mode-locked Yb:YAP laser

We report on sub-30 fs pulse generation from a semiconductor saturable absorber mirror mode-locked Yb:YAP laser. Pumping by a spatially single-mode Yb fiber laser at 979 nm, soliton pulses as short as 29 fs were generated at 1091 nm with an average output power of 156 mW and a pulse repetition rate of 85.1 MHz. The maximum output power of the mode-locked Yb:YAP laser amounted to 320 mW for slightly longer pulses (32 fs) at an incident pump power of 1.52 W, corresponding to a peak power of 103 kW and an optical efficiency of 20.5%. To the best of our knowledge, this result represents the shortest pulses ever achieved from any solid-state Yb laser mode-locked by a slow, i.e., physical saturable absorber