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Atomically thin indium selenide (InSe) exhibits a sombrero-like valence band, leading to distinctive excitonic behaviors. It is known that the indirect band gap of atomically thin InSe leads to a weak emission from the lowest-energy excitonic state (A peak). However, the A peak emission of monolayer (ML) InSe was observed to be either absent or very weak, rendering the nature of its excitonic states largely unknown. Intriguingly, we demonstrate that ML InSe exhibits pronounced PL emission because of the efficient brightening of the momentum-indirect dark excitons. The mechanism is attributed to acoustic phonon-assisted radiative recombination facilitated by strong exciton-acoustic phonon coupling and extended wavefunction in momentum space. Systematic analysis of layer-, power-, and temperature-dependent PL demonstrates that a carrier localization model can account for the asymmetric line shape of the lowest-energy excitonic emission for atomically thin InSe. Our work reveals that atomically thin InSe is a promising platform for manipulating the tightly bound dark excitons in two-dimensional semiconductor-based optoelectronic devices. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to develop a regionalized characterization model of water consumption that can delineate what the potential damage receptors are and where they will be. In order to improve local water resources management, assessment results with more accurate spatial information are needed. This model could be used to derive regionalized life cycle assessment (LCA) results, especially for evaluations within a country. Methods: We developed a regionalized characterization model using a watershed-affected matrix and related factors. To construct the watershed-affected matrix, a watershed-affected area (WAA) describing the geographical boundary that will be affected by insufficient water supply from the watershed was proposed as a spatial scale to evaluate the impacts of local water consumption. The model could be performed with input water consumption inventory data carrying watershed scale attributes, and with output damage results carrying local administrative scale attributes. The area of concern (AoC) concept was applied to the model so that water consumption users, such as domestic, agricultural, and industrial sectors, could be used as damage receptor to reveal societal concern about which sector will be influenced due to water depletion. Results and discussion: This regionalized characterization model was tested on the three main watersheds in Taiwan, each representing typical, but different, water-usage features. Sector-wise WAAs of each watershed were constructed, and endpoint characterization factors (CFs) of local water consumption were calculated. The visualization results show the damage distribution of water consumption among the damage receptors, which used to be a single average value at the watershed or national scale. Conclusions: The model with the AoC concept is sufficiently flexible for choosing representative affected users and outcome indicators according to stakeholder preferences. Spatial differentiation and comparable results can also support LCA interpretation with detailed information. This model is expected to be further applied to the development of damage prevention strategies. [ABSTRACT FROM AUTHOR]

In this paper, we propose an adaptive reversible steganographic scheme based on the just noticeable distortion (JND). First, the JND value of each cover pixel is calculated using the frequency model of the human visual system (HVS). Then, the prediction value of the cover pixel is acquired by anisotropic interpolation, and also the pixel distribution characteristic is estimated. Finally, whether the cover pixel is embeddable or not is adaptively determined according to the relationship between the prediction error and the JND value. The embedding procedure is based on modifying the prediction error of each cover pixel, and the visual degradation caused by embedding is imperceptible due to the control of JND. Experimental results demonstrate that the proposed scheme provides a greater embedding rate and higher quality of stego image than other methods that have been reported recently. [ABSTRACT FROM AUTHOR]

A simplified one-diode one-resistor (1D1R) resistive switching memory cell that uses only four layers of TaN/ZrTiO/Ni/n-Si was proposed to suppress sneak current where TaN/ZrTiO/Ni can be regarded as a resistive-switching random access memory (RRAM) device while Ni/n-Si acts as an Schottky diode. This is the first RRAM cell structure that employs metal/semiconductor Schottky diode for current rectifying. The 1D1R cell exhibits bipolar switching behavior with SET/RESET voltage close to 1 V without requiring a forming process. More importantly, the cell shows tight resistance distribution for different states, significantly rectifying characteristics with forward/reverse current ratio higher than 10 and a resistance ratio larger than 10 between two states. Furthermore, the cell also displays desirable reliability performance in terms of long data retention time of up to 10 s and robust endurance of 10 cycles. Based on the promising characteristics, the four-layer 1D1R structure holds the great potential for next-generation nonvolatile memory technology. [ABSTRACT FROM AUTHOR]

Lactobacillus pobuzihii is a novel species which has been previously found in pobuzihi (fermented cummingcordia), a traditional fermented food in Taiwan. However, the lactic acid bacteria (LAB) microflora in pobuzihi has not been studied in detail. In this study, LAB from pobuzihi were isolated, identified, and characterized. A total of 196 LAB were isolated; 79 cultures were isolated from the sample collected from a manufacturing factory, 38 from pobuzihi samples collected from 4 different markets, and 79 from 2 fresh cummingcordia samples. These isolates were characterized phenotypically and then divided into eight groups (A to H) by restriction fragment length polymorphism analysis and sequencing of 16S ribosomal DNA. Lactobacillus plantarum was the most abundant LAB found in most samples during the fermentation of pobuzihi. On the other hand, Enterococcus casseliflavus and Weissella cibaria were, respectively, the major species found in the two fresh cummingcordia samples. A potential novel species or subspecies of lactococcal strain was found. In addition, seven L. plantarum and five W. cibaria strains showed inhibitory activity against the indicator strain Lactobacillus sakei JCM 1157. This is the first report describing the distribution and varieties of LAB existing in the pobuzihi during its fermentation process and the final product on the market. [ABSTRACT FROM AUTHOR]