Although defects can have a significant effect on the properties of amorphous materials, in many cases these defects are poorly characterized and understood. This is at least partly due to the difficulty of imaging defects in amorphous materials in the electron microscope. In this work, we demonstrate the utility of quantitative analysis of high-resolution transmission electron microscopy for the identification and characterization of nanometer-scale defects in metallic glasses. For a proper identification of such defects, it is important to carefully consider the effects of the imaging conditions and thickness variations in the sample, both of which we describe in detail. As an example, we show that regions of localized plastic deformation (shear bands) in bulk metallic glasses contain a high concentration of nanometer-scale voids. These voids apparently result from the coalescence of excess free volume once the applied stress is removed.
ABSTRACT Fish diversity is essential for maintaining the balance of aquatic ecosystems, particularly in rivers impacted by overfishing and hydropower projects, such as the Jinsha river, the upstream segment of the Yangtze river. During initial phases (August and November, 2023) of the 10‐year fishing ban in the Yangtze river basin, we investigated fish diversity, seasonal variations, and their correlation with environmental factors in the Jinsha river using environmental DNA (eDNA) metabarcoding. Utilizing two pairs of 12S rRNA primers, MiFish‐U and AcMDB07, we identified 61 fish species across 5 orders, 17 families, and 52 genera, including 4 national protected and 7 invasive alien fish. Among them, Cypriniformes constituted the predominant group within the fish community, accounting for 65.6%. This finding aligns with the results from a recent fish catch study, which recorded 68 species of fish belonging to 4 orders, 15 families, and 48 genera, including 4 national protected species and 8 invasive alien fish. The alpha diversity analysis revealed compositional differences in the fish community across various regions and seasons. Furthermore, key environmental factors, such as water temperature, dissolved oxygen, nitrate nitrogen, total suspended solids, and conductivity, were found to be highly correlated with fish diversity in the Jinsha river. Consequently, we provided detailed seasonal data on fish diversity and its correlations with environmental factors, which will aid in the systematic management and restoration of fisheries and the assessment of the 10‐year fishing ban in the Jinsha river.
Abstract Review: ca. 200 refs.
Singing in tune, or singing accuracy, is a construct dependent on genre, key selection, singers’ ranges, and listener expectations. But across genres, singers are expected to sing in tune with themselves and with others. Because singing a familiar song may be the most common communal singing situation in the lives of non-professional singers and students, we chose to examine previously reported data on the Happy Birthday song as representative of one typical example of a popular song globally and used in previous research. The participants were adult non-professional singers. We designed a predictive model of performance on the large ascending octave based on initial interval performance, providing implications for music education in children or adults and by exploring variables such as range, voice register, and key modulation. We conclude that while initial performance may predict subsequent performance, features such as singer’s range and starting pitch may also account for variability in individual performance.
We present a selective encoding method that reduces test data volume and test application time for scan testing of intellectual property (IP) cores. This method encodes the slices of test data that are fed to the scan chains in every clock cycle. Unlike many prior methods, the proposed method does not encode all the specified (0s and 1s) and unspecified (don't-care) bits in a slice. For example, if a slice contains more 1s than 0s, only the 0s are encoded and all don't-cares are mapped to 1. We use only c tester channels, where c = [log <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> (N + 1)] + 2, to drive N scan chains. In the best case, we can achieve compression by a factor of N/c using only one tester clock cycle per slice. We derive an upper bound on the density of care bits (either 1s or 0s) that allows us to achieve the best-case compression. The pattern decompression is of the continuous-flow type because no complex handshakes are required between the tester and the chip. Unlike popular compression methods such as EDT and SmartBIST, the proposed approach is suitable for IP cores because it does not require structural information for fault simulation, dynamic compaction, or interleaved test generation. The on-chip decoder is small, independent of the circuit under test and the test set, and it can be shared between different circuits. We present compression results for a number of industrial circuits, and compare our results to other recent compression methods targeted at IP cores. We show that up to 28times reduction in test data volume and 20times reduction in testing time is obtained for these circuits
Interface and defect structures of Zn–ZnO core–shell nanobelts have been investigated using high-resolution transmission electron microscopy. Most of the nanobelts can be classified into two types from their growth directions: [21̄1̄0] and [0001], with the top/bottom surfaces being (0001) and (21̄1̄0), respectively. The Zn core and ZnO shell overlapped areas display a two-dimensional moiré pattern resulting from the lattice mismatch. In the 〈21̄1̄0〉 growth nanobelts, a network of three sets of misfit dislocations relaxes the mismatch strain in the top/bottom interfaces, and every set rotates 60° with respect to the other; there are two types of grains oriented in specific orientations that compose the side wall of the ZnO shell. In the [0001] growth nanobelts, a network containing a set of stacking faults in (0001) planes and a set of misfit dislocations in (011̄0) planes takes the main role in the misfit relaxation. Threading dislocations indicated by terminating moiré fringes are present in both of them, which are located at the small angle rotated boundary between adjacent misoriented ZnO grains.
