The effect of the relative grain size
d/
D (
d: grain size,
D: wire diameter) on stress–strain characteristics was investigated in Cu–Al–Mn-based shape memory alloy (SMA) wires. The yield stress (
σ
...y), the work-hardening rate after yielding (d
σ
PE/d
ε) and the stress hysteresis (Δ
σ) in the wires with a random texture decrease with increasing
d/
D. The transformation strain (
ε
TS) and the maximum pseudoelastic strain
(
ε
PE
MAX
)
increase with increasing
d/
D. The effect of grain size on pseudoelastic behaviors can be clarified from the volume fraction of three-dimensionally constrained grains and the
σ
y, d
σ
PE/d
ε and Δ
σ increase proportionally with increasing (1
−
(
d/
D))
2 while the
ε
TS decreases proportionally with increasing (1
−
(
d/
D))
2. Consequently, the effect of grain size on the pseudoelastic behaviors can be expressed using the Taylor and inverse Schmid factors. The
σ
y and the
ε
TS for wires with a 〈1
1
0〉 fiber texture are larger and smaller than those for wires with a random texture, respectively.
Spin dynamics evolution of BaFe2(As(1-x)Px){2} was probed as a function of P concentration via 31P NMR. Our NMR study reveals that two-dimensional antiferromagnetic (AF) fluctuations are notably ...enhanced with little change in static susceptibility on approaching the AF phase from the superconducting dome. Moreover, the magnetically ordered temperature θ deduced from the relaxation rate vanishes at optimal doping. These results provide clear-cut evidence for a quantum-critical point, suggesting that the AF fluctuations associated with the quantum-critical point play a central role in the high-T(c) superconductivity.
Plant microbiome and its manipulation inaugurate a new era for plant biotechnology with the potential to benefit sustainable crop production. Here, we used the large-scale 16S rDNA sequencing ...analysis to unravel the dynamic, structure, and composition of exophytic and endophytic microbial communities in two hybrid commercial cultivars of sugarcane (R570 and SP80-3280), two cultivated genotypes (Saccharum officinarum and Saccharum barberi) and one wild species (Saccharum spontaneum). Our analysis identified 1372 amplicon sequence variants (ASVs). The microbial communities' profiles are grouped by two, root and bulk soils and stem and leave when these four components are compared. However, PCoA-based data supports that endophytes and epiphytes communities form distinct groups, revealing an active host-derived mechanism to select the resident microbiota. A strong genotype-influence on the assembly of microbial communities in Saccharum ssp. is documented. A total of 220 ASVs persisted across plant cultivars and species. The ubiquitous bacteria are two potential beneficial bacteria, Acinetobacter ssp., and Serratia symbiotica. The results presented support the existence of common and cultivar-specific ASVs in two commercial hybrids, two cultivated canes and one species of Saccharum across tissues (leaves, stems, and roots). Also, evidence is provided that under the experimental conditions described here, each genotype bears its microbial community with little impact from the soil conditions, except in the root system. It remains to be demonstrated which aspect, genotype, environment or both, has the most significant impact on the microbial selection in sugarcane fields.
Abstract
Kondo lattice materials, where localized magnetic moments couple to itinerant electrons, provide a very rich backdrop for strong electron correlations. They are known to realize many exotic ...phenomena, with a dramatic example being recent observations of quantum oscillations and metallic thermal conduction in insulators, implying the emergence of enigmatic charge-neutral fermions. Here, we show that thermal conductivity and specific heat measurements in insulating YbIr
3
Si
7
reveal emergent neutral excitations, whose properties are sensitively changed by a field-driven transition between two antiferromagnetic phases. In the low-field phase, a significant violation of the Wiedemann-Franz law demonstrates that YbIr
3
Si
7
is a charge insulator but a thermal metal. In the high-field phase, thermal conductivity exhibits a sharp drop below 300 mK, indicating a transition from a thermal metal into an insulator/semimetal driven by the magnetic transition. These results suggest that spin degrees of freedom directly couple to the neutral fermions, whose emergent Fermi surface undergoes a field-driven instability at low temperatures.
A hydrogen-like atom consisting of a positive muon and an electron is known as muonium. It is a near-ideal two-body system for a precision test of bound-state theory and fundamental symmetries. The ...MuSEUM collaboration performed a new precision measurement of the muonium ground-state hyperfine structure at J-PARC using a high-intensity pulsed muon beam and a high-rate capable positron counter. The resonance of hyperfine transition was successfully observed at a near-zero magnetic field, and the muonium hyperfine structure interval of νHFS=4.463302(4)GHz was obtained with a relative precision of 0.9 ppm. The result was consistent with the previous ones obtained at Los Alamos National Laboratory and the current theoretical calculation. We present a demonstration of the microwave spectroscopy of muonium for future experiments to achieve the highest precision.
Abstract Uniaxial pressure provides an efficient approach to control charge density waves in YBa 2 Cu 3 O y . It can enhance the correlation volume of ubiquitous short-range two-dimensional ...charge-density-wave correlations, and induces a long-range three-dimensional charge density wave, otherwise only accessible at large magnetic fields. Here, we use x-ray diffraction to study the strain dependence of these charge density waves and uncover direct evidence for a form of competition between them. We show that this interplay is qualitatively described by including strain effects in a nonlinear sigma model of competing superconducting and charge-density-wave orders. Our analysis suggests that strain stabilizes the 3D charge density wave in the regions between disorder-pinned domains of 2D charge density waves, and that the two orders compete at the boundaries of these domains. No signatures of discommensurations nor of pair density waves are observed. From a broader perspective, our results underscore the potential of strain tuning as a powerful tool for probing competing orders in quantum materials.
The effects of the addition of Nb and B on grain boundary precipitation, martensitic transformation and superelasticity were investigated in the Fe–Ni–Co–Al alloys. The addition of Nb increases the ...hardness and the martensitic transformation changes from non-thermoelastic to thermoelastic, while the addition of B is effective for suppressing the formation of brittle grain boundary precipitates. By the recrystallization texture developed by 98.5% cold-rolling and annealing, high ductility and superelasticity with 5% recoverable strain were realized in the Fe–28Ni–17Co–10.5Al–2.5Nb–0.05B polycrystalline alloy.
Martensitic and magnetic transformation behaviors of Ni^sub 50^MnIn, Ni^sub 45^Co^sub 5^MnIn, and Ni^sub 42.5^ Co^sub 7.5^MnIn Heusler alloys were investigated by differential scanning calorimetry ...(DSC), vibrating sample magnetometry (VSM), and transmission electron microscopy (TEM). The martensitic transformation starting temperature (M^sub s^) decreases with increasing In composition, while the Curie temperatures (T^sub c^) of the parent phase are almost independent in each alloy series. On the other hand, the addition of Co resulted in a decrease of the M^sub s^ and an increase of the T^sub c^, and the degree of the decline of M^sub s^ was accelerated by magnetic transformation of the parent phase. The M^sub s^ temperature change induced by the magnetic field was also confirmed. It was found that the degree of M^sub s^ change is strongly related to the entropy change by the martensitic transformation, which shows a correlation with T^sub c^-M^sub s^. These behaviors can be qualitatively explained on the basis of thermodynamic considerations. PUBLICATION ABSTRACT
The impacts of climate change on snow distribution through the 21st century were investigated over three mountainous watersheds in Northern California by means of a physically-based snow distribution ...model. The future climate conditions during a 90-year future period from water year 2010 to 2100 were obtained from 13 future climate projection realizations from two GCMs (ECHAM5 and CCSM3) based on four SRES scenarios (A1B, A1FI, A2, and B1). The 13 future climate projection realizations were dynamically downscaled at 9 km resolution by a regional climate model. Using the downscaled variables based on the 13 future climate projection realizations, snow distribution over the Feather, Yuba, and American River watersheds (FRW, YRW, and ARW) was projected by means of the physically-based snow model. FRW and YRW watersheds cover the main source areas of the California State Water Project (SWP), and ARW is one of the key watersheds in the California Central Valley Project (CVP). SWP and CVP are of great importance as they provide and regulate much of the California's water for drinking, irrigation, flood control, environmental, and hydro-power generation purposes. Ensemble average snow distribution over the study watersheds was calculated over the 13 realizations and for each scenario, revealing differences among the scenarios. While the snow reduction through the 21st century was similar between A1B and A2, the snow reduction was milder for B1, and more severe for A1FI. A significant downward trend was detected in the snowpack over nearly the entire watershed areas for all the ensemble average results.
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•Snow conditions over three watersheds in California for 2010–2100 were projected.•A physically-based snow model was used to simulate future snow conditions.•The downward trend in snowpack is significant over nearly the entire watersheds.•Snowpack reduction is large at high elevation areas during the snow melting period.
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