ZnxCd1–xS single‐crystal nanoribbons of controlled composition (where 0 ≤ x ≤ 1) can be synthesized by combining laser ablation with thermal evaporation. The nanoribbons (see Figure) exhibit lasing ...emission that can be continuously tuned within the ranges of 340–390 nm and 485–515 nm. These results suggest that ZnxCd1–xS nanoribbon lasers of pre‐selected “tunable” wavelengths between 340 and 515 nm may be achievable by tailoring the value of x.
Soil bacteria play a key role in nutrient cycling, but the mechanisms behind seasonal variation of bacterial communities in different types of soil remain unclear. In this study, the bacterial ...composition during four seasons and at four soil depths (0–10, 10–20, 20–40 and 40–60 cm) in a Betula albosinensis forest of the Qinling Mountains (southern Shaanxi Province, China) was investigated. Illumina 16S rRNA gene sequencing was used to analyse soil bacterial diversity and communities. The soil properties, including temperature, pH, water content, organic carbon and total nitrogen content, were determined. Soil bacterial diversity did not decrease with increasing depth, indicating that the bacterial communities in the top‐ and sub‐soil had adapted to the availability of different substrates at different depths. The Chao1 richness and Shannon diversity indices at the four depths typically decreased by 54.43–86.87% and 13.31–33.91%, respectively, from warm summer to cold winter, which was probably a result of the decrease in soil temperature. Moreover, the abundance of Acidobacteria increased with soil temperature, whereas the abundance of Bacteroidetes decreased with increasing temperature. Soil temperature accounted for 49% of the total variation among the bacterial taxa. Overall, the results suggested that changes in the bacterial communities were attributable to physiological adaptation, which was controlled by soil temperature.
Highlights
We assessed the effects of soil depth and season on soil bacterial community structure.
We used Illumina 16S rRNA sequencing to study bacterial diversity and community composition.
Changes in bacterial Shannon index with soil depth were influenced by carbon type, not quantity.
Soil temperature had important effects on bacterial communities and abundance.
Arrays of well‐aligned single‐crystal zinc oxide (ZnO) nanowires of uniform diameter and length have been synthesized on a (100) silicon substrate via a simple horizontal double‐tube system using ...chemical vapor transport and condensation method. X‐ray diffraction and transmission electron microscopy (TEM) characterizations showed that the as‐grown nanowires had the single‐crystal hexagonal wurtzite structure with detectable defects and a growth direction. Raman spectra revealed phonon confinement effect when compared with those of ZnO bulk powder, nanoribbons, and nanoparticles. Photoluminescence exhibited strong ultraviolet emission at 3.29 eV under 355 nm excitation and green emission at 2.21 eV under 514.5 nm excitation. No catalyst particles were found at the tip of the nanowires, suggesting that the growth mechanism followed a self‐catalyzed and saturated vapor–liquid–solid (VLS) model. Self‐alignment of nanowires was attributed to the local balance and steady state of vapor flow at the substrate. The growth technique would be of particular interest for direct integration in the current silicon‐technology‐based optoelectronic devices.
Arrays of well‐aligned single‐crystal zinc oxide nanowires of uniform diameter and length have been synthesized on (100) silicon substrate via a simple horizontal double‐tube system (see Figure) using a chemical vapor transport and condensation method. The self‐alignment of the nanowires was attributed to the local balance and steady state of vapor flow at the substrate.
We analyze the mixing between Σ0 and Λ0 based on the baryon masses. We distinguish the contributions from QCD and QED in the baryon mass splittings. We find that the mixing angle between Σ0 and Λ0 is ...(2.07 ± 0.03) × 10−2, which leads to the decay branching fraction and up-down asymmetry of Λ+c → Σ0e + νeto be B (Λ+c → Σ0e + νe) = (1.5 ± 0.2) × 10−5 and α (Λ+c → Σ0e + νe) = − 0.86 ± 0.04 , respectively. Moreover, we obtain that ΔB ≡ B (Λ+c → Σ0 π+) − B (Λ+c → Σ+π0) = (3.8 ± 0.5) × 10−4 and Δα ≡ α(Λ+c → Σ0 π+) − α(Λ+c → Σ+π0) = (−1.6 ± 0.7) × 10−2, which should vanish without the mixing.
Solution culture experiments were conducted to investigate the effects of silicon (Si) on arsenate (As
V) uptake by rice. The addition of Si to the pretreatment or uptake solution significantly ...decreased shoot and root As concentrations (
P
<
0.001 and
P
<
0.05). The presence of Si in the pretreatment or uptake solution also significantly decreased shoot P concentrations (
P
<
0.001). The data demonstrated that both internal and external Si inhibited the uptake of As and P. Results of As uptake kinetics showed that the mechanism of the effect of Si on arsenate uptake is not caused by direct competition for active sites of transporters with As. The effect of Si on As uptake was not entirely mediated through the effect of Si on P uptake. Although the addition of Si to pretreatment solutions still significantly decreased shoot and root As concentrations, the extent of reduction became smaller when rice roots were coated with iron plaque.
Arsenate uptake by rice seedlings is affected by both Si (internal and external) and iron plaque on root surface.
(ProQuest: ... denotes formulae and/or non-USASCII text omitted) Though not considered in general, purely baryonic decays could shed light on the puzzle of the baryon number asymmetry in the universe ...by means of a better understanding of the baryonic nature of our matter world. As such, they constitute a yet unexplored class of decay processes worth investigating. We propose to search for purely baryonic decay processes at the LHCb experiment. No such type of decay has ever been observed. In particular, we concentrate on the decay ..., which is the simplest purely baryonic decay mode, with solely spin-1/2 baryons involved. We predict its decay branching ratio to be ... , which is sufficiently large to make the decay mode accessible to LHCb. Our study can be extended to other purely baryonic decays such as ..., as well as to similar decays of antitriplet b baryons such as ...
A new free-living marine nematode belonging to the genus Leptolaimus was discovered in the Bohai Sea, China, and is described here as Leptolaimus boucheri sp. nov. The new species is characterised by ...males having a papillary, four tubular and 15-21 alveolar precloacal supplements, females having only one tubular pre-anal supplement; cephalic sensilla very short and papilliform. The species can be distinguished from others of the genus by both males and females having precloacal or pre-anal supplements, and males with both tubular and alveolar precloacal supplements, females with only one tubular pre-anal supplement. An identification key for the group of Leptolaimus species characterised by the presence of both alveolar and tubular precloacal supplements is also given.
http://www.zoobank.org/urn:lsid:zoobank.org:pub:7D8CD22F-619C-4FE9-B147-5C38A6EAC3F3
The LHCb collaboration has presented first experimental evidence that spin-carrying matter and antimatter differ. The study looked at four-body decays of the Formula: see text baryon. Differences in ...the behaviour of matter and antimatter are associated with the non-invariance of fundamental interactions under the combined charge-conjugation and parity transformations, known as CP violation. We discuss purely baryonic decay processes, i.e. decay processes involving only spin-carrying particles. They are yet unexplored elementary processes. Their study opens a new chapter of flavour physics in the route towards a better understanding of CP violation. It may help us understand the observed matter and antimatter asymmetry of the Universe.
The relaxation spectrum of glassy solids has long been considered to probe their structural features and deformation mechanisms. Here, by systematically investigating the structural evolution, ...dynamical relaxations and mechanical properties of a Zr-based metallic glass subjected to different cryogenic treatment time, we build a bridge to connect the relaxation processes and mechanical properties. It is found that the β-relaxation triggered by local excitations has no memory effect of the thermal history or initial free volume content of the system. However, some local denser areas with a high potential energy created by CT might contribute to β′-relaxation that activated at a much lower energy, which may play a crucial important role in the fundamental deformation mechanisms of metallic glasses. The relaxation behaviors and the related improved mechanical properties can be rationalized in terms of the atomic-level stress theory. These findings will advance our understanding of the intrinsic correlation between local excitations and mechanical properties of metallic glasses, thereby may help guide to develop amorphous alloys with high mechanical performance.
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•Effect of cryogenic treatment on dynamical relaxations and mechanical properties were systematically investigated.•β-relaxation is independent of thermal history while β′-relaxation is enhanced with cryogenic treatment time.•A plausible atomic mechanism that correlates the relaxation processes and mechanical properties is proposed.
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