We report on the observation of new properties of secondary cosmic rays Li, Be, and B measured in the rigidity (momentum per unit charge) range 1.9 GV to 3.3 TV with a total of 5.4×10^{6} nuclei ...collected by AMS during the first five years of operation aboard the International Space Station. The Li and B fluxes have an identical rigidity dependence above 7 GV and all three fluxes have an identical rigidity dependence above 30 GV with the Li/Be flux ratio of 2.0±0.1. The three fluxes deviate from a single power law above 200 GV in an identical way. This behavior of secondary cosmic rays has also been observed in the AMS measurement of primary cosmic rays He, C, and O but the rigidity dependences of primary cosmic rays and of secondary cosmic rays are distinctly different. In particular, above 200 GV, the secondary cosmic rays harden more than the primary cosmic rays.
We report the observation of new properties of primary cosmic rays He, C, and O measured in the rigidity (momentum/charge) range 2 GV to 3 TV with 90×10^{6} helium, 8.4×10^{6} carbon, and 7.0×10^{6} ...oxygen nuclei collected by the Alpha Magnetic Spectrometer (AMS) during the first five years of operation. Above 60 GV, these three spectra have identical rigidity dependence. They all deviate from a single power law above 200 GV and harden in an identical way.
Using inelastic neutron scattering and molecular dynamics simulations on a model Zr-Cu-Al metallic glass, we show that transverse phonons persist well into the high-frequency regime, and can be ...detected at large momentum transfer. Furthermore, the apparent peak width of the transverse phonons was found to follow the static structure factor. The one-to-one correspondence, which was demonstrated for both Zr-Cu-Al metallic glass and a three-dimensional Lennard-Jones model glass, suggests a universal correlation between the phonon dynamics and the underlying disordered structure. This remarkable correlation, not found for longitudinal phonons, underscores the key role that transverse phonons hold for understanding the structure-dynamics relationship in disordered materials.
We report the first observation of the spontaneous polarization of Λ and Λover ¯ hyperons transverse to the production plane in e^{+}e^{-} annihilation, which is attributed to the effect arising from ...a polarizing fragmentation function. For inclusive Λ/Λover ¯ production, we also report results with subtracted feed-down contributions from Σ^{0} and charm. This measurement uses a dataset of 800.4 fb^{-1} collected by the Belle experiment at or near a center-of-mass energy of 10.58 GeV. We observe a significant polarization that rises with the fractional energy carried by the Λ/Λover ¯ hyperon.
With sufficient high cooling rates, a variety of liquids, including metallic melts, will cross a glass transition temperature and solidify into glass accompanying a marked increase of the shear ...viscosity in approximately 17 orders of magnitude. Because of the intricate atomic structure and dynamic behaviours of liquid, it is yet difficult to capture the underlying structural mechanism responsible for the marked slowing down during glass transition, which impedes deep understanding of the formation and nature of glasses. Here, we report that a universal structural indicator, the average degree of five-fold local symmetry, can well describe the slowdown dynamics during glass transition. A straightforward relationship between structural parameter and viscosity (or α-relaxation time) is introduced to connect the dynamic arrest and the underlying structural evolution. This finding would be helpful in understanding the long-standing challenges of glass transition mechanism in the structural perspective.
Face-centered-cubic (FCC) Fe40Mn20Cr20Ni20 high-entropy alloys (HEAs) with a weigh of 50 Kg were fabricated by industrialized vacuum-induction melting. This alloy consists of a tetragonal σ phase and ...minority M23C6 carbides embedded in the continuous FCC matrix after thermomechanical treatments. A heterogeneous structure composed of a phase distribution and grain size is formed. The yield strength and ultimate tensile strength are increased from 398 MPa to 679 MPa at 10−4 s−1 to 743 MPa and 1412 MPa at 3000 s−1, respectively. Meanwhile, the elongation is slightly improved as the strain rate rises. The strain rate sensitivity under quasi-static tension is 0.0172, in contrast to 0.3978 under dynamic deformation. Upon dynamic tension, the simultaneous enhancements of both strength and ductility are attributed to the joint activation of multiple strengthening mechanisms. Deformation-induced twinning further improves the strain-hardening ability of the alloy. Besides, short range order may seriously hinder the dislocation movement, especially when the thermal activation of dislocations gradually fails at high strain rates, which limit the dislocation slip to a smaller scale and result in deformed sub-grains. In contrast, under quasi-static tension, only dislocation slip dominates, accompanied by dislocation entanglement and massive pile-ups. Moreover, a typical Johnson-Cook model was employed to predict the dynamic-flow behavior. This study sheds lights on the mechanical performance superiority from heterogeneous HEAs under dynamic tension and might open new insights for developing high-performance HEAs to resist dynamic impacts.
•The Fe40Mn20Cr20Ni20 high-entropy alloys (HEAs) with a weigh of 50 Kg.•Heterphase and heterostructure induced by different phases and grain sizes.•The deformation twins and subgrains lead to higher strain-rate sensitivity under dynamic tension.•Stack fault energy was calculated from thermodynamics and molecular dynamics simulation.•Critical twin stress was determined for the target HEAs.
Ni3Al-based alloys were direct diffusion bonded to themselves at 950–1100 °C for 10–60min under a pressure of 20 MPa. The effects of the joining parameters on shear strength and interface bonding ...ratio of the direct diffusion bonded joints were studied in detail. The maximum joint strength achieved was 689 MPa, when the joint was bonded at 1100 °C for 60min under 20 MPa, corresponding to an interface bonding ratio of 95%. However, the fracture surface of the bonded joint was characterized mainly by cleavage fracture, indicating that the fracture mode was brittle rupture. The formation mechanism of the direct diffusion bonded joint and the coarsening phenomenon of γ’ precipitates in the Ni3Al-based alloy were revealed. To inhibit the coarsening of γ’ caused by high bonding temperature, a Ni interlayer was introduced. When bonded at 1050 °C with a 30 μm thick Ni foil, the pure Ni interlayer completely vanished because of interdiffusion with the Ni3Al-based alloy; however, the performance of the joint was still inferior to the base metal because of the heterogeneity in the microstructure of the diffusion zone. Therefore, the fracture occurred mainly at the diffusion zone. When bonded at 1050 °C with a 3 μm thick electroplated Ni coating, the microstructure of the diffusion zone was consistent with that of the base metal because of sufficient interdiffusion. The shear strength basically reached the level of the direct diffusion bonded joint at 1100 °C. The fracture morphology changed from cleavage fracture to alternating dimples and facets after introducing the electroplated Ni coating.
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•Direct diffusion bonding of Ni3Al-based alloys was carried out.•The formation mechanism of the direct diffusion bonded joint was revealed.•A Ni interlayer was introduced to reduce the bonding temperature.
Summary
Background
Inherited epidermodysplasia verruciformis (EV) is a rare skin disorder characterized by susceptibility to specific types of human papilloma virus (HPV) and is strongly associated ...with skin carcinomas. Inactivating mutations in EVER1/EVER2 account for most cases of EV. However, more phenotypes related to but distinct from EV have been reported with an immunodeficiency state but without EVER1/EVER2 mutation, and the genetic basis for these atypical EV cases is poorly understood.
Objectives
To identify the causative gene responsible for three siblings affected by atypical EV but without EVER1/EVER2 mutation.
Methods
Whole‐exome sequencing followed by Sanger sequencing was performed to identify the gene responsible for the patients with atypical EV enrolled in our study.
Results
A homozygous splicing mutation was detected in LCK (c.188‐2A>G). This mutation resulted in an exon 3 deletion T lymphocyte‐specific protein tyrosine kinase isoform, which further led to frameshift mutation and subsequent mRNA decay.
Conclusions
We demonstrate a novel mutation in LCK in a family affected by atypical EV with T‐cell defects, HPV infection and virus‐induced malignancy, providing new clues in the understanding of host defences against HPV and better genetic counselling of patients with the EV phenotype.
What's already known about this topic?
Epidermodysplasia verruciformis (EV) is an unusual genodermatosis characterized by an increased susceptibility to β‐human papillomavirus and is associated with a high risk of skin carcinoma.
Inactivating mutations in EVER1/EVER2 account for most cases of EV.
What does this study add?
Our study suggests an association between a novel splicing mutation in LCK and EV susceptibility.
What is the translational message?
Patients with EV should be tested for T lymphocyte‐specific protein tyrosine kinase deficiency and T‐cell function, which will help guide treatment.
Linked Comment: Uitto and Vahidnezhad. Br J Dermatol 2016; 175:1138–1139.
Hydrolysis of sodium borohydride (NaBH sub(4)) is one of the most attractive methods for energy generation of mobile systems used as hydrogen source because of the high gravimetric density and ...controllable hydrogen generation of NaBH sub(4). However, regeneration of NaBH sub(4) is a key issue that remains to be solved, and the energy efficiency of NaBH sub(4) is unknown. In the present study, the energy efficiency of NaBH sub(4) hydrolysis and the entire process of sodium metaborate (NaBO sub(2)) regeneration via reaction with magnesium hydride (MgH sub(2)) is determined through thermodynamics calculations. The maximum energy efficiency is 49.91%, indicating that NaBH sub(4) generation by reaction between MgH sub(2) and NaBO sub(2) during ball milling is feasible. An inexpensive high-energy ball milling method is employed to regenerate NaBH sub(4) by reaction of NaBO sub(2) with magnesium-lanthanum hydrides (H-Mg sub(3)La). Products after ball milling are characterized through Fourier transform infrared spectroscopy and X-ray diffraction measurements. In the reaction of NaBO sub(2) with H-Mg sub(3)La, MgH sub(2) reacts with NaBO sub(2) and then lanthanum hydride (LaH sub(3)) reacts with NaBO sub(2) to produce NaBH sub(4).
We study B --> K(*)l+l- decays (l = e, mu) based on a data sample of 657 x 10(6) BB pairs collected with the Belle detector at the KEKB e+e- collider. We report the differential branching fraction, ...isospin asymmetry, K* polarization, and the forward-backward asymmetry (A(FB)) as functions of q2 = M(ll)(2)c2. The fitted A(FB) spectrum exceeds the standard model expectation by 2.7 standard deviations. The measured branching fractions are B(B --> K*l+l-) = (10.7(-1.0)(+1.1) +/- 0.9) x 10(-7) and B(B --> Kl+l-) = (4.8(-0.4)(+0.5) +/- 0.3) x 10(-7), where the first errors are statistical and the second are systematic, with the muon to electron ratios R(K*) = 0.83 +/- 0.17 +/- 0.08 and R(K) = 1.03 +/- 0.19 +/- 0.06.
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