Using (10087±44)×10^{6} J/ψ events collected with the BESIII detector, numerous Ξ^{-} and Λ decay asymmetry parameters are simultaneously determined from the process J/ψ→Ξ^{-}Ξover ...¯^{+}→Λ(pπ^{-})π^{-}Λover ¯(nover ¯π^{0})π^{+} and its charge-conjugate channel. The precisions of α_{Λ0} for Λ→nπ^{0} and αover ¯_{Λ0} for Λover ¯→nover ¯π^{0} compared to world averages are improved by factors of 4 and 1.7, respectively. The ratio of decay asymmetry parameters of Λ→nπ^{0} to that of Λ→pπ^{-}, ⟨α_{Λ0}⟩/⟨α_{Λ-}⟩, is determined to be 0.873±0.012_{-0.010}^{+0.011}, where the first and the second uncertainties are statistical and systematic, respectively. The ratio is smaller than unity more than 5σ, which signifies the existence of the ΔI=3/2 transition in Λ for the first time. Besides, we test for CP symmetry in Ξ^{-}→Λπ^{-} and in Λ→nπ^{0} with the best precision to date.
The quantum entangled J/ψ→Σ^{+}Σover ¯^{-} pairs from (1.0087±0.0044)×10^{10} J/ψ events taken by the BESIII detector are used to study the nonleptonic two-body weak decays Σ^{+}→nπ^{+} and Σover ...¯^{-}→nover ¯π^{-}. The CP-odd weak decay parameters of the decays Σ^{+}→nπ^{+} (α_{+}) and Σover ¯^{-}→nover ¯π^{-} (αover ¯_{-}) are determined to be 0.0481±0.0031_{stat}±0.0019_{syst} and -0.0565±0.0047_{stat}±0.0022_{syst}, respectively. The decay parameter αover ¯_{-} is measured for the first time, and the accuracy of α_{+} is improved by a factor of 4 compared to the previous results. The simultaneously determined decay parameters allow the first precision CP symmetry test for any hyperon decay with a neutron in the final state with the measurement of A_{CP}=(α_{+}+αover ¯_{-})/(α_{+}-αover ¯_{-})=-0.080±0.052_{stat}±0.028_{syst}. Assuming CP conservation, the average decay parameter is determined as ⟨α_{+}⟩=(α_{+}-αover ¯_{-})/2=-0.0506±0.0026_{stat}±0.0019_{syst}, while the ratios α_{+}/α_{0} and αover ¯_{-}/αover ¯_{0} are -0.0490±0.0032_{stat}±0.0021_{syst} and -0.0571±0.0053_{stat}±0.0032_{syst}, where α_{0} and αover ¯_{0} are the decay parameters of the decays Σ^{+}→pπ^{0} and Σover ¯^{-}→pover ¯π^{0}, respectively.
Optical beam steerers on InP integrated photonics have not been able to offer high angular resolution, due to the technological challenges in realizing a large emission aperture. In this paper, we ...propose the creation of waveguide-based grating antennas fabricated in SiO 2 super-cladding on InP membrane on silicon (IMOS) to achieve simultaneously high resolution and good compatibility with InP-based active devices. By exploiting the high dry etch selectivity between SiO 2 and InP, a tolerant fabrication process is proposed and demonstrated, allowing for high controllability in the process. Device parameters including buffer thickness and pitch have been explored to obtain an optimized design. A 2-mm long grating antenna is fabricated and shows a record narrow full-width-half-maximum angular beam width of 0.05° and a high spatial resolution of more than 250 points when the wavelength is tuned over a range of 100 nm.
The factor associated suicide (Fas) and its ligand (FasL) signaling is an important regulatory pathway of apoptosis in mammalian follicles. However, whether apoptosis in bovine oocytes is regulated ...by the Fas–FasL signaling pathway remains unknown. In this study, localization of Fas and FasL in immature oocytes and FasL in cumulus cells were examined using immunofluorescence staining. In addition, exogenous FasL was added to an in vitro culture system to investigate apoptotic changes in bovine oocytes, using annexin-V and terminal uridine nick-end labeling staining, and real-time quantitative polymerase chain reaction. In this study, Fas was expressed in immature oocytes, whereas FasL was expressed in cumulus cells, but not in immature oocytes; annexin–V- and terminal uridine nick-end labeling-positive rates of oocytes treated with 2, 10, or 50 ng/mL FasL were higher than those of control oocytes (P < 0.05); and oocytes from the three treatment groups had higher expression levels of Fas and B cell lymphoma/leukemia-2 associated X than those in the control group (P < 0.05). Taken together, we concluded that the Fas–FasL signaling pathway was involved in regulation of bovine oocyte apoptosis, perhaps related to B cell lymphoma/leukemia-2 associated X upregulation.
A
bstract
Using 1310
.
6 × 10
6
J/ψ
and 448
.
1 × 10
6
ψ
(3686) events collected with the BESIII detector, the branching fractions of
J/ψ
decays to Σ
+
Σ
¯
−
is measured to be (10
.
61 ± 0
.
04 ± 0
.
...36) × 10
−
4
, which is significantly more precise than the current world average. The branching fractions of
ψ
(3686) decays to Σ
+
Σ
¯
−
is measured to be (2
.
52 ± 0
.
04 ± 0
.
09) × 10
−
4
, which is consistent with the previous measurements. In addition, the ratio of
B
(
ψ
(3686) → Σ
+
Σ
¯
−
)
/
B
(
J/ψ
→ Σ
+
Σ
¯
−
) is determined to be (23
.
8 ± 1
.
1)% which violates the “12% rule”.
A
bstract
By using 6.32 fb
−
1
of data collected with the BESIII detector at center-of-mass energies between 4.178 and 4.226 GeV, we perform an amplitude analysis of the decay
D
s
+
→
K
S
0
π
+
π
0
...and determine the relative fractions and phase differences of different intermediate processes, which include
K
S
0
ρ
(770)
+
,
K
S
0
ρ
(1450)
+
,
K
*
(892)
0
π
+
,
K
*
(892)
+
π
0
, and
K
*
(1410)
0
π
+
. With the detection efficiency based on the amplitude analysis results, the absolute branching fraction is measured to be
ℬ
D
s
+
→
K
S
0
π
+
π
0
=
5.43
±
0.30
stat
±
0.15
syst
×
10
−
3
.
•Behaviour for a range of rock masses taking into account blast-induced damage is analysed.•Blast-induced damage to the rock mass in ground reaction curve construction is included.•Practical ...guidelines for the preliminary design phase for an excavation resulting from blasting are provided.
Using the convergence-confinement curves methodology, we analysed excavation behaviour for a range of rock masses of different geotechnical qualities, taking into account blast-induced damage. The novelty of the research is (i) we include blast-induced damage to the rock mass in ground reaction curve construction, and (ii) we analyse results for 54 rock mass and rock geotechnical quality scenarios. The research, an application of a previously developed methodology (González-Cao et al., 2013), provides practical guidelines for the preliminary design phase for an excavation resulting from blasting. Our main conclusions are (i) that rock mass quality has a greater bearing on the plastic radius and excavation maximum displacement than blast-induced damage, and (ii) that the plastic radius and maximum displacement around an excavation increase with the level of blast-induced damage, most especially for poor quality rock masses. This would justify the need to limit blast-induced damage in poor quality rock masses.
The kinetics of the thermal degradation of polymethylphenylsiloxane containing methacryloyl groups (PMPS-M) were investigated by thermogravimetric analysis (TGA). Thermal degradation of PMPS-M had ...two different processes: “unzipping degradation” and “rearrangement degradation”. The corresponding kinetic parameters of the two degradation stages were determined by using Friedman and Flynn–Wall–Ozawa methods, respectively. Coats–Redfern and Phadnis–Deshpande methods were also used to discuss the probable degradation mechanisms of the two different stages. The results showed that the activation energy obtained from Friedman method was in good agreement with the value obtained using Flynn–Wall–Ozawa method. The solid-state decomposition mechanism followed by the first degradation stage of PMPS-M was a decelerated D
4 type (three-dimensional diffusion controlled reaction). However, as for the second degradation stage of PMPS-M, its solid-state decomposition mechanism corresponded to a sigmoidal A
3 type, a nucleation and growth mechanism.
A new Al-Mg-0.15% Sc-0.10% Zr (wt%) alloy sheet with an average (sub)grain size of ~2.25µm was processed by a simple thermomechanical processing. Excellent superplastic (elongations of ≥800%) can be ...achieved at a temperature range of 450–500°C and a high strain rate range of 1×10−2–1×10−1s−1. A maximum elongation of ~1579% was obtained at 475°C and a high strain rate of 5×10−2s−1. Electron back scatter diffraction analysis and transmission electron microscopy results showed that superior superplastic ductility of the Al-Mg-Sc-Zr alloy can be ascribed to the complete transformation of low angle grain boundaries to high angle grain boundaries due to the occurrence of continuous dynamic recrystallization and the presence of stable coherent Al3ScxZr1−x particles that effectively impede the growth of the grains during superplastic deformation. Besides, strong β-fiber rolling textures gradually weakened, and random textures were predominant in the superplastic deformed alloy. Analyses on the superplastic data revealed that the average strain rate sensitivity parameter and the average activation energy of the Al-Mg-Sc-Zr alloy were ~0.48 and ~84.4kJ/mol–1, respectively. All results indicated that the main superplastic deformation mechanism was grain boundary sliding.
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