A
bstract
Using data samples with an integrated luminosity of 6
.
4 fb
−
1
collected by the BESIII detector operating at the BEPCII storage ring, the process of
e
+
e
−
→
γϕJ/ψ
is studied. The ...processes of
e
+
e
−
→
ϕχ
c
1
,
c
2
,
χ
c
1
,
c
2
→
γJ/ψ
are observed with a significance of more than 10
σ
. The
s
-dependent cross section of
e
+
e
−
→
ϕχ
c
1
,
c
2
is measured between 4.600 and 4.951 GeV, and evidence of a resonance structure is found for the first time in the
ϕχ
c
2
process. We also search for the processes of
e
+
e
−
→
γX
(4140),
γX
(4274) and
γX
(4500) via the
γϕJ/ψ
final state, but no obvious structures are found. The upper limits on the production cross section times the branching fraction for these processes at the 90% confidence level are reported.
The human body louse, Pediculus humanus humanus, has one of the smallest insect genomes, containing ~10 775 annotated genes. Annotation of detoxification cytochrome P450 monooxygenase (P450), ...glutathione-S-transferase (GST), esterase (Est) and ATP-binding cassette transporter (ABC transporter) genes revealed that they are dramatically reduced in P. h. humanus compared to other insects except for Apis mellifera. There are 37 P450, 13 GST and 17 Est genes present in P. h. humanus, approximately half the number found in Drosophila melanogaster and Anopheles gambiae. The number of putatively functional ABC transporter genes in P. h. humanus and Ap. mellifera are the same (36) but both have fewer than An. gambiae (44) or Dr. melanogaster (65). The reduction of detoxification genes in P. h. humanus may be a result of this louse's simple life history, in which it does not encounter a wide variety of xenobiotics. Neuronal component genes are highly conserved across different insect species as expected because of their critical function. Although reduced in number, P. h. humanus still retains at least a minimum repertoire of genes known to confer metabolic or toxicokinetic resistance to xenobiotics (eg Cyp3 clade P450s, Delta GSTs, B clade Ests and B/C subfamily ABC transporters), suggestive of its high potential for resistance development.
By analyzing e(+)e(-) annihilation data with an integrated luminosity of 2.93 fb(-1) collected at the center-of-mass energy root s = 3.773 GeV with the BESIII detector, we present the first absolute ...measurements of the branching fractions of twenty Cabibbo-suppressed hadronic D0(+) decays involving multiple pions. The highest four branching fractions obtained are B(D-0 -> pi(+)pi(-)pi(0)) = (1.343 +/- 0.013(stat) +/- 0.016(syst))%, B(D-0 -> pi(+)pi(-)2 pi(0)) = (1.002 +/- 0.019(stat )+/- 0.024(syst))%, B(D-0 -> 2 pi(+)pi(-)pi(0))=(1.165 +/- 0.021(stat) +/- 0.021(sy)(st))%, and B(D+ -> 2 pi(+)pi(-)pi(0)). (1.074 +/- 0.040(stat) 0.030(syst))%. The CP asymmetries for the six decays with highest signal yields are also determined and found to be compatible with zero.
Abstract
This study treated the surface of ultra-high molecular weight polyethylene (UHMWPE) fibres with plasma and optimized the parameters of plasma treatment. On this basis, UHMWPE fibre ...composites reinforced with carbon nanotubes (CNTs) were prepared, and the changes of UHMWPE fibres before and after modification in the chemical composition, surface morphology, and mechanical properties were studied. The results showed that oxygen-containing functional groups and active free radicals on the surface of plasma treated UHMWPE fibres increased. Tensile strength and modulus of UHMWPE fibre composites reinforced with CNTs increased by 16.3% and 21%.
In this paper, the factors of safety and critical slip surfaces obtained by the limit equilibrium method (LEM) and two finite element methods (the enhanced limit strength method (ELSM) and strength ...reduction method (SRM)) are compared. Several representative two-dimensional slope examples are analysed. Using the associated flow rule, the results showed that the two finite element methods were generally in good agreement and that the LEM yielded a slightly lower factor of safety than the two finite element methods did. Moreover, a key condition regarding the stress field is shown to be necessary for ELSM analysis.
A bstract The $$ {D}_s^{+}\to {K}^{+}{K}^{-}{\mu}^{+}{\nu}_{\mu } $$ D s + → K + K − μ + ν μ decay is studied based on 7.33 fb − 1 of e + e − collision data collected with the BESIII detector at ...center-of-mass energies in the range from 4.128 to 4.226 GeV. The absolute branching fraction is measured as $$ \mathcal{B}\left({D}_s^{+}\to \phi {\mu}^{+}{\nu}_{\mu}\right)=\left(2.25\pm 0.09\pm 0.07\right)\times {10}^{-2} $$ B D s + → ϕ μ + ν μ = 2.25 ± 0.09 ± 0.07 × 10 − 2 , the most precise measurement to date. Combining with the world average of $$ \mathcal{B}\left({D}_s^{+}\to \phi {e}^{+}{\nu}_e\right) $$ B D s + → ϕ e + ν e , the ratio of the branching fractions obtained is $$ \frac{\mathcal{B}\left({D}_s^{+}\to \phi {\mu}^{+}{\nu}_{\mu}\right)}{\mathcal{B}\left({D}_s^{+}\to \phi {e}^{+}{\nu}_e\right)}=0.94\pm 0.08 $$ B D s + → ϕ μ + ν μ B D s + → ϕ e + ν e = 0.94 ± 0.08 , in agreement with lepton universality. By performing a partial wave analysis, the hadronic form factor ratios at q 2 = 0 are extracted, finding $$ {r}_V=\frac{V(0)}{A_1(0)}=1.58\pm 0.17\pm 0.02 $$ r V = V 0 A 1 0 = 1.58 ± 0.17 ± 0.02 and $$ {r}_2=\frac{A_2(0)}{A_1(0)}=0.71\pm 0.14\pm 0.02 $$ r 2 = A 2 0 A 1 0 = 0.71 ± 0.14 ± 0.02 , where the first uncertainties are statistical and the second are systematic. No significant S -wave contribution from f 0 (980) → K + K − is found. The upper limit $$ \mathcal{B}\left({D}_s^{+}\to {f}_0(980){\mu}^{+}{\nu}_{\mu}\right)\cdot \mathcal{B}\left({f}_0(980)\to {K}^{+}{K}^{-}\right)<5.45\times {10}^{-4} $$ B D s + → f 0 980 μ + ν μ ⋅ B f 0 980 → K + K − < 5.45 × 10 − 4 is set at 90% credibility level.
A bstract Using e + e − collision data collected at the BESIII detector at center-of-mass energies between 4.128 and 4.226 GeV, corresponding to an integrated luminosity of 7 . 33 fb − 1 , we ...determine the absolute branching fractions of fifteen hadronic $$ {D}_s^{+} $$ D s + decays with a double-tag technique. In particular, we make precise measurements of the branching fractions $$ \mathcal{B}\left({D}_s^{+}\to {K}^{+}{K}^{-}{\pi}^{+}\right)=\left(5.49\pm 0.04\pm 0.07\right)\% $$ B D s + → K + K − π + = 5.49 ± 0.04 ± 0.07 % , $$ \mathcal{B}\left({D}_s^{+}\to {K}_S^0{K}^{+}\right)=\left(1.50\pm 0.01\pm 0.01\right)\% $$ B D s + → K S 0 K + = 1.50 ± 0.01 ± 0.01 % and $$ \mathcal{B}\left({D}_s^{+}\to {K}^{+}{K}^{-}{\pi}^{+}{\pi}^0\right)=\left(5.50\pm 0.05\pm 0.11\right)\% $$ B D s + → K + K − π + π 0 = 5.50 ± 0.05 ± 0.11 % , where the first uncertainties are statistical and the second ones are systematic. The CP asymmetries in these decays are also measured and all are found to be compatible with zero.
Using a data sample of ${e}^{+}{e}^{{-}}$ collisions corresponding to an integrated luminosity of $567\text{ }\text{ }{\mathrm{pb}}^{{-}1}$ collected at a center-of-mass energy of $\sqrt{s}=4.6\text{ ...}\text{ }\mathrm{GeV}$ with the BESIII detector, we measure the absolute branching fraction of the inclusive semileptonic ${\mathrm{{\Lambda}}}_{c}^{+}$ decay with a double-tag method. We obtain $\mathcal{B}({\mathrm{{\Lambda}}}_{c}^{+}{\rightarrow}X{e}^{+}{{\nu}}_{e})=(3.95\pm{}0.34\pm{}0.09)%$, where the first uncertainty is statistical and the second systematic. Using the known ${\mathrm{{\Lambda}}}_{c}^{+}$ lifetime and the charge-averaged semileptonic decay width of nonstrange charmed mesons (${D}^{0}$ and ${D}^{+}$), we obtain the ratio of the inclusive semileptonic decay widths $\mathrm{{\Gamma}}({\mathrm{{\Lambda}}}_{c}^{+}{\rightarrow}X{e}^{+}{{\nu}}_{e})/\overline{\mathrm{{\Gamma}}}(D{\rightarrow}X{e}^{+}{{\nu}}_{e})=1.26\pm{}0.12$.
We prospectively investigated the diagnostic accuracy of contrast-free 3-dimensional time-of-flight magnetic resonance angiography (3D-TOF-MRA) with volume rendering (VR) at 3.0 T to detect ...intracranial aneurysms in a large cohort of patients.
We conducted a prospective clinical study including 411 patients with suspected aneurysms and other cerebral vascular diseases who were referred for contrast-free 3D-TOF-MRA at 3.0 T prior to digital subtraction angiography (DSA). 2D-DSA and VR-DSA were regarded as the gold standard. Forty-two patients were excluded. Accuracy, sensitivity, specificity, positive predictive values (PPV), and negative predictive values (NPV) as measures to detect or rule out intracranial aneurysms were determined by patient-, aneurysm-, vessel-, and aneurysm size-based evaluations.
In all 369 patients investigated, VR-DSA revealed 307 aneurysms in 246 patients (66.7%) and no aneurysm in 123 patients. The patient-based evaluation by VR 3D-TOF-MRA at 3.0 T yielded an accuracy of 97.6%, a sensitivity of 99.2%, specificity of 94.4%, PPV of 97.2%, and NPV of 98.3% in the detection of intracranial aneurysms. The aneurysm-based evaluation yielded an accuracy of 98.3%, sensitivity of 99.3%, specificity of 96.9%, PPV of 97.8%, and NPV of 99.1%. The vessel-based evaluation yielded accuracy of 98.8%, sensitivity of 99.2%, specificity of 98.5%, PPV of 97.5%, and NPV of 99.6%. The evaluation based on aneurysm sizes yielded similar results.
VR 3D-TOF-MRA at 3.0 T accurately identified the presence of intracranial aneurysms. High PPV and NPV indicated that VR 3D-TOF-MRA at 3.0 T may replace DSA as a contrast-free, noninvasive, and non-radiation-based modality for the diagnosis and screening of intracranial aneurysms.
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