| 1. |
- Ablikim, M., et al.
(författare)
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First measurement of e(+)e(-) -> pK(S)(0)(n)over-barK(-) + c.c. above open charm threshold
- 2018
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Ingår i: Physical Review D. - 2470-0010 .- 2470-0029. ; 98:3
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Tidskriftsartikel (refereegranskat)abstract
- The process e(+)e(-) -> pK(S)(0)(n) over barK(-) + c.c. and its intermediate processes are studied for the first time, using data samples collected with the BESIII detector at BEPCII at center-of-mass energies of 3.773, 4.008, 4.226, 4.258, 4.358, 4.416, and 4.600 GeV, with a total integrated luminosity of 7.4 fb(-1). The Born cross section of e(+)e(-) -> pK(S)(0)(n) over barK(-) + c.c. is measured at each center-of-mass energy, but no significant resonant structure in the measured cross-section line shape between 3.773 and 4.600 GeV is observed. No evident structure is detected in the pK(-), nK(S)(0), pK(S)(0), nK(+), p (n) over bar, or (KSK-)-K-0 invariant mass distributions except for Lambda(1520). The Born cross sections of e(+)e(-) -> Lambda(1520)(n) over barK(S)(0) + c.c. and e(+)e(-) -> Lambda(1520)(p) over barK(+) + c.c. are measured, and the 90% confidence level upper limits on the Born cross sections of e(+)e(-) -> Lambda(1520)(Lambda) over bar (1520) are determined at the seven center-of-mass energies. There is an evident difference in line shape and magnitude of the measured cross sections between e(+)e(-) -> Lambda(1520)(-> pK(-))(n) over barK(S)(0) and e(+)e(-) -> pK-(Lambda) over bar (1520)(-> (n) over barK(S)(0)).
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| 2. |
- Ablikim, M., et al.
(författare)
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Observation of psi(3686) -> eta ' e(+)e(-)
- 2018
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Ingår i: Physics Letters B. - : ELSEVIER SCIENCE BV. - 0370-2693 .- 1873-2445. ; 783, s. 452-458
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Tidskriftsartikel (refereegranskat)abstract
- Using a data sample of 448.1 x 10(6) psi(3686) events collected with the BESIII detector at the BEPCII collider, we report the first observation of the electromagnetic Dalitz decay psi(3686) -> eta'e(+)e(-), with significances of 7.0 sigma and 6.3 sigma when reconstructing the eta' meson via its decay modes eta' -> gamma pi(+)pi(-) and eta' -> pi(+)pi(-) eta (eta -> gamma gamma), respectively. The weighted average branching fraction is determined to be B(psi(3686) -> eta'e(+)e(-)) = (1.90 +/- 0.25 +/- 0.11) x 10(-6), where the first uncertainty is statistical and the second systematic.
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| 3. |
- Ablikim, M., et al.
(författare)
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Observation of the Semileptonic Decay D-0 -> a(0)(980)(-)e(+)nu(e) and Evidence for D+ -> a(0)(980)(0)e(+)nu(e)
- 2018
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Ingår i: Physical Review Letters. - : AMER PHYSICAL SOC. - 0031-9007 .- 1079-7114. ; 121:8
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Tidskriftsartikel (refereegranskat)abstract
- Using an e(+)e(-) collision data sample of 2.93 fb(-1) collected at a center-of-mass energy of 3.773 GeV by the BESIII detector at BEPCII, we report the observation of D-0 -> a(0)(980)(-)e(+)nu(e) and evidence for D+ -> a(0)(980)(0)e(+)nu(e) with significances of 6.4 sigma and 2.9 sigma, respectively. The absolute branching fractions are determined to be B(D-0 -> a(0)(980)(-)e(+)nu(e)) x B(a(0)(980)(-) -> eta pi(-)) = [1.33(-0.29)(+0.33)(stat) +/- 0.09(syst)] x 10(-4) and B(D+ -> a(0)(980)(0)e(+)nu(e)) x B(a(0)(980)(0) -> eta pi(0)) = [1.66(-0.66)(+0.81)(stat) +/- 0.11(syst) x 10(-4). This is the first time the a(0)(980) meson has been measured in a D-0 semileptonic decay, which would open one more interesting page in the investigation of the nature of the puzzling a(0)(980) states.
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| 4. |
- Ablikim, M., et al.
(författare)
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Search for invisible decays of omega and phi with J/psi data at BESIII
- 2018
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Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 98:3
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Tidskriftsartikel (refereegranskat)abstract
- Using a data sample of (1310.6 +/- 7.0) x 10(6) J/psi events collected with the BESIII detector operating at the BEPCII collider, we perform the first experimental search for invisible decays of a light vector meson (V = omega, phi) via J/psi -> V-eta decays. The decay of eta -> pi(+)pi(-)pi(0) is utilized to tag the V meson decaying into the invisible final state. No evidence for a significant invisible signal is observed, and the upper limits on the ratio of branching fractions at the 90% confidence level are determined to be B(omega -> invisible)/B(omega -> pi(+)pi(-)pi(0)) < 8.1 x 10(-5) and B(phi -> invisible)/B(phi -> K+K-) < 3.4 x 10(-4). By using the world average values of B(omega -> pi(+)pi(-)pi(0) and B(phi -> K+K-,) the upper limits on the decay branching fractions at the 90% confidence level are set as B(omega -> invisible) < 7.3 x 10(-5) and B(phi -> invisible) < 1.7 x 10(-4), respectively.
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| 5. |
- Ablikim, M., et al.
(författare)
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Search for the rare decays D -> h(h((')))e(+) e(-)
- 2018
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Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 97:7
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Tidskriftsartikel (refereegranskat)abstract
- We search for rare decays of D mesons to hadrons accompanied by an electron-positron pair (h(h((')))e(+)e(- )),using an e(+)e(-) collision sample corresponding to an integrated luminosity of 2.93 fb(-1) collected with the BESIII detector at root s = 3.773 GeV. No significant signals are observed, and the corresponding upper limits on the branching fractions at the 90% confidence level are determined. The sensitivities of the results are at the level of 10(-5)-10(-6), providing a large improvement over previous searches.
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| 6. |
- Cui, Luqing, et al.
(författare)
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A new approach for determining GND and SSD densities based on indentation size effect : An application to additive-manufactured Hastelloy X
- 2022
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Ingår i: Journal of Materials Science & Technology. - : Elsevier. - 1005-0302. ; 96, s. 295-307
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Tidskriftsartikel (refereegranskat)abstract
- Dislocation plays a crucial role in controlling the strength and plasticity of bulk materials. However, determining the densities of geometrically necessary dislocations (GNDs) and statistically stored dislocations (SSDs) is one of the classical problems in material research for several decades. Here, we proposed a new approach based on indentation size effect (ISE) and strengthening theories. This approach was performed on a laser powder bed fused (L-PBF) Hastelloy X (HX), and the results were verified by the Hough-based EBSD and modified Williamson–Hall (m-WH) methods. Furthermore, to better understand the new approach and essential mechanisms, an in-depth investigation of the microstructure was conducted. The distribution of dislocations shows a clear grain orientation-dependent: low density in large <101> preferentially orientated grains while high density in fine <001> orientated grains. The increment of strengthening in L-PBF HX is attributed to a huge amount of edge-GNDs. Planar slip is the main operative deformation mechanism during indentation tests, and the slip step patterns depend mostly on grain orientations and stacking fault energy. This study provides quantitative results of GND and SSD density for L-PBF HX, which constructs a firm basis for future quantitative work on other metals with different crystal structures.
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| 7. |
- Cui, Luqing, et al.
(författare)
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Cyclic Response of Additive Manufactured 316L Stainless Steel : The Role of Cell Structures
- 2021
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Ingår i: Scripta Materialia. - : Elsevier. - 1359-6462 .- 1872-8456. ; 205
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Tidskriftsartikel (refereegranskat)abstract
- We report the effect of cell structures on the fatigue behavior of additively manufactured (AM) 316L stainless steel (316LSS). Compared with the cell-free samples, the fatigue process of fully cellular samples only consists of steady and overload stages, without an initial softening stage. Moreover, the fully cellular sample possesses higher strength, lower cyclic softening rate and longer lifetime. Microscopic analyses show no difference in grain orientations, dimensions, and shapes. However, the fully cellular samples show planar dislocation structures, whereas the cell-free samples display wavy dislocation structures. The existence of cell structures promotes the activation of planar slip, delays strain localization, and ultimately enhances the fatigue performance of AM 316LSS.
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| 8. |
- Li, Ning, et al.
(författare)
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Revealing genes associated with cervical cancer in distinct immune cells : A comprehensive Mendelian randomization analysis
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Ingår i: International Journal of Cancer. - 0020-7136.
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Tidskriftsartikel (refereegranskat)abstract
- Human papillomavirus can be contracted by sexually active women. However, only a small proportion of these infections persist and have the potential to progress into cervical cancers, indicating a significant involvement of the immune system in cervical cancer development. Despite this, our understanding of the precise contributions of genes from different immune cell types in cervical cancers remains limited. Therefore, the primary objective of our study was to investigate the potential causal relationships between specific immune cell genes and the development of cervical cancers. By accessing expression quantitative trait loci datasets of 14 distinct immune cell types and genome wide association study of cervical cancers, we employed the summary data-based Mendelian randomization (SMR) along with multi-single nucleotide polymorphism (SNP)-based SMR to identify significant genes associated with cervical cancers. Colocalization analysis was further conducted to explore the shared genetic causality. A total of 10 genes across 11 immune cell types (26 significant gene-trait associations) were found to be associated with cervical cancers after false discovery rate correction. Notably, the ORMDL3, BRK1 and HMGN1 gene expression levels showed significant association with cervical cancer in specific immune cell types, respectively. These associations were supported by strong evidence of colocalization analyses. Our study has identified several genes in different immune cells that were associated with cervical cancer. However, further research is necessary to confirm these findings and provide more comprehensive insights into the association between these gene expressions and cervical cancer risk.
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| 9. |
- Shi, Yu, et al.
(författare)
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A Suzuki-type cross-coupling reaction of arylacetylene halides with arylboronic acids
- 2011
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Ingår i: Applied organometallic chemistry. - : Wiley. - 0268-2605 .- 1099-0739. ; 25:7, s. 514-520
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Tidskriftsartikel (refereegranskat)abstract
- A PdCl(2)-catalyzed direct alkynylation of arylboronic acids to give diarylacetylenes is described. The optimal conditions using PdCl(2) as catalyst, MeOH-PhMe-H(2)O as solvent and K(2)CO(3) as base effectively suppressed the formation of homo-coupling product and afforded moderate to good yield of the desired unsymmetrical coupling product. This reaction represents a Suzuki-type sp(2)(C-B)-sp(C-X) cross-coupling.
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| 10. |
- Shi, Yu, et al.
(författare)
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PdCl2-catalyzed cross-coupling reaction of arylacetylene iodides with arylboronic acids to diarylacetylenes
- 2010
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Ingår i: Tetrahedron Letters. - : Elsevier BV. - 0040-4039 .- 1359-8562. ; 51:28, s. 3626-3628
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Tidskriftsartikel (refereegranskat)abstract
- Anew Suzuki-type cross-coupling reaction between 1-iodo-2-arylalkynes and arylboronic acids to afford a wide variety of functionalized diarylacetylenes in a mild reaction condition was developed. The reaction was catalyzed by a small amount of a structurally simple, commercially available, and stable PdCl2. This unique sp-sp(2) carbon-carbon bond formation provides a new protocol for the synthesis of diarylacetylenes, which is a new addition to the Suzuki cross-coupling reaction. (C) 2010 Elsevier Ltd. All rights reserved.
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