| 1. |
- Ablikim, M., et al.
(författare)
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Measurements of (XcJ)-> K+K-K+K- decays
- 2006
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 642:3, s. 197-202
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Tidskriftsartikel (refereegranskat)abstract
- Using 14M psi(2S) events taken with the BESII detector, chi(cJ) -> 2(K+K-) decays are studied. For the four-kaon final state, the branching fractions are B(chi(c0,1,2) ->.2(K+K-)) = (3.48 +/- 0.23 +/- 0.47) x 10(-3), (0.70 +/- 0.13 +/- 0.10) x 10(-3), and (2.17 +/- 0.20 +/- 0.31) x 10(-3). For the phi K+K- final state, the branching fractions, which are measured for the first time, are B(chi(c0,1,2) -> phi K+K-) = (1.03 +/- 0.22 +/- 0.15) x 10(-3), (0.46 +/- 0.16 +/- 0.06) x 10(-3), and (1.67 +/- 0.26 +/- 0.24) x 10(-4). For the phi phi final state, B(chi(c0,2) -> phi phi) = (0.94 +/- 0.21 +/- 0.13) x 10(-3) and (1.70 +/- 0.30 +/- 0.25) x 10(-3).
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| 2. |
- Zhao, Y. S., et al.
(författare)
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Single crystalline submicrotubes from small organic molecules
- 2005
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Ingår i: Chemistry of Materials. - : American Chemical Society (ACS). - 0897-4756 .- 1520-5002. ; 17:25, s. 6430-6435
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Tidskriftsartikel (refereegranskat)abstract
- The single crystalline submicrotubes of a small organic functional molecule, 2,4,5-triphenylimidazole (TPI), were successfully prepared with a facile method. A series of characterizations indicated that the tubes were obtained from the rolling followed by seaming of a preorganized two-dimensional sheet-like structure, whose formation was due to the efficient cooperation of several molecular recognition elements. The length and diameter of the TPI tubes can be readily controlled by adjusting the experimental conditions. The as-prepared submicrotubes have intensive luminescence and size-dependent optical properties, which allows them to find potential applications in novel optical and optoelectronic devices together with their single crystalline structure and good stability. The strategy described here should give a useful enlightenment for the design and fabrication of tubular structures from small organic molecules.
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| 3. |
- Carninci, P, et al.
(författare)
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The transcriptional landscape of the mammalian genome
- 2005
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Ingår i: Science (New York, N.Y.). - : American Association for the Advancement of Science (AAAS). - 1095-9203 .- 0036-8075. ; 309:5740, s. 1559-1563
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Tidskriftsartikel (refereegranskat)abstract
- This study describes comprehensive polling of transcription start and termination sites and analysis of previously unidentified full-length complementary DNAs derived from the mouse genome. We identify the 5′ and 3′ boundaries of 181,047 transcripts with extensive variation in transcripts arising from alternative promoter usage, splicing, and polyadenylation. There are 16,247 new mouse protein-coding transcripts, including 5154 encoding previously unidentified proteins. Genomic mapping of the transcriptome reveals transcriptional forests, with overlapping transcription on both strands, separated by deserts in which few transcripts are observed. The data provide a comprehensive platform for the comparative analysis of mammalian transcriptional regulation in differentiation and development.
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| 4. |
- Liu, Y., et al.
(författare)
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Amorphous and nanocrystalline Al82Ni10Y8 alloy powder prepared by gas atomization
- 2005
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Ingår i: Intermetallics. - : Elsevier BV. - 0966-9795. ; 13:3-4, s. 393-398
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Tidskriftsartikel (refereegranskat)abstract
- An Al-10Ni-8Y (at.%) alloy was atomized by Ar gas and the morphology, microstructure, thermal stability, phase composition and microhardness of the as-atomized powder were investigated. Most of the powders are spherical in shape, but the surface morphology was different for powder of different size. The cross-section microstructure of powder with size below 15 Pro in diameter showed no detailed feature, indicating existence of amorphous phase or nanocrystalline structure. The as-atomized powder showed four distinct exothermic peaks when heated at 296, 340, 366 and 456 degrees C. The glass transition temperature T-g, crystallization temperature T-x, and the temperature interval of the supercooled liquid region Delta T-x(=T-x-T-g) were detected to be about 266, 288 and 22 degrees C. The Al82Ni10Y8 alloy powder exhibits a high Vickers hardness of 230.6, and shows great potential for structural application. (c) 2004 Elsevier Ltd. All rights reserved.
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| 5. |
- Liu, Y., et al.
(författare)
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Microstructural evolution of Al-Ni-Y powders an with different sizes
- 2005
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Ingår i: Zeitschrift fuer Metallkunde/Materials Research and Advanced Techniques. - 0044-3093. ; 96:1, s. 83-88
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Tidskriftsartikel (refereegranskat)abstract
- An Al-10Ni-8Y (at.%) alloy was atomized by Ar gas atomization in a close-coupled nozzle atomizer. The microstructure, phase composition, and thermal stability of the as-atomized powder were investigated by scanning electron microscopy, transmission electron microscopy, X-ray diffraction analysis and differential scanning calorimetry. Activation energies for different crystallization reactions were calculated using both Kissinger and Ozawa methods. The supercooled liquid region DeltaT(x) (= T(x) - T(g), where T(x) and T(g) are crystallization onset temperature and glass transition temperature, respectively) was detected to be in the range of 14-24 K. Also presented were attempts to determine the critical particle size for amorphous structure.
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| 6. |
- Yang, B., et al.
(författare)
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Fabrication and Characterization of Small Optical Ridge Waveguides Based on SU-8 Polymer
- 2009
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Ingår i: Journal of Lightwave Technology. - : Institute of Electrical and Electronics Engineers (IEEE). - 0733-8724 .- 1558-2213. ; 27:18, s. 4091-4096
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Tidskriftsartikel (refereegranskat)abstract
- Small SU-8 ridge optical waveguides with an air cladding and a SiO2 buffer on Si substrate have been realized by using a direct ultraviolet (UV) photolithography technology. The propagation loss measured by the cut-back method is about 0.1 dB/mm (@1550 nm) when the core width is 2.8 mu m. The bending losses of the present SU-8 optical ridge waveguides are also characterized. The measured results show that the bending loss decreases exponentially as the bending radius increases and the total loss can be reduced effectively by introducing an appropriate offset between two connected sections with different curvatures. A small bending radius (as small as 75 mu m) is still allowed for the requirement of a small bending loss (< 0.1 dB) when an offset of 0.1 mu m is introduced. Finally, by using this kind of waveguide, a small 1 x 2 Y-branch power splitter is fabricated and characterized.
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| 7. |
- Yang, L., et al.
(författare)
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Characteristic analysis of tapered lens fibers for light focusing and butt-coupling to a silicon rib waveguide
- 2009
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Ingår i: Applied Optics. - 1559-128X .- 2155-3165. ; 48:4, s. 672-678
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Tidskriftsartikel (refereegranskat)abstract
- The characteristics of tapered lens fibers (TLFs) are analyzed by using a finite-difference time-domain (FDTD) method. Two types of TLFs are considered, namely a tape red-cladding TLF and a tapered-core TLF The radial FDTD method is first used to simulate light focusing for these two types of TLFs. It is shown that the tapered-core TLF has a smaller focus spot size and a larger transmission loss than the tapered-cladding TLF. The butt-coupling between a TLF of either type and a Si rib waveguide is then simulated by a three-dimensional FDTD method. The tapered-core TLF has a smaller coupling loss to the Si rib waveguide but a similar total loss (the sum of the coupling loss and the transmission loss), as compared with the tapered-cladding TLF
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| 8. |
- Yang, L., et al.
(författare)
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Compact 2x2 tapered multimode interference couplers based on SU-8 polymer rectangular waveguides
- 2008
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 93:20
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Tidskriftsartikel (refereegranskat)abstract
- A 2x2 tapered multimode interference (MMI) coupler is designed and fabricated by using air-cladded SU-8 rectangular waveguide, which is effective in reducing the device size and improving the self-imaging quality. The parabolically tapered MMI section is used to reduce further the size of the MMI coupler. A compact 2x2 coupler with a total MMI size of about 5.3x34.2 mu m(2) is demonstrated and characterized. The measurement results show that the fabricated 2x2 MMI coupler has relatively small excess loss and nonuniformity for both polarizations in a broad wavelength range (from 1480 to 1630 nm).
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| 9. |
- Yu, Ling-Zhu, et al.
(författare)
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MEK1/2 regulates microtubule organization, spindle pole tethering and asymmetric division during mouse oocyte meiotic maturation.
- 2007
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Ingår i: Cell cycle (Georgetown, Tex.). - 1551-4005. ; 6:3, s. 330-8
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Tidskriftsartikel (refereegranskat)abstract
- It is well known that MAPK plays pivotal roles in oocyte maturation, but the function of MEK (MAPK kinase) remains unknown. We have studied the expression, subcellular localization and functional roles of MEK during meiotic maturation of mouse oocytes. Firstly, we found that MEK1/2 phoshorylation (p-MEK1/2, indicative of MEK activation) was low in GV (germinal vesicle) stage, increased 2h after GVBD (germinal vesicle breakdown), and reached the maximum at metaphase II. Secondly, we found that P-MEK1/2 was restricted in the GV prior to GVBD. In prometaphase I and metaphase I, P-MEK1/2 was mainly associated with the spindle, especially with the spindle poles. At anaphase I and telophase I, p-MEK1/2 became diffusely distributed in the region between the separating chromosomes, and then became associated with the midbody. The association of p-MEK1/2 with spindle poles was further confirmed by its colocalization with the centrosomal proteins, gamma-tubulin and NuMA. Thirdly, we have investigated the possible functional role of MEK1/2 activation by intravenous administration and intrabursal injection of a specific MEK inhibitor, U0126, and by microinjection of MEK siRNA into oocytes. All these manipulations cause disorganized spindle poles and spindle structure, misaligned chromosomes and larger than normal polar bodies. Our results suggest that MEK1/2 may function as a centrosomal protein and may have roles in microtubule organization, spindle pole tethering and asymmetric division during mouse oocyte maturation.
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