| 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. |
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| 3. |
- Kerzenmacher, T., et al.
(författare)
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Validation of NO2 and NO from the Atmospheric Chemistry Experiment (ACE)
- 2008
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Ingår i: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 8:19, s. 5801--5841-
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Tidskriftsartikel (refereegranskat)abstract
- Vertical profiles of NO2 and NO have been obtained from solar occultation measurements by the Atmospheric Chemistry Experiment (ACE), using an infrared Fourier Transform Spectrometer (ACE-FTS) and (for NO2) an ultraviolet-visible-near-infrared spectrometer, MAESTRO (Measurement of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation). In this paper, the quality of the ACE-FTS version 2.2 NO2 and NO and the MAESTRO version 1.2 NO2 data are assessed using other solar occultation measurements (HALOE, SAGE II, SAGE III, POAM III, SCIAMACHY), stellar occultation measurements (GOMOS), limb measurements (MIPAS, OSIRIS), nadir measurements (SCIAMACHY), balloon-borne measurements (SPIRALE, SAOZ) and ground-based measurements (UV-VIS, FTIR). Time differences between the comparison measurements were reduced using either a tight coincidence criterion, or where possible, chemical box models. ACE-FTS NO2 and NO and the MAESTRO NO2 are generally consistent with the correlative data. The ACE-FTS and MAESTRO NO2 volume mixing ratio (VMR) profiles agree with the profiles from other satellite data sets to within about 20% between 25 and 40 km, with the exception of MIPAS ESA (for ACE-FTS) and SAGE II (for ACE-FTS (sunrise) and MAESTRO) and suggest a negative bias between 23 and 40 km of about 10%. MAESTRO reports larger VMR values than the ACE-FTS. In comparisons with HALOE, ACE-FTS NO VMRs typically (on average) agree to ±8% from 22 to 64 km and to +10% from 93 to 105 km, with maxima of 21% and 36%, respectively. Partial column comparisons for NO2 show that there is quite good agreement between the ACE instruments and the FTIRs, with a mean difference of +7.3% for ACE-FTS and +12.8% for MAESTRO.
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| 4. |
- Carleer, M. R., et al.
(författare)
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Validation of water vapour profiles from the Atmospheric Chemistry Experiment (ACE)
- 2008
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Ingår i: Atmospheric Chemistry and Physics Discussion: An Interactive Open Access Journal of the European Geosciences Union. ; 8:2, s. 4499-4559
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Tidskriftsartikel (refereegranskat)abstract
- The Atmospheric Chemistry Experiment (ACE) mission was launched in August 2003 to sound the atmosphere by solar occultation. Water vapour (H2O), one of the most important molecules for climate and atmospheric chemistry, is one of the key species provided by the two principal instruments, the infrared Fourier Transform Spectrometer (ACE-FTS) and the MAESTRO UV-Visible spectrometer (ACE-MAESTRO). The first instrument performs measurements on several lines in the 1362–2137 cm−1 range, from which vertically resolved H2O concentration profiles are retrieved, from 7 to 90 km altitude. ACE-MAESTRO measures profiles using the water absorption band in the near infrared part of the spectrum at 926.0–969.7 nm. This paper presents a comprehensive validation of the ACE-FTS profiles. We have compared the H2O volume mixing ratio profiles with space-borne (SAGE II, HALOE, POAM III, MIPAS, SMR) observations and measurements from balloon-borne frostpoint hygrometers and a ground based lidar. We show that the ACE-FTS measurements provide H2O profiles with small retrieval uncertainties in the stratosphere (better than 5% from 15 to 70 km, gradually increasing above). The situation is unclear in the upper troposphere, due mainly to the high variability of the water vapour volume mixing ratio in this region. A new water vapour data product from the ACE-MAESTRO (Measurement of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation) is also presented and initial comparisons with ACE-FTS are discussed.
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| 5. |
- Peng, Ru, 1960-, et al.
(författare)
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Determination of Grain-Orientation-Dependent Stress in Coatings
- 2005
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Ingår i: Diffusion and defect data, solid state data. Part A, Defect and diffusion forum. - 1012-0386 .- 1662-9507. ; 105, s. 107-112
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Tidskriftsartikel (refereegranskat)abstract
- Quantitative interpretations of the so-called non-linear lattice strain distributions observed in coatings and thin films are important not only for determining the macro- and micro-stress fields, but also for inferring the active mechanisms of grain interactions during various deposition processes. In this paper, we present a method, which determines simultaneously both the macro- and micro-stress fields in the coatings and thin films. This method is extended from the previous stress-orientation distribution function (SODF) analysis method, which has already been used for residual stress analysis in bulk materials subjected to rolling and fatigue deformation. The validity of analysis method is demonstrated through measurements of lattice strains by high-energy x-ray and analysis of grain-orientation-dependent stresses in a CrN coating
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| 6. |
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| 7. |
- Yao, Mingguang, et al.
(författare)
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Synthesis of single-wall carbon nanotubes and long nanotube ribbons with Ho/Ni as catalyst by arc discharge
- 2005
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Ingår i: Carbon. - : Elsevier BV. - 0008-6223. ; 43:14, s. 2894-2901
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Tidskriftsartikel (refereegranskat)abstract
- The effect of a new bimetallic catalyst Ho/Ni for synthesis of single-walled carbon nanotubes (SWNTs) by arc discharge has been studied. Long ribbons consisting of roughly-aligned SWNT bundles were obtained by a modified arc discharge apparatus. Ribbon lengths can reach as much as 20 cm. Both elements Ho and Ni play important roles in the synthesis of SWNTs with high yield and purity. Changes in the Ho and Ni concentration in the catalyst hardly affect the diameter distribution of SWNTs, but the yield and purity of SWNTs are very sensitive to the concentration. An optimal range of Ho/Ni compositions for synthesis of SWNTs with relatively high purity and yield is given.
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| 8. |
- Evans, J D, et al.
(författare)
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Immune pathways and defence mechanisms in honey bees Apis mellifera.
- 2006
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Ingår i: Insect Mol Biol. - 0962-1075. ; 15:5, s. 645-56
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Tidskriftsartikel (refereegranskat)abstract
- Social insects are able to mount both group-level and individual defences against pathogens. Here we focus on individual defences, by presenting a genome-wide analysis of immunity in a social insect, the honey bee Apis mellifera. We present honey bee models for each of four signalling pathways associated with immunity, identifying plausible orthologues for nearly all predicted pathway members. When compared to the sequenced Drosophila and Anopheles genomes, honey bees possess roughly one-third as many genes in 17 gene families implicated in insect immunity. We suggest that an implied reduction in immune flexibility in bees reflects either the strength of social barriers to disease, or a tendency for bees to be attacked by a limited set of highly coevolved pathogens.
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| 9. |
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| 10. |
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| 11. |
- Li, J. S., et al.
(författare)
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A novel notch filter utilizing a composite right/left-handed transmission line
- 2006
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Ingår i: Microwave and optical technology letters (Print). - : Wiley. - 0895-2477 .- 1098-2760. ; 48:3, s. 626-628
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Tidskriftsartikel (refereegranskat)abstract
- A novel notch filter based on a composite right/left-handed (CRLH) transmission line is proposed. The proposed CRLH transmission line is different-from a conventional CRLH transmission line. The novel notch filter has a large notch depth, very small loss in the passband, and very sharp transitions at the two edges of the stop-band.
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| 12. |
- Li, Z. C., et al.
(författare)
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Synthesis of Sm-doped BaTiO3 ceramics and characterization of a secondary phase
- 2005
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Ingår i: Materials Science & Engineering. - : Elsevier BV. - 0921-5107 .- 1873-4944. ; 116:1, s. 34-39
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Tidskriftsartikel (refereegranskat)abstract
- Sm2O3-doped barium titanate ceramics with a positive temperature coefficient of resistivity (PTCR) were synthesized by solid-state reaction sintering. The electrical properties are related to the dopant content. The grain size decreases with increasing dopant content. Electron diffraction analysis revealed that a secondary phase with a space group of P6(3)22 and lattice parameters a = 10.6 Angstrom and c = 20.2 Angstrom formed in the ceramics.
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| 13. |
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| 14. |
- Oleynikov, P., et al.
(författare)
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Quantification of texture patterns
- 2006
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Ingår i: Electron Crystallography.. ; , s. 121-142
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 15. |
- Oleynikov, Peter, et al.
(författare)
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Structure of the pseudodecagonal Al–Co–Ni approximant PD4
- 2006
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Ingår i: Philosophical Magazine. - : Taylor and Francis. - 1478-6435 .- 1478-6443. ; 86:3-5, s. 457-462
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Tidskriftsartikel (refereegranskat)abstract
- A model for the pseudodecagonal approximant PD4 in the Al–Co–Ni system was deduced from single crystal X-ray diffraction data. The space group is Bbmm with a ?=?101.3, b ?=?32.1 and c ?=?4.1?Å. Atomic positions of 133 unique atoms in the unit cell with a reasonable geometry were found by direct methods and the difference Fourier syntheses. The obtained structure model is in good agreement with high-resolution electron microscopy images of PD4. Diffuse scattering observed along the a * direction in the hkl layers with l ?=?1/2, 3/2 etc. indicates a superstructure with a doubling of the periodicity along the c -axis and a lamellar disorder along the a -axis. If this diffuse scattering is taken into account, c ?=?8.2?Å.
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| 16. |
- Richards, Stephen, et al.
(författare)
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The genome of the model beetle and pest Tribolium castaneum.
- 2008
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Ingår i: Nature. - 1476-4687. ; 452:7190, s. 949-55
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Tidskriftsartikel (refereegranskat)abstract
- Tribolium castaneum is a representative of earth’s most numerous eukaryotic order, a powerful model organism for the study of generalized insect development, and also an important pest of stored agricultural products. We describe its genome sequence here. This omnivorous beetle has evolved an ability to interact with a diverse chemical environment as evidenced by large expansions in odorant and gustatory receptors, as well as p450 and other detoxification enzymes. Developmental patterns in Tribolium are more representative of other arthropods than those found in Drosophila, a fact represented in gene content and function. For one, Tribolium has retained more ancestral genes involved in cell-cell communication than Drosophila, and some are expressed in the growth zone crucial for axial elongation in short germ development. Systemic RNAi in T. castaneum appears to use mechanisms distinct from those found in C. elegans, but nevertheless offers similar power for the elucidation of gene function and identification of targets for selective insect control.
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| 17. |
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| 18. |
- Yun, Sang Ho, et al.
(författare)
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Self-assembled boron nanowire Y-junctions
- 2006
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Ingår i: Nano letters (Print). - : American Chemical Society (ACS). - 1530-6984 .- 1530-6992. ; 6:3, s. 385-389
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Tidskriftsartikel (refereegranskat)abstract
- In this work, we demonstrate that boron nanowire Y-junctions can be synthesized in a self-assembled manner by fusing two individual boron nanowires grown inclined toward each other. We show that the presence of a second liquid, in addition to the liquid Au catalyst, is critical to the inclination of the boron nanowire. The structure of the BNYJ arrays that we report here may allow construction of three- or multiple-terminal nanowire devices directly on Si-based readout circuits through controlled nanowire growth.
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| 19. |
- Zhang, Hongqiang, et al.
(författare)
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A structure model for τ(μ) phase in Al-Cr-Si alloys deduced from λ phase by the strong reflections approach
- 2006
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Ingår i: Acta Crystallographica Section B. - 0108-7681 .- 1600-5740. ; 62:1, s. 16-25
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Tidskriftsartikel (refereegranskat)abstract
- There are very obvious common features in the electron diffraction patterns of the λ and τ(μ) phases in the Al–Cr–Si system. The positions of the strong reflections and their intensity distributions are similar for the two structures. The relation of the reciprocal lattices of the λ and τ(μ) phases is studied. By applying the strong-reflections approach, the structure factors of τ(μ) are deduced from the corresponding structure factors of the known λ phase. Rules for selecting reflections for the strong-reflections approach are described. Similar to that of λ, the structure of τ(μ) contains six layers stacked along the c axis in each unit cell. There are 752 atoms in each unit cell, 53 of them are unique. The corresponding composition of the τ(μ) model is Al3.82 − xCrSix. Simulated electron diffraction patterns from the structure model are in good agreement with the experimental ones. The arrangement of interpenetrated icosahedral clusters in the τ(μ) phase is discussed.
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| 20. |
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| 21. |
- Zhang, H., et al.
(författare)
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Investigation of La9.33Si6O26 oxygen ionic conductor
- 2007
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Ingår i: Journal of Materials Science & Technology. - 1005-0302. ; 23:5, s. 629-632
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Tidskriftsartikel (refereegranskat)abstract
- La9.33Si6O26 oxygen ionic conductor was synthesized by solid state reaction method. Its structure was determined by single-crystal X-ray diffraction analysis at room temperature. The results showed that La9.33Si6O26 oxide has the apatite structure with space group P6(3)/m. AC impedance measurements indicated that the oxides sintered in nitrogen have much higher conductivity than those sintered in air. The effects of grain boundaries on the conductivity were discussed.
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| 22. |
- Zou, C.-D., et al.
(författare)
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Melting temperature depression of Sn-0.4Co-0.7Cu lead-free solder nanoparticles
- 2009
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Ingår i: Soldering and Surface Mount Technology. - : Emerald. - 1758-6836 .- 0954-0911. ; 21:2, s. 9-13
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Tidskriftsartikel (refereegranskat)abstract
- Purpose - The purpose of this paper is to study the melting temperature of the nanoparticles of the new developed Sn-0.4Co-0.7Cu (wt%) lead-free solder alloy.Design/methodology/approach - Nanoparticles of Sn-0.4Co-0.7Cu lead-free solder alloy were prepared by the self-developed consumable-electrode direct current arc technique, where ultrasonic vibration was applied during the manufacturing of the particles. X-ray diffraction and field emission scanning electron microscope were employed to analyze the crystal structure and morphology of the nanopartiles, respectively. Differential scanning calorimetry was used to investigate the melting temperature of both the bulk alloy and as-prepared nanoparticles.Findings - The melting temperature of the nanoparticles was approximately 5 degrees C lower compared to that of the bulk alloy.Originality/value - As a novel developed lead-free solder alloy, the Sn-0.4Co0.7Cu (wt%) alloy provides a cost advantage compared to the extensively used Sn-Ag-Cu system. Some limitations still exist, however, mainly due to its relatively higher melting temperature compared to that of eutectic Sn-37Pb solder. In view of this situation, the attempt to lower its melting temperature has recently attracted more attention based on the knowledge that the melting temperature for pure metals is reduced when the particle size is decreased down to a few tens of nanometers.
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| 23. |
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| 24. |
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| 25. |
- Zou, Y, et al.
(författare)
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Precision lifetime measurement of the 2p P-2(3/2) level for Li-like Ni by beam-foil spectroscopy
- 2005
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 235:1-4, s. 192-196
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Tidskriftsartikel (refereegranskat)abstract
- In this paper we present a precise and reliable measurement of the 1s(2)2p P-2(3/2) lifetime for Li-like Ni. The measurement was done using the technique of beam-foil spectroscopy employing a beam of 5.9 MeV/u Ni from the UNILAC accelerator at GSI. Special attention was taken concerning satellite blending and foil-ageing problems to justify the reliability of the lifetime value extracted from the measured decay curve. The experimental value for the 2p P-2(3/2) lifetime, 0.168 +/- 0.006 ns, is found to be in very good agreement with theoretical results.
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