| 1. |
- Bassler, M, et al.
(författare)
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Beam line 1411 at MAX II - performance and first results
- 2001
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Ingår i: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT. - : ELSEVIER SCIENCE BV. - 0168-9002. ; 469:3, s. 382-393
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Tidskriftsartikel (refereegranskat)abstract
- We report on the characteristics and first results from the soft X-ray beam line I411, based on an undulator at the third generation synchrotron facility MAX II, Sweden. The beam line is designed for high-resolution, angle-resolved electron spectroscopy o
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| 2. |
- Bässler, M., et al.
(författare)
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Beam line I411 at MAX II - Performance and first results
- 2001
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0168-9002. ; 469:3, s. 382-393
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Tidskriftsartikel (refereegranskat)abstract
- We report on the characteristics and first results from the soft X-ray beam line I411, based on an undulator at the third generation synchrotron facility MAX II, Sweden. The beam line is designed for high-resolution, angle-resolved electron spectroscopy on gases, liquids and solids. Main components are the modified SX700 monochromator and the end station, both of which were previously used at beam line 51 at MAX I. The end station is equipped with a rotatable SES-200 hemispherical electron-analyser. Before the end station, a one-metre section is reserved for exchangeable experimental set-ups. The usable photon energy range is 50-1500 eV and the photon flux is two orders of magnitudes higher compared to beam line 51. At 400 eV a resolving power of about 5700 in the first order of the monochromator grating could be obtained. In gas phase, a total electron energy resolution of 16 meV has been achieved. Detailed results on the undulator performance, flux, photon and electron energy resolution as well as some technical details are presented here. As an example of the capabilities of the beam line I411, we present the fully vibrationally resolved Auger resonant Raman electron spectrum of gas-phase N 2.
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| 3. |
- Smedh, M., et al.
(författare)
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Vibrationally resolved C Is photoemission from CO absorbed on Rh(1 1 1) : The investigation of a new chemically shifted C Is component
- 2001
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Ingår i: Surface Science. - 0039-6028. ; 491:1-2, s. 99-114
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Tidskriftsartikel (refereegranskat)abstract
- High-resolution core-level photoemission at an energy resolution better than the intrinsic width of the C 1s level has been used to study the CO/Rh(1 1 1) overlayer system. C Is spectra have been measured in a large CO coverage range; from low coverages, where the CO molecules only adsorb in on-top positions, to saturation coverage, where CO molecules occupy both on-top and threefold hollow sites. Fine structure components due to vibrational excitation of the C-O stretch mode are clearly resolved in the emission peak from each site. The vibrational splittings and intensity ratios are found to be different for the different adsorption sites. A third C Is component, which has not been resolved earlier, is found at intermediate CO coverages. Some possible explanations for the origin of this extra component are discussed. In the light of its binding energy and vibrational energy in photoemission, together with supporting evidence from highresolution electron energy loss spectroscopy data and photoelectron diffraction, this is assigned to bridging CO species at intermediate coverages.
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| 4. |
- Andersen, J. N., et al.
(författare)
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Strong phonon replicas in Be 1s photoemission spectra
- 2001
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 86:19, s. 4398-4401
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Tidskriftsartikel (refereegranskat)abstract
- Strong phonon replicas in Be 1s photoemission spectra were investigated. The fine structure caused by intrinsic excitation of a narrow band of optical phonons was discussed in the 1s photoemission proces. The excitations of the optical Be phonons in the photoemission process caused fine structures. It was found that the phonon replicas in Be metal were strong due to large size misfit between neutral and core-ionized Be.
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| 5. |
- Beutler, A., et al.
(författare)
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Identification of a laterally mobile state during CO adsorption
- 2000
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Ingår i: Journal of Physics: Condensed Matter. - : IOP Publishing. - 0953-8984 .- 1361-648X. ; 12:6, s. 765-772
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Tidskriftsartikel (refereegranskat)abstract
- We have investigated CO adsorption at 300 K on ∼ 1.5 atomic layer thick Pd films on a Mo(110) surface by high-resolution core level photoemission. We describe how high-resolution core level spectroscopy may be utilized to study the influence of laterally mobile states on the sticking probability of molecules on such a laterally heterogeneous surface. The present Pd films are laterally heterogeneous in the sense that the additional ∼ 0.5 atomic Pd layer forms mesoscopic one-layer thick islands on top of the first Pd layer. At 300 K, CO chemisorbs on these two-layer thick islands but not on the one-layer parts of the film. The rate at which these two-layer islands are filled by CO molecules as the surface is exposed to CO is found to be consistent with a picture where CO molecules that initially impinge on the one-layer parts of the surface enter a laterally mobile state and diffuse to the two-layer islands and adsorb there. This mobile state is in many respects similar to a classical precursor state.
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| 6. |
- Both, C., et al.
(författare)
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Large-scale geographical variation confirms that climate change causes birds to lay earlier
- 2004
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Ingår i: Proceedings of the Royal Society of London Series B-Biological Sciences. - : The Royal Society. - 0962-8452 .- 1471-2954. ; 271:1549, s. 1657-1662
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Tidskriftsartikel (refereegranskat)abstract
- Advances in the phenology of organisms are often attributed to climate change, but alternatively, may reflect a publication bias towards advances and may be caused by environmental factors unrelated to climate change. Both factors are investigated using the breeding dates of 25 long-term studied populations of Ficedula flycatchers across Europe. Trends in spring temperature varied markedly between study sites, and across populations the advancement of laying date was stronger in areas where the spring temperatures increased more, giving support to the theory that climate change causally affects breeding date advancement.
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| 7. |
- Bökman, C.Fredrik, et al.
(författare)
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A Setup for the Coupling of a Thin-Layer Electrochemical Flow Cell to Electrospray Mass Spectrometry
- 2004
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Ingår i: Analytical Chemistry. ; 76:7, s. 2017-2024
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Tidskriftsartikel (refereegranskat)abstract
- A novel setup for the coupling of commercially available thin-layer cell to electrospray mass spectrometry (ESI-MS) which allows the elctrochemical reactions at the counter electrode to be straightforwardly separated from the flow into the mass spectrometer has been developed. In this way interferences from reaction products formed at the counter electrode can be minimized. This reduces the risk of changes in the mass spectra as a result of electrochemical reactions in the solution. The described setup also enables the working electrode to be positioned close to the electrospray (ESI) emitter without the need for a grounding point or a long transfer line between the electrochemical cell and the electrospray emitter. By decoupling the electrochemical reactions in the flow cell and those in the electrospray emitter, improved facilities for studies of electrochemical reactions are obtained through a better control of the potential of the working electrode. The setup has been used to study the oxidation of a drug (Olsalazine), which previously has been found to involve chemical follow-up reactions. It is also demonstrated that uncharged thiols can be detected in ESI-MS after spontaneous adsorption on a gold working electrode, followed by oxidative desorption to yield sulfinates or sulfonates. This adsorption and potential-controlled desorption has been used for the preconcentration of micromolar concentrations of 1-hexanethiol as well as for desalting of solutions containing micromolar concentrations of thiols. The results indicate that the present on-line coupling of an electrochemical cell to ESI-MS provides promising possibilities for sample preconcentration, matrix exchange (including desalting), and ionization of neutral compounds, such as thiols.
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| 8. |
- Hellerud, Christina, 1955, et al.
(författare)
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Glycerol metabolism and the determination of triglycerides--clinical, biochemical and molecular findings in six subjects.
- 2003
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Ingår i: Clinical chemistry and laboratory medicine : CCLM / FESCC. - 1434-6621. ; 41:1, s. 46-55
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Tidskriftsartikel (refereegranskat)abstract
- Recent recommendations in the National Cholesterol Education Program Expert Panel on Detection, Evaluation and Treatment of High Blood Cholesterol in Adults (ATPIII) are expected to increase the number of triglyceride (TG) determinations and consequently the risk of misinterpretation of "non-blanked" results with co-determination of free glycerol. Glycerol-kinase deficiency (GKD) is one cause of falsely elevated TG results. The natural history of isolated GKD with symptom-free cases and cases with e.g. severe episodes of hypoglycemia and/or ketoacidosis challenges the laboratories to identify cases of GKD and family members at risk. "Blanked" methods reporting both glycerol and TG concentration are therefore desirable. Molecular studies of the glycerol kinase (GK) and DAX1 genes were performed on four cases of "persistent hypertriglyceridemia" found in an Italian population and on two pediatric cases with high serum glycerol concentration. Two new missense mutations were found (C358Y, T961). Molecular modeling on GK from E. coli, indicate that these mutations are located in parts of the enzyme important for enzyme formation or activity. One splice-site mutation, (IVS9A-1G>A), was found in two brothers. Splice-junction analysis indicates that it destroys the splice site and results in a mixture of mRNA. Deletion of the GK and DAX1 genes was found in one child with symptoms of adrenal failure. A female with glycerolemia and glyceroluria had normal GK activity but possibly slightly decreased ability to oxidize glycerol.
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| 9. |
- Nyholm, R., et al.
(författare)
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Beamline I311 at MAX-LAB : A VUV/soft X-ray undulator beamline for high resolution electron spectroscopy
- 2001
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0168-9002. ; 467-468, s. 520-524
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Tidskriftsartikel (refereegranskat)abstract
- We describe a beamline based on a plane-grating monochromator and an end-station designed for high resolution photoemission and photoabsorption spectroscopy on surfaces and interfaces using undulator radiation in the energy range 30 1500 eV. The general design of the beamline is based on a horizontally focusing pre-mirror, an SX-700 type of plane-grating monochromator and re-focusing optics of Kirkpatrick-Baez design.
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| 10. |
- Smedh, M., et al.
(författare)
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Determination of the coverage dependent isosteric heat of adsorption of CO on Rh(1 1 1) by high resolution core level photoemission
- 2001
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Ingår i: Surface Science. - 0039-6028. ; 491:1-2, s. 115-123
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Tidskriftsartikel (refereegranskat)abstract
- High resolution core level photoemission is used to measure the equilibrium coverages of CO on Rh(1 1 1) at different sample temperatures and CO background pressures. Use of the chemical shifts of the C Is binding energy allows us to divide the total CO coverage into separate coverages for the different adsorption sites of CO on Rh(1 1 1). A Clausius-Clapeyron analysis of isosteres constructed from the measured isotherms for the total CO coverage is used to derive the coverage dependence of the isosteric heat of adsorption Eads for this adsorption system. The present results are found to agree well with a recent calculation of the adsorption energy for the Rh(1 1 1)-(2 × 2)-1CO structure at 0.25 ML (monolayer, ML). Furthermore, the present determination of Eads is consistent with a recent measurement of the zero coverage limit Eads(θ = θ ML) but is inconsistent with some previous determinations of this quantity. The coverage variation of the isosteric heat of adsorption is briefly discussed and put in relation to the relative occupations of different sites by the CO molecules.
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