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Institution

Paul Scherrer Institute

FacilityVilligen, Switzerland
About: Paul Scherrer Institute is a facility organization based out in Villigen, Switzerland. It is known for research contribution in the topics: Neutron & Large Hadron Collider. The organization has 9248 authors who have published 23984 publications receiving 890129 citations. The organization is also known as: PSI.


Papers
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Journal ArticleDOI
TL;DR: Modelling results support the findings that seasonal tree-ring δ(18) O variations are captured best when the week-to-week variations of the leaf water signal are suppressed, and suggest that climate signals in tree- ring δ-18 O variations should be strongest at temperate sites with humid conditions and precipitation maxima during the growing season.
Abstract: Summary � For accurate interpretation of oxygen isotopes in tree rings (d 18 O), it is necessary to disentangle the mechanisms underlying the variations in the tree’s internal water cycle and to understand the transfer of source versus leaf water d 18 O to phloem sugars and stem wood. � We studied the seasonal transfer of oxygen isotopes from precipitation and soil water through the xylem, needles and phloem to the tree rings of Larix decidua at two alpine sites in the L€ (Switzerland). Weekly resolved d 18 O records of precipitation, soil water, xylem and needle water, phloem organic matter and tree rings were developed. � Week-to-week variations in needle-water 18 O enrichment were strongly controlled by weather conditions during the growing season. These short-term variations were, however, not significantly fingerprinted in tree-ring d 18 O. Instead, seasonal trends in tree-ring d 18 O predominantly mirrored trends in the source water, including recent precipitation and soil water pools. Modelling results support these findings: seasonal tree-ring d 18 O variations are captured best when the week-to-week variations of the leaf water signal are suppressed. � Our results suggest that climate signals in tree-ring d 18 O variations should be strongest at temperate sites with humid conditions and precipitation maxima during the growing season.

176 citations

Journal ArticleDOI
TL;DR: Kapellasite, Cu3Zn(OH)6Cl2, a geometrically frustrated spin-1/2 kagome antiferromagnet polymorphic with herbertsmithite, is a gapless spin liquid showing unusual dynamic short-range correlations of noncoplanar cuboc2 type which persist down to 20 mK.
Abstract: Magnetic susceptibility, NMR, muon spin relaxation, and inelastic neutron scattering measurements show that kapellasite, Cu3Zn(OH)6Cl2, a geometrically frustrated spin-1/2 kagome antiferromagnet polymorphic with herbertsmithite, is a gapless spin liquid showing unusual dynamic short-range correlations of noncoplanar cuboc2 type which persist down to 20 mK. The Hamiltonian is determined from a fit of a high-temperature series expansion to bulk susceptibility data and possesses competing exchange interactions. The magnetic specific heat calculated from these exchange couplings is in good agreement with experiment. The temperature dependence of the magnetic structure factor and the muon relaxation rate are calculated in a Schwinger-boson approach and compared to experimental results.

176 citations

Journal ArticleDOI
TL;DR: In this article, the trends and variability of PM 10, PM 2.5 and PM coarse concentrations at seven urban and rural background stations in five European countries for the period between 1998 and 2010 were investigated.
Abstract: . The trends and variability of PM 10 , PM 2.5 and PM coarse concentrations at seven urban and rural background stations in five European countries for the period between 1998 and 2010 were investigated. Collocated or nearby PM measurements and meteorological observations were used in order to construct Generalized Additive Models, which model the effect of each meteorological variable on PM concentrations. In agreement with previous findings, the most important meteorological variables affecting PM concentrations were wind speed, wind direction, boundary layer depth, precipitation, temperature and number of consecutive days with synoptic weather patterns that favor high PM concentrations. Temperature has a negative relationship to PM 2.5 concentrations for low temperatures and a positive relationship for high temperatures. The stationary point of this relationship varies between 5 and 15 °C depending on the station. PM coarse concentrations increase for increasing temperatures almost throughout the temperature range. Wind speed has a monotonic relationship to PM 2.5 except for one station, which exhibits a stationary point. Considering PM coarse , concentrations tend to increase or stabilize for large wind speeds at most stations. It was also observed that at all stations except one, higher PM 2.5 concentrations occurred for east wind direction, compared to west wind direction. Meteorologically adjusted PM time series were produced by removing most of the PM variability due to meteorology. It was found that PM 10 and PM 2.5 concentrations decrease at most stations. The average trends of the raw and meteorologically adjusted data are −0.4 μg m −3 yr −1 for PM 10 and PM 2.5 size fractions. PM coarse have much smaller trends and after averaging over all stations, no significant trend was detected at the 95% level of confidence. It is suggested that decreasing PM coarse in addition to PM 2.5 can result in a faster decrease of PM 10 in the future. The trends of the 90th quantile of PM 10 and PM 2.5 concentrations were examined by quantile regression in order to detect long term changes in the occurrence of very large PM concentrations. The meteorologically adjusted trends of the 90th quantile were significantly larger (as an absolute value) on average over all stations (−0.6 μg m −3 yr −1 ).

175 citations

Journal ArticleDOI
TL;DR: In this paper, a thermal method for the determination of ambient organic carbon (OC) and elemental carbon (EC) concentrations in carbonaceous samples was further developed, which was applied to samples obtained with an aethalometer from an ongoing campaign at the high-alpine research station Jungfraujoch.

175 citations

Journal ArticleDOI
TL;DR: The difference between the anisotropic elastic free energies provides the fundamental explanation for the observed dominant occurrence of the a[100], as opposed to the a/2[111], Burgers vector configurations of prismatic dislocation loops in iron and iron-based alloys at high temperatures.
Abstract: Body-centered-cubic iron develops an elastic instability, driven by spin fluctuations, near the alpha-gamma phase transition temperature T(c) = 912 degrees C that is associated with the dramatic reduction of the shear stiffness constant c' (c(11)-c(12))/2 near T(c). This reduction of c' has a profound effect on the temperature dependence of the anisotropic elastic self-energies of dislocations in iron. It also affects the relative stability of the a[100] and a/2[111] prismatic edge dislocation loops formed during irradiation. The difference between the anisotropic elastic free energies provides the fundamental explanation for the observed dominant occurrence of the a[100], as opposed to the a/2[111], Burgers vector configurations of prismatic dislocation loops in iron and iron-based alloys at high temperatures.

175 citations


Authors

Showing all 9348 results

NameH-indexPapersCitations
Andrea Bocci1722402176461
Tobin J. Marks1591621111604
Wolfgang Wagner1562342123391
David D'Enterria1501592116210
Andreas Pfeiffer1491756131080
Christoph Grab1441359144174
Maurizio Pierini1431782104406
Alexander Belyaev1421895100796
Ajit Kumar Mohanty141112493062
Felicitas Pauss1411623104493
Chiara Mariotti141142698157
Luc Pape1411441130253
Rainer Wallny1411661105387
Roland Horisberger1391471100458
Emmanuelle Perez138155099016
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
202363
2022199
20211,299
20201,442
20191,330
20181,298