564 research outputs found
Impact of Cloud Longwave Scattering on Radiative Fluxes Associated With the MaddenâJulian Oscillation in the Indian Ocean and Maritime Continent
Previous studies suggested that cloud longwave radiation contributes to the development and maintenance of the MaddenâJulian Oscillation (MJO) and modelâbased convection is highly sensitive to the radiation scheme. However, currently used radiation schemes do not take cloud longwave scattering into account, resulting in an overestimation of the outgoing longwave radiation (OLR) and an underestimation of the downward longwave flux at the surface. We use combined active and passive satellite cloud property retrievals to quantify the oneâlayer cloud OLR and heating rate (HR) biases introduced by neglecting cloud longwave scattering in the Indian Ocean and Maritime Continent in the context of MJO, with a focus on its phases 3, 5, and 6. The results show that the satelliteâdetected oneâlayer cloud area consists primarily of ice clouds, particularly during the boreal winter in the 4âyear study period. An increased ice cloud area fraction of oneâlayer cloud groups is present up to 5Â days before the onset of MJO events. If longwave scattering is neglected, the composite mean OLR overestimation over the oneâlayer ice cloud area from 5Â days before to 4Â days after the MJO passage is approximately 3.5 to 5.0Â WÂ mâ2. Neglecting longwave scattering also leads to a HR underestimation at cloud base and an overestimation at cloud top, making the baseâtoâtop heating gradient less sharp at the cloudâresolving scale.Key PointsDuration of oneâlayer ice cloud coverage increases up to 5Â days before the MaddenâJulian Oscillation (MJO) passageNeglecting longwave scattering leads to a 3.5 to 5.0Â WÂ mâ2 overestimation of the outgoing longwave radiation (OLR)Neglecting longwave scattering leads to a less sharp heating gradient from cloud base to cloud topPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155944/1/jgrd56305_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155944/2/jgrd56305.pd
Multidifferential study of identified charged hadron distributions in -tagged jets in proton-proton collisions at 13 TeV
Jet fragmentation functions are measured for the first time in proton-proton
collisions for charged pions, kaons, and protons within jets recoiling against
a boson. The charged-hadron distributions are studied longitudinally and
transversely to the jet direction for jets with transverse momentum 20 GeV and in the pseudorapidity range . The
data sample was collected with the LHCb experiment at a center-of-mass energy
of 13 TeV, corresponding to an integrated luminosity of 1.64 fb. Triple
differential distributions as a function of the hadron longitudinal momentum
fraction, hadron transverse momentum, and jet transverse momentum are also
measured for the first time. This helps constrain transverse-momentum-dependent
fragmentation functions. Differences in the shapes and magnitudes of the
measured distributions for the different hadron species provide insights into
the hadronization process for jets predominantly initiated by light quarks.Comment: All figures and tables, along with machine-readable versions and any
supplementary material and additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-013.html (LHCb
public pages
Study of the decay
The decay is studied
in proton-proton collisions at a center-of-mass energy of TeV
using data corresponding to an integrated luminosity of 5
collected by the LHCb experiment. In the system, the
state observed at the BaBar and Belle experiments is
resolved into two narrower states, and ,
whose masses and widths are measured to be where the first uncertainties are statistical and the second
systematic. The results are consistent with a previous LHCb measurement using a
prompt sample. Evidence of a new
state is found with a local significance of , whose mass and width
are measured to be and , respectively. In addition, evidence of a new decay mode
is found with a significance of
. The relative branching fraction of with respect to the
decay is measured to be , where the first
uncertainty is statistical, the second systematic and the third originates from
the branching fractions of charm hadron decays.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-028.html (LHCb
public pages
Measurement of the ratios of branching fractions and
The ratios of branching fractions
and are measured, assuming isospin symmetry, using a
sample of proton-proton collision data corresponding to 3.0 fb of
integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The
tau lepton is identified in the decay mode
. The measured values are
and
, where the first uncertainty is
statistical and the second is systematic. The correlation between these
measurements is . Results are consistent with the current average
of these quantities and are at a combined 1.9 standard deviations from the
predictions based on lepton flavor universality in the Standard Model.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-039.html (LHCb
public pages
Measurement of CP asymmetries and branching fraction ratios of Bâ decays to two charm mesons
The asymmetries of seven decays to two charm mesons are measured using data corresponding to an integrated luminosity of of proton-proton collisions collected by the LHCb experiment. Decays involving a or meson are analysed by reconstructing only the or decay products. This paper presents the first measurement of and , and the most precise measurement of the other five asymmetries. There is no evidence of violation in any of the analysed decays. Additionally, two ratios between branching fractions of selected decays are measured.The CP asymmetries of seven B decays to two charm mesons are measured using data corresponding to an integrated luminosity of 9 fb of proton-proton collisions collected by the LHCb experiment. Decays involving a D or meson are analysed by reconstructing only the D or decay products. This paper presents the first measurement of (BâD) and (BâD), and the most precise measurement of the other five CP asymmetries. There is no evidence of CP violation in any of the analysed decays. Additionally, two ratios between branching fractions of selected decays are measured.[graphic not available: see fulltext]The asymmetries of seven decays to two charm mesons are measured using data corresponding to an integrated luminosity of of proton-proton collisions collected by the LHCb experiment. Decays involving a or meson are analysed by reconstructing only the or decay products. This paper presents the first measurement of and , and the most precise measurement of the other five asymmetries. There is no evidence of violation in any of the analysed decays. Additionally, two ratios between branching fractions of selected decays are measured
The improved Ocean Surface Albedo scheme (Version 1.0)
<p>For the paper: <i>Sensitivity of Arctic surface temperature to including a comprehensive ocean interior reflectance to the ocean surface albedo within the fully coupled CESM2</i></p><p>Code: the ocean surface albedo scheme. Version 1.0.</p>
Application of Electronic Nose for Rapid Detection of Off-flavour of Raw Pork
A method for the rapid identification of off-flavoured raw pork was investigated in this study as the off-flavoured raw pork often found in slaughtering and quarantine and brought the economic loss to the pork industry. The electronic nose (e-nose) was used to analyse the volatile compounds of normal and off-flavoured pork from two cuts (plum and hind legs) and principal component analysis (PCA), linear discriminant analysis (LDA) and random forest (RF) were combined to identify and classify the pork samples. It was also verified by headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS). The results showed that the PCA, LDA and RF models could effectively differentiate off-flavoured pork from normal pork by using e-nose detection. The test set of hind leg meat showed better classification accuracy than plum meat, which were 91% and 81% respectively. W1S, W5C, W3C, W1C and W2W were the key sensors in the e-nose detection. A total of 50 odour substances were detected by HS-GC-IMS, including 11 ketones, 10 aldehydes, 8 esters, 5 acids, 6 alcohols, 9 other substances (including sulphur and nitrogen containing substances) and 1 uncharacterised substance. Methyl acetate, 2-butanone, 2-hexanone, n-propanol, ethyl isovalerate, and 2-pentylfuran were identified as volatile markers to distinguish between normal and off-flavoured pork screened by using partial least squares discriminant analysis (PLS-DA). The results of the e-nose and HS-GC-IMS measurements were in good agreement, confirming that the e-nose technique could be used for identification and discrimination of off-flavoured raw pork, which would provide a technical reference for the rapid identification of off-flavoured raw pork
Isolation and Characterization of Sesquiterpenes from Celastrus orbiculatus and Their Antifungal Activities against Phytopathogenic Fungi
Celastrus orbiculatus is an insecticidal
plant belonging to the Celastraceae family. In this survey on the
secondary metabolites of plants for obtaining bioactive substances
to serve agriculture, the chemical constituents of the fruits of <i>C. orbiculatus</i> were investigated. This phytochemical investigation
resulted in the isolation of nine new and one known sesquiterpene.
Their structures, especially the complicated stereochemical features,
were elucidated on the basis of extensive NMR spectroscopic data analyses,
time-dependent density functional theory CD calculations, and the
CD exciton chirality method. Biological screenings disclosed that
these sesquiterpenes showed antifungal activities against six phytopathogenic
fungi. The results of our phytochemical investigation further disclosed
the chemical components of <i>C. orbiculatus</i>, and biological
screening implied that it may be potentially useful to protect crops
against phytopathogenic fungi and the bioactive compounds may be regarded
as candidate agents of antifungal agrochemicals for crop protection
products
Discovery and Mechanism Study of SARS-CoVâ2 3C-like Protease Inhibitors with a New Reactive Group
3CLpro is an attractive target for the treatment
of
COVID-19. Using the scaffold hopping strategy, we identified a potent
inhibitor of 3CLpro (3a) that contains a thiocyanate
moiety as a novel warhead that can form a covalent bond with Cys145
of the protein. Tandem mass spectrometry (MS/MS) and X-ray crystallography
confirmed the mechanism of covalent formation between 3a and the protein in its catalytic pocket. Moreover, several analogues
of compound 3a were designed and synthesized. Among them,
compound 3h shows the best inhibition of 3CLpro with an IC50 of 0.322 ÎŒM and a kinact/Ki value of 1669.34
Mâ1 sâ1, and it exhibits good
target selectivity for 3CLpro against host proteases. Compound 3c inhibits SARS-CoV-2 in Vero E6 cells (EC50 =
2.499 ÎŒM) with low cytotoxicity (CC50 > 200 ÎŒM).
These studies provide ideas and insights to explore and develop new
3CLpro inhibitors in the future
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