The synthesis and structural characterization of a series of supramolecular complexes of bicyclic cationic pyridine-fused 1,2,4-selenodiazoles with various anions is reported. The binding of ...trifluoroacetate, tetrachloroaurate, tetraphenylborate, perrhenate, and pertechnetate anions in the solid state is regarded. All the anions interact with selenodiazolium cations exclusively via a pair of “chelating” Se⋯O and H⋯O non-covalent interactions, which make them an attractive, novel, non-classical supramolecular recognition unit or a synthon. Trifluoroacetate salts were conveniently generated via novel oxidation reaction of 2,2′-dipyridyl diselenide with bis(trifluoroacetoxy)iodo)benzene in the presence of corresponding nitriles. Isolation and structural characterization of transient 2-pyridylselenyl trifluoroacetate was achieved. X-ray analysis has demonstrated that the latter forms dimers in the solid state featuring very short and strong Se⋯O and Se⋯N ChB contacts. 1,2,4-Selenodiazolium trifluoroacetates or halides show good solubility in water. In contrast, (AuCl4)−, (ReO4)−, or (TcO4)− derivatives immediately precipitate from aqueous solutions. Structural features of these supramolecular complexes in the solid state are discussed. The nature and energies of the non-covalent interactions in novel assembles were studied by the theoretical methods. To the best of our knowledge, this is the first study that regards perrhenate and pertechnetate as acceptors in ChB interactions. The results presented here will be useful for further developments in anion recognition and precipitation involving cationic 1,2,4-selenodiazoles.
A combined analysis of the current climate trends and the dynamics of soil respiration under soddy–weakly podzolic sandy-loamy soil (Entic Podzol (Arenic)) in the forest and meadow cenoses in the ...Prioksko-Terrasny Biosphere Reserve (southern part of the Moscow oblast) is performed. During the observation period (1998–2018), distinct trends of an increase in the average annual air temperature (
T
air
) and aridity of the summer season as well as a decrease in the duration of stable snow cover are observed. A general trend of a decrease in the total CO
2
fluxes from the Entic Podzol (Arenic) under a forest and a meadow for all seasons of the year and throughout the year is also observable on this background. The linear trends of a decrease in the annual and fall seasonal CO
2
fluxes from the soils in both cenoses are statistically significant (
P <
0.05). Over the 21-year observation period, the monthly average CO
2
fluxes from soils have tightly correlated with the average monthly
T
air
(
r
= 0.78–0.84,
P <
0.001). In dry years, the temperature sensitivity of soils expressed via the
Q
10
coefficient is by 10–12% lower, than in the years with normal moistening. The average long-term values of annual soil respiration (AnSR) in the forest and meadow cenoses amount to 581 ± 54 and 727 ± 71 g C/(m
2
year), respectively, with an interannual variation of 20–22%. The AnSR and summer hydrothermal coefficient are the most closely related explaining 51–56% of the variance in annual CO
2
fluxes from soils. The warm season (May–October), which coincides with the period of active plant vegetation, accounts for 73–77% of the AnSR. However, the share of the cold season (November–April) in the annual CO
2
flux from soils may reach 38–39% in individual years. Expansion of the network of stationary long-term year-round monitoring of soil respiration is a necessary condition for obtaining both more realistic estimates of the CO
2
fluxes from soils and predictions of the ecosystem responses to the current and future climate changes.
mcsanc is a Monte Carlo tool based on the SANC (Support for Analytic and Numeric Calculations for experiments at colliders) modules for higher order calculations in hadron collider physics. It allows ...to evaluate NLO QCD and EW cross sections for Drell–Yan processes (inclusive), associated Higgs and gauge boson production and single-top quark production in s- and t-channels. The paper contains theoretical description of the SANC approach, numerical validations and manual.
Program title: mcsanc-v1.01
Catalogue identifier: AEPO_v1_0
Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEPO_v1_0.html
Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland
Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html
No. of lines in distributed program, including test data, etc.: 144207
No. of bytes in distributed program, including test data, etc.: 1115648
Distribution format: tar.gz
Programming language: Fortran, C, C++.
Computer: x86(-64) architecture.
Operating system: Linux.
RAM: 2 GB
Classification: 11.1, 11.6.
External routines: LHAPDF 1. LoopTools 2, Cuba 3 (included in the distribution file).
Nature of problem:
Theoretical calculations at next-to-leading order in perturbation theory allow the computation of higher precision amplitudes for Standard Model processes and decays, provided proper treatments of UV divergences and IR singularities are performed.
Solution method:
Numerical integration of the precomputed differential expressions for partonic cross sections of certain processes implemented as SANC modules 4.
Restrictions:
The list of processes is limited to Drell–Yan, associated Higgs and gauge boson production and single-top production in s- and t-channels.
Running time:
From hours to days depending on the requested precision and kinematic conditions. The example provided takes approximately 10–15 min.
References:1M.R. Whalley, D. Bourilkov, and R.C. Group, hep-ph/05081102T. Hahn and M. Perez-Victoria, Comput. Phys. Commun. 118 (1999) 153–165, hep-ph/98075653T. Hahn, Comput. Phys. Commun. 168 (2005) 78–95, hep-ph/04040434A. Andonov, A. Arbuzov, D. Bardin, et al., Comput. Phys. Commun. 181 (2010) 305–312, arXiv:0812.4207
HERAFitter Alekhin, S.; Behnke, O.; Belov, P. ...
The European physical journal. C, Particles and fields,
07/2015, Letnik:
75, Številka:
7
Journal Article
Recenzirano
Odprti dostop
HERAFitter is an open-source package that provides a framework for the determination of the parton distribution functions (PDFs) of the proton and for many different kinds of analyses in Quantum ...Chromodynamics (QCD). It encodes results from a wide range of experimental measurements in lepton–proton deep inelastic scattering and proton–proton (proton–antiproton) collisions at hadron colliders. These are complemented with a variety of theoretical options for calculating PDF-dependent cross section predictions corresponding to the measurements. The framework covers a large number of the existing methods and schemes used for PDF determination. The data and theoretical predictions are brought together through numerous methodological options for carrying out PDF fits and plotting tools to help to visualise the results. While primarily based on the approach of collinear factorisation, HERAFitter also provides facilities for fits of dipole models and transverse-momentum dependent PDFs. The package can be used to study the impact of new precise measurements from hadron colliders. This paper describes the general structure of HERAFitter and its wide choice of options.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Our study of theoretical uncertainties for the four bosons processes at one-loop level including the case of the transverse polarization is presented. The calculations are based on helicity ...amplitudes approach for 4-boson SM interactions through a fermion and boson loops. The computation takes into account nonzero mass of loop particles. The obtained predictions are equally suitable for a wide range of energies and for arbitrary, including extreme, regions of the phase volume. Uncertainty estimates are received using the new Monte-Carlo tool SANCphot for γγ collision simulation with final states γγ, γZ, ZZ adapted for polarized γ beams.
Program Title: sancphot-v1.01
CPC Library link to program files:https://doi.org/10.17632/5sn9nywv2b.1
Licensing provisions: LGPL
Programming language: Fortran, C, C++
Nature of problem: Theoretical calculations at next-to-leading order in perturbation theory allow to compute higher precision amplitudes for Standard Model processes and decays, provided proper treatments of UV divergences and IR singularities are performed.
Solution method: Numerical integration of the precomputed differential expressions for polarized photon-photon cross sections of four-boson interaction processes implemented as SANC modules 1.
Additional comments including restrictions and unusual features: Uses subprograms Looptools 2, Cuba 3.
The list of processes is limited to photon-photon, photon-Z and Z-Z collisions.
The series of benzylic-substituted 1,2,4-selenodiazolium salts were prepared via cyclization reaction between 2-pyridylselenyl chlorides and nitriles and fully characterized. Substitution of the Cl ...anion by weakly binding anions promoted the formation supramolecular dimers featuring four center Se
N
chalcogen bonding and two antiparallel selenium⋯π interactions. Chalcogen bonding interactions were studied using density functional theory calculations, molecular electrostatic potential (MEP) surfaces, the quantum theory of atoms-in-molecules (QTAIM), and the noncovalent interaction (NCI) plot. The investigations revealed fundamental role of the selenium⋯π contacts that are stronger than the Se⋯N interactions in supramolecular dimers. Importantly, described herein, the benzylic substitution approach can be utilized for reliable supramolecular dimerization of selenodiazolium cations in the solid state, which can be employed in supramolecular engineering.
The method has been developed for calculating microhardness values under different loads, with known macro-hardness as well as with macro-hardness and microhardness with a single microhardness value, ...based on comparing the size of non-recovered and recovered imprints - imprints method (IM). The method correctness test for different materials in a wide range of hardness values -80 ... 1500 HV, at different indentation loads, was performed. High accuracy of the developed method is shown.
Categorization is the process by which objects are combined according to a certain principle, which provides more efficient and cost-effective information processing. One of the topical areas of ...research in this field is the study of the categorical effect in perceptual tasks, for example in the task visual search task. The present study investigated the effect of the role of category (basic or superordinate) on the time of guidance - the search for a target stimulus and verification - the time of identification of a target stimulus in a hybrid search task. Subjects had to find certain objects on the screen, which could be specified either as basic-level categories (e.g., cars) or superordinate-level categories (e.g., transport vehicles). An eye-tracking method was used to separate the entire hybrid search process into a guidance and a verification. A significant effect of category level was found on the rate of guidance, but not on the rate of verification.
Категоризация - процесс, в результате которого происходит объединение объектов по принципам экономии когнитивных ресурсов и валидных подсказок, что обеспечивает более эффективную обработку информации. Одним из актуальных направлений исследований в этой области является изучение эффекта превосходства категории базового уровня в перцептивных задачах, например, в задаче поиска объектов. В представленном исследовании изучалось влияние роли категории (базовой или суперординатной) на время гайденса- поиска целевого стимула и верификации - время идентификации целевого стимула в задаче гибридного поиска. Испытуемые должны были найти определенные объекты на экране, которые могли быть заданы либо как категории базового уровня (например, машины), либо как категории суперординатного уровня (например, транспортные средства). Для разделения всего процесса гибридного поиска на гайденс и верификацию использовался метод айтрекинга. Было обнаружено значимое влияние уровня категории на скорость гайденса, но не на скорость верификации.
This study is inspired by the potential of application-designed aluminium-copper conductors. This work combines recently discovered advantages of hybrids with one constituent having a helical ...architecture with the benefits provided by severe plastic deformation (SPD) methods. The hybrids are made by embedding copper helixes in melted aluminium and subjecting cast hybrid ingots to different SPD techniques. The electrical conductivity, microstructure features and strength of the produced samples are discussed in relation to effect of SPD and annealing on both constituents and an interface zone formed during the hybrids' production. It was shown that between all processing techniques the reciprocal extrusion (RE) has the great potential for production of lightweight conductors with high conductivity and enhanced strength. A new model describing the effective electrical conductivity of hybrid samples, consisting of an aluminium matrix with an embedded copper helix and intermetallic containing interface, is developed and justified by experimental data. The model is shown to be instrumental for analysis of the effect of the helix's parameters and interface width on effective conductivity of the hybrid samples and could be used for optimal design of hybrid conductors.
Display omitted
•The new design for AlCu conductor with copper used as helical wire fully embedded in the aluminium matrix is suggested.•Samples with helical reinforcement exhibit increased load-bearing capability and higher strain hardening during deformation.•The SPD processing is important for strengthening of the hybrid due to grain refinement and dissolution of intermetallic.•New analytical model predicting the electrical conductivity of hybrids and accounting for intermetallic layer is developed.•The model depends on two parameters determined by copper volume fraction and the geometry of the helical constituent.
Recent measurements of the
W
-boson charge asymmetry and of the
Z
-boson production cross sections, performed at the Tevatron collider in Run II by the D0 and CDF collaborations, are studied using ...the HERAFitter framework to assess their impact on the proton parton distribution functions (PDFs). The Tevatron measurements, together with deep-inelastic scattering data from HERA, are included in a QCD analysis performed at next-to-leading order, and compared to the predictions obtained using other PDF sets from different groups. Good agreement between measurements and theoretical predictions is observed. The Tevatron data provide significant constraints on the
d
-valence quark distribution.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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