Bulgarian Academy of Sciences

About: Bulgarian Academy of Sciences is a government organization based out in Sofia, Bulgaria. It is known for research contribution in the topics: Catalysis & Coupling constant. The organization has 17989 authors who have published 36276 publications receiving 642820 citations. The organization is also known as: Bulgarian Academy of Sciences，簡稱：BAS & Balgarska Akademiya na Naukite.

Search for electroweak production of charginos and neutralinos in multilepton final states in proton-proton collisions at √s=13 TeV

Abstract: Results are presented from a search for the direct electroweak production of charginos and neutralinos in signatures with either two or more leptons (electrons or muons) of the same electric charge, or with three or more leptons, which can include up to two hadronically decaying tau leptons. The results are based on a sample of proton-proton collision data collected at $ \sqrt{s}=13 $ TeV, recorded with the CMS detector at the LHC, corresponding to an integrated luminosity of 35.9 fb$^{−1}$. The observed event yields are consistent with the expectations based on the standard model. The results are interpreted in simplified models of supersymmetry describing various scenarios for the production and decay of charginos and neutralinos. Depending on the model parameters chosen, mass values between 180 GeV and 1150 GeV are excluded at 95% CL. These results significantly extend the parameter space probed for these particles in searches at the LHC. In addition, results are presented in a form suitable for alternative theoretical interpretations.

Single-polymer dynamics under constraints: scaling theory and computer experiment

Abstract: The relaxation, diffusion and translocation dynamics of single linear polymer chains in confinement is briefly reviewed with emphasis on the comparison between theoretical scaling predictions and observations from experiment or, most frequently, from computer simulations. Besides cylindrical, spherical and slit-like constraints, related problems such as the chain dynamics in a random medium and the translocation dynamics through a nanopore are also considered. Another particular kind of confinement is imposed by polymer adsorption on attractive surfaces or selective interfaces—a short overview of single-chain dynamics is also contained in this survey. While both theory and numerical experiments consider predominantly coarse-grained models of self-avoiding linear chain molecules with typically Rouse dynamics, we also note some recent studies which examine the impact of hydrodynamic interactions on polymer dynamics in confinement. In all of the aforementioned cases we focus mainly on the consequences of imposed geometric restrictions on single-chain dynamics and try to check our degree of understanding by assessing the agreement between theoretical predictions and observations.

Measurement of differential top-quark-pair production cross sections in pp collisions at √s = 7TeV

Abstract: Normalised differential top-quark pair production cross sections are measured in pp collisions at a centre-of-mass energy of 7 TeV at the LHC with the CMS detector using data recorded in 2011 corresponding to an integrated luminosity of 5.0 inverse femtobarns. The measurements are performed in the lepton+jets decay channels (e+jets and mu+jets) and the dilepton decay channels (oppositely charged ee, mu mu, and e mu). The t t-bar differential cross section is measured as a function of kinematic properties of the final-state charged leptons and jets associated to b quarks, as well as those of the top quarks and the t t-bar system. The data are compared with several predictions from perturbative QCD calculations up to approximate next-to-next-to-leading-order precision. No significant deviations from the standard model are observed.

Structure and redox properties of MnOx/Yttrium-stabilized zirconia (YSZ) catalyst and its used in CO and CH4 oxidation

Abstract: The complex structure, the redox properties, and the catalytic activity for the MnO x /yttrium-stabilized zirconia (YSZ) catalytic system were explored and reported here The MnO x /YSZ material (10% by wt as MnO 2 ) was characterized by temperature-programmed reduction (TPR), X-ray diffraction (XRD) and FITR spectroscopy of low-temperature CO adsorption The redox properties were explored by exposing the material to H 2 -rich/O 2 -rich environment cycles, at various temperatures (up to 1173 K), followed by material characterization The catalytic activity of the MnO x /YSZ system in CO and CH 4 oxidation (fuel rich/lean) was investigated and correlated with the observed structure and redox properties XRD data indicated that MnO x is well dispersed on the YSZ support, with crystallites below 2–3 nm (close to the XRD detection limit) TPR data show that most of the Mn is present as Mn 3+ and Mn 2+ Low-temperature CO adsorption on MnO x /YSZ shows the formation of Mn 3+ –CO species (2180 cm −1 ) which are easily desorbed by evacuation at 85 K Heating the sample (120 K and up) in CO atmosphere shows the formation of CO 2 and bridged or bidentate carbonates which block the CO adsorption sites At higher temperatures, the CO 3 2− species are mostly converted into HCO 3 − species When CO is adsorbed at 85 K on a sample exposed to a H 2 -rich atmosphere, Mn 2+ –CO species are formed Heating the sample in CO atmosphere (O-rich) leads again to oxidation of CO In this case no CO 2 is formed, but at ∼130 K monodentate carbonates start to emerge Catalytic activity results indicate that the MnO x presence favored the CO oxidation process but had an inhibiting effect on the CH 4 oxidation The kinetic experiments showed that for CO oxidation, the rate is first order in O 2 on MnO x /YSZ catalyst and zero order on the YSZ support

The terminology of larval cestodes or metacestodes

Abstract: The terminology associated with the nomenclature of larval or metacestodes is reviewed as well as the various morphological and developmental characters used to define different types of larval cestodes. Based on a review of the literature, the key characters differentiating the types of larval cestodes are the presence of a primary lacuna and the invagination/retraction of the scolex. The presence of a cercomer and of a bladder-like enlargement of the larval cestode were considered to be useful secondary characteristics. Using these characters, six basic types of larval cestodes were identified: the procercoid, an alacunate form which cannot develop further until ingested by a second intermediate host; the plerocercus, an alacunate form with a retracted scolex; the plerocercoid, an alacunate form with an everted scolex; the merocercoid, an alacunate form with an invaginated scolex; the cysticercoid, a lacunate form with a retracted scolex; and the cysticercus, a lacunate form with an invaginated scolex. The diversity of larval types within the broad classifications of cysticercoid and cysticercus can be differentiated by the use of appropriate prefixes. Deficiencies in knowledge of specific types of larval cestodes are identified and further avenues of research are indicated.