53,432 research outputs found
Osiadanie terenu i jego wpływ na środowisko w chińskich regionach Xu Zhou, Yan Zhou oraz Huainan i Huaibei
No full textThe main coal mining subsidence area of the Xu Zhou, Yan Zhou, Huaihe collapsed state region were investigated including the environment state, water surface area, pollution source, and the utilization state. Some advice wasproposed to protect the environment of the subsidence area.Badaniem objęto główną strefę osiadania w stanie całkowitego zawału w chińskich regionach Xu Zhou, Yan Zhou i Huaihe, w tym stan otoczenia, wody powierzchniowe, źródła zanieczyszczenia oraz utylizację. Zaproponowano kilka rozwiązań dla ochrony środowiska strefy osiadania
Measurement of the differential and double-differential Drell-Yan cross sections in proton-proton collisions at root s=7 TeV
No full textMeasurements of the differential and double-differential Drell-Yan cross sections are presented using an integrated luminosity of 4.5 (4.8) fb−1 in the dimuon (dielectron) channel of proton-proton collision data recorded with the CMS detector at the LHC at s√ = 7 TeV. The measured inclusive cross section in the Z-peak region (60–120 GeV) is σ(ℓℓ) = 986.4 ± 0.6 (stat.) ± 5.9 (exp. syst.) ± 21.7 (th. syst.) ± 21.7 (lum.) pb for the combination of the dimuon and dielectron channels. Differential cross sections dσ/dm for the dimuon, dielectron, and combined channels are measured in the mass range 15 to 1500 GeV and corrected to the full phase space. Results are also presented for the measurement of the double-differential cross section d2σ/dm d|y| in the dimuon channel over the mass range 20 to 1500 GeV and absolute dimuon rapidity from 0 to 2.4. These measurements are compared to the predictions of perturbative QCD calculations at next-to-leading and next-to-next-to-leading orders using various sets of parton distribution functions
Drell–Yan processes with WINHAC
No full textWe present the Monte Carlo event generator WINHAC for Drell–Yan processes in proton–proton, proton–antiproton, proton–ion and ion–ion collisions. It features multiphoton radiation within the Yennie–Frautschi–Suura exclusive exponentiation scheme with electroweak corrections for the charged-current processes and multiphoton radiation generated by PHOTOS for neutral-current ones. For the initial-state QCD/QED parton shower and hadronisation, it is interfaced with PYTHIA. It includes several options, e.g. for the polarized W-boson production, generation of weighted/unweighted events, etc. WINHAC was cross-checked numerically at the per-mille level with independent Monte Carlo programs, such as HORACE and SANC. It has been used as a basic tool for developing and testing some new methods of precise measurements of the Standard Model parameters at the LHC, in particular the W-boson mass. Recently, it has been applied to simulations of the double Drell–Yan processes resulting from double-parton scattering, in order to assess their influence on the Higgs-boson detection at the LHC in its ZZ and decay channels
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Test of structure functions using lepton pairs: W-charge asymmetry and Drell-Yan production at CDF
No full textThe charge asymmetry of leptons from W-bosons and the Drell-Yan cross section of massive charged lepton pairs from {gamma}*/Z-bosons produced in p{anti p} collisions are measured using 110 pb{sup -1} of collisions taken by the Collider Detector at Fermilab (CDF) during 1992-95. The W-asymmetry measurement provides a precise constraint of the slope of the quark distribution ratio, d(x)/u(x), over the x range of 0.006 to 0.34. The Drell-Yan measurement spans the mass range of 11 to 500 GeV/c{sup 2}, and QCD calculations using recent parton distribution functions are in good agreement with it
The environment and the utilization the status of the subsidence area in the Xu Zhou, Yan Zhou and Huainan and Huaibei region of China
No full textTyt. z nagł.Pozostali autorzy artykułu: Jiaping Yan, Shun Wang, Shuxian, Ruan.Bibliogr. s. [133].Badaniem objęto główną strefę osiadania w stanie całkowitego zawału w chińskich regionach Xu Zhou, Yan Zhou i Huaihe, w tym stan otoczenia, wody powierzchniowe, źródła zanieczyszczenia oraz utylizację. Zaproponowano kilka rozwiązań dla ochrony środowiska strefy osiadania.The main coal mining subsidence area of the Xu Zhou, Yan Zhou, Huaihe collapsed state region were investigated including the environment state, water surface area, pollution source, and the utilization state. Some advice wasproposed to protect the environment of the subsidence area.Dostępny również w formie drukowanej.SŁOWA KLUCZOWE: obniżenie poziomu wód, stan zasobów wodnych, utylizacja. KEYWORDS: coal mine subsidence waters, water resources status, utilization
Using performance assessment in secondary school mathematics: an empirical study in a Singapore classroom
No full textThis article reports an exploratory study on using performance assessment in mathematics instruction in a high-performing secondary school in Singapore. An intact mathematics class participated in the study, and received chapter-based performance tasks as intervention during regular mathematics lessons for about one and a half school years. The performance tasks used included authentic and/or open-ended tasks. The students’ academic achievements and attitudes in mathematics were compared with a comparison class that did not receive the intervention. Both quantitative and qualitative data were collected, mainly through questionnaire surveys, performance task tests, conventional school exams, and interviews with students and teachers. The results suggest that the students receiving the intervention performed significantly better than their counterparts in solving conventional exam problems, and in general they also showed more positive changes in attitudes towards mathematics and mathematics learning. The students from the experimental class also expressed positive views about the benefits of using performance tasks in promoting their ability in higher order thinking, though no statistically significant difference was detected between the two classes of students in solving unconventional tasks before and after intervention. Overall, the results appear to support teachers’ using contextualised problems in real life situations and open-ended investigations in students’ learning of mathematic
Measurement of the Differential Production Cross Section of W Bosons and Charge Asymmetry at �s = 7 TeV with the ATLAS Detector
No full textThis document presents a measurement of the production cross section of W
bosons and of its charge asymmetry in proton-proton collisions at a centre of mass energy of 7 TeV with the ATLAS detector. These measurements provide information on the momentum fraction of the protons carried by the partons contributing to the W production and therefore allow to better understand the parton distribution functions of the proton.
The W candidate events are selected in the W�enu decay mode. The LAr electromagnetic calorimeter plays an important role in the detection of electrons and the author has worked on the on-line energy reconstruction in the LAr detectors. A subject which is treated in some detail is the evaluation of the charge misidentification rates for electrons and positrons. This is a key ingredient for charge related measurements such as the W charge asymmetry.
In this document, the W production cross section times the branching ratio is studied inclusively, as a function of the lepton pseudorapidity and as a double differential measurement as a function of the lepton pseudorapidity and transverse energy. The charge asymmetry measurement is presented as a function of the lepton pseudorapidity and as a double differential measurement as well. The data were recorded by the ATLAS detector in 2011 and correspond to 4.7 fb�1
Gated relational stacked denoising autoencoder with localized author embedding for global citation recommendation
No full textCitation recommendation is an effective and efficient way to facilitate authors finding desired references. This paper presents a novel neural network based model, called gated relational probabilistic stacked denoising autoencoder with localized author (GRSLA) embedding, for global citation recommendation task. Our model is comprised of two modules with different neural network architecture. For each citing and cited papers, we use a gated paper embedding module, which is extended from probabilistic stacked denoising autoencoder (PSDAE) by adding gated units, to obtain their paper vectors. The added gated units are able to utilize text information of cited paper to refine the vector representation of citing paper in multiple semantic levels. For an author in papers, we first apply topic model to obtain his/her semantic neighbors, and then use a localized author embedding (LAE) module to excavate author vector representation from semantic and explicit neighbors. Unlike most graph convolutional network (GCN) based methods, the LAE module is able to avoid computing global Laplacian in whole graph by taking limited neighbors. Moreover, the LAE module can also be stacked to absorb more neighbors, which makes our model have high extendibility. Based on the generation process of GRSLA, we also derive a learning algorithm of our model by maximum a posteriori (MAP) estimation. We conduct experiments on the AAN, DBLP and CORD-19 datasets, and the results show that GRSLA model works well than previous global citation recommendation methods
Differential measurements of W and Z bosons, and Drell-Yan
No full textMeasurements of Drell-Yan and W/Z-boson production in association with jets are an important test of electroweak and perturbative QCD predictions. Differential cross sections for Z-boson production, Z-boson production in association with jets and W-boson + a charm quark are presented from ATLAS and CMS. The data are compared to theoretical predictions provided by various Monte Carlo event generators
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