70,600 research outputs found
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
Measurement of the low-mass Drell-Yan differential cross section at √s = 7 TeV using the ATLAS detector
No full textThe differential cross section for the process Z/γ ∗ → ℓℓ (ℓ = e, μ) as a function of dilepton invariant mass is measured in pp collisions at s√ = 7 TeV at the LHC using the ATLAS detector. The measurement is performed in the e and μ channels for invariant masses between 26 GeV and 66 GeV using an integrated luminosity of 1.6 fb−1 collected in 2011 and these measurements are combined. The analysis is extended to invariant masses as low as 12 GeV in the muon channel using 35 pb−1 of data collected in 2010. The cross sections are determined within fiducial acceptance regions and corrections to extrapolate the measurements to the full kinematic range are provided. Next-to-next-to-leading-order QCD predictions provide a significantly better description of the results than next-to-leading-order QCD calculations, unless the latter are matched to a parton shower calculation
Dokuzuncu S n f Ö rencilerinin Devirli Ondal k Gösterimle lgili Kavram Yan lg lar
No full textBu çal man n amac , dokuzuncu s n f ö rencilerinin devirli ondal k gösterimle ilgili
kavram yan lg lar n belirlemektir. Çal man n amac do rultusunda kavram yan lg s
türleri göz önüne al narak devirli ondal k gösterim ilgili olas kavram yan lg lar na
yönelik aç k uçlu sorular içeren Devirli Ondal k Gösterim Tan Testi haz rlanm ve
dokuzuncu s n fta okuyan k rk ö renciye uygulanm t r. Ö rencilerden al nan yan tlar
detayl olarak incelenerek ö rencilerin kavram yan lg lar a r genelleme, a r
özelleme, yanl tercüme ve k s tl alg lama kategorilerine göre irdelenmi tir.
Ö renciler rasyonel say lar alt ö renme alan n n bir parças olan "devirli ondal k
gösterim" ile ilgili 6, 7, 8 ve 9. s n flarda deneyim ya amaktad rlar. Buna ra men, bu
çal man n bulgular ö rencilerin dokuzuncu s n fta bile bu konu hakk nda yayg n
kavram yan lg lar na sahip olduklar n göstermektedir. Sonuçlar, dokuzuncu s n f
ö rencilerinin devirli ondal k say larla ilgili a r genelleme, yanl tecrübe ve k s tl
alg lama türlerinde kavram yan lg lar na sahip olduklar n göstermektedir.The aim of this study is to identify misconceptions of nine grade students on the topic
of repeating decimal numbers. Data were obtained from forty students through
Diagnostic Test of Repeating Decimal Numbers including open-ended questions.
Questions were prepared according to the classification of misconceptions as
overgeneralization, overspecialization, mistranslation and limited conception. As a
part of rational numbers unit the topic of representation of repeating decimals is
introduced at 6, 7, 8 and 9 grades in our schools. In spite of this, findings of this study
illustrate that even nine grade students still have some common misconceptions about
this topic. Findings illustrated that most students misconceptions were based on
overgeneralization. In addition to this students also shared the other categories of
misconceptions as well
S n f ö retmeni adaylar n n sera etkisi hakk ndaki kavram yan lg lar
No full textAra t rma, s n f ö retmeni adaylar n n sera etkisi hakk ndaki kavram yan lg lar n tespit etmek amac yla gerçekle tirilmi tir. Karadeniz Teknik Üniversitesi Giresun E ilim Fakültesi S n f Ö retmenli i Program dördüncü s n fa devam eden 160 ö renci ara t rman n örneklemini olu turmu tur. 26 maddeden olu an likert tipi bir ölçek geli tirilmi ve ö rencilere uygulanm t r. Sonuçlar, ö rencilerin sera etkisi hakk nda 8 farkl yan lg ya sahip olduklar n göstermi tir. Ö rencilerin sahip olduklar yan lg lar düzeltmek için e itimcilere ve program geli tiricilere çe itli tavsiyelerde bulunulmu tur.The purpose of the research is to determine prospective classroom teachers' misconceptions of the greenhouse effect. 160 students from Karadeniz Technical University, Giresun Education Faculty, Classroom Teaching Programme were selected as a sample. A likert type scale which consists 26 items was developed and administered to determine the students' ideas. The results of the study showed that the students possess 8 different misconceptions of the greenhouse effect. Recommendations are made to educators and program developers for correcting the misconceptions students hold
FIGURE 3 in Sphaeropteris guangxiensis Y. F. Gu & Y. H. Yan (Cyatheaceae), a new species of tree fern from Southern China
No full textFIGURE 3. Fiddleheads and sori on pinnule segments.—A & D. Sphaeropteris brunoniana.—B & E. S. guangxiensis.—C & F. S. hainanensis.Published as part of Gu, Yu-Feng, Jiang, Ri-Hong, Liu, Bao-Dong & Yan, Yue-Hong, 2021, Sphaeropteris guangxiensis Y. F. Gu & Y. H. Yan (Cyatheaceae), a new species of tree fern from Southern China, pp. 69-74 in Phytotaxa 518 (1) on page 72, DOI: 10.11646/phytotaxa.518.1.8, http://zenodo.org/record/544801
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
The Genus Schizoprymnus Förster, 1863 (Hymenoptera, Braconidae, Brachistinae) from China, with Descriptions of Seven New Species
No full textThe species of the genus Schizoprymnus Förster, 1863 (Hymenoptera, Braconidae, Brachistinae) from China are revised. Seven new species, namely S. carinatus Yan and Chen, sp. nov., S. glabratus Yan and Chen, sp. nov., S. liui Yan and Chen, sp. nov., S. parvidentatus Yan and van Achterberg, sp. nov., S. punctiscutellaris Yan and Chen, sp. nov., S. septentrionalis Yan and Chen, sp. nov., and S. subspinosus Yan and Chen, sp. nov. are described and illustrated. In addition, S. telengai Tobias, 1976 is reported for the first time from China. An updated key to the Chinese species of the genus Schizoprymnus is included
Corrigendum to “Reliability assessment of generic geared wind turbines by GTST-MLD model and Monte Carlo simulation” (Renewable Energy (2015) 83 (222–233), (S0960148115003158), (10.1016/j.renene.2015.04.035))
No full textThe authors regret that the Order of Authors in this article published in November 2015 is incorrect. Thus, the objective of this Corrigendum is to re-establish the originally agreed Order of Authors, as described below. Order of Authors from published Article: Yan-Fu Li, PhD; Sebastien Valla; Enrico Zio, PhD. Corrected Order of Authors to implement with this Corrigendum: Sebastien Valla, Yan-Fu Li, PhD; Enrico Zio, PhD. The Corresponding author to contact for these changes are the Primary Author, Sebastien Valla (email below). The authors would like to apologise for any inconvenience caused
Evidence for the decay B0→J/ψω and measurement of the relative branching fractions of meson decays to J/ψη and J/ψη′
No full textFirst evidence of the B 0 → J / ψ ω decay is found and the B s 0 → J / ψ η and B s 0 → J / ψ η ′ decays are studied using a dataset corresponding to an integrated luminosity of 1.0 fb -1 collected by the LHCb experiment in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV. The branching fractions of these decays are measured relative to that of the B 0 → J / ψ ρ 0 decay:frac(B (B 0 → J / ψ ω), B (B 0 → J / ψ ρ 0)) = 0.89 ± 0.19 (stat) - 0.13 + 0.07 (syst),frac(B (B s 0 → J / ψ η), B (B 0 → J / ψ ρ 0)) = 14.0 ± 1.2 (stat) - 1.5 + 1.1 (syst) - 1.0 + 1.1 (frac(f d, f s)),frac(B (B s 0 → J / ψ η ′), B (B 0 → J / ψ ρ 0)) = 12.7 ± 1.1 (stat) - 1.3 + 0.5 (syst) - 0.9 + 1.0 (frac(f d, f s)), where the last uncertainty is due to the knowledge of f d / f s, the ratio of b-quark hadronization factors that accounts for the different production rate of B 0 and B s 0 mesons. The ratio of the branching fractions of B s 0 → J / ψ η ′ and B s 0 → J / ψ η decays is measured to befrac(B (B s 0 → J / ψ η ′), B (B s 0 → J / ψ η)) = 0.90 ± 0.09 (stat) - 0.02 + 0.06 (syst)
APC/C and SCFcyclin F Constitute a Reciprocal Feedback Circuit Controlling S-Phase Entry
No full textSummaryThe anaphase promoting complex/cyclosome (APC/C) is an ubiquitin ligase and core component of the cell-cycle oscillator. During G1 phase, APC/C binds to its substrate receptor Cdh1 and APC/CCdh1 plays an important role in restricting S-phase entry and maintaining genome integrity. We describe a reciprocal feedback circuit between APC/C and a second ubiquitin ligase, the SCF (Skp1-Cul1-F box). We show that cyclin F, a cell-cycle-regulated substrate receptor (F-box protein) for the SCF, is targeted for degradation by APC/C. Furthermore, we establish that Cdh1 is itself a substrate of SCFcyclin F. Cyclin F loss impairs Cdh1 degradation and delays S-phase entry, and this delay is reversed by simultaneous removal of Cdh1. These data indicate that the coordinated, temporal ordering of cyclin F and Cdh1 degradation, organized in a double-negative feedback loop, represents a fundamental aspect of cell-cycle control. This mutual antagonism could be a feature of other oscillating systems
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