Now showing items 1-10 of 3771
Blueshift of the A-exciton peak in folded monolayer 1H-MoS2
(American Physical Society, 2013)
Second harmonic microscopy of monolayer MoS2
(American Physical Society, 2013)
We show that the lack of inversion symmetry in monolayer MoS2 allows strong optical second harmonic generation. The second harmonic of an 810-nm pulse is generated in a mechanically exfoliated monolayer, with a nonlinear susceptibility on the order of 10−7 m/V. The susceptibility reduces by a factor of seven in trilayers, and by about two orders ...
Strain rate dependent mechanical properties in single crystal nickel nanowires
(American Institute of Physics, 2013)
We measure the strain rate dependence of 0.2% offset yield stress in single-crystal nickel nanowires with diameters ranging from 80 to 300 nm. In situ tensile experiments with strain rates from 10 4 s 1 to 10 2 s 1 were conducted, and the small activation volume ( 10b3, where b is the Burgers vector length) and high strain-rate sensitivity ( 0.1) ...
Searches for supersymmetry using the M T2 variable in hadronic events produced in pp collisions at 8 TeV
Searches for supersymmetry (SUSY) are performed using a sample of hadronic events produced in 8 TeV pp collisions at the CERN LHC. The searches are based on the M T2 variable, which is a measure of the transverse momentum imbalance in an event. The data were collected with the CMS detector and correspond to an integrated luminosity of 19.5 fb−1. Two ...
Search for quark compositeness in dijet angular distributions from pp collisions at √s=7 TeV
A search for quark compositeness using dijet angular distributions from pp collisions at √s=7 TeV is presented. The search has been carried out using a data sample corresponding to an integrated luminosity of 2.2 fb−1, recorded by the CMS experiment at the LHC. Normalized dijet angular distributions have been measured for dijet invariant masses from ...
Airborne radar sounding evidence for deformable sediments and outcropping bedrock beneath Thwaites Glacier, West Antarctica
The geologic and morphologic records of prior ice sheet configurations show evidence of rapid, back-stepping, meltwater intensive retreats. However, the potential for such a retreat in a contemporary glacier depends on the lithology of the current ice sheet bed, which lies beneath kilometers of ice, making its physical properties difficult to constrain. ...
Search for heavy quarks decaying into a top quark and a W or Z boson using lepton + jets events in pp collisions at √s=7 TeV
Results are presented from a search for the pair-production of heavy quarks, QQ¯¯¯¯, that decay exclusively into a top quark and a W or Z boson. The search is performed using a sample of proton-proton collisions at √s=7 TeV corresponding to an integrated luminosity of 5.0 fb−1, collected by the Compact Muon Solenoid experiment. The signal region is ...
Observation and modeling of the evolution of Texas power plant plumes
(European Geosciences Union, 2012)
During the second Texas Air Quality Study 2006 (TexAQS II), a full range of pollutants was measured by aircraft in eastern Texas during successive transects of power plant plumes (PPPs). A regional photochemical model is applied to simulate the physical and chemical evolution of the plumes. The observations reveal that SO2 and NOy were rapidly removed ...
Transcriptional Delay Stabilizes Bistable Gene Networks
(American Physical Society, 2013-08)
Transcriptional delay can significantly impact the dynamics of gene networks. Here we examine how such delay affects bistable systems. We investigate several stochastic models of bistable gene networks and find that increasing delay dramatically increases the mean residence times near stable states. To explain this, we introduce a non-Markovian, ...