7,409 research outputs found
Beads-on-String Model for Virtual Rectum Surgery Simulation
A beads-on-string model is proposed to handle the deformation and collision of the rectum in virtual surgery simulation. The idea is firstly inspired by the observation of the similarity in shape shared by a rectum with regular bulges and a string of beads. It is beneficial to introduce an additional layer of beads, which provides an interface to map the deformation of centreline to the associated mesh in an elegant manner and a bounding volume approximation in collision handling. Our approach is carefully crafted to achieve high computational efficiency and retain its physical basis. It can be implemented for real time surgery simulation application
Mid-IR Multiwavelength Difference Frequency Generation Based on Fiber Lasers
A mid-IR multiwavelength difference frequency generation (DFG) laser source with fiber laser fundamental lights is demonstrated by using the dispersion property of PPLN to broaden the quasi-phase-matching (QPM) acceptance bandwidth (BW). Our results show that the QPM BW for the pump YDFL is much larger than that for the signal EDFL. Using a multiwavelength YDFL and a single-wavelength EDFL as the pump and the signal lights, the DFG laser source can simultaneously emit 14 mid-IR wavelengths with the spacing of 14nm at a fixed PPLN temperature. Moreover, mid-IR multiwavelength lasing lines can be synchronously tuned between 3.28 and 3.47μm
J/\psi polarization in photo-production up-to the next-to-leading order of QCD
We investigate the J/psi polarization in photoproduction at the Hadron
Electron Ring Accelerator(HERA) up to the next-to-leading order of QCD. The
results show that the transverse momentum p_t and energy fraction z
distributions of J/psi production do not agree with the observed ones very
well. The theoretical uncertainties for the z distributions of the J/psi
polarization parameters with respect to various choices of the renormalization
and factorization scales are too large to give an accurate prediction. The
uncertainties for the p_t distributions of these parameters are small when
p_t>3GeV and the obtained p_t distributions can not describe the experimental
data even in this region.Comment: 5 pages, 3 figures. Discussion on the theoretical uncertainties from
the choice of renormalization scale was adde
2-(2-ChloroÂphenÂyl)-2,3-dihydroÂquinazolin-4(1H)-one
The title compound, C14H11ClN2O, was synthesized by the reaction of 2-chloroÂbenzaldehyde and 2-aminoÂbenzamide in an ionic liquid. The pyrimidine ring adopts a skew-boat conformation and the two benzene rings make a dihedral angle of 87.1 (1)°. In the crystal, N—H⋯O and C—H⋯N hydrogen bonding links the molÂecules along b
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