23,544 research outputs found
Monotonicity results and bounds for the inverse hyperbolic sine
In this note, we present monotonicity results of a function involving to the
inverse hyperbolic sine. From these, we derive some inequalities for bounding
the inverse hyperbolic sine.Comment: 3 page
Fluctuations in Number of Cercospora beticola Conidia in Relationship to Environment and Disease Severity in Sugar Beet
All content of Phytopathology is open access without restriction 12 months after publicationCercospora leaf spot, caused by Cercospora beticola, is the most damaging foliar disease of sugar beet in Minnesota (MN) and North Dakota (ND). Research was conducted to characterize the temporal progression of aerial concentration of C. beticola conidia in association with the environment and disease severity in sugar beet. In 2003 and 2004, volumetric spore traps were placed within inoculated sugar beet plots to determine daily dispersal of conidia at Breckenridge, MN, and St. Thomas, ND. Plots were rated weekly for disease severity. At both locations, conidia were first collected in early July 2003 and late June in 2004. Peaks of conidia per cubic meter of air were observed with maxima in late August 2003 and in early September 2004 at both locations. Peaks of airborne conidium concentration were significantly correlated with the average temperature of daily hours when relative humidity was greater than 87%. Weekly mean hourly conidia per cubic meter of air was significantly (P <0.01) associated with disease severity during both years and across locations. This study showed that C. beticola conidial numbers may be used to estimate potential disease severity that, with further research, could be incorporated in a disease forecasting model to rationalize Cercospora leaf spot management.Peer reviewe
Generating EPR beams in a cavity optomechanical system
We propose a scheme to produce continuous variable entanglement between
phase-quadrature amplitudes of two light modes in an optomechanical system. For
proper driving power and detuning, the entanglement is insensitive with bath
temperature and of mechanical oscillator. Under realistic experimental
conditions, we find that the entanglement could be very large even at room
temperature.Comment: 4.1 pages, 4 figures, comments are welcome; to appear in PRA,
published version with corrections of typo
On the Application of Gluon to Heavy Quarkonium Fragmentation Functions
We analyze the uncertainties induced by different definitions of the momentum
fraction in the application of gluon to heavy quarkonium fragmentation
function. We numerically calculate the initial fragmentation
functions by using the non-covariant definitions of with finite gluon
momentum and find that these fragmentation functions have strong dependence on
the gluon momentum . As , these fragmentation
functions approach to the fragmentation function in the light-cone definition.
Our numerical results show that large uncertainties remains while the
non-covariant definitions of are employed in the application of the
fragmentation functions. We present for the first time the polarized gluon to
fragmentation functions, which are fitted by the scheme exploited in
this work.Comment: 11 pages, 7 figures;added reference for sec.
C-Cl Bond Fission, Hcl Elimination, And Secondary Radical Decomposition In The 193 Nm Photodissociation Of Allyl Chloride
The primary photodissociation dynamics of allyl chloride upon excitation at 193 nm is investigated in a crossed laser-molecular beam scattering apparatus. Tunable vacuum ultraviolet (VUV) photoionization of the products provides a unique ability to learn about the secondary reaction products of the nascent photoproducts formed. The data show evidence for four significant primary reaction channels: a previously unidentified low kinetic energy C-Cl bond fission channel producing unstable allyl radicals, an excited state C-Cl bond fission channel producing Cl atoms with high translational energy, an HCl elimination pathway releasing significant energy to product translation to HCl and its momentum-matched mass 40 partner, and an HCl elimination channel producing low kinetic energy HCl products and predominantly unstable mass 40 products. The measured branching of these primary reaction channels of [all C-Cl] : [fast C-Cl] : [slow C-Cl] : [fast HCl] : [slow HCl] : [all HCl] is 1.00: 0.971: 0.029: 0.291: 0.167: 0.458 (where fast refers to the high recoil kinetic energy channels). The high internal energy allyl radicals formed in the slow C-Cl fission pathway of allyl chloride further dissociate/isomerize, as do the unstable mass 40 products formed in the HCl elimination pathways, and these products are investigated. Photoionization efficiency (PIE) curves of the HCl product suggest that a three-centered elimination mechanism contributes significantly to an observed HCl elimination reaction. (C) 2002 American Institute of Physics
A semismooth newton method for the nearest Euclidean distance matrix problem
The Nearest Euclidean distance matrix problem (NEDM) is a fundamentalcomputational problem in applications such asmultidimensional scaling and molecularconformation from nuclear magnetic resonance data in computational chemistry.Especially in the latter application, the problem is often large scale with the number ofatoms ranging from a few hundreds to a few thousands.In this paper, we introduce asemismooth Newton method that solves the dual problem of (NEDM). We prove that themethod is quadratically convergent.We then present an application of the Newton method to NEDM with -weights.We demonstrate the superior performance of the Newton method over existing methodsincluding the latest quadratic semi-definite programming solver.This research also opens a new avenue towards efficient solution methods for the molecularembedding problem
Universal scattering behavior of co-assembled nanoparticle-polymer clusters
Water-soluble clusters made from 7 nm inorganic nanoparticles have been
investigated by small-angle neutron scattering. The internal structure factor
of the clusters was derived and exhibited a universal behavior as evidenced by
a correlation hole at intermediate wave-vectors. Reverse Monte-Carlo
calculations were performed to adjust the data and provided an accurate
description of the clusters in terms of interparticle distance and volume
fraction. Additional parameters influencing the microstructure were also
investigated, including the nature and thickness of the nanoparticle adlayer.Comment: 5 pages, 4 figures, paper published in Physical Review
Concise sharpening and generalizations of Shafer's inequality for the arc sine function
In this paper, by a concise and elementary approach, we sharpen and
generalize Shafer's inequality for the arc sine function, and some known
results are extended and generalized.Comment: 5 page
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