Despite the biological and societal importance of cellulose, the molecular mechanism by which it is synthesized is now only beginning to emerge. Humans have used cellulose for millennia as a material and an energy source, and the advent of a lignocellulosic fuel industry will elevate it to the primary carbon source for the burgeoning renewable energy sector. Zimmer, JochenĬellulose is the most abundant biopolymer on Earth, and certain organisms from bacteria to plants and animals synthesize cellulose as an extracellular polymer for various biological functions.
Ī Molecular Description of Cellulose Biosynthesis The assay differs from the plaque assay described in Chapter 10 (December 1987 Revision) in that it is based upon the direct microscopic viewing of cells for virus-induced. This chapter describes a quantal method for assaying culturable human enteric viruses from water matrices. On the other hand, the SC method can be much faster than the quantal method in exploratory work with different potential functions, where it is convenient to use finite-difference methods to evaluate the partial derivatives required in nonlinear fitting. Application of this method to the analysis of 9500 assigned lines in the I2A ↠X spectrum fails to alter the quantal-SC disparities found for the A-state RKR curve from a previous analysis. In contrast, the DPF RKR method resembles the quantal DPF methods now increasingly used to analyze diatomic spectral data, but with the eigenvalues obtained from SC phase integrals.
The pursuit of a direct-potential-fitting (DPF) RKR method is motivated by the notion that some of the limitations of RKR potentials may be innate, from their generation by an exact inversion of approximate quantities: the vibrational energy GÏ… and rotational constant BÏ… from least-squares analysis of spectroscopic data. One particular aspect of this is better agreement between quantal and SC estimates of the zero-point vibrational energy, supporting the need for the Y00 correction in this context. The comparisons show higher levels of agreement than generally recognized, when the SC calculations incorporate a quantum defect correction to the vibrational quantum number, in keeping with the Kaiser modification. Quantal and semiclassical (SC) eigenvalues are compared for three diatomic molecular potential curves: the X state of CO, the X state of Rb2, and the A state of I2. As a first application of the approach, we analyze the fragment mass distribution in 48Ca+ 238U collisions at the center-of-mass energy Ec.m.=193 MeV and compare the calculations with the experimental data.Ī direct potential fitting RKR method: Semiclassical vs. This powerful description does not involve any adjustable parameter, includes the effects of shell structure, and is consistent with the fluctuation-dissipation theorem of the nonequilibrium statistical mechanics. As a result, the primary fragment mass and charge distribution functions are determined entirely in terms of the mean-field properties.
The quantal transport coefficients are determined by the occupied single-particle wave functions of the time-dependent Hartree-Fock equations. S.Įmploying the stochastic mean-field (SMF) approach, we develop a quantal diffusion description of the multi-nucleon transfer in heavy-ion collisions at finite impact parameters. Quantal diffusion description of multinucleon transfers in heavy-ion collisionsĪyik, S.
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