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11.
α-Trinitrotoluene can coexist at ambient temperatures in either a monoclinic or an orthorhombic phase. Nitrogen-14 NQR spectra were obtained for each phase at 77 K using Fourier transform multiple-pulse NQR methods. For each spectrum twelve resonance lines were detected. These were further paired up as six corresponding ν? and ν+ sets by a simple level crossing method. The six NQR inequivalent sites were further uniquely matched to the six crystallographic sites described by J.R.C. Duke, by considering the effect of the large twist angles of the C-nitro groups about the CN bond axis on the nitrogen p- π orbital occupation. Results are also presented in the two similar compounds, s-Trinitrobenzene and Trinitro-m-Xylene. 相似文献
12.
Junker BH Hesse M Burgess B Masurekar P Connors N Seeley A 《Applied biochemistry and biotechnology》2004,119(3):241-277
Culture pelleting and morphology has a strong influence on process productivity and success for fungal and filamentous bacterial
cultures. This impact is particularly evident with early phase secondary metabolite processes with limited process definition.
A compilation of factors affecting filamentous or pelleting morphology described in the literature indicates potential leads
for developing process-specific control methodologies. An evaluation of the factors mediating citric acid production is one
example of an industrially important application of these techniques. For five model fungal and filamentous bacterial processes
in an industrial fermentation pilot plant, process development strategies were developed and effectively implemented with
the goal of achieving reasonable fermentation titers early in the process development cycle. Examples of approaches included
the use of additives to minimize pelleting in inoculum shake flasks, the use of large-volume frozen bagged inoculum obtained
from agitated seed fermentors, and variations in production medium composition and fermentor operating conditions. Results
were evaluated with respect to productivity of desired secondary metabolites as well as process scalability. On-line measurements
were utilized to indirectly evaluate the cultivation impact of changes in medium and process development. Key laboratory to
pilot plant scale-up issues also were identified and often addressed in subsequent cultivations. 相似文献
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14.
The symmetric sinc-Galerkin method developed by Lund, when appliedto the second-order self-adjoint boundary value problem, givesrise to a symmetric coefficient matrix has a special structureso that it can be advantageously used in solving the discretesystem. In this paper, we employ the preconditioned conjugategradient method with banded matrices as preconditioners. Weprove that the condition number of the preconditioned matrixis uniformly bounded by a constant independent of the size ofthe matrix. In particular, we show that the solution of an n-by-ndiscrete symmetric sinc-Galerkin system can be obtained in O(nlog n) operations. We also extend our method to the self-adjointelliptic partial differential equation. Numerical results aregiven to illustrate the effectiveness of our fast iterativesolvers. 相似文献
15.
The angular distribution of the five-fold differential cross section for the electron impact double ionization of He (21
S) and He (23
S) has been studied. The kinematical conditions for maxima/minima in the angular distribution for the two cases have been compared.
The two-step process for the double ionization is found to contribute very little in the triplet case. 相似文献
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18.
Interaction between an electronic and a biological circuit has been investigated for a pair of electrically connected nonlinear oscillators, with a spontaneously oscillating olivary neuron as the single-cell biological element. By varying the coupling strength between the oscillators, we observe a range of behaviors predicted by model calculations, including a reversible low-energy dissipation "amplitude death" where the oscillations in the coupled system cease entirely. 相似文献
19.
Rashaad E. T. Jones Erik S. Connors Mary E. Mossey John R. Hyatt Neil J. Hansen Mica R. Endsley 《Computational & Mathematical Organization Theory》2011,17(3):272-295
This paper describes work on the development of an actionable model of situation awareness for Army infantry platoon leaders
using fuzzy cognitive mapping techniques. Developing this model based on the formal representation of the platoon leader provided
by the Goal-Directed Task Analysis (GDTA) methodology advances current cognitive models because it provides valuable insight
on how to effectively support human cognition within the decision-making process. We describe the modeling design approach
and discuss validating the model using the VBS2 simulation environment. 相似文献
20.
Adare A Afanasiev S Aidala C Ajitanand NN Akiba Y Al-Bataineh H Alexander J Aoki K Aramaki Y Atomssa ET Averbeck R Awes TC Azmoun B Babintsev V Bai M Baksay G Baksay L Barish KN Bassalleck B Basye AT Bathe S Baublis V Baumann C Bazilevsky A Belikov S Belmont R Bennett R Berdnikov A Berdnikov Y Bickley AA Bok JS Boyle K Brooks ML Buesching H Bumazhnov V Bunce G Butsyk S Camacho CM Campbell S Chen CH Chi CY Chiu M Choi IJ Choudhury RK Christiansen P Chujo T Chung P Chvala O Cianciolo V Citron Z 《Physical review letters》2011,107(25):252301
Flow coefficients ν(n) for n=2, 3, 4, characterizing the anisotropic collective flow in Au+Au collisions at √s(NN)=200 GeV, are measured relative to event planes Ψ(n), determined at large rapidity. We report ν(n) as a function of transverse momentum and collision centrality, and study the correlations among the event planes of different order n. The ν(n) are well described by hydrodynamic models which employ a Glauber Monte Carlo initial state geometry with fluctuations, providing additional constraining power on the interplay between initial conditions and the effects of viscosity as the system evolves. This new constraint can serve to improve the precision of the extracted shear viscosity to entropy density ratio η/s. 相似文献