A method for synthesizing of 2-nitrobenzaldehyde from 2-nitrobenzyl alcohol using ionic liquids (ILs) has been developed. The conversion of 2-nitrobenzyl alcohol and the selectivity of 2-nitrobenzaldehyde in the ionic...
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As a continuation of a recent linear analysis by Mao et al.(Acta Mech Sin,2010,26:355),in this paper we propose a general theoretical formulation for the compressing process in complex Newtonian fluid flows,which cove...
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As a continuation of a recent linear analysis by Mao et al.(Acta Mech Sin,2010,26:355),in this paper we propose a general theoretical formulation for the compressing process in complex Newtonian fluid flows,which covers gas dynamics,aeroacoustics,nonlinear thermoviscous acoustics,viscous shock layer,etc.,as its special *** principle on which our formulation is based is the maximally natural and dynamic Helmholtz decomposition of the Navier-Stokes equation,along with the kinematic Helmholtz decomposition of the velocity *** central results are the new dilatation equation and velocity-potential equation,which are the counterparts of vorticity transport equation and vector stream-function equation for the shearing process,*** couplings of the compressing process with shearing and thermal processes,including its physical sources,are carefully *** the possible applications and influences of the new formulation are yet to be explored,our preliminary discussion on the pros and cons of previous formulations pertain to acoustic analogy and that on the process splitting and coupling in highly compressible turbulence indicates that at least the formulation can serve as a new frame of reference by which one may gain some additional insight and thereby develop new approaches to the multi-processcomplex flow problems.
Cooperation and defection may be considered to be two extreme responses to a social dilemma. Yet the reality is much less clear-cut. Between the two extremes lies an interval of ambivalent choices, which may be captur...
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Cooperation and defection may be considered to be two extreme responses to a social dilemma. Yet the reality is much less clear-cut. Between the two extremes lies an interval of ambivalent choices, which may be captured theoretically by means of continuous strategies defining the extent of the contributions of each individual player to the common pool. If strategies are chosen from the unit interval, where 0 corresponds to pure defection and 1 corresponds to the maximal contribution, the question is what is the characteristic level of individual investments to the common pool that emerges if the evolution is guided by different benefit functions. Here we consider the steepness and the threshold as two parameters defining an array of generalized benefit functions, and we show that in a structured population there exist intermediate values of both at which the collective contributions are maximal. However, as the cost-to-benefit ratio of cooperation increases, the characteristic threshold decreases while the corresponding steepness increases. Our observations remain valid if more complex sigmoid functions are used, thus reenforcing the importance of carefully adjusted benefits for high levels of public cooperation.
The reduction of NOx emission via different coal combustion methods was studied in a two-stage reactor using 3 different coals. The NOx formation is effectively suppressed by reburning the gas from pyrolysis and parti...
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The reduction of NOx emission via different coal combustion methods was studied in a two-stage reactor using 3 different coals. The NOx formation is effectively suppressed by reburning the gas from pyrolysis and partial gasification of coal, making the NOx emission obviously lower than that of the air-staged combustion. It is found that the decoupling combustion leads to the higher NOx reduction rate, which is over 32% in comparison with the normal combustion. The NOx reduction rates vary with the coal properties. The smaller the fuel ratio (fixed carbon to volatile matter)at per nitrogen content in coal, the lower NOx emission is for reburning the combustible gas from pyrolysis and gasification and also for the decoupling combustion. The NOx emission due to reburning the partial gasification gas varies with the oxygen amount applied in the gasification, and the lowest NOx emission is realized in the oxygen concentration from 8% to 10%. A 1.4 MW industrial boiler was designed according to the principle of the decoupling combustion technology. The running data for the same coal show that the decoupling combustion reduces 32.9% NOx emission in comparison with the traditional combustion.
Calibration of a functional structural plant model is a challenging task because of the complexity of model structure. Parameter estimation through gradient-based optimization technique was highly dependent on initial...
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ISBN:
(纸本)9781467304290
Calibration of a functional structural plant model is a challenging task because of the complexity of model structure. Parameter estimation through gradient-based optimization technique was highly dependent on initial parameter values. This motivated the use of global sensitivity analysis technique to choose parameter subset in fitting the data sequence. Global sensitivity indices were computed using the source sink ratio as the output of interest, which regulates all organ growth. By fitting on chrysanthemum data from nine sampling dates, it is shown that sensitivity analysts method helps to identify the influential parameters for a given sampling date. As a result, fitting process is less dependent on the initial parameter values. Current work provides a new method of calibrating a plant growth model with multiple outputs.
Granular materials are ubiquitous in nature and engineering. They display both fluid- and solid-like behavior with fascinating complexity and remarkable uniqueness. Their behavior at different scales is strongly coupl...
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Granular materials are ubiquitous in nature and engineering. They display both fluid- and solid-like behavior with fascinating complexity and remarkable uniqueness. Their behavior at different scales is strongly coupled with each other because of high nonequilibrium constraints and finite size effects.
For a class of uncertain multi-input-multi-output (MIMO) discrete-time nonlinear systems with strong coupling and unstable zero-dynamics, an adaptive generalized predictive decoupling switching control method based on...
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For a class of uncertain multi-input-multi-output (MIMO) discrete-time nonlinear systems with strong coupling and unstable zero-dynamics, an adaptive generalized predictive decoupling switching control method based on unmodeled dynamic compensation is proposed. It is only required that the higher order nonlinear terms of the system to satisfy a linear growth condition, rather than the global boundedness condition widely used. The analysis of stability and convergence of the adaptive control method are performed. Moreover, in designing the nonlinear generalized predictive decoupling controller, we combine the adaptive-network-based fuzzy inference system (ANFIS) training with the "one-toone mapping" technique to adaptively estimate the unmodeled dynamics, so that the universal approximation property of ANFIS can be guaranteed. Finally, simulation results demonstrate the superiority of the proposed method and validate the theoretical analysis.
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