摘要 :
Contrarian behavior is a kind of self-organization in complex adaptive systems (CASs). Here we report the
existence of a transition point in a model resource-allocation CAS with contrarian behavior by using human
experiments, comp...
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Contrarian behavior is a kind of self-organization in complex adaptive systems (CASs). Here we report the
existence of a transition point in a model resource-allocation CAS with contrarian behavior by using human
experiments, computer simulations, and theoretical analysis. The resource ratio and system predictability serve
as the tuning parameter and order parameter, respectively. The transition point helps to reveal the positive or
negative role of contrarian behavior. This finding is in contrast to the common belief that contrarian behavior
always has a positive role in resource allocation, say, stabilizing resource allocation by shrinking the redundancy
or the lack of resources. It is further shown that resource allocation can be optimized at the transition point by
adding an appropriate size of contrarians. This work is also expected to be of value to some other fields ranging
from management and social science to ecology and evolution.
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摘要 :
We describe low energy electron microscopy (LEEM) studies of the behavior at high temperatures of step edges on the close-packed surfaces of refractory metal thin films grown by molecular beam epitaxy. The research includes bcc Mo...
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We describe low energy electron microscopy (LEEM) studies of the behavior at high temperatures of step edges on the close-packed surfaces of refractory metal thin films grown by molecular beam epitaxy. The research includes bcc Mo (011), V (011), Nb (011), and Ta (011), and comparison with bulk single crystals of Nb (011) and fcc Pt (111). Properties observed include faceting of individual steps, step-step interactions, and the interactions of steps with defects such as threading dislocations and with surface reconstructions. Step fluctuations on these surfaces are quantified. For Mo (011) observed by LEEM, the Fourier amplitudes are fit with an attachment model to obtain the step stiffness and its entropy, the step free energy, and its orientation dependence.
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摘要 :
Sinusoidally modulated ZnSeTe superlattices were fabricated by means of a novel MBE growth technique, in which the periodic modulation is achieved by substrate rotation in the presence of non-uniform flux distributions of Se and T...
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Sinusoidally modulated ZnSeTe superlattices were fabricated by means of a novel MBE growth technique, in which the periodic modulation is achieved by substrate rotation in the presence of non-uniform flux distributions of Se and Te, rather than by shutter openings and closings. The sinusoidal modulation of composition in the system naturally leads to a sinusoidal energy band profile, which in turn is expected to result in new and unique optical and electronic properties. We have performed extensive photoluminescence (PL) measurements on a series of sinusoidal ZnSeTe superlattices having various degrees of compositional modulation (i.e., various band offsets) and various periods. The observed transition energies in these superlattices can be successfully analyzed in terms of an adaptation of the nearly free electron model.
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摘要 :
Air-impact molding is one of the modern clay-bonded sand compaction methods. To study the air-impact compaction pro- cess, by experiment only, is expensive and time-consuming. Numerical simulation of air-impact molding can provide...
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Air-impact molding is one of the modern clay-bonded sand compaction methods. To study the air-impact compaction pro- cess, by experiment only, is expensive and time-consuming. Numerical simulation of air-impact molding can provide a useful tool for optimizing pattern plate utilization, improving mold quality and modifying molding machine design. The research presented in this paper is the application of dynamic Finite Element Method (FEM) to simulate the compac- tion process of molding sand with air-impact molding technol- ogy.
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摘要 :
Lack of plasticity is the main drawback for nearly all ultrafine-grained (UFG) materials, which restricts their practical applications. Bulk UFG Cu-Al alloys have been fabricated by using equal channel angular pressing technique. ...
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Lack of plasticity is the main drawback for nearly all ultrafine-grained (UFG) materials, which restricts their practical applications. Bulk UFG Cu-Al alloys have been fabricated by using equal channel angular pressing technique. Its ductility was improve
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