4,617 research outputs found
Study the Heavy Molecular States in Quark Model with Meson Exchange Interaction
Some charmonium-like resonances such as X(3872) can be interpreted as
possible molecular states. Within the quark model, we study
the structure of such molecular states and the similar
molecular states by taking into account of the light meson exchange (,
, , and ) between two light quarks from different
mesons
Dynamical study of the possible molecular state X(3872) with the s-channel one gluon exchange interaction
The recently observed X(3872) resonance, which is difficult to be assigned a
conventional charmonium state in the quark model, may be interpreted
as a molecular state. Such a molecular state is a hidden flavor four quark
state because of its charmonium-like quantum numbers. The s-channel one gluon
exchange is an interaction which only acts in the hidden flavor multi-quark
system. In this paper, we will study the X(3872) and other similiar hidden
flavor molecular states in a quark model by taking into account of the
s-channel one gluon exchange interaction
Disturbance observer-based adaptive sliding mode synchronization control for uncertain chaotic systems
The synchronization control problem of a class of chaotic systems with unknown uncertainties and outside perturbation is addressed in this article by employing an innovative adaptive sliding mode controller (SM, SMC) constructed using a disturbance observer (DO). For the synchronous error system, the external disturbances estimated by the disturbance observer cannot be measured directly. If the appropriate gain matrix is chosen, the DO can approximate the unknown external disturbances well. Then a continuous adaptive SM controller based on the DO's output is designed by using adaptive techniques and the system dimensional expansion method. The Duffing-Holmes chaotic system is finally selected to numerically test the efficiency of the suggested strategy
Comparison between empirical or functional sinks of organs - Application on Tomato plant
International audienceBiomass partitioning among organs depends on their sink strengths, i.e. their capacity to attract assimilates. Using a descriptive approach, where plant development is driven by thermal time, and empirical laws fitted from experimental data, it is possible to trace back by inverse method the dynamics of biomass partitioning among organs. However, the descriptive sink function suffers from the drawbacks that organ development and biomass accumulation are not interactively related. Moreover, many parameters are required and are difficult to be measured accurately. In this paper an alternative organ sink strength definition is proposed, in which the organ sink size is related to the maximum organ biomass, which in turn depends on its primordium size. The sink strength increases proportionally to its size at the early growth stage and decreases by dampening when its mass approaches the final mass. Comparisons to the standard empirical sink function used in the GreenLab model were conducted on tomato plants. The new functional sinks are more biologically relevant and simulated rather adequately the organ biomass evolution. Further improvement is ongoing to increase simulation accuracy
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