923 research outputs found
Centralizers of derived-from-Anosov systems on : rigidity versus triviality
In this paper, we study the centralizer of a partially hyperbolic
diffeomorphism on which is homotopic to an Anosov automorphism,
and we show that either its centralizer is virtually trivial or such
diffeomorphism is smoothly conjugate to its linear part.Comment: 24 page
A Multilayer Feed Forward Small-World Neural Network Controller and Its Application on Electrohydraulic Actuation System
Being difficult to attain the precise mathematical models, traditional control methods such as proportional integral (PI) and proportional integral differentiation (PID) cannot meet the demands for real time and robustness when applied in some nonlinear systems. The neural network controller is a good replacement to overcome these shortcomings. However, the performance of neural network controller is directly determined by neural network model. In this paper, a new neural network model is constructed with a structure topology between the regular and random connection modes based on complex network, which simulates the brain neural network as far as possible, to design a better neural network controller. Then, a new controller is designed under small-world neural network model and is investigated in both linear and nonlinear systems control. The simulation results show that the new controller basing on small-world network model can improve the control precision by 30% in the case of system with random disturbance. Besides the good performance of the new controller in tracking square wave signals, which is demonstrated by the experiment results of direct drive electro-hydraulic actuation position control system, it works well on anti-interference performance
Combustion Behaviour of Fe2O3-coated Zirconium Particles in Air
AbstractZirconium metal powder is widely used in aerospace and military as a metal fuel because of its high combustion rate and heat. This powder is used to produce flash powder, fireworks, artillery shells, timing bomb fuses and solid propellant rocket fuel. To comply with the special requirements for aerospace and military applications, zirconium particles are coated with Fe2O3 ferrite magnetite nanoparticles to form a core-shell structure. This process alters the combustion performance of the coated zirconium dust. In this study, the combustion behaviour of Fe2O3-coated zirconium particles in the air is explored. Scanning electron microscopy, X-ray diffraction, thermogravimetry and differential scanning calorimetry are used to examine the micromorphology, phase composition, crystal structure, thermal stability and reactivity of Fe2O3-coated zirconium particles. The combustion behaviour is presented, with the coating layer of Fe2O3-coated zirconium particles generating a replacement reaction with the inner core zirconium. The inner zirconium induced an oxidation-reduction reaction with oxygen and pure Fe was oxidised at high temperatures. The decomposition reaction was due to the residue of Fe2O3 that did not react with zirconium
A multi-channel photometric detector for multi-component analysis in flow injection analysis
The detector, a multi-channel photometric detector, described in this
paper was developed using multi-wavelength LEDs (light emitting
diode) and phototransistors for absorbance measurement controlled
by an Intel 8031 8-bit single chip microcomputer. Up to four flow
cells can be attached to the detector. The LEDs and phototransistors
are both inexpensive, and reliable. The results given by the detector
for simultaneous determination of trace amounts of cobalt and
cadmium in zinc sulphate electrolyte are reported. Because of the
newly developed detector, this approach employs much less hardware
apparatus than by employing conventional photometric detectors
Recommended from our members
Extracellular signal-regulated kinase 5 promotes acute cellular and systemic inflammation.
Inflammatory critical illness is a syndrome that is characterized by acute inflammation and organ injury, and it is triggered by infections and noninfectious tissue injury, both of which activate innate immune receptors and pathways. Although reports suggest an anti-inflammatory role for the mitogen-activated protein kinase (MAPK) extracellular signal-regulated kinase 5 (ERK5), we previously found that ERK5 mediates proinflammatory responses in primary human cells in response to stimulation of Toll-like receptor 2 (TLR2). We inhibited the kinase activities and reduced the abundances of ERK5 and MEK5, a MAPK kinase directly upstream of ERK5, in primary human vascular endothelial cells and monocytes, and found that ERK5 promoted inflammation induced by a broad range of microbial TLR agonists and by the proinflammatory cytokines interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α). Furthermore, we found that inhibitors of MEK5 or ERK5 reduced the plasma concentrations of proinflammatory cytokines in mice challenged with TLR ligands or heat-killed Staphylococcus aureus, as well as in mice that underwent sterile lung ischemia-reperfusion injury. Finally, we found that inhibition of ERK5 protected endotoxemic mice from death. Together, our studies support a proinflammatory role for ERK5 in primary human endothelial cells and monocytes, and suggest that ERK5 is a potential therapeutic target in diverse disorders that cause inflammatory critical illness
- …