Although hyperspectral remotely sensed data are believed to be nonlinear, they are often modeled and processed by algorithms assuming that the data are realizations of some linear stochastic processes. This is likely due to the reason that either the nonlinearity of the data may not be strong enough, and the algorithms based on linear data assumption may still do the job, or the effective algorithms that are capable of dealing with nonlinear data are not widely available. The simplification on data characteristics, however, may compromise the effectiveness and accuracy of information extraction from hyperspectral imagery. In this paper, we are investigating the existence of non- linearity in hyperspectral data represented by a 4-m Airborne Visible/Infrared Imaging Spectrometer image acquired over an area of coastal forests on Vancouver Island. The method employed for the investigation is based on the statistical test using surrogate data, an approach often used in nonlinear time series analysis. In addition to the high-order autocorrelation, spectral angle is utilized as the discriminating statistic to evaluate the differences between the hyperspectral data and their surrogates. To facilitate the statistical test, simulated data sets are created under linear stochastic constraints. Both simulated and real hyperspectral data are rearranged into a set of spectral series where the spectral and spatial adjacency of the original data is maintained as much as possible. This paper reveals that the differences are statistically significant between the values of discriminating statistics derived from the hyperspectral data and their surrogates. This indicates that the selected hyperspectral data are nonlinear in the spectral domain. Algorithms that are capable of explicitly addressing the nonlinearity are needed for processing hyperspectral remotely sensed data.

In this paper, a kind of one-dimensional steady-state model is used to analyze and simulate the capillary motion of the working material in micro heat pipe. The character of this model is that it includes the influence of the interface friction, and the influence of the friction to the micro heat pipe’s performance is also simulated and analyzed. The maximum heat transport capacity and the optimizing size of the grooves are calculated by this model. Some experiments have been carried out to evaluate the simulation results.

Four binuclear dysprosium compounds incorporating the radical ligand 2-(4-oxidopyridyl)-4,4,5,5-tetramethylimidazolin-1-oxyl-3-oxide (PyNONIT) have been successfully synthesized under appropriate conditions. Centrosymmetric bimetallic Dy2O2 cores in all of the compounds through double-mu(2)-oxygen atoms of the N-oxide groups are realized in a metal-radical approach for the first time. Dimers 1 and 2, of the same formula {[Dy(hfac)(3)(PyNONIT)](2)}(2) (hfac = hexafluoroacetylacetonate) but obtained by different methods, which contain almost identical local symmetry of D-4d and Dy-(O)(2)-Dy bridging fashion, however, display no out-of-phase alternating-current (ac) signal for 1 and slow relaxation of the magnetization for 2 corresponding to the difference of the crystal packing mode. The adduct ([Dy(hfac)(3)(PyNONIT)](2)[Dy-0.5(hfac)(1.5)(H2O)](2)) (3) consists of two items, the dimer [Dy(hfac)(3)(PyNONIT)](2) and the monomer [Dy(hfac)(3)(H2O)(2)], where the symmetry of Dy-III ion in Dy2O2 decreases to D-2d, showing slow relaxation of the magnetization at lower temperature. Interestingly, a moisture-mediated reversible solid transformation between 1 and ([Dy(hfac)(3)(H2O)(PyNONIT)](2)) (4) has been investigated. Spongelike 1 can undergo a transition from eight to nine coordination at room temperature through hydration. A different coordination field is mostly responsible for no ac signal noticed for 4. The structural diversity of the Dy-2 family provides an opportunity to expand the investigation on 4f single molecule magnets. Approaches that the relaxation of the supramolecular dimer can be tuned to ON and OFF states modulated by the packing mode and ligand field are presented.

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The complex nonlinear dynamics of a rotor-rolling bearing system with crack is built by dynamic simulation software ADAMS. The transverse vibration response and swing response of rotor are studied on the basis of considering both the nonlinear contact force of rolling bearing and the impact of stiffness caused by crack. Furthermore, the influence factors of transverse vibration response are researched including speed, crack depth, crack angle and eccentricity. The simulation analysis demonstrated that it is an effective method to solve nonlinear dynamics of rotor-rolling bearing system with crack based on virtual prototyping technology. It provides a new method of feasibility study for fault diagnosis in the future.