Leaf water content (LWC) is very important in the growth of vegetation. LWC and leaf spectra change when leaves are under pest stress; exploring mechanism between LWC, spectra, stress can lay foundation for detection. In this study, we measured moso bamboo different damage levels, used Pearson–Lasso method to screen features, established a multiple linear regression (MLR) random forest (RFR) mo...

Electrical impedance spectra (100 Hz-800 kHz) were measured in leaves of Peperomia obtusifolia L. (a succulent) and Brassica oleracea L. (cabbage). By measuring impedances at three or more inter-electrode distances in a single leaf, electrode impedance and specific tissue impedance were separated. Analysis of impedance data from B. oleracea leaves in relation to an equivalent circuit model show...

The electronic spectra of carbon nanotubes and other nanoscale systems are quantized because of their small radii. Similar quantization in the phonon spectra has been difficult to observe because of the far smaller energy scale. We probed this regime by measuring the temperature-dependent specific heat of purified single-wall nanotubes. The data show direct evidence of one-dimensional quantized...

The exciton scattering (ES) approach attributes excited electronic states in quasi-1D branched polymer molecules to standing waves of quantum quasiparticles (excitons) scattered at the molecular vertices. We extract their dispersion and frequency-dependent scattering matrices at termini, ortho, and meta joints for pi-conjugated phenylacetylene-based molecules from atomistic time-dependent densi...

The calculation of the vibrational structure associated to electronic spectra in large molecules requires a Taylor expansion of the initial and final state potential energy surface (PES) around some reference nuclear structure. Vertical (V) and adiabatic (A) approaches expand the final state PES around the initial-state (V) or final-state (A) equilibrium structure. Simplest models only take int...

Excited-state geometries and electronic spectra of butadiene, acrolein, and glyoxal have been investigated by the symmetry adapted cluster configuration interaction (SAC-CI) method in their s-trans conformation. Valence and Rydberg states below the ionization threshold have been precisely calculated with sufficiently flexible basis sets. Vertical and adiabatic excitation energies were well repr...

Optical technologies can be developed as practical tools for monitoring plant health by providing unique spectral signatures that can be related to specific plant stresses. Signatures from thermal and fluorescence imaging have been used successfully to track pathogen invasion before visual symptoms are observed. Another approach for noninvasive plant health monitoring involves elucidating the m...

During greening of fat-storing cotyledons, the functional properties of the microbody population changes from that of glyoxysomes to that of leaf peroxisomes. The amount of microbody protein per cell is assumed to be substantially reduced [ 1,2,3] . Little is known about the mechansim of this change of microbody function. Recently, data obtained from labeling of microbody membranes with Cl4 and...

The spatial distribution of plant defenses within a leaf may be critical in explaining patterns of herbivory. The generalist lepidopteran larvae, Helicoverpa armigera (the cotton bollworm), avoided the midvein and periphery of Arabidopsis thaliana rosette leaves and fed almost exclusively on the inner lamina. This feeding pattern was attributed to glucosinolates because it was not evident in a ...