Antarctic snowmelt detection for QuikSCAT scatterometer data based on mathematical morphology combined with wavelet transform

225-232Microwave scatterometer is sensitive to the melting snow. When the freeze-thaw phenomenon occurs, the backscatter coefficients will have a sharp rising and falling mutation. Mathematical morphology has the characteristics with edge-preserving filter and wavelet transform has the characteristics with the automatic edge extraction, which does not depend on the priori snowmelt information. A new automatic Antarctic snowmelt detection method was proposed based on mathematical morphology combined with wavelet transform. This method improves the snowmelt detection accuracy, because this method can remove the interference of the edge extraction. Melt onset date, end date and duration can be obtained with high accuracy by identifying and tracking the sharp rising and falling edge. Compare the snowmelt results in this work with the temperature of ten automatic weather stations (AWS), which shows that the snowmelt detection method proposed in the paper improves the detection accuracy from about 50 % to 62.5 % in AWS Cape Denison

Nondegeneracy of positive bubble solutions for generalized energy-critical Hartree equations

We show the nondegeneracy of positive bubble solutions for generalized energy-critical Hartree equations (NLH) \begin{equation*} -{\Delta u}\sts{x} -{\bm\alpha}\sts{N,\lambda} \int_{\R^N} { \frac{ u^{p}\sts{y}}{\pabs{\,x-y\,}{\lambda}} }\diff{y}\, u^{p-1}\sts{x} =0,\quad x\in \R^N \end{equation*} where $u(x)$ is a real-valued function, $N\geq 3$, $0<\lambda<N$, $p=\frac{2N-\lambda}{N-2}$ and {\bm\alpha}\sts{N,\lambda} is a constant. It generalizes the results for the whole range $0<\lambda<N$ in \cite{DY2019dcds, GWY2020na, LTX2021, MWX:Hartree} and confirms an open nondegeneracy problem in \cite{GMYZ2022cvpde}. Firstly, by the stereographic projection and sharp Hardy-Littlewood-Sobolev inequality on the sphere $\S^N$ in \cite{FL2012}, we give an alternative proof of the existence of the extremizer of sharp Hardy-Littlewood-Sobolev inequality in $\R^N$ without use of the rearrangement inequalities in \cite{lieb2001analysis}, which is related to the existence of positive bubble solutions of (NLH). Secondly, by making use of the Green function, we obtain an integral form in $\R^N$ of the corresponding linearized equation around positive bubble solutions under suitable decay condition, and its equivalent integral form on the sphere $\S^N$ via the stereographic projection. Lastly, together with the key spherical harmonic decomposition and the Funk-Hecke formula of the spherical harmonic functions in \cite{AH2012, DX2013book, SteinW:Fourier anal}, we can obtain the nondegeneracy of positive bubble solutions for generalized energy-critical Hartree equation (NLH), which is inspired by Frank and Lieb in \cite{FL2012am,FL2012}.Comment: 26 pages. Any comment is welcom

Dynamics of radial threshold solutions for generalized energy-critical Hartree equation

In this paper, we study long time dynamics of radial threshold solutions for the focusing, generalized energy-critical Hartree equation and classify all radial threshold solutions. The main arguments are the spectral theory of the linearized operator, the modulational analysis and the concentration compactness rigidity argument developed by T. Duyckaerts and F. Merle to classify all threshold solutions for the energy critical NLS and NLW in \cite{DuyMerle:NLS:ThresholdSolution, DuyMerle:NLW:ThresholdSolution}, later by D. Li and X. Zhang in \cite{LiZh:NLS, LiZh:NLW} in higher dimensions. The new ingredient here is to solve the nondegeneracy of positive bubble solutions with nonlocal structure in $\dot H^1(\R^N)$ (i.e. the spectral assumption in \cite{MiaoWX:dynamic gHartree}) by the nondegeneracy result of positive bubble solution in $L^{\infty}(\R^N)$ in \cite{LLTX:Nondegeneracy} and the Moser iteration method in \cite{DiMeVald:book}, which is related to the spectral analysis of the linearized operator with nonlocal structure, and plays a key role in the construction of the special threshold solutions, and the classification of all threshold solutions.Comment: 41 pages. All comments are welcom

Value Congruence: A Study of Green Transformational Leadership and Employee Green Behavior

This study examined the extent to which the impact of green transformational leadership on employee green behavior through follower perceptions of value congruence. Path analyzing on data from 193 subordinate-leader dyads showed that followers’ value congruence with their leader mediated the effects of green transformational leadership on employee green behavior. Results also supported that green identity moderated the indirect effect of green transformational leadership on employee green behavior through value congruence, such that the indirect effect was more positive when green identity was high than when it was low. These findings provided valuable contribution to green transformational leadership, value congruence, and employee green behavior by exploring the relationship between them. Practical implications and directions for future research are also discussed

Bright solitons in a spin-orbit-coupled dipolar Bose-Einstein condensate trapped within a double-lattice

By effectively controlling the dipole-dipole interaction, we investigate the characteristics of the ground state of bright solitons in a spin-orbit coupled dipolar Bose-Einstein condensate. The dipolar atoms are trapped within a double-lattice which consists of a linear and a nonlinear lattice. We derive the motion equations of the different spin components, taking the controlling mechanisms of the diolpe-dipole interaction into account. An analytical expression of dipole-dipole interaction is derived. By adjusting the dipole polarization angle, the dipole interaction can be adjusted from attraction to repulsion. On this basis, we study the generation and manipulation of the bright solitons using both the analytical variational method and numerical imaginary time evolution. The stability of the bright solitons is also analyzed and we map out the stability phase diagram. By adjusting the long-range dipole-dipole interaction, one can achieve manipulation of bright solitons in all aspects, including the existence, width, nodes, and stability. Considering the complexity of our system, our results will have enormous potential applications in quantum simulation of complex systems

Symmetry-protected higher-order exceptional points in staggered flatband rhombic lattices

Higher-order exceptional points (EPs), which appear as multifold degeneracies in the spectra of non-Hermitian systems, are garnering extensive attention in various multidisciplinary fields. However, constructing higher-order EPs still remains as a challenge due to the strict requirement of the system symmetries. Here we demonstrate that higher-order EPs can be judiciously fabricated in PT -symmetric staggered rhombic lattices by introducing not only on-site gain/loss but also nonHermitian couplings. Zero-energy flatbands persist and symmetry-protected third-order EPs (EP3) arise in these systems owing to the non-Hermitian chiral/sublattice symmetry, but distinct phase transitions and propagation dynamics occur. Specifically, the EP3 arises at the Brillouin zone (BZ) boundary in the presence of on-site gain/loss. The single-site excitations display an exponential power increase in the PT -broken phase. Meanwhile, a nearly flatband sustains when a small lattice perturbation is applied. For the lattices with non-Hermitian couplings, however, the EP3 appears at the BZ center. Quite remarkably, our analysis unveils a dynamical delocalization-localization transition for the excitation of the dispersive bands and a quartic power increase beyond the EP3. Our scheme provides a new platform towards the investigation of the higher-order EPs, and can be further extended to the study of topological phase transitions or nonlinear processes associated with higher-order EPs.Comment: 10 pages, 10 figure

Synthesis of polyacrylamide-based aerosol fixative and its fixation effect on tellurium aerosol

The removal control of radioactive aerosols in a nuclear emergency is an important issue, and capture fixation is a parameter for studying the purification effect of aerosol fixatives on aerosols. Herein, PAM-g-PAA, PAM-g-PHEA, and PAM-g-PAA/PHEA were obtained by chemical grafting with polyacrylamide as the substrate, acrylic acid and 2-hydroxyethyl acrylate as grafting monomers. The grafting product was confirmed by infrared spectroscopy and the grafting rate was calculated. The microstructure of different products were compared and discussed by scanning electron microscope images of freeze-drying and film formation. The capture and sedimentation effects of tellurium (simulated polonium) aerosol were studied by surface tension and fixed sedimentation experiments (PAM, PAM-g-PAA, PAM-g-PHEA, PAM-g-PAA/PHEA aqueous solution), and the mechanism of aerosol fixation was discussed. The results showed that the surface tension of the grafted product was significantly lower than that of the substrate PAM. Among them, the aerosol fixing agent PAM-g-PHEA grafted with HEA modified polyacrylamide can more effectively capture and fix tellurium aerosol particles, and its fixed sedimentation efficiency is 94.34%, which provides a research idea for the purification of polonium radioactive aerosol by atomization fixation method

MSH2 and MSH6 in mismatch repair system account for soybean (Glycine max (L.) Merr.) tolerance to cadmium Toxicity by determining DNA damage response

Our aim was to investigate DNA mismatch repair (MMR) genes regulating cadmium tolerance in two soybean cultivars. Cultivars Liaodou 10 (LD10, Cd-sensitive) and Shennong 20 (SN20, Cd-tolerant) seedlings were grown hydroponically on Murashige and Skoog (MS) media containing 0–2.5 mg·L–1 Cd for 4 days. Cd stress induced less random amplified polymorphism DNA (RAPD) polymorphism in LD10 than in SN20 roots, causing G1/S arrest in LD10 and G2/M arrest in SN20 roots. Virus-induced gene silencing (VIGS) of MLH1 in LD10-TRV-MLH1 plantlets showed markedly diminished G1/S arrest but enhanced root length/area under Cd stress. However, an increase in G1/S arrest and reduction of G2/M arrest occurred in SN20-TRV-MSH2 and SN20-TRV-MSH6 plantlets with decreased root length/area under Cd stress. Taken together, we conclude that the low expression of MSH2 and MSH6, involved in the G2/M arrest, results in Cd-induced DNA damage recognition bypassing the MMR system to activate G1/S arrest with the assistance of MLH1. This then leads to repressed root growth in LD10, explaining the intervarietal difference in Cd tolerance in soybean