Schottky barrier formation and band bending revealed by first principles calculations

An atomistic insight into potential barrier formation and band bending at the interface between a metal and an n-type semiconductor is achieved by ab initio simulations and model analysis of a prototype Schottky diode, i.e., niobium doped rutile titania in contact with gold (Au/Nb:TiO$_2$). The local Schottky barrier height is found to vary between 0 and 1.26 eV depending on the position of the dopant. The band bending is caused by a dopant induced dipole field between the interface and the dopant site, whereas the pristine Au/TiO$_2$ interface does not show any band bending. These findings open the possibility for atomic scale optimization of the Schottky barrier and light harvesting in metal-semiconductor nanostructures

Symmetry-dependent screening of surface plasmons in ultrathin supported films: The case of Al/Si(111)

A joint theoretical and experimental study of plasmon excitations for Al overlayers on Si(111) has been carried out. The presence of the substrate is found to drastically modify the hybridization and charge density response of the surface plasmons of the metal overlayers. The symmetric mode, which is polarized toward the Al/Si interface, is strongly damped in intensity and significantly redshifted in energy. However, the antisymmetric mode, which is polarized to the metal-vacuum interface, is essentially unaffected by the presence of the substrate. A low-energy acoustic plasmon mode is also found in a one monolayer Al film and is almost unaffected by the substrate. The calculated plasmon dispersions with substrate are in good agreement with experimental data measured by electron energy loss spectroscopy. Our results suggest that interaction and screening at the subnanometer scale are symmetry dependent, a conclusion that may have general implications in other thin films and related structures

A Real-time Non-contact Localization Method for Faulty Electric Energy Storage Components using Highly Sensitive Magnetometers

With the wide application of electric energy storage component arrays, such as battery arrays, capacitor arrays, inductor arrays, their potential safety risks have gradually drawn the public attention. However, existing technologies cannot meet the needs of non-contact and real-time diagnosis for faulty components inside these massive arrays. To solve this problem, this paper proposes a new method based on the beamforming spatial filtering algorithm to precisely locate the faulty components within the arrays in real-time. The method uses highly sensitive magnetometers to collect the magnetic signals from energy storage component arrays, without damaging or even contacting any component. The experimental results demonstrate the potential of the proposed method in securing energy storage component arrays. Within an imaging area of 80 mm $\times$ 80 mm, the one faulty component out of nine total components can be localized with an accuracy of 0.72 mm for capacitor arrays and 1.60 mm for battery arrays

Quantum plasmonics: Symmetry-dependent plasmon-molecule coupling and quantized photoconductances

We investigate photoinduced electron transport through nanoparticle dimers connected by linear and ringlike molecules. The two model junctions exhibit similar absorption but distinct photoconductance. The linear-chain junction shows a constant conductance that is independent of photon energies. In contrast, the ring molecules show quantized conductance resonances at energies corresponding to the molecular excitations. These results can be understood from the symmetry and quantization of local molecular excitations, and have implications for plasmon-molecule interactions in general

Path Integral Treatment of Proton Transport Processes in BaZrO3

Nuclear quantum effects on proton transfer and reorientation in BaZrO3 is investigated theoretically using the ab initio path-integral molecular-dynamics simulation technique. The result demonstrates that adding quantum fluctuations has a large effect on, in particular, the transfer barrier. The corresponding rates and diffusion coefficient are evaluated using the path-centroid transition state theory. In contrast with what is found assuming classical mechanics for the nuclear motion, the reorientation step becomes rate limiting below 600 K

The Physiological and Agronomic Responses to Nitrogen Dosage in Different Sugarcane Varieties

Nitrogen (N) is very important for sugarcane yield improvement, but the excessive application of N fertilizer brings about N pollution and a cost increase. Through distinguishing the difference of nitrogen use efficiency (NUE), we can reasonably apply N fertilizer according to the NUE characteristics of sugarcane varieties, and thus reduce N loss and maintain high yield. The present study showed the pot experiment results of identifying NUE types of nine main sugarcane varieties in the main sugarcane producing areas of China under controlled conditions, and identified the key physiological and agronomic indictors which can help to determine the NUE types of sugarcane. The test clones were exposed to varying levels of N fertilizer and 15 parameters that are likely to impact NUE were measured. The key results are (1) Sugarcane variety ROC22 has the high plant dry weight (PDW) and NUE among nine varieties under different N rates, it can take advantages under low N supply (225 kg/hm2 urea), and less N fertilizer can be applied properly in production. (2) Varieties of GT32 was good performing genotype for PDW and NUE under low N supply (225 kg/hm2 urea), GT42 was more suitable for moderate N environment (450 kg/hm2 urea), while YT94-128 was at middle N and high N supply (450–675 kg/hm2 urea). (3) Late stage of shoot elongation is suitable for differentiating sugarcane clones for NUE. (4) Leaf glutamine synthetase activity is the most reliable predictor of NUE in sugarcane. The result of pot experiment is sufficient to differentiate clonal variation for NUE in sugarcane as it reflects field experimental results. This study can set up a basis for identification the NUE types of sugarcane varieties and the development of reasonable N fertilizer application

Heterologous expression of a Glyoxalase I gene from sugarcane confers tolerance to several environmental stresses in bacteria

Glyoxalase I belongs to the glyoxalase system that detoxifies methylglyoxal (MG), a cytotoxic by-product produced mainly from triose phosphates. The concentration of MG increases rapidly under stress conditions. In this study, a novel glyoxalase I gene, designated as SoGloI was identified from sugarcane. SoGloI had a size of 1,091 bp with one open reading frame (ORF) of 885 bp encoding a protein of 294 amino acids. SoGloI was predicted as a Ni2+-dependent GLOI protein with two typical glyoxalase domains at positions 28–149 and 159–283, respectively. SoGloI was cloned into an expression plasmid vector, and the Trx-His-S-tag SoGloI protein produced in Escherichia coli was about 51 kDa. The recombinant E. coli cells expressing SoGloI compared to the control grew faster and tolerated higher concentrations of NaCl, CuCl2, CdCl2, or ZnSO4. SoGloI ubiquitously expressed in various sugarcane tissues. The expression was up-regulated under the treatments of NaCl, CuCl2, CdCl2, ZnSO4 and abscisic acid (ABA), or under simulated biotic stress conditions upon exposure to salicylic acid (SA) and methyl jasmonate (MeJA). SoGloI activity steadily increased when sugarcane was subjected to NaCl, CuCl2, CdCl2, or ZnSO4 treatments. Sub-cellular observations indicated that the SoGloI protein was located in both cytosol and nucleus. These results suggest that the SoGloI gene may play an important role in sugarcane’s response to various biotic and abiotic stresses