Effect of dipole location on profile properties of symmetric surface plasmon polariton mode in Au/Al2O3/Au waveguide

This study uses a dipole embedded in A1203 layer to excite a symmetric surface plasmon polariton （SPP） mode in Au/A1203/Au waveguide to investigate its profile properties by using finite-difference time-domain （FDTD） method. The excited dipole decay radiatively direct near-field coupling to SPP mode owing to thin A1203 layer of 100 nm. The effects of electric and magnetic field intensity profiles and decay length have been considered and characterized. It is found that dipole location is an important factor to influence the horizontal and vertical profile properties of symmetric SPP mode in Au/A1203/Au waveguide. The amplitudes of electric and magnetic field intensity and the wavelengths of metal-insulatormetal （MIM） SPP resonance mode can be tuned by varying dipole location. The horizontal and vertical decay lengths are 19 and 24 nm, respectively. It is expected that the Au/A1203/Au waveguide structure is very useful for the practical applications of designing a SPP source.

Internal Friction and Profile of Property and Structure of PD_3 and PD_3RE Rail Steels

The profile of both hardness and microstructure of continuous casting blanks and rails of PD3 heavy rail steel and PD3RE steel containing small amount of rare earth （RE） added from tundish were studied. It is found that the addition of RE makes the fluctuation of the hardness value decrease, and inhibits effectively and/or even removes lower hardness value（zone） in the centric area of the blank with a cross section of 280 mm × 380 mm, and that the surface layer in the rail head of PD3RE steel is obviously hardened and the reason causing this hardening is due to the thinning of the pearlite structure. The metallographic observation shows that there exists a Fe-P（C） eutectic structure in the blank center of the PD3 steel containing only 0. 016% P, while the addition of RE can fully inhibit this structure.

Effects of total replacement of corn silage with sorghum silage on milk yield,composition, and quality

Background： In the last years, difficulties occurring in corn cultivation（i.e., groundwater shortages, mycotoxin contamination） have been forcing dairy farmers to consider alternative silages. Some experiments conducted on lactating cows have proven that the total replacement of corn silage with sorghum silage did not reduce milk yield.However, this kind of substitution involves supplementing sorghum-based diets with grains, to compensate for the lower starch content of sorghum silage compared to corn silage. Change of silage type and inclusion of starch sources in the diet would influence rumen fermentations, with possible effects on milk composition（i.e., fatty acid profile） and coagulation properties. A worsening of milk coagulation properties would have a negative economic impact in Italy, where most of the milk produced is processed into cheese.This study was designed to compare milk composition and quality, with emphasis on fatty acid profile and coagulation properties, in dairy cows fed two diets based on corn or sorghum silage.Results： The sorghum diet reduced milk yield（P = 0.043） but not 4% fat corrected milk（P = 0.85）. Feeding sorghum silage did not influence milk contents of protein（P = 0.07） and lactose（P = 0.65）, and increased fat content（P = 0.024）.No differences emerged for milk concentrations of saturated（P = 0.61） and monounsaturated fatty acids（P = 0.50）,whereas polyunsaturated fatty acids were lower（P 〈 0.001） for the sorghum diet. Concentrations of n-6（P 〈 0.001） and n-3 fatty acids（P = 0.017） were lower in milk of cows fed the sorghum diet. Milk coagulation properties did not differ between the two diets, except the ＂a30＂（the curd firmness, expressed in mm, 30 min after rennet addition）, that was lower（P = 0.042） for the sorghum diet.Conclusions： Feeding a forage sorghum silage, properly supplemented with corn meal, as total replacement of corn silage maintained milk composition and did not influence negatively milk coagulation properties, which have a great economic relevance for the Italian dairy industry. Thus, silages obtained from forage sorghums could have a potential as substitute of corn silages in dairy cow diets.

Electrical transport and current properties of rare-earth dysprosium Schottky electrode on p-type GaN at various annealing temperatures

The electrical and current transport properties of rapidly annealed Dy/p-GaN SBD are probed by I-V and C-V techniques. The estimated barrier heights（BH） of as-deposited and 200 ℃ annealed SBDs are 0.80 eV（I-V）/0.93 eV（C-V） and 0.87 eV（I-V）/1.03 eV（C-V）. However, the BH rises to 0.99 eV（I-V）/1.18 eV（C-V）and then slightly deceases to 0.92 eV（I-V）/1.03 eV（C-V） after annealing at 300 ℃ and 400 ℃. The utmost BH is attained after annealing at 300 ℃ and thus the optimum annealing for SBD is 300 ℃. By applying Cheung＇s functions, the series resistance of the SBD is estimated. The BHs estimated by I-V, Cheung＇s and ΨS-V plot are closely matched; hence the techniques used here are consistency and validity. The interface state density of the as-deposited and annealed contacts are calculated and we found that the NSS decreases up to 300 ℃ annealing and then slightly increases after annealing at 400 ℃. Analysis indicates that ohmic and space charge limited conduction mechanisms are found at low and higher voltages in forward-bias irrespective of annealing temperatures. Our experimental results demonstrate that the Poole-Frenkel emission is leading under the reverse bias of Dy/p-GaN SBD at all annealing temperatures.

In-situ generation and global property profiling of metal nanoclusters by ultraviolet laser dissociation-mass spectrometry

Metal nanoclusters are promising nanomaterials with unique properties, but only a few ones with specific numbers of metal atoms can be obtained and studied up to now. In this study, we establish a new paradigm of in-situ generation and global study of metal nanoclusters with different sizes, constitutions, and charge states, including both accurate constitution characterization and global activity profiling. The complex mixtures of metal nanoclusters are produced by employing single-pulsed 193-nm laser dissociation of monolayer-protected cluster(MPC) precursors within a high-resolution mass spectrometry(HRMS). More than400 types of bare gold nanoclusters including novel multiply charged(2+ and 3+), S-/P-doped, and silver alloy ones can be efficiently generated and accurately characterized. A distinct size(1 to 142 atoms)-and charge(1+ to 3+)-hierarchy reactivity is clearly observed for the first time. This global cluster study might greatly promote the developments and applications of novel metal nanoclusters.