Microsystem Technologies - In this study, the discrete dipole approximation (DDA) method was used to simulate the hybrid bi-layer hexagonal lattice of triangular periodic nanoparticle arrays... 相似文献
The oxidation process of single-walled carbon nanotubes via nitric acid treatment was followed by IR-, UV-Vis-NIR, and single bundle Raman spectroscopy. The introduction of functional, oxygen-containing groups is revealed by an additional absorption band at 1725 cm−1, characteristic of carbonyl stretch vibrations. No significant shift of the optical absorption bands could be detected after oxidation. The combination of atomic force microscopy and confocal scanning resonance-enhanced Raman microscopy was used to investigate thin bundles and, eventually, individual nanotubes in detail. These experiments enabled determination of the dependence of the Raman intensity of the G-line (around 1590 cm−1) on the bundle height for both non-oxidized and oxidized tubes. The Raman cross-section of the oxidized tubes was found to be reduced by a factor of ˜4, compared to the pristine tubes. This observation is ascribed to all tubes within a bundle that are oxidized to the same degree. 相似文献
针对近年国内特高压直流输电工程中换流阀控制设备的实际运行工况,设计了一套完整的特高压直流输电工程阀控动模试验系统,整个试验系统包括整流侧换流阀、整流侧阀控(valve control equipment,VCE)、逆变侧换流阀、逆变侧VCE、控制与监视后台系统.该试验系统直接采用工程用晶闸管来搭建微型换流阀,相比实际工程用换流阀,减少了每个单阀的晶闸管数量,其他换流阀设计参数与实际工程相同,相较于采用实时数字仿真(real-time digital simulator,RTDS)系统模拟换流阀参数的方式,更有利于换流阀及输电线路参数的精确获取与处理,对阀控功能的验证更加有效.最后对许继集团研制的VCE800阀控系统进行了试验,验证结果表明该阀控动模试验系统可以满足特高压直流工程阀控设备联调需要. 相似文献
Purpose: To investigate the effects of phosphoric acid esters (PAEs)-containing primers on the micro-tensile bond strengths (MTBS) of etched enamel, the micro-morphologies of the resin–enamel interfaces, and the enamel surfaces.
Materials and Methods: Thirty-three bovine incisors were used in this study. After the labial enamel surfaces were highly polished, they were etched, water sprayed, and air-dried. Afterward, the enamel surfaces were treated with or without (control) one of three PAEs-containing primers (40%MDP, Ivoclar Vivadent; Resulcin AquaPrime A + B, DMG; Xeno V, Dentsply), water sprayed, and air-dried. Subsequently, an adhesive Heliobond (Ivoclar Vivadent) was applied and resin composite (Core Build-up, Bisco) was placed incrementally. They were prepared into multiple beams of about 1 × 1 × 8 mm for MTBS tests. The enamel surfaces and resin–enamel interfaces were analyzed by SEM and TEM. The data were analyzed by two-way ANOVA and LSD test.
Results: Using PAEs-containing primers could increase the enamel MTBS (p < 0.05). The primer MDP produced higher MTBS than the primer Resulcin AquaPrime A + B and Xeno V. The SEM findings revealed the primed enamel surfaces were covered with a thin or glue-like layer of monomer-calcium salts of PAEs and the residual enamel crystallites, and various micro-porosities were detected within the hybrid layers. The TEM findings revealed the hydroxyapatite crystallites were tightly covered by the adhesive, the adhesive mixed with resin composite, or sparse irregular enamel crystallites.
Conclusion: The application of PAEs-containing primers on the etched enamel substrate could significantly increase the immediate enamel bond strengths. However, this effect was dependent on the individual PAEs-containing primer used. 相似文献
Yb3+‐doped LuAG laser ceramics with different Yb3+‐doping concentrations were successfully fabricated by nonaqueous tape casting method and vacuum sintering technology. XRD patterns and SEM morphologies of the ceramics were presented. The optical in‐line transmittance of the Yb‐doped LuAG ceramics was about 83% at 1030 nm. The fluorescence lifetime of annealed and unannealed ceramic samples was compared. From the spectroscopic properties, it can be seen that the ceramics had a large emission cross section of 2.9 × 10?20 cm2 with a FWHM of about 7.2 nm at 1030 nm. Under 100% population inversion, the maximum gain coefficient was estimated to be 12.4 cm?1 at 1030 nm. With a fiber‐coupled diode laser as pump source, CW laser at 1030 nm was demonstrated and the maximum output power of 338.9 mW was achieved with a slop efficiency of 19%. A tuning range from 1028 to 1036 nm was obtained. 相似文献