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91.
This study investigates electromigration in Bi2Te3 thermoelectric (TE) material systems and the effectiveness of the diffusion barrier under current. The Peltier effect on the interfacial reaction was decoupled from the effect of electromigration. After connecting p- and n-type Bi2Te3 to Sn3Ag0.5Cu (SAC305) solders, different current densities were applied at varying temperatures. The Bi2Te3 samples were fabricated by the spark plasma sintering technique, and an electroless nickel-phosphorous (Ni-P) layer was deposited at the solder/TE interfaces. The experimental results confirm the importance of the Ni diffusion barrier in joint reliability. Intermetallic compound layers (Cu,Ni)6Sn5 and NiTe formed at the solder/Ni-P and Ni-P/substrate interfaces, respectively. The experimental results indicate that the mechanism of NiTe and (Cu,Ni)6Sn5 compound growth was dominated by the Peltier effect at high current density. When the current density was low, the growth of NiTe was affected by electromigration but the changes of thickness for (Cu,Ni)6Sn5 were not obvious. 相似文献
92.
93.
Siang Chen Wu Pi Fen Lu Yu Chien Lin Pei Chung Chen Chi Mei Lee 《International Journal of Hydrogen Energy》2012
Photobiological H2 production is a promising method for renewable energy development. An innovative system that co-cultivating Rhodopseudomonas palustris WP3-5 and Anabaena sp. CH3 was carried out to estimate the effect of co-cultivation on H2 production enhancement. H2 production prolongation and enhancement were observed due to the light and metabolic compatibility of these two strains. Co-culture system served by acetate and fructose as carbon source can accumulate H2 in 140.8 mL, almost double than the sum of individuals. Moreover, the enhancement of H2 production was significantly affected by the mixed ratio of two strains. The mixed ratio (WP3-5:CH3) of 1:2 showed a highest H2 production rate in 44.8 mL-H2/L-culture/h, and both 2:1 and 1:2 exhibited a relatively high substrate conversion efficiency during the latest period of cultivation, whereas the mixed ratio of 1:1 and 3:1 only revealed a prolongation in H2 production due to metabolic compatibility of two strains. 相似文献
94.
This study used ultrasonic scanning to investigate the contact between end-mill cutters and workpieces. This method is novel for endmills and has not been applied before. Contact shapes were disclosed and a comparison of contact images and areas was made from the experimental results. It is not a dynamic or online monitoring during the cutter machining process. Instead, it is only a static measurement because the objective is to provide the information for users to know the area size of a worn end-mill cutter. The 2D maps show an apparent change not only in area sizes but also in contact shapes for the used endmills. The 3D maps disclose the information for which region is in light or heavy contact. 相似文献
95.
On the Effect of Birefringence on Light Transmission in Polycrystalline Magnesium Fluoride 下载免费PDF全文
Light transmission in polycrystalline magnesium fluoride was studied as a function of the mean grain size at different wavelengths. The mean grain size was varied by annealing hot‐pressed billets in argon atmosphere at temperatures ranging from 600°C to 800°C for 1 h. The grain‐size and grain‐orientation distributions were characterized by electron back scatter diffraction. The scattering coefficients were calculated from the in‐line transmittance measured at various wavelengths. The scattering coefficient of polycrystalline magnesium fluoride increased linearly with the mean grain size and inversely with the square of the wavelength of light. It is shown that these trends are consistent with theoretical models based on both a limiting form of the Raleigh–Gans–Debye (RGD) theory of particle scattering and light retardation theories that take refractive index variations along the light path. Quantitative predictions of the theories are, however, subject to uncertainly due to the restrictive assumptions made in the theories and difficulties in representing the microstructure in the theoretical models. In particular, grain‐size distribution has a significant influence on the scattering coefficient calculated using particle scattering models. 相似文献
96.
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98.
Self‐Crack‐Filled Graphene Films by Metallic Nanoparticles for High‐Performance Graphene Heterojunction Solar Cells 下载免费PDF全文
99.
Enzyme‐Responsive Nanoparticles for Targeted Accumulation and Prolonged Retention in Heart Tissue after Myocardial Infarction 下载免费PDF全文
100.
Enhancing Optical Out‐Coupling of Organic Light‐Emitting Devices with Nanostructured Composite Electrodes Consisting of Indium Tin Oxide Nanomesh and Conducting Polymer 下载免费PDF全文