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41.
Li-Chung Wu Dong-Jiing Doong Chia Chuen Kao 《International journal of remote sensing》2013,34(5):1303-1318
In this study, a two-dimensional continuous wavelet transform is applied to quantify the non-homogeneity from remote-sensing wave images. Our study shows that the non-homogeneity index, which is proposed here, is capable of identifying the degree of non-homogeneity from the wave-field images. However, the influence from the edges of the wave-field image should be considered in analysis. The calculated results from the simulated wave fields and from the natural wave-field images reveal that the non-homogeneity index is influenced by the bathymetry inside the area of the ocean-wave image. It conforms to the character of the natural wave non-homogeneity. After discussing the wave characteristics from the wave-field image with a high non-homogeneity index, an inhomogeneous algorithm is recommended for obtaining accurate and reasonable wave results from the wave image. 相似文献
42.
Investigation of growth behavior of Al-Cu intermetallic compounds in Cu wire bonding 总被引:1,自引:0,他引:1
In this work, we investigate the intermetallic compound formation in Cu wire bonded device. Voids near the Cu side at the bond interface are clearly seen. Nevertheless, these voids do not seem to interfere with the function of the unit. High temperature storage test (HTST) results show that there are Al2Cu and AlCu in the damaged unit while Al2Cu and Al4Cu9 appear in the good unit. The results clearly show that the Al layer is exhausted in the damaged unit while those with Al4Cu9 on the Cu side pass HTST with unconsumed Al. Theoretical calculations indicate that AlCu and Al4Cu9 are energetically more favorable than Al2Cu, which is consistent with the reported IMC forming sequence. Formation energy of AlCu is compatible but slightly lower to that of Al4Cu9, suggesting AlCu tends to be the most stable phase among all. The reason why the Al layer is completely consumed in one case and some Al layer remains in the other is due to the fact that the formation of AlCu requires more than twice the amount of Al than Al4Cu9 for the same amount of Cu consumed. The complete consumption of Al is proposed as the reason responsible for the failure of the damaged unit. 相似文献
43.
W. T. Lee S. X. Ding D. K. Sun C. I. Hsiao C. P. Chang L. Chang P. W. Kao 《Metallurgical and Materials Transactions A》2011,42(9):2909-2916
Ultrafine-grained (UFG) Mg-3Al-1Zn (AZ31) alloys with gain sizes ranging from 0.46 to 3.22 μm were prepared by equal channel angular pressing (ECAP) and annealing. The deformation structure of UFG AZ31 alloy resulting from uniaxial compression was studied by optical and electron microscopy. The deformation was noted to proceed with the development of shear bands (SBs), which has not been reported in an UFG hcp metal. Characterization of these SBs was performed, and comparison with the SBs formed in UFG bcc and fcc metals was given. { 10[`1]2} { 10bar{1}2} tension twins inside SBs were found in all specimens compressed, irrespective of the grain size. Discussion on the limiting grain size of twinning in the UFG AZ31 alloy is also given. 相似文献
44.
Planar Heterojunction Perovskite Solar Cells Incorporating Metal–Organic Framework Nanocrystals 下载免费PDF全文
45.
HM, an HMG1-like mitochondrial DNA-binding protein, is required for maintenance of the yeast mitochondrial genome when cells are grown in glucose. To better understand the role of HM in mitochondria, we have isolated several multicopy suppressors of the temperature-sensitive defect associated with an abf2 null mutation (lacking HM protein). One of these suppressors, SHM1, has been characterized at the molecular level and is described herein. SHM1 encodes a protein (SHM1p) that shares sequence similarity to a family of mitochondrial carrier proteins. On glycerol medium, where mitochondrial function is required for growth, shm1 deletion mutants are able to grow, whereas shm1 abf2 double mutants are severely inhibited. These results suggest that SHM1p plays an accessory role to HM in the mitochondrion. The GenBank Accession Number for the SHM1 sequence is U08352. 相似文献
46.
47.
Liao Shih-Wei Kuang Shao-Yun Kao Chia-Lung Tu Chia-Heng 《Journal of Signal Processing Systems》2019,91(3-4):219-233
Journal of Signal Processing Systems - New programming models have been developed to embrace contemporary heterogeneous machines, each of which may contain several types of processors, e.g., CPUs,... 相似文献
48.
Staphylococcus aureus is a pathogen important in causing human infections and intoxication. A sensitive fiber-optic that produces evanescent waves was developed for the detection of protein A, a product secreted only by S. aureus. In the immunosensor, a 40-mV argon-ion laser that generated laser light at 488 nm was used together with plastic optical fiber and antibodies to protein A were physically adsorbed onto the fiber. The principle of the detection involved a sandwich immunoassay with fluorescein isothiocyanate conjugated with anti-(protein A) immunoglobulin G to produce signals of the antigen-antibody reaction. The detection limit was 1 ng of protein A per milliliter. The fiber-optic immunosensor could be used for rapid and specific detection of S. aureus in clinical specimens and foods. 相似文献
49.
This paper is concerned with the flow behavior of isotropic solutions of the rod-like polymer, poly(p-phenyleneterephthalamide) (PPT), in 100 percent sulfuric acid. Studies include entry flow visualization in a slit die and solution fracture, and die swell in capillaries and a slit die. It was observed that solutions of PPT exhibit nearly negligible die swell, a slip-stick type of fracture that disappears at high shear rates, and radial entry flow patterns similar to Newtonian fluids. Fracture was associated with the plateau in the shear stress vs shear rate curve. Because values of the wall shear stress (τw.) obtained from capillary measurements were in good agreement with those obtained from a cone-and-plate rheometer and values of the loss modulus (G″) obtained from small-strain dynamic oscillatory measurements, it is believed that the rheological properties lead to the flow instability. These results are in agreement with the predictions of a recent theory by Doi and Edwards for concentrated solutions of rod-like molecules. Data are also presented for a flexible chain polyamide, nylon 6,6, in 100 percent H2SO4 for the purpose of comparing the flow characteristics of rigid and flexible chain polymers. 相似文献
50.
Chemical characterization of the mutagenic neutral aromatic polar fractions of petroleum substitutes
The constituents of the neutral aromatic polar subfractions of two coal-derived oils, a shale-derived oil and a petroleum oil were analysed and compared. Chemical ionization mass spectra, using methanol and ammonia as reagent gases, were used to characterize the oxygen-and nitrogen-containing constituents, respectively. The compositions of the petroleum substitutes were found to differ from those of petroleum in containing primary polycyclic aromatic amines, azaarenes, polycyclic hydroxyaromatics and, in one case, aromatic ketones. 相似文献