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排序方式: 共有163条查询结果,搜索用时 15 毫秒
1.
Standard Gibbs free energy of formation (ΔGf0), an important property needed in design calculations has been estimated using molar refraction, RM. The linear relationships derived between ΔGf0 and RM tested with the data on 8 series of hydrocarbons at 228 compounds yielded average deviations comparable to the methods cited in recent literature. The method can be used as an alternative to the existing ones, because of its simplicity combined with reasonable accuracy. 相似文献
2.
Thin films of cadmium sulphide and cadmium telluride have been prepared by thermal evaporation under various conditions of deposition. These films have been characterized optically. electrically and for structure determination. The results of these characterizations along with the initial results of all thin film CdS/CdTe solar cells are presented in this paper 相似文献
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B Sagi S C Nemat-Nasser R Kerr R Hayek C Downing R Hecht-Nielsen 《Neural computation》2001,13(7):1575-1602
We present a new approach to the cocktail party problem that uses a cortronic artificial neural network architecture (Hecht-Nielsen, 1998) as the front end of a speech processing system. Our approach is novel in three important respects. First, our method assumes and exploits detailed knowledge of the signals we wish to attend to in the cocktail party environment. Second, our goal is to provide preprocessing in advance of a pattern recognition system rather than to separate one or more of the mixed sources explicitly. Third, the neural network model we employ is more biologically feasible than are most other approaches to the cocktail party problem. Although the focus here is on the cocktail party problem, the method presented in this study can be applied to other areas of information processing. 相似文献
5.
Maruf Hosssain Harry M. Meyer III Husam H. Abu-Safe Hameed A. Naseem William D. Brown 《Thin solid films》2006,510(1-2):184-190
The metal-induced crystallization (MIC) of hydrogenated sputtered amorphous silicon (a-Si:H) using aluminum has been investigated using X-ray diffraction (XRD) and scanning Auger microanalysis (SAM). Hydrogenated, as well as non-hydrogenated, amorphous silicon (a-Si) films were sputtered on glass substrates, then capped with a thin layer of Al. Following the depositions, the samples were annealed in the temperature range 200 °C to 400 °C for varying periods of time. Crystallization of the samples was confirmed by XRD. Non-hydrogenated films started to crystallize at 350 °C. On the other hand, crystallization of the samples with the highest hydrogen (H2) content initiated at 225 °C. Thus, the crystallization temperature is affected by the H2 content of the a-Si. Material structure following annealing was confirmed by SAM. In this paper, a comprehensive model for MIC of a-Si is developed based on these experimental results. 相似文献
6.
Farqad Al-Hadeethi Naseem Haddad Adi Said Hatem Alsyouri Amani Abdelhadi 《International Journal of Hydrogen Energy》2017,42(40):25558-25564
The world is facing a major problem due to the depletion of conventional energy sources. Hydrogen is considered one of the most promising sources of energy. Recently, one of the problems facing utilization of hydrogen energy is the storage. Therefore, finding materials to store hydrogen based on the adsorption/desorption methodology (i.e. metal hydrides) is considered extremely vital issue. During this work two candidate materials (i.e. Mg–H2 and LiNH2) were investigated at different temperatures (25–45 °C). The results revealed that both candidate materials possessed long cycle life and cyclibility which opens the wide door to use these materials in vehicular applications. On the other hand the generated mathematical models based on the multiple regression analysis with respect to ANOVA showed that increasing temperature will increase the weight of hydrogen adsorption for both candidate materials. 相似文献
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We have prepared Nb thin films with e-beam evaporation under UHV conditions. Al thin films were deposited by resistive heating in the UHV chamber. The preparation of these films and the tri-layers of Nb/AlOx/Nb were intended for their use in Josephson junctions. The surface studies of these films were undertaken by using scanning electron microscope and atomic force microscope in the non-contact mode, whilst the interface analysis was carried out by depth profiling using scanning Auger microprobe. These studies have revealed that Nb films grown on AlOx are smoother than the ones grown on Si. Further, it is seen that Al diffuses into Nb on both sides and that the interface is very broad. This intermixing of various materials results in the failure of the tri-layers when subjected to application in SQUIDs. 相似文献
9.
The absolute wavenumbers for 36 lines of the 3-0 band of 12C16O are measured from P(17) at 6271 cm-1 to R(19) at 6405 cm-1, with an uncertainty of about +/-3 x 10(-5) cm-1 (about +/-1 MHz). The experimental positions are compared with the best predicted positions from recent Dunham coefficients. Self-induced pressure lineshifts are determined and reach, at most, about -8 x 10(-3) cm-1 atm-1. Copyright 1997 Academic Press. Copyright 1997Academic Press 相似文献
10.
Shape memory polymer nanocomposites 总被引:7,自引:0,他引:7
Ken Gall Martin L. Dunn Yiping Liu Dudley Finch Mark Lake Naseem A. Munshi 《Acta Materialia》2002,50(20):5115-5126
The paper describes the fabrication and characterization of composites with a shape memory polymer matrix and SiC nanoparticulate reinforcements. Composites based on a SMP matrix are active materials capable of recovering relatively large mechanical strains due to the application of heat. The composites were synthesized from a commercial shape memory polymer resin system and particulate SiC with an average diameter of 300 nm. Composites with weight fractions of 10%, 20%, 30%, and 40% nanoparticulate SiC were fabricated by casting samples with sizes ranging from a few hundred microns to several millimeters. The former size scale is consistent with a microcasting process for manufacturing microelectomechanical systems. The micro-hardness and elastic modulus of the nanocomposites increased by approximately a factor of 3 with the addition of 40 wt% SiC into the base resin. Unconstrained strain recoverability of the nanocomposites was found to depend on the fraction of SiC. For 180° bend tests, the recoverability of the nanocomposites was perfect for SiC weight fractions below 40%. For 40 wt% SiC, permanent bend strains were discovered. Constrained bending recovery force in the nanocomposites was shown to increase by 50% with the addition of 20 wt% SiC. 相似文献