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991.
992.
A Saccharomyces cerevisiae sequence cloned by serendipity was found to encode a protein that is a new member of the Ypt/Rab monomeric G-protein family. This sequence shows high homology to the yeast genes SEC4 and YPT1 and, like SEC4 and YPT1, is essential for viability. The sequence was localized to chromosome V based upon hybridization to pulse-field gel-separated yeast chromosomes. The sequence has been deposited in the GenBank data library under Accession Number L17070. 相似文献
993.
994.
F. Brossa A. Cigada R. Chiesa L. Paracchini C. Consonni 《Journal of materials science. Materials in medicine》1994,5(12):855-857
The purpose of this work is to evaluate the effects of post-deposition heat treatments on high and low crystallinity hydroxyapatite coatings on Ti6Al4V alloy. HA layers were produced by the vacuum plasma spray (VPS) technique, and the desired degrees of crystallinity were obtained by changing the deposition parameters. An analysis of the mechanical properties of the coatings and their adhesion to the substrate has been done by shear strength test. X-ray diffraction analysis was used to detect the structure and the chemical components in which HA dissociates during the deposition process and heat treatments. The data obtained indicates that heat treatments can increase the crystallinity of HA, but they also introduce a mechanical degradation of the coatings. After heat treatments, it was also observed that a large amount of tetracalcium phosphate was formed. 相似文献
995.
The extent of the dominant singular field is investigated for a finite crack under stress wave loading. Using a boundary integral equation method the complete solution as well as the near field solution is determined. A comparison of the two fields indicates that the singular field dominates within a small domain at the crack tip. The size of the dominance region in the dynamic case may be very different from that in the static case. 相似文献
996.
997.
The T1208 inventory in a HTR fuel element is transmuted from Th232. By measuring the T1208 gamma radiation in a suitable scan configuration it is possible to distinguish fuel elements with and without Thorium contents non-destructively even after a long cooling time. 相似文献
998.
H. R. Ott 《Journal of Low Temperature Physics》1994,95(1-2):95-108
Some of the most outstanding experimental evidences for unconventional superconductivity in heavy-electron materials are rewiewed and discussed. 相似文献
999.
A technique for evaluating the generation rare profile of MOS structures based on the measurement of gate current transients at two different gate voltage waveforms in non-equilibrium nonsteady-state is presented. The method allows the evaluation of the generation rate profile in the bulk of inhomogeneously doped MOS structures without requiring knowledge of the doping profile and provides, in contrast to high frequency methods, reliable results in such cases where MOS structures with high series resistances are to be investigated 相似文献
1000.
The Tikhonov regularisation technique is widely used in the solution of inverse scattering problems. One of the difficulties in applying this technique is the proper selection of the associated regularisation parameter. Based on a stochastic model of the reconstruction process, a simple method is presented for selecting this parameter for an efficient implementation of various microwave imaging methods 相似文献