排序方式: 共有41条查询结果,搜索用时 15 毫秒
1.
KL Britton HF Rogers Y Asano T Dairi Y Kato TJ Stillman DW Rice 《Acta crystallographica. Section D, Biological crystallography》1998,53(4):124-126
The novel NAD+-linked opine dehydrogenase from a soil isolate Arthrobacter sp. strain 1C belongs to an enzyme superfamily whose members exhibit quite diverse substrate specificites. Crystals of this opine dehydrogenase, obtained in the presence or absence of co-factor and substrates, have been shown to diffract to beyond 1.8 ? resolution. X-ray precession photographs have established that the crystals belong to space group P21212, with cell parameters a = 104.9, b = 80.0, c = 45.5 ? and a single subunit in the asymmetric unit. The elucidation of the three-dimensional structure of this enzyme will provide a structural framework for this novel class of dehydrogenases to enable a comparison to be made with other enzyme families and also as the basis for mutagenesis experiments directed towards the production of natural and synthetic opine-type compounds containing two chiral centres. 相似文献
2.
An important material property in the paper industry is the anisotropic stiffness distribution due to the fibrous microstructure of paper and to processing procedures. Ultrasonic methods offer a means of determining the stiffness of sheets of paper from the anisotropic propagation characteristics of elastic Lamb waves along the machine direction and the cross direction. That is, along and perpendicular to the direction of paper production. Currently, piezoelectric ultrasonic methods are employed in the industry to measure the elastic polar diagram of paper through multiple contacting measurements made in all directions. This paper describes a new approach utilizing the INEEL Laser Ultrasonic Camera to provide a complete image of the elastic waves traveling in all directions in the plane of the paper sheet. This approach is based on optical dynamic holographic methods that record the out of plane ultrasonic motion over the entire paper surface simultaneously without scanning. The full-field imaging technique offers great potential for increasing the speed of the measurement and it ultimately provides a substantial amount of information concerning local property variations and flaws in the paper. This report shows the success of the method and the manner in which it yields the elastic polar diagram for the paper from the dispersive flexural or antisymmetric Lamb wave. 相似文献
3.
The focus of this presentation is to describe our efforts at laser generation of high frequency surface acoustic waves and detection of the nonlinear contribution in the acoustic near-field of the source. Narrow band acoustic generation is accomplished by interfering two pulsed laser beams at the surface of the sample. A Michelson interferometer, that incorporates a high power microscope objective, is used to detect the acoustic disturbance. Detection near the source combined with high frequency generation (approximately 0.1 GHz) facilitates investigation of fundamental processes of harmonic generation on length scales comparable to grain size dimensions. 相似文献
4.
Hildegard Telschow A. Kurtenacker H. Specker H. Sperlich K. Cruse B. Schühlein und K. Söllner 《Fresenius' Journal of Analytical Chemistry》1956,148(6):456-459
Ohne Zusammenfassung 相似文献
5.
6.
7.
Hildegard Telschow 《Fresenius' Journal of Analytical Chemistry》1956,149(3):231
Ohne Zusammenfassung 相似文献
8.
Hildegard Telschow 《Fresenius' Journal of Analytical Chemistry》1956,149(3):239
Ohne Zusammenfassung 相似文献
9.
Ohne Zusammenfassung 相似文献
10.
H. Specker K. Cruse Hildegard Telschow K. Brodersen J. Plank Th. Breyhan H. Sperlich K. Söllner K. Hinsberg und L. Acker 《Fresenius' Journal of Analytical Chemistry》1955,147(3):210-218
Ohne Zusammenfassung 相似文献