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861.
J.F. Payne 《Marine pollution bulletin》1977,8(5):112-116
Several phyla from the coastal Northwest Atlantic were investigated for mixed function oxidases. Enzyme activity was related to petroleum hydrocarbon metabolism and detection in the marine environment. 相似文献
862.
863.
The paper presents a continuum method for dynamic analysis of asymmetric tall buildings with uniform cross-section in which the horizontal stiffness is provided by shear walls and columns of arbitrary shape and layout, coupled by horizontal beams. The equations of motions are formulated in variational terms, including axial strain energy. Numerical solutions, obtained by using finite time differences and infinite polynomials, are presented for the response of a twenty-storey building with six shear walls to an impact load and earthquake accelerations. It is shown that omission of the axial deformations results in a substantially distorted pattern of behaviour, some of its effects being:
- 1 Overestimation of the bending stiffness of the coupled shear walls, with corresponding changes in their stiffness ratios.
- 2 Underestimation of the periods of the principal modes, with a corresponding change in the dynamic response.
- 3 Distortion of the magnitude, form, time of onset and coupling of the maximum displacements.
- 4 Pronounced change in the shear force and moment diagrams for the shear walls, the beams and the building as a whole.
864.
The development of an alkali vapour vehicle borne magnetometer providing very high resolution and a high sampling rate has called for reconsideration of interpretation procedures. With continuous profiling at ground level, the close proximity to near surface structures requires that the precise interpretation of geological boundaries be of paramount importance. Rapid digital recording also demands efficient data processing. Both these requirements can be met by the method described. Essentially the method reduces to a simple Hilbert transform of the magnetic profile. The calculation provides an extremely well defined position of the contact and accurate specification of the dip, strike, depth of overburden, and magnetic susceptibility parameters. Particular advantages are tolerance to high frequency noise, independence from a predetermined origin and baseline, and freedom from subjective judgements. 相似文献
865.
866.
Many hydrothermal deposits are formed around the marine and terrestrial fumarolic vents of Vulcano island (Italy). Their genesis is related to the recombination of the elements brougth by the fumaroles and those liberated by the destruction of pre-existing minerals. 相似文献
867.
F. Zebender P. Zimmermann R. Märki A. Hörler H. Ambübl 《Aquatic Sciences - Research Across Boundaries》1961,23(1):296-308
Ohne Zusammenfassung 相似文献
868.
869.
870.
Mini-sosie consists in using a vibration-rammer as seismic source and changing the striking rate by varying the engine speed, resulting in a random impulse transmission. The recording instruments are made up of two seismic traces, two constant gain amplifiers and a two-channel sosie processor which performs the decoding in real time by using the actual transmission times supplied by a captor located on top of the vibration-rammer's plate. An idea of the possible penetration is given by the recording of a velocity survey. Other results obtained in seismic reflection and refraction are given. 相似文献