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Klaus Keil Benton C. Clark A. K. Baird Priestley Toulmin III Harry J. Rose Jr. 《Die Naturwissenschaften》1978,65(5):231-238
Analyses of 13 samples of Martian surface materials with the Viking X-ray fluorescence spectrometers show SiO2 similar to that of terrestrial mafic rocks, whereas Fe2O3, Cl, and S are higher and Al2O3, K2O, Rb, Sr, Y, and Zr are lower. Low totals suggest presence of CO2, H2O, and Na2O. Duricrust fragments are higher in S than fines, but samples from both landing sites are surprisingly similar. We suggest that Martian surface materials are aeolian deposits of complex mixtures of weathering products of maficultramafic rocks, possibly consisting of iron-rich clays, sulfates, iron oxides, carbonates, and chlorides. 相似文献
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Philipp Balzer Klaus Peter Rippe Peter Schaber 《Journal of Agricultural and Environmental Ethics》2000,13(1):7-27
The 1992 incorporation of an article by referendum in the SwissConstitution mandating that the federal government issue regulations onthe use of genetic material that take into account the dignity ofnonhuman organism raises philosophical questions about how we shouldunderstand what is meant by ``the dignity of nonhuman animals,' andabout what sort of moral demands arise from recognizing this dignitywith respect to their genetic engineering. The first step in determiningwhat is meant is to clarify the difference between dignity when appliedto humans and when applied to nonhumans. Several conceptions of humandignity should be rejected in favor of a fourth conception: the rightnot to be degraded. This right implies that those who have it have thecognitive capacities that are prerequisite for self-respect. In the caseof nonhuman organisms that lack this capacity, respecting their dignityrequires the recognition that their inherent value, which is tied totheir abilities to pursue their own good, be respected. This value isnot absolute, as it is in the case of humans, so it does not prohibitbreeding manipulations that make organisms more useful to humans. But itdoes restrict morally how sentient animals can be used. In regard togenetic engineering, this conception requires that animals be allowedthe uninhibited development of species specific functions, a positionshared by Holland and Attfield, as opposed to the Original Purposeconception proposed by Fox and the Integrity of the Genetic Make-upposition proposed by Rolston. The inherent value conception of dignity,as here defended, is what is meant in the Swiss Constitution article. 相似文献
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Werner von Bloh Christine Bounama Klaus EisenackBrigitte Knopf Oliver Walkenhorst 《Ecological modelling》2008
To determine the influence of the biosphere on weathering we use a dynamic model of the global carbon cycle. It takes into account the most important processes for the long-term evolution of the Earth. The model is solved under a slowly changing environment of increasing solar luminosity and volcanic activity and continental area. By comparing the model results for the global average temperature with data derived from δ18O values from cherts it is possible to quantify the biogenic enhancement factor of weathering. For this purpose a newly developed inverse viability method is applied, which allows for calculating the range of possible biogenic enhancement factors consistent with the data. We find that in the Precambrian the weathering was 5.4 times lower than in the Phanerozoic era. This supports the hypothesis that the Cambrian explosion was caused by a positive feedback between the spread of biosphere, increased silicate weathering, and a consequent cooling of the climate. 相似文献