Effective Photoinactivation of Alpha‐Amylase,Catalase and Urease at 222 nm Emitted by an KrCl‐Excimer Lamp     

Marcus Clauß  Norbert Grotjohann 《洁净——土壤、空气、水》2008,36(9):754-759

The inactivation of enzymes is of great interest for many industrial applications. The effectiveness of photoinactivation of alpha‐amylase, catalase, and urease with 222 nm radiation was investigated in comparison to that at 254 nm. The enzymes were irradiated with different fluence rates of 222 nm radiation emitted by a KrCl‐excimer lamp and with 254 nm radiation produced by a low‐pressure mercury lamp. The relative activities were calculated before and after irradiation. Degradation caused by UV‐radiation was assessed by SDS‐PAGE analysis. The results clearly demonstrated that inactivation of the proteins is much more effective with the 222 nm excimer lamp compared to the 254 nm mercury lamp. Irradiation with the excimer lamp and a UV‐fluence rate of 1000 J/m² was sufficient to reduce the relative activities of amylase and urease to 15% and that of catalase to 60%. After irradiation with 4000 J/m², the enzyme activity was almost completely inhibited. In contrast, after irradiation with the mercury lamp with an UV‐fluence rate of 4000 J/m², the relative activity was still above 85%. The gel patterns showed no visible degradation after irradiation at 254 nm, but a strong and unspecific degradation was obvious after treatment at 222 nm, presumably caused by cleavage of the peptide bonds.  相似文献   

40Ar-39Ar ages of Dellen,Jänisjärvi,and Sääksjärvi impact craters     

Norbert Müller  Jack B. Hartung  Elmar K. Jessberger  Wolf U. Reimold 《Meteoritics & planetary science》1990,25(1):1-10

Abstract— ⁴⁰Ar-³⁹Ar age measurements were made for three whole rock melt samples produced during impact events which formed the Dellen, Jänisjärvi, and Sääksjärvi craters on the Baltic Shield. An age of 109.6 ± 1.0 Ma was obtained for the Dellen sample based on an age spectrum plateau. The age spectrum shows a small (7%) loss of radiogenic ⁴⁰Ar from low temperature fractions. Ages of 698 ± 22 Ma and 560 ± 12 Ma were obtained from isochrons for the Jänisjärvi and Sääksjärvi samples, respectively. Data obtained by laser degassing support the Sääksjärvi result. The presence of excess ⁴⁰Ar is indicated in lower temperature fractions for both samples and is correlated with K concentrations in the Sääksjärvi sample. Models explaining these results may require a change in the local “atmospheric” Ar isotopic composition as cooling of melt rocks proceeded. However, it cannot be excluded that devitrification and/or alteration changed the Ar budget. A crater production rate on the Baltic Shield based on measured ages of 6 craters is (0.3 ± 0.2) · 10^?14 20-km-and-larger craters per km² per year, in satisfactory agreement with previous estimates.  相似文献   

Utilisation de la methode rubidium-strontium pour la datation d'une schistosite de sediments peu metamorphises: Application au Precambrien II de la boutonniere de Bou Azzer-El Graara (Anti-Atlas,Maroc)     

Norbert Clauer 《Earth and Planetary Science Letters》1974,22(4):404-412

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Multimethod (K–Ar, Rb–Sr, Sm–Nd) dating of bentonite minerals from the eastern United States     

Theofilos Toulkeridis  Norbert Clauer  Sam Chaudhuri  & Steve L. Goldstein 《Basin Research》1998,10(2):261-270

Isotopic determinations (K–Ar, Rb–Sr and Sm–Nd), and trace and rare-earth elemental analyses were made on a few biotite and clay fractions of Palaeozoic bentonite units from the eastern United States. The clay fractions were gently leached with dilute hydrochloric acid to study separately the acid-soluble minerals intimately associated with the extracted clay particles. The data highlight interesting potentials for this integrated approach to decipher complex tectonothermal evolutions of sedimentary basins. Biotite K–Ar ages are consistent with a Middle Ordovician stratigraphic age for the bentonite units with a mean age of 459±10 Ma. The clay residues give a Sm–Nd isochron age of 397±44 Ma, indicative of their crystallization during Acadian tectonothermal activity at about 200 °C. The clay leachates, which are considered to represent mineral phases different from clay material, yield a distinct Sm–Nd isochron age of 285±18 Ma which is indistinguishable from K–Ar ages obtained previously on the clays, suggesting a thermally induced diffusion of radiogenic ⁴⁰Ar from clay particles during Alleghenian–Ouachita orogenic activity. The Rb–Sr system of the clay material seems to have been variably disturbed, except for the sample taken near the Allegheny Front for which an age of 179±4 Ma suggests a further localized activity of the thrust system at about 130–150 °C. Clearly the limited number of samples does not allow us to perfectly constrain an evolutionary model. However, analysis of the soluble minerals for their contents in metal and rare-earth elements suggests that metal-carrying fluids migrated during the Alleghenian–Ouachita orogenic activity in the eastern North American continent. Consequently, they could have contributed to the concentration of ore deposits in the region, but this possibility needs to be tested with a larger data base.  相似文献   

Micro-autoradiographic determination of the viability of algae inhabiting deep sediment layers     

Norbert Wasmund 《Estuarine, Coastal and Shelf Science》1989,28(6)

Examination of sediment cores taken from shallow coastal regions of the Baltic showed that some algae were still alive at depths beyond the depth of light penetration. Their cells contained chlorophyll and photosynthesis resumed when they were exposed to light. Photosynthesis was detected by simultaneous measurement of oxygen production and ¹⁴C uptake. Autoradiography was used to detect incorporated ¹⁴C. The autoradiographic method was improved by a few modifications.  相似文献   

Precise orbit determination based on raw GPS measurements   总被引：1，自引：0，他引：1  

Norbert Zehentner  Torsten Mayer-Gürr 《Journal of Geodesy》2016,90(3):275-286

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Development and application of a quantitative risk assessment to a very slow moving rock slope and potential sudden acceleration     

Renato Macciotta  C. Derek Martin  Norbert R. Morgenstern  David M. Cruden 《Landslides》2016,13(4):765-785

The benefits of quantitative risk assessments for landslide management have been discussed and illustrated in several publications. However, there still are some challenges in its application for low-probability, high-magnitude events. These challenges are associated with the difficulties in populating our models for risk calculations, which largely require the input of expert opinion. This paper presents a quantitative risk assessment to a very slow moving rock slope within a dam reservoir in the Province of British Columbia, Canada. The assessment is focused on the risk to the population in the vicinity of the dam and the populated areas downstream. Expert opinions quantified the slope failure probabilities in the order of 10^?3 to 10^?1 per year for the smallest failure scenario considered and less than 10^?6 for a failure of the entire slope. However, these estimations are associated with high levels of uncertainty. Our approach starts with the calculation and assessment of the magnitude and probability of the potential slope failure consequences, minimizing the uncertainties associated with estimated slope failure probabilities. Then, these consequences and failure probabilities are combined to obtain a measure of risk. The uncertainty associated with the slope failure probabilities is managed by the estimation of plausible ranges for these. The calculated risk levels are then presented as ranges of values and assessed against adopted evaluation criteria. The consequence and risk assessment of the rock slope suggest that the risk to the population exposed in the vicinity of the dam and populated areas downstream is under adequate control. The probability of large consequence scenarios is extremely low, in the order of 10^?7 chance of an event causing more than 100 fatalities. We propose an observational technique to assess changes in risk levels and decide when to update the risk management approach or deploy emergency measures. The technique is focused on the detection of changes in the slope deformation patterns that would indicate an increase in the potential failure volumes or an imminent failure. It can be considered an extension to the current early warning system in place, easy to implement and enhanced with the strength of the comprehensive analysis required for a quantitative risk assessment.  相似文献   

Parádsasvárite,a new member of the malachite-rosasite group from Parádsasvár,Mátra Mountains,Hungary     

Béla Fehér  Sándor Szakáll  Norbert Zajzon  Judith Mihály 《Mineralogy and Petrology》2015,109(4):405-411

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How complex climate networks complement eigen techniques for the statistical analysis of climatological data     

Jonathan F. Donges  Irina Petrova  Alexander Loew  Norbert Marwan  Jürgen Kurths 《Climate Dynamics》2015,45(9-10):2407-2424

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植被时空变化的估算方法   总被引：3，自引：0，他引：3  

李迈和 《地理学报(英文版)》2003,13(4):447-454

Plant diversity is used as an indicator of the well-being of vegetation and ecological systems. Human activities and global change drive vegetation change in composition and competition of species through plant invasions and replacement of existing species on a given scale. However, species diversity indices do not consider the effects of invasions on the diversity value and on the functions of ecosystems. On the other hand, the existing methods for diversity index can not be used directly for cross-scale evaluation of vegetation data. Therefore, we proposed a 3-dimensional model derived from the logistic equation for estimating vegetation change, using native and non-native plant diversity. The two variables, based on the current and the theoretical maximum diversity of native plants on a given scale, and the result of the model are relative values without units, and are therefore scale-independent. Hence, this method developed can be used directly for cross-scale evaluations nf vegetation data, and indirectly for estimatinu ecosvstem or environmental chanue.  相似文献