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101.
Johan Lindström Lars Eklundh Jan Holst Ulla Holst 《International journal of remote sensing》2013,34(10):1973-1991
The strong systematic change in solar zenith angles (SZA) due to annual orbital drift of the NOAA satellites has raised the suspicion of the influence of residual illumination on the calibrated normalized difference vegetation index (NDVI) derived from the Pathfinder AVHRR Land (PAL) database. The aim of this work is to analyse if trends in AVHRR NDVI from 1982 to 2000 over the Sahel region in Africa depend on variations in SZA. The analysis uses both ordinary least squares regression and cointegration to analyse possible linear dependencies between NDVI and SZA on a per satellite basis. Tests for integration and cointegration fail to find any significant evidence for either. This, together with the ability of simple deterministic models to explain primarily SZA constitutes evidence against integration and cointegration, indicating that linear relationships can be examined using ordinary linear regression. Regression gives no consistent relationship between NDVI and SZA and the explanatory power (R 2) of the regression is low (on average 0.08). However there is some evidence for downward bias in NDVI due to nonlinear interactions between NDVI and SZA when SZA is large (80°) leading to the conclusion that PAL data from the year 2000 should not be used for analyses in these environments. 相似文献
102.
Natural zeolites, known for their excellent sorption properties towards metal cations, are widely used for the purification of wastewaters. The selectivity of clinoptilolite, a common zeolite mineral, for Pb is known to be particularly high, whereas its selectivity for Cd is often lower. Extraordinarily high sorption capacities for soft metal cations were observed in the case of thiol-functionalized silica gels and clays. In order to enhance the zeolites' sorption capacity for Cd, we treated natural heteroionic and Na-clinoptilolite in aqueous suspensions with cysteamine and propylamine solutions and investigated the sorption of Cd and Pb to amine-modified zeolite by a series of batch experiments. Stability constants for amine sorption on all zeolite samples at room temperature and 50 degrees C were obtained. Partial dimerization of cysteamine explains the enhanced sorption of this compound. In contrast, amine treatment did not enhance the adsorption capacity or selectivity of the clinoptilolite towards Cd and Pb. Instead, the amounts of adsorbed heavy metals decreased stoichometrically with increasing sorption of cysteamine and propylamine. This reduction can be explained by the blockage of channels by amine molecules and revealed that the modification of zeolites with mercaptoamines does not enhance the sorption capacity of zeolite for Cd and Pb. 相似文献
103.
104.
Simultaneous use of time-resolved fluorescence and anti-stokes photoluminescence in a bioaffinity assay 总被引:1,自引:0,他引:1
A bioaffinity assay is described where anti-Stokes photoluminescence of inorganic lanthanide phosphors and time-resolved fluorescence of lanthanide chelates are measured from a single microtitration well without any disturbance from these label technologies to each other. Up-converting phosphor (UPC-phosphor) bioconjugate was produced by grinding the commercial, micrometer-sized UPC-phosphors to colloidal, submicrometer-sized phosphor particles and by attaching these phosphors to biomolecules. Experiments were carried out in standard 96-well microtitration plates to determine detection limits, linearity, and cross-talk of UPC-phosphor and europium chelate. In numbers of molecules the lower limits of detection for UPC-phosphor were roughly 3 x 10(3) particles in solution and 1 x 10(4) particles in solid phase, and for europium label same values were 9 x 10(6) and 9 x 10(7) molecules. Linearity of detection was for UPC-phosphor 5 orders of magnitude in solution and over 4 orders of magnitude in solid phase and for europium label over 5 orders of magnitude in solution and over 4 orders of magnitude in solid phase. The cross-talk between the two labels was practically nonexistent. In this study we show that up-converting anti-Stokes photoluminescent phosphors could be employed in bioaffinity assays as very potential labels with significant advantages either alone or together with long-lifetime lanthanide chelates. 相似文献
105.
106.
Niels Hadrup Vadim Zhernovkov Nicklas Raun Jacobsen Carola Voss Maximilian Strunz Meshal Ansari Herbert B. Schiller Sabina Halappanavar Sarah S. Poulsen Boris Kholodenko Tobias Stoeger Anne Thoustrup Saber Ulla Vogel 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(21)
Inhaled nanoparticles constitute a potential health hazard due to their size‐dependent lung deposition and large surface to mass ratio. Exposure to high levels contributes to the risk of developing respiratory and cardiovascular diseases, as well as of lung cancer. Particle‐induced acute phase response may be an important mechanism of action of particle‐induced cardiovascular disease. Here, the authors review new important scientific evidence showing causal relationships between inhalation of particle and nanomaterials, induction of acute phase response, and risk of cardiovascular disease. Particle‐induced acute phase response provides a means for risk assessment of particle‐induced cardiovascular disease and underscores cardiovascular disease as an occupational disease. 相似文献
107.
Summary The amount of secondary oxidation products in refined and unrefined fats has been determined by reaction with benzidine acetate
in iso-octane absolute alcohol solution, and measurement of the absorption at 350 mμ of the yellow color has been made.
An “aldehyde value” has been calculated from this absorption intensity, using cinnamaldehyde as a reference substance. Determination
of the aldehyde value and peroxide number of oils before and during refining has given information on the effect of the different
refining processes on the state of oxidation of the oils. The effect of hardening on the content of oxidation products of
an oil has been investigated. The effect of the amount of oxidation products in the unrefined material on the flavor stability
of the refined material and of the margarine made from it has also been studied. 相似文献
108.
109.
Erika Winquist Lara Valentin Ulla Moilanen Matti Leisola Annele Hatakka Marja Tuomela Kari T. Steffen 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2009,84(6):845-850
BACKGROUND: Combustion at high temperature is a common treatment method for heavily contaminated soils. The capacity of the combustion process is negatively correlated with organic matter content of the soil. Thus, by reducing the amount of soil organic matter, batch size could be increased and the combustion process improved. In this study, the possibility to pre‐treat soil containing high levels of organic matter with white‐rot and litter‐decomposing fungi was examined and scaled up. RESULTS: Calculations based on the CO2 production in laboratory experiments indicated that 20% of the soil organic carbon would have been degraded in 6 months when treated with Sphaerobolus stellatus and 10% when treated with Stropharia rugosoannulata. In a pilot‐scale experiment with S. rugosoannulata mass loss due to degradation of soil organic matter accounted for 10% of the total weight of the soil in 6 months. CONCLUSION: A fungal pre‐treatment process for contaminated soils with high organic matter content was developed. Good results were obtained with S. stellatus and S. rugosoannulata and the process was successfully scaled up to 300 kg scale. Copyright © 2009 Society of Chemical Industry 相似文献
110.
T?nnesvang Jan; Sommer Ulla; Hammink James; Sonne Mikael 《Canadian Metallurgical Quarterly》2010,47(4):586
The article investigates the relationship between crucial concepts and understandings in gestalt therapy and cognitive therapy aiming at discussing if and how they can be mutually enriching when considered as complementary parts in a more encompassing integrative therapeutic approach. It is argued that gestalt therapy, defined as a field-theoretical approach to the study of gestalt formation process, can complement the schema-based understanding and practice in cognitive therapy. The clinical benefits from a complementary view of the two approaches will be a wider scope of awareness toward individual and contextual aspects of therapeutic change processes, toward different levels of memory involved in these processes, and toward the relationship between basic needs, sensation and cognition in therapeutic work. Further, a dialogue between the two approaches will pave the way for addressing the connection between fundamental awareness work in gestalt therapy and the tendency within cognitive therapy toward incorporating mindfulness as a therapeutic tool. In the conclusion of the article, additional complementary points between the two approaches are outlined. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献