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Philippe Quevauviller Gemma Rauret Allan Ure Roser Rubio José-Fírmin López-Sánchez Haidé Fiedler Herbert Muntau 《Mikrochimica acta》1995,120(1-4):289-300
The determination of extractable trace metal contents in soil using single extraction procedures is currently performed in many laboratories to assess the bioavailable metal fraction (and related phytotoxic effects) and the accessability to the environment (e.g. contamination of ground waters). Owing to the need for validation of the extraction schemes used and of the analytical techniques, the EC Measurements and Testing Programme (formerly BCR) has organized a project for improving the quality of determination of extractable trace metal contents in soil, the first step being an interlaboratory study to adopt common extraction procedures and the second being a certification campaign to certify two soils for their extractable trace element contents following these procedures. This paper gives a brief overview of the project organisation and describes the preparation, homogeneity and stability studies of two soil candidate reference materials (sewage sludge-amended and terra rossa soils). 相似文献
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Song Xue Richard W. Haid Regina M. Kluge Xing Ding Batyr Garlyyev Johannes Fichtner Sebastian Watzele Shujin Hou Aliaksandr S. Bandarenka 《Angewandte Chemie (International ed. in English)》2020,59(27):10934-10938
Herein, we demonstrate an easy way to improve the hydrogen evolution reaction (HER) activity of Pt electrodes in alkaline media by introducing Ni–Fe clusters. As a result, the overpotential needed to achieve a current density of 10 mA cm?2 in H2‐saturated 0.1 m KOH is reduced for the model single‐crystal electrodes down to about 70 mV. To our knowledge, these modified electrodes outperform any other reported electrocatalysts tested under similar conditions. Moreover, the influence of 1) Ni to Fe ratio, 2) cluster coverage, and 3) the nature of the alkali‐metal cations present in the electrolyte on the HER activity has been investigated. The observed catalytic performance likely originates from both the improved water dissociation at the Ni–Fe clusters and the subsequent optimal hydrogen adsorption and recombination at Pt atoms present at the Ni–Fe/Pt boundary. 相似文献
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Richard W. Haid Xing Ding Theophilus Kobina Sarpey Aliaksandr S. Bandarenka Batyr Garlyyev 《Current Opinion in Electrochemistry》2022
Understanding the electrical double-layer structure is of paramount importance for designing efficient electrochemical energy conversion systems. Under this aspect, this short review explores the influence of the electrolyte on parameters such as the double-layer capacitance and the potential of maximum entropy. Investigation of those parameters offers a deeper understanding on how the interfacial structure changes near reaction conditions. As a consequence, one can tune the catalyst activity by creating a more favorable environment in the electrolyte. The aim of this short review is to provide the reader with recent studies examining the electrode/electrolyte interface from experimental and theoretical standpoints. 相似文献
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Tapia R Guardia JJ Alvarez E Haidöur A Ramos JM Alvarez-Manzaneda R Chahboun R Alvarez-Manzaneda E 《The Journal of organic chemistry》2012,77(1):573-584
A new strategy for synthesizing taiwaniaquinoids, a group of terpenoids with an unusual rearranged 5(6→7) or 6-nor-5(6→7)abeo-abietane skeleton, which exhibit promising biological activities, is reported. The procedure, based on the cleavage of the C7-C8 double bond of abietane diterpenes, is the only one yet reported for synthesizing C(20) taiwaniaquinoids bearing a carbon function on the cyclopentane B ring; it is also applicable to the synthesis of the wide variety of existing taiwaniaquinoids. Utilizing this, (-)-taiwaniaquinone A, F, G, and H, (-)-taiwaniaquinol B, and (-)-dichroanone have been synthesized from (+)-abietic acid. The versatility of this strategy allows us to propose the abietane C7-C8 cleavage as a possible biosynthetic pathway to this type of rearranged diterpenes; this proposal seems to be supported by phytochemical evidence. 相似文献
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Houari M. Bouadjemi B. Abbad A. Lantri T. Haid S. Benstaali W. Matougui M. Bentata S. 《JETP Letters》2020,112(6):364-369
JETP Letters - Structural, electronic and optical properties for halide double perovskites compounds K2GeSnBr6 and K2GeSnI6 are studied in this work. Based on the (FP-LAPW) method, the previous... 相似文献
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O. Buresch W. Hönle U. Haid und H. G. v. Schnering 《Fresenius' Journal of Analytical Chemistry》1987,328(1-2):82-84
Summary Decompositions of inorganic and organic materials can be carried out within a few minutes by means of the microwave technique. For dissolving substances with volatile components in the microwave oven, low pressure containers were developed from microwave transparent materials and an excess pressure security system. Results and limitations of the method are explained by examples. 相似文献
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Dr. Chantal D. Bader Dr. Fabian Panter Dr. Ronald Garcia Dr. Egor P. Tchesnokov Dr. Sibylle Haid Christine Walt Dr. Cathrin Spröer Dr. Alexander F. Kiefer Prof. Dr. Matthias Götte Prof. Dr. Jörg Overmann Prof. Dr. Thomas Pietschmann Prof. Dr. Rolf Müller 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(10):e202104484
10.
A. Picard H. Backe J. Bonn B. Degen R. Haid A. Hermanni P. Leiderer A. Osipowicz E. W. Otten M. Przyrembel M. Schrader M. Steininger Ch. Weinheimer 《Zeitschrift für Physik A Hadrons and Nuclei》1992,342(1):71-78
This paper reports on precision measurements of conversion lines in the decay of83mKr with nuclear transition energies of 32.1 keV and 9.4 keV, respectively. The spectra were taken from a submonolayer surface of83m Kr frozen onto a cold backing, using the new Mainz solenoid retarding spectrometer. The high luminosity and resolution of this instrument enables the observation of all allowed conversion lines up to theN-shell and to fully separate the elastic component from inelastic satellites. The combined analysis of the data yields the transition energiesE y=32151.5±1.1 eV and 9405.9±0.8 eV, respectively. The experiment served also to pilot the application of this spectrometer to the question of a finite neutrino rest mass, searched for in theβ-decay spectrum of tritium and to problems in precision electron spectroscopy in general. 相似文献