Despite their technological importance for water splitting, the reaction mechanisms of most water oxidation catalysts (WOCs) are poorly understood. This paper combines theoretical and experimental methods to reveal mechanistic insights...
The winter distribution of many migratory birds wintering in tropical Africa is poorly known. After the crossing of the Sahara Desert, some long-distance migrants typically stay in the Sahel zone for an extended period before continuing migration to their main wintering areas south of the equator. Here we show how two thrush nightingales (
Luscinia luscinia
) fitted with light-level geolocators, after a six to seven week long stay in the Sahel zone of Sudan, moved to an intermediate area in northern Kenya for a month-long stay before continuing to their final wintering areas in southern Africa. These data indicate that thrush nightingales may use three consecutive wintering sites during their stay in Africa. The migratory movements in Africa between wintering sites are well-coordinated with high precipitation in these areas, suggesting that thrush nightingales track peaks of insect abundance occurring after rains. This three-stage wintering strategy has, to our knowledge, previously not been described, and shows that long-distance migrants can have complex wintering behaviour.
In the condensed phase, quantum chemical properties such as many-body effects and intermolecular charge fluctuations are critical determinants of the solvation structure and dynamics. Thus, a quantum mechanical (QM) molecular description is required for both solute and solvent to incorporate these properties. However, it is challenging to conduct molecular dynamics (MD) simulations for condensed systems of sufficient scale when adapting QM potentials. To overcome this problem, we recently developed the size-consistent multi-partitioning (SCMP) quantum mechanics/molecular mechanics (QM/MM) method and realized stable and accurate MD simulations, using the QM potential to a benchmark system. In the present study, as the first application of the SCMP method, we have investigated the structures and dynamics of Na, K, and Ca solutions based on nanosecond-scale sampling, a sampling 100-times longer than that of conventional QM-based samplings. Furthermore, we have evaluated two dynamic properties, the diffusion coefficient and difference spectra, with high statistical certainty. Furthermore the calculation of these properties has not previously been possible within the conventional QM/MM framework. Based on our analysis, we have quantitatively evaluated the quantum chemical solvation effects, which show distinct differences between the cations.
Mid-infrared (MIR) sensors based on attenuated total reflection (ATR) spectroscopy provide robust, rapid and sensitive platforms for the detection of low levels of organic molecules and pollutants.
The use of mid-infrared sensors based on conventional spectroscopic equipment for oil spill monitoring and fingerprinting in aqueous systems has to date been mainly confined to laboratory environments. This paper presents a portable-based mid-infrared attenuated total reflectance (MIR-ATR) sensor system that was used to quantify a number of environmentally relevant hydrocarbon contaminants in marine water. The sensor comprises a polymer-coated diamond waveguide in combination with a room-temperature operated pyroelectric detector, and the analytical performance was optimized by evaluating the influence of polymer composition, polymer film thickness, and solution flow rate on the sensor response. Uncertainties regarding the analytical performance and instrument specifications for dissolved oil detection were investigated using real-world seawater matrices. The reliability of the sensor was tested by exposition to known volumes of different oils; crude oil and diesel samples were equilibrated with seawater and then analyzed using the developed MIR-ATR sensor system. For validation, gas chromatographic measurements were performed revealing that the MIR-ATR sensor is a promising on-site monitoring tool for determining the concentration of a range of dissolved oil components in seawater at ppb to ppm levels.
Gas analysis via mid-infrared (MIR) spectroscopic techniques has gained significance due to its inherent molecular selectivity and sensitivity probing pronounced vibrational, rotational, and roto-vibrational modes. In addition, MIR gas sensors are suitable for real-time monitoring in a wide variety of sensing scenarios. Our research team has recently introduced so-called substrate-integrated hollow waveguides (iHWGs) fabricated by precision milling, which have been demonstrated to be useful in online process monitoring, environmental sensing, and exhaled breath analysis especially if low sample volumes (i.e., few hundreds of microliters) are probed with rapid signal transients. A logical next step is to establish ultralightweight, potentially disposable, and low-cost substrate-integrated hollow waveguides, which may be readily customized and tailored to specific applications using 3D printing techniques. 3D printing provides access to an unprecedented variety of thermoplastic materials including biocompatible polylactides, readily etchable styrene copolymers, and magnetic or conductive materials. Thus, the properties of the waveguide may be adapted to suit its designated application, e.g., drone-mounted ultralightweight waveguides for environmental monitoring or biocompatible disposable sensor interfaces in medical/clinical applications.
The Q3 nature of crystallisation processes is of major interest, as they are among the most frequently occurring reactions associated with a variety of relevant processes in chemistry, biochemistry, and geochemistry. Please check this proof carefully. Our staff will not read it in detail after you have returned it. Translation errors between word-processor files and typesetting systems can occur so the whole proof needs to be read. Please pay particular attention to: tabulated material; equations; numerical data; figures and graphics; and references. If you have not already indicated the corresponding author(s) please mark their name(s) with an asterisk. Please e-mail a list of corrections or the PDF with electronic notes attacheddo not change the text within the PDF file or send a revised manuscript. Corrections at this stage should be minor and not involve extensive changes. All corrections must be sent at the same time. Please bear in mind that minor layout improvements, e.g. in line breaking, table widths and graphic placement, are routinely applied to the final version. Please note that, in the typefaces we use, an italic vee looks like this: n, and a Greek nu looks like this: ν. We will publish articles on the web as soon as possible after receiving your corrections; no late corrections will be made.
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