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91.
In this study, magnetic resonance imaging (MRI) is used to visualize acoustic streaming in liquids. A single-shot spin echo sequence (HASTE) with a saturation band perpendicular to the acoustic beam permits the acquisition of an instantaneous image of the flow due to the application of ultrasound. An average acoustic streaming velocity can be estimated from the MR images, from which the ultrasonic absorption coefficient and the bulk viscosity of different glycerol-water mixtures can be deduced. In the same way, this MRI method could be used to assess the acoustic field and time-average power of ultrasonic transducers in water (or other liquids with known physical properties), after calibration of a geometrical parameter that is dependent on the experimental setup.  相似文献   
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Due to climatic change, many Alpine glaciers have significantly retreated during the last century. In this study we perform the numerical simulation of the temporal and spatial change of Rhonegletscher, Swiss Alps, from 1874 to 2007, and from 2007 to 2100.  相似文献   
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A spiropyran‐based switchable ligand isomerizes upon reaction with lanthanide(III) precursors to generate complexes with an unusual N3O5 coordination sphere. The air‐stable dysprosium(III) complex shows a hysteresis loop at 2 K and a very strong axial magnetic anisotropy generated by the merocyanine phenolate donor.  相似文献   
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Atom transfer radical polymerization (ATRP) has been utilized to synthesize tri‐ and star‐block copolymers of poly(di(ethylene glycol)methyl ether methacrylate) (PDEGMA) and quaternized poly(2‐(dimethylamino)ethyl methacrylate) (qPDMAEMA). The block copolymers, all with a minimum of two cationically charged blocks, were sequentially used for electrostatic macrocrosslinking of a dilute dispersion of anionic TEMPO‐oxidized cellulose nanofibrils (CNF, 0.3 wt%), forming free‐standing hydrogels. The cationic block copolymers adsorbed irreversibly to the CNF, enabling the formation of ionically crosslinked hydrogels, with a storage modulus of up to 2.9 kPa. The ability of the block copolymers to adsorb to CNF was confirmed by quartz crystal microbalance with dissipation monitoring (QCM‐D) and infrared spectroscopy (FT‐IR), and the thermoresponsive properties of the hydrogels were investigated by rheological stress and frequency sweep, and gravimetric measurements. This method was shown to be promising for the facile production of thermoresponsive hydrogels based on CNF. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 3415–3424  相似文献   
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The synthesis, photophysical properties, and applications in scintillation counting of N‐(2‐ethylhexyl)carbazole (EHCz) are reported. This molecule displays all of the required characteristics for an efficient liquid scintillator (emission wavelength, scintillation yield), and can be used without any extra fluorophores. Thus, its scintillation properties are discussed, as well as its fast neutron/gamma discrimination. For the latter application, the material is compared with the traditional liquid scintillator BC‐501 A, and other liquid fluorescent molecules classically used as scintillation solvents, such as xylene, pseudocumene (PC), linear alkylbenzenes (LAB), diisopropylnaphthalene (DIN), 1‐methylnaphthalene (1‐MeNapht), and 4‐isopropylbiphenyl (iPrBiph). For the first time, an excimeric form of a molecule has been advantageously used in scintillation counting. A moderate discrimination between fast neutrons and gamma rays was observed in bulk EHCz, with an apparent neutron/gamma discrimination potential half of that of BC‐501 A.  相似文献   
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Three analogs of the cytostatic drug ifosfamide incorporating 1‐methyl‐2‐chloroethyl side chains were designed and prepared as an attempt to obtain drugs of lower toxicity.  相似文献   
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