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101.
Insight into Local Structure and Molecular Dynamics in Organic Solid‐State Ionic Conductors
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Dr. Haijin Zhu Dr. Fangfang Chen Liyu Jin Dr. Luke A. O'Dell Prof. Dr. Maria Forsyth 《Chemphyschem》2014,15(17):3720-3724
Elucidating the rate and geometry of molecular dynamics is particularly important for unravelling ion‐conduction mechanisms in electrochemical materials. The local molecular motions in the plastic crystal 1‐ethyl‐1‐methylpyrrolidinium tetrafluoroborate ([C2mpyr][BF4]) are studied by a combination of quantum chemical calculations and advanced solid‐state nuclear magnetic resonance spectroscopy. For the first time, a restricted puckering motion with a small fluctuation angle of 25° in the pyrrolidinium ring has been observed, even in the low‐temperature phase (?45 °C). This local molecular motion is deemed to be particularly important for the material to maintain its plasticity, and hence, its ion mobility at low temperatures. 相似文献
102.
G. Duchêne C. M. Petrache C. W. Beausang F. A. Beck T. Byrski D. Curien P. J. Dagnall S. Flibotte P. D. Forsyth G. de France B. Haas B. Kharraja J. C. Merdinger D. Prévost C. Schück C. Theisen P. J. Twin J. P. Vivien 《Zeitschrift für Physik A Hadrons and Nuclei》1994,350(1):39-44
Excited states in the nucleus150Tb have been investigated up to spin 39? and 13 MeV excitation energy using the130Te(27Al, 7n) reaction and the EUROGAM array. The theoretical interpretation of the observed states has been performed in the framework of the deformed independent particle model. The analysis of the decay out of the yrast superdeformed band indicates that normal-deformed states with spins between 24? and 28? are fed. 相似文献
103.
Rare earth element substituted bismuth ferrites (BiFeO3) are of enormous importance as magnetoelectric materials. The polycrystalline samples of Bi
x
La1−x
FeO3 (x=0, 0.2, 0.4, 0.6, 0.8) were prepared by solid-state reaction using standard ceramic method. The single-phase formation of
these compounds was confirmed by X-ray diffraction (XRD) studies. The samples with x=0, 0.2, 0.4, 0.6 are found to be orthorhombic while the sample with x=0.8 is triclinic. The dielectric constant (ε′) and dissipation factor (tan δ) were measured in the frequency range 100 Hz
to 1 MHz at room temperature and as a function of temperature at certain fixed frequencies (1 kHz, 10 kHz, 100 kHz, 1 MHz).
All the samples showed dielectric dispersion. The dielectric constant with temperature shows a broad peak; the peak temperature
shifts with frequency which reflects the relaxor-type behavior. The peak above 600 K in the measured temperature range corresponds
to antiferromagnetic ordering temperature (Néel temperature). The broadness of the peak changes with composition. The ac conductivity
as well as ε′ are found to be maximum for the sample x=0.2 at room temperature. 相似文献
104.
CoFe2O4-BaTiO3 composites were prepared using conventional ceramic double sintering process with various compositions. Presence of two phases
in the composites was confirmed using X-ray diffraction. The dc resistivity and thermoemf as a function of temperature in
the temperature range 300 K to 600 K were measured. Variation of dielectric constant (ɛ′) with frequency in the range 100 Hz to 1 MHz and also with temperature at a fixed frequency of 1 kHz was studied. The ac
conductivity was derived from dielectric constant (ɛ′) and loss tangent (tan δ). The nature of conduction is discussed on the basis of small polaron hopping model. The static value of magnetoelectric
conversion factor has been studied as a function of magnetic field. 相似文献
105.
106.
B Yaakobi P Bourke Y Conturie J Delettrez J.M Forsyth R.D Frankel L.M Goldman R.L McCrory W Seka J.M Soures A.J Burek R.E Deslattes 《Optics Communications》1981,38(3):196-200
High conversion efficiency of laser energy into X-rays from a laser irradiated target is of great interest for a variety of dynamical (pulsed) studies, e.g.: radiography of laser-imploded targets, structure determination by diffraction and absorption fine-structure, and X-ray laser pumping. We report here on a frequency tripled Nd : glass laser used to irradiate targets of various materials at ~5 x 1014W/cm2. We find conversion efficiencies of between 1% and 0.1% (with respect to the incident laser energy) for individual X-ray lines between 1.8 and 7.8 keV. These efficiencies are more than an order of magnitude higher than whose achieved with 1.06 μm lasers. 相似文献
107.
Clare BR Bayley PM Best AS Forsyth M MacFarlane DR 《Chemical communications (Cambridge, England)》2008,(23):2689-2691
Commonly used for purification, alumina and silica are found to contaminate ionic liquids with particles; these particles cannot be removed easily and can have a non-negligible impact on the electrochemical, spectroscopic and physical properties of an ionic liquid, including its nucleation and crystallisation kinetics. 相似文献
108.
Bruce MI Cole ML Fung RS Forsyth CM Hilder M Junk PC Konstas K 《Dalton transactions (Cambridge, England : 2003)》2008,(31):4118-4128
The ambient temperature reaction of the N-heterocyclic carbenes (NHCs) 1,3-dimesitylimidazol-2-ylidene (IMes) and 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene (IDipp) with the triruthenium cluster [Ru(3)(CO)(12)], in a 3 : 1 stoichiometric ratio, results in homolytic cleavage of the cluster to quantitatively afford the complexes [Ru(CO)(4)(NHC)] (; NHC = IMes, ; NHC = IDipp). Reaction of the 2-thione or hydrochloride precursors to IMes, i.e. S[double bond, length as m-dash]IMes and IMes.HCl, with the same triruthenium cluster affords the complexes [Ru(4)(mu(4)-S)(2)(CO)(9)(IMes)(2)] () and [Ru(4)(mu(4)-S)(CO)(10)(IMes)(2)] () (3 : 1 and 2 : 1 reaction), and [{Ru(mu-Cl)(CO)(2)(IMes)}(2)] () (3 : 1 reaction) respectively. By contrast, the complex [Ru(3)(mu(3)-S)(2)(CO)(7)(IMeMe)(2)] (), where IMeMe is 1,3,4,5-tetramethylimidazol-2-ylidene, is the sole product of the 2 : 1 stoichiometric reaction of S[double bond, length as m-dash]IMeMe with [Ru(3)(CO)(12)]. Compounds -, and have been structurally characterised by single crystal X-ray diffraction. 相似文献
109.
Bhosale SV Bissett MA Forsyth C Langford SJ Neville SM Shapter JG Weeks L Woodward CP 《Organic letters》2008,10(14):2943-2946
A crystallography-instructed strategy to highly ordered layering of porphyrins with different topologies on HOPG is developed based on meso-tetraarylporphyrins bearing 2-ethoxyethanol side chains as "sticky ends". These sticky ends are capable of displaying directive hydrogen bonding motifs with the inherent D4h symmetry of the porphyrins. Solvent effects are shown to have an important role in fabricating the adsorption. Metalation and subsequent axial ligation was a key controlling factor in the topology of the layer, leading to pseudo-2D structures on HOPG. 相似文献
110.
A multiresidue method was developed to measure low levels of 8 fluoroquinolones (norfloxacin, ofloxacin, danofloxacin, ciprofloxacin, desethylene ciprofloxacin, enrofloxacin, sarafloxacin, and difloxacin) and 4 quinolones (oxolinic acid, flumequine, nalidixic acid, and piromidic acid). Method detection limits range from 0.1 ng/g for quinolones to 0.4 ng/g for fluoroquinolones. Average recoveries range from 57 to 96%, depending on analyte and commodity; relative standard deviations are all less than 18%. The drugs are extracted from tissues using a mixture of ethanol and 1% acetic acid, diluted in aqueous HCI, and defatted by extraction with hexane. The compounds are further isolated using cation-exchange solid-phase extraction and measured using liquid chromatography with electrospray tandem mass spectrometry detection. The method has been evaluated and applied to the analysis of salmon, trout, and shrimp. Detectable residues were observed in 10 out of 73 samples, at concentrations ranging from 0.28 to 16 ng/g. 相似文献