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2.
By employing the perturbation formulae of the spin Hamiltonian parameters (SHPs) (g factors gxx, gyy, gzz, hyperfine structure constants Axx, Ayy, Azz and superhyperfine parameters Axx׳, Ayy׳, Azz׳) for a 3d1 ion in orthorhombically elongated octahedra and tetrahedra, the defect structures and the experimental EPR spectra are theoretically and systematically investigated for the two orthorhombic Ti3+ centers C1 and C2 in ZnWO4. Center C1 is ascribed to the impurity Ti3+ at host W6+ site associated with two nearest neighbor oxygen vacancies due to charge compensation. The resultant tetrahedral [TiO4]5– cluster is determined to undergo the local orthorhombic elongation distortion, characterized by the axial distortion angle Δθ (=θ–θ0≈–6.84°) of the local impurity-ligand bond angle θ related to θ0 (≈54.74°) and the perpendicular distortion angle Δε (=ε–ε0≈2.5°) related to ε0 (≈45°) of an ideal tetrahedron because of the Jahn–Teller effect. Center C2 is attributed to Ti3+ on Zn2+ site, and this octahedral [TiO6]9– cluster may experience the local axial elongation ΔZ (≈0.001 Ǻ) and the planar bond angle variation Δφ (≈9.1°) due to the Jahn–Teller effect, resulting in a more regular oxygen octahedron. All the calculated SHPs (i.e., g factors for both centers, the hyperfine structure constants for center C2 and superhyperfine parameters of next nearest neighbor ligand W for center C1) show good agreement with the observed values. However, the theoretical results based on the previous assignment of center C1 as Ti3+ on W6+ site with only one nearest planar oxygen vacancy (i.e., five-fold coordinated octahedral [TiO5]7– cluster) show much worse agreement with the experimental data. The defect structures and the SHPs (especially the g anisotropies) are discussed for both centers. The present studies on the superhyperfine parameters of ligand W6+ for center C1 would be helpful to further investigations on the superhyperfine interactions of cation ligands which were rather scarcely treated before. 相似文献
3.
Salting‐out‐assisted liquid–liquid extraction with acetonitrile for the determination of trimetazidine in rat plasma using liquid chromatography–mass spectrometry 下载免费PDF全文
A high‐throughout bioanalytical method based on salting‐out‐assisted liquid/liquid extraction (SALLE) method with acetonitrile and mass spectrometry‐compatible salts followed by LC‐MS/MS analysis of trimetazidine in rat plasma is presented. It required only 50 μL of plasma and allows the use of minimal volumes of organic solvents. The seamless interface of SALLE and LC‐MS eliminated the drying‐down step and the extract was diluted and injected into an LC‐MS/MS system with a cycle time of 2.5 min/sample. The retention times of trimetazidine and IS were approximately 1.1 and 1.7 min, respectively. Calibration curves were linear over the concentration range of 0.1–100 ng/mL, which can be extended to 500 ng/mL by dilution. The intra‐ and inter‐batch precision, accuracy and the relative standard deviation were all <15%. This method was successfully applied to determine trimetazidine concentrations in rat plasma. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
4.
Degradation of pyrene in soil in a net-to-net pulsed discharge plasma (PDP) system was reviewed. Effect of main chemical parameters, including air flow rate, pyrene concentration, initial pH and soil moisture content on pyrene degradation was examined. The obtained results show that 87.9% of pyrene could be removed under the condition of 60 min reaction; increasing of air flow rate within 1 L min−1 was favorable for degradation; pyrene removal was decreased with the increase of initial pyrene concentration; oxidation of pyrene was more evident in acidic soil; enhancement of soil moisture content has no benefit on pyrene degradation. 相似文献
5.
Plasma-assisted flow control is of high industrial interest, but practical applications at full scale require a large surface of interaction. Nanosecond pulsed Dielectric Barrier Discharge (DBD) have demonstrated promising results of flow control, but their interacting region is limited to only a few cm2. In this paper, the conditions to extend a surface nanosecond DBD are documented. It is shown that a sliding discharge regime can fully fill an inter-electrode distance of 40 mm. This discharge regime promotes the formation of two hemispheric pressure waves originating from both air-exposed electrodes while an horizontal region of pressure gradient is also observed. 相似文献
6.
HPLC with fluorescence detection assay of perampanel,a novel AMPA receptor antagonist,in human plasma for clinical pharmacokinetic studies 下载免费PDF全文
Perampanel (Fycompa®), a novel α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionic acid (AMPA) receptor antagonist, is registered for the adjunctive treatment of patients (aged ≥12 years) with refractory partial‐onset seizures. To support therapeutic drug monitoring, a simple high‐performance liquid chromatography (HPLC) assay with fluorescence detection was developed to determine perampanel concentrations in human plasma and validated to support clinical trials. Human plasma samples (1.0 mL) were processed by liquid extraction using diethyl ether, followed by chromatographic separation on a YMC Pack Pro C18 column (150 × 4.6 mm i.d., 5 µm) with isocratic elution of acetonitrile–water–acetic acid–sodium acetate (840:560:3:1.8, v/v/v/w) at a flow rate of 1.0 mL/min. Column eluent was monitored at excitation and emission wavelengths of 290 and 430 nm, respectively. The assay was linear (range 1.0–500 ng/mL) and this could be extended to 25 µg/mL by 50‐fold dilution integrity. No endogenous peaks were detected in the elution of analytes in drug‐free blank human plasma from six individuals and no interference was observed with co‐medications tested. Intra‐ and inter‐batch reproducibility studies demonstrated accuracy and precision within the acceptance criteria of bioanalytical guidelines. Validation data demonstrated that our assay is simple, selective, reproducible and suitable for therapeutic drug monitoring of perampanel. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
7.
M. V. Kartikeyan G. Singh E. Borie B. Piosczyk M. Thumm 《International Journal of Infrared and Millimeter Waves》2006,27(5):657-670
The feasibility of an 84 GHz, 500 kW, CW gyrotron for ECRH on an experimental tokamak will be presented in this paper. Mode
competition and mode selection procedures are carefully investigated by considering various candidate modes and the TE10,4 mode is chosen as the operating mode. A conventional cylindrical cavity resonator with weak input and output tapers and parabolic
roundings is considered for interaction studies. Self-consistent, both single mode and time-dependent, calculations are carried
out and power and efficiencies are computed for a typical set of beam parameters. The results show that an output power of
well over 500 kW, CW and efficiency around 40% can be reached without a depressed collector. 相似文献
8.
The excitation of eigen surface waves by tubular electron beams in cylindrical discharge devices is studied. The influence of the wave‐field azimuthal structure on the excitation efficiency and nonlinear stage of the plasmabeam instability is investigated both numerically and analytically. Analytical expressions for the saturation amplitude and excitation efficiency of the wave under study are derived. They are found to agree well with results obtained by numerical modelling of the plasma‐beam interaction presented in this paper. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
9.
A Garcia-Quiroz David L AzevedoE.C da Silva 《Journal of Physics and Chemistry of Solids》2002,63(10):1863-1866
Properties of oxygenated carbon nitride films have attracted the attention of physics researchers due to their magnetic and physical properties, as well as for their usefulness in the industry. The free radicals were investigated using electron paramagnetic resonance applied in the study of spin concentration due to the different mechanism of preparation of carbon nitride films by RF-discharge with different kinds of plasma. Unpaired spin concentrations, in the order of 1020 per cm3, were measured and their time recombination dependency was important in those films. The films were grown by plasma enhanced chemical vapor deposition using mixtures of hydrocarbons, N2 and O2 in different proportions. 相似文献
10.