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An electron heating mechanism based on a resonance between the cyclotron motion of electrons and the radio frequency sheath oscillations is reported in weakly magnetized capacitively coupled plasmas at low pressure. If half of the electron cyclotron period coincides with the radio frequency period, then electrons will coherently collide with the expanding sheath and gain substantial energy, which enhances the plasma density. A relation between the magnetic field and the driving frequency is found to characterize this resonance effect and the kinetics of electrons are revealed at resonance conditions for various driving frequencies.

New colorimetric and fluorometric fluoride ion probe, anthra[1,9-cd]pyrazol- 6(2H)-one (1), was synthesized by one-step condensation. The probe 1 shows F−-selective color change from colorless to pink and appearance of red fluorescence. The fluorescence quantum yield of free probe 1 in DMSO was calculated to be 0.03. After addition of 15 equiv. of F−, its fluorescence quantum yield can be increased to 0.37. The analytical detection limit for F− was 2.8 × 10− 7 M. 1H NMR analysis and DFT calculation show that the F−-induced colorimetric and fluorometric responses of 1 are driven by deprotonation process.

A high-performance bandgap reference voltage source design method is proposed in this paper, according to the shortcomings of traditional bandgap reference voltage source. This method combined CSMC 0.35μm CMOS process with Aether software technology, enabling to improve the bandgap reference source op amp performance and take into account accuracy and stability of the system. From the experimental results: this bandgap reference voltage source output voltage has changed about 63 mV when the temperature varied from to , and the line regulator is 0.4mV/V when the power supply voltage varied from 3.2V to 3.3V. This system has advantages of high accuracy and good stability.

(Pt–NbPO x )/multi-walled carbon nanotubes (MWCNTs) with different NbPO x MWCNTs were prepared by a simple microwave irradiation method. The (Pt–NbPO x )/MWCNTs catalyst was characterized, and the kinetics toward oxygen reduction reaction (ORR) was determined, compared with that of Pt/MWCNTs catalyst. It was found that 10 wt% NbPO x was the best loading in terms of current density. The number of exchange electrons for the ORR was found to be close to four on both (Pt–NbPO x )/MWCNTs and Pt/MWCNTs.

Sn(IV) doped and nano-sized TiO 2 immobilized on active carbon (AC) (Sn(IV)/TiO 2 /AC) were prepared by the sol–gel and dip-calcination method. An azo dye, Orange G (OG), was used as a model compound to study its photocatalytic activity in a fluidized bed photoreactor. The addition of Sn(IV) on TiO 2 could greatly improve the activity of TiO 2 , and the optimal amount of tin was 2.5 at.%. The effects of calcination temperature, pH value, the initial hydrogen peroxide concentration ([H 2 O 2 ] 0 ), the catalyst amount ([TiO 2 ]), the initial OG concentration ([dye] 0 ) and co-existing negative ions on the photocatalytic activity of Sn(IV)/TiO 2 /AC were studied. The optimal conditions were as follows: pH 2.00, [H 2 O 2 ] 0 = 1.5mL/L, [dye] 0 = 50 mg/L, [TiO 2 ] = 12.5 g/L, when the 300 W high pressure mercury light was used as the light source. Under these conditions, the degradation efficiency of OG reached 99.1% after 60 min reaction. The kinetics of the OG degradation was also analyzed. The results showed that the kinetics of this reaction fit the Langmiur–Hinshelwood kinetics model well and the absorption of OG on the Sn(IV)/TiO 2 /AC surface was the controlling step in the whole degradation process. In addition, the catalyst, liquid and gas were separated effectively, and the integrative process of reaction and separation was achieved during the experiment.

In inductively coupled plasma sources, discharge transitions from electrostatic mode (E mode) to electromagnetic mode (H mode) and from H mode to E mode occur. In previous studies, only a few works paid attention to the effects of the impedance matching network. Cunge et al. [Plasma Sources Sci. Technol. 8, 576 (1999)] investigated the E-H and H-E mode transitions under two different impedance matching situations, but no physical mechanism or interpretation was presented. This issue is remained to be systematically and quantitatively investigated, and the underlying mechanism to be unveiled. In this paper, the effects of the impedance matching network were experimentally studied in electropositive argon gas by varying the series capacitance in an inversely L-shaped matching network. The positive and negative feedback regions are established according to the effect of varying the series capacitance on the output power of the rf power supply. It was found that under the same experimental parameters, the dis...