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[en] The measuring accuracy of magnetic probes is greatly improved by eliminating the disturbance of TF coils through a new discharge scenario, together with a careful calibration process. The measuring accuracy of flux loop is also improved by removing the clamping diodes in integrator which cause the loss of fast information. With accurate magnetic field and flux information input, the iteration and fitting process of EFIT converges quickly and outputs reliable results, which are consistent with diagnostic results achieved by Langmuir probes, Hα array and CCD image. A new self-developed plasma equilibrium reconstruction code, called sFIT, is also introduced, which outputs the plasma shape information that agrees very well with that of EFIT. (authors)
[en] This paper focuses on the preparation of boron doped ZnO (ZnO:B) films prepared by nonreactive mid-frequency magnetron sputtering from ceramic target with 2 wt.% doping source. Adjusting power density, ZnO:B film with low resistivity (1.54 × 10−3 Ω cm) and high transparency (average transparency from 400 to 1100 nm over 85%) was obtained. Different deposition conditions were introduced as substrate fixed in the target center and hydrogen mediation. Hall mobility increased from 11 to above 26 cm2/V·s, while carrier concentration maintained almost the same, leading to low resistivity of 6.45 × 10−4 Ω cm. Transmission spectra of ZnO:B films grown at various growth conditions were determined using a UV–visible-NIR spectrophotometer. An obvious blue-shift of absorption edge was obtained while transmittances between 600 nm and 1100 nm remained almost the same. Optical band baps extracted from transmission spectra showed irregular enhancement due to the Burstein–Moss effect and band gap renormalization. Photoluminescence spectra also showed a gradual increase at UV emission peak due to free exciton transition near band gap. We contributed this enhancement in both optical band gap and UV photoluminescence emission to the lattice structure quality melioration. - Highlights: ► Boron doped ZnO films have been prepared by magnetron sputtering. ► Different deposition conditions are introduced to make properties melioration. ► Hall mobility increases by using static deposition mode and hydrogen mediation. ► Optical band gap increases with static mode and hydrogen mediation. ► Lattice structure quality melioration is assumed to explain this improvement.
[en] Graphical abstract: -- Highlights: •PPY-GO-BiCoPc composite was formed using a simple electrochemical method for the first time. •A novel PoPD-MIP sensor based on PPY-GO-BiCoPc composite had been fabricated. •The PPY-GO-BiCoPc functional composite was introduced to improve performance of the sensor. •Highly sensitive, selective and stable sensor had been achieved. •The established MIP sensor could be promising in food safety analysis. -- Abstract: A facile and efficient molecularly imprinted polymer (MIP) recognition element of electrochemical sensor was fabricated by directly electro-polymerizing monomer o-phenylenediamine (oPD) in the presence of template quinoxaline-2-carboxylic acid (QCA), based on one-step controllable electrochemical modification of poly(pyrrole)-graphene oxide-binuclear phthalocyanine cobalt (II) sulphonate (PPY-GO-BiCoPc) functional composite on glassy carbon electrode (GCE). The MIP film coated on PPY-GO-BiCoPc functional composite decorated GCE (MIP/PPY-GO-BiCoPc/GCE) was presented for the first time. The synergistic effect and electro-catalytic activity toward QCA redox of PPY-GO-BiCoPc functional composite were discussed using various contrast tests. Also, the effect of experimental variables on the current response such as, electro-polymerization cycles, template/monomer ratio, elution condition for template removal, pH of the supporting electrolyte and accumulation time, were investigated in detail. Under the optimized conditions, the proposed MIP sensor possessed a fast rebinding dynamics and an excellent recognition capacity to QCA, while the anodic current response of square wave voltammetry (SWV) was well-proportional to the concentration of QCA in the range of 1.0 × 10−8–1.0 × 10−4 and 1.0 × 10−4–5.0 × 10−4 mol L−1 with a low detection limit of 2.1 nmol L−1. The established sensor was applied successfully to determine QCA in commercial pork and chicken muscle samples with acceptable recoveries (91.6–98.2%) and satisfactory precision (1.9–3.5% of SD), demonstrating a promising feature for applying the MIP sensor to the measurement of QCA in real samples
[en] This article introduced the theory and interpretation principles of BHTEM. A case study was made in deep borehole of CUSD3 for Uranium Science in Xiangshan. With field data analysis we inferred the orientation of the Lead-zinc mineralization center near the borehole, which shew BHTEM had an advantage in detecting good conductors in volcanic area. Combined with CUSD3, BHTEM is considered a useful method which has high detect accuracy, and can find out key uranium mineralization and ore-controlling factors, such as rock interface and faults near the hole, which will be very helpful to further exploration of uranium deposits. (authors)
[en] We have theoretically investigated the population transfer and the selective excitation of vibrational states of the target state in a three-state Na2 molecule using the chirped adiabatic passage. The population transfer among electronic states is studied. Compared with the single negative chirped pulse, complete population transfer can be achieved by using a positive chirped pulse. The effects of laser parameters on vibrational population distribution are discussed, and the selective excitation of vibrational states can be achieved by adjusting the central frequency. Finally, we give the method of selective excitation of specific vibrational states. (paper)
[en] Graphical abstract: The incorporation of La"3"+ ions in KTaO_3 host lattice led to a monotonous lattice contraction and particle size reduction, showing an excellent photocatalytic performance. - Highlights: • La"3"+ incorporation in KTaO_3 led to a lattice contraction, particle size reduction. • Oxidative capacity of the photo-excited carriers increases after La"3"+ ions doping. • Ta"4"+ appearance was helpful for the separation of electron-hole pairs. • Photocatalytic performance of K_1_−_xLa_xTaO_3 optimized by La"3"+ doping. - Abstract: La"3"+-doped cubic potassium tantalate photocatalysts were prepared by a hydrothermal treatment process. It is found that the La"3"+ ions were homogeneously incorporated in the KTaO_3 host lattice, leading to a monotonous lattice contraction and particle size reduction. Meanwhile, the BET surface areas were also enlarged from 4.9 to ∼9.8 m"2 g"−"1. Consistently, La"3"+-doped KTaO_3 nanocrystals showed a broadened band gap, which can be well-defined as a consequence of the contractive particle size. DFT calculation predicted a deeper band edge and a dispersive dense state of valance state by La"3"+ ions doping due to the hybridization of O 2p and La 6p orbitals, increasing the oxidative capacity and mobility of photogenerated charge carriers, thus enhance the photocatalytic activity. The mixed state of Ta"5"+ and Ta"4"+ was found to appear in the K_1_−_xLa_xTaO_3 nanocrystals, which may suppress the formation of cationic vacancies. The superior photocatalytic performance of K_1_−_xLa_xTaO_3 nanocrystals was achieved by well-controlled contractive particle size and optimized La"3"+ doping level
[en] An orthogonal field experiment of giant reed (Arundo donax) modified with organic complex fertiliser (OCF), and OCF and fly ash (O&F), at different planting densities was carried out in metal-contaminated soil. The available percentage of arsenic (As) and lead (Pb) in soil decreased from 8.45% to 2.19% and from 29.6% to 13.5% by OCF, respectively, and that of cadmium (Cd) was reduced from 25.3% to 6.49% by O&F. The total biomass of giant reed was 631 g per individual following application of O&F in contaminated soil. The accumulation of As, Cd, and Pb in giant reed was 1.57, 4.06, and 11.25 mg per individual. Urease and sucrase activity were 87.4 NH4-N μg/g d and 63.1 glucose mg/g d in response to the treatments modified using OCF, while the highest dehydrogenase activity was 101 TPF (triphenyltetrazolium formazan) μg/g d in the treatments modified using O&F. Dominant bacteria (frequency > 50%) were enriched with increasing planting density of giant reed. These results indicate that the phytostabilisation of metal-contaminated soil by giant reed could be improved by the application of O&F or OCF. - Highlights: • Both OCF and O&F increased biomass of giant reed and decreased available content of As, Cd and Pb in soil. • Dominant bacteria communities were enriched with increased planting density of giant reed in contaminated soil. • DHA was a reliable indicator of soil eco-environmental quality in phytoremediation with giant reed.
[en] Objective: To explore the character of the regional cerebral blood flow (rCBF) of heroin addicts during the exposure to the heroin-related cues. Methods: Twenty-five heroin dependent individuals undergoing detoxification for more than one month were enrolled in the present study. All subjects were exposed to the heroin-related cues for 15 min. The rCBF was measured in these patients before and after exposure to heroin-related cues. Result: The rCBF in the frontal, temporal cortex and amygdala was significantly increased during the exposure to heroin-related cues. Conclusion: The findings indicate that drug-related cues play a critical role in the relapse of drug dependence; and the frontal, temporal cortex and amygdala are involved in the relapsing process
[en] We theoretically study the field-free molecular orientation by the combination of a two-color femtosecond laser pulse and a time-delayed terahertz (THz) laser pulse, with LiH as the prototype molecule. It is shown that the molecular hyperpolarizability is a vital parameter in achieving molecular orientation according to the pre-excitation created by an intense two-color femtosecond laser pulse. The relative amplitude of the two-color femtosecond pulse is discussed. In addition, the center frequency of the THz laser pulse is chosen on the basis of the pre-excited population distributions. The carrier-envelope phase of the THz laser pulse as well as the delay time between the femtosecond laser pulse and THz laser pulse are adjusted to achieve a high orientation degree. In addition, the effect of temperature on molecular orientation is also discussed. Finally, according to the population distributions at room temperature, the parameters of the THz laser pulse are re-optimized, and the achieved maximal orientation degree is 0.221 at 300 K. (paper)
[en] A two-stage monolithic microwave integrated circuit (MMIC) low noise amplifier (LNA) fabricated in 0.5 μm GaAs pHEMT is presented. The Miller effect introduced by the parasitic gate–drain capacitance is utilized to decrease the value of the input inductor. Additionally, the input on-chip inductor is a novel high Q gradual structure. The noise figure is reduced with these two methods. With good input and output matching, the LNA achieves a noise figure of 0.75 dB and a small signal gain of 32.7 dB over 698–806 MHz. The input 1 dB compression point is −21.8 dBm and the input third order interception point is −10 dBm. (paper)