传统仪用变换器与现代光PT光CT

随着电力工业的发展,电力系统超高压大容量化的同时,要求电力设备有更高的可靠性。在系统发生事故时要求高速切除故障区,并对事故原因作出正确判断,仪用变压器变流器在出色完成这一任务中起着重要作用。近年来,变电所开始使用SF_6气体绝缘断路器,它要求精度高、质量可靠、小型化的仪用变压器变流器相配合。随着光纤技术的进步。

普通小麦PTS光温敏雄性不育的遗传分析

以 PTS和常规品种 (系 )小偃 6号、西农 872 7、小偃 2 2、陕 2 2 9、陕 785 9、周麦 1 1等互为父母本进行杂交 ,分期播种 F1 和 F2 ,田间考察自交结实率和育性分离情况。结果表明 :F1 正反交组合的结实率不受细胞质影响 ,说明 PTS系的育性遗传为核基因控制。同时 ,F2 代育性变化是一个连续的过程 ,以结实率 70 %为界划分可育与不育及半不育时 ,出现 3∶ 1的分离比 ,因此认为 PTS系的不育表达是一主效隐性基因和多个微效 (修饰 )

Preparation and Properties of C-axis Oriented PT/PEK-c Films

The preparation of PT/PEK c films is reported as well as their dielectric and optical properties. The c axis orientation ratio of the films is 68%. Dielectric constant and loss factor at 10 kHz is about 4.023 F/m and 0.003, respectively. The refractive indices of the films, n e and n o, are 1.657 3 and 1.627 8 at 0.63 μm wavelength, respectively. The optical band gap of the film with a thickness of 2.33 μm is found to be 3.06 eV.

Effect of the interfacial electric field on the HER on Pt(111)modified with iron adatoms in alkaline media

The study of the hydrogen evolution reaction(HER)aimed to reach a deeper understanding of the parameters that control the rate of this reaction is of great importance given the technical relevance of hydrogen production as an energy vector in the so-called hydrogen economy.In previous works,laser-induced temperature jump(LITJ)experiments on Pt(111)modified with Ni(OH)_(2)in alkaline media have revealed the importance of the interfacial electric field in the rate of the HER.It was hypothesised that small amounts of Ni(OH)_(2)cause a decrease of the electric field because of a negative shift of the pzfc toward the onset of the hydrogen evolution.In this work,to test the validity of this hypothesis,the study has been extended to Pt(111)surfaces modified with Fe(OH)_(2).The modified surfaces have been studied voltammetrically,and the voltammetric charges have been analysed.The voltammograms show a peak in the hydrogen evolution region that suggest the transformation in the adlayer from Fe(II)to Fe(0).In agreement with the coulometric analysis,the voltammetric features in the OH adsorption region would be related with the oxidation to the+3 valence state.The results obtained with LITJ method reflect the existence of a strong interaction of the Fe oxophilic species with the water molecules,shifting the potential of maximum entropy away from the onset of the HER.Hence,the most catalytic surface is the one with the lowest Fe coverage.

Synergetic photocatalytic and thermocatalytic reforming of methanol for hydrogen production based on Pt@TiO_(2) catalyst

In order to efficiently produce H_(2),conventional methanol‐water thermocatalytic(TC)reforming requires a very high temperature due to high Gibbs free energy,while the energy conversion efficiency of methanol‐water photocatalytic(PC)reforming is far from satisfaction because of the kinetic limitation.To address these issues,herein,we incorporate PC and TC processes together in a specially designed reactor and realize simultaneous photocatalytic/thermocatalytic(PC‐TC)reforming of methanol in an aqueous phase.Such a design facilitates the synergetic effect of the PC and TC process for H_(2) production due to a lower energy barrier and faster reaction kinetics.The methanol‐water reforming based on the optimized 0.05%Pt@TiO_(2) catalyst delivers an outstanding H_(2) production rate in the PC‐TC process(5.66μmol H_(2)·g^(‒1) catalyst·s^(‒1)),which is about 3 and 7 times than those of the TC process(1.89μmol H_(2)·g^(‒1) catalyst·s^(‒1))and the PC process(0.80μmol H_(2)·g^(‒1) catalyst·s^(‒1)),respectively.Isotope tracer experiments,active intermediate trapping experiments,and theoretical calculations demonstrate that the photo‐generated holes and hydroxyl radicals could enhance the methanol dehydrogenation,water molecule splitting,and water‐gas shift reaction,while high temperature accelerates reaction kinetics.The proposed PC‐TC reforming of methanol for hydrogen production can be a promising technology to solve the energy and environmental issue in the closed‐loop hydrogen economy in the near future.

Relevance of the P ＆ O MPPT Technique in an Original PV-Powered Water Pumping Application

Many papers exploiting the various MPPT （maximum power point tracking） techniques in PV （photovoltaic） applications, from the simple to the most complicated, can be found in literature. However, these techniques may not always be easy to implement in industrial applications. The main challenge of this paper is to model and implement the P ＆ O （perturb and observe） algorithm in a low-cost PV-powered pumping system. To that end, a comparative investigation of the performance characteristics of the most popular MPPT methods, such as FOCV （fractional open circuit voltage）, FSCC （fractional short circuit current）, FLC （fuzzy logic control）, ANN （artificial neural network） and INC （incremental conductance） is presented. This analysis is helpful to highlight the relevance of the P ＆ O technique taking better account of complexity, difficulty of implementation and cost considerations in water pumping applications. The targeted PV-powered pumping system is based on a single-phase induction motor supplied by a three-phase inverter controlled by the DTC （direct torque control） technique. This stand-alone PV system is dedicated to water pumping, especially in rural areas that have no access to national grids but have sufficient amount of solar radiation. Simulation modeling （Matlab/Simulink） and experimental results are presented to demonstrate the relevance of the system.

Reality of Energy Spectra in Multi-dimensional Hamiltonians Having Pseudo Hermiticity with Respect to the Exchange Operator

The pseudo Hermiticity with respect to the exchange operators of N-D complexHamiltonians is investigated. It is shown that if an N-D Hamiltonian is pseudo Hermitian and anyeigenfunction of it retains π_αT symmetry then the corresponding eigen value is real, where π_αis an exchange operator with respect to the permutation a of coordinates and T is the time reversaloperator. We construct a special class of N-D pseudo Hermitian Hamiltonians with respect to exchangeoperators from both N/2-D and N-D general complex Hamiltonians. Examples are presented forHamiltonians with πT symmetry (π : x reversible y, p_x reversible p_y) and the reality of thesesystems are investigated.

A versatile Pt-Ce6 nanoplatform as catalase nanozyme and NIR-Ⅱ photothermal agent for enhanced PDT/PTT tumor therapy

The hypoxic nature of solid tumors has severely negative effects on oxygen-based photodynamic therapy.In this study,we used porous Pt nanoparticles as a catalase(CAT)nanozyme,the second near-infrared(NIR-Ⅱ)region photothermal transition agents(PTAs),and carriers of photosensitizer chlorin e6(Ce6)to synthesize a composite nanosystem Pt-Ce6.In this system,Pt-Ce6 can continuously and stably decompose H2O2 into oxygen,thereby alleviating tumor hypoxia and improving the effect of photodynamic therapy(PDT).With 650 nm illumination,the reactive oxygen species(ROS)produced by Ce6 will decrease the mitochondrial membrane potential(MMP,ΔΨm)to release cytochrome c(Cyt-c)from the mitochondria into the cytoplasm,eventually leading to mitochondrial-mediated cellular apoptosis during the PDT process.In addition,Pt-Ce6 has good photothermal stability and high photothermal conversion efficiency(52.62%)in the NIR-II region.In U14 tumor-bearing mice,Pt-Ce6 completely suppressed tumor growth and recurrence under laser irradiation.Thus the nanocomposite shows excellent PDT/photothermal therapy(PTT)synergistic performance in vitro and in vivo.

Novel multi-heterostructured Pt-BiOBr/TiO2 nanotube arrays with remarkable visible-light photocatalytic performance and stability

Unique multiple heterojunction of Pt-BiOBr/TiO2 nanotube arrays（Pt-BiOBr/TNTAs） was achived by successively loading both Pt nanoparticles（NPs） and BiOBr nanoflkes（NFs） on surface of ordered and spaced TiO2 nanotubes（NTs） using anodization followed by solvothermal and sequential chemical bath deposition（S-CBD） method. The fabricated Pt-Bi OBr/TNTAs were fully characterized, and the photocatalytic（PC） activity and stability of PtBiOBr/TNTAs toward degradation of methyl orange（MO） under visible-light irradiation（λ＆gt;400 nm） were evaluated. The results reveal that multiple heterostructures of Pt/TiO2, Pt/BiOBr and BiOBr/TiO2 are constructed among TNTAs substrate, Pt NPs and BiOBr NFs, and the hybrid Pt-BiOBr/TNTAs catalyst exhibits remarkable visible-light PC activity, favourable reusability and long-term stability. The combined effect of several factors may contribute to the remarkable PC performance, including strong visible-light absorption by both Pt NPs and BiOBr NFs, lower recombination rate of photo-generated electrons and holes attributed to the multiple heterojunction, microstructures for facile light injection and adsorption as well as efficient mass transport, and larger specific surface area for enhancing light absorption, increasing the effective contact area between the absorbed dye molecules and catalyst and benefiting the molecule transport of reactants or products.

Atomic Decompositions of Triebel-Lizorkin Spaces with Local Weights and Applications

Abstract In this paper, the authors characterize the inhomogeneous Triebel-Lizorkin spaces Fs,w p,q （Rn） with local weight w by using the Lusin-area functions for the full ranges of the indices, and then establish their atomic decompositions for s ∈ R, p ∈ （0, 1] and q ∈ [p, ∞）. The novelty is that the weight w here satisfies the classical Muckenhoupt condition only on balls with their radii in （0, 1]. Finite atomic decompositions for smooth functions in Fs,w p,q（Rn） are also obtained, which further implies that a （sub）linear operator that maps smooth atoms of Fs,w p,q（Rn） uniformly into a bounded set of a （quasi-）Banach space is extended to a bounded operator on the whole Fs,w p,q（Rn） As an application, the baundedness of the local Riesz operator on the space Fs,w p,q（Rn） is obtained.