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Chinese physics B 2015年第10期24卷 432-437页

作者：王小波李勇闫玲玲李新建 department of physics and Laboratory of Material physics Zhengzhou University College of physics and Electrical engineering Anyang Normal University department of physics Pingdingshan University

A GaN/Si nanoheterojunction is prepared through growing Ga N nanocrystallites（nc-GaN） on a silicon nanoporous pillar array（Si-NPA） by a chemical vapor deposition（CVD） technique at a relatively low temperature. The average size of nc-Ga N is determined to be ~10 nm. The spectral measurements disclose that the photoluminescence（PL） from GaN/SiNPA is composed of an ultraviolet（UV） band and a broad band spanned from UV to red region, with the feature that the latter band is similar to that of electroluminescence（EL）. The electron transition from the energy levels of conduction band and, or, shallow donors to that of deep acceptors of Ga N is indicated to be responsible for both the broad-band PL and the EL luminescence. A study of the I-V characteristic shows that at a low forward bias, the current across the heterojunction is contact-limited while at a high forward bias it is bulk-limited, which follows the thermionic emission model and space-charge-limited current（SCLC） model, respectively. The bandgap offset analysis indicates that the carrier transport is dominated by electron injection from n-GaN into the p-Si-NPA, and the EL starts to appear only when holes begin to be injected from Si-NPA into GaN with biases higher than a threshold voltage.

关键词： GaN/Si-NPA heterojunction rectification electroluminescence (EL)

Room Temperature Ferromagnetism in Dual Doped (Mn^(2+), Ni^(2+)) ZnO Codoped with Li^(1+) Prepared Using EDTA Sintered at Low Temperature

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Journal of Materials Science & Technology 2014年第3期30卷 275-279页

作者： R.Pugaze A.Sivagamasundari D.Vanidha S.Chandrasekar A.Arunkumar S.Rajagopan R.Kannan department of physics Pondicherry Engineering College department of Chemistry Pondicherry Engineering College

Nanopowders of Znl_x_y_zMnxNiyLizO [（x = 0.04, y = 0, z = 0）, （x = 0.04, y = 0.03, z = 0） and （x = 0.04, y = 0.03, z = 0.03）] have been synthesized by sol-gel precursor route using ethylene diamine tetraacetic acid （EDTA） as a metal chelating agent. X-ray diffraction analysis confirms the formation of wurtzite hexagonal structure for all the three compositions. Mn2＋ doped ZnO exhibits room temperature ferromagnetism （RTFM）, and it is found that further Ni2＋ doping has decreased Ms because of limit of solid solubility of transition metal in ZnO. But codoping of monovalent Li1＋, further increases the ferromagnetism （FM） value, due to introduction of free carriers compared to the dual doped samples. Photoluminescence （PL） spectra of the system, exhibit near band edge （NBE） emission peak at --464 nm due to the electron transition from interstitials to the valence band. Recombination of conduction electron with hole trapped at oxygen vacancy, leads to prominent defect emission peaks at --482 nm and 532 nm. The evidence of the formation of metaI-EDTA complexes are found from the Fourier transform infrared spectra at 2800-3800 cm-1 with shifting, splitting of the peak and also drastic variations in the intensity.

关键词： Mn-doped Dual doped Li codoped Ferromagnetism Photoluminescence Fourier transform infrared (FTIR) spectroscopy

Locally Enhanced Flow and Electric Fields Through a Tip Effect for Efficient Flow‑Electrode Capacitive Deionization

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Nano-Micro Letters 2025年第2期17卷 1-17页

作者： Ziquan Wang Xiangfeng Chen Yuan Zhang Jie Ma Zhiqun Lin Amor Abdelkader Maria‑Magdalena Titirici Libo Deng College of Chemistry and Environmental engineering Shenzhen UniversityShenzhen 518060People’s Republic of China Research Center for Environmental Functional Materials College of Environmental Science and EngineeringTongji University1239 Siping RoadShanghai 200092People’s Republic of China department of Chemical and Biomolecular engineering National University of SingaporeSingapore 117585Singapore department of engineering Faculty of Science and TechnologyBournemouth UniversityTalbot CampusFern BarrowPooleEngland BH125BBUK Institut de Chimie de Nice UniversitéCôte d’AzurUMR CNRS 727228 Av.Valrose06108 NiceFrance department of Chemical engineering Imperial College LondonSouth Kensington CampusExhibition RdLondon SW72AZUK

Low-electrode capacitive deionization(FCDI)is an emerging desalination technology with great potential for removal and/or recycling ions from a range of ***,it still suffers from inefficient charge transfer and ion transport kinetics due to weak turbulence and low electric intensity in flow electrodes,both restricted by the current ***,a new tip-array current collector(designated as T-CC)was developed to replace the conventional planar current collectors,which intensifies both the charge transfer and ion transport *** effects of tip arrays on flow and electric fields were studied by both computational simulations and electrochemical impedance spectroscopy,which revealed the reduction of ion transport barrier,charge transport barrier and internal *** the voltage increased from 1.0 to 1.5 and 2.0 V,the T-CC-based FCDI system(T-FCDI)exhibited average salt removal rates(ASRR)of 0.18,0.50,and 0.89μmol cm^(-2) min^(-1),respectively,which are 1.82,2.65,and 2.48 folds higher than that of the conventional serpentine current collectors,and 1.48,1.67,and 1.49 folds higher than that of the planar current ***,with the solid content in flow electrodes increased from 1 to 5 wt%,the ASRR for T-FCDI increased from 0.29 to 0.50μmol cm^(-2) min^(-1),which are 1.70 and 1.67 folds higher than that of the planar current ***,a salt removal efficiency of 99.89%was achieved with T-FCDI and the charge efficiency remained above 95%after 24 h of operation,thus showing its superior long-term stability.

关键词： Flow-electrode Capacitive deionization Current collector Tip effect Desalination

Wave function for the squeezed atomic coherent state in entangled state representation and some of its applications

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Chinese physics B 2010年第1期19卷 326-331页

作者：王继锁孟祥国梁宝龙 College of physics and engineering Qufu Normal University department of physics Liaocheng University

Based on the Einstein, Podolsky, and Rosen （EPR） entangled state representation, this paper introduces the wave function for the squeezed atomic coherent state （SACS）, which turns out to be just proportional to a single-variable ordinary Hermite polynomial of order 2j. As important applications of the wave function, the Wigner function of the SACS and its marginal distribution are obtained and the eigenproblems of some Hamiltonians for the generalized angular momentum system are solved.

关键词： squeezed atomic coherent state entangled state representation Wigner function eigen- value and eigenstate

Simulation of ECR Startup and Comparison with Experimental Observations in SUNIST

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Plasma Science and Technology 2011年第1期13卷 30-35页

作者：谭熠高喆王龙 department of engineering physics Tsinghua University Institute of physics Chinese Academy of Sciences

Transient process of ECR startup in SUNIST is analyzed and simulated in a one- dimensional model. Contributions from the generation, drift, diffusion and loss of electrons are taken into account in the model and estimated from experimental parameters, e.g., toroidal field, vertical field and gas filling pressure. Typical discharges are simulated with the conditions close to the experimental ones. Experimental and simulated results are comparable qualitatively in amplitudes and semi-quantitatively in time. From the results it is confirmed that the transient process of ECR startup ill SUNIST is dominated, as preliminarily deduced from experimental observations, by a pair of exclusive factors, namely the absorption, due to gas ionization, and the reflection of microwave, caused by the shift of over dense plasmas due to outward E x B drift. In addition to these two factors, electron loss along the field line is also very important in determining the character of discharges.

关键词： spherical tokamak non-inductive startup electron cyclotron resonance (ECR)

High permittivity and low dielectric loss analysis of lead free Sr_(1-x)La_x(Ti_(0.5) Fe_(0.5))O_3

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Journal of Central South University 2013年第12期20卷 3363-3371页

作者： M.R.Shah A.K.M.Akther Hossain department of physics Primeasia University department of physics Bangladesh University of Engineering and Technology

The structural and electrical properties of lead free Srx-xLax（***.5）O3 （SLTFO） prepared by standard solid state reaction technique were studied. The X-ray diffraction analysis confirmed the formation of a single-phase cubic perovskite structure. The compositional dependence of lattice constant, density and microstructural studies show that they vary significantly with La3＋ content. When measured at 10 kHz, all the compositions of SLTFO at room temperature exhibit a high permittivity （about 104） and low dielectric loss （about 10-3）. SLTFO also display minimum dielectric loss within the lower and higher limits of frequency, indicating that the samples are of good quality. It is concluded from the calculated ac conductivity that the conduction is due to mixed polarons hopping. The complex impedance plot exhibits a tendency of forming a single semicircular arc for all compositions, which implies a dominance of grain boundary resistance on the impedance. Impedance parameters were determined by fitting the experimental data with Cole-Cole empirical formula. The results of the present experiment indicate that the lead free SLTFO materials with higher permittivity and lower dielectric loss have possible practical applications.

关键词： dielectric properties solid state reaction Sr titanate X-ray diffraction

A new finite-dimensional thermal coherent state and its Wigner distribution function

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Chinese physics B 2011年第1期20卷 371-376页

作者：孟祥国王继锁梁宝龙 department of physics Liaocheng University College of physics and engineering Qufu Normal University

This paper constructs a new type of finite-dimensional thermal coherent states （FDTCS）, which differs from the proceeding thermal coherent state in construction, as realisations of SU（2） Lie algebra. Using the technique of integration within an ordered product of operator, it investigates the orthonormality and completeness relation of the FDTCS. Based on the thermal Wigner operator in the thermal entangled state representation, the Wigner function of the FDTCS is obtained. The nonclassical properties of the FDTCS are discussed in terms of the negativity of its Wigner function.

关键词： new finite-dimensional thermal coherent state thermal entangled state representation Wigner distribution function

Shaping of few-cycle laser pulses via a subwavelength structure

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Chinese physics B 2013年第9期22卷 450-455页

作者：郭亮谢小涛詹志明 department of physics Northwest University School of physics and Information engineering Jianghan University

We theoretically investigate the propagation of few-cycle laser pulses in resonant two-level dense media with a sub- wavelength structure, which is described by the full Maxwell-Bloch equations without the frame of slowly varying envelope and rotating wave approximations. The input pulses can be shaped into shorter ones with a single or less than one optical cycle. The effect of the parameters of the subwavelength structure and laser pulses is studied. Our study shows that the media with a subwavelength structure can significantly shape the few-cycle pulses into a subcycle pulse, even for the case of chirp pulses as input fields. This suggests that such subwavelength structures have potential application in the shaping of few-cycle laser pulses.

关键词： ultrashort pulses coherent propagation self-induced transparency

Response of multi-step compound pre-equilibrium reaction cross sections for the(p,n)reactions to forms of optical model parameters

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Nuclear Science and Techniques 2017年第10期28卷 65-70页

作者： Felix S.Olise Oludaisi I.Oladunjoye Afis Ajala Sunday D.Olorunfunmi Hezekiah B.Oianiyi department of physics and engineering physics ObafemiAwolowo UniversityIle-Ife220005Nigeria

In furtherance to improving agreement between calculated and experimental nuclear data, the nuclear reaction code GAMME was used to calculate the multistep compound(MSC) nucleus double differential cross sections(DDCs) for proton-induced neutron emission reactions using the Feshbach-Kerman-Koonin(FKK) formalism. The cross sections were obtained for reactor structural materials involving ^(52)Cr(p, n)^(52)Mn,^(56)Fe(p,n)^(56)Co, and ^(60)Ni(p, n)^(60)Cu reactions at 22.2 MeV incident energy using the zero-range reaction mechanism. Effective residual interaction strength was 28 MeV, and different optical potential parameters were used for the entrance and exit channels of the proton-neutron interactions. The calculated DDCs were fitted to experimental data at the same backward angle of 150°, where the MSC processes dominate. The calculated and experimental data agree well in the region of pre-equilibrium(MSC) reaction dominance against a weaker fit at the lower emission energies. We attribute underestimations to contributions from the other reaction channels and disagreement at higher outgoing energies to reactions to collectively excited states. Contrary to the FKK multi-step direct calculations, contributions from the higher stages to the DDCs are significant. Different sets of parameters resulted in varying levels of agreement of calculated and experimental data for the considered nuclei.

关键词：反应截面光学势参数预平衡模型参数多步复合相互作用强度实验数据

Electronic transport properties of phenylacetylene molecular junctions

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Chinese physics B 2011年第10期20卷 384-389页

作者：刘文程杰闫翠霞李海宏王永娟刘德胜 physics and Information engineering department Jining University School of physics Shandong University

Electronic transport properties of a kind of phenylacetylene compound-- （4-mercaptophenyl）-phenylacetylene are calculated by the first-principles method in the framework of density functional theory and the nonequilibrium Green＇s function formalism. The molecular junction shows an obvious rectifying behaviour at a bias voltage larger than 1.0 V. The rectification effect is attributed to the asymmetry of the interface contacts. Moreover, at a bias voltage larger than 2.0 V, which is not referred to in a relevant experiment [Fang L, Park J Y, Ma H, Jen A K Y and Salmeron M 2007 Langmuir 23 11522], we find a negative differential resistance phenomenon. The negative differential resistance effect may originate from the change of the delocalization degree of the molecular orbitals induced by the bias.

关键词： phenylacetylene compound electronic transport rectification