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Surveys on magnetospheric plasmas based on the Double Star Project (DSP) exploration

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Science china(Technological Sciences) 2008年第10期51卷 1639-1647页

作者： c. P. EScOUBET c. m. cARR H. RmE A. FAZAKERLEY H. LAAKSO I. DANDOURAS m. DUNLOP ESA/ESTEc SCI-SH Keplerlaan 1 2200 AG Noordwijk The Netherlands Imperial college of Science Technology and Medicine London SW7 2BZ United Kingdom cESR BP4346 31028 Toulouse Cedex 4 France mullard Space Science Laboratory Univ. College London Dorking Surrey RH5 6NT United Kingdom Imperial college of Science Technology and Medicine London SW7 2BZ United Kingdom Rutherford Appleton Laboratory Didcot Oxon OX11 0QX United Kingdom

The equatorial and polar satellites of the Double Star Project (DSP) were launched successfully on December 29, 2003 and July 25, 2004, respectively, and both of them are operating smoothly. The DSP provides a good opportunity for investigat-ing the structure of the magnetosphere. Based on the DSP data collected during 2004, we have surveyed the distribution of the magnetic fields and plasmas in the magnetosphere. It is found that: (1) Near the Earth’s equatorial plane within geo-centric distances of less than 7 RE, the Earth’s magnetic field is dipolar. In the vi-cinity of the magnetopause, the magnetic field is enhanced by a factor of about 1.5, and on the nightside, the magnetic field can vary significantly from the Earth’s di-pole field, likely caused by the presence of the near-Earth tail current sheet. (2) In the day-side magnetosheath, the electron and ion densities are usually both in the range of 10―30 cm?3; the ion and electron temperatures are usually about 200 and 50 ev, respectively. The flow pattern is usually smooth, with a low velocity in the subsolar region and with significantly higher velocities in the dawn and dusk flanks. (3) In the region between the magnetopause and plasmasphere the density is low, approximately 0.5―5 cm?3, and the temperature is high, about 1―10 kev for ions and 0.1―5 kev for electrons. The ion temperature has an apparent anisotropy, with the ratio of the perpendicular and parallel temperatures being about 1.0―1.3 for the night- and dusk-side magnetosphere and about 1.3―2.0 for the day- and dawn-side magnetosphere. There is an evident sunward convection of about 50 km/s in the magnetosphere. On the dawn side, the flow becomes somewhat turbulent, and in the vicinity of the night-noon meridian plane, the convection is rather slow. (4) The high-energy electrons with energies higher than 2 mev are mainly located in the regions with 3 ctrons area varies with time, it may expand and shrink

关键词： Earth’s magnetosphere space exploration geomagnetic field space plasmas

Synthesis of a-SnWO_4 thin-film electrodes by hydrothermal conversion from crystalline WO_3

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chinese chemical Letters 2015年第4期26卷 474-478页

作者： Kayla J.Pyper Taylor c.evans Bart m.Bartlett Department of chemistry University of michigan

Thin film electrodes of the orthorhombic form of tin tungstate （α-SnWO4） were prepared using a hydrothermal method to convert thin films of WO3 in aqueous SncI2. The pH dependence of the growth mechanism was identified by scanning electron microscopy （SEm） and X-ray diffraction （XRD）. The XRD patterns show complete conversion of WO3（s） to SnWO4（s） at pH 1, 4, and 7. SEm images reveal a morphology change from sponge-like platelets to sharp nanowires as the pH increases from 1 to 7. The α-SnWO4 thin films were reddish brown in color, and display an indirect band gap of 1.9 ev by diffuse reflectance UV-vis spectroscopy. α-SnWO4 is therefore solar-responsive, and a chopped light linear sweep voltammogram recorded under 100 mW/cm2 Am1.5 simulated solar illumination in a pH 5 0.1 mol/L KPi buffer show a visible light response for photoelectrochemical water oxidation, producing 32 μA/cm2 at 1.23 V vs. RHE.

关键词： Alpha tin tungstateHydrothermal conversionmicrostructureHydrothermal method

Semiconducting properties of aluminum-doped ZnO thin films grown by spray pyrolysis technique

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Journal of Semiconductors 2015年第3期36卷 23-28页

作者： m.A.mahadik Y.m.Hunge S.S.Shinde K.Y.Rajpure c.H.Bhosale Electrochemical materials Laboratory Department of Physics Shivaji University

Highly transparent and preferential c-axis oriented nanocrystalline undoped and A1 doped zinc oxide （AZO） thin films have been deposited onto amorphous glass substrate by spray pyrolysis. The XRD studies reveal that AZO with a hexagonal （wurtzite） crystal structure having （002） preferred orientation is formed. The atomic force microscope （AFm） shows uniform surface topography. The optical band gap values of undoped and AZO thin films were changed from 3.34 to 3.35 ev. The band gap energy and photoluminescence are found to depend on the Al doping. Thermoelectric power measurement shows film having n-type in nature. Dielectric constant and loss （tan δ） were found to be frequency dependent. Interparticle interactions in the deposited films are studied by complex impendence spectroscopy.

关键词： aluminum zinc oxide structural morphological and dielectrical properties

Asphaltene Surface Erosion in Air Plasma

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Plasma Science and Technology 2010年第1期12卷 81-86页

作者： m. VILLA m. cALIXTO-RODRIGUEZ H. mARTINEZ J. c. POVEDA P. G. REYES P. ALTUZAR Faculty of Sciences Autonomous University of the State of Mexico State of Mexico Mexico Institute of Physical Sciences Autonomous National University of Mexico 62210 Cuernavaca Morelos Mexico Energy Research center Autonomous National University of Mexico 62580 Temixco Morelos Mexico

Optical emission spectroscopy was applied for plasma characterization during erosion of substrates of asphaltene. The amount of 100 mg of asphaltene was carefully applied to an electrode and exposed to air plasma glow discharge at a pressure of 1.0 Tort. The plasma was generated in a stainless steel discharge chamber by an Ac generator with a frequency of 60 Hz and an output power of about 60 W. The electron temperature was found to be 6.88 ev, and the ion density is about 3.5×10^16 cm^-3. As the asphaltene was exposed to the air plasma, the surface was etched. The emission from molecular bands cS2,O3, N2^＋, NO, O2, cS, S2, cN, c7H7, c2, H2, c2^-, NiO, N2 and SO, and atomic line O, were observed and some of them were used to monitor the evolution of asphaltene erosion. The asphaltene weight was reduced gradually with an etching rate of about 0.844 mg/min, during the first 20 min.

关键词： optical emission spectroscopy asphaltene erosion

The influence of monomer concentration on the optical properties of electrochemically synthesized polypyrrole thin films

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Journal of Semiconductors 2013年第10期34卷 13-18页

作者： J.V.Thombare m.c.Rath S.H.Han V.J.Fulari Holography and material Research Laboratory Department of PhysicsShivaji UniversityKolhapur-416 004India Radiation and Photochemistry Division BARCMumbaiIndia Department of chemistry Hanyang UniversitySeoulSouth Korea

Polypyrrole （PPy） thin films were deposited on stainless steel and ITO coated glass substrate at a constant deposition potential of 0.8 V versus saturated calomel electrode （ScE） by using the electrochemical polymerization method. The PPy thin films were deposited at room temperature at various monomer concentrations ranging from 0.1 m to 0.3 m pyrrole. The structural and optical properties of the polypyrrole thin films were investigated using an X-ray diffractometer （XRD）, FTIR spectroscopy, scanning electron microscopy （SEm）, and ultravioletvisible （UV-vis） spectroscopy. The XRD results show that polypyrrole thin films have a semi crystalline structure. Higher monomer concentration results in a slight increase of crystallinity. The polypyrrole thin films deposited at higher monomer concentration exhibit high visible absorbance. The refractive indexes of the polypyrrole thin films are found to be in the range of 1 to 1.3 and vary with monomer concentration as well as wavelength. The extinction coefficient decreases slightly with monomer concentration. The electrochemically synthesized polypyrrole thin film shows optical band gap energy of 2.14 ev.

关键词： polypyrrole electrochemical polymerization method structure optical properties

The sprayed ZnO films: nanostructures and physical parameters

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Journal of Semiconductors 2015年第8期36卷 30-36页

作者： m.Benhaliliba A.Tiburcio-Silver A.Avila-Garcia A.Tavira Y.S.Ocak m.S.Aida c.E.Benouis material Technology Department Physics Faculty USTO-MB University ITT-DIE cinvestav-IPN Department of Ingeniería Eléctrica-SEES Dicle University Education Faculty Science Department Thin Films & Plasma Lab Physics Department Mentouri University

We synthesized the pure and indium-doped （IZO） ZnO films with a facile composition control spray pyrolysis route. The substrate temperature （Ts） and In-doping effects on the properties of as-grown films are inves- tigated. The X-ray pattern confirms that the as-synthesized ZnO phase is grown along a （002） preferential plane. It is revealed that the crystalline structure is improved with a substrate temperature of 350 ℃ moreover, the morphol- ogy of as-grown films, analyzed by AFm, shows nanostructures that have grown along the c-axis. The （3 ×3 μm2） area scanned AFm surface studies give the smooth film surface RmS 〈 40 nm. The UV-VIS-IR measurements reveal that the sprayed films are highly transparent in the visible and IR bands. The photoluminescence analysis shows that the strong blue and yellow luminescences of 2.11 and 2.81 ev are emitted from ZnO and IZO films with a slight shift in photon energy caused by In-doping. The band gap is a bit widened by In-doping, 3.21 ev （ZnO） and 3.31 ev （IZO） and the resistivity is reduced from 385 to 8Ω·m. An interesting result is the resistivity linear dependence on the substrate temperature of pure ZnO films.

关键词： sprayed ZnO films deposition temperature AFm observation photoluminescence emission resis- tivity

Effect of RF power on the structural and optical properties of ZnS thin films prepared by RF-sputtering

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Journal of Semiconductors 2018年第12期39卷 26-31页

作者： c.m.Samba Vall m.chaik H.Ait Dads H.El Aakib m.Elyaagoubi m.Aggour A.Outzourhit Laboratory of Nanomaterials for Energies and Environments Faculty of Sciences Semlalia Cadi Ayyad University Laboratory of Renewable Energy and Environment Faculty of Science Kenitra Ibn Tofail University

Zinc sulphide(ZnS) thin films have grown on glass and Si substrates by reactive cathodic radio frequency(RF) sputtering. The RF power was varied in the range of 100 to 250 W, while the deposition time is set at75 min. The optical, structural, and morphological properties of these thin films have been studied. The optical properties(mainly thickness, refractive index,absorption coefficient, and optical band gap) were investigated by optical transmittance measurements in the wavelength range of ultraviolet-visible-near infrared spectroscopy and spectroscopy infrared with Fourier transform. Fourier(FT-IR) and XRD analysis indicated that all sputtering ZnS films had a single-phase with a preferred orientation along the(111) plane of the zinc sphalerite phase(ZB). The crystallite size ranged from 11.5 to 48.5 nm with RF power getting a maximum of 200 W. UV-visible measurements exhibited that the ZnS film had more than 80% transmission in the visible wavelength region. In addition, it has been observed that the band gap energy of ZnS films is decreased slightly from 3.52 to 3.29 ev, and as the RF power is increased, the film thickness increases with the speed of deposit growth. Scanning electron microscopy observations revealed the types of smooth-surfaced films. The measurements(FT-IR) revealed at wave number1118 and 465.02 cmabsorption bands corresponding to the symmetrical and asymmetric vibration of the Zn-S stretching mode. X-ray reflectometry measurements of ZnS films have shown that the density of the films is(3.9 g/cm~3) close to that of solid ZnS.

关键词： ZnS thin films by sputtered RF-sputtering ZnS ZnS buffer layer for solar cell

The effects of electron irradiation on the optical properties of the organic semiconductor polypyrrole

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Journal of Semiconductors 2013年第9期34卷 11-15页

作者： J.V.Thombare m.c.Rath S.H.Han V.J.Fulari Holography and materials Research Laboratory Department of PhysicsShivaji University Radiation and Photochemistry Division BARC Department of chemistry Hanyang University

The optical properties of polypyrrole （Ppy） thin films upon 2 mev electron beam irradiation changes with different doses. The induced changes in the optical properties for Ppy thin films were studied in the visible range 300 to 800 nm at room temperature. The optical band gap of the pristine Ppy was found to be 2.19 cV and it decreases up to 1.97 ev for a 50 kGy dose of 2 mev electron beam. The refractive index dispersion of the samples obeys the single oscillator model. The obtained results suggest that electron beam irradiation changes the optical parameters of Ppy thin films.

关键词： polypyrrole electron beam irradiation optical band gap

The Fusability of Erythrocytes as a method for evaluating the Instability of Their membranes

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Open Journal of Biophysics 2013年第3期3卷 198-200页

作者： Yury A. Sheremet’ev Aleksandra N. Popovicheva methun m. Rogozin Gregory Y. Levin Nizhny Novgorod Scientific Research Institute of Traumatology and Ortopedics Nizhny Novgorod Russia

A novel approach to the study of erythrocytes instability based on assessment fusability of their plasma membrane is presented. The fusability of erythrocytes normal blood, stored for 7 days at 4°c, and type 2 patients with diabetes were studied. Human erythrocytes were fused by incubation with La3+ at final concentrations from 50 to 200 μm. Erythrocytes aggregates were incubated at 37°c for 120 min. The fusability of erythrocytes was evaluated using a light microscope. It was shown that La3+ induced extensive fusion of erythrocytes after 7 days of blood storage and erythrocytes of patients with diabetes. Incubation of normal erythrocytes at 37°c for 120 min does not induce cell fusion.

关键词： Erythrocytes Fusability membrane Instability La3+