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1.
A. A. Krasilnikov Yu. Yu. Kulikov V. G. Ryskin L. I. Fedoseev 《Radiophysics and Quantum Electronics》1998,41(11):953-964
We describe the equipment and methods of observation of variation of the state of some stratospheric and mesospheric gas components
and present the results of measurements of the time and space ozone variations at altitudes of from 20 to 70 km above Nizhny
Novgorod: the seasonal and diurnal variation and “ozone clouds.” The seasonal variation of ozone content at altitudes exceeding
22 km and the vertical distribution of ozone are compared with the measurement results obtained from the TOMS and CRISTA satellites.
We also show the results of observations of mesospheric carbon monoxide.
Institute of Applied Physics of the Russian Academy of Sciences. Nizhny Novgorod, Russia. Translated from Izvestiya Vysshikh
Uchebnykh Zavedenii, Radiofizika, Vol. 41, No. 11, pp. 1405–1423, November, 1998. 相似文献
2.
J. S. Mandeep S. I. S. Hassan 《International Journal of Infrared and Millimeter Waves》2008,29(3):225-231
Based on radar range height indicator (RHI) measurements, cloud characteristics in relation to radiowave propagation over
three locations in different geographical region in western Malaysia have been presented. It is seen that low cloud occurrence
over these locations are quite significant. Cloud attenuation and noise temperature can result in serious degradation of telecommunication
link performances. This paper presents cloud coverage in different months, 0°C isotherm height and cloud attenuation results
at 12 GHz, 20 GHz, 36 GHz, 50 GHz, 70 GHz and 100 GHz over measurement site. The low level cloud over the measurement sites
has been found to occur for many days and nights and particularly in the months of April to May and October to December. Such
results are useful for satellite communication and remote sensing application in Malaysia. 相似文献
3.
We have experimentally studied the characteristic features of a laser beam, polarized at angles of ± 45° to the horizontal
(vertical), passing through plates of varying thickness cut from a CdP2 crystal and placed between crossed polarizers, as a function of their angle of rotation relative to the vertical axis. We
show that a periodic variation in the intensity is connected with the variation in polarization of the laser beam. We have
established that the laser beam remains linearly polarized not only when it passes through the sample along the optic axis,
but also when it travels at up to a 17.5° angle to the optic axis. In this case, the specific rotation of the plane of polarization
along the optic axis is 68.2 degrees/mm for a thicker plate and 83.3 degrees/mm for a thin plate.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 5, pp. 690–693, September–October, 2006. 相似文献
4.
Summary Time series analyses of measurements of total ozone make possible an in-depth climatological study of this important stratospheric
gas. The Italian Air Force's Vigna di Valle Observatory (42°N, 12°E, 262 m a.s.l.) provided a time series of monthly averages
(January 1958–December 1988) of total ozone. Spectral analysis and running averages were combined to detect medium-(QBOs of
estimated (4÷5) DU amplitudes) and long-term fluctuations (possible correlation to 11-year solar cycle) and to filter them,
leaving any overlapping trends unaltered. Total ozone trend estimates produced by the present study were +0.1% per decade
for the 1959–1987 period and a decrease of −0.4% per decade for the more recent 1970–1987 span, over which a pronounced ozone
depletion caused mainly by CFCs is assumed.
This study has supported by the CNR-ENEL Project ?Interaction of energy system with human health and environment?. 相似文献
5.
We discuss the discrepancy between experimental and calculated values of attenuation in water vapor, which is observed for
a sufficiently low tropospheric temperature (of the order of −30°C). We indicate the high correlation of excessive attenuation
with the quadratic component of tropospheric humidity.
Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia. Translated from Izvestiya Vysshikh Uchebnykh
Zavedenii, Radiofizika, Vol. 40, No. 12, pp. 1479–1488, December, 1997. 相似文献
6.
利用NCEP-DOE Reanalysis 2 1979-2009年位势高度场、温度场、湿度场和风场逐日再分析资料,采用考虑面积权重的区域多要素最优分割法,对东亚地区大气环流的季节进行划分,并分析了四季起始时间的时空变化特征.研究结果表明:1)东亚地区春季最早始于中高纬地区的平流层和副热带的对流层中下层;夏季最早始于中高纬的平流层和副热带、中纬度地区的对流层中上层;秋、冬季开始最早的地区集中在东亚地区东部和东北部的对流层中低层,以及中高纬的平流层. 2)季节变化与环流形势密切相关,且对流层各个层次的夏季和冬季起始时间的分布均有较好的垂直一致性,平流层与对流层各季节起始时间分布有较大的差异性,平流层中层和下层也并不一致. 3)华北地区四季平均起始时间距平序列的逐年演变特征表明近30年该地区出现了6个四季起始时间异常偏早的年份,与El Niño活跃年份相一致,反映了海温等外强迫对大气环流季节变化的影响.
关键词:
季节划分
东亚地区
区域多要素最优分割法 相似文献
7.
Summary High-speed solar-wind streams coming from coronal holes produce, in the interplanetary space, a quasi-stationary modulation
of galactic cosmic rays. The Rome cosmic-ray group has analysed this modulation taking into account not only the charged-particle
isotropic intensity but also the North-South anisotropy (A
NS), derived from ground-based measurements. The obtained results for the period October 1964–December 1987 are summarized.
Data from the Bartels solar rotation no. 2034 (May 23–June 18, 1982) are used to illustrate theA
NS phenomenology.
Paper presented at the V Cosmic Physics National Conference, S. Miniato, November 27–30, 1990. 相似文献
8.
The effect of solar features on geospheric conditions leading to geomagnetic storms (GMSs) with planetary index,A
P ≥ 20 and the range of horizontal component of the Earth’s magnetic fieldH such that 250γ <H < 400γ has been investigated using interplanetary magnetic field (IMF), solar wind plasma (SWP) and solar geophysical data
(SGD) during the period 1978–99. Statistically, it is observed that maximum number of GMSs have occurred during the maximum
solar activity years of 21st and 22nd solar cycles. A peculiar result has been observed during the years 1982, 1994 when sunspot
numbers (SSNs) decrease very rapidly while numbers of GMSs increase. No distinct association between yearly occurrence of
disturbed days and SSNs is observed. Maximum number of disturbed days have occurred during spring and rainy seasons showing
a seasonal variation of disturbed days. No significant correlation between magnitude (intensity) of GMSs and importance ofH
α
, X-ray solar flares has been observed. Maximum number of GMSs is associated with solar flares of lower importance, i.e.,
SF during the period 1978-93.H
α
, X-ray solar flares occurred within lower helio-latitudes, i.e., (0–30)°N to (0–30)°S are associated with GMSs. NoH
α
, X-ray solar flares have occurred beyond 40°N or 40°S in association with GMSs. In helio-latitude range (10–40)°N to (10–40)°S,
the 89.5% concentration of active prominences and disappearing filaments (APDFs) are associated with GMSs. Maximum number
of GMSs are associated with solar flares. Coronal mass ejections (CMEs) are related with eruptive prominences, solar flares,
type IV radio burst and they occur at low helio-latitude. It is observed that CMEs related GMS events are not always associated
with high speed solar wind streams (HSSWSs). In many individual events, the travel time between the explosion on the Sun and
maximum activity lies between 58 and 118 h causing GMSs at the Earth. 相似文献
9.
K.Madhavi Latha 《Journal of Quantitative Spectroscopy & Radiative Transfer》2004,84(2):207-213
EP/TOMS satellite-derived aerosol index (AI) data have been analyzed over typical tropical urban environment corresponding to Hyderabad, India to study seasonal and annual distribution of UV-absorbing aerosols. Observations reveal that UV-absorbing aerosol loading is highly seasonal. During the years 1987, 1991 and 1992 high concentration of UV-absorbing aerosols into the atmosphere over Hyderabad region has been observed. UV-absorbing aerosols are high during summer period. Ground-based measurements of aerosol optical depth (AOD) and satellite-derived AI showed good correlation with AOD at . 相似文献
10.
E. Keppler M. Fr?nz M. K. Reuss J. B. Blake R. Seidel J. J. Quenby 《Il Nuovo Cimento C》1996,19(6):915-920
Summary Measurements with the EPAC energetic-charged-particle instrument aboard Ulysses show between −15° and −65° ions and, to some
extent, also electrons apparently accelerated by shocks associated with a cororating interaction region (CIR) operating at
low latitudes. Particles could have reached Ulysses along magnetic-field lines which connect to the shocks in the more distant
heliosphere. Such connections evidently do not exist above −65°. Between the recurrent streams we find the underlying composition
to be similar to that of the anomalous component of cosmic rays (ACR). One channel (ELH), sensitive also to high-energy protons
(E>210 MeV), shows that, superimposed to the large-scale heliospheric modulation of galactic ions, a 26-day variation of the
flux is observed. Such modulation is also observed for the ACR, in phase with the galactic particle modulation, but anticorrelated
to the CIR-related low-energy particles. An estimate of the latitudinal and radial gradients of the galactic cosmic rays at
1 GV gives +0.4%/degree and −11%/AU, respectively.
Paper presented at the Special Session on the Ulysses mission of the XXIV International Cosmic-Ray Conference, Rome, August
28–September 8, 1995. 相似文献
11.
F. Chen L. Liu Z. Shen G.Q. Xu T.S.A. Hor 《Applied Physics A: Materials Science & Processing》2002,74(2):317-319
Free-standing and supported hydrogenated amorphous carbon films (a:C–H) were prepared upon pyrolysis of the polymer formed
by ethanolamine (EA) and citric acid (CA), under an ambient atmosphere at 300 °C. EA facilitates the formation of the macroscopic
films, while CA is essential for obtaining the a:C–H microstructure, which comprises a mixture of sp2 and sp3 carbon.
Received: 29 May 2001 / Accepted: 17 August 2001 / Published online: 20 December 2001 相似文献
12.
L. Pintilie I. Pintilie D. Petre T. Botila M. Alexe 《Applied Physics A: Materials Science & Processing》1999,69(1):105-109
Thermally stimulated current (TSC) measurements performed in the 100 K–400 K temperature range on Bi4Ti3O12 (BiT) thin films annealed at 550 °C and 700 °C had revealed two trapping levels having activation energies of 0.55 eV and
0.6 eV. The total trap concentration was estimated at 1015 cm−3 for the samples annealed at 550 °C and 3×1015 cm−3 for a 700 °C annealing and the trap capture cross-section was estimated about 10−18 cm2. From the temperature dependence of the dark current in the temperature range 20 °C–120 °C the conduction mechanism activation
energy was found to be about 0.956–0.978 eV. The electrical conductivity depends not only on the sample annealing temperature
but also whether the measurement is performed in vacuum or air. The results on the dark conductivity are discussed considering
the influence of oxygen atoms and oxygen vacancies.
Received: 28 January 1998 / Accepted: 8 January 1999 / Published online: 5 May 1999 相似文献
13.
We have studied multiple regressions between the spectral aerosol extinction coefficient ε, backscatter indicatrix gπ, and light-scattering coefficients βθ at angles of θ = 1–180°, which we used to select the optimal scattering angle for determining the extinction coefficient
at the wavelengths 0.350, 0.532, and 1.060 μm. We have estimated the errors in determination of the values of ε and gπ at the given wavelengths for different atmospheric situations with different meteorological parameters. We have shown that
it is possible to use the spectral βθ values at a 33° angle to determine the reference values for ε(λ) and gπ(λ) at λ = 0.350, 0.532, and 1.060 μm in laser detection and ranging (lidar) measurements, and we give examples of recovering
the vertical profiles of ε in a slightly turbid atmosphere from the results of simultaneous multiwavelength lidar and nephelometric
measurements.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 6, pp. 767–772, November–December, 2007. 相似文献
14.
Perception of virtual sound sources moving in the range of elevation from −45° to 45° (at zero azimuth) was studied with participation
of listeners aged 57–73. The virtual sound source trajectory was created using nonindividualized head-related transfer functions
and artificially synthesized spectral components specific to these functions. The percentage of correct responses in determining
the direction of virtual motion depended on the way of imitation by increasing from low to high for the following succession
of imitation methods: (i) displacement of the spectral minimum of broadband noise pulses within a frequency band of 5–12 kHz
(the minimum retained a constant width of 1 kHz), (ii) variation of the spectral minimum width of noise pulses within 6–12
kHz, (iii) variation of the spectral maximum width within 4–8 kHz, (iv) simultaneous variation of the spectral minimum and
maximum widths, (v) displacement of the spectral minimum and simultaneous variation of the spectral maximum width, and (vi)
displacement of the spectral minimum and simultaneous variation of the spectral maximum width and power. For the latter stimulus,
the mean percentage of correct responses (90 ± 5)% did not differ from the corresponding percentage (94 ± 3)% observed for
the stimulus that was synthesized on the basis of nonindividualized head-related transfer functions and used as reference
in synthesizing the spectral components. 相似文献
15.
Konstantin Tarasov Patricia Beaunier Michel Che Eric Marceau Yanling Li 《Journal of nanoparticle research》2011,13(5):1873-1887
Following procedures formerly developed for the preparation of supported heterogeneous catalysts, carbon-coated cobalt nanoparticles
dispersed on porous alumina have been prepared by impregnation of γ-Al2O3 with (NH4)2[Co(EDTA)] and thermal decomposition in inert atmosphere. Below 350 °C, Co(II) ions are complexed in a hexa-coordinated way
by the EDTA ligand. The thermal treatment at 400–900 °C leads to the EDTA ligand decomposition and recovering of the support
porosity, initially clogged by the impregnated salt. According to X-ray absorption spectroscopy, and due to in situ redox
reactions between the organic ligand and Co(II), both oxidic and metallic cobalt phases are formed. Characterisation by transmission
electron microscopy, X-ray diffraction and magnetic measurements reveals that an increase in the treatment temperature leads
to an increase of the degree of cobalt reduction as well as to a growth of the cobalt metal particles. As a consequence, the
samples prepared at 400–700 °C exhibit superparamagnetism and a saturation magnetisation of 1.7–6.5 emu g−1 at room temperature, whilst the sample prepared at 900 °C has a weak coercivity (0.1 kOe) and a saturation magnetisation
of 12 emu g−1. Metal particles are homogeneously dispersed on the support and appear to be protected by carbon; its elimination by a heating
in H2 at 400 °C is demonstrated to cause sintering of the metal particles. The route investigated here can be of interest for obtaining
porous magnetic adsorbents or carriers with high magnetic moments and low coercivities, in which the magnetic nanoparticles
are protected from chemical aggression and sintering by their coating. 相似文献
16.
Summary Past observations and present models of the solar-wind controlled dayside Pc 3-Pc 4 pulsations are reviewed. A year-long comparison
between solar-wind parameters obtained from IMP-8 and micropulsation measurements made at L'Aquila is presented. This study
shows that at low latitudes the relationship between the two phenomena is more clear than at high latitudes. In particular,
in agreement with the upstream-wave source mechanism, different frequency regimes of pulsations can be related to different
regions of the high-velocity streams. Some examples of spectacular wave trains, with unusual amplitude and period, occurred
during the strong geomagnetic storm of March 13, 1989 are also presented.
Paper presented at the V Cosmic Physics National Conference, S. Miniato, November 27–30, 1990. 相似文献
17.
ZnO nanoparticles were synthesized by a sol–gel calcination process following being annealed in air at 400, 600, 800 and 1000°C.
X-ray diffraction pattern and X-ray photoelectron spectroscopy show that all the samples present a typical wurtzite structure
and no other impurity phases are observed. Room-temperature ferromagnetism from all the samples is confirmed by the vibrating
sample magnetometer measurements, which shows that the RTFM decreases with the annealing temperature increasing from 400 to
800°C, and then became larger for the sample annealed at 1000°C. According to the Raman scattering spectra and electron paramagnetic
resonance, the RTFM of samples annealed at 600, 800 and 1000°C might be related to the oxygen vacancy related defects. However,
the RTFM from the sample annealed at 400°C, presenting nearly the same value as that of the sample annealed at 1000°C, could
originate with the interstitial zinc defects associated with XPS and photoluminescence analyses. 相似文献
18.
The recently discovered compound LiFeVO4 was prepared by solid-state reaction at 570 °C during a 7-h period. The X-ray diffraction pattern revealed an orthorhombic
crystal structure. Thermogravimetric measurements revealed a reversible mechanism which was attributed to absorption–desorption
of humidity. Impedance spectroscopy measurements were carried out at 25 °C steps in the temperature range from 25 to 500 °C
and equivalent circuits were drawn to fit the impedance measurement results at each temperature level. The elements of the
equivalent circuits were assigned to bulk, grain boundary, and along grain boundary conductivity. All three conduction mechanisms
were found to be humidity sensitive. Arrhenius plots were plotted for the bulk and grain boundary conductivity processes.
The activation energy for the bulk conductivity process was calculated to be 0.25 eV over the temperature range from 175 to
500 °C and the activation energy for the grain boundary conductivity process was calculated to be 0.41 eV from 300 to 500 °C
and 0.20 eV from 175 to 275 °C. An explanation for the existence of these two grain boundary activation energies is attempted.
The dependence of the material conductivity mechanisms on humidity suggests that LiFeVO4 could be used as a humidity sensor. 相似文献
19.
V. V. Borog E. I. Yakovleva 《Bulletin of the Russian Academy of Sciences: Physics》2011,75(6):758-760
A new method of searching for high-energy solar neutrons using the ground-based TEMP muon hodoscope with a high angular resolution
of ∼1°–2° is considered. An excess in the muon flux (about four standard deviations) was observed during solar flare GLE 60
(April 15, 2001). A small excess in the permanent muon flux from the Sun (2.2σ) was also detected in the daytime over a period
of 230 days upon daily 4-hour exposure. 相似文献
20.
This paper is concerned with certain connections between the ensemble of n×n unitary matrices – specifically the characteristic function of the random variable tr(U) – and combinatorics – specifically Ulam's problem concerning the distribution of the length of the longest increasing subsequence
in permutation groups – and the appearance of Painlevé functions in the answers to apparently unrelated questions. Among
the results is a representation in terms of a Painlevé V function for the characteristic function of tr(U) and (using recent results of Baik, Deift and Johansson) an expression in terms of a Painlevé II function for the limiting
distribution of the length of the longest increasing subsequence in the hyperoctahedral groups.
Received: 2 December 1998 / Accepted: 12 May 1999 相似文献