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191.
The solar climate ozone links (SOCOL) three-dimensional chemistry-climate model is used to estimate changes in the ozone and atmospheric dynamics over the 21st century. With this model, four numerical time-slice experiments were conducted for 1980, 2000, 2050, and 2100 conditions. Boundary conditions for sea-surface temperatures, sea-ice parameters, and concentrations of greenhouse and ozone-depleting gases were set following the IPCC A1B scenario and the WMO A1 scenario. From the model results, a statistically significant cooling of the model stratosphere was obtained to be 4–5 K for 2000–2050 and 3–5 K for 2050–2100. The temperature of the lower atmosphere increases by 2–3 K over the 21st century. Tropospheric heating significantly enhances the activity of planetary-scale waves at the tropopause. As a result, the Eliassen-Palm flux divergence considerable increases in the middle and upper stratosphere. The intensity of zonal circulation decreases and the meridional residual circulation increases, especially in the winter-spring period of each hemisphere. These dynamic changes, along with a decrease in the concentrations of ozone-depleting gases, result in a faster growth of O3 outside the tropics. For example, by 2050, the total ozone in the middle and high latitudes approaches its model level of 1980 and the ozone hole in Antarctica fills up. The superrecovery of the model ozone layer in the middle and high latitudes of both hemispheres occurs in 2100. The tropical ozone layer recovers far less slowly, reaching a 1980 level only by 2100.  相似文献   
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河北汉诺坝新生代玄武岩携带的石榴辉石岩为岩浆底侵于上地幔顶部40~45 km形成的堆晶岩,是壳-幔过渡带的典型样品。本文使用Solartron 1260阻抗分析仪,测量1.2 GPa和380~900 ℃下石榴辉石岩WD958的电阻率。样品电导率(σ)与温度的关系遵守Arrhenius方程: σ=σ0exp(-ΔH/kT),其中T是样品的绝对温度,k是Boltzmann常数,指前因子σ0为97.5 S/m,活化焓ΔH为1.27 eV。使用傅立叶红外光谱仪测定样品中单斜辉石的平均含水量为117×10-6 H2O,橄榄石无水,石榴子石的含水量因蚀变无法测定。使用Hashin-Shtrikman平均方法计算样品WD958的电导率,发现样品可看作由含水单斜辉石、无水石榴子石和无水橄榄石组成的高阻集合体,电导率同时受小极化子导电和质子导电的影响。如果原位的石榴辉石岩的矿物含水量保持平衡,其电导率将提高1个数量级,质子导电成为主控导电机制。石榴辉石岩在高温的壳-幔过渡带(~1 000℃)表现为高导层,而在正常地温梯度下,与尖晶石二辉橄榄岩的电导率近似,为高阻层。因此,在岩浆底侵作用下,电性上的壳-幔边界将随着温度和含水量的变化而改变。  相似文献   
195.
The orbits of the visual binaries ADS 8814 and ADS 8065 are determined for the first time. The orbits were calculated using the parameters of the apparent motion, based on position observations along short arcs obtained on the 26-inch refrector of the Pulkovo Observatory, supplemented with radial-velocity observations for the stellar components in both pairs obtained on the 1-m telescope of the Simeiz Section of the Crimean Astrophysical Observatory. All previous visual and photographic observations of these stars after 1832 were also taken into account. The orbit of ADS 8814 was refined using the differential-correction method. The orbital periods of these two stars are about 800 and 6000 years, respectively. The mass estimates derived for the known parallaxes from the Hipparcos catalog correspond to the spectral types of these stars. The polar vectors of the obtained orbits in Galactic coordinates are also given.  相似文献   
196.
We have studied the relative motions of the components of 25 visual binary and multiple stars for which only a modest number of observations of various types had accumulated due to their small relative component motions. A uniform series of photographic observations obtained over many years on the 26-inch refractor of the Pulkovo Observatory are used to calculate the parameters of the apparent relative positions and motions, which can be used for further kinematic and dynamical studies of these stars. A comparison of the relative and proper motions of the components indicates that they are physically bound. Optical components are identified in six systems??for the first time in the three systemsWDS00082+6217, ADS 830, and ADS 7361. The relative motions in ADS 861 and ADS 12925 suggest the presence of perturbing invisible companions, but this requires confirmation based on more accurate observations. The apparent motion parameters method yields a family of orbits with a minimum period of 26 000 yrs for the nearby wide visual binary Gliese 745, for which the parallax and relative radial velocity of the components are known.  相似文献   
197.
Comet C/1999 S4 (LINEAR) was exceptional in many respects. Its nucleus underwent multiple fragmentations culminating in the complete disruption around July 20, 2000. We present circular polarization measurements along the cuts through the coma and nucleus of the comet during three separate observing runs, in June 28-July 2, July 8-9, and July 21-22, 2000. The circular polarization was detected at a rather high level, up to 0.8%. The left-handed as well as right-handed polarization was observed over the coma with the left circularly polarized light systematically observed in the sunward part of the coma. During our observations the phase angle of the comet varied from 61 up to 122°, which allowed us to reveal variations of circular polarization with the phase angle. Correlation between the degree of circular polarization, visual magnitude, water production rate, and linear polarization of Comet C/1999 S4 (LINEAR) during its final fragmentation in July 2000 was found. The mechanisms that may produce circular polarization in comets and specifically in Comet C/1999 S4 (LINEAR) are discussed and some tentative interpretation is presented.  相似文献   
198.
SNAP, the SuperNova Acceleration Probe, is planned as a space-based telescope designed specifically to search for and monitor cosmological supernovae and weak lensing. In this paper we propose some other mission objectives which are of great importance in the fields of Galactic and extragalactic astronomy and which can be done as by-products with the same instrumentation and survey strategy as currently proposed for the main SNAP mission.  相似文献   
199.
We present the results of polarimetric and photometric observations of dynamically new comet C/2002 T7 (LINEAR) at phase angles from 6° to 26°. During the observations, the comet was at a distance of 2.7–1.3 AU from the Sun and 1.7–2.0 AU from the Earth. The aperture polarimetry was made with the 2.6-m Shain telescope and the 1.25-m AZT-11 telescope of the Crimean Astrophysical Observatory and with the 0.7-m telescope of the Astronomical Institute of the Kharkiv National University during the period from November 21, 2003, to February 21, 2004. The wideband UBVRI and WRC (λ7228/1142 Å) filters and the narrowband GC (λ5260/56 Å) filter were used. The photometric observations of the comet were carried out on February 21, 2004, with narrowband filters isolated the BC (λ4845/65 Å) and RC (λ6840/90 Å) continuum and the C2 emission (λ5140/90 Å). The phase-angle dependence of linear polarization of the comet has been obtained, and its parameters, such as the minimal polarization P min = ?1.63%, the phase angle of the minimal polarization αmin = 10.6°, the inversion angle αinv = 22.7°, and the slope of the phase curve at the inversion angle h = 0.24% per degree, were found. From the photometric observations, the following quantities have been obtained: the column density of molecules C2 in the line of sight logN (C2) = ?9.15 mol/cm2 and their production rate log Q (C2) = 27.11 mol/s, the spectral gradient of reflectivity for the dust S′(BC, RC) ≈ 3%/1000 Å, and the dust production parameter Afρ equal to 371 and 273 cm for the blue and red continuum ranges, respectively. According to these results, the physical parameters of comet C/2002 T7 are close to the average characteristics of typical dusty comets.  相似文献   
200.
The results of a complex study of the Upper Cretaceous carbonate section in the quarry of the cement plant of the town of Sengilei (Ul’yanovsk district) are presented. The Lower Paleocene cyclic opoka member is described. The formation conditions of the Upper Cretaceous cyclic and cryptocyclic, as well as Lower Paleocene cyclic, rocks are interpreted for the first time on the basis of lithological, petrographic, petromagnetic, geochemical, and paleoecological methods. The cyclicity was formed due to dilution cycles under climate fluctuation and eustatic variations, which were caused by eccentricity cycles of the Earth’s orbit. These cycles are identified in the cryptorhythmic lanceolata sequence of the Lower Maastrichtian rocks.  相似文献   
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