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31.
UBVR
c
I
c observations of SN 2002ap during February, October, and November 2002 at the Crimean Astrophysical Observatory are reported. An examination of our photometric data, along with published data, shows that over a period of about a year from the day the SN 2002ap supernova burst, the light curve passed through three developmental stages: a sharp rise, followed by a stage of rapid exponential decrease, and then a slower fading. Based on the shape of the light curve, this supernova is of type SN I, but according to the variation in its color indices, it more likely belongs to the SN Ic supernovae. In the premaximum stage, the energy distribution from 3000 to 6000 resembles the emission from a star of spectral class F5V. In the second stage of the light curve evolution, when the brightness falls off rapidly, the changes in the color indices are associated with a change in the radiation temperature indicative of rapid cooling of the ejected material. Taking the effective radiation temperature in the premaximum stage to be T
eff 6500 K, we estimate the expansion velocity of the quasiphotosphere to be about 9700 km/s. 相似文献
32.
B. Růžek P. Hrubcová M. Novotný A. Špičák O. Karousová 《Studia Geophysica et Geodaetica》2007,51(1):141-164
A series of kinematic inversions based on robust non-linear optimization approach were performed using travel time data from
a series of seismic refraction experiments: CELEBRATION 2000, ALP 2002 and SUDETES 2003. These experiments were performed
in Central Europe from 2000 to 2003. Data from 8 profiles (CEL09, CEL10, Alp01, S01, S02, S03, S04 and S05) were processed
in this study. The goal of this work was to find seismic velocity models yielding travel times consistent with observed data.
Optimum 2D inhomogeneous isotropic P-wave velocity models were computed. We have developed and used a specialized two-step
inverse procedure. In the first “parametric” step, the velocity model contains interfaces whose shapes are defined by a number
of parameters. The velocity along each interface is supposed to be constant but may be different along the upper and lower
side of the interface. Linear vertical interpolation is used for points in between interfaces. All parameters are searched
for using robust non-linear optimization (Differential Evolution algorithm). Rays are continuously traced by the bending technique.
In the second “tomographic” step, small-scale velocity perturbations are introduced in a dense grid covering the currently
obtained velocity model. Rays are fixed in this step. Final velocity models yield travel time residuals comparable to typical
picking errors (RMS ∼ 0.1 s).
As a result, depth-velocity cross-sections of P waves along all processed profiles are obtained. The depth range of the models
is 35–50 km, the velocity varies in the range 3.5–8.2 km/s. Lowest velocities are detected in near-surface depth sections
crossing sedimentary formations. The middle crust is generally more homogeneous and has typical P wave velocity around 6 km/s.
Surprisingly the lower crust is less homogeneous and the computed velocity is in the range 6.5–7.5 km/s. The MOHO is detected
in the depth ≈30–45 km. 相似文献
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35.
2002年塔里木河流域四条源流区间耗水分析 总被引：6，自引：16，他引：6
2002年塔里木河四条源流出山口天然径流量273.9×108m3, 比多年平均值多46.9×108m3, 偏多20.7%, 属丰水年.其中发源于天山山脉的阿克苏河和开都河-孔雀河径流增幅大, 水量充沛, 属丰水年, 而发源于昆仑山脉的叶尔羌河和和田河径流量保持多年均值年.2002年度, 四条源流区总耗水量219.1×108m3, 占出山口天然径流量的80.0%.其中阿克苏河流域总耗水量为65.90×108m3, 占出山口天然径流量的60%; 叶尔羌河流域耗水量61.92×108m3, 年内无水量进入塔里木河干流; 和田河流域耗水量36.45×108m3, 占出山口天然径流量的80.9%.开-孔河流域内耗水54.76×108m3, 占出山口天然径流量的95.9%. 相似文献
36.
分析DI2002测距仪在川西高原虾拉沱基线场地对基线AB边和AC边进行短距测量实验所得数据,检验DI2002测距仪在气候独特的高原环境中是否满足距离测量限差精度要求,并将其测量结果与同期基线测量数据资料进行比较.得出DI2002测距仪能适用于气候瞬息多变的川西高原. 相似文献
37.
中国省区间产业内贸易与产业结构同构分析 总被引：5，自引：1，他引：4
基于2002 年中国省区间投入产出模型,从产业内贸易角度重新审视产业结构同构问题。研究表明,中国制造业存在着一定的产业结构同构现象,但空间上不均衡。华东沿海地区存在着大类层面的产业内贸易和中小分类的产业间贸易,使得江浙沪之间形成了密切的产业关联,因此不能仅以产业结构同构程度来判断产业地域分工和区域经济一体化进程。基于大类产业层次的产业结构同构分析可能会高估产业结构同构程度,在中小类产业层次判断区域间产业结构同构会得到更符合现实的结论。产业内贸易已成为中国省区间贸易联系的重要形式。各省区制造业在产业链中的分工不同、相似的需求偏好和产品差异化竞争是促进产业内贸易的重要因素。产业内贸易既可以在产业结构相似的省份之间发生,也存在于产业结构差异明显的省份之间。如果区域之间存在着活跃的产业内贸易,产业结构同构不一定阻碍区域经济一体化。 相似文献
38.
D. K. Sahu G. C. Anupama T. P. Prabhu 《Monthly notices of the Royal Astronomical Society》2006,366(2):682-688
Optical UBVRI photometry of the type Ia supernova (SN Ia) SN 2002hu covering the period from −2 to +73 d since B maximum is presented. The supernova reached at maximum brightness in B on JD 245 2591.78 ± 0.5 with an apparent magnitude of 16.83 ± 0.02 mag and a relatively blue colour ( B − V ) =−0.08 ± 0.04 mag . The luminosity decline rate of Δ m 15 ( B ) = 1.00 ± 0.05 indicates an absolute B magnitude at maximum of M max B =−19.38 ± 0.3 . The estimated absolute B magnitude, together with the photometric evolution, indicate SN 2002hu was slightly overluminous compared to the average SNe Ia. The distance modulus to the parent galaxy is estimated to be μ= 36.04 ± 0.20 . 相似文献
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PRIMARY ANALYSIS ON GROUNDWATER, SOIL MOISTURE AND SALINITY IN FUKANG OASIS OF SOUTHERN JUNGGAR BASIN 总被引：1，自引：1，他引：0
GUFeng-xue ZHANGyuan-dong CHUYu SHIQing-dong PANXiao-ling 《中国地理科学(英文版)》2002,12(4):333-338
１INTRODUCTIONSoilandlandformarethemoreimportantenviron－mentalfactorsaffectingthedistributionofvegetationinabasinwhenthemeteorologicconditionissimilaronalargescale，especiallyspatialandtemporalvariationsofthesoilmoistureandsaltcontent．Inaridareasthesoil… 相似文献