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351.
In the Guide Star Catalog (GSC) 223 new trapezia have been found. A new, more complete list of trapezia, including 637 objects,
has been compiled on the basis of the GSC and the Washington Double Star Catalog.
Translated from Astrofizika, Vol. 42, No. 4, pp. 571–578, October–December, 1999. 相似文献
352.
R. Sh. Natsvlishvili 《Astrophysics》1999,42(1):117-118
Flare periodicity has been found in the flare star Pleiades No. 484. The period of its flare activity is determined from an
analysis of the flares’time distribution.
Translated from Astrofizika, Vol. 42, No. 1, pp. 159–160, January–March, 1999. 相似文献
353.
Algorithm for recognizing Pc3 geomagnetic pulsations in 1-s data from INTERMAGNET equatorial observatories 总被引:1,自引:0,他引:1
N. R. Zelinskiy N. G. Kleimenova O. V. Kozyreva S. M. Agayan Sh. R. Bogoutdinov A. A. Soloviev 《Izvestiya Physics of the Solid Earth》2014,50(2):240-248
The methods are suggested for analyzing the data of three-component geomagnetic observations in order to automatically recognize time anomalies-pulsations in the geomagnetic field. These methods include preliminary bandpass filtering of the data, calculating the eigenvalues of the covariance matrix of magnetic components in a moving time window, computing the generalized variance of the eigenvalues (generalization is understood as raising to a power that is distinct from the traditional power of 2), averaging the variance, and identifying the time intervals marked by the presence of pulsations by the criterion of the averaged variance of eigenvalues to exceed a certain threshold specified by the fuzzy-logic methods. 相似文献
354.
为揭示微囊藻群体形成机理,为有效防治水华暴发提供依据,以三峡库区铜绿微囊藻(Microcystis aeruginosa)为研究对象,研究N、P浓度,Ca~(2+)浓度,光强,温度对铜绿微囊藻生长、胞外多糖(EPS)合成和群体微囊藻形成的影响,并对比分析了单细胞和群体微囊藻的形态特征.研究发现当N≤100 mg/L、P≤5 mg/L时,铜绿微囊藻生物量和EPS合成量随着N、P浓度增加而增加;适宜浓度的Ca~(2+)(65 mg/L)有利于藻生长,EPS产量随着Ca~(2+)浓度增加而降低,过高浓度的Ca~(2+)在刺激微囊藻细胞分泌EPS的同时可能会促进其溶解,Ca~(2+)和EPS均对微囊藻群体形成起桥架粘结作用;光照和温度对EPS合成有一定促进作用,且其促进效果均高于N、P和Ca~(2+)作用,20℃是同时满足微囊藻生长及EPS合成的最有利条件.群体细胞比单细胞周围的胶质鞘更加明显和清晰,多糖胶鞘表面有许多Ca~(2+)晶体,从微观角度可以确定Ca~(2+)在EPS合成及群体形成中起着重要作用. 相似文献
355.
P. N. Makkaveev P. A. Stunzhas Z. G. Mel’nikova P. V. Khlebopashev Sh. Kh. Yakubov 《Oceanology》2010,50(5):688-697
Hydrochemical studies of the Kara Sea were included into the program of the integrated expedition during cruise 54 of the
R/V Akademik Mstislav Keldysh (September 9–30, 2007). In several sea areas quite different in their weather conditions, a large set of hydrochemical analyses
was carried out, including the determination of the primary nutrients (silicon and different forms of nitrogen and phosphorus),
the dissolved oxygen content, and the total alkalinity and pH values. The report presents the hydrochemical conditions in
the southwestern part of the Kara Sea and the most striking results from the authors’ viewpoint. The data were compared to
those of the integrated oceanographic expedition of cruise 49 of the R/V Dmitry Mendeleev in 1993. 相似文献
356.
L.?S.?Ugol’kovaEmail author B.?P.?Artamonov E.?V.?Shimanovskaya V.?V.?Bruevich O.?Burkhonov Sh.?A.?Egamberdiev N.?V.?Metlova 《Astronomy Letters》2017,43(4):233-240
We present the results of our multicolor UBV RI observations of NGC 7469, a type 1 Seyfert galaxy (SyG 1), in 2008–2014 at the Maidanak Observatory. Analysis of the long-term variability of NGC 7469 for two observing periods, 1990–2007 and 2008–2014, has shown the existence of yet another activity cycle of the slow component in 2009–2014 with an activity maximum in 2011–2012. We have studied the slow variability component in 2009–2014 and constructed the color–color (U ? B), (B ? V) diagrams for the variability maxima and minima of NGC 7469 in various apertures and for the blackbody gas radiation modeling the accretion disk radiation. It can be seen from the color–color diagram that the color of the nuclear part of NGC 7469 becomes bluer at maximum brightness, suggesting a higher temperature of the accretion disk. We have analyzed the X-ray variability of NGC 7469 in 2008 and 2009 in comparison with the activity minimum in 2003. The optical–X ray correlation coefficient in 2008 is close to 0.5. The weak correlation is explained by the influence of an SN 1a explosion in the circumnuclear part of NGC 7469, which manifests itself in the optical band but does not change the pattern of X-ray variability. Comparison of the variability data for 2009 shows an optical–X ray (U band–7–10 keV) correlation with a correlation coefficient of about 0.93. The correlation coefficient and the lag depend on the wavelength in the optical and X-ray bands. The lag between the X-ray and optical fluxes in 2009 is observed to a lesser extent in 2003. 相似文献
357.
XIAO QiBin ZHAO GuoZe WANG JiJun ZHAN Yan CHEN XiaoBin TANG Ji CAI JunTao WAN ZhanSheng WANG LiFeng MA Wei & ZHANG JiHong Institute of Geology China Earthquake Administration Beijing China Earthquake Administration of Sh ong Province Jinan 《中国科学D辑(英文版)》2009,52(3):420-430
Because of the discovery of ultrahigh pressure metamorphic (UHPM) belt beneath the Sulu (Jiangsu Province-Shandong Province)
orogen, this area has become a focused subject of current geoscience, as it has a close relationship with the evolution of
the orogen and the neighboring North China craton. Probing the deep structure beneath this area would be of great significance
for the geological interpretation of this issue. In this study, we make an analysis of magnetotelluric (MT) data along a profile
across the Sulu orogen to provide evidence of deep structure below this region. The profile begins in west from the North
China block, extending in S129°E, across the Tan-Lu fault, Sulu UHPM zone, and Sulu high pressure metamorphic (HPM) zone,
and terminates in the Yangtze block in east. We use the nonlinear conjugate gradient method and TE-TM combined mode to perform
inversion and interpretation of the MT data, and obtain an electrical structure image above depth of 150 km along the profile.
It shows that the structure can be divided into seven sections in lateral direction, between which the electric boundaries
coincide well with the major faults, such as the Tan-Lu, Haizhou-Siyang, and Jiashan-Xiangshui faults. In vertical direction
the electrical structure can be subdivided into six layers of different resistivities. It is noted that there exist high-conductivity
areas in crust below the North China block and Yangtze block, while such a feature is not present beneath the Sulu orogen,
which is very different from the Dabie orogen. It is also observed that a fairly continuous zone of relatively low-resistivity
exists at depths of 50–90 km of the electrical structure image, which is presumably a weak zone in the uppermost mantle. Just
below this low-resistivity zone are the relatively high- resistivity layer of the North China block, relatively low-resistivity
layer of the Sulu orogen, and relatively high-resistivity layer of the Yangtze block, all in the shallow upper mantle, respectively.
From the whole 2D electrical structure image, there is no abnormally low-resistivity layer in the shallow upper mantle beneath
the Sulu orogen and neighboring areas, indicating that no hot asthenoshperic material associated with lithospheric thinning
exists at present.
Supported by National Natural Science Foundation of China (Grant No. 40534023) and Director Foundation of Institute of Geology,
China Earthquake Administration (Grant No. DF-IGCEA-0608-2-16) 相似文献
358.
M. Saeedi Sh. Daneshvar A. R. Karbassi 《International Journal of Environmental Science and Technology》2004,1(2):135-140
Riverine sediments and suspended matters have been subjected to several bench scale tests for the evaluation of adsorption potential of heavy metals. For this purpose water, sediment and suspended particulate matters of Tadjan River (southern part of the Caspian Sea) were collected. In the vicinity of the river many polluting sources were recognized; for instance, pulp and paper mill, dairy factory and municipal sewage that can introduce various amounts of heavy metals into the river water. Bottom sediments and suspended particulate matters have been individually subjected to adsorption tests. The results of analysis showed that riverine bottom sediments have greater potential for adsorbing heavy metals than suspended matters. However the trend of adsorption in both sediments and suspended matters are similar. Maximum adsorption capacity of heavy metals (in terms of mg of metal per kg of sediments and suspended matters) by sediments and suspended matters are as: Sediments: Cu (2200)> Mn (2000)> Ni (1400)> Zn (320) Suspended matters: Cu (2100)> Ni (1500)> Mn (1200)> Zn (310) Further, results revealed that increasing concentration of metals would cause desorbing Cadmium from both sediments and suspended matters. 相似文献
359.
Ahmed Mohammed A. Hegab Omar A. Awadalla Ahmed Sh. Farag Ali E. Hassan Saad 《Natural Resources Research》2019,28(4):1547-1573
Natural Resources Research - A multiple forward 1D modeling approach on four wells in the Abu Rudeis-Sidri oil field has been performed in accordance with the plate tectonics and crustal... 相似文献
360.
Kuleshevich L. V. Filippov M. M. Goltsin N. A. Krymsky R. Sh. Lokhov K. I. 《Lithology and Mineral Resources》2019,54(2):145-158
Lithology and Mineral Resources - The Maksovo shungite-bearing metasapropelite (maksovite) deposit is located in the eastern part of the Onega Basin that was initiated and formed in the... 相似文献