scholarly journals Intergranular trace elements in mantle xenoliths from Russian Far East: Example for mantle metasomatism by hydrous melt

Island Arc ◽  
2009 ◽  
Vol 18 (1) ◽  
pp. 225-241 ◽  
Author(s):  
Junji Yamamoto ◽  
Shun'ichi Nakai ◽  
Koshi Nishimura ◽  
Ichiro Kaneoka ◽  
Hiroyuki Kagi ◽  
...  
Author(s):  
Xinran Xu ◽  
Yanjie Tang ◽  
Jifeng Ying ◽  
Xinmiao Zhao ◽  
Yan Xiao

We present mineralogical and geochemical compositions of mantle xenoliths from two Cenozoic basalt localities of the northeastern North China Craton. These xenoliths include lherzolite, harzburgite, and websterite. They are generally fertile in major elements and different from the typical cratonic lithosphere, which is consistent with previous hypotheses regarding craton destruction. The ratios of 87Sr/86Sr and (La/Yb)N of clinopyroxenes (Cpx) in one lherzolite are relatively low in the core but high in the rim. The center of the Cpx grain has a high U concentration. Changes in trace elements and Sr isotopes indicate that later stage high 87Sr/86Sr melt metasomatism superimposed on the early hydrous melt/fluid. The Cpxs in some xenoliths are low in Ti/Eu but high in Ca/Al and light rare earth elements, which indicates carbonate melt metasomatism. 87Sr/86Sr is increased in the core and decreased in the rim of most Cpx grains, which reflects the superposition of two-stage metasomatism. The early agent should be high in 87Sr/86Sr, and the recent agent should be low in 87Sr/86Sr. The Cpxs in olivine websterite are low in 87Sr/86Sr (0.70220−0.70320), which reflects the recent metasomatism of asthenosphere-derived melt. Collectively, these observations reflect a three-stage modification of the lithospheric mantle. First-stage hydrous melt/fluid could come from the dehydration of young subducted plates. Second-stage melt/fluid of high 87Sr/86Sr could derive from the partial melting of the subducted altered oceanic crust, and the recent melt/fluid of low 87Sr/86Sr should be from the asthenosphere.


2019 ◽  
pp. 27-33
Author(s):  
Aleksei K. Solovyov ◽  
Bi Guofu

The term “window” in architecture usually stands for an opening in a wall or roof for penetration of natural light, sunrays and fresh air in premises. Recently, the requirement of contact with environment is added to this condition. It is especially relevant for residential buildings where rooms are considered residential if they have windows. The energy consumption of a building depends on sizes, form and location of windows. In winter, windows cause huge heat losses, in summer, on the other hand, large heat enters a building via the windows and is required to be removed by means of air conditioning. Moreover, windows are used for penetration of natural light in premises, which assists in saving of large amounts of power for artificial illumination. This article discusses partial solving the problem of the energy efficiency of residential buildings by determining the most efficient area of windows in terms of energy spending for compensation of heat losses via windows in winter, elimination of heat penetration through them in summer and energy losses for artificial lighting throughout the year. The analysis of the results of calculation of power consumption for residential premises in conditions of monsoon climate of the Russian Far East and Northern areas of China (PRC) is provided.


2020 ◽  
Vol 13 (2) ◽  
pp. 216-242
Author(s):  
V.A. Yakimova ◽  
A.A. Orekhova

Subject. The article addresses the tax liabilities of taxpayers registered in the subjects of the Far Eastern Federal District, which should be paid to the consolidated budget of the Russian Federation, as well as the factors of the said debt growth. Objectives. Our aim is to assess the level of tax debt of regions of the Russian Far East and identify the correlation between the factors and the amount of tax debt. Methods. The study rests on methods of analysis, generalization, grouping, systematization, and the correlation and regression analysis. Results. We analyzed the level of tax debt for the entire Far Eastern Federal District and by region, identified factors affecting the growth of tax debt therein. The paper assesses the structure of tax debt by type of taxes and activity of debtors. The unveiled factors may help control changes in the size of tax debt in the Russian Far East and develop effective measures to improve the debt collection. Conclusions. The study shows that there is an increase in the tax debt in the regions of the Russian Far East, in the VAT in particular. The factor analysis revealed that the volume of sales of wholesale enterprises, investment in fixed capital, the consumer price index have the largest impact on the amount of tax debt.


2018 ◽  
Vol 65 ◽  
pp. 89-102
Author(s):  
Z.V. Kozhevnikova ◽  
◽  
A.E. Kozhevnikov ◽  

2018 ◽  
Vol 360 ◽  
pp. 25-28 ◽  
Author(s):  
A.V. Kuprin ◽  
◽  
N.A. Kolyada ◽  
D.G. Kasatkin ◽  
◽  
...  

2020 ◽  
Vol 68 ◽  
pp. 29-64
Author(s):  
N.S. Probatova ◽  

The paper summarizes information on chromosome numbers (CNs) of the Grass species (Poaceae) in the flora of Russian Federation, obtained on the original material, most part - from the Russian Far East (RFE). In some species the CNs are known in Russia or in the world only from RFE, in some – from one locality or few, or from one subregion of RFE. The grass species in RFE often occur in mountain regions and near seacoasts; some species are endemics, some were studied near the limits of their geographical distribution areas. The diversity of CNs, the special features of the CNs distribution in some grass groups are discussed. The alien species are abundant in RFE, and their CNs are also involved in the study. For karyologically polymorphous species further studies are needed.


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