The report presents an analysis of a unique data set demonstrating the influence of geocryological processes on the 75-km Chara-China Railway track(northern Transbaikal region).The originality of these investigations ...The report presents an analysis of a unique data set demonstrating the influence of geocryological processes on the 75-km Chara-China Railway track(northern Transbaikal region).The originality of these investigations lies in the study of the influence of natural processes on the road in the absence of any repair works or protective and compensating measures for a long period of time(1998~2014).These conditions allowed assessment of the actual damage to the railroad.展开更多
The podiform chromitites occur in a well-preserved mantle sequence consisting of lherzolite-harzburgite with abundant lenses of olivine dunite. The podiform chromitite deposits are common as small and irregularly shap...The podiform chromitites occur in a well-preserved mantle sequence consisting of lherzolite-harzburgite with abundant lenses of olivine dunite. The podiform chromitite deposits are common as small and irregularly shaped masses in the Southeastern Desert (SED) of Egypt. The podiform chromitites exhibit a wide range of compositions from high Cr to high Al varieties. The Cr of chrome spinel ranges from 0.67 to 0.88 in olivine-dunite, quite similar to that of the high-Cr chromitite, whereas it is around 0.62 in lherzolite-harzburgite. Primary hydrous mineral inclusions, amphibole and phlogopite, in chrome spinel have been reported for the first time from the Pan-African Proterozoic podiform chromitites. On the other hand, petrographic and geochemical evidence suggests that podiform chromitites in the SED of Egypt were formed as a result of crystallization of mafic melts, probably of boninitic composition, the boninitic parental magmas were probably produced by a second stage of melting above a subduction zone. Three types of chromite ores can be distinguished within the SED of Egypt: (a) sulphide-poor podiform ores; (b) brecciated ores; and (c) sulphide-rich ores. Two textural types of inclusions in chromite are distinguished: (1) primary silicate inclusions generally have high Mg-number (>96), Cr and Ni, and are dominated by pargasitic amphibole, forsterite, diopside, enstatite and Na-phlogopite. A diversity of primary and secondary platinum group minerals (PGM) is described from the chromitites, including alloys, sulphides, sulpharsenides and arsenides of Ru, Os, Ir, Rh, Ni, Cu, Fe and Co; (2) in addition to primary PGM and hydrous silicates, the fluids are of low to moderate salinity, sodium-dominated aqueous solutions with complex gas contents. Variable amounts of water, hydrogen, hydrocarbons, carbon dioxides and nitrogen have been determined in inclusion-rich samples. The chondrite-normalized PGE patterns of lherzolite-harzburgite and olivine-dunite have negative Ir and Pt, and positive Pd and Au anomalies. Chromitites are homo-geneous in composition but texturally zoned on a large scale. They carry elevated IPGE, manifested in numerous, primary and secondary PGM phases.展开更多
The phenology of Chara vulgaris was studied.The specimens were collected four times from April 2004 to January 2005(one sampling per season).The water temperature,pH,dissolved oxygen,specific conductance,maximum width...The phenology of Chara vulgaris was studied.The specimens were collected four times from April 2004 to January 2005(one sampling per season).The water temperature,pH,dissolved oxygen,specific conductance,maximum width and maximum depth were monitored at every sampling time.Eighteen main morphological characteristics of the Chara vulgaris were also observed and measured under the microscope.The results showed that all the environmental factors had different seasonal patterns and some of the morphological characteristics had significant fluctuations,indicating differences in their seasonality.At the same time,some morphological characteristics were affected by the environmental parameters to some extent and the effect was primarily exhibited in its vegetative proportions;there was little effect on the sexual reproductive characteristics.Therefore,the relatively stable sexual reproductive characteristics can be used to identify the species.展开更多
The trajectory of Brownian motion is a classical example on fractal. Recently, M. A. Lpez-Quintela and his coworkers found that the fractal dimension of trajectory for Brownian motion increases as the number of steps ...The trajectory of Brownian motion is a classical example on fractal. Recently, M. A. Lpez-Quintela and his coworkers found that the fractal dimension of trajectory for Brownian motion increases as the number of steps increases, and pointed out that this展开更多
基金financial support of the Russian Fund of Basic Researches #1605-00200
文摘The report presents an analysis of a unique data set demonstrating the influence of geocryological processes on the 75-km Chara-China Railway track(northern Transbaikal region).The originality of these investigations lies in the study of the influence of natural processes on the road in the absence of any repair works or protective and compensating measures for a long period of time(1998~2014).These conditions allowed assessment of the actual damage to the railroad.
文摘The podiform chromitites occur in a well-preserved mantle sequence consisting of lherzolite-harzburgite with abundant lenses of olivine dunite. The podiform chromitite deposits are common as small and irregularly shaped masses in the Southeastern Desert (SED) of Egypt. The podiform chromitites exhibit a wide range of compositions from high Cr to high Al varieties. The Cr of chrome spinel ranges from 0.67 to 0.88 in olivine-dunite, quite similar to that of the high-Cr chromitite, whereas it is around 0.62 in lherzolite-harzburgite. Primary hydrous mineral inclusions, amphibole and phlogopite, in chrome spinel have been reported for the first time from the Pan-African Proterozoic podiform chromitites. On the other hand, petrographic and geochemical evidence suggests that podiform chromitites in the SED of Egypt were formed as a result of crystallization of mafic melts, probably of boninitic composition, the boninitic parental magmas were probably produced by a second stage of melting above a subduction zone. Three types of chromite ores can be distinguished within the SED of Egypt: (a) sulphide-poor podiform ores; (b) brecciated ores; and (c) sulphide-rich ores. Two textural types of inclusions in chromite are distinguished: (1) primary silicate inclusions generally have high Mg-number (>96), Cr and Ni, and are dominated by pargasitic amphibole, forsterite, diopside, enstatite and Na-phlogopite. A diversity of primary and secondary platinum group minerals (PGM) is described from the chromitites, including alloys, sulphides, sulpharsenides and arsenides of Ru, Os, Ir, Rh, Ni, Cu, Fe and Co; (2) in addition to primary PGM and hydrous silicates, the fluids are of low to moderate salinity, sodium-dominated aqueous solutions with complex gas contents. Variable amounts of water, hydrogen, hydrocarbons, carbon dioxides and nitrogen have been determined in inclusion-rich samples. The chondrite-normalized PGE patterns of lherzolite-harzburgite and olivine-dunite have negative Ir and Pt, and positive Pd and Au anomalies. Chromitites are homo-geneous in composition but texturally zoned on a large scale. They carry elevated IPGE, manifested in numerous, primary and secondary PGM phases.
基金This research was supported by grants from the National Natural Science Foundation of China(Grant Nos.30270119 and 30770162)the Agricultural Development Project of Shanxi Province,China(No.2007031042).
文摘The phenology of Chara vulgaris was studied.The specimens were collected four times from April 2004 to January 2005(one sampling per season).The water temperature,pH,dissolved oxygen,specific conductance,maximum width and maximum depth were monitored at every sampling time.Eighteen main morphological characteristics of the Chara vulgaris were also observed and measured under the microscope.The results showed that all the environmental factors had different seasonal patterns and some of the morphological characteristics had significant fluctuations,indicating differences in their seasonality.At the same time,some morphological characteristics were affected by the environmental parameters to some extent and the effect was primarily exhibited in its vegetative proportions;there was little effect on the sexual reproductive characteristics.Therefore,the relatively stable sexual reproductive characteristics can be used to identify the species.
基金Project supported by the National Natural Science Foundation of China.
文摘The trajectory of Brownian motion is a classical example on fractal. Recently, M. A. Lpez-Quintela and his coworkers found that the fractal dimension of trajectory for Brownian motion increases as the number of steps increases, and pointed out that this
