With a view to obtaining an exact closed form solution to the Schroedinger equation for a variety of hypercentral potentials, we investigate further application of an ansatz. This method is good enough for many kinds ...With a view to obtaining an exact closed form solution to the Schroedinger equation for a variety of hypercentral potentials, we investigate further application of an ansatz. This method is good enough for many kinds of potentials, but in this article it applies to a type of the hypercentral singular potentials V（x） = ax^2 ＋ bx^-4＋ cx^-6 and exponential hypercentral Morse potential U （x） = Uo （ e^-2ax - 2 e^-ax） for three interacting particles. The Morse potential is used for diatomic molecule while this method will be successfully used for many atomic molecules. The three-body potentials are more easily introduced and treated within the hyperspherical harmonic formalism. The internal particle motion is usually described by means of Jacobi relative coordinates p, A, and R, in terms of three particle positions r1, r2, and r3. We discuss some results obtained by using harmonic and anharmonic oscillators, however the hypercentral potential can be easily generalized in order to allow a systematic anaiysis, which admits an exact solution of the wave equation. This method is also applied to some other types of three-body, four-body, ..., interacting potentials.展开更多
The paper is based on author＇s observations during long geological field investigations in the Nepal Himalayas and various other international researches pertaining to natural hazards, global warming and climate chan...The paper is based on author＇s observations during long geological field investigations in the Nepal Himalayas and various other international researches pertaining to natural hazards, global warming and climate change. High mountains all over the world including Nepal Himalaya are threatened by global warming. In addition, Nepal lies at heart of Himalayan orogenic belt and is prone to both geological and hydro-meteorological hazard. Tremendous geographic diversity from high mountains to fiat plains presents specific hazards like earthquakes, avalanche, glacial lake outburst flood, debris flow, floods, landslides, thunderstorm, fire, cold and hot waves, etc. These natural hazards combined with anthropogenic hazards aggravate and degrade the fragile eco-systems, put human lives at risk, and cause immense economic losses. In last 25 years, it has attributed to an average annual loss of about 850 lives, damage of infrastructures and properties equivalent to about 6% of the annual development expenditure. GHGs （Green House Gases） are the chief sources of global warming and climate change. In Nepal, these are marked by an average of 0.06℃ per year rise in temperature, fast snow melting, retreating glaciers, vertical shift in snowline, decrease in amount of snowfall, appearance of new glacial lakes and increase in their size and volume. There is a need of strong commitment of international community to work together to reduce GHGs, CFC （Chlorofluorocarbon）, and international and regional cooperation to face the present challenges of global warming and climate change. Government of Nepal already prepared the National Strategy for Disaster Risk Management for building a resilient nation emphasizing on assessment, identification, and monitoring of disaster risk and enhancing early warning system.展开更多
The geochemical characteristics of two sections—the Permian–Triassic boundary(PTB) Guryul Ravine section, Kashmir Valley, Jammu and Kashmir,India; and the Attargoo section, Spiti Valley, Himachal Pradesh, India—hav...The geochemical characteristics of two sections—the Permian–Triassic boundary(PTB) Guryul Ravine section, Kashmir Valley, Jammu and Kashmir,India; and the Attargoo section, Spiti Valley, Himachal Pradesh, India—have been studied in the context of provenance, paleo-weathering, and plate tectonic setting.These sections represent the siliciclastic sedimentary sequence from the Tethys Himalaya. The PTB siliciclastic sedimentary sequence in these regions primarily consists of sandstones and shales with variable thickness. Present studied sandstones and shales of both sections had chemical index of alteration values between 65 and 74; such values reveal low-to-moderate degree of chemical weathering. The chemical index of weathering in studied samples ranged from 71 to 94, suggesting a minor K-metasomatism effect on these samples. Plagioclase index of alteration in studied sections ranged from 68 to 92, indicating a moderate degree of weathering of plagioclase feldspars. The provenance discriminant function diagram suggests that the detritus involved in the formation of present studied siliciclastic sedimentary rocks fall in quartzose sedimentary and felsic igneous provenances. These sediments were deposited in a passive continental margin plate tectonic setting according to their location on a Si_2 O versus K_2O/Na_2 O tectonic setting diagram.展开更多
Study of the characteristics of the crustal magnetic anomaly in the Qinghai-Tibet Plateau and the adjacent areas helps better understand the lithospheric structure and evolution, as well as the regional geodynamic pro...Study of the characteristics of the crustal magnetic anomaly in the Qinghai-Tibet Plateau and the adjacent areas helps better understand the lithospheric structure and evolution, as well as the regional geodynamic processes. Here we analyze the distri- bution laws of the crustal magnetic anomaly and its vertical gradient, the decay characteristics of the anomaly, the contribu- tions from different wavelength bands to the anomaly, and the relationship between the anomaly and the crustal regional tec- tonics in the plateau and nearby, based on a new and higher degree geomagnetic model NGDC-EMM-720-V3 constructed from the surface, aeromagnetic, marine and satellite survey data. The results reveal that the positive and negative anomalies in the Qinghai-Tibet Plateau are weak, while those of the surrounding areas are strong. The boundary agrees well with the border of the plateau regional tectonics. The anomaly is nearly east-west in the central and western plateau, arc-shaped in the south- western and eastern, and nearly north-south in the southeastern, consistent with the tectonic trends. There are strong negative anomaly loci in the east and west syntaxis, whereas no significant differences exist among the Cenozoic blocks in the plateau interior. No direct correspondence exists between the anomaly and the crustal depth. On the background of a weak magnetic anomaly in the plateau, relatively stronger short wavelength fields from the shallower crust are overlapped in the Lhasa, Qilian, Qaidam, and Sichuan-Yunnan rhombic blocks. A strong negative anomaly in the east-west direction is distributed along the Himalayas, mainly caused by the middle and long wavelength bands in the deep and central crust. The magnetic structural lay- ers are stable in the Sichuan and Tarim basins. The anomalies at different altitudes over the southern plateau vary strongly, showing a drastic variation in the magnetic structure from the deep crust to the shallow crust.展开更多
文摘With a view to obtaining an exact closed form solution to the Schroedinger equation for a variety of hypercentral potentials, we investigate further application of an ansatz. This method is good enough for many kinds of potentials, but in this article it applies to a type of the hypercentral singular potentials V（x） = ax^2 ＋ bx^-4＋ cx^-6 and exponential hypercentral Morse potential U （x） = Uo （ e^-2ax - 2 e^-ax） for three interacting particles. The Morse potential is used for diatomic molecule while this method will be successfully used for many atomic molecules. The three-body potentials are more easily introduced and treated within the hyperspherical harmonic formalism. The internal particle motion is usually described by means of Jacobi relative coordinates p, A, and R, in terms of three particle positions r1, r2, and r3. We discuss some results obtained by using harmonic and anharmonic oscillators, however the hypercentral potential can be easily generalized in order to allow a systematic anaiysis, which admits an exact solution of the wave equation. This method is also applied to some other types of three-body, four-body, ..., interacting potentials.
文摘The paper is based on author＇s observations during long geological field investigations in the Nepal Himalayas and various other international researches pertaining to natural hazards, global warming and climate change. High mountains all over the world including Nepal Himalaya are threatened by global warming. In addition, Nepal lies at heart of Himalayan orogenic belt and is prone to both geological and hydro-meteorological hazard. Tremendous geographic diversity from high mountains to fiat plains presents specific hazards like earthquakes, avalanche, glacial lake outburst flood, debris flow, floods, landslides, thunderstorm, fire, cold and hot waves, etc. These natural hazards combined with anthropogenic hazards aggravate and degrade the fragile eco-systems, put human lives at risk, and cause immense economic losses. In last 25 years, it has attributed to an average annual loss of about 850 lives, damage of infrastructures and properties equivalent to about 6% of the annual development expenditure. GHGs （Green House Gases） are the chief sources of global warming and climate change. In Nepal, these are marked by an average of 0.06℃ per year rise in temperature, fast snow melting, retreating glaciers, vertical shift in snowline, decrease in amount of snowfall, appearance of new glacial lakes and increase in their size and volume. There is a need of strong commitment of international community to work together to reduce GHGs, CFC （Chlorofluorocarbon）, and international and regional cooperation to face the present challenges of global warming and climate change. Government of Nepal already prepared the National Strategy for Disaster Risk Management for building a resilient nation emphasizing on assessment, identification, and monitoring of disaster risk and enhancing early warning system.
文摘The geochemical characteristics of two sections—the Permian–Triassic boundary(PTB) Guryul Ravine section, Kashmir Valley, Jammu and Kashmir,India; and the Attargoo section, Spiti Valley, Himachal Pradesh, India—have been studied in the context of provenance, paleo-weathering, and plate tectonic setting.These sections represent the siliciclastic sedimentary sequence from the Tethys Himalaya. The PTB siliciclastic sedimentary sequence in these regions primarily consists of sandstones and shales with variable thickness. Present studied sandstones and shales of both sections had chemical index of alteration values between 65 and 74; such values reveal low-to-moderate degree of chemical weathering. The chemical index of weathering in studied samples ranged from 71 to 94, suggesting a minor K-metasomatism effect on these samples. Plagioclase index of alteration in studied sections ranged from 68 to 92, indicating a moderate degree of weathering of plagioclase feldspars. The provenance discriminant function diagram suggests that the detritus involved in the formation of present studied siliciclastic sedimentary rocks fall in quartzose sedimentary and felsic igneous provenances. These sediments were deposited in a passive continental margin plate tectonic setting according to their location on a Si_2 O versus K_2O/Na_2 O tectonic setting diagram.
基金sponsored by National Natural Science Foundation of China (Grant Nos. 40464001 and 40864002)
文摘Study of the characteristics of the crustal magnetic anomaly in the Qinghai-Tibet Plateau and the adjacent areas helps better understand the lithospheric structure and evolution, as well as the regional geodynamic processes. Here we analyze the distri- bution laws of the crustal magnetic anomaly and its vertical gradient, the decay characteristics of the anomaly, the contribu- tions from different wavelength bands to the anomaly, and the relationship between the anomaly and the crustal regional tec- tonics in the plateau and nearby, based on a new and higher degree geomagnetic model NGDC-EMM-720-V3 constructed from the surface, aeromagnetic, marine and satellite survey data. The results reveal that the positive and negative anomalies in the Qinghai-Tibet Plateau are weak, while those of the surrounding areas are strong. The boundary agrees well with the border of the plateau regional tectonics. The anomaly is nearly east-west in the central and western plateau, arc-shaped in the south- western and eastern, and nearly north-south in the southeastern, consistent with the tectonic trends. There are strong negative anomaly loci in the east and west syntaxis, whereas no significant differences exist among the Cenozoic blocks in the plateau interior. No direct correspondence exists between the anomaly and the crustal depth. On the background of a weak magnetic anomaly in the plateau, relatively stronger short wavelength fields from the shallower crust are overlapped in the Lhasa, Qilian, Qaidam, and Sichuan-Yunnan rhombic blocks. A strong negative anomaly in the east-west direction is distributed along the Himalayas, mainly caused by the middle and long wavelength bands in the deep and central crust. The magnetic structural lay- ers are stable in the Sichuan and Tarim basins. The anomalies at different altitudes over the southern plateau vary strongly, showing a drastic variation in the magnetic structure from the deep crust to the shallow crust.
