The uplift of the Ailao Shan-Diancang Shan （ASDS） along the Ailao Shan-Red River （ASRR） shear zone is an important geological event in the southeastern margin of Qinghai-Tibet Plateau tectonic domain in the Late C...The uplift of the Ailao Shan-Diancang Shan （ASDS） along the Ailao Shan-Red River （ASRR） shear zone is an important geological event in the southeastern margin of Qinghai-Tibet Plateau tectonic domain in the Late Cenozoic, and it preserves important information on the structures, exhumationai history and tectonic evolution of the ASRR shear zone. The uplift structural mode and uplift timing of the ASDS is currently an important scientific topic for understanding the ASDS formation and late stage movements and evolution of the ASRR shear zone. The formation of the ASDS has been widely considered to be the consequence of the strike-slip movements of the ASRR shear zone. However, the shaping of geomorphic units is generally direct results of the latest tectonic activities. In this study, we investigated the timing and uplift structural mechanism of the ASDS and provided the following lines of supportive evidence. Firstly, the primary tectonic foliation of the ASDS shows significant characteristic variations, with steeply dipping tectonic foliation developed on the east side of the ASDS and the relatively horizontal foliation on the west side. Secondly, from northeast to southwest direction, the deformation and metamorphism gradually weakened and this zone can be further divided into three different metamorphic degree belts. Thirdly, the contact relationship between the ASDS and the Chuxiong basin-Erhai lake is a normal fault contact which can be found on the east side of the ASDS. 40^Ar/^39 Argeochronology suggests that the Diancang Shan had experienced a fast cooling event during 3-4 Ma. The apatite fission track testing method gives the age of 6.6-10.7 Ma in the Diancang Shan and 4.6-8.4 Ma in the Ailao Shan, respectively. Therefore the uplift of the ASDS can be explained by tilted block mode in which the east side was uplifted much higher than the west side, and it is not main reason of the shearing movements of the ASRR shear zone. The most recent uplift stages of the ASDS happened in the Pliocene （3-4 Ma） and Late Miocene （6-10 Ma）.展开更多
The 3s–np photoionization processes of the ground state 2P1/2 and the metastable state 2P3/2 of Ar5＋ are investigated using our recently developed relativistic R-matrix code, where the interactions between the bound...The 3s–np photoionization processes of the ground state 2P1/2 and the metastable state 2P3/2 of Ar5＋ are investigated using our recently developed relativistic R-matrix code, where the interactions between the bound states and the continuum states are included. Both resonance positions and the oscillator strengths are in much better agreement with the absolute experimental measurements by Wang et al.[Wang J C, Lu M, Esteves D, Habibi M, Alna’washi G and Phaneuf R A 2007 Phys. Rev. A 75 062712] with a resolution of 80 meV than their theoretical results. The contributions of the two experimental unresolved transitions are distinguished in our calculations, which show that the transitions from the ground state also make significant contributions to some resonances. Our theoretical results are also in good agreement with the measurements for the first resonance with a higher resolution of 20 meV.展开更多
Eutrophication and harmful cyanobacterial blooms threaten water resources all over the world.There is a great controversy about controlling only phosphorus or controlling both nitrogen and phosphorus in the management...Eutrophication and harmful cyanobacterial blooms threaten water resources all over the world.There is a great controversy about controlling only phosphorus or controlling both nitrogen and phosphorus in the management of lake eutrophication.The primary argument against the dual nutrients control of eutrophication is that nitrogen fixation can compensate the nitrogen deficits.Thus,it is of great necessary to study the factors that can significantly affect the nitrogen fixation.Due to the difference of climate and human influence,the water quality of different lakes(such as water temperature,N:P ratio and water residence time)is also quite different.Numerous studies have reported that the low N:P ratio can intensify the nitrogen fixation capacities.However,the effects of temperature and water residence time on the nitrogen fixation remain unclear.Thus,30 shallows freshwater lakes in the eastern plain of China were selected to measure dissolved N_(2) and Ar concentrations through N_(2):Ar method using a membrane inlet mass spectrometer to quantify the nitrogen fixation capacities and investigate whether the temperature and water residence time have a great impact on nitrogen fixation.The results have shown that the short lake water residence time can severely inhibit the nitrogen fixation capacities through inhibiting the growth of nitrogenfixing cyanobacteria,changing the N:P ratio and resuspending the solids from sediments.Similarly,lakes with low water temperature also have a low nitrogen fixation capacity,suggesting that controlling nitrogen in such lakes is feasible if the growth of cyanobacteria is limited by nitrogen.展开更多
基金supported by the National Natural Foundation of China(No.40872149,40472100 and 40930419)
文摘The uplift of the Ailao Shan-Diancang Shan （ASDS） along the Ailao Shan-Red River （ASRR） shear zone is an important geological event in the southeastern margin of Qinghai-Tibet Plateau tectonic domain in the Late Cenozoic, and it preserves important information on the structures, exhumationai history and tectonic evolution of the ASRR shear zone. The uplift structural mode and uplift timing of the ASDS is currently an important scientific topic for understanding the ASDS formation and late stage movements and evolution of the ASRR shear zone. The formation of the ASDS has been widely considered to be the consequence of the strike-slip movements of the ASRR shear zone. However, the shaping of geomorphic units is generally direct results of the latest tectonic activities. In this study, we investigated the timing and uplift structural mechanism of the ASDS and provided the following lines of supportive evidence. Firstly, the primary tectonic foliation of the ASDS shows significant characteristic variations, with steeply dipping tectonic foliation developed on the east side of the ASDS and the relatively horizontal foliation on the west side. Secondly, from northeast to southwest direction, the deformation and metamorphism gradually weakened and this zone can be further divided into three different metamorphic degree belts. Thirdly, the contact relationship between the ASDS and the Chuxiong basin-Erhai lake is a normal fault contact which can be found on the east side of the ASDS. 40^Ar/^39 Argeochronology suggests that the Diancang Shan had experienced a fast cooling event during 3-4 Ma. The apatite fission track testing method gives the age of 6.6-10.7 Ma in the Diancang Shan and 4.6-8.4 Ma in the Ailao Shan, respectively. Therefore the uplift of the ASDS can be explained by tilted block mode in which the east side was uplifted much higher than the west side, and it is not main reason of the shearing movements of the ASRR shear zone. The most recent uplift stages of the ASDS happened in the Pliocene （3-4 Ma） and Late Miocene （6-10 Ma）.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11179041 and 11275029)
文摘The 3s–np photoionization processes of the ground state 2P1/2 and the metastable state 2P3/2 of Ar5＋ are investigated using our recently developed relativistic R-matrix code, where the interactions between the bound states and the continuum states are included. Both resonance positions and the oscillator strengths are in much better agreement with the absolute experimental measurements by Wang et al.[Wang J C, Lu M, Esteves D, Habibi M, Alna’washi G and Phaneuf R A 2007 Phys. Rev. A 75 062712] with a resolution of 80 meV than their theoretical results. The contributions of the two experimental unresolved transitions are distinguished in our calculations, which show that the transitions from the ground state also make significant contributions to some resonances. Our theoretical results are also in good agreement with the measurements for the first resonance with a higher resolution of 20 meV.
基金jointly supported by the National Natural Science Foundation of China(Nos.41830757,41573076 and 41671494)。
文摘Eutrophication and harmful cyanobacterial blooms threaten water resources all over the world.There is a great controversy about controlling only phosphorus or controlling both nitrogen and phosphorus in the management of lake eutrophication.The primary argument against the dual nutrients control of eutrophication is that nitrogen fixation can compensate the nitrogen deficits.Thus,it is of great necessary to study the factors that can significantly affect the nitrogen fixation.Due to the difference of climate and human influence,the water quality of different lakes(such as water temperature,N:P ratio and water residence time)is also quite different.Numerous studies have reported that the low N:P ratio can intensify the nitrogen fixation capacities.However,the effects of temperature and water residence time on the nitrogen fixation remain unclear.Thus,30 shallows freshwater lakes in the eastern plain of China were selected to measure dissolved N_(2) and Ar concentrations through N_(2):Ar method using a membrane inlet mass spectrometer to quantify the nitrogen fixation capacities and investigate whether the temperature and water residence time have a great impact on nitrogen fixation.The results have shown that the short lake water residence time can severely inhibit the nitrogen fixation capacities through inhibiting the growth of nitrogenfixing cyanobacteria,changing the N:P ratio and resuspending the solids from sediments.Similarly,lakes with low water temperature also have a low nitrogen fixation capacity,suggesting that controlling nitrogen in such lakes is feasible if the growth of cyanobacteria is limited by nitrogen.
