Opening up effect belt in dahurian larch (Larix gmelini) plantation can significantly promote the growth and development of manchurian ash (Fraxinus mandshur-ica) natural regcneration seedlings. The quantity, growth a...Opening up effect belt in dahurian larch (Larix gmelini) plantation can significantly promote the growth and development of manchurian ash (Fraxinus mandshur-ica) natural regcneration seedlings. The quantity, growth and distribution characters of manchurian ash natural regeneration seedling and the seed quantity of manchurian ash on the effect belt are significantly much more than that on remained belt. It provides a theoretical basis for using the management method of - Cutting coniferous to introduce broadleal trees in the coniferous stand, improving the stand structure, increasing the ecological stability and biological productivity.展开更多
The accumulated sand-belts have formed along the oasis fringe, especially at the upwind areas of the desert area in Gansu Hexi of China during the process of desert control in recent 60 years. The accumulated sand-bel...The accumulated sand-belts have formed along the oasis fringe, especially at the upwind areas of the desert area in Gansu Hexi of China during the process of desert control in recent 60 years. The accumulated sand-belt is a byproduct of desertifieation combating through afforestation and barriers-setting. This pa- per analyzed the data （ including wind velocity/direction） of 21 sites on the accumulated sand-belt to evaluate its stability and ecological effects. The results showed that the accumulated sand-belt is in a stable state. It plays a significant role in weakening wind and this effect is enhanced with the increase of wind velocity. The height of accumulated sand-belt is an important factor characterizing its windproof function. When the wind velocity is higher than 2 m/s, the windproof area in the downwind places is 20 times greater than the height of the accumulated sand-beh. When the wind velocity is higher than 8 m/s, the wind velocity on the top of the accumulated sand-belt is less than that in the upwind open areas. When the air flow reaches the windward slope, its energy is released and reduced by uplifting along the slope and diversion towards the two wings. Wind deflector reduces the velocity of the prevailing wind on the windward slope.展开更多
This paper analyzes the origin of the Belt and Road Initiative, the role of China's market-oriented development of natural gas in promoting the Belt and Road Initiative, and the possibilities of natural gas cooper...This paper analyzes the origin of the Belt and Road Initiative, the role of China's market-oriented development of natural gas in promoting the Belt and Road Initiative, and the possibilities of natural gas cooperation between China and countries along the Belt and Road. In this paper, the implementation of the natural gas strategy under the Belt and Road Initiative and how it will promote the development of the natural gas industry chain are reviewed. The risks of implementing the Belt and Road Initiative are analyzed, especially in terms of the pricing mechanism, geopolitical risks, and seasonal risks.展开更多
The 1°×1° distribution map of crustmantle structural ratio R for the lithosphere along the Longitudinal Seismic Belt of China has been compiled using computer based on the results of geophysical prospec...The 1°×1° distribution map of crustmantle structural ratio R for the lithosphere along the Longitudinal Seismic Belt of China has been compiled using computer based on the results of geophysical prospecting by previous researchers, and the latest results by the present authors. Based on this map, an insight into the structural features of the crustmantle assemblage along the Longitudinal Seismic Belt has been gained, while their relation to seismic activity and the distributions of geothermal flux and intracrustal high conductivitylow velocity layers, as well as their tectonic effect to seismicity have been discussed.展开更多
The mutual-belt selective cutting was conducted in the secondary poplar-birch forests. The changes of environmental factors after cutting were observed. The environmental factors of effect belts(cutting belts) of 15m ...The mutual-belt selective cutting was conducted in the secondary poplar-birch forests. The changes of environmental factors after cutting were observed. The environmental factors of effect belts(cutting belts) of 15m in width had great changes. 10-m effect belts had unnoticed changes in environmental factors. The reserved belts with 10-m effect belts had a greater increase in DBH growth rate and volume growth rate. The reserved belts for 6-m and 8-m effect belts had lower increase in DBH and volume. The environmental factors of 6-m and 8-m effect belts did not change much. comparing with their reserved belts. Cluster analysis and principal component analysis for environmental factors between each two belts were also made. and the results proved that 10-m cutting belt is the best way for management of the secondary poplar-birch forests.展开更多
DHS(DongHe Sandstone) reservoir is one of the main reservoirs in Hadexun, Tarim basin. Based on reprocessed high-resolution seismic data, the forward model was investigated. Under the guidance of model combining with ...DHS(DongHe Sandstone) reservoir is one of the main reservoirs in Hadexun, Tarim basin. Based on reprocessed high-resolution seismic data, the forward model was investigated. Under the guidance of model combining with well data in the research area, the methodology of recognizing DHS pinch-out was discussed in detail. The result is helpful for the research of DHS pinch-out reservoirs in Tarim basin and for the exploration of this type of reservoir in China.展开更多
We have studied a reformed type of the classic restricted three-body problem where the bigger primary is radiating and the smaller primary is oblate;and they are encompassed by a homogeneous circular cluster of materi...We have studied a reformed type of the classic restricted three-body problem where the bigger primary is radiating and the smaller primary is oblate;and they are encompassed by a homogeneous circular cluster of material points centered at the mass center of the system (belt). In this dynamical model, we have derived the equations that govern the motion of the infinitesimal mass under the effects of oblateness up to the zonal harmonics J4 of the smaller primary, radiation of the bigger primary and the gravitational potential generated by the belt. Numerically, we have found that, in addition to the three collinear libration points Li (i = 1, 2, 3) in the classic restricted three-body problem, there appear four more collinear points Lni (i = 1, 2, 3, 4). Ln1 and Ln2 result due to the potential from the belt, while Ln3 and Ln4 are consequences of the oblateness up to the zonal harmonics J4 of the smaller primary. Owing to the mutual effect of all the perturbations, L1 and L3 come nearer to the primaries while Ln3 advances away from the primaries;and L2 and Ln1 tend towards the smaller primary whereas Ln2 and Ln4 draw closer to the bigger primary. The collinear libration points Li (i = 1, 2, 3) and Ln2 are linearly unstable whereas the Ln1, Ln3 and Ln4 are linearly stable. A practical application of this model could be the study of motion of a dust particle near a radiating star and an oblate body surrounded by a belt.展开更多
As the structural body related to temporal-spatial evolution and tectonic dynamic system, the orogenic belt and basin are not only dependent on each other in space but also closely related with each other in terms of ...As the structural body related to temporal-spatial evolution and tectonic dynamic system, the orogenic belt and basin are not only dependent on each other in space but also closely related with each other in terms of infrastructure, matter transference and dynamic mechanisms. By using apatite fission-track method, the authors firstly analyze the uplift and denudation ratios of the Qinling-Dabie orogenic belt, and by using tectonically deformed combination analysis and tectonic-thermal simulation the main geological occurrences are also illustrated. It is found that there must have had multi-phase differential uplift and denudation phenomena in the Qinling-Dabie orogenic belt during the Mesozoic-Cenozoic. Then, the regional evolution pattern of qualitative and quantitative denudation process is obtained during the post-orogenic period. On the basis of summarizing evolution process of the basin-range system in the Qinling-Dabie orogenic belt during the Mesozoic-Cenozoic and its effects on regional environment, the influence of evolution process on geomorphologic landscapes change, water system vicissitude, eco-environment succession and drainage basin system evolution is discussed.展开更多
文摘Opening up effect belt in dahurian larch (Larix gmelini) plantation can significantly promote the growth and development of manchurian ash (Fraxinus mandshur-ica) natural regcneration seedlings. The quantity, growth and distribution characters of manchurian ash natural regeneration seedling and the seed quantity of manchurian ash on the effect belt are significantly much more than that on remained belt. It provides a theoretical basis for using the management method of - Cutting coniferous to introduce broadleal trees in the coniferous stand, improving the stand structure, increasing the ecological stability and biological productivity.
基金Supported by National Natural Science Foundation of China(41261102)
文摘The accumulated sand-belts have formed along the oasis fringe, especially at the upwind areas of the desert area in Gansu Hexi of China during the process of desert control in recent 60 years. The accumulated sand-belt is a byproduct of desertifieation combating through afforestation and barriers-setting. This pa- per analyzed the data （ including wind velocity/direction） of 21 sites on the accumulated sand-belt to evaluate its stability and ecological effects. The results showed that the accumulated sand-belt is in a stable state. It plays a significant role in weakening wind and this effect is enhanced with the increase of wind velocity. The height of accumulated sand-belt is an important factor characterizing its windproof function. When the wind velocity is higher than 2 m/s, the windproof area in the downwind places is 20 times greater than the height of the accumulated sand-beh. When the wind velocity is higher than 8 m/s, the wind velocity on the top of the accumulated sand-belt is less than that in the upwind open areas. When the air flow reaches the windward slope, its energy is released and reduced by uplifting along the slope and diversion towards the two wings. Wind deflector reduces the velocity of the prevailing wind on the windward slope.
文摘This paper analyzes the origin of the Belt and Road Initiative, the role of China's market-oriented development of natural gas in promoting the Belt and Road Initiative, and the possibilities of natural gas cooperation between China and countries along the Belt and Road. In this paper, the implementation of the natural gas strategy under the Belt and Road Initiative and how it will promote the development of the natural gas industry chain are reviewed. The risks of implementing the Belt and Road Initiative are analyzed, especially in terms of the pricing mechanism, geopolitical risks, and seasonal risks.
文摘The 1°×1° distribution map of crustmantle structural ratio R for the lithosphere along the Longitudinal Seismic Belt of China has been compiled using computer based on the results of geophysical prospecting by previous researchers, and the latest results by the present authors. Based on this map, an insight into the structural features of the crustmantle assemblage along the Longitudinal Seismic Belt has been gained, while their relation to seismic activity and the distributions of geothermal flux and intracrustal high conductivitylow velocity layers, as well as their tectonic effect to seismicity have been discussed.
文摘The mutual-belt selective cutting was conducted in the secondary poplar-birch forests. The changes of environmental factors after cutting were observed. The environmental factors of effect belts(cutting belts) of 15m in width had great changes. 10-m effect belts had unnoticed changes in environmental factors. The reserved belts with 10-m effect belts had a greater increase in DBH growth rate and volume growth rate. The reserved belts for 6-m and 8-m effect belts had lower increase in DBH and volume. The environmental factors of 6-m and 8-m effect belts did not change much. comparing with their reserved belts. Cluster analysis and principal component analysis for environmental factors between each two belts were also made. and the results proved that 10-m cutting belt is the best way for management of the secondary poplar-birch forests.
文摘DHS(DongHe Sandstone) reservoir is one of the main reservoirs in Hadexun, Tarim basin. Based on reprocessed high-resolution seismic data, the forward model was investigated. Under the guidance of model combining with well data in the research area, the methodology of recognizing DHS pinch-out was discussed in detail. The result is helpful for the research of DHS pinch-out reservoirs in Tarim basin and for the exploration of this type of reservoir in China.
文摘We have studied a reformed type of the classic restricted three-body problem where the bigger primary is radiating and the smaller primary is oblate;and they are encompassed by a homogeneous circular cluster of material points centered at the mass center of the system (belt). In this dynamical model, we have derived the equations that govern the motion of the infinitesimal mass under the effects of oblateness up to the zonal harmonics J4 of the smaller primary, radiation of the bigger primary and the gravitational potential generated by the belt. Numerically, we have found that, in addition to the three collinear libration points Li (i = 1, 2, 3) in the classic restricted three-body problem, there appear four more collinear points Lni (i = 1, 2, 3, 4). Ln1 and Ln2 result due to the potential from the belt, while Ln3 and Ln4 are consequences of the oblateness up to the zonal harmonics J4 of the smaller primary. Owing to the mutual effect of all the perturbations, L1 and L3 come nearer to the primaries while Ln3 advances away from the primaries;and L2 and Ln1 tend towards the smaller primary whereas Ln2 and Ln4 draw closer to the bigger primary. The collinear libration points Li (i = 1, 2, 3) and Ln2 are linearly unstable whereas the Ln1, Ln3 and Ln4 are linearly stable. A practical application of this model could be the study of motion of a dust particle near a radiating star and an oblate body surrounded by a belt.
文摘As the structural body related to temporal-spatial evolution and tectonic dynamic system, the orogenic belt and basin are not only dependent on each other in space but also closely related with each other in terms of infrastructure, matter transference and dynamic mechanisms. By using apatite fission-track method, the authors firstly analyze the uplift and denudation ratios of the Qinling-Dabie orogenic belt, and by using tectonically deformed combination analysis and tectonic-thermal simulation the main geological occurrences are also illustrated. It is found that there must have had multi-phase differential uplift and denudation phenomena in the Qinling-Dabie orogenic belt during the Mesozoic-Cenozoic. Then, the regional evolution pattern of qualitative and quantitative denudation process is obtained during the post-orogenic period. On the basis of summarizing evolution process of the basin-range system in the Qinling-Dabie orogenic belt during the Mesozoic-Cenozoic and its effects on regional environment, the influence of evolution process on geomorphologic landscapes change, water system vicissitude, eco-environment succession and drainage basin system evolution is discussed.
