The Academy of Aerospace Liquid Propulsion Technology (AALPT) successfully completed the long-duration captive firing test of a new generation of 120-ton thrust liquid oxygen/kerosene rocket engine. The engine had bee...The Academy of Aerospace Liquid Propulsion Technology (AALPT) successfully completed the long-duration captive firing test of a new generation of 120-ton thrust liquid oxygen/kerosene rocket engine. The engine had been stored for three years展开更多
The Afro-Asian summer monsoon is a zonally planetary-scale system, with a large-scale rainbelt covering Africa, South Asia and East Asia on interdecadal timescales both in the past century（1901-2014） and during the ...The Afro-Asian summer monsoon is a zonally planetary-scale system, with a large-scale rainbelt covering Africa, South Asia and East Asia on interdecadal timescales both in the past century（1901-2014） and during the last three decades（1979-2014）. A recent abrupt change of precipitation occurred in the late 1990 s. Since then, the entire rainbelt of the Afro-Asia monsoon system has advanced northwards in a coordinated way. Consistent increases in precipitation over the Huanghe-Huaihe River valley and the Sahel are associated with the teleconnection pattern excited by the warm phase of the Atlantic Multidecadal Oscillation（AMO）. A teleconnection wave train, with alternating cyclones/anticyclones, is detected in the upper troposphere. Along the teleconnection path, the configuration of circulation anomalies in North Africa is characterized by coupling of the upper-level anticyclone（divergence） with low-level thermal low pressure（convergence）, facilitating the initiation and development of ascending motions in the Sahel. Similarly, in East Asia, a coupled circulation pattern also excites ascending motion in the Huanghe-Huaihe River valley. The synchronous increase in precipitation over the Sahel and Huanghe-Huaihe River valley can be attributed to the co-occurrences and in-phase changes of ascending motion. On the other hand, the warm phase of the AMO results in significant warming in the upper troposphere in North Africa and the northern part of East Asia. Such warming contributes to intensification of the tropical easterly jet through increasing the meridional pressure gradient both at the entrance region（East Asia） and the exit region（Africa）. Accordingly, precipitation over the Sahel and Huanghe-Huaihe River valley intensifies, owing to ageostrophic secondary cells. The results of this study provide evidence for a consistent and holistic interdecadal change in the Afro-Asian summer monsoon.展开更多
The geogas collectors showing a geogas anomaly in field geogas prospecting and in simulation tests were selected for the observation under high resolution microscopy. The result demonstrates that the geogas matter is ...The geogas collectors showing a geogas anomaly in field geogas prospecting and in simulation tests were selected for the observation under high resolution microscopy. The result demonstrates that the geogas matter is transported in the form of nano-scale particles with a size of aboutN nm to N-10 nm, and accumulated into aggregations of 1-2 μm to N.10 μm, with globular and film shape, and the component of Cu, Zn, Cr, Au, Al, V, Si, Br, C1, S, Ca, etc. Based on the knowledge of nano science and technique, the mechanism of the geogas prospecting and its significance in geology and mineral prospecting are discussed.展开更多
文摘The Academy of Aerospace Liquid Propulsion Technology (AALPT) successfully completed the long-duration captive firing test of a new generation of 120-ton thrust liquid oxygen/kerosene rocket engine. The engine had been stored for three years
基金supported by the National Basic Research Program of China(Grant Nos.2013CB430203 and 2012CB417205)the National Key Research and Development Program of China(during the 13th Five-year Plan)(Grant No.2016YFA0601501)the China Meteorological Special Programs(Grant No.GYHY201306033)
文摘The Afro-Asian summer monsoon is a zonally planetary-scale system, with a large-scale rainbelt covering Africa, South Asia and East Asia on interdecadal timescales both in the past century（1901-2014） and during the last three decades（1979-2014）. A recent abrupt change of precipitation occurred in the late 1990 s. Since then, the entire rainbelt of the Afro-Asia monsoon system has advanced northwards in a coordinated way. Consistent increases in precipitation over the Huanghe-Huaihe River valley and the Sahel are associated with the teleconnection pattern excited by the warm phase of the Atlantic Multidecadal Oscillation（AMO）. A teleconnection wave train, with alternating cyclones/anticyclones, is detected in the upper troposphere. Along the teleconnection path, the configuration of circulation anomalies in North Africa is characterized by coupling of the upper-level anticyclone（divergence） with low-level thermal low pressure（convergence）, facilitating the initiation and development of ascending motions in the Sahel. Similarly, in East Asia, a coupled circulation pattern also excites ascending motion in the Huanghe-Huaihe River valley. The synchronous increase in precipitation over the Sahel and Huanghe-Huaihe River valley can be attributed to the co-occurrences and in-phase changes of ascending motion. On the other hand, the warm phase of the AMO results in significant warming in the upper troposphere in North Africa and the northern part of East Asia. Such warming contributes to intensification of the tropical easterly jet through increasing the meridional pressure gradient both at the entrance region（East Asia） and the exit region（Africa）. Accordingly, precipitation over the Sahel and Huanghe-Huaihe River valley intensifies, owing to ageostrophic secondary cells. The results of this study provide evidence for a consistent and holistic interdecadal change in the Afro-Asian summer monsoon.
文摘The geogas collectors showing a geogas anomaly in field geogas prospecting and in simulation tests were selected for the observation under high resolution microscopy. The result demonstrates that the geogas matter is transported in the form of nano-scale particles with a size of aboutN nm to N-10 nm, and accumulated into aggregations of 1-2 μm to N.10 μm, with globular and film shape, and the component of Cu, Zn, Cr, Au, Al, V, Si, Br, C1, S, Ca, etc. Based on the knowledge of nano science and technique, the mechanism of the geogas prospecting and its significance in geology and mineral prospecting are discussed.
