At present,export of China's agricultural products is faced with many trade barriers,especially technological barriers.Trade barriers include(1)technological barriers(such as quarantine and inspection barrier,iden...At present,export of China's agricultural products is faced with many trade barriers,especially technological barriers.Trade barriers include(1)technological barriers(such as quarantine and inspection barrier,identity certification/authentication barrier and labeling rules barrier);(2)trade remedy barrier;(3)other non-tariff barriers(NTB).Through positioning and analysis of trade barriers of China's agricultural products,it is known that technological barriers should not be deemed unreasonable totally.Some barriers also have certain positive significance.To respond to trade barriers,it comes up with countermeasures and recommendations from the perspective of agricultural producers and government.Agricultural producers should actively improve product quality,abide by requirement of importers,and treat quarantine and inspection in a rational manner;government should supply information and issue early warning,assist domestic producers in responding to lawsuits,and take advantage of WTO platform to solve trade disputes.展开更多
In the later stage of water-injected reservoir development, the remaining oil is highly dispersed, and the first task to improve the development effect is to finely depict the distribution law of the remaining oil. Ta...In the later stage of water-injected reservoir development, the remaining oil is highly dispersed, and the first task to improve the development effect is to finely depict the distribution law of the remaining oil. Taking Block J as an example, this paper comprehensively uses drilling coring, logging, dynamic monitoring and other data, and uses dynamic monitoring analysis technology, logging secondary interpretation technology, coring analysis technology, micro-structure identification technology, etc. to clarify the distribution law of remaining oil on the plane, between layers and within layers, and formulates reasonable technical countermeasures for different remaining oil distribution patterns, including sidetracking potential tapping, improving injection-production well pattern, optimizing injection-production well sections, strengthening water injection in potential layers, optimizing perforation well sections, etc. Good results have been achieved, with an increase in oil production of 120 tons and a gradual increase in oil production of 60,000 tons. Indicators such as the water cut increase rate and natural decline rate of the block have been improved. It is estimated that the ultimate recovery rate of water flooding is 35.5%, which is 5.5 percentage points higher than the nominal recovery rate. The recoverable reserves have been increased by 1.425 million tons, and the development life of the block has been prolonged. The results and understanding obtained can provide reference for other oil reservoirs.展开更多
The circadian clock and sleep are essential for human physiology and behavior; deregulation of circadian rhythms impairs health and performance. Circadian clocks and sleep evolved to adapt to Earth's environment, ...The circadian clock and sleep are essential for human physiology and behavior; deregulation of circadian rhythms impairs health and performance. Circadian clocks and sleep evolved to adapt to Earth's environment, which is characterized by a 24-hour light–dark cycle. Changes in gravity load, lighting and work schedules during spaceflight missions can impact circadian clocks and disrupt sleep, in turn jeopardizing the mood, cognition and performance of orbiting astronauts. In this review, we summarize our understanding of both the influence of the space environment on the circadian timing system and sleep and the impact of these changes on astronaut physiology and performance.展开更多
文摘At present,export of China's agricultural products is faced with many trade barriers,especially technological barriers.Trade barriers include(1)technological barriers(such as quarantine and inspection barrier,identity certification/authentication barrier and labeling rules barrier);(2)trade remedy barrier;(3)other non-tariff barriers(NTB).Through positioning and analysis of trade barriers of China's agricultural products,it is known that technological barriers should not be deemed unreasonable totally.Some barriers also have certain positive significance.To respond to trade barriers,it comes up with countermeasures and recommendations from the perspective of agricultural producers and government.Agricultural producers should actively improve product quality,abide by requirement of importers,and treat quarantine and inspection in a rational manner;government should supply information and issue early warning,assist domestic producers in responding to lawsuits,and take advantage of WTO platform to solve trade disputes.
文摘In the later stage of water-injected reservoir development, the remaining oil is highly dispersed, and the first task to improve the development effect is to finely depict the distribution law of the remaining oil. Taking Block J as an example, this paper comprehensively uses drilling coring, logging, dynamic monitoring and other data, and uses dynamic monitoring analysis technology, logging secondary interpretation technology, coring analysis technology, micro-structure identification technology, etc. to clarify the distribution law of remaining oil on the plane, between layers and within layers, and formulates reasonable technical countermeasures for different remaining oil distribution patterns, including sidetracking potential tapping, improving injection-production well pattern, optimizing injection-production well sections, strengthening water injection in potential layers, optimizing perforation well sections, etc. Good results have been achieved, with an increase in oil production of 120 tons and a gradual increase in oil production of 60,000 tons. Indicators such as the water cut increase rate and natural decline rate of the block have been improved. It is estimated that the ultimate recovery rate of water flooding is 35.5%, which is 5.5 percentage points higher than the nominal recovery rate. The recoverable reserves have been increased by 1.425 million tons, and the development life of the block has been prolonged. The results and understanding obtained can provide reference for other oil reservoirs.
基金supported by the National Basic Program of China (2011CB711000 and 2012CB947600)the National Natural Science Foundation of China (31171119, 31171010, 31171049, 31121061, 31271164)Open Fund from Key Laboratory for Space Biosciences & Biotechnology, Northwestern Polytechnical University (2013KF1501)
文摘The circadian clock and sleep are essential for human physiology and behavior; deregulation of circadian rhythms impairs health and performance. Circadian clocks and sleep evolved to adapt to Earth's environment, which is characterized by a 24-hour light–dark cycle. Changes in gravity load, lighting and work schedules during spaceflight missions can impact circadian clocks and disrupt sleep, in turn jeopardizing the mood, cognition and performance of orbiting astronauts. In this review, we summarize our understanding of both the influence of the space environment on the circadian timing system and sleep and the impact of these changes on astronaut physiology and performance.
