The variation in Arctic sea ice has significant implications for climate change due to its huge influence on the global heat balance. In this study, we quantified the spatio-temporal variation of Arctic sea ice distri...The variation in Arctic sea ice has significant implications for climate change due to its huge influence on the global heat balance. In this study, we quantified the spatio-temporal variation of Arctic sea ice distribution using Advanced Microwave Scanning Radiometer(AMSR-E) sea-ice concentration data from 2003 to 2013. The results found that, over this period, the extent of sea ice reached a maximum in 2004, whereas in 2007 and 2012, the extent of summer sea ice was at a minimum. It declined continuously from 2010 to 2012, falling to its lowest level since 2003. Sea-ice extent fell continuously each summer between July and mid-September before increasing again. It decreased most rapidly in September, and the summer reduction rate was 1.35 × 10~5 km^2/yr, twice as fast as the rate between 1979 and 2006, and slightly slower than from 2002 to 2011. Area with >90% sea-ice concentration decreased by 1.32 × 10~7 km^2/yr, while locations with >50% sea-ice concentration, which were mainly covered by perennial ice, were near the North Pole, the Beaufort Sea, and the Queen Elizabeth Islands. Perennial Arctic ice decreased at a rate of 1.54 × 10~5 km^2 annually over the past 11 years.展开更多
Objection:The purpose of this study is preliminarily to discuss stomach perfusion imaging technique with Multi-slice CT and its clinical application value in stomach neoplasm.Methods:Fifteen patients with known stomac...Objection:The purpose of this study is preliminarily to discuss stomach perfusion imaging technique with Multi-slice CT and its clinical application value in stomach neoplasm.Methods:Fifteen patients with known stomach neoplasm performed perfusion imaging with 4 or 16 slice CT.Performing perfusion imaging in central slice of neoplasm,using CT cine scan,slice thick 10 mm/2i;with high pressure syringe,injecting quickly from right elbow-front vein,dosage 45-50 mL,injec-tion rate 3.5-4.0 mL/s,scanning delay time 5 s,scanning total time 45 s.We performed perfusion CT post-processing using pancreatic mode of perfusion CT software.Blood flow(BF),blood volume(BV),mean transit time(MTT),and permeability surface(PS) of gastric wall and tumor were computed for every case.Results:BF,BV,MTT and PS of gastric tumor were 116.68 ± 90.09 mL/(min·100 g),9.57 ± 8.12 mL/100 g,10.07 ± 7.74 s,20.78 ± 19.68 mL/(min·100g),respectively.The P values for each CT perfusion parameters between gastric tumor and normal gastric wall were 0.001,0.021,0.155 and 0.031,respectively.Conclusion:Perfusion CT can provide hemodynamics of gastric tumors and play a key role in the diagnosis of gastric tumors.It's clinical application prospect will be fully broad.展开更多
We investigate the properties of entanglement between an isolated atom and a Jaynes-Cummings atom in the presence of transient effects. These effects are due to the modulation of the atom-field coupling whose explicit...We investigate the properties of entanglement between an isolated atom and a Jaynes-Cummings atom in the presence of transient effects. These effects are due to the modulation of the atom-field coupling whose explicit time-dependence is considered for the case of the linear sweep. We show that the sudden death of entanglement can be controlled by the transient effects. These effects can suppress the sudden death of entanglement in time.展开更多
基金Under the auspices of National Natural Science Foundation of China(No.41676171)Qingdao National Laboratory for Marine Science and Technology of China(No.2016ASKJ02)+1 种基金Natural Science Foundation of Shandong(No.ZR2015DM015)Yantai Science&Technology Project(No.2013ZH094)
文摘The variation in Arctic sea ice has significant implications for climate change due to its huge influence on the global heat balance. In this study, we quantified the spatio-temporal variation of Arctic sea ice distribution using Advanced Microwave Scanning Radiometer(AMSR-E) sea-ice concentration data from 2003 to 2013. The results found that, over this period, the extent of sea ice reached a maximum in 2004, whereas in 2007 and 2012, the extent of summer sea ice was at a minimum. It declined continuously from 2010 to 2012, falling to its lowest level since 2003. Sea-ice extent fell continuously each summer between July and mid-September before increasing again. It decreased most rapidly in September, and the summer reduction rate was 1.35 × 10~5 km^2/yr, twice as fast as the rate between 1979 and 2006, and slightly slower than from 2002 to 2011. Area with >90% sea-ice concentration decreased by 1.32 × 10~7 km^2/yr, while locations with >50% sea-ice concentration, which were mainly covered by perennial ice, were near the North Pole, the Beaufort Sea, and the Queen Elizabeth Islands. Perennial Arctic ice decreased at a rate of 1.54 × 10~5 km^2 annually over the past 11 years.
基金Supported by the Young Foundation of the Department of Education,Liaoning Province (No.2005120)
文摘Objection:The purpose of this study is preliminarily to discuss stomach perfusion imaging technique with Multi-slice CT and its clinical application value in stomach neoplasm.Methods:Fifteen patients with known stomach neoplasm performed perfusion imaging with 4 or 16 slice CT.Performing perfusion imaging in central slice of neoplasm,using CT cine scan,slice thick 10 mm/2i;with high pressure syringe,injecting quickly from right elbow-front vein,dosage 45-50 mL,injec-tion rate 3.5-4.0 mL/s,scanning delay time 5 s,scanning total time 45 s.We performed perfusion CT post-processing using pancreatic mode of perfusion CT software.Blood flow(BF),blood volume(BV),mean transit time(MTT),and permeability surface(PS) of gastric wall and tumor were computed for every case.Results:BF,BV,MTT and PS of gastric tumor were 116.68 ± 90.09 mL/(min·100 g),9.57 ± 8.12 mL/100 g,10.07 ± 7.74 s,20.78 ± 19.68 mL/(min·100g),respectively.The P values for each CT perfusion parameters between gastric tumor and normal gastric wall were 0.001,0.021,0.155 and 0.031,respectively.Conclusion:Perfusion CT can provide hemodynamics of gastric tumors and play a key role in the diagnosis of gastric tumors.It's clinical application prospect will be fully broad.
文摘We investigate the properties of entanglement between an isolated atom and a Jaynes-Cummings atom in the presence of transient effects. These effects are due to the modulation of the atom-field coupling whose explicit time-dependence is considered for the case of the linear sweep. We show that the sudden death of entanglement can be controlled by the transient effects. These effects can suppress the sudden death of entanglement in time.
