Three generation systems, namely, steam Rankine cycle （SRC）, organic Rankine cycle （ORC）, and steam-organic combined Rankine cycle （S-ORC）, were simulated using the Engineering Equation Solver fEES） to efficien...Three generation systems, namely, steam Rankine cycle （SRC）, organic Rankine cycle （ORC）, and steam-organic combined Rankine cycle （S-ORC）, were simulated using the Engineering Equation Solver fEES） to efficiently utilize flue gas emissions from 200 to 450 ℃ in iron and steel plants. Based on the simulation results for thermal efficiency, exergy efficiency, and power generation, the performances of the three power generation systems were compared and analyzed. To further utilize waste heat from the turbine exhaust steam of the ORC system, cas- cade （）RC （CORC） was designed for heat sources above 300 ℃. Based on a comprehensive performance comparison, the application of the ORC using R141b is preferable for 200 to 300 ℃ flue gas. For 300 to 450 ℃ flue gas, CORC is an alternative technology to improve the efficiency and quality of waste heat utilization. For flue gas above 450 ℃, S-ORC can achieve higher efficiency and power generation than conventional SRC, with a relatively small negative pressure and high dryness of the turbine outlet steam. Hence, S-ORC can be considered as a substitute for SRC.展开更多
1.Objective Dunhuang Basin is the largest area and the third hydrocarbon resources potential basin among the basins of Hexi Corridor,and also a low exploration degree basin.The source rock position,characteristics and...1.Objective Dunhuang Basin is the largest area and the third hydrocarbon resources potential basin among the basins of Hexi Corridor,and also a low exploration degree basin.The source rock position,characteristics and hydrocarbon generating potential of residual Mid-Lower Jurassic are still unknown.The project is to ascertain the source rock development and hydrocarbon generating capacity of Mid-Lower Jurassic,to find out the resource potential,to delineate the resource prospect area and to optimize the favorable areas.It may direct the petroleum exploration in Dunhuang Basin.展开更多
Background: NCCN’s guidelines for the diagnosis and treatment of rectal cancer suggest that accurate preoperative clinical staging of rectal cancer is very important. Reliable preoperative evaluation is the key to th...Background: NCCN’s guidelines for the diagnosis and treatment of rectal cancer suggest that accurate preoperative clinical staging of rectal cancer is very important. Reliable preoperative evaluation is the key to the development of surgical protocols, in order to investigate the diagnostic value of digital rectal diagnosis for lymph node metastasis of middle and low rectal cancer. Methods: We prospectively performed digital rectal examination in 258 patients with mid-low rectal cancer before operation, to analyze the distance from the lower margin of the tumor to the margin of the anus, the diameter of the invasion of the intestinal wall of the tumor, the accuracy between the general type and depth of invasion of the tumor and the pathological results of the postoperative specimen, and the predictability of the lymph node metastasis rate of the rectal digital examination. Results: The results of the analysis showed that the above indicators and postoperative pathological findings have high accuracy. Conclusions: It is concluded that accurate and detailed digital rectal examination before operation can predict lymph node metastasis rate of mid-low rectal cancer at a higher level and accurately.展开更多
NCEP/NCAR daily reanalysis data and Chinese daily gridded precipitation data are used to study the relationship between an aprupt drought-flood transition over the mid-low reaches of the Yangtze River in 2011 and the ...NCEP/NCAR daily reanalysis data and Chinese daily gridded precipitation data are used to study the relationship between an aprupt drought-flood transition over the mid-low reaches of the Yangtze River in 2011 and the intraseasonal oscillation （ISO; 30-60 days） in the mid-high latitude meridional circulation of the upper troposphere over East Asia. The abrupt transition from drought to flood occurs in early June. The first two recovered fields of the complex empirical orthogonal function show that northward-propagating westerlies from low latitudes converge with southward-propagating westerlies from high latitudes over the mid-low reaches of the Yangtze River （MLRYR） in mid late May. The timing of this convergence corresponds to the flood period in early-mid June. The ISO index is significantly and positively correlated with rainfall over the MLRYR. During the dry phase （before the transition）, the upper troposphere over the MLRYR is characterized by cyclonic flow, easterly winds, and convergence. The regional circulation is dominated by a wave train with a cyclone over east of Lake Baikal, an anticyclone over northern China, and a cyclone over the MLRYR. During the wet phase, the situation is reversed. The configuration of the wave train during the dry phase favors the southward propagation of westerly wind disturbances, while the configuration of the wave train during the wet phase favors the development and maintenance of a pumping effect and sustained ascending motions over the MLRYR.展开更多
A continuous overcast-rainy weather(CORW) process occurred over the mid-lower reaches of the Yangtze River(MLRYR) in China from February 14 to March 9 in 2009,with a large stretch and long duration that was rarely see...A continuous overcast-rainy weather(CORW) process occurred over the mid-lower reaches of the Yangtze River(MLRYR) in China from February 14 to March 9 in 2009,with a large stretch and long duration that was rarely seen in historical records.Using the empirical orthogonal function(EOF),we analyzed the geopotential height anomaly field of the NCEP-DOE Reanalysis II in the same period,and defined the stable components of extended-range(10-30 days) weather forecast(ERWF).Furthermore,we defined anomalous and climatic stable components based on the variation characteristics of the variance contribution ratio of EOF components.The climatic stable components were able to explain the impact of climatically averaged information on the ERWF,and the anomalous stable components revealed the abnormal characteristics of the continuous overcast-rainy days.Our results show that the stable components,especially the anomalous stable components,can maintain the stability for a longer time(more than 10 days) and manifest as monthly scale low-frequency variation and ultra-long-wave activities.They also behave as ultra-long waves of planetary scale with a stable and vertically coherent structure,reflect the variation of general circulation in mid-high latitudes,display the cycle of the zonal circulation and the movement and adjustment of the ultra-long waves,and are closely linked to the surface CORW process.展开更多
The role of small bowel capsule endoscopy (CE) in suspected small bowel bleedingis well established and current European and other international guidelinesposition it as the first line test after negative bidirectiona...The role of small bowel capsule endoscopy (CE) in suspected small bowel bleedingis well established and current European and other international guidelinesposition it as the first line test after negative bidirectional endoscopies. Insuspected mid-lower gastrointestinal bleeding (MLGIB) the diagnostic yield ofcolonoscopy is poor and may cause a delay in detecting small bowel disease. Acrucial aspect of small bowel capsule endoscope performance is the timing of theprocedure, the interval between the bleeding episode and capsule ingestion isinversely related to the diagnostic yield as confirmed by a recent meta-analysis.Currently the ongoing advances achieved by video CE in particular to evaluateboth small bowel and colon in a single test using double headed capsules, raisesquestions regarding the position of pan intestinal capsule in the current algorithmto investigate patients presenting with suspected MLGIB ahead of colonoscopy.Early evidence suggests pan intestinal capsule could fit well as a diagnostic“filter” test in this cohort of patients, thereby reserving invasive conventionalcolonoscopy or device assisted enteroscopy as therapeutics options only. The recentdevelopment of magnetically controlled CE and a blood sensing capsule pushthe boundaries of CE even further in patients presenting with suspected gastrointestinalbleeding. This review will discuss the current available evidence andfuture directions of CE in suspected MLGIB.展开更多
基金Sponsored by Science and Technology Commission Foundation of Jiangsu Province of China(BA2010035)
文摘Three generation systems, namely, steam Rankine cycle （SRC）, organic Rankine cycle （ORC）, and steam-organic combined Rankine cycle （S-ORC）, were simulated using the Engineering Equation Solver fEES） to efficiently utilize flue gas emissions from 200 to 450 ℃ in iron and steel plants. Based on the simulation results for thermal efficiency, exergy efficiency, and power generation, the performances of the three power generation systems were compared and analyzed. To further utilize waste heat from the turbine exhaust steam of the ORC system, cas- cade （）RC （CORC） was designed for heat sources above 300 ℃. Based on a comprehensive performance comparison, the application of the ORC using R141b is preferable for 200 to 300 ℃ flue gas. For 300 to 450 ℃ flue gas, CORC is an alternative technology to improve the efficiency and quality of waste heat utilization. For flue gas above 450 ℃, S-ORC can achieve higher efficiency and power generation than conventional SRC, with a relatively small negative pressure and high dryness of the turbine outlet steam. Hence, S-ORC can be considered as a substitute for SRC.
文摘1.Objective Dunhuang Basin is the largest area and the third hydrocarbon resources potential basin among the basins of Hexi Corridor,and also a low exploration degree basin.The source rock position,characteristics and hydrocarbon generating potential of residual Mid-Lower Jurassic are still unknown.The project is to ascertain the source rock development and hydrocarbon generating capacity of Mid-Lower Jurassic,to find out the resource potential,to delineate the resource prospect area and to optimize the favorable areas.It may direct the petroleum exploration in Dunhuang Basin.
文摘Background: NCCN’s guidelines for the diagnosis and treatment of rectal cancer suggest that accurate preoperative clinical staging of rectal cancer is very important. Reliable preoperative evaluation is the key to the development of surgical protocols, in order to investigate the diagnostic value of digital rectal diagnosis for lymph node metastasis of middle and low rectal cancer. Methods: We prospectively performed digital rectal examination in 258 patients with mid-low rectal cancer before operation, to analyze the distance from the lower margin of the tumor to the margin of the anus, the diameter of the invasion of the intestinal wall of the tumor, the accuracy between the general type and depth of invasion of the tumor and the pathological results of the postoperative specimen, and the predictability of the lymph node metastasis rate of the rectal digital examination. Results: The results of the analysis showed that the above indicators and postoperative pathological findings have high accuracy. Conclusions: It is concluded that accurate and detailed digital rectal examination before operation can predict lymph node metastasis rate of mid-low rectal cancer at a higher level and accurately.
基金Supported by the National Natural Science Foundation of China (41221064 and 40875052)China Meteorological Administration Special Public Welfare Research Fund (GYHY200906017 and GYHY201006020)Basic Research Fund of the Chinese Academy of Meteorological Sciences (2010Z003)
文摘NCEP/NCAR daily reanalysis data and Chinese daily gridded precipitation data are used to study the relationship between an aprupt drought-flood transition over the mid-low reaches of the Yangtze River in 2011 and the intraseasonal oscillation （ISO; 30-60 days） in the mid-high latitude meridional circulation of the upper troposphere over East Asia. The abrupt transition from drought to flood occurs in early June. The first two recovered fields of the complex empirical orthogonal function show that northward-propagating westerlies from low latitudes converge with southward-propagating westerlies from high latitudes over the mid-low reaches of the Yangtze River （MLRYR） in mid late May. The timing of this convergence corresponds to the flood period in early-mid June. The ISO index is significantly and positively correlated with rainfall over the MLRYR. During the dry phase （before the transition）, the upper troposphere over the MLRYR is characterized by cyclonic flow, easterly winds, and convergence. The regional circulation is dominated by a wave train with a cyclone over east of Lake Baikal, an anticyclone over northern China, and a cyclone over the MLRYR. During the wet phase, the situation is reversed. The configuration of the wave train during the dry phase favors the southward propagation of westerly wind disturbances, while the configuration of the wave train during the wet phase favors the development and maintenance of a pumping effect and sustained ascending motions over the MLRYR.
基金supported by National Natural Science Foundation of China (Grant No.40930952)Science and Technology Supporting Project (Grant No.2009BAC51B04)
文摘A continuous overcast-rainy weather(CORW) process occurred over the mid-lower reaches of the Yangtze River(MLRYR) in China from February 14 to March 9 in 2009,with a large stretch and long duration that was rarely seen in historical records.Using the empirical orthogonal function(EOF),we analyzed the geopotential height anomaly field of the NCEP-DOE Reanalysis II in the same period,and defined the stable components of extended-range(10-30 days) weather forecast(ERWF).Furthermore,we defined anomalous and climatic stable components based on the variation characteristics of the variance contribution ratio of EOF components.The climatic stable components were able to explain the impact of climatically averaged information on the ERWF,and the anomalous stable components revealed the abnormal characteristics of the continuous overcast-rainy days.Our results show that the stable components,especially the anomalous stable components,can maintain the stability for a longer time(more than 10 days) and manifest as monthly scale low-frequency variation and ultra-long-wave activities.They also behave as ultra-long waves of planetary scale with a stable and vertically coherent structure,reflect the variation of general circulation in mid-high latitudes,display the cycle of the zonal circulation and the movement and adjustment of the ultra-long waves,and are closely linked to the surface CORW process.
文摘The role of small bowel capsule endoscopy (CE) in suspected small bowel bleedingis well established and current European and other international guidelinesposition it as the first line test after negative bidirectional endoscopies. Insuspected mid-lower gastrointestinal bleeding (MLGIB) the diagnostic yield ofcolonoscopy is poor and may cause a delay in detecting small bowel disease. Acrucial aspect of small bowel capsule endoscope performance is the timing of theprocedure, the interval between the bleeding episode and capsule ingestion isinversely related to the diagnostic yield as confirmed by a recent meta-analysis.Currently the ongoing advances achieved by video CE in particular to evaluateboth small bowel and colon in a single test using double headed capsules, raisesquestions regarding the position of pan intestinal capsule in the current algorithmto investigate patients presenting with suspected MLGIB ahead of colonoscopy.Early evidence suggests pan intestinal capsule could fit well as a diagnostic“filter” test in this cohort of patients, thereby reserving invasive conventionalcolonoscopy or device assisted enteroscopy as therapeutics options only. The recentdevelopment of magnetically controlled CE and a blood sensing capsule pushthe boundaries of CE even further in patients presenting with suspected gastrointestinalbleeding. This review will discuss the current available evidence andfuture directions of CE in suspected MLGIB.
