This paper briefs the configuration and performance of large size gas turbines and their composed combined cycle power plants designed and produced by four large renown gas turbine manufacturing firms in the world, pr...This paper briefs the configuration and performance of large size gas turbines and their composed combined cycle power plants designed and produced by four large renown gas turbine manufacturing firms in the world, providing reference for the relevant sectors and enterprises in importing advanced gas turbines and technologies.展开更多
Using the data of conductivity-temperature-depth （CTD） intensive observations conducted during Oct-Nov. 2005, this study provides the first three-dimension quasi-synoptic description of the circulation in the wester...Using the data of conductivity-temperature-depth （CTD） intensive observations conducted during Oct-Nov. 2005, this study provides the first three-dimension quasi-synoptic description of the circulation in the western North Pacific. Several novel phenomena are revealed, especially in the deep ocean where earlier observations were very sparse. During the observations, the North Equatorial Current （NEC） splits at about 12°N near the sea surface. This bifurcation shifts northward with depth, reaching about 20°N at 1 000 m, and then remains nearly unchanged to as deep as 2 000 m. The Luzon Undercurrent （LUC）, emerging below the Kuroshio from about 21°N, intensifies southward, with its upper boundary surfacing around 12°N. From there, part of the LUC separates from the coast, while the rest continues southward to join the Mindanao Current （MC）. The MC extends to 2 000 m near the coast, and appears to be closely related to the subsurface cyclonic eddies which overlap low-salinity water from the North Pacific. The Mindanao Undercurrent （MUC）, carrying waters from the South Pacific, shifts eastward upon approaching the Mindanao coast and eventually becomes part of the eastward undercurrent between 10°N and 12°N at 130°E. In the upper 2 000 dbar, the total westward transport across 130°E between 7.5°N and 18°N reaches 65.4 Sv （1 Sv = 10-6 m3s^-1）, the northward transport across 18°N from Luzon coast to 130°E is up to 35.0 Sv, and the southward transport across 7.5°N from Mindanao coast to 130°E is 27.9 Sv.展开更多
Recent advances in understanding of pancreatitis and advances in technology have uncovered the veils of idiopathic pancreatitis to a point where a thorough history and judicious use of diagnostic techniques elucidate ...Recent advances in understanding of pancreatitis and advances in technology have uncovered the veils of idiopathic pancreatitis to a point where a thorough history and judicious use of diagnostic techniques elucidate the cause in over 80% of cases. This review examines the multitude of etiologies of what were once labeled idiopathic pancreatitis and provides the current evidence on each. This review begins with a background review of the current epidemiology of idiopathic pancreatitis prior to discussion of various etiologies. Etiologies of medications,infections,toxins,autoimmune disorders,vascular causes,and anatomic and functional causes are explored in detail. We conclude with management of true idiopathic pancreatitis and a summary of the various etiologic agents. Throughout this review,areas of controversies are highlighted.展开更多
With the aim of the harmonious development of economy-environment system in Tianjin Municipality, an index system used to evaluate the circular economy （CE） is presented in this paper. The index system consists of t...With the aim of the harmonious development of economy-environment system in Tianjin Municipality, an index system used to evaluate the circular economy （CE） is presented in this paper. The index system consists of the index of economy development, green development, human and culture development. According to the evaluation results, this paper brings forward the countermeasures including industry structure adjustment, improving city infrastructure system, increasing the level of habitation environment, establishing the system of green social consumption to improve the development of circular economy in Tianjin.展开更多
Spatial and temporal distribution characteristics and scale range of two significant areas were obtained by analyzing the relationship among summer rainfall in Yunnan province, height field and SST field (40°S –...Spatial and temporal distribution characteristics and scale range of two significant areas were obtained by analyzing the relationship among summer rainfall in Yunnan province, height field and SST field (40°S – 40°N, 30 °E – 70°W) across the North Hemisphere at 200 hPa, 500 hPa and 850 hPa for Jan. to May and correlation, and field wave structure. Remote key regions among summer rainfall in Yunnan province, height field and SST field (40°S – 40°N, 30°E – 70°W) across the North Hemisphere at 200 hPa, 500 hPa and 850 hPa were studied through further analyzing of the circulation system and its climate / weather significance. The result shows that the forecast has dependable physical basis when height and SST fields were viewed as predictors and physical models of impacts on rainy season precipitation in Yunnan are preliminarily concluded.展开更多
Propulsion of liquefied natural gas (LNG) ships is undergoing significant change. The traditional steam plant is losing favor because of its low cycle efficiency. Medium-speed diesel-electric and slow-speed diesel-mec...Propulsion of liquefied natural gas (LNG) ships is undergoing significant change. The traditional steam plant is losing favor because of its low cycle efficiency. Medium-speed diesel-electric and slow-speed diesel-mechanical drive ships are in service, and more are being built. Another attractive alternative is combined gas and steam turbine (COGAS) drive. This approach offers significant advantages over steam and diesel propulsion. This paper presents the case for the COGAS cycle.展开更多
The research status on the development of RBCC engines and corresponding aerospace vehicles around the world was overviewed,and the technical and application characteristics of RBCC technology were summarized.New deve...The research status on the development of RBCC engines and corresponding aerospace vehicles around the world was overviewed,and the technical and application characteristics of RBCC technology were summarized.New development trends of combined cycle engines as well as space transportation were analyzed,and lastly,some suggestions on the development of RBCC and the relative aerospace vehicles were proposed.展开更多
The paper deals with the comparative analysis of the performance of cooling and heating systems operating with NH3 （ammonia） or CO2 （carbon dioxide）, both natural refrigerants. The study is based on the exergetic ...The paper deals with the comparative analysis of the performance of cooling and heating systems operating with NH3 （ammonia） or CO2 （carbon dioxide）, both natural refrigerants. The study is based on the exergetic analysis that points out the location and the magnitude of a system malfunction. Both systems, with NH3 or CO2 operate in two stages. The exergetic analysis gives the direction of the structural optimization. The exergetic analysis has shown that the best structural schematic is not the same for the two agents. The exergetic analysis points out that the largest exergy destruction in the CO2 cycle is due to the throttling process and offers solutions to diminish it.展开更多
The effect of thermal cycling treatment on mechanical properties and thermal stability of a Zr41Ti14Cu12.5Ni10Be22.5 bulk metallic glass is investigated.The metallic glassy samples are sealed into quartz tubes under h...The effect of thermal cycling treatment on mechanical properties and thermal stability of a Zr41Ti14Cu12.5Ni10Be22.5 bulk metallic glass is investigated.The metallic glassy samples are sealed into quartz tubes under high vacuum condition,and liquid nitrogen together with electric furnace are used to control a periodical temperature variation between 196℃ and 150℃.The structure and properties of the tested samples for different thermal cycles have been examined by X-ray diffraction analysis,mechanical properties measurement and thermal analysis.It has been found that the structure and properties of the samples do not show a significant change even after 200 cycles,which suggests Zr41Ti14Cu12.5Ni10Be22.5 alloy as having potential in aerospace environment.展开更多
Objective To investigate the clinical outcomes of children with congenital heart disease （CHD） requiring extracorporeal membrane oxygenation （ECMO） and left ventricular assist device （LVAD） support after cardiac...Objective To investigate the clinical outcomes of children with congenital heart disease （CHD） requiring extracorporeal membrane oxygenation （ECMO） and left ventricular assist device （LVAD） support after cardiac surgery. Methods A total of 22 patients with CHD who required postcardiotomy mechanical circulatory support between March 2004 and March 2011 （85 months ） were analyzed retrospectively. Median age of the patients was 420 d （ 15 d - 4 years） and median weight was 3.4 kg （ 2 - 14. 5 kg ）. Eight patients were put on ECMO, while 14 patients were placed on LVAD. Results Thirteen （59%） patients died and 9 （41% ） survived to discharge. In survivals, the duration of LVAD and the duration of ECMO were both shorter than those of nonsurvivals （P 〈 O. 05）. The main complication was bleeding. Conclusion The earlier treatment and application of more advanced cardiac support devices for CHD patients are key factors for reducing complications.展开更多
The cycle length distribution of a graph G of order n is a sequence （c1 （G）,…, cn （G））, where ci （G） is the number of cycles of length i in G. In general, the graphs with cycle length distribution （c1（G） ,...The cycle length distribution of a graph G of order n is a sequence （c1 （G）,…, cn （G））, where ci （G） is the number of cycles of length i in G. In general, the graphs with cycle length distribution （c1（G） ,…,cn（G）） are not unique. A graph G is determined by its cycle length distribution if the graph with cycle length distribution （c1 （G）,…, cn （G）） is unique. Let Kn,n＋r be a complete bipartite graph and A lohtaib in E（Kn,n＋r）. In this paper, we obtain： Let s 〉 1 be an integer. （1） If r = 2s, n 〉 s（s - 1） ＋ 2｜A｜, then Kn,n＋r - A （A lohtain in E（Kn,n＋r）,｜A｜ ≤ 3） is determined by its cycle length distribution; （2） If r = 2s ＋ 1,n 〉 s^2 ＋ 2｜A｜, Kn,n＋r - A （A lohtain in E（Kn,n＋r）, ｜A｜ ≤3） is determined by its cycle length distribution.展开更多
文摘This paper briefs the configuration and performance of large size gas turbines and their composed combined cycle power plants designed and produced by four large renown gas turbine manufacturing firms in the world, providing reference for the relevant sectors and enterprises in importing advanced gas turbines and technologies.
基金Supported by National Natural Science Foundation of China (Nos,40890153 and 40576016)
文摘Using the data of conductivity-temperature-depth （CTD） intensive observations conducted during Oct-Nov. 2005, this study provides the first three-dimension quasi-synoptic description of the circulation in the western North Pacific. Several novel phenomena are revealed, especially in the deep ocean where earlier observations were very sparse. During the observations, the North Equatorial Current （NEC） splits at about 12°N near the sea surface. This bifurcation shifts northward with depth, reaching about 20°N at 1 000 m, and then remains nearly unchanged to as deep as 2 000 m. The Luzon Undercurrent （LUC）, emerging below the Kuroshio from about 21°N, intensifies southward, with its upper boundary surfacing around 12°N. From there, part of the LUC separates from the coast, while the rest continues southward to join the Mindanao Current （MC）. The MC extends to 2 000 m near the coast, and appears to be closely related to the subsurface cyclonic eddies which overlap low-salinity water from the North Pacific. The Mindanao Undercurrent （MUC）, carrying waters from the South Pacific, shifts eastward upon approaching the Mindanao coast and eventually becomes part of the eastward undercurrent between 10°N and 12°N at 130°E. In the upper 2 000 dbar, the total westward transport across 130°E between 7.5°N and 18°N reaches 65.4 Sv （1 Sv = 10-6 m3s^-1）, the northward transport across 18°N from Luzon coast to 130°E is up to 35.0 Sv, and the southward transport across 7.5°N from Mindanao coast to 130°E is 27.9 Sv.
文摘Recent advances in understanding of pancreatitis and advances in technology have uncovered the veils of idiopathic pancreatitis to a point where a thorough history and judicious use of diagnostic techniques elucidate the cause in over 80% of cases. This review examines the multitude of etiologies of what were once labeled idiopathic pancreatitis and provides the current evidence on each. This review begins with a background review of the current epidemiology of idiopathic pancreatitis prior to discussion of various etiologies. Etiologies of medications,infections,toxins,autoimmune disorders,vascular causes,and anatomic and functional causes are explored in detail. We conclude with management of true idiopathic pancreatitis and a summary of the various etiologic agents. Throughout this review,areas of controversies are highlighted.
文摘With the aim of the harmonious development of economy-environment system in Tianjin Municipality, an index system used to evaluate the circular economy （CE） is presented in this paper. The index system consists of the index of economy development, green development, human and culture development. According to the evaluation results, this paper brings forward the countermeasures including industry structure adjustment, improving city infrastructure system, increasing the level of habitation environment, establishing the system of green social consumption to improve the development of circular economy in Tianjin.
基金Key Foundation Project of Yunnan Province (2003D0014Z)Natural Science Foundation ofChina (40065001)
文摘Spatial and temporal distribution characteristics and scale range of two significant areas were obtained by analyzing the relationship among summer rainfall in Yunnan province, height field and SST field (40°S – 40°N, 30 °E – 70°W) across the North Hemisphere at 200 hPa, 500 hPa and 850 hPa for Jan. to May and correlation, and field wave structure. Remote key regions among summer rainfall in Yunnan province, height field and SST field (40°S – 40°N, 30°E – 70°W) across the North Hemisphere at 200 hPa, 500 hPa and 850 hPa were studied through further analyzing of the circulation system and its climate / weather significance. The result shows that the forecast has dependable physical basis when height and SST fields were viewed as predictors and physical models of impacts on rainy season precipitation in Yunnan are preliminarily concluded.
文摘Propulsion of liquefied natural gas (LNG) ships is undergoing significant change. The traditional steam plant is losing favor because of its low cycle efficiency. Medium-speed diesel-electric and slow-speed diesel-mechanical drive ships are in service, and more are being built. Another attractive alternative is combined gas and steam turbine (COGAS) drive. This approach offers significant advantages over steam and diesel propulsion. This paper presents the case for the COGAS cycle.
文摘The research status on the development of RBCC engines and corresponding aerospace vehicles around the world was overviewed,and the technical and application characteristics of RBCC technology were summarized.New development trends of combined cycle engines as well as space transportation were analyzed,and lastly,some suggestions on the development of RBCC and the relative aerospace vehicles were proposed.
文摘The paper deals with the comparative analysis of the performance of cooling and heating systems operating with NH3 （ammonia） or CO2 （carbon dioxide）, both natural refrigerants. The study is based on the exergetic analysis that points out the location and the magnitude of a system malfunction. Both systems, with NH3 or CO2 operate in two stages. The exergetic analysis gives the direction of the structural optimization. The exergetic analysis has shown that the best structural schematic is not the same for the two agents. The exergetic analysis points out that the largest exergy destruction in the CO2 cycle is due to the throttling process and offers solutions to diminish it.
基金supported by the National Basic Research Program of China(Grant No.2007CB613905)the National Natural Science Foundation of China(Grant Nos.50971073,51101090 and 51271095)Beijing Natural Science Foundation(Effect of pre-cyclic loading on mechanical behaviors of bulk amorphous alloys)
文摘The effect of thermal cycling treatment on mechanical properties and thermal stability of a Zr41Ti14Cu12.5Ni10Be22.5 bulk metallic glass is investigated.The metallic glassy samples are sealed into quartz tubes under high vacuum condition,and liquid nitrogen together with electric furnace are used to control a periodical temperature variation between 196℃ and 150℃.The structure and properties of the tested samples for different thermal cycles have been examined by X-ray diffraction analysis,mechanical properties measurement and thermal analysis.It has been found that the structure and properties of the samples do not show a significant change even after 200 cycles,which suggests Zr41Ti14Cu12.5Ni10Be22.5 alloy as having potential in aerospace environment.
文摘Objective To investigate the clinical outcomes of children with congenital heart disease （CHD） requiring extracorporeal membrane oxygenation （ECMO） and left ventricular assist device （LVAD） support after cardiac surgery. Methods A total of 22 patients with CHD who required postcardiotomy mechanical circulatory support between March 2004 and March 2011 （85 months ） were analyzed retrospectively. Median age of the patients was 420 d （ 15 d - 4 years） and median weight was 3.4 kg （ 2 - 14. 5 kg ）. Eight patients were put on ECMO, while 14 patients were placed on LVAD. Results Thirteen （59%） patients died and 9 （41% ） survived to discharge. In survivals, the duration of LVAD and the duration of ECMO were both shorter than those of nonsurvivals （P 〈 O. 05）. The main complication was bleeding. Conclusion The earlier treatment and application of more advanced cardiac support devices for CHD patients are key factors for reducing complications.
基金the National Natural Science Foundation of China(Nos.1070106810671191)
文摘The cycle length distribution of a graph G of order n is a sequence （c1 （G）,…, cn （G））, where ci （G） is the number of cycles of length i in G. In general, the graphs with cycle length distribution （c1（G） ,…,cn（G）） are not unique. A graph G is determined by its cycle length distribution if the graph with cycle length distribution （c1 （G）,…, cn （G）） is unique. Let Kn,n＋r be a complete bipartite graph and A lohtaib in E（Kn,n＋r）. In this paper, we obtain： Let s 〉 1 be an integer. （1） If r = 2s, n 〉 s（s - 1） ＋ 2｜A｜, then Kn,n＋r - A （A lohtain in E（Kn,n＋r）,｜A｜ ≤ 3） is determined by its cycle length distribution; （2） If r = 2s ＋ 1,n 〉 s^2 ＋ 2｜A｜, Kn,n＋r - A （A lohtain in E（Kn,n＋r）, ｜A｜ ≤3） is determined by its cycle length distribution.
