[Objective] The aim of this study was to evaluate the economic loss caused by Zhouqu debris flow. [Method] After the large debris flows happened on August 7, 2010 in Zhouqu, Gansu Province, we collected data at the fi...[Objective] The aim of this study was to evaluate the economic loss caused by Zhouqu debris flow. [Method] After the large debris flows happened on August 7, 2010 in Zhouqu, Gansu Province, we collected data at the first time after the disaster, and then built an assessment model to estimate the potential economic losses. [Result] The total loss reached 16.57×10^2 million Yuan, in which indirect economic loss was up to 2.42×10^2 million yaun while the actual direct economic loss was around 14.15×10^2 million Yuan. [Conclusion] The proportional coefficient method is a rapid and efficient method for evaluating the indirect loss caused by disasters.展开更多
AIM： To compare small sphincterotomy combined with endoscopic papillary large balloon dilation （SES ＋ ELBD） and endoscopic sphincterotomy （EST） for large bile duct stones. METHODS： We compared prospectively SES...AIM： To compare small sphincterotomy combined with endoscopic papillary large balloon dilation （SES ＋ ELBD） and endoscopic sphincterotomy （EST） for large bile duct stones. METHODS： We compared prospectively SES ＋ ELBD （group A, n = 27） with conventional EST （group B, n = 28） for the treatment of large bile duct stones （≥ 15 mm）. When the stone could not be removed with a normal basket, mechanical lithotripsy was performed. We compared the rates of complete stone removal with one session and application of mechanical lithotripsy. RESULTS： No significant differences were observed in the mean largest stone size （A： 20.8 mm, B： 21.3 mm）, bile duct diameter （A： 21.4 turn, B： 20.5 ram）, number of stones （A： 2.2, B： 2.3）, or procedure time （A： 18 min, B： 19 rain） between the two groups. The rates of complete stone removal with one session was 85% in group A and 86% in group B （P = 0.473）. Mechanical lithotripsy was required for stone removal in nine of 27 patients （33%） in group A and nine of 28 patients （32%, P = 0.527） in group B.CONCLUSION： SES ＋ ELBD did not show significant benefits compared to conventional EST, especially for the removal of large （≥ 15 mm） bile duct stones.展开更多
A new method was proposed to cope with the earth slope reliability problem under seismic loadings. The algorithm integrates the concepts of artificial neural network, the first order second moment reliability method a...A new method was proposed to cope with the earth slope reliability problem under seismic loadings. The algorithm integrates the concepts of artificial neural network, the first order second moment reliability method and the deterministic stability analysis method of earth slope. The performance function and its derivatives in slope stability analysis under seismic loadings were approximated by a trained multi-layer feed-forward neural network with differentiable transfer functions. The statistical moments calculated from the performance function values and the corresponding gradients using neural network were then used in the first order second moment method for the calculation of the reliability index in slope safety analysis. Two earth slope examples were presented for illustrating the applicability of the proposed approach. The new method is effective in slope reliability analysis. And it has potential application to other reliability problems of complicated engineering structure with a considerably large number of random variables.展开更多
The ratio of Fe-Al compound at the bonding interface of solid steel plate to Al-7graphite slurry was used to characterize the interracial structure of steel-Al-7graphite semi-solid bonding plate quantitatively. The re...The ratio of Fe-Al compound at the bonding interface of solid steel plate to Al-7graphite slurry was used to characterize the interracial structure of steel-Al-7graphite semi-solid bonding plate quantitatively. The relationship between the ratio of Fe-Al compound at interface and bonding parameters （such as preheat temperature of steel plate, solid fraction of Al-7graphite slurry and rolling speed） was established by artificial neural networks perfectly. The results show that when the bonding parameters are 516 ℃ for preheat temperature of steel plate, 32.5% for solid fraction of Al-7graphite slurry and 12 mm/s for rolling speed, the reasonable ratio of Fe-Al compound corresponding to the largest interfacial shear strength of bonding plate is obtained to be 70.1%. This reasonable ratio of Fe-Al compound is a quantitative criterion of interracial embrittlement, namely, when the ratio of Fe-Al compound at interface is larger than 70.1%, interfacial embrittlement will occur.展开更多
Petrochemicals play a vital role in the economy of any nation. The products of the industry are the building blocks in many industries as they deepen the forward and backward linkages of the petroleum sector with the ...Petrochemicals play a vital role in the economy of any nation. The products of the industry are the building blocks in many industries as they deepen the forward and backward linkages of the petroleum sector with the rest of the economy. The industry uses a variety of hydrocarbon feedstock such as different cuts of naphtha from refinery and natural gas. One of the problems facing the industry is lack of reliable feedstock supplies. Nigeria has the potential to be a major petrochemicals producer. With proven gas reserves currently estimated at 187 tcf, not much has been accomplished with respect to the effective exploitation and utilization of this resource as most of the nation＇s natural gas production has been flared, liquefied for export or re-injected to enhance greater crude oil recovery. It has become imperative to further find ways to exploit and utilize the nation＇s natural gas reserves and translate it to the improvement of the nation＇s economy. Steam reforming of natural gas is one of the avenues for conversion of natural gas to petrochemicals. This paper, however, reviews various ways of utilizing natural gas, examines the process details of steam reforming of natural gas as a route to optimized natural gas utilization and industrialization in Nigeria. Syngas （synthesis gas） is a versatile feedstock for most petrochemicals and chemical intermediates. Thus utilizing natural gas in this way would strengthen the petrochemical industry making it possible for the country to change from raw materials to value-added products supplier, boost the economy and solve the ＂hydra-headed＂ problem of unemployment in Nigeria with its multiplier employment effect.展开更多
In efforts to overcome an foreseeable energy crisis predicated on limited oil and gas supplies, reserves; economic variations facing the world, and of course the environmental side effects of fossil fuels, an urgent n...In efforts to overcome an foreseeable energy crisis predicated on limited oil and gas supplies, reserves; economic variations facing the world, and of course the environmental side effects of fossil fuels, an urgent need for energy sources that provide sustainable, safe and economic supplies for the world is imperative. The current fossil fuel energy system must be improved to ensure a better and cleaner transportation future for the world. Despite the fact that the marine transportation sector consumes only 5% of global petroleum production; it is responsible for 15% of the world NOx and SOx emissions. These figures must be the engine that powers the scientific research worldwide to develop new solutions for a very old energy problem. In this paper, the most effective types of marine power plants were discussed. The history of the development of each type was presented first and the technical aspects were discussed second. Also, the fuel ceils as a new type of power plants used in marine sector were briefed to give a complete overview of the past, present and future of the marine power plants development. Based on the increased worldwide concerns regarding harmful emissions, many researchers have introduced solutions to this problem, including the adoption of new cleaner fuels. This paper was guided using the same trend and by implementing the hydrogen as fuel for marine internal combustion engine, gas turbines, and fuel cells.展开更多
The back propagation (BP)-based artificial neural nets (ANN) can identify complicated relationships among dissolved gas contents in transformer oil and corresponding fault types, using the highly nonlinear mapping nat...The back propagation (BP)-based artificial neural nets (ANN) can identify complicated relationships among dissolved gas contents in transformer oil and corresponding fault types, using the highly nonlinear mapping nature of the neural nets. An efficient BP-ALM (BP with Adaptive Learning Rate and Momentum coefficient) algorithm is proposed to reduce the training time and avoid being trapped into local minima, where the learning rate and the momentum coefficient are altered at iterations. We developed a system of transformer fault diagnosis based on Dissolved Gases Analysis (DGA) with a BP-ALM algorithm. Training patterns were selected from the results of a Refined Three-Ratio method (RTR). Test results show that the system has a better ability of quick learning and global convergence than other methods and a superior performance in fault diagnosis compared to convectional BP-based neural networks and RTR.展开更多
The recent growth of the global petroleum refining industry and the main technologies and measures for China to process inferior crude oil were introduced. The main technologies and measures include the control over e...The recent growth of the global petroleum refining industry and the main technologies and measures for China to process inferior crude oil were introduced. The main technologies and measures include the control over equipment corrosion induced by sour and acidic crude, in particular the corrosion of atmospheric and vacuum distillation units, the development of technology for processing inferior residue, and the development of desulfurization technology and sulfur recovery technology in the course of processing of petroleum products. In order to meet the needs for national economic development, China’s refining enterprises will uninterruptedly develop and prefect technologies for processing inferior crude, enhance the process and equipment management, sum up the experience for better processing of inferior crude, so as to provide high-quality oil products and petrochemical feedstocks to public with better economic return.展开更多
Biloma is an encapsulated bile collection outside the biliary tree due to a bile leak. It is occasionally found following traumatic liver injury or iatrogenic injury to the biliary tract, induced either during an endo...Biloma is an encapsulated bile collection outside the biliary tree due to a bile leak. It is occasionally found following traumatic liver injury or iatrogenic injury to the biliary tract, induced either during an endoscopic or surgical procedure. It is a rare complication of transcatheter arterial embolization (TAE). Although biloma can be shrunk by appropriate aspiration or drainage in majority of cases,we report a case of intrahepatic biloma following repeated TAE for hepatocellular carcinoma (HCC) and complicated by infection and intrahepatic stones. This particular constellation of problems has not been reported before and the intrahepatic stones need to be removed by percutaneous procedure.展开更多
AIM： To clarify the innervation of human gallbladder,with special reference to morphological understanding of gallstone formation after gastrectomy.METHODS： The liver, gallbladder and surrounding structures were imm...AIM： To clarify the innervation of human gallbladder,with special reference to morphological understanding of gallstone formation after gastrectomy.METHODS： The liver, gallbladder and surrounding structures were immersed in a 10 mg/L solution of alizarin red S in ethanol to stain the peripheral nerves in cadavers （n = 10）. Innervation in the areas was completely dissected under a binocular microscope. Similarly,innervation in the same areas of 10 Suncus murinus （S. murinus） was examined employing whole mount immunohistochemistry.RESULTS： Innervation of the gallbladder occurred predominantly through two routes. One was from the anterior hepatic plexus, the innervation occurred along the cystic arteries and duct. Invariably this route passed through the hepatoduodenal ligament. The other route was from the posterior hepatic plexus, the innervation occurred along the cystic duct ventrally. This route also passed through the hepatoduodenal ligament dorsally.Similar results were obtained in S. murinus.CONCLUSION： The route from the anterior hepatic plexus via the cystic artery and/or duct is crucial for preserving gallbladder innervation. Lymph node dissection specifically in the hepatoduodenal ligament may affect the incidence of gallstones after gastrectomy.Furthermore, the route from the posterior hepatic plexus via the common bile duct and the cystic duct to the gallbladder should not be disregarded. Preservation of the plexus may attenuate the incidence of gallstone formation after gastrectomy.展开更多
基金Supported by National Key Technology Research and Development Program(2008BAK50B06)~~
文摘[Objective] The aim of this study was to evaluate the economic loss caused by Zhouqu debris flow. [Method] After the large debris flows happened on August 7, 2010 in Zhouqu, Gansu Province, we collected data at the first time after the disaster, and then built an assessment model to estimate the potential economic losses. [Result] The total loss reached 16.57×10^2 million Yuan, in which indirect economic loss was up to 2.42×10^2 million yaun while the actual direct economic loss was around 14.15×10^2 million Yuan. [Conclusion] The proportional coefficient method is a rapid and efficient method for evaluating the indirect loss caused by disasters.
文摘AIM： To compare small sphincterotomy combined with endoscopic papillary large balloon dilation （SES ＋ ELBD） and endoscopic sphincterotomy （EST） for large bile duct stones. METHODS： We compared prospectively SES ＋ ELBD （group A, n = 27） with conventional EST （group B, n = 28） for the treatment of large bile duct stones （≥ 15 mm）. When the stone could not be removed with a normal basket, mechanical lithotripsy was performed. We compared the rates of complete stone removal with one session and application of mechanical lithotripsy. RESULTS： No significant differences were observed in the mean largest stone size （A： 20.8 mm, B： 21.3 mm）, bile duct diameter （A： 21.4 turn, B： 20.5 ram）, number of stones （A： 2.2, B： 2.3）, or procedure time （A： 18 min, B： 19 rain） between the two groups. The rates of complete stone removal with one session was 85% in group A and 86% in group B （P = 0.473）. Mechanical lithotripsy was required for stone removal in nine of 27 patients （33%） in group A and nine of 28 patients （32%, P = 0.527） in group B.CONCLUSION： SES ＋ ELBD did not show significant benefits compared to conventional EST, especially for the removal of large （≥ 15 mm） bile duct stones.
文摘A new method was proposed to cope with the earth slope reliability problem under seismic loadings. The algorithm integrates the concepts of artificial neural network, the first order second moment reliability method and the deterministic stability analysis method of earth slope. The performance function and its derivatives in slope stability analysis under seismic loadings were approximated by a trained multi-layer feed-forward neural network with differentiable transfer functions. The statistical moments calculated from the performance function values and the corresponding gradients using neural network were then used in the first order second moment method for the calculation of the reliability index in slope safety analysis. Two earth slope examples were presented for illustrating the applicability of the proposed approach. The new method is effective in slope reliability analysis. And it has potential application to other reliability problems of complicated engineering structure with a considerably large number of random variables.
基金Project(50054) supported by the Program for New Century Excellent Talents in Universityproject(20060004020) supported by the Research Fund for the Doctoral Program of Higher Education+1 种基金project(3062017) supported by the Natural Science Foundation of Beijing, Chinaproject(2004SZ007) supported by the Foundation of Beijing Jiaotong University
文摘The ratio of Fe-Al compound at the bonding interface of solid steel plate to Al-7graphite slurry was used to characterize the interracial structure of steel-Al-7graphite semi-solid bonding plate quantitatively. The relationship between the ratio of Fe-Al compound at interface and bonding parameters （such as preheat temperature of steel plate, solid fraction of Al-7graphite slurry and rolling speed） was established by artificial neural networks perfectly. The results show that when the bonding parameters are 516 ℃ for preheat temperature of steel plate, 32.5% for solid fraction of Al-7graphite slurry and 12 mm/s for rolling speed, the reasonable ratio of Fe-Al compound corresponding to the largest interfacial shear strength of bonding plate is obtained to be 70.1%. This reasonable ratio of Fe-Al compound is a quantitative criterion of interracial embrittlement, namely, when the ratio of Fe-Al compound at interface is larger than 70.1%, interfacial embrittlement will occur.
文摘Petrochemicals play a vital role in the economy of any nation. The products of the industry are the building blocks in many industries as they deepen the forward and backward linkages of the petroleum sector with the rest of the economy. The industry uses a variety of hydrocarbon feedstock such as different cuts of naphtha from refinery and natural gas. One of the problems facing the industry is lack of reliable feedstock supplies. Nigeria has the potential to be a major petrochemicals producer. With proven gas reserves currently estimated at 187 tcf, not much has been accomplished with respect to the effective exploitation and utilization of this resource as most of the nation＇s natural gas production has been flared, liquefied for export or re-injected to enhance greater crude oil recovery. It has become imperative to further find ways to exploit and utilize the nation＇s natural gas reserves and translate it to the improvement of the nation＇s economy. Steam reforming of natural gas is one of the avenues for conversion of natural gas to petrochemicals. This paper, however, reviews various ways of utilizing natural gas, examines the process details of steam reforming of natural gas as a route to optimized natural gas utilization and industrialization in Nigeria. Syngas （synthesis gas） is a versatile feedstock for most petrochemicals and chemical intermediates. Thus utilizing natural gas in this way would strengthen the petrochemical industry making it possible for the country to change from raw materials to value-added products supplier, boost the economy and solve the ＂hydra-headed＂ problem of unemployment in Nigeria with its multiplier employment effect.
文摘In efforts to overcome an foreseeable energy crisis predicated on limited oil and gas supplies, reserves; economic variations facing the world, and of course the environmental side effects of fossil fuels, an urgent need for energy sources that provide sustainable, safe and economic supplies for the world is imperative. The current fossil fuel energy system must be improved to ensure a better and cleaner transportation future for the world. Despite the fact that the marine transportation sector consumes only 5% of global petroleum production; it is responsible for 15% of the world NOx and SOx emissions. These figures must be the engine that powers the scientific research worldwide to develop new solutions for a very old energy problem. In this paper, the most effective types of marine power plants were discussed. The history of the development of each type was presented first and the technical aspects were discussed second. Also, the fuel ceils as a new type of power plants used in marine sector were briefed to give a complete overview of the past, present and future of the marine power plants development. Based on the increased worldwide concerns regarding harmful emissions, many researchers have introduced solutions to this problem, including the adoption of new cleaner fuels. This paper was guided using the same trend and by implementing the hydrogen as fuel for marine internal combustion engine, gas turbines, and fuel cells.
文摘The back propagation (BP)-based artificial neural nets (ANN) can identify complicated relationships among dissolved gas contents in transformer oil and corresponding fault types, using the highly nonlinear mapping nature of the neural nets. An efficient BP-ALM (BP with Adaptive Learning Rate and Momentum coefficient) algorithm is proposed to reduce the training time and avoid being trapped into local minima, where the learning rate and the momentum coefficient are altered at iterations. We developed a system of transformer fault diagnosis based on Dissolved Gases Analysis (DGA) with a BP-ALM algorithm. Training patterns were selected from the results of a Refined Three-Ratio method (RTR). Test results show that the system has a better ability of quick learning and global convergence than other methods and a superior performance in fault diagnosis compared to convectional BP-based neural networks and RTR.
文摘The recent growth of the global petroleum refining industry and the main technologies and measures for China to process inferior crude oil were introduced. The main technologies and measures include the control over equipment corrosion induced by sour and acidic crude, in particular the corrosion of atmospheric and vacuum distillation units, the development of technology for processing inferior residue, and the development of desulfurization technology and sulfur recovery technology in the course of processing of petroleum products. In order to meet the needs for national economic development, China’s refining enterprises will uninterruptedly develop and prefect technologies for processing inferior crude, enhance the process and equipment management, sum up the experience for better processing of inferior crude, so as to provide high-quality oil products and petrochemical feedstocks to public with better economic return.
文摘Biloma is an encapsulated bile collection outside the biliary tree due to a bile leak. It is occasionally found following traumatic liver injury or iatrogenic injury to the biliary tract, induced either during an endoscopic or surgical procedure. It is a rare complication of transcatheter arterial embolization (TAE). Although biloma can be shrunk by appropriate aspiration or drainage in majority of cases,we report a case of intrahepatic biloma following repeated TAE for hepatocellular carcinoma (HCC) and complicated by infection and intrahepatic stones. This particular constellation of problems has not been reported before and the intrahepatic stones need to be removed by percutaneous procedure.
基金Supported by Ministry of Education, Culture, Sports, Science and Technology of Japan, Grant No. 16590139
文摘AIM： To clarify the innervation of human gallbladder,with special reference to morphological understanding of gallstone formation after gastrectomy.METHODS： The liver, gallbladder and surrounding structures were immersed in a 10 mg/L solution of alizarin red S in ethanol to stain the peripheral nerves in cadavers （n = 10）. Innervation in the areas was completely dissected under a binocular microscope. Similarly,innervation in the same areas of 10 Suncus murinus （S. murinus） was examined employing whole mount immunohistochemistry.RESULTS： Innervation of the gallbladder occurred predominantly through two routes. One was from the anterior hepatic plexus, the innervation occurred along the cystic arteries and duct. Invariably this route passed through the hepatoduodenal ligament. The other route was from the posterior hepatic plexus, the innervation occurred along the cystic duct ventrally. This route also passed through the hepatoduodenal ligament dorsally.Similar results were obtained in S. murinus.CONCLUSION： The route from the anterior hepatic plexus via the cystic artery and/or duct is crucial for preserving gallbladder innervation. Lymph node dissection specifically in the hepatoduodenal ligament may affect the incidence of gallstones after gastrectomy.Furthermore, the route from the posterior hepatic plexus via the common bile duct and the cystic duct to the gallbladder should not be disregarded. Preservation of the plexus may attenuate the incidence of gallstone formation after gastrectomy.
