A synthetic technology for the production of methyl-ethyl-ketone (MEK) is introduced, which makes use of butylene catalytic hydration to produce secondary butanol (SBA) and this is followed by dehydrogenation of SBA. ...A synthetic technology for the production of methyl-ethyl-ketone (MEK) is introduced, which makes use of butylene catalytic hydration to produce secondary butanol (SBA) and this is followed by dehydrogenation of SBA. By optimizing the operating conditions of a commercial unit, the running results showed that the recom-mended process was successful and that the catalysts had high activity, good selectivity, and long lifespan, which ensured long-term running in commercial units.展开更多
N-component Bariev model for correlated hopping under open boundary conditions in one dimension is studied in the framework of Bethe ansatz method. The energy spectrum and the related Bethe ansatz equations are obtained.
The scheme and construction measurement of reinforcement and blocking against water for winder chamber after destroyed by mining influence have been introduced in this paper. The basic principle and advantages of bolt...The scheme and construction measurement of reinforcement and blocking against water for winder chamber after destroyed by mining influence have been introduced in this paper. The basic principle and advantages of bolting and grouting lining have been also listed. Bolting and grouting lining can increase the integrity and load-carrying capacity of supporting framework and it can assure the stability of supporting framework. It possesses not only the flexible and yielding capacity of bolting and shotcrete lining, but also the effect of rigid support such as metal support and brickwork, forming many kinds of support system, maintaining the stability of roadway together.展开更多
AIM： To retrospectively investigate the effect and safety of various new type precut sphincterotomy techniques （VNTPST） in endoscopic retrograde cholangiopancreatography （ERCP） due to difficult biliary duct cannu...AIM： To retrospectively investigate the effect and safety of various new type precut sphincterotomy techniques （VNTPST） in endoscopic retrograde cholangiopancreatography （ERCP） due to difficult biliary duct cannulation （DBC）. METHODS： A plough-like pull-type sphincterotome （PLPTS） or improved short nose sphincterotome or improved needle knife was applied. VNTPST was carried out in 30 of 280 patients, whose biliary tract could not be exposed well or deep cannulation was difficult to perform during ERCP with traditional methods. Patients were followed up for short-term complications and the therapeutic effect of VNTPS was observed and compared with that of traditional endoscopic sphincterotomy （EST）. RESULTS： A total 280 patients underwent ERCP, of which 3 failed in operation because of pathological features in stomch or duodenum, 247 successfully underwent traditional ERCP （89.1%, 247/277）, 30 failed （10.8%, 30/277）. VNTPS technique succeeded in 24 （80%, 24/30） of 30 cases. The successful rate of deep biliary duct cannulation increased 8.6% （24/277）, the total cannulation successful rate following precut was 97.7%. There was a significant difference between the two groups （97.7% vs 89.1%, x^2= 17.1, P 〈 0.01）. The incidence of complications was 9.3% （26/277） for traditional ERCP group and 13.3% （4/30） for VNTPS technique group. Guideline tip was broken in pancreatic duct （KPDGP） of one patient, and there was no pancreatitis, slight or moderate bleeding postoperatively occurred in 2 patients, 1 patient had bleeding during operation （PDWN）. There were no differences between VNTPS technique group and traditional ERCP（TRERCP）group （13.3% vs 9.3%, %2 = 0.478, P 〉 0.05）. CONCLUSION： VNTPS procedure and Deng＇s precut are highly effective methods to get biliary access during ERCP with DBC. With skillful techniques, it can increase the successful rate for deep cannulation of biliary duct and decrease complications. VNTPS technique, especially Deng＇s precut is as effective and safe as EST. This technique can be well performed in hospitals without particular equipments.展开更多
The Shenbei mining area in China contains typical soft rock from the Tertiary Period. As mining depths increase, deep soft rock roadways are damaged by large deformations and constantly need to be repaired to meet saf...The Shenbei mining area in China contains typical soft rock from the Tertiary Period. As mining depths increase, deep soft rock roadways are damaged by large deformations and constantly need to be repaired to meet safety requirements, which is a great security risk. In this study, the characteristics of deformation and failure of typical roadway were analyzed, and the fundamental reason for the roadway deformation was that traditional support methods and materials cannot control the large deformation of deep soft rock. Deep soft rock support technology was developed based on constant resistance energy absorption using constant resistance large deformation bolts. The correlative deformation mechanisms of surrounding rock and bolt were analyzed to understand the principle of constant resistance energy absorption. The new technology works well on-site and provides a new method for the excavation of roadwavs in Tertiary deed soft rock.展开更多
文摘A synthetic technology for the production of methyl-ethyl-ketone (MEK) is introduced, which makes use of butylene catalytic hydration to produce secondary butanol (SBA) and this is followed by dehydrogenation of SBA. By optimizing the operating conditions of a commercial unit, the running results showed that the recom-mended process was successful and that the catalysts had high activity, good selectivity, and long lifespan, which ensured long-term running in commercial units.
文摘N-component Bariev model for correlated hopping under open boundary conditions in one dimension is studied in the framework of Bethe ansatz method. The energy spectrum and the related Bethe ansatz equations are obtained.
文摘The scheme and construction measurement of reinforcement and blocking against water for winder chamber after destroyed by mining influence have been introduced in this paper. The basic principle and advantages of bolting and grouting lining have been also listed. Bolting and grouting lining can increase the integrity and load-carrying capacity of supporting framework and it can assure the stability of supporting framework. It possesses not only the flexible and yielding capacity of bolting and shotcrete lining, but also the effect of rigid support such as metal support and brickwork, forming many kinds of support system, maintaining the stability of roadway together.
文摘AIM： To retrospectively investigate the effect and safety of various new type precut sphincterotomy techniques （VNTPST） in endoscopic retrograde cholangiopancreatography （ERCP） due to difficult biliary duct cannulation （DBC）. METHODS： A plough-like pull-type sphincterotome （PLPTS） or improved short nose sphincterotome or improved needle knife was applied. VNTPST was carried out in 30 of 280 patients, whose biliary tract could not be exposed well or deep cannulation was difficult to perform during ERCP with traditional methods. Patients were followed up for short-term complications and the therapeutic effect of VNTPS was observed and compared with that of traditional endoscopic sphincterotomy （EST）. RESULTS： A total 280 patients underwent ERCP, of which 3 failed in operation because of pathological features in stomch or duodenum, 247 successfully underwent traditional ERCP （89.1%, 247/277）, 30 failed （10.8%, 30/277）. VNTPS technique succeeded in 24 （80%, 24/30） of 30 cases. The successful rate of deep biliary duct cannulation increased 8.6% （24/277）, the total cannulation successful rate following precut was 97.7%. There was a significant difference between the two groups （97.7% vs 89.1%, x^2= 17.1, P 〈 0.01）. The incidence of complications was 9.3% （26/277） for traditional ERCP group and 13.3% （4/30） for VNTPS technique group. Guideline tip was broken in pancreatic duct （KPDGP） of one patient, and there was no pancreatitis, slight or moderate bleeding postoperatively occurred in 2 patients, 1 patient had bleeding during operation （PDWN）. There were no differences between VNTPS technique group and traditional ERCP（TRERCP）group （13.3% vs 9.3%, %2 = 0.478, P 〉 0.05）. CONCLUSION： VNTPS procedure and Deng＇s precut are highly effective methods to get biliary access during ERCP with DBC. With skillful techniques, it can increase the successful rate for deep cannulation of biliary duct and decrease complications. VNTPS technique, especially Deng＇s precut is as effective and safe as EST. This technique can be well performed in hospitals without particular equipments.
基金supported by the Program of the National Natural Science Foundation of China (No. 51374214)National Science Foundation of China (No. 41040027)Fundamental Research Funds for the Central Universities (No. 2009QL06)
文摘The Shenbei mining area in China contains typical soft rock from the Tertiary Period. As mining depths increase, deep soft rock roadways are damaged by large deformations and constantly need to be repaired to meet safety requirements, which is a great security risk. In this study, the characteristics of deformation and failure of typical roadway were analyzed, and the fundamental reason for the roadway deformation was that traditional support methods and materials cannot control the large deformation of deep soft rock. Deep soft rock support technology was developed based on constant resistance energy absorption using constant resistance large deformation bolts. The correlative deformation mechanisms of surrounding rock and bolt were analyzed to understand the principle of constant resistance energy absorption. The new technology works well on-site and provides a new method for the excavation of roadwavs in Tertiary deed soft rock.
