In order to develop the warming bending technology of the large diameter thin-walled（LDTW） commercial pure titanium alloy CP-Ti tubes, the warm bending mechanism of the extrados and intrados of LDTW CP-Ti tubes was ...In order to develop the warming bending technology of the large diameter thin-walled（LDTW） commercial pure titanium alloy CP-Ti tubes, the warm bending mechanism of the extrados and intrados of LDTW CP-Ti tubes was researched. By EBSD analysis and Vickers hardness test, the changes of microstructure and strength of the tubes at different bending temperatures of 293, 423 and 573 K, were analyzed. The results show： 1） The extrados of the bent tube deforms mainly by slip, along with few twinning, and the preferred orientation is similar to that of the initial tube; the intrados of the bent tube experiences compression deformation mainly by {1 012} tensile twinning, and the twinning makes the preferred orientation of wall materials change sharply. 2） The Vickers hardness values of both the extrados and intrados of the samples after bending increase greatly; the Vickers hardness values of the intrados are much higher than those of the extrados, and Vickers hardness values of the RD-TD planes are always higher than those of the RD-LD planes, which are related to the different deformation mechanisms.展开更多
Hydrodynamic cavitaion venturi tube technique is used for pico and nano bubble generations in coal column flotation. In order to determine the optimal design of hydrodynamic cavitation venture tube for pico and nano b...Hydrodynamic cavitaion venturi tube technique is used for pico and nano bubble generations in coal column flotation. In order to determine the optimal design of hydrodynamic cavitation venture tube for pico and nano bubble generation, a four-factor three-level Central Composite Design of Experimental was conducted for investigating four important design parameters of cavitation venturi tube governing the median size and the volume of pico and nano bubbles. The test results showed that maximum volume of pico and nano bubbles, 65–75%, and minimum mean pico and nano bubble size,150–240 nm, were achieved at the medium ratio of the diameter of outlet of the venturi-tube and diameter of throat(3–4), medium outlet angle(11–13°), high inlet angle(26–27°) and high ratio of the length of the throat and the diameter of throat(2.3–3). Study the effects of the producing pico and nano bubbles on fine coal flotation was performed in a 5 cm diameter 260 cm height flotation column. The optimal percentage of pico and nano bubbles was about 70%, which produced maximum combustible material recovery of 86% with clean coal ash content of 11.7%.展开更多
A novel biological small-diameter vascular graft was evaluated in a canine model. 3 cm long segments with 4 mm I.D. were implanted end-to-end in the carotid position of 12 dogs for 6 months. Color Doppler sonography w...A novel biological small-diameter vascular graft was evaluated in a canine model. 3 cm long segments with 4 mm I.D. were implanted end-to-end in the carotid position of 12 dogs for 6 months. Color Doppler sonography was performed at the first week post-operation, and angiography was then administered to 9 grafts at 4th week, 12th week and 24th week respectively to monitor the graft pantency and blood flow characteristics. Vascular samples containing the grafts were collected at 1st week, 8th week, 12th week and 24th week after implantation. Morphological changes of the grafts were observed by optical and scanning electron microscopic (SEM) studies and compared with that of the original prosthesis and the normal host vessel. All grafts were patent throughout the experiment except one graft. Histopathology and SEM demonstrated both a nearly complete inner capsule of varied thickness lining the graft luminal surface and connective tissue adventitia formation at one-week post-operation. The neointima became confluent at 8 weeks and then compact but had no signs of hyperplasia up to 12 weeks; meanwhile on the neointimal surface newly grown endothelial-like cells were migrating from the stoma to the middle portion. The grafts also illustrated endothelialization in many “islands” in the mid-segment luminal surface of the grafts. In addition, the closer distance the cells towards the stoma were, the more morphological similarity the cells with the normal endothelial were. Taken together, the biological vascular graft remained patent for 24 weeks as a carotid prosthesis, characterized by the early and complete neointima formation plus endothelialization starting before 12 weeks post grafting. Therefore, the graft seems suitable for reconstruction of vascular lesions in dogs. Further studies may be carried out to extend the graft application for the clinical use.展开更多
AIM： to compare the feasibility and patients＇ tolerance of esophagogastroduodenoscopy （EGD） using a thin endoscope with those of conventional oral EGD and to determine the optimal route of introduction of smallcal...AIM： to compare the feasibility and patients＇ tolerance of esophagogastroduodenoscopy （EGD） using a thin endoscope with those of conventional oral EGD and to determine the optimal route of introduction of smallcaliber endoscopes. METHODS： One hundred and sixty outpatients referred for diagnostic EGD were randomly allocated to 3 groups： conventional （C）-EGD （9.8 mm in diameter）, transnasal （TN）-EGD and transoral （TO）-EGD （5.9 mm in diameter）. Pre-EGD anxiety was measured using a 100-mm visual analogue scale （VAS）. After EGD, patients and endoscopists completed a questionnaire on the pain, nausea, choking, overall discomfort, and quality of the examination either using VAS or answering some questions. The duration of EGD was timed. Blood oxygen saturation （SaO2） and heart rate （HR） were monitored during EGD. RESULTS： Twenty-one patients refused to participate in the study. The 3 groups were well-matched for age, gender, experience with EGD, and anxiety. EGD was completed in 91.1% （41/45）, 97.5% （40/41）, and 96.2% （51/53） of cases in TN-EGD, TO-EGD, and C-EGD groups, respectively. TN-EGD lasted longer （3.11 ± 1.60 min） than TO-EGD （2.25 ± 1.45 min） and C-EGD （2.49 ± 1.64 rain） （P 〈 0.05）. The overall tolerance was higher （P 〈 0.05） and the overall discomfort was lower （P 〈 0.05） in TN-EGD group than in C-EGD group. EGD was tolerated ＂better than expected＂ in 73.2% of patients in TN-EGD group and 55% and 39.2% of patients in TO-EGD and C-EGD groups, respectively （P 〈 0.05）. Endoscopy was tolerated ＂worst than expected＂ in 4.9% of patients in TN-EGD group and 17.5% and 23.5% of patients in TO- EGD and C-EGD groups, respectively （P 〈 0.05）. TN-EGD caused mild epistaxis in one case, The ability to insuffiate air, wash the lens, and suction of the thin endoscope were lower than those of conventional instrument （P 〈 0,001）, All biopsies performed were adequate for histological assessment. CONCLUSION： Diagnostic TN-EGD is better tolerated than C-EGD, Narrow-diameter endoscope has a level of diagnostic accuracy comparable to that of conventional gastroscope, even though some technical characteristics of these instruments should be improved, Transnasal EGD with narrow-diameter endoscope should be proposed to all patients undergoing diagnostic EGD.展开更多
The value of social security funds, has always been an important part of our country social security enterprise as a whole, it is the one of the main ways to realize the social stability and national economic income. ...The value of social security funds, has always been an important part of our country social security enterprise as a whole, it is the one of the main ways to realize the social stability and national economic income. In the triple pressure with ageing population, inflation and social security transition, the value of the social security fund in our country is particularly acute. Analyses the receipts and expenditures of social security funds, investment and operation structure and put forward some rationalization proposal, which has significant meaning for a better play to the role of the social security fund and actively promote the innovation and development of China＇s social security fund management.展开更多
基金Projects(50905144,51275415)supported by the National Natural Science Foundation of ChinaProject supported by the Program for New Century Excellent Talents in University,ChinaProject(B08040)supported by the Program of Introducing Talents of Discipline to Universities,China("111"Project)
文摘In order to develop the warming bending technology of the large diameter thin-walled（LDTW） commercial pure titanium alloy CP-Ti tubes, the warm bending mechanism of the extrados and intrados of LDTW CP-Ti tubes was researched. By EBSD analysis and Vickers hardness test, the changes of microstructure and strength of the tubes at different bending temperatures of 293, 423 and 573 K, were analyzed. The results show： 1） The extrados of the bent tube deforms mainly by slip, along with few twinning, and the preferred orientation is similar to that of the initial tube; the intrados of the bent tube experiences compression deformation mainly by {1 012} tensile twinning, and the twinning makes the preferred orientation of wall materials change sharply. 2） The Vickers hardness values of both the extrados and intrados of the samples after bending increase greatly; the Vickers hardness values of the intrados are much higher than those of the extrados, and Vickers hardness values of the RD-TD planes are always higher than those of the RD-LD planes, which are related to the different deformation mechanisms.
基金West Virginia State Coal and Energy Research Bureau(WVCERB)the Department of Mining Engineering,West Virginia University
文摘Hydrodynamic cavitaion venturi tube technique is used for pico and nano bubble generations in coal column flotation. In order to determine the optimal design of hydrodynamic cavitation venture tube for pico and nano bubble generation, a four-factor three-level Central Composite Design of Experimental was conducted for investigating four important design parameters of cavitation venturi tube governing the median size and the volume of pico and nano bubbles. The test results showed that maximum volume of pico and nano bubbles, 65–75%, and minimum mean pico and nano bubble size,150–240 nm, were achieved at the medium ratio of the diameter of outlet of the venturi-tube and diameter of throat(3–4), medium outlet angle(11–13°), high inlet angle(26–27°) and high ratio of the length of the throat and the diameter of throat(2.3–3). Study the effects of the producing pico and nano bubbles on fine coal flotation was performed in a 5 cm diameter 260 cm height flotation column. The optimal percentage of pico and nano bubbles was about 70%, which produced maximum combustible material recovery of 86% with clean coal ash content of 11.7%.
基金Hi-tech Research and Development Program of ChinaGrant number:863 program#2006AA03Z441+1 种基金Guangdong Province Scienceand Technology Supporting ProgramGrant number:Project#2006B35830001
文摘A novel biological small-diameter vascular graft was evaluated in a canine model. 3 cm long segments with 4 mm I.D. were implanted end-to-end in the carotid position of 12 dogs for 6 months. Color Doppler sonography was performed at the first week post-operation, and angiography was then administered to 9 grafts at 4th week, 12th week and 24th week respectively to monitor the graft pantency and blood flow characteristics. Vascular samples containing the grafts were collected at 1st week, 8th week, 12th week and 24th week after implantation. Morphological changes of the grafts were observed by optical and scanning electron microscopic (SEM) studies and compared with that of the original prosthesis and the normal host vessel. All grafts were patent throughout the experiment except one graft. Histopathology and SEM demonstrated both a nearly complete inner capsule of varied thickness lining the graft luminal surface and connective tissue adventitia formation at one-week post-operation. The neointima became confluent at 8 weeks and then compact but had no signs of hyperplasia up to 12 weeks; meanwhile on the neointimal surface newly grown endothelial-like cells were migrating from the stoma to the middle portion. The grafts also illustrated endothelialization in many “islands” in the mid-segment luminal surface of the grafts. In addition, the closer distance the cells towards the stoma were, the more morphological similarity the cells with the normal endothelial were. Taken together, the biological vascular graft remained patent for 24 weeks as a carotid prosthesis, characterized by the early and complete neointima formation plus endothelialization starting before 12 weeks post grafting. Therefore, the graft seems suitable for reconstruction of vascular lesions in dogs. Further studies may be carried out to extend the graft application for the clinical use.
文摘AIM： to compare the feasibility and patients＇ tolerance of esophagogastroduodenoscopy （EGD） using a thin endoscope with those of conventional oral EGD and to determine the optimal route of introduction of smallcaliber endoscopes. METHODS： One hundred and sixty outpatients referred for diagnostic EGD were randomly allocated to 3 groups： conventional （C）-EGD （9.8 mm in diameter）, transnasal （TN）-EGD and transoral （TO）-EGD （5.9 mm in diameter）. Pre-EGD anxiety was measured using a 100-mm visual analogue scale （VAS）. After EGD, patients and endoscopists completed a questionnaire on the pain, nausea, choking, overall discomfort, and quality of the examination either using VAS or answering some questions. The duration of EGD was timed. Blood oxygen saturation （SaO2） and heart rate （HR） were monitored during EGD. RESULTS： Twenty-one patients refused to participate in the study. The 3 groups were well-matched for age, gender, experience with EGD, and anxiety. EGD was completed in 91.1% （41/45）, 97.5% （40/41）, and 96.2% （51/53） of cases in TN-EGD, TO-EGD, and C-EGD groups, respectively. TN-EGD lasted longer （3.11 ± 1.60 min） than TO-EGD （2.25 ± 1.45 min） and C-EGD （2.49 ± 1.64 rain） （P 〈 0.05）. The overall tolerance was higher （P 〈 0.05） and the overall discomfort was lower （P 〈 0.05） in TN-EGD group than in C-EGD group. EGD was tolerated ＂better than expected＂ in 73.2% of patients in TN-EGD group and 55% and 39.2% of patients in TO-EGD and C-EGD groups, respectively （P 〈 0.05）. Endoscopy was tolerated ＂worst than expected＂ in 4.9% of patients in TN-EGD group and 17.5% and 23.5% of patients in TO- EGD and C-EGD groups, respectively （P 〈 0.05）. TN-EGD caused mild epistaxis in one case, The ability to insuffiate air, wash the lens, and suction of the thin endoscope were lower than those of conventional instrument （P 〈 0,001）, All biopsies performed were adequate for histological assessment. CONCLUSION： Diagnostic TN-EGD is better tolerated than C-EGD, Narrow-diameter endoscope has a level of diagnostic accuracy comparable to that of conventional gastroscope, even though some technical characteristics of these instruments should be improved, Transnasal EGD with narrow-diameter endoscope should be proposed to all patients undergoing diagnostic EGD.
文摘The value of social security funds, has always been an important part of our country social security enterprise as a whole, it is the one of the main ways to realize the social stability and national economic income. In the triple pressure with ageing population, inflation and social security transition, the value of the social security fund in our country is particularly acute. Analyses the receipts and expenditures of social security funds, investment and operation structure and put forward some rationalization proposal, which has significant meaning for a better play to the role of the social security fund and actively promote the innovation and development of China＇s social security fund management.
