INTRODUCTIONIn China,primary liver cancer (PLC) ranks secondin cancer mortality since the 1990s.In the field ofPLC treatment,surgical resection remains the best,which includes large PLC resection,small PLCresection,re...INTRODUCTIONIn China,primary liver cancer (PLC) ranks secondin cancer mortality since the 1990s.In the field ofPLC treatment,surgical resection remains the best,which includes large PLC resection,small PLCresection,re-resection of subclinical recurrence,aswell as cytoreduction and sequential resection forunresectable PLC.However,recurrence展开更多
Shunt and devascularization have totally different effects on hemodynamics of the portal venous system , and the actual results of combined shunt and devascularization should be determined by more clinical observation...Shunt and devascularization have totally different effects on hemodynamics of the portal venous system , and the actual results of combined shunt and devascularization should be determined by more clinical observations. This study aimed to evaluate effects on hemodynamics of the portal venous system after conventional spleno-renal shunt combined with pericardial devascularization and pericardial devascularization only. METHODS: In 20 patients who had received conventional splenorenal shunt combined with pericardial devascularization(CP) and 18 who had received pericardial devascularization and splenectomy (PCDV), hemodynamic parameters of the portal venous system were studied by magnetic resonance angiography 1 week before and 2 weeks after operation. Free portal pressure was detected continuously by a transducer during the operation. RESULTS: Compared to the preoperative data, a decreased flow of the portal vein (PVF) (563.12±206.42 ml/min vs 1080.63±352.85 ml/min, P<0.05), a decreased diameter of the portal vein (PVD) (1.20±0.11 cm vs 1.30±0.16 cm, P<0.01 ), a decreased free portal preasure ( FPP ) (21.50±2.67 mmHg vs 29.88±2.30 mmHg, P<0.01) and an increased flow of the superior mesenteric vein (SMVF) (1105.45±309.03 ml/min vs 569.13±178.46 ml/min, P < 0.05) were found in the CP group after operation; a decreased PVD (1.27±0.16 cm vs 1.40±0.23 cm, P<0.05), a decreased PVF (684.60±165.73 ml/min vs 1175.64±415.09 ml/min, P<0.05), a decreased FPP (24.40±3.78 mmHg vs 28.80±3.56 mmHg, P<0.05) and an increased SMVF (697.91+121.83 ml/min vs 521.30±115.82 ml/min, P<0.05) were found in the PCDV group. After operation, the PVF of CP group (563.12±206.42 ml/min vs 684.60±165.73 ml/min, P>0.05) was not decreased significantly while FPP (21.50±2.67 mmHg vs 24.40±3.78 mmHg, P< 0.01) was decreased significantly as compared with that of the PCDV group. PVF and FPP could be decreased by both surgical procedures, but the effect of decreasing FPP is much better in the combined procedures than in PCDV. Since th展开更多
Endoscopic retrograde cholangiopancrea tography(ERCP) is the most complex gastrointestinal procedure,which needs patients' cooperation. The aim of this study was to observe the quality and safey of sedation with p...Endoscopic retrograde cholangiopancrea tography(ERCP) is the most complex gastrointestinal procedure,which needs patients' cooperation. The aim of this study was to observe the quality and safey of sedation with propofol in patients undergoing therapeutic ERCP. METHODS:Seventy patients who had undergone therapeutic ERCP were randomly divided into two groups.One group, given intravenously propofol, and the other sedated with routine method, served as the control. Blood pressure, heart rate,oxygen saturation were monitored and cardiorespiratory event was observed. Patient cooperation,performance, recovery time and amnesia served as variables postoperation. RESULTS:Blood pressure elevated in four patients in the propofol group, less than in the control group(P<0.01). Seven patients showed decreased blood pressure after administration of propofol,but none in the control group (P<0.01). Twelve patients in the control group showed mild or significant resistance, but none in the propofol group (P<0.01). The time for performance in the propofol group(P<0.05) was shorter than in the control group. Patient recovery was quicker in the propofol group than in the control group (P<0.01). The degree of amnesia better in the propofol group than in the control group ( P<0.01). The degree of amnesia was also better in the propofol group than in the control group (P<0.01). CONCLUSIONS:Propofol proves to be an excellent sedative for therapeutic ERCP. Being effective and safe, it shows a shorter ERCP duration but quick recovery and better amnesia. It is better than other routine sedatives.展开更多
Nonalcoholic fatty liver disease(NAFLD) is a common chronic liver disease in China, of which diabetic fatty liver (DFL) accounts for a large proportion in clinic. DFL is a disease without specific clinical features an...Nonalcoholic fatty liver disease(NAFLD) is a common chronic liver disease in China, of which diabetic fatty liver (DFL) accounts for a large proportion in clinic. DFL is a disease without specific clinical features and lacking of confirmatory laboratory tests, and the etiology of hepatic steatosis remains poorly understood. The aim of this paper was to explore the clinical characteristics and to determine associated risk factors in type 2 diabetes patients with fatty liver. METHODS: A total of 166 patients, 53 in DFL group and 113 in NDFL(diabetes without fatty liver) group participated in this study. Serum fasting blood glucose (FBG), alanine aminotransferase(ALT), aspartate aminotransferase (AST), alkaline phosphate (AKP), gamma glutamyl transpeptidase (GGT), total cholesterol (TC), triglyceride (TG), high density lipoprotein-cholesterol (HDL-C) were measured in both groups. And these variables were analyzed by using Student' s t test and logistic regression model. RESULTS:A progressive increase in the level of FBG, ALT, AST, AKP, GGT, TG( P<0.05) and a decrease of HDL-C(P<0.01)were observed from DFL group to NDFL group. And there was no statistical difference in the level of TC between the two groups. CONCLUSIONS:Dyslipidemia, dysglycemia and elevation of liver enzyme can be seen more frequently in the DFL patients than in the NDFL patients. The successive escalation of serum ALT and TG levels and the lower HDL-C level are the independent risk factors of DFL.展开更多
AIM： To evaluate the effect of intrahepatic transplantation of hepatic oval cells （HOC） on fulminant hepatic failure （FHF） in rats.METHODS： HOC obtained from rats were labeled with green fluocescent protein （GF...AIM： To evaluate the effect of intrahepatic transplantation of hepatic oval cells （HOC） on fulminant hepatic failure （FHF） in rats.METHODS： HOC obtained from rats were labeled with green fluocescent protein （GFP） or 5, 6- carboxyfluorescein diacetate succinmidyl ester （CFDASE）. Cell fluorescence was observed under fluorescent microscope at 6, 24, 48 and 72 h after labeling. CFDA- SE labeled HOC （5 × 10^6 cells each rat） were injected into livers of rats with FHF induced by D-galactosamine. Serum albumin （ALB）, alanine aminotransferase （ALT）, aspartate aminotransferase （AST） and total bilirubin （TBil） levels were measured at different time points. Liver function of rats was examined on days 3, 7, 14 and 21 after HOC transplantation.RESULTS： The positive rate of GFP and CFDA-SE labeled HOC was 10% and 90%, respectively, with no significant change in cell viabilities. The survival rate was higher in HOC transplantation group than in control group, especially 48 （9/15 vs 6/15） and 72 h （9/15 vs 4/15） after HOC transplantation. The serum ALT, AST and TBil levels were decreased while the serum AIb level was increased after HOC transplantation. Fluorescence became faded and diffused in liver tissues, suggesting that proliferation and differentiation occur in transplanted HOC.CONCLUSION： CFDA-SE is superior to GFP in labeling HOC, although fluorescence intensity is decreased progressively with cell division. HOC transplantation can improve the liver function and increase the survival rate of recipients.展开更多
INTRODUCTIONDouble primary esophageal carcinoma is defined ashaving two loci of squamous cell cancersimultaneously or consecutively developing indifferent sites of esophagus.This rare diseaseappears mostly in the lite...INTRODUCTIONDouble primary esophageal carcinoma is defined ashaving two loci of squamous cell cancersimultaneously or consecutively developing indifferent sites of esophagus.This rare diseaseappears mostly in the literature as case reports,reports about its treatment are even moreinfrequent.Here we present our experiences展开更多
AIM To investigate the effects of TRH in DVC on motility of the gallbladder in rabbits. METHODS After fasted for 15h - 18h , rabbits were anesthetized with urethane (1 0g/kg) . Gallbladder pressure (GP) w...AIM To investigate the effects of TRH in DVC on motility of the gallbladder in rabbits. METHODS After fasted for 15h - 18h , rabbits were anesthetized with urethane (1 0g/kg) . Gallbladder pressure (GP) was measured by a frog bladder perfused with normal saline. RESULTS After microinjection of TRH (8 8nmol, 1μl ) into DVC, GP was raised and the frequency of phasic contraction of gallbladder (FPCGB) increased. All the doses of TRH (0 13, 0 25, 0 50, 0 80, 1 30nmol , 1μl ) injected into DVC could excite the motility of gallblader. As the dose of TRH was enlarged, the amplitude and duration of the reaction increased. Effects of TRH in DVC on motility of the gallbladder could be completely abolished by atropine ( 0 2mg/g , i.v.) or vagotomy, but could not be inhibited by phentolamine iv (1 5mg/g) or propranolol iv (1.5mg/g) or by transecting the spinal cord. CONCLUSION Thyrotropin releasing hormone in DVC can excite motility of gallbladder. This effect was mediated by vagus nerves and peripheral M receptor. Its physiological significance may be related to maintaining the phasic contraction of gallbladder in interdigestive period.展开更多
In this paper, an SQP type algorithm with a new nonmonotone line search technique for general constrained optimization problems is presented. The new algorithm does not have to solve the second order correction subpro...In this paper, an SQP type algorithm with a new nonmonotone line search technique for general constrained optimization problems is presented. The new algorithm does not have to solve the second order correction subproblems for each iterations, but still can circumvent the so-called Maratos effect. The algorithm's global convergence and superlinear convergent rate have been proved. In addition, we can prove that, after a few iterations, correction subproblems need not be solved, so computation amount of the algorithm will be decreased much more. Numerical experiments show that the new algorithm is effective.展开更多
In this paper, first, we present the comparison theorem and the (generalized) Stein-Rosenberg theorem for the GMPOR method, which improves some recent results([9,11,13]). Second, we also give the convergent theorem of...In this paper, first, we present the comparison theorem and the (generalized) Stein-Rosenberg theorem for the GMPOR method, which improves some recent results([9,11,13]). Second, we also give the convergent theorem of the GMPOR method, which generalizes the corresponding result of [9]. Finally, we provide the real interval such that the generalized extrapolated Jacobi iterative method and the generalized SOR methods simultaneously converge, one of the main results in [1] is extended.展开更多
AIM To obtain human and murine cDNAsencoding IFN--y inducible protein 10 (lP--10) andcytokine responsive gene--2 (Crg-2).METHODS The encoding genes of lP-10 and Crg2 were amplified by RT--PCR from Cultured humanfibrob...AIM To obtain human and murine cDNAsencoding IFN--y inducible protein 10 (lP--10) andcytokine responsive gene--2 (Crg-2).METHODS The encoding genes of lP-10 and Crg2 were amplified by RT--PCR from Cultured humanfibroblast cells and Balb/ c mouse liver treatedby IFN-y and TNF-a, respectively, and clonedinto plasmids of PUC19 and PGEM3Zf(+ ).RESULTS The nucleotide sequences ot theamplified DNA were confirmed by endonucleasesdigestion and sequencing.CONCLUSION Recombinant lP-10/ crg--2 geneclones with 306 hp and 314 hp inserts wereestablished for further research on biologicalactivities and ligands of hiP-10/mCrg--2.展开更多
On the condition of the width to thickness ratio 625 of rolled strip, the asymmetrical cold strip rolling process about the width center is studied by using computer numerical simulation method and experimental method...On the condition of the width to thickness ratio 625 of rolled strip, the asymmetrical cold strip rolling process about the width center is studied by using computer numerical simulation method and experimental method. The simulated results of the transverse distributions of the rolling pressure, the 2-directional frictions and the front and back tensions agree with the experimental results well. It is an important discovery that the rolling pressure has three peak values across the strip width on the condition of large width to thickness ratio.展开更多
The offshore platform with bucket foundations is a;new type of offshore platform that distinguishes from traditional template platforms by replacing driven piles with bucket foundations. The suction penentration of bu...The offshore platform with bucket foundations is a;new type of offshore platform that distinguishes from traditional template platforms by replacing driven piles with bucket foundations. The suction penentration of bucket foundation is a complicated hydro-dynamic process. The key of this process is the seepage field caused by the difference of pressure applied on purpose inside and outside the bucket. The appearance and developement of seepage field has a decisive influence on the suction penetration process. In this study, the finite element analysis method is applied to the dynamic simulation of the seepage field of suction penetration of bucket foundation. A criterion is suggested to distinguish the hydro-dynamic stability of the soil inside the bucket according to the critical hydraulic gradient method. The reliability of the model and its applicability to engineering practice have been proved through comparison between the results of model test and finite element calculation.展开更多
The composite of Ti matrix with TiB whisker reinforcement has been successfully fabricated. The content of TiB whisker in Ti matrix can reach about 30 vol. pet. Metallographic examination, morphology and microstructur...The composite of Ti matrix with TiB whisker reinforcement has been successfully fabricated. The content of TiB whisker in Ti matrix can reach about 30 vol. pet. Metallographic examination, morphology and microstructure of TiB whisker, interface structure between TiB whisker and Ti matrix were investigated using optical microscope, SEM, TEM and HREM technology. The diameter distribution of TiB whisker is from 0.1 mu m to 3.5 mu m and the aspect ratio of TiB whisker is from 10 to 20. The cross-section of whisker is generally polygon. Because of good compatibility between TiB whisker and Ti matrix it is identified that there is no obvious interaction of Ti matrix with TiB reinforcement and TiB whisker reinforced Ti matrix composites have excellent elevated properties.展开更多
A series of aryloxy-abet ic acids were synthesiedby the react ion of subst nuted plenols with cbloroaceticac id under the condit ion of microwave irradiation and withsol id base as a support. Tits method haB the advan...A series of aryloxy-abet ic acids were synthesiedby the react ion of subst nuted plenols with cbloroaceticac id under the condit ion of microwave irradiation and withsol id base as a support. Tits method haB the advantage ofbetter yields, shorter reaction time, and convenience展开更多
A quasi-steady time domain method is developed for the prediction of dynamic behavior of a mooring system under the environmental disturbances, such as regular or irregular waves, winds and currents. The mooring force...A quasi-steady time domain method is developed for the prediction of dynamic behavior of a mooring system under the environmental disturbances, such as regular or irregular waves, winds and currents. The mooring forces are obtained in a static sense at each instant. The dynamic feature of the mooring cables can be obtained by incorporating the extended 3-D lumped-mass method with the known ship motion history. Some nonlinear effects, such as the influence of the instantaneous change of the wetted hull surface on the hydrostatic restoring forces and Froude-Krylov forces, are included. The computational results show a satisfactory agreement with the experimental ones.展开更多
文摘INTRODUCTIONIn China,primary liver cancer (PLC) ranks secondin cancer mortality since the 1990s.In the field ofPLC treatment,surgical resection remains the best,which includes large PLC resection,small PLCresection,re-resection of subclinical recurrence,aswell as cytoreduction and sequential resection forunresectable PLC.However,recurrence
文摘Shunt and devascularization have totally different effects on hemodynamics of the portal venous system , and the actual results of combined shunt and devascularization should be determined by more clinical observations. This study aimed to evaluate effects on hemodynamics of the portal venous system after conventional spleno-renal shunt combined with pericardial devascularization and pericardial devascularization only. METHODS: In 20 patients who had received conventional splenorenal shunt combined with pericardial devascularization(CP) and 18 who had received pericardial devascularization and splenectomy (PCDV), hemodynamic parameters of the portal venous system were studied by magnetic resonance angiography 1 week before and 2 weeks after operation. Free portal pressure was detected continuously by a transducer during the operation. RESULTS: Compared to the preoperative data, a decreased flow of the portal vein (PVF) (563.12±206.42 ml/min vs 1080.63±352.85 ml/min, P<0.05), a decreased diameter of the portal vein (PVD) (1.20±0.11 cm vs 1.30±0.16 cm, P<0.01 ), a decreased free portal preasure ( FPP ) (21.50±2.67 mmHg vs 29.88±2.30 mmHg, P<0.01) and an increased flow of the superior mesenteric vein (SMVF) (1105.45±309.03 ml/min vs 569.13±178.46 ml/min, P < 0.05) were found in the CP group after operation; a decreased PVD (1.27±0.16 cm vs 1.40±0.23 cm, P<0.05), a decreased PVF (684.60±165.73 ml/min vs 1175.64±415.09 ml/min, P<0.05), a decreased FPP (24.40±3.78 mmHg vs 28.80±3.56 mmHg, P<0.05) and an increased SMVF (697.91+121.83 ml/min vs 521.30±115.82 ml/min, P<0.05) were found in the PCDV group. After operation, the PVF of CP group (563.12±206.42 ml/min vs 684.60±165.73 ml/min, P>0.05) was not decreased significantly while FPP (21.50±2.67 mmHg vs 24.40±3.78 mmHg, P< 0.01) was decreased significantly as compared with that of the PCDV group. PVF and FPP could be decreased by both surgical procedures, but the effect of decreasing FPP is much better in the combined procedures than in PCDV. Since th
文摘Endoscopic retrograde cholangiopancrea tography(ERCP) is the most complex gastrointestinal procedure,which needs patients' cooperation. The aim of this study was to observe the quality and safey of sedation with propofol in patients undergoing therapeutic ERCP. METHODS:Seventy patients who had undergone therapeutic ERCP were randomly divided into two groups.One group, given intravenously propofol, and the other sedated with routine method, served as the control. Blood pressure, heart rate,oxygen saturation were monitored and cardiorespiratory event was observed. Patient cooperation,performance, recovery time and amnesia served as variables postoperation. RESULTS:Blood pressure elevated in four patients in the propofol group, less than in the control group(P<0.01). Seven patients showed decreased blood pressure after administration of propofol,but none in the control group (P<0.01). Twelve patients in the control group showed mild or significant resistance, but none in the propofol group (P<0.01). The time for performance in the propofol group(P<0.05) was shorter than in the control group. Patient recovery was quicker in the propofol group than in the control group (P<0.01). The degree of amnesia better in the propofol group than in the control group ( P<0.01). The degree of amnesia was also better in the propofol group than in the control group (P<0.01). CONCLUSIONS:Propofol proves to be an excellent sedative for therapeutic ERCP. Being effective and safe, it shows a shorter ERCP duration but quick recovery and better amnesia. It is better than other routine sedatives.
文摘Nonalcoholic fatty liver disease(NAFLD) is a common chronic liver disease in China, of which diabetic fatty liver (DFL) accounts for a large proportion in clinic. DFL is a disease without specific clinical features and lacking of confirmatory laboratory tests, and the etiology of hepatic steatosis remains poorly understood. The aim of this paper was to explore the clinical characteristics and to determine associated risk factors in type 2 diabetes patients with fatty liver. METHODS: A total of 166 patients, 53 in DFL group and 113 in NDFL(diabetes without fatty liver) group participated in this study. Serum fasting blood glucose (FBG), alanine aminotransferase(ALT), aspartate aminotransferase (AST), alkaline phosphate (AKP), gamma glutamyl transpeptidase (GGT), total cholesterol (TC), triglyceride (TG), high density lipoprotein-cholesterol (HDL-C) were measured in both groups. And these variables were analyzed by using Student' s t test and logistic regression model. RESULTS:A progressive increase in the level of FBG, ALT, AST, AKP, GGT, TG( P<0.05) and a decrease of HDL-C(P<0.01)were observed from DFL group to NDFL group. And there was no statistical difference in the level of TC between the two groups. CONCLUSIONS:Dyslipidemia, dysglycemia and elevation of liver enzyme can be seen more frequently in the DFL patients than in the NDFL patients. The successive escalation of serum ALT and TG levels and the lower HDL-C level are the independent risk factors of DFL.
基金Supported by Tianjin Science Committee,Grant No.05SYSYJC02600Tianjin Health Bureau,Grant No.05KYR01
文摘AIM： To evaluate the effect of intrahepatic transplantation of hepatic oval cells （HOC） on fulminant hepatic failure （FHF） in rats.METHODS： HOC obtained from rats were labeled with green fluocescent protein （GFP） or 5, 6- carboxyfluorescein diacetate succinmidyl ester （CFDASE）. Cell fluorescence was observed under fluorescent microscope at 6, 24, 48 and 72 h after labeling. CFDA- SE labeled HOC （5 × 10^6 cells each rat） were injected into livers of rats with FHF induced by D-galactosamine. Serum albumin （ALB）, alanine aminotransferase （ALT）, aspartate aminotransferase （AST） and total bilirubin （TBil） levels were measured at different time points. Liver function of rats was examined on days 3, 7, 14 and 21 after HOC transplantation.RESULTS： The positive rate of GFP and CFDA-SE labeled HOC was 10% and 90%, respectively, with no significant change in cell viabilities. The survival rate was higher in HOC transplantation group than in control group, especially 48 （9/15 vs 6/15） and 72 h （9/15 vs 4/15） after HOC transplantation. The serum ALT, AST and TBil levels were decreased while the serum AIb level was increased after HOC transplantation. Fluorescence became faded and diffused in liver tissues, suggesting that proliferation and differentiation occur in transplanted HOC.CONCLUSION： CFDA-SE is superior to GFP in labeling HOC, although fluorescence intensity is decreased progressively with cell division. HOC transplantation can improve the liver function and increase the survival rate of recipients.
文摘INTRODUCTIONDouble primary esophageal carcinoma is defined ashaving two loci of squamous cell cancersimultaneously or consecutively developing indifferent sites of esophagus.This rare diseaseappears mostly in the literature as case reports,reports about its treatment are even moreinfrequent.Here we present our experiences
文摘AIM To investigate the effects of TRH in DVC on motility of the gallbladder in rabbits. METHODS After fasted for 15h - 18h , rabbits were anesthetized with urethane (1 0g/kg) . Gallbladder pressure (GP) was measured by a frog bladder perfused with normal saline. RESULTS After microinjection of TRH (8 8nmol, 1μl ) into DVC, GP was raised and the frequency of phasic contraction of gallbladder (FPCGB) increased. All the doses of TRH (0 13, 0 25, 0 50, 0 80, 1 30nmol , 1μl ) injected into DVC could excite the motility of gallblader. As the dose of TRH was enlarged, the amplitude and duration of the reaction increased. Effects of TRH in DVC on motility of the gallbladder could be completely abolished by atropine ( 0 2mg/g , i.v.) or vagotomy, but could not be inhibited by phentolamine iv (1 5mg/g) or propranolol iv (1.5mg/g) or by transecting the spinal cord. CONCLUSION Thyrotropin releasing hormone in DVC can excite motility of gallbladder. This effect was mediated by vagus nerves and peripheral M receptor. Its physiological significance may be related to maintaining the phasic contraction of gallbladder in interdigestive period.
文摘In this paper, an SQP type algorithm with a new nonmonotone line search technique for general constrained optimization problems is presented. The new algorithm does not have to solve the second order correction subproblems for each iterations, but still can circumvent the so-called Maratos effect. The algorithm's global convergence and superlinear convergent rate have been proved. In addition, we can prove that, after a few iterations, correction subproblems need not be solved, so computation amount of the algorithm will be decreased much more. Numerical experiments show that the new algorithm is effective.
文摘In this paper, first, we present the comparison theorem and the (generalized) Stein-Rosenberg theorem for the GMPOR method, which improves some recent results([9,11,13]). Second, we also give the convergent theorem of the GMPOR method, which generalizes the corresponding result of [9]. Finally, we provide the real interval such that the generalized extrapolated Jacobi iterative method and the generalized SOR methods simultaneously converge, one of the main results in [1] is extended.
基金Supported by the 0utstanding Youth Fund from National Natural Science Foundation of China,No.39625023
文摘AIM To obtain human and murine cDNAsencoding IFN--y inducible protein 10 (lP--10) andcytokine responsive gene--2 (Crg-2).METHODS The encoding genes of lP-10 and Crg2 were amplified by RT--PCR from Cultured humanfibroblast cells and Balb/ c mouse liver treatedby IFN-y and TNF-a, respectively, and clonedinto plasmids of PUC19 and PGEM3Zf(+ ).RESULTS The nucleotide sequences ot theamplified DNA were confirmed by endonucleasesdigestion and sequencing.CONCLUSION Recombinant lP-10/ crg--2 geneclones with 306 hp and 314 hp inserts wereestablished for further research on biologicalactivities and ligands of hiP-10/mCrg--2.
文摘On the condition of the width to thickness ratio 625 of rolled strip, the asymmetrical cold strip rolling process about the width center is studied by using computer numerical simulation method and experimental method. The simulated results of the transverse distributions of the rolling pressure, the 2-directional frictions and the front and back tensions agree with the experimental results well. It is an important discovery that the rolling pressure has three peak values across the strip width on the condition of large width to thickness ratio.
文摘The offshore platform with bucket foundations is a;new type of offshore platform that distinguishes from traditional template platforms by replacing driven piles with bucket foundations. The suction penentration of bucket foundation is a complicated hydro-dynamic process. The key of this process is the seepage field caused by the difference of pressure applied on purpose inside and outside the bucket. The appearance and developement of seepage field has a decisive influence on the suction penetration process. In this study, the finite element analysis method is applied to the dynamic simulation of the seepage field of suction penetration of bucket foundation. A criterion is suggested to distinguish the hydro-dynamic stability of the soil inside the bucket according to the critical hydraulic gradient method. The reliability of the model and its applicability to engineering practice have been proved through comparison between the results of model test and finite element calculation.
文摘The composite of Ti matrix with TiB whisker reinforcement has been successfully fabricated. The content of TiB whisker in Ti matrix can reach about 30 vol. pet. Metallographic examination, morphology and microstructure of TiB whisker, interface structure between TiB whisker and Ti matrix were investigated using optical microscope, SEM, TEM and HREM technology. The diameter distribution of TiB whisker is from 0.1 mu m to 3.5 mu m and the aspect ratio of TiB whisker is from 10 to 20. The cross-section of whisker is generally polygon. Because of good compatibility between TiB whisker and Ti matrix it is identified that there is no obvious interaction of Ti matrix with TiB reinforcement and TiB whisker reinforced Ti matrix composites have excellent elevated properties.
文摘A series of aryloxy-abet ic acids were synthesiedby the react ion of subst nuted plenols with cbloroaceticac id under the condit ion of microwave irradiation and withsol id base as a support. Tits method haB the advantage ofbetter yields, shorter reaction time, and convenience
基金The project was financially supported by the Foundation of Doctorate Program of the State Education Commission of China
文摘A quasi-steady time domain method is developed for the prediction of dynamic behavior of a mooring system under the environmental disturbances, such as regular or irregular waves, winds and currents. The mooring forces are obtained in a static sense at each instant. The dynamic feature of the mooring cables can be obtained by incorporating the extended 3-D lumped-mass method with the known ship motion history. Some nonlinear effects, such as the influence of the instantaneous change of the wetted hull surface on the hydrostatic restoring forces and Froude-Krylov forces, are included. The computational results show a satisfactory agreement with the experimental ones.
