AIM:Primary biliary cirrhosis (PBC) is a chronic, cholestatic disease of autoimmune etiology,the histology of which shows a destruction of the intrahepatic bile duct and portal inflammation. Ursodeoxycholic acid (UDCA...AIM:Primary biliary cirrhosis (PBC) is a chronic, cholestatic disease of autoimmune etiology,the histology of which shows a destruction of the intrahepatic bile duct and portal inflammation. Ursodeoxycholic acid (UDCA) is now used as a first-line drug for asymptomatic PBC (aPBC) because it is reported that UDCA decreases mortality and prolongs the time of liver transplantation.However, only 20-30% of patients respond fully to UDCA.Recently,lipoprotein-lowering agents have been found to be effective for PBC.The aim of this study was to examine the safety and efficacy of fenofibrate, a member of the fibrate class of hypolipidemic and anti-inflammatory agent via peroxysome proliferatory-activated receptor α,in patients with aPBC.METHODS:Fenofibrate was administered for twelve weeks in nine patients with aPBC who failed to respond to UDCA.UDCA was used along with fenofibrate during the study.The data from aPBC patients were analyzed to assess the biochemical effect of fenofibrate during the study.RESULTS: The serum levels of alkaline phosphatase (ALP)(285±114.8IU/L) and immunoglobulin M (IgM) (255.8±85.9mg/dl) significantly decreased to 186.9±76.2IU/L and 192.9±67.5mg/dL respectively, after fenofibrate treatment in patients with aPBC (P<0.05). Moreover,the titer of antimitochondrial antibody (AMA) also decreased in 4 of 9 patients with aPBC. No adverse reactions were observed in any patients.CONCLUSION:Fenofibrate appears to be significantly effective in treating patients with aPBC who respond incompletely to UDCA alone.Although the mechanism of fenofibrate on aPBC has not yet been fully clarified,combination therapy using fenofibrate and UDCA might be related to the anti-immunological effects, such as the suppression of AMA production as well as its antiinflammatory effect.展开更多
Almost all the coal is produced from open cut mines in Indonesia. As a consequence of open cut mine application, a great deal of coal is left out in the highwalls of the mined-out pits. Highwall mining systems can be ...Almost all the coal is produced from open cut mines in Indonesia. As a consequence of open cut mine application, a great deal of coal is left out in the highwalls of the mined-out pits. Highwall mining systems can be used to recover this coal. The use of highwall mining systems has increasingly come into play in the US and Australia. However, it is not common in Indonesia. Moreover, Indonesia coal measure is categorized as weak geological condition. Some problems are likely to arise during the application of the highwall mining system for example instability of openings and highwalls due to the roof and pillar failures. Therefore, study of highwall mining system application in Indonesia is needed in order to increase the recovery rate of coal mining in Indonesia. This paper described the characteristics of the highwa!l mining system and discussed the appropriate highwall mining system application in weak geological condition, Indonesia. From the results of a series of laboratory tests and numerical analyses, it can be concluded that the stability of pillars and mine openings in auger mining systems is much higher than that in CHM and an auger mining system is suitable for such as very weak/poor strata conditions. Moreover, the application of backfilling system is very effective for improvement of the stability of pillar and openings.展开更多
Based on the assumption of the plain-strain problem, various optimization or random search methods have been developed for locating the critical slip surfaces in slope-stability analysis, but none of such methods is a...Based on the assumption of the plain-strain problem, various optimization or random search methods have been developed for locating the critical slip surfaces in slope-stability analysis, but none of such methods is applicable to the 3D case. In this paper, a simple Monte Carlo random simulation method is proposed to identify the 3D critical slip surface. Assuming the initial slip to be the lower part of a slip ellipsoid, the 3D critical slip surface is located by means of a minimized 3D safety factor. A column-based 3D slope stability analysis model is used to calculate this factor. In this study, some practical cases of known minimum safety factors and critical slip surfaces in 2D analysis are extended to 3D slope problems to locate the critical slip surfaces. Compared with the 2D result, the resulting 3D critical slip surface has no apparent difference in terms of only cross section, but the associated 3D safety factor is definitely higher.展开更多
Application of the multiobjective evolutionary algorithms to the aerodynamicoptimization design of a centrifugal impeller is presented. The aerodynamic performance of acentrifugal impeller is evaluated by using the th...Application of the multiobjective evolutionary algorithms to the aerodynamicoptimization design of a centrifugal impeller is presented. The aerodynamic performance of acentrifugal impeller is evaluated by using the three-dimensional Navier-Stokes solutions. Thetypical centrifugal impeller is redesigned for maximization of the pressure rise and blade load andminimization of the rotational total pressure loss at the given flow conditions. The Bezier curvesare used to parameterize the three-dimensional impeller blade shape. The present method obtains manyreasonable Pareto optimal designs that outperform the original centrifugal impeller. Detailedobservation of the certain Pareto optimal design demonstrates the feasibility of the presentmultiobjective optimization method tool for turbomachinery design.展开更多
Reduction of Cr(VI) to Cr(III) were studied in a fresh wheat rhizosphere soil (Kuroboku, high humic andosol) pretreated with a basal fertilizer consisting of (NH4)2SO4, P2O5 and KH2PO4 and with K2Cr2O7 by using a rhiz...Reduction of Cr(VI) to Cr(III) were studied in a fresh wheat rhizosphere soil (Kuroboku, high humic andosol) pretreated with a basal fertilizer consisting of (NH4)2SO4, P2O5 and KH2PO4 and with K2Cr2O7 by using a rhizobox system. It was found that rhizosphere exerted a positive effect on Cr(VI) reduction. Part of the reason was the decrease of pH in the rhizosphere due to application of (NH4)2SO4, implying that application of physiologically acid fertilizers would reduce Cr(VI) toxicity to plants.展开更多
Grh2, a green rice leafhopper resistant gene from an indica cultivar DV85, was located on chromosome 11, and two RFLP markers C189 and G1465 were found to be linked to this gene. In order to transfer Grh2 into Taichun...Grh2, a green rice leafhopper resistant gene from an indica cultivar DV85, was located on chromosome 11, and two RFLP markers C189 and G1465 were found to be linked to this gene. In order to transfer Grh2 into Taichung65, a japonica cultivar with elite characters, backcross method with Taichung65 as the recurrent parent was used and the two RFLP markers were converted into CAPS markers for marker assisted selection (MAS). In the BC6F3 population, both phenotypic evaluation and MAS were conducted to screen the resistant plants with Taichung65 background. The linkage distance between CAPS markers and Grh2 was calculated and the efficiency of MAS was analyzed.展开更多
By combining conventional grey correlation analysis, grey clustering method and grey forecasting methods with our multi-goal forecast thoughts and the techniques of grey time series processing, we develop six differen...By combining conventional grey correlation analysis, grey clustering method and grey forecasting methods with our multi-goal forecast thoughts and the techniques of grey time series processing, we develop six different grey earthquake forecast models in this paper. Using the record of major earthquakes in Japan from 1872 to 1995, we forecast future earthquakes in Japan. We develop an earthquake forecast model. By using the major earthquakes in Japan from 1872 to 1984, we forecast earthquakes from 1985 to 1995 and check the precision of the grey earthquake models. We find that the grey system theory can be applied to earthquake forecast. We introduce the above analysis methods and give a real example to evaluate and forecast. We also further discuss the problems of how to improve the precision of earthquake forecast and how to strengthen the forecast models in future research.展开更多
AIM: To investigate the effects of rhubarb on severe acute pancreatitis (SAP) in rats. METHODS: Severe acute pancreatitis was induced by two intraperitoneal injections of cerulein (40 μg/kg body weight) plus 5-h rest...AIM: To investigate the effects of rhubarb on severe acute pancreatitis (SAP) in rats. METHODS: Severe acute pancreatitis was induced by two intraperitoneal injections of cerulein (40 μg/kg body weight) plus 5-h restraint water-immersion stress. Rhubarb (75-150 mg/kg) was orally fed before the first cerulein injection. The degree of pancreatic edema, serum amylase level, local pancreatic blood flow (PBF), and histological alterations were investigated. The effects of rhubarb on pancreatic exocrine secretion in this model were evaluated by comparing with those of somatostatin. RESULTS: In the Cerulein+Stress group, severe edema and diffuse hemorrhage in the pancreas were observed, the pancreatic wet weight (11.60±0.61 g/Kg) and serum amylase (458 490±43 100 U/L) were markedly increased (P<0.01 vs control). In the rhubarb (150 mg/kg) treated rats, necrosis and polymorphonuclear neutrophil (PMN) infiltration in the pancreas were significantly reduced (P<0.01), and a marked decrease (50%) in serum amylase levels was also observed (P<0.01). PBF dropped to 38% (93±5 mL/min per 100 g) of the control in the Cerulein+Stress group and partly recovered in the Cerulein+Stress+Rhubarb 150 mg group (135±12 mL/min per 100 g) (P<0.01). The pancreatic exocrine function was impaired in the SAP rats. The amylase levels of pancreatic juice were reduced in the rats treated with rhubarb or somatostatin, comparing with that of untreated SAP group. The bicarbonate concentration of pancreatic juice was markedly elevated only in the rhubarbtreated group (P<0.01). CONCLUSION: Rhubarb can exert protective effects on SAP, probably by inhibiting the inflammation of pancreas, improving pancreatic microcirculation, and altering exocrine secretion.展开更多
In this study, it was examined whether the dynamics of polymer chains at a surface is different from that in thebulk, and if so, to what extent they differ in terms of surface glass transition temperature and diffusio...In this study, it was examined whether the dynamics of polymer chains at a surface is different from that in thebulk, and if so, to what extent they differ in terms of surface glass transition temperature and diffusion coefficient. Obtainedresults clearly indicate that surface chains can travel for a relatively large distance in comparison with the characteristiclength scale of usual segmental motion even at a temperature below its bulk glass transition temperature, T_g^b. This isconsistent with our previous results that the surface glass transition temperature is much lower than the corresponding T_g^b.Also, it was experimentally revealed that there was a gradient of molecular motion in the surface region.展开更多
Quantitative trait loci (QTL) controlling seed dormancy in rice were identified usingrecombinant inbred lines (RILs) population derived from the cross between a japonicavariety Kinmaze and an indica variety DV85. Seed...Quantitative trait loci (QTL) controlling seed dormancy in rice were identified usingrecombinant inbred lines (RILs) population derived from the cross between a japonicavariety Kinmaze and an indica variety DV85. Seeds of two parental cultivars and each RILwere harvested in 35d after heading. The germination percentage of these seeds at 30℃for 7 days were measured as the degree of seed dormancy. QTL analysis was performed withWindows QTL Cartographer 1.13a program by composite interval mapping. A total of four QTLfor seed dormancy were detected on chromosome 2 (two regions), 5 and 11, respectively.Phenotypic variation explained by each QTL ranged from 8.37 to 17.40%. Responses of suchloci to a dormancy-breaking treatment with dry heat were further detected. The resultsshowed that two alleles of qDOR-2-1 and qDOR-5 from DV85 as well as the allele of qDOR-11 from Kinmaze increased the seed dormancy, which seemed to be easily broken by dry heattreatment. Such loci of seed dormancy may be applied to rice genetic improvement. Theallele of qDOR-2-2 from DV85 increased the seed dormancy, which could not be broken bydry heat treatment.展开更多
Impermeable bentonite or its mixtures have been proposed as candidate materials to be used in the geotechnical disposal of radioactive nuclear waste. These materials are filled in the space between a canister containi...Impermeable bentonite or its mixtures have been proposed as candidate materials to be used in the geotechnical disposal of radioactive nuclear waste. These materials are filled in the space between a canister containing radioactive nuclear waste and an underground chamber to absorb the radionuclide emitting from the canister and simultaneously retard its migration accompanying the perrneation of underground water to prevent the surrounding environment from po1lution. On the basis of the established elastoplastic strain-hardening mechanical model considering the material’s dilatancy character,the authors carry out the stress-strain analysis of a thick-wa1l cylinder in a plane strain state subJected to a pressure difference between internal and external pressures. The analysis may be expected to be a theoretical basis for developing a coupled shear and permeability test apparatus for conducting a permeability test along a sheared plane in a specimen. The apparatus will be used to study the effects of shear strain on the variation of geotechnical materials’ permeability coefficient in order to evaluate the influence of shear strain caused by nonuniform deformation and/or earthquake on the long-term safety of the disposal system of radioactive nuclear waste. The theoretlcal analysls methods in this paper can be directly spread to the analysis of the deformation and stability of tunnels or roadways driven in soft soils or high moisture-bearing soft rocks.展开更多
Since tungsten was chose as the divertor tiles of 1TER, the investigation of tungsten and its coating as plasma facing material (PFM) have been paid more attentions by fusion scientists all over the world. Recent year...Since tungsten was chose as the divertor tiles of 1TER, the investigation of tungsten and its coating as plasma facing material (PFM) have been paid more attentions by fusion scientists all over the world. Recent years, tungsten coatings have been展开更多
The control of core plasma and impurity level of edge plasma has been greatly improved with the development of controlled fusion technology. Refractory metal tungsten or its alloy was paid more attentions owing to its...The control of core plasma and impurity level of edge plasma has been greatly improved with the development of controlled fusion technology. Refractory metal tungsten or its alloy was paid more attentions owing to its high melting temperature, good展开更多
High Z and low Z materials are both the candidate plasma facing materials (PFM), up to now, the typical representative of high Z materials is tungsten, and the representatives of low Z materials are carbon materials (...High Z and low Z materials are both the candidate plasma facing materials (PFM), up to now, the typical representative of high Z materials is tungsten, and the representatives of low Z materials are carbon materials (such as graphite, C/C composite) and beryllium. Most of these materials have been used as PFM limiters and diverter armor tiles of tokamak machines, tungsten, molybdenum and C/C composite are always used as high heat flux components.展开更多
Tungsten is envisaged as one of the main candidate materials for divertor plate of ITER and future fusion reactors. Due to D-T reaction, PFMs would suffer helium irradiation from plasma additional to the high heat loa...Tungsten is envisaged as one of the main candidate materials for divertor plate of ITER and future fusion reactors. Due to D-T reaction, PFMs would suffer helium irradiation from plasma additional to the high heat loads. Helium retention and thermal desorption behavior are largely concerned.展开更多
A new dynamic model for non-Fickian diffu-sion of calcium spark in cardiac myocytes was developed by introducing time lags on the basis of the microscale mass transport theory. Numerical simulation showed that the siz...A new dynamic model for non-Fickian diffu-sion of calcium spark in cardiac myocytes was developed by introducing time lags on the basis of the microscale mass transport theory. Numerical simulation showed that the size of the calcium spark produced by the new dynamic model was larger than that of Fick diffusion and was in more agreement with experimental results. In addition, the time lags of the calcium spark in cardiac myocytes were about 0.1—0.8 ms. These results can be used to understand the mechanism of calcium spark diffusion in cardiac myocytes.展开更多
文摘AIM:Primary biliary cirrhosis (PBC) is a chronic, cholestatic disease of autoimmune etiology,the histology of which shows a destruction of the intrahepatic bile duct and portal inflammation. Ursodeoxycholic acid (UDCA) is now used as a first-line drug for asymptomatic PBC (aPBC) because it is reported that UDCA decreases mortality and prolongs the time of liver transplantation.However, only 20-30% of patients respond fully to UDCA.Recently,lipoprotein-lowering agents have been found to be effective for PBC.The aim of this study was to examine the safety and efficacy of fenofibrate, a member of the fibrate class of hypolipidemic and anti-inflammatory agent via peroxysome proliferatory-activated receptor α,in patients with aPBC.METHODS:Fenofibrate was administered for twelve weeks in nine patients with aPBC who failed to respond to UDCA.UDCA was used along with fenofibrate during the study.The data from aPBC patients were analyzed to assess the biochemical effect of fenofibrate during the study.RESULTS: The serum levels of alkaline phosphatase (ALP)(285±114.8IU/L) and immunoglobulin M (IgM) (255.8±85.9mg/dl) significantly decreased to 186.9±76.2IU/L and 192.9±67.5mg/dL respectively, after fenofibrate treatment in patients with aPBC (P<0.05). Moreover,the titer of antimitochondrial antibody (AMA) also decreased in 4 of 9 patients with aPBC. No adverse reactions were observed in any patients.CONCLUSION:Fenofibrate appears to be significantly effective in treating patients with aPBC who respond incompletely to UDCA alone.Although the mechanism of fenofibrate on aPBC has not yet been fully clarified,combination therapy using fenofibrate and UDCA might be related to the anti-immunological effects, such as the suppression of AMA production as well as its antiinflammatory effect.
文摘Almost all the coal is produced from open cut mines in Indonesia. As a consequence of open cut mine application, a great deal of coal is left out in the highwalls of the mined-out pits. Highwall mining systems can be used to recover this coal. The use of highwall mining systems has increasingly come into play in the US and Australia. However, it is not common in Indonesia. Moreover, Indonesia coal measure is categorized as weak geological condition. Some problems are likely to arise during the application of the highwall mining system for example instability of openings and highwalls due to the roof and pillar failures. Therefore, study of highwall mining system application in Indonesia is needed in order to increase the recovery rate of coal mining in Indonesia. This paper described the characteristics of the highwa!l mining system and discussed the appropriate highwall mining system application in weak geological condition, Indonesia. From the results of a series of laboratory tests and numerical analyses, it can be concluded that the stability of pillars and mine openings in auger mining systems is much higher than that in CHM and an auger mining system is suitable for such as very weak/poor strata conditions. Moreover, the application of backfilling system is very effective for improvement of the stability of pillar and openings.
文摘Based on the assumption of the plain-strain problem, various optimization or random search methods have been developed for locating the critical slip surfaces in slope-stability analysis, but none of such methods is applicable to the 3D case. In this paper, a simple Monte Carlo random simulation method is proposed to identify the 3D critical slip surface. Assuming the initial slip to be the lower part of a slip ellipsoid, the 3D critical slip surface is located by means of a minimized 3D safety factor. A column-based 3D slope stability analysis model is used to calculate this factor. In this study, some practical cases of known minimum safety factors and critical slip surfaces in 2D analysis are extended to 3D slope problems to locate the critical slip surfaces. Compared with the 2D result, the resulting 3D critical slip surface has no apparent difference in terms of only cross section, but the associated 3D safety factor is definitely higher.
文摘Application of the multiobjective evolutionary algorithms to the aerodynamicoptimization design of a centrifugal impeller is presented. The aerodynamic performance of acentrifugal impeller is evaluated by using the three-dimensional Navier-Stokes solutions. Thetypical centrifugal impeller is redesigned for maximization of the pressure rise and blade load andminimization of the rotational total pressure loss at the given flow conditions. The Bezier curvesare used to parameterize the three-dimensional impeller blade shape. The present method obtains manyreasonable Pareto optimal designs that outperform the original centrifugal impeller. Detailedobservation of the certain Pareto optimal design demonstrates the feasibility of the presentmultiobjective optimization method tool for turbomachinery design.
基金Project supported by the Interdisciplinary Research Institute of Environmental Sciences, Japan.
文摘Reduction of Cr(VI) to Cr(III) were studied in a fresh wheat rhizosphere soil (Kuroboku, high humic andosol) pretreated with a basal fertilizer consisting of (NH4)2SO4, P2O5 and KH2PO4 and with K2Cr2O7 by using a rhizobox system. It was found that rhizosphere exerted a positive effect on Cr(VI) reduction. Part of the reason was the decrease of pH in the rhizosphere due to application of (NH4)2SO4, implying that application of physiologically acid fertilizers would reduce Cr(VI) toxicity to plants.
基金This work was conducted in Kyushu University,Japan by the first author during his visiting research supported by China Scholarship Counsel(CSC),the“948”Project of the Ministry of Agriculture of Chinathe Program for Outstanding Teachers by the Ministry of Education of China.
文摘Grh2, a green rice leafhopper resistant gene from an indica cultivar DV85, was located on chromosome 11, and two RFLP markers C189 and G1465 were found to be linked to this gene. In order to transfer Grh2 into Taichung65, a japonica cultivar with elite characters, backcross method with Taichung65 as the recurrent parent was used and the two RFLP markers were converted into CAPS markers for marker assisted selection (MAS). In the BC6F3 population, both phenotypic evaluation and MAS were conducted to screen the resistant plants with Taichung65 background. The linkage distance between CAPS markers and Grh2 was calculated and the efficiency of MAS was analyzed.
文摘By combining conventional grey correlation analysis, grey clustering method and grey forecasting methods with our multi-goal forecast thoughts and the techniques of grey time series processing, we develop six different grey earthquake forecast models in this paper. Using the record of major earthquakes in Japan from 1872 to 1995, we forecast future earthquakes in Japan. We develop an earthquake forecast model. By using the major earthquakes in Japan from 1872 to 1984, we forecast earthquakes from 1985 to 1995 and check the precision of the grey earthquake models. We find that the grey system theory can be applied to earthquake forecast. We introduce the above analysis methods and give a real example to evaluate and forecast. We also further discuss the problems of how to improve the precision of earthquake forecast and how to strengthen the forecast models in future research.
文摘AIM: To investigate the effects of rhubarb on severe acute pancreatitis (SAP) in rats. METHODS: Severe acute pancreatitis was induced by two intraperitoneal injections of cerulein (40 μg/kg body weight) plus 5-h restraint water-immersion stress. Rhubarb (75-150 mg/kg) was orally fed before the first cerulein injection. The degree of pancreatic edema, serum amylase level, local pancreatic blood flow (PBF), and histological alterations were investigated. The effects of rhubarb on pancreatic exocrine secretion in this model were evaluated by comparing with those of somatostatin. RESULTS: In the Cerulein+Stress group, severe edema and diffuse hemorrhage in the pancreas were observed, the pancreatic wet weight (11.60±0.61 g/Kg) and serum amylase (458 490±43 100 U/L) were markedly increased (P<0.01 vs control). In the rhubarb (150 mg/kg) treated rats, necrosis and polymorphonuclear neutrophil (PMN) infiltration in the pancreas were significantly reduced (P<0.01), and a marked decrease (50%) in serum amylase levels was also observed (P<0.01). PBF dropped to 38% (93±5 mL/min per 100 g) of the control in the Cerulein+Stress group and partly recovered in the Cerulein+Stress+Rhubarb 150 mg group (135±12 mL/min per 100 g) (P<0.01). The pancreatic exocrine function was impaired in the SAP rats. The amylase levels of pancreatic juice were reduced in the rats treated with rhubarb or somatostatin, comparing with that of untreated SAP group. The bicarbonate concentration of pancreatic juice was markedly elevated only in the rhubarbtreated group (P<0.01). CONCLUSION: Rhubarb can exert protective effects on SAP, probably by inhibiting the inflammation of pancreas, improving pancreatic microcirculation, and altering exocrine secretion.
基金This work was in part supported by a Gran-in-Aid for Scientific Research (A)(#13355034) from the Ministry of Education, Science, Sports, and Culture, Japan.
文摘In this study, it was examined whether the dynamics of polymer chains at a surface is different from that in thebulk, and if so, to what extent they differ in terms of surface glass transition temperature and diffusion coefficient. Obtainedresults clearly indicate that surface chains can travel for a relatively large distance in comparison with the characteristiclength scale of usual segmental motion even at a temperature below its bulk glass transition temperature, T_g^b. This isconsistent with our previous results that the surface glass transition temperature is much lower than the corresponding T_g^b.Also, it was experimentally revealed that there was a gradient of molecular motion in the surface region.
基金supported by the National Nature Science Foundation of Jiangsu Province,China(BK2003415)Jiangsu Province Tackle Key Problem Foundation(BE2001305).
文摘Quantitative trait loci (QTL) controlling seed dormancy in rice were identified usingrecombinant inbred lines (RILs) population derived from the cross between a japonicavariety Kinmaze and an indica variety DV85. Seeds of two parental cultivars and each RILwere harvested in 35d after heading. The germination percentage of these seeds at 30℃for 7 days were measured as the degree of seed dormancy. QTL analysis was performed withWindows QTL Cartographer 1.13a program by composite interval mapping. A total of four QTLfor seed dormancy were detected on chromosome 2 (two regions), 5 and 11, respectively.Phenotypic variation explained by each QTL ranged from 8.37 to 17.40%. Responses of suchloci to a dormancy-breaking treatment with dry heat were further detected. The resultsshowed that two alleles of qDOR-2-1 and qDOR-5 from DV85 as well as the allele of qDOR-11 from Kinmaze increased the seed dormancy, which seemed to be easily broken by dry heattreatment. Such loci of seed dormancy may be applied to rice genetic improvement. Theallele of qDOR-2-2 from DV85 increased the seed dormancy, which could not be broken bydry heat treatment.
文摘Impermeable bentonite or its mixtures have been proposed as candidate materials to be used in the geotechnical disposal of radioactive nuclear waste. These materials are filled in the space between a canister containing radioactive nuclear waste and an underground chamber to absorb the radionuclide emitting from the canister and simultaneously retard its migration accompanying the perrneation of underground water to prevent the surrounding environment from po1lution. On the basis of the established elastoplastic strain-hardening mechanical model considering the material’s dilatancy character,the authors carry out the stress-strain analysis of a thick-wa1l cylinder in a plane strain state subJected to a pressure difference between internal and external pressures. The analysis may be expected to be a theoretical basis for developing a coupled shear and permeability test apparatus for conducting a permeability test along a sheared plane in a specimen. The apparatus will be used to study the effects of shear strain on the variation of geotechnical materials’ permeability coefficient in order to evaluate the influence of shear strain caused by nonuniform deformation and/or earthquake on the long-term safety of the disposal system of radioactive nuclear waste. The theoretlcal analysls methods in this paper can be directly spread to the analysis of the deformation and stability of tunnels or roadways driven in soft soils or high moisture-bearing soft rocks.
文摘Since tungsten was chose as the divertor tiles of 1TER, the investigation of tungsten and its coating as plasma facing material (PFM) have been paid more attentions by fusion scientists all over the world. Recent years, tungsten coatings have been
文摘The control of core plasma and impurity level of edge plasma has been greatly improved with the development of controlled fusion technology. Refractory metal tungsten or its alloy was paid more attentions owing to its high melting temperature, good
文摘High Z and low Z materials are both the candidate plasma facing materials (PFM), up to now, the typical representative of high Z materials is tungsten, and the representatives of low Z materials are carbon materials (such as graphite, C/C composite) and beryllium. Most of these materials have been used as PFM limiters and diverter armor tiles of tokamak machines, tungsten, molybdenum and C/C composite are always used as high heat flux components.
文摘Tungsten is envisaged as one of the main candidate materials for divertor plate of ITER and future fusion reactors. Due to D-T reaction, PFMs would suffer helium irradiation from plasma additional to the high heat loads. Helium retention and thermal desorption behavior are largely concerned.
基金supported by the National Natural Science Foundation of China(Grant No.10372007)Bio-x center of Peking University and Japan Society for the Promotion of Science(PO2325).
文摘A new dynamic model for non-Fickian diffu-sion of calcium spark in cardiac myocytes was developed by introducing time lags on the basis of the microscale mass transport theory. Numerical simulation showed that the size of the calcium spark produced by the new dynamic model was larger than that of Fick diffusion and was in more agreement with experimental results. In addition, the time lags of the calcium spark in cardiac myocytes were about 0.1—0.8 ms. These results can be used to understand the mechanism of calcium spark diffusion in cardiac myocytes.