Using rolling-ploughing-extrusion compound processing methods,a 3D integral-fin structure on outside surface of red copper tube with diameter of 16.0 mm and wall thickness of 1.5 mm was obtained. When both rolling dep...Using rolling-ploughing-extrusion compound processing methods,a 3D integral-fin structure on outside surface of red copper tube with diameter of 16.0 mm and wall thickness of 1.5 mm was obtained. When both rolling depth and ploughing-extrusion(P-E) depth were 0.2 mm,rotating speed was 50 r/min,feed speed was 0.16 mm/r,3D fin structures with height of 0.25 mm were gotten. Two different fin structures were obtained in grooves formed with rolling-ploughing-extrusion compound forming technology and observed by scanning electron microscope(SEM). One is the compound structure with V-shaped groove and U-shaped groove,and the other is the single structure with V-shaped grooves. Two kinds of groove structures obtained by rolling processing and ploughing extrusion processing are restricted together by groove interval and rolling depth,and pitch and P-E depth,respectively. Based on the analysis of interaction of rolling and P-E processing,it is found from the result that the outside 3D integral-fin can be achieved by rolling-ploughing-extrusion compound processing when single V-shaped groove structures are formed by both rolling and P-E processing.展开更多
In this article, the functions of D-myo-inositol-1,4,5-trisphosphate (Ins [1,4,5] P3) in regulating pollen tube polar growth were investigated by application of caged version of the phosphoinositides. To increase the ...In this article, the functions of D-myo-inositol-1,4,5-trisphosphate (Ins [1,4,5] P3) in regulating pollen tube polar growth were investigated by application of caged version of the phosphoinositides. To increase the intracellular Ins（1,4,5）P3 concentration at the apical region of pollen tube, the caged Ins（1,4,5）P3 loaded by osmotic shock was activated by 10 s 360 nm UV flash at this domain （10 μm from the tip）. More than 70% pollen tubes were induced swelling at apex and/or growth axis reorientation, accompanying temporarily growth arrest, by localized increase of Ins（1,4,5）P3 concentration （n=21）. While, pollen tubes without being loaded with caged Ins（1,4,5）P3 had not response to the same dosage UV flash. With FM 1-43 fluorescent staining, it was found that growth perturbation by UV activated caged Ins（1,4,5）P3 had tight link with membrane trafficking at the apical zone of pollen tubes. Upon UV pulse, the apical V-shaped bright area where was full of secretory vesicles spread to a much broader region, which implied that actin filaments at the apical region were remodeled. It was also observed that the FM 1-43 fluorescence intensity at tip remarkably increased than that before UV flash, which demonstrated that more secretory vesicles were accumulated at this region. To estimate the role of Ins（1,4,5）P3 in modulating intracellular calcium concentration and distribution, dextran conjugated fluorescent dye Calcium Green-1 and Rhodamine B were microinjected into pollen tubes together with caged Ins（1,4,5）P3. The results showed that calcium concentration at the subapical region increased upon UV released Ins（1,4,5）P3. Consequently, the tip-focused calcium gradient under the apical dome of pollen tube was disturbed. Simultaneously, the pollen tube bulged at the apical region and its growth rate decreased. As the tip-focused calcium gradient was reestablished, the pollen tube morphology and growth recovered to the normal level. Therefore, Ins（1,4,5）P3 can modulate pollen tube growth rate and direction through mobilizing intracellular calcium and regulating vesicle trafficking during pollen tube finding its way to the ovary.展开更多
Effects of Ca2+ and Mg2+ on the CO2 corrosion behaviors of tube steel were studied in simulated oil-field environment.The influence of Ca2+and Mg2+ on the corrosion rate and morphologies of corrosion product layer was...Effects of Ca2+ and Mg2+ on the CO2 corrosion behaviors of tube steel were studied in simulated oil-field environment.The influence of Ca2+and Mg2+ on the corrosion rate and morphologies of corrosion product layer was determined by scanning electron microscope and measuring mass loss.Potentiodynamic polarization and impedance spectroscopy were used to investigate the change of electrochemical characteristic parameters of corrosion product layer and corrosion dynamic process.The results show that with Ca2+ and Mg2+ in electrolyte,the morphologies and microstructures of corrosion product layer changed obviously,thus affecting the corrosion process.展开更多
Stress corrosion cracking （SCC） behavior of P 110 tubing steel in simulated C02 injection well annulus environments was investigated through three-point bent tests, potentiodynamic polarization and EIS measurements....Stress corrosion cracking （SCC） behavior of P 110 tubing steel in simulated C02 injection well annulus environments was investigated through three-point bent tests, potentiodynamic polarization and EIS measurements. The results demonstrate that SCC of P110 tubing steel could occur in acidulous simulated environment, and the sensitivity of SCC increases with the decrease ofpH, as well as increase of sulfide concentration and total environmental pressure. Both anodic dissolution and hydrogen embrittlement make contributions to the SCC. Adequate concentration of corrosion inhibitor can inhibit the occurrence of SCC on account of the inhibition of localized anodic dissolution and cathodic hydrogen evolution.展开更多
基金Projects(50436010, 50675070) supported by the National Natural Science Foundation of ChinaProject(07118064) supported by the Natural Science Foundation of Guangdong Province, China
文摘Using rolling-ploughing-extrusion compound processing methods,a 3D integral-fin structure on outside surface of red copper tube with diameter of 16.0 mm and wall thickness of 1.5 mm was obtained. When both rolling depth and ploughing-extrusion(P-E) depth were 0.2 mm,rotating speed was 50 r/min,feed speed was 0.16 mm/r,3D fin structures with height of 0.25 mm were gotten. Two different fin structures were obtained in grooves formed with rolling-ploughing-extrusion compound forming technology and observed by scanning electron microscope(SEM). One is the compound structure with V-shaped groove and U-shaped groove,and the other is the single structure with V-shaped grooves. Two kinds of groove structures obtained by rolling processing and ploughing extrusion processing are restricted together by groove interval and rolling depth,and pitch and P-E depth,respectively. Based on the analysis of interaction of rolling and P-E processing,it is found from the result that the outside 3D integral-fin can be achieved by rolling-ploughing-extrusion compound processing when single V-shaped groove structures are formed by both rolling and P-E processing.
文摘In this article, the functions of D-myo-inositol-1,4,5-trisphosphate (Ins [1,4,5] P3) in regulating pollen tube polar growth were investigated by application of caged version of the phosphoinositides. To increase the intracellular Ins（1,4,5）P3 concentration at the apical region of pollen tube, the caged Ins（1,4,5）P3 loaded by osmotic shock was activated by 10 s 360 nm UV flash at this domain （10 μm from the tip）. More than 70% pollen tubes were induced swelling at apex and/or growth axis reorientation, accompanying temporarily growth arrest, by localized increase of Ins（1,4,5）P3 concentration （n=21）. While, pollen tubes without being loaded with caged Ins（1,4,5）P3 had not response to the same dosage UV flash. With FM 1-43 fluorescent staining, it was found that growth perturbation by UV activated caged Ins（1,4,5）P3 had tight link with membrane trafficking at the apical zone of pollen tubes. Upon UV pulse, the apical V-shaped bright area where was full of secretory vesicles spread to a much broader region, which implied that actin filaments at the apical region were remodeled. It was also observed that the FM 1-43 fluorescence intensity at tip remarkably increased than that before UV flash, which demonstrated that more secretory vesicles were accumulated at this region. To estimate the role of Ins（1,4,5）P3 in modulating intracellular calcium concentration and distribution, dextran conjugated fluorescent dye Calcium Green-1 and Rhodamine B were microinjected into pollen tubes together with caged Ins（1,4,5）P3. The results showed that calcium concentration at the subapical region increased upon UV released Ins（1,4,5）P3. Consequently, the tip-focused calcium gradient under the apical dome of pollen tube was disturbed. Simultaneously, the pollen tube bulged at the apical region and its growth rate decreased. As the tip-focused calcium gradient was reestablished, the pollen tube morphology and growth recovered to the normal level. Therefore, Ins（1,4,5）P3 can modulate pollen tube growth rate and direction through mobilizing intracellular calcium and regulating vesicle trafficking during pollen tube finding its way to the ovary.
基金Item Sponsored by National Natural Science Foundation of China(50231020)National Key Fundamental Research and Development Project of China(G1999065004)
文摘Effects of Ca2+ and Mg2+ on the CO2 corrosion behaviors of tube steel were studied in simulated oil-field environment.The influence of Ca2+and Mg2+ on the corrosion rate and morphologies of corrosion product layer was determined by scanning electron microscope and measuring mass loss.Potentiodynamic polarization and impedance spectroscopy were used to investigate the change of electrochemical characteristic parameters of corrosion product layer and corrosion dynamic process.The results show that with Ca2+ and Mg2+ in electrolyte,the morphologies and microstructures of corrosion product layer changed obviously,thus affecting the corrosion process.
基金Project(2012AA040105)supported by the High-tech Research and Development Program of ChinaProject(2014CB643300)supported by National Basic Research Program of ChinaProject(51741034)supported by National Natural Science Foundation of China
文摘Stress corrosion cracking （SCC） behavior of P 110 tubing steel in simulated C02 injection well annulus environments was investigated through three-point bent tests, potentiodynamic polarization and EIS measurements. The results demonstrate that SCC of P110 tubing steel could occur in acidulous simulated environment, and the sensitivity of SCC increases with the decrease ofpH, as well as increase of sulfide concentration and total environmental pressure. Both anodic dissolution and hydrogen embrittlement make contributions to the SCC. Adequate concentration of corrosion inhibitor can inhibit the occurrence of SCC on account of the inhibition of localized anodic dissolution and cathodic hydrogen evolution.
