The surface morphology, cross-sections, and joint break force（JBF） of joints welded under different electrode forces were studied. The defects, such as electrode sticking, notch, and excessive expulsions, were obser...The surface morphology, cross-sections, and joint break force（JBF） of joints welded under different electrode forces were studied. The defects, such as electrode sticking, notch, and excessive expulsions, were observed in the joints. No desirable joints were achieved with the consideration of weld geometries and joint performances. From the cross-sectional morphology, the joint evolution during the RMW of Pt alloy and 316 LVM SS wires was developed, which involved cold collapse and heat promoted set-down of Pt alloy wire, unbalanced heating at interface, molten phase squeezed out, and defect formation. Finally, the defect formation was also discussed.展开更多
Lacustrine turbidite of Chang-7 Member in the studied area consists of sihstone and fine sandstone with respect to grain size, which is feldspathic lithie sandstone, syrosem arkose and arkose with respect to mineral c...Lacustrine turbidite of Chang-7 Member in the studied area consists of sihstone and fine sandstone with respect to grain size, which is feldspathic lithie sandstone, syrosem arkose and arkose with respect to mineral constitution affected by provenance. There are such apparent signatures as lithology, sedimentary structure, sedimentary sequence and well logs, to recognize turbidite. During the paleogeographic evolution of Chang-7 Member, lake basin and deep lake are both at their maximum extent during Chang-73 stage, resulting in the deposition of Zhangjiatan shale with widespread extent and of turbidite with fragmental-like. Deep lake line is gradually moving toward lake center and turbidite sand bodies are gradually turning better with better lateral continuity, connectivity and more thickness, from stages of Chang-73, Chang-72 and Chang-7t, which can be favorable reservoir in deep-water.展开更多
The bicyclic cryptand 1,4,7, 10,13,16,21, 24-octaaza-bigcyclo [8, 8,8] hexacosan-3, 8, 12, 17, 20, 25-hex-one (COBH) bearing diaminoethane groups along the eight-atom bridges was synthesized. The structure consists of...The bicyclic cryptand 1,4,7, 10,13,16,21, 24-octaaza-bigcyclo [8, 8,8] hexacosan-3, 8, 12, 17, 20, 25-hex-one (COBH) bearing diaminoethane groups along the eight-atom bridges was synthesized. The structure consists of discrete neutral macrobicyclic units; the two cycles share the two tertiary amine nitrogen atoms, which exhibit an endo-cndo conformation. Three identical branches formed by 1, 2-diaminoethane link the two tertiary amine groups. The protonation reactions of cryptand (COBH) and its complex formation with copper (II) were investigated by potentiometry in water and in a DMSO/water (80:20 in mass ratio) mixture as solvents. The cryptand acts as a his-base through its two N-bridgehead and exhibits a strong cooperativity that favors the first protonation and makes the second one difficult (△pK= 5.0). An inward rotation of the amide groups to form hydrogen bonds accounts for this cooperativity. The interaction of COBH with copper (II) leads to several binuclear complex proton contents.展开更多
C_(24)tetracyclic terpanes are common compounds in source rocks and crude oils,and C_(24)17,21-secohopane is the most common and widely used source-related indicator.In this study,three unusual C_(24)tetracyclic terpa...C_(24)tetracyclic terpanes are common compounds in source rocks and crude oils,and C_(24)17,21-secohopane is the most common and widely used source-related indicator.In this study,three unusual C_(24)tetracyclic terpanes were detected on the m/z 191 chromatogram of saturated hydrocarbons in the Shahejie Formation source rocks in the Bozhong subbasin.Based on the mass spectra characteristics,diagnostic ion fragments,retention time and comparisons with published literature,three unusual C_(24)tetracyclic terpanes were identified as 10β(H)-des-A-oleanane,10β(H)-des-A-lupane and C_(24)des-Ahopane.To the best of our knowledge,this is the first study to detect and publicly report these three compounds in source rock samples from the Shahejie Formation of the Bozhong subbasin,Bohai Bay Basin.The results indicated that 10β(H)-des-A-oleanane and 10β(H)-des-A-lupane likely originated from terre strial angiosperms,while C_(24)des-A-hopane likely originated fro m prokaryotic o rganisms.Te rrestrial angiosperms provide the material basis for the generation of compounds A and B,and the distribution and concentration of these two compounds are affected by thermal maturity.In the low maturity stage(0.5%<R_(0)<0.7%),compounds A and B are relatively enriched in the source rocks.展开更多
Using geometry optimization and DFT method at the B3LYP/6-31G* level for C20H10, an equilibrium geometry is identified to have the form of polyhedral hydrocarbon with five carbon-carbon single bonds linking two pentap...Using geometry optimization and DFT method at the B3LYP/6-31G* level for C20H10, an equilibrium geometry is identified to have the form of polyhedral hydrocarbon with five carbon-carbon single bonds linking two pentaprismane cages. Thus, C20H10 is a tri-cage molecule with three pentaprismane cages. Vibrational frequencies and infrared spectrum are computed at the same level. The heat of formation for this molecule has also been estimated in this paper.展开更多
The Mg65Cu25Y10 melts were quenched at a temperature of 973 K under various pressures in the range of 2-5 GPa and ambient pressure. The microstructure of the solidified specimens has been investigated by X-ray diffrac...The Mg65Cu25Y10 melts were quenched at a temperature of 973 K under various pressures in the range of 2-5 GPa and ambient pressure. The microstructure of the solidified specimens has been investigated by X-ray diffraction, transmission electron microscope and electron probe microanalysis. Experimental results show that the pressure has a great influence on the solidification microstructure of the Mg65Cu25Y10. At ambient pressure, the solidification products are Mg2(Cu,Y) and a very small amount of Y2O3 inclusion. As the pressure is above 2 GPa, a new Cu2(Y,Mg) phase appears, while Y2O3 is not observed at the pressure of 3, 4 and 5 GPa. When the pressure increases from 2 GPa to 5 GPa, the grain sizes of Mg2(Cu,Y) and Cu2(Y,Mg) decrease from 125, 96 nm to 80, 7 nm, respectively. The mechanisms for the effects of the pressure on the phase evolution and microstructure during solidification process of Mg65Cu25Y10 alloy have been discussed.展开更多
基金Funded by the National Natural Science Foundation of China(No.51365044)the State Key Laboratory for Mechanical Behavior of Materials(No.20111203)the State Key Laboratory of Advanced Welding and Joining,Harbin Institute of Technology(No.AWJ-M13-09)
文摘The surface morphology, cross-sections, and joint break force（JBF） of joints welded under different electrode forces were studied. The defects, such as electrode sticking, notch, and excessive expulsions, were observed in the joints. No desirable joints were achieved with the consideration of weld geometries and joint performances. From the cross-sectional morphology, the joint evolution during the RMW of Pt alloy and 316 LVM SS wires was developed, which involved cold collapse and heat promoted set-down of Pt alloy wire, unbalanced heating at interface, molten phase squeezed out, and defect formation. Finally, the defect formation was also discussed.
文摘Lacustrine turbidite of Chang-7 Member in the studied area consists of sihstone and fine sandstone with respect to grain size, which is feldspathic lithie sandstone, syrosem arkose and arkose with respect to mineral constitution affected by provenance. There are such apparent signatures as lithology, sedimentary structure, sedimentary sequence and well logs, to recognize turbidite. During the paleogeographic evolution of Chang-7 Member, lake basin and deep lake are both at their maximum extent during Chang-73 stage, resulting in the deposition of Zhangjiatan shale with widespread extent and of turbidite with fragmental-like. Deep lake line is gradually moving toward lake center and turbidite sand bodies are gradually turning better with better lateral continuity, connectivity and more thickness, from stages of Chang-73, Chang-72 and Chang-7t, which can be favorable reservoir in deep-water.
基金the National Natural Science Foundation of China (No.29875018) and the Natural Science Foundation of Gansu Province (ZS991-A25-
文摘The bicyclic cryptand 1,4,7, 10,13,16,21, 24-octaaza-bigcyclo [8, 8,8] hexacosan-3, 8, 12, 17, 20, 25-hex-one (COBH) bearing diaminoethane groups along the eight-atom bridges was synthesized. The structure consists of discrete neutral macrobicyclic units; the two cycles share the two tertiary amine nitrogen atoms, which exhibit an endo-cndo conformation. Three identical branches formed by 1, 2-diaminoethane link the two tertiary amine groups. The protonation reactions of cryptand (COBH) and its complex formation with copper (II) were investigated by potentiometry in water and in a DMSO/water (80:20 in mass ratio) mixture as solvents. The cryptand acts as a his-base through its two N-bridgehead and exhibits a strong cooperativity that favors the first protonation and makes the second one difficult (△pK= 5.0). An inward rotation of the amide groups to form hydrogen bonds accounts for this cooperativity. The interaction of COBH with copper (II) leads to several binuclear complex proton contents.
基金supported by open fund of Key Laboratory of Exploration Technologies for Oil and Gas Resources(Yangtze University),Ministry of Education,No.K2021-13China Postdoctoral Science Foundation(2021M692751)Tianjin branch of CNOOC(CCL2020TJT0NST1956)。
文摘C_(24)tetracyclic terpanes are common compounds in source rocks and crude oils,and C_(24)17,21-secohopane is the most common and widely used source-related indicator.In this study,three unusual C_(24)tetracyclic terpanes were detected on the m/z 191 chromatogram of saturated hydrocarbons in the Shahejie Formation source rocks in the Bozhong subbasin.Based on the mass spectra characteristics,diagnostic ion fragments,retention time and comparisons with published literature,three unusual C_(24)tetracyclic terpanes were identified as 10β(H)-des-A-oleanane,10β(H)-des-A-lupane and C_(24)des-Ahopane.To the best of our knowledge,this is the first study to detect and publicly report these three compounds in source rock samples from the Shahejie Formation of the Bozhong subbasin,Bohai Bay Basin.The results indicated that 10β(H)-des-A-oleanane and 10β(H)-des-A-lupane likely originated from terre strial angiosperms,while C_(24)des-A-hopane likely originated fro m prokaryotic o rganisms.Te rrestrial angiosperms provide the material basis for the generation of compounds A and B,and the distribution and concentration of these two compounds are affected by thermal maturity.In the low maturity stage(0.5%<R_(0)<0.7%),compounds A and B are relatively enriched in the source rocks.
基金This work was supported by the Natural Science Foundation of Shandong Province (Y2002G11)
文摘Using geometry optimization and DFT method at the B3LYP/6-31G* level for C20H10, an equilibrium geometry is identified to have the form of polyhedral hydrocarbon with five carbon-carbon single bonds linking two pentaprismane cages. Thus, C20H10 is a tri-cage molecule with three pentaprismane cages. Vibrational frequencies and infrared spectrum are computed at the same level. The heat of formation for this molecule has also been estimated in this paper.
基金supported by the National Natural Science Foundation of China(Grant number:50071060)the National Development Project for Basic Scientific Research(Grant number:G2000067201).
文摘The Mg65Cu25Y10 melts were quenched at a temperature of 973 K under various pressures in the range of 2-5 GPa and ambient pressure. The microstructure of the solidified specimens has been investigated by X-ray diffraction, transmission electron microscope and electron probe microanalysis. Experimental results show that the pressure has a great influence on the solidification microstructure of the Mg65Cu25Y10. At ambient pressure, the solidification products are Mg2(Cu,Y) and a very small amount of Y2O3 inclusion. As the pressure is above 2 GPa, a new Cu2(Y,Mg) phase appears, while Y2O3 is not observed at the pressure of 3, 4 and 5 GPa. When the pressure increases from 2 GPa to 5 GPa, the grain sizes of Mg2(Cu,Y) and Cu2(Y,Mg) decrease from 125, 96 nm to 80, 7 nm, respectively. The mechanisms for the effects of the pressure on the phase evolution and microstructure during solidification process of Mg65Cu25Y10 alloy have been discussed.
