Improving interfacial bonding and alloying design are effective strategies for enhancing mechanical properties of particle-reinforced steel matrix composites(SMCs).This study prepared SMCs with uniformly distributed T...Improving interfacial bonding and alloying design are effective strategies for enhancing mechanical properties of particle-reinforced steel matrix composites(SMCs).This study prepared SMCs with uniformly distributed TiC_(P)in matrix using master alloying method.The TiC(002)/Fe(011)interface model was established based on the orientation relationship of(011)_(Fe)//(002)_(TiC),and[100]_(Fe)//[100]_(TiC).The effects of single and co-doping of alloying elements(Mn,Cr,Mo,Ni,Cu and Si)on the interface bonding behavior of TiC/Fe in composites were investigated in conjunction with first principles.The results demonstrate that the interface between TiC and matrix is continuous and stable.Compared to the undoped TiC/Fe interface,single-doping Mn,Cr,and Mo can improve the stability of TiC/Fe interface and enhance tensile strength.Conversely,single-doping with Ni,Cu,and Si reduced the interface stability and marginally reduces tensile strength.Relative to the undoped and singly Ni-doped TiC/Fe interfaces,the co-doping Ni-Mo boosts binding energy and separation work at the TiC/Fe interface,which is conducive to the interface bonding between TiC_(P)and matrix,and thus improves the mechanical properties of composites.Thus,in the alloying design of TiC particle reinforced low-alloy SMCs,incorporating Mn,Cr,Mo,and Ni into matrix can enhance the overall mechanical properties of composites.展开更多
The segregation behavior of alloying elements X（ X = Zr,V,Cr,Mn,Mo,W,Nb,Y） on the ferrite（ 100） /TiC（ 100） interface has been investigated using first principles method,and the work of separation and interface e...The segregation behavior of alloying elements X（ X = Zr,V,Cr,Mn,Mo,W,Nb,Y） on the ferrite（ 100） /TiC（ 100） interface has been investigated using first principles method,and the work of separation and interface energy of ferrite / TiC interfaces alloyed by these elements were also analyzed. The results indicated that all these alloying additives except Y were thermodynamically favorable because of the negative segregation energy,showing that they have the tendency to segregate to the ferrite / TiC interface. When the Fe atom in the ferrite /TiC interface is replaced by Y,Zr,or Nb,the adhesive strength of the interface will be weakened due to the lower separation work,larger interfacial energy,and weaker electron effects. However,the introduction of Cr,Mo,W,Mn and V will improve the stability of the ferrite / TiC interface through strong interaction between these elements and C,and Cr-doped interface is the most stable structure. Therefore,the Cr,Mo,W,Mn and V in ferrite side of the interface can effectively promote ferrite heterogeneous nucleation on TiC surface to form fine ferrite grain.展开更多
ABSTRACT： The two basalt flows in Kupukuziman （库普库兹满） Formation of Keping （柯枰） area are the typical products of Permian magmatism. Based on systematic field investigations, we carried out geochemical studi...ABSTRACT： The two basalt flows in Kupukuziman （库普库兹满） Formation of Keping （柯枰） area are the typical products of Permian magmatism. Based on systematic field investigations, we carried out geochemical studies on representative Keping basalts. The results show that the SiO2 contents in basalts range from 44.69 wt.% to 51.68 wt.%, and the total alkalis range from 4.05 wt.% to 5.5 wt.%, belonging to alkaline basalts. The Ti/Y=468.27-565.35 and TIO2=（2.88-3.82） wt.% compared to those of the high-Ti basalts in Emeishan （峨眉山） large igneous province （LIP） （TIO2=（3.58-5.21） wt.%, Ti/Y〉500, Xiao et al., 2004）. The contents of MgO and compatible elements Cr （12.9-18.6 ppm）, Ni （13.7-22.7 ppm）, and Co （39.6-50.2 ppm） are low, which suggest that the samples have undergone varying grades of fractional crystallization. All the samples have uniform REE and other trace element characteristics, with enriched LREE and LILE relative to HREE and HFS, similar REE patterns without Eu anomaly. The basalts are also show slightly depleted of Ta and Nb. They have higher initial STSr/S6Sr ratios （0.707 211-0.708 300）, lower tNd（t） values （-2.47 to -4.14）, and a narrow range of （208pb/204pb）t=37.535 2-38.297 7, （207pb/204pb）~=15.435 7-15.517 0, and （206Pb/204pb）t=17.206 5-17.874 7 ratios. The Ce/Y versus Zr/Nb diagram shows that the parent magmas were originated from low-degree partial melting of the garnet-lherzolite. The analysis results based on geochemical studies seem all point to the same conclusion that the Keping basalts have formed as a product of the interaction between the plume-derived melts and the lithosphere.Geochemical Characteristics and Petrogenesis of Permian Basaltic Rocks in Keping Area, Western Tarim Basin展开更多
Lanthanide heteropoly compounds K15[Ln(HSiW9O34)2]·28H2O(Ln = La, Ce, Nd), denoted as Ln(SiW9)2, were synthesized and characterized by element analysis, TG-DTA, IR, UV, XPS and XRD. The results show that partial ...Lanthanide heteropoly compounds K15[Ln(HSiW9O34)2]·28H2O(Ln = La, Ce, Nd), denoted as Ln(SiW9)2, were synthesized and characterized by element analysis, TG-DTA, IR, UV, XPS and XRD. The results show that partial oxygen in Ln(SiW9)2 was coordinated with Ln3- , where Ln-3 was in the inner side of the heteropoly anions, while the fundamental structure of SiW9 had little change. The result was supported by ion exchange experiment.展开更多
Background The clinical characteristics of stroke patients treated with double anti-platelet therapy （DAPT） after percutaneous coronary intervention （PCI） is not clear. Methods In total, 2675 patients under- went ...Background The clinical characteristics of stroke patients treated with double anti-platelet therapy （DAPT） after percutaneous coronary intervention （PCI） is not clear. Methods In total, 2675 patients under- went PCI and DAPT in Guangdong General Hospital, and 68 out of them were hospitalized due to suspected stroke, of whom 23 were diagnosed as having stroke. Data of the 23 stroke patients were collected and tradi- tional risk factors associated with stroke were analyzed retrospectively. Results The mean age of these pa- tients was 75.6± 8.7 years, and 20 （87.0%） were males. Notably, 19 patients were complicated with hyper- tension, 7 with diabetes mellitus, 7 with previous history of stroke, none with atrial fibrillation （AF） or patent foramen ovale （PFO）. Specifically, 22 patients were diagnosed with ischemic stroke, and 1 patient with hemorrhagic stroke. Conclusion Stroke in patients treated with DAPT after PCI was correlated with ad- vanced age, gender, hypertension, diabetes mellitus, stroke history. Long term electrocardiography （ECG） may be needed for the diagnosis of AF, while trans-esophageal echocardiography （TEE） may be needed for PFO.展开更多
W-30 wt%Cu and TiC-50 wt%Ag were successfully synthesized by a novel simplified pretreatment followed by electroless plating.The 0 wt%TiC,0.5 wt%TiC,and 0.5 wt%TiC-0.5 wt%Ag composite powders were added to W-30 wt%Cu ...W-30 wt%Cu and TiC-50 wt%Ag were successfully synthesized by a novel simplified pretreatment followed by electroless plating.The 0 wt%TiC,0.5 wt%TiC,and 0.5 wt%TiC-0.5 wt%Ag composite powders were added to W-30 wt%Cu composite powders by blending,and then reduced.The reduced W-30 Cu,W-30 Cu/0.5 TiC,and W-30 Cu-0.5 Ag/0.5 TiC composite powders were then compacted and sintered at 1300℃in protective hydrogen for 60 min.The phase and morphology of the composite powders and materials were analyzed using X-ray diffraction and field emission scanning electron microscopy.The relative density,electrical conductivity,and hardness of the sintered samples were examined.Results showed that W-30 Cu and TiC-Ag composite powders with uniform structure were obtained using simplified pretreatment followed by electroless plating.The addition of TiC particles can significantly increase the compressive strength and hardness of the W-30 Cu composite material but decrease the electrical conductivity.Next,0.5 wt%Ag was added to prepare W-30 Cu-0.5 Ag/TiC composites with excellent electrical conductivity.The electrical conductivity of these composites(61.2%)is higher than that in the national standard(the imaginary line denotes electrical conductivity of GB IACS 42%)of 45.7%.展开更多
基金Project supported by the Special Funding Support for the Development of 1500 Meter Subsea Christmas Tree and Control System,China。
文摘Improving interfacial bonding and alloying design are effective strategies for enhancing mechanical properties of particle-reinforced steel matrix composites(SMCs).This study prepared SMCs with uniformly distributed TiC_(P)in matrix using master alloying method.The TiC(002)/Fe(011)interface model was established based on the orientation relationship of(011)_(Fe)//(002)_(TiC),and[100]_(Fe)//[100]_(TiC).The effects of single and co-doping of alloying elements(Mn,Cr,Mo,Ni,Cu and Si)on the interface bonding behavior of TiC/Fe in composites were investigated in conjunction with first principles.The results demonstrate that the interface between TiC and matrix is continuous and stable.Compared to the undoped TiC/Fe interface,single-doping Mn,Cr,and Mo can improve the stability of TiC/Fe interface and enhance tensile strength.Conversely,single-doping with Ni,Cu,and Si reduced the interface stability and marginally reduces tensile strength.Relative to the undoped and singly Ni-doped TiC/Fe interfaces,the co-doping Ni-Mo boosts binding energy and separation work at the TiC/Fe interface,which is conducive to the interface bonding between TiC_(P)and matrix,and thus improves the mechanical properties of composites.Thus,in the alloying design of TiC particle reinforced low-alloy SMCs,incorporating Mn,Cr,Mo,and Ni into matrix can enhance the overall mechanical properties of composites.
基金financially sponsored by National Natural Science Foundation of China(51304053)
文摘The segregation behavior of alloying elements X（ X = Zr,V,Cr,Mn,Mo,W,Nb,Y） on the ferrite（ 100） /TiC（ 100） interface has been investigated using first principles method,and the work of separation and interface energy of ferrite / TiC interfaces alloyed by these elements were also analyzed. The results indicated that all these alloying additives except Y were thermodynamically favorable because of the negative segregation energy,showing that they have the tendency to segregate to the ferrite / TiC interface. When the Fe atom in the ferrite /TiC interface is replaced by Y,Zr,or Nb,the adhesive strength of the interface will be weakened due to the lower separation work,larger interfacial energy,and weaker electron effects. However,the introduction of Cr,Mo,W,Mn and V will improve the stability of the ferrite / TiC interface through strong interaction between these elements and C,and Cr-doped interface is the most stable structure. Therefore,the Cr,Mo,W,Mn and V in ferrite side of the interface can effectively promote ferrite heterogeneous nucleation on TiC surface to form fine ferrite grain.
基金supported by the National 973 Program of China (Nos. 2011CB403102 and 2009CB421002)the SINOPEC Forward-Looking Project (No. YPH08114)
文摘ABSTRACT： The two basalt flows in Kupukuziman （库普库兹满） Formation of Keping （柯枰） area are the typical products of Permian magmatism. Based on systematic field investigations, we carried out geochemical studies on representative Keping basalts. The results show that the SiO2 contents in basalts range from 44.69 wt.% to 51.68 wt.%, and the total alkalis range from 4.05 wt.% to 5.5 wt.%, belonging to alkaline basalts. The Ti/Y=468.27-565.35 and TIO2=（2.88-3.82） wt.% compared to those of the high-Ti basalts in Emeishan （峨眉山） large igneous province （LIP） （TIO2=（3.58-5.21） wt.%, Ti/Y〉500, Xiao et al., 2004）. The contents of MgO and compatible elements Cr （12.9-18.6 ppm）, Ni （13.7-22.7 ppm）, and Co （39.6-50.2 ppm） are low, which suggest that the samples have undergone varying grades of fractional crystallization. All the samples have uniform REE and other trace element characteristics, with enriched LREE and LILE relative to HREE and HFS, similar REE patterns without Eu anomaly. The basalts are also show slightly depleted of Ta and Nb. They have higher initial STSr/S6Sr ratios （0.707 211-0.708 300）, lower tNd（t） values （-2.47 to -4.14）, and a narrow range of （208pb/204pb）t=37.535 2-38.297 7, （207pb/204pb）~=15.435 7-15.517 0, and （206Pb/204pb）t=17.206 5-17.874 7 ratios. The Ce/Y versus Zr/Nb diagram shows that the parent magmas were originated from low-degree partial melting of the garnet-lherzolite. The analysis results based on geochemical studies seem all point to the same conclusion that the Keping basalts have formed as a product of the interaction between the plume-derived melts and the lithosphere.Geochemical Characteristics and Petrogenesis of Permian Basaltic Rocks in Keping Area, Western Tarim Basin
文摘Lanthanide heteropoly compounds K15[Ln(HSiW9O34)2]·28H2O(Ln = La, Ce, Nd), denoted as Ln(SiW9)2, were synthesized and characterized by element analysis, TG-DTA, IR, UV, XPS and XRD. The results show that partial oxygen in Ln(SiW9)2 was coordinated with Ln3- , where Ln-3 was in the inner side of the heteropoly anions, while the fundamental structure of SiW9 had little change. The result was supported by ion exchange experiment.
文摘Background The clinical characteristics of stroke patients treated with double anti-platelet therapy （DAPT） after percutaneous coronary intervention （PCI） is not clear. Methods In total, 2675 patients under- went PCI and DAPT in Guangdong General Hospital, and 68 out of them were hospitalized due to suspected stroke, of whom 23 were diagnosed as having stroke. Data of the 23 stroke patients were collected and tradi- tional risk factors associated with stroke were analyzed retrospectively. Results The mean age of these pa- tients was 75.6± 8.7 years, and 20 （87.0%） were males. Notably, 19 patients were complicated with hyper- tension, 7 with diabetes mellitus, 7 with previous history of stroke, none with atrial fibrillation （AF） or patent foramen ovale （PFO）. Specifically, 22 patients were diagnosed with ischemic stroke, and 1 patient with hemorrhagic stroke. Conclusion Stroke in patients treated with DAPT after PCI was correlated with ad- vanced age, gender, hypertension, diabetes mellitus, stroke history. Long term electrocardiography （ECG） may be needed for the diagnosis of AF, while trans-esophageal echocardiography （TEE） may be needed for PFO.
基金Funded by the National Magnetic Confinement Fusion Program(No.2014GB121001)
文摘W-30 wt%Cu and TiC-50 wt%Ag were successfully synthesized by a novel simplified pretreatment followed by electroless plating.The 0 wt%TiC,0.5 wt%TiC,and 0.5 wt%TiC-0.5 wt%Ag composite powders were added to W-30 wt%Cu composite powders by blending,and then reduced.The reduced W-30 Cu,W-30 Cu/0.5 TiC,and W-30 Cu-0.5 Ag/0.5 TiC composite powders were then compacted and sintered at 1300℃in protective hydrogen for 60 min.The phase and morphology of the composite powders and materials were analyzed using X-ray diffraction and field emission scanning electron microscopy.The relative density,electrical conductivity,and hardness of the sintered samples were examined.Results showed that W-30 Cu and TiC-Ag composite powders with uniform structure were obtained using simplified pretreatment followed by electroless plating.The addition of TiC particles can significantly increase the compressive strength and hardness of the W-30 Cu composite material but decrease the electrical conductivity.Next,0.5 wt%Ag was added to prepare W-30 Cu-0.5 Ag/TiC composites with excellent electrical conductivity.The electrical conductivity of these composites(61.2%)is higher than that in the national standard(the imaginary line denotes electrical conductivity of GB IACS 42%)of 45.7%.
