Lithium-rich manganese-based oxides have the advantages of high discharge specific capacity, so they are potential candidates for advanced lithium battery cathode materials. However, they also have drawbacks to be sol...Lithium-rich manganese-based oxides have the advantages of high discharge specific capacity, so they are potential candidates for advanced lithium battery cathode materials. However, they also have drawbacks to be solved such as serious irreversible loss of capacity and voltage decay in the cycling process. Surface coating method was used in this paper to modify the lithium-rich manganese-based oxide(LRMO,Li_(1.2)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)) to improve its electrochemical properties. Zirconium-based compounds coated LRMO materials(ZBC@LRMO) were obtained via the reaction of lithium hydroxide with zirconium n-butanol and subsequent thermal treatment at different temperatures. The results of X-ray diffraction and transmission electron microscopy confirm that the crystal structure and composition of the ZBC coating layer vary with the calcination temperature. The coating layer obtained at 600 ℃ is composed of tetragonal ZrO_(2) and Li_(2)ZrO_(3). The ZBC@LRMO sample with tetragonal ZrO =2 and Li_(2)ZrO_(3) composite exhibits the best electrochemical performance: the discharge capacity of ZBC@LRMO can reach 296 mAh g^(-1) at 0.1 C and 120 mAh g^(-1) at high rate of 5 C.展开更多
Zirconium-based metallic glasses(Zr-MGs)are demonstrated to exhibit high mechanical strength,low elastic modulus and excellent biocompatibility,making them promising materials for endosseous implants.Meanwhile,tantalu...Zirconium-based metallic glasses(Zr-MGs)are demonstrated to exhibit high mechanical strength,low elastic modulus and excellent biocompatibility,making them promising materials for endosseous implants.Meanwhile,tantalum(Ta)is also well known for its ideal corrosion resistance and biological effects.However,the metal has an elastic modulus as high as 186 GPa which is not comparable to the natural bone(10–30 GPa),and it also has a relative high cost.Here,to fully exploit the advantages of Ta as endosseous implants,a small amount of Ta(as low as 3 at.%)was successfully added into a Zr-MG to generate an advanced functional endosseous implant,Zr58Cu25Al14Ta3 MG,with superior comprehensive properties.Upon carefully dissecting the atomic structure and surface chemistry,the results show that amorphization of Ta enables the uniform distribution in material surface,leading to a significantly improved chemical stability and extensive material-cell contact regulation.Systematical analyses on the immunological,angiogenesis and osteogenesis capability of the material are carried out utilizing the next-generation sequencing,revealing that Zr_(58)Cu_(25)Al_(14)Ta_(3)MG can regulate angiogenesis through VEGF signaling pathway and osteogenesis via BMP signaling pathway.Animal experiment further confirms a sound osseointegration of Zr_(58)Cu_(25)Al_(14)Ta_(3)MG in achieving better bone-implant-contact and inducing faster periimplant bone formation.展开更多
Zirconium-based metal-organic cages(Zr-MOCs)typically exhibit high stability,but their structural and application reports are scarce due to stringent crystallization conditions.We have successfully fluorinated the cla...Zirconium-based metal-organic cages(Zr-MOCs)typically exhibit high stability,but their structural and application reports are scarce due to stringent crystallization conditions.We have successfully fluorinated the classical Zr-MOCs(ZrT-3)for the first time,obtaining the fluorinated MOCs(ZrT-3-F).Notably,ZrT-3-F not only inherits the high stability of its parent structure,but also acts as a catalyst for the effective oxidation of benzyl thioether for the first time.The reaction can reach a conversion rate of 99%in 6 h,and the selectivity reaches 95%,which far exceeds the non-fluorinated ZrT-3.This work proves that the specific functionalization of the classical Zr-MOCs can further expand their application potential,such as catalysis.展开更多
Intermetallics and phase transformations of the zirconium-based alloy, Zr-1.0Sn-0.3Nb-0.3Fe-0.1Cr, were investigated by conventional X-ray diffraction （XRD）, differential scanning calorimetry （DSC）, and dilation m...Intermetallics and phase transformations of the zirconium-based alloy, Zr-1.0Sn-0.3Nb-0.3Fe-0.1Cr, were investigated by conventional X-ray diffraction （XRD）, differential scanning calorimetry （DSC）, and dilation measurement. Three types of precipitates, namely, （ZrNb）2Fe, Zr（CrFe）2, and Zr3Fe, were detected by XRD. The cubic Ti2Ni-type （ZrNb）2Fe was found to be the main precipitate in the alloy, and it was proposed to dissolve at 861℃, whereas Zr3Fe dissolved at 780℃ and Zr（CrFe）2 at 814℃. No precipitates were observed at a temperature higher than 900℃. The transformation-start temperature of α-Zr → β-Zr was reconfirmed to be 780℃, and the end temperature of α-Zr →βZr was determined to be 955℃. The dilation result also revealed that the martensitic transformation-start temperature, Ms, and the finish temperature, Mf, of this alloy were 741℃ and 645℃, respectively.展开更多
Glass-forming ability（GFA） and mechanical properties of（Zr_（0.58）Nb_（0.03）Cu_（0.16）Ni_（0.13）Al_（0.10））_（100-x）Lu_x（x= 0-3 at%） alloys have been investigated.The GFA of Zr_（58）Nb_3Cu_（16）Ni_（13）...Glass-forming ability（GFA） and mechanical properties of（Zr_（0.58）Nb_（0.03）Cu_（0.16）Ni_（0.13）Al_（0.10））_（100-x）Lu_x（x= 0-3 at%） alloys have been investigated.The GFA of Zr_（58）Nb_3Cu_（16）Ni_（13）Al_（10） alloy is dramatically enhanced by adding Lu.The（Zr_（0.58）Nb_（0.03）Cu_（0.16）Ni_（0.13）Al_（0.10））_（98）Lu_2 alloy possesses the highest GFA in the studied Zr-Nb-Cu-Ni-Al-Lu alloys,with its critical diameter for glass formation reaching 20 mm by copper-mould casting method,while that of the Lu-free Zr_（58）Nb_3Cu_（16）Ni_（13）Al_（10） alloy is 7 mm.The critical diameters of（Zr_（0.58）Nb_（0.03）Cu_（0.16）Ni_（0.13）Al_（0.10））_（100-x）Lu_x（x =1 at%and 3 at%） alloys are 15 mm and 12 mm,respectively.The Lu addition to Zr_（58）Nb_3Cu_（16）Ni_（13）Al_（10） alloy induces the change of initial crystallization phases from face-centred-cubic Zr_2Ni and tetragonal Zr_2Ni phases for the Lu-free Zr_（58）Nb_3Cu_（16）Ni_（13）Al_（10） alloy to an icosahedral quasi-crystalline phase for the Lu-doped alloys,which may be the origin for the enhanced GFA of the Lu-doped alloys.The compressive fracture strength and plastic strain of the bulk glassy（Zr_（0.58）Nb_（0.03）Cu_（0.16）Ni_（0.13）Al_（0.10））_（98）Lu_2 alloy are1 610 MPa and 1.5%,respectively.展开更多
A Zr-1.15wt% Cr-0.10wt% Fe alloy was beta-quenched from 1050℃ to produce a supersaturated α′-phase, and then heated for varying times at temperatures from 650℃ to 760℃ to precipitate Zr(CrFe)_2.A thermoelectric p...A Zr-1.15wt% Cr-0.10wt% Fe alloy was beta-quenched from 1050℃ to produce a supersaturated α′-phase, and then heated for varying times at temperatures from 650℃ to 760℃ to precipitate Zr(CrFe)_2.A thermoelectric power(TEP)technique and transmission electron microscopy(TEM)were used to monitor this precipitation process.Using the Johnson-Mehl-Avrami equation,the TEP results and a line regression method,the activation energy for diffusion and the diffusion coefficient of chromium(and Fe)in α-Zr have been calculated over 650℃～760℃.The temperature dependence of the diffusion coefficient,D_(Cr/α)(cm^2/s)is described at 650℃～760℃ by the relationship formula.The coarsening of the Zr(CrFe)_2 particles shows a t^(1/2)dependence of mean particle size on aging time,t.Such a time dependence is typical of coarsening where atom transfer across the interface is rate-controlling.展开更多
基金supported by the National Natural Science Foundation of China(No.21776051)the Research Fund Program of Key Laboratory of Fuel Cell Technology of Guangdong Province。
文摘Lithium-rich manganese-based oxides have the advantages of high discharge specific capacity, so they are potential candidates for advanced lithium battery cathode materials. However, they also have drawbacks to be solved such as serious irreversible loss of capacity and voltage decay in the cycling process. Surface coating method was used in this paper to modify the lithium-rich manganese-based oxide(LRMO,Li_(1.2)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)) to improve its electrochemical properties. Zirconium-based compounds coated LRMO materials(ZBC@LRMO) were obtained via the reaction of lithium hydroxide with zirconium n-butanol and subsequent thermal treatment at different temperatures. The results of X-ray diffraction and transmission electron microscopy confirm that the crystal structure and composition of the ZBC coating layer vary with the calcination temperature. The coating layer obtained at 600 ℃ is composed of tetragonal ZrO_(2) and Li_(2)ZrO_(3). The ZBC@LRMO sample with tetragonal ZrO =2 and Li_(2)ZrO_(3) composite exhibits the best electrochemical performance: the discharge capacity of ZBC@LRMO can reach 296 mAh g^(-1) at 0.1 C and 120 mAh g^(-1) at high rate of 5 C.
基金supported by the National Natural Science Foundation of China(52035001)National Key R&D Program of China(2019YFB1706904)+3 种基金Beijing Training Project for the Leading Talents in S&T(Z191100006119022)National Key Research and Development Plan(2018YFA0703603)National Science 535 Foundation of China(52192602)Youth Fund of the National Natural Science Foundation of China(82201125).
文摘Zirconium-based metallic glasses(Zr-MGs)are demonstrated to exhibit high mechanical strength,low elastic modulus and excellent biocompatibility,making them promising materials for endosseous implants.Meanwhile,tantalum(Ta)is also well known for its ideal corrosion resistance and biological effects.However,the metal has an elastic modulus as high as 186 GPa which is not comparable to the natural bone(10–30 GPa),and it also has a relative high cost.Here,to fully exploit the advantages of Ta as endosseous implants,a small amount of Ta(as low as 3 at.%)was successfully added into a Zr-MG to generate an advanced functional endosseous implant,Zr58Cu25Al14Ta3 MG,with superior comprehensive properties.Upon carefully dissecting the atomic structure and surface chemistry,the results show that amorphization of Ta enables the uniform distribution in material surface,leading to a significantly improved chemical stability and extensive material-cell contact regulation.Systematical analyses on the immunological,angiogenesis and osteogenesis capability of the material are carried out utilizing the next-generation sequencing,revealing that Zr_(58)Cu_(25)Al_(14)Ta_(3)MG can regulate angiogenesis through VEGF signaling pathway and osteogenesis via BMP signaling pathway.Animal experiment further confirms a sound osseointegration of Zr_(58)Cu_(25)Al_(14)Ta_(3)MG in achieving better bone-implant-contact and inducing faster periimplant bone formation.
基金supported by National Natural Science Foundation of China(Nos.22201046,22371054)Local Innovation Research Team Project of Guangdong Pearl River Talent Plan(No.2017BT01Z032)。
文摘Zirconium-based metal-organic cages(Zr-MOCs)typically exhibit high stability,but their structural and application reports are scarce due to stringent crystallization conditions.We have successfully fluorinated the classical Zr-MOCs(ZrT-3)for the first time,obtaining the fluorinated MOCs(ZrT-3-F).Notably,ZrT-3-F not only inherits the high stability of its parent structure,but also acts as a catalyst for the effective oxidation of benzyl thioether for the first time.The reaction can reach a conversion rate of 99%in 6 h,and the selectivity reaches 95%,which far exceeds the non-fluorinated ZrT-3.This work proves that the specific functionalization of the classical Zr-MOCs can further expand their application potential,such as catalysis.
基金the Foundation of Key Laboratory of National Defense Technologythe National Key Laboratory for Nuclear Fuel and Materials (No. 00JS85.9.1GX0101)the Science Foundation of Guangxi Province, China (Nos. 0448022 and 0728060)
文摘Intermetallics and phase transformations of the zirconium-based alloy, Zr-1.0Sn-0.3Nb-0.3Fe-0.1Cr, were investigated by conventional X-ray diffraction （XRD）, differential scanning calorimetry （DSC）, and dilation measurement. Three types of precipitates, namely, （ZrNb）2Fe, Zr（CrFe）2, and Zr3Fe, were detected by XRD. The cubic Ti2Ni-type （ZrNb）2Fe was found to be the main precipitate in the alloy, and it was proposed to dissolve at 861℃, whereas Zr3Fe dissolved at 780℃ and Zr（CrFe）2 at 814℃. No precipitates were observed at a temperature higher than 900℃. The transformation-start temperature of α-Zr → β-Zr was reconfirmed to be 780℃, and the end temperature of α-Zr →βZr was determined to be 955℃. The dilation result also revealed that the martensitic transformation-start temperature, Ms, and the finish temperature, Mf, of this alloy were 741℃ and 645℃, respectively.
基金Funded by the National Natural Science Foundation of China(Nos.51101133,51101134)the Encouraging Foundation for Outstanding Youth Scientists of Shandong Province,China(No.BS2012CL036)the Natural Science Foundation of Shandong Province,China(No.ZR2011EL025)
文摘Glass-forming ability（GFA） and mechanical properties of（Zr_（0.58）Nb_（0.03）Cu_（0.16）Ni_（0.13）Al_（0.10））_（100-x）Lu_x（x= 0-3 at%） alloys have been investigated.The GFA of Zr_（58）Nb_3Cu_（16）Ni_（13）Al_（10） alloy is dramatically enhanced by adding Lu.The（Zr_（0.58）Nb_（0.03）Cu_（0.16）Ni_（0.13）Al_（0.10））_（98）Lu_2 alloy possesses the highest GFA in the studied Zr-Nb-Cu-Ni-Al-Lu alloys,with its critical diameter for glass formation reaching 20 mm by copper-mould casting method,while that of the Lu-free Zr_（58）Nb_3Cu_（16）Ni_（13）Al_（10） alloy is 7 mm.The critical diameters of（Zr_（0.58）Nb_（0.03）Cu_（0.16）Ni_（0.13）Al_（0.10））_（100-x）Lu_x（x =1 at%and 3 at%） alloys are 15 mm and 12 mm,respectively.The Lu addition to Zr_（58）Nb_3Cu_（16）Ni_（13）Al_（10） alloy induces the change of initial crystallization phases from face-centred-cubic Zr_2Ni and tetragonal Zr_2Ni phases for the Lu-free Zr_（58）Nb_3Cu_（16）Ni_（13）Al_（10） alloy to an icosahedral quasi-crystalline phase for the Lu-doped alloys,which may be the origin for the enhanced GFA of the Lu-doped alloys.The compressive fracture strength and plastic strain of the bulk glassy（Zr_（0.58）Nb_（0.03）Cu_（0.16）Ni_（0.13）Al_（0.10））_（98）Lu_2 alloy are1 610 MPa and 1.5%,respectively.
文摘A Zr-1.15wt% Cr-0.10wt% Fe alloy was beta-quenched from 1050℃ to produce a supersaturated α′-phase, and then heated for varying times at temperatures from 650℃ to 760℃ to precipitate Zr(CrFe)_2.A thermoelectric power(TEP)technique and transmission electron microscopy(TEM)were used to monitor this precipitation process.Using the Johnson-Mehl-Avrami equation,the TEP results and a line regression method,the activation energy for diffusion and the diffusion coefficient of chromium(and Fe)in α-Zr have been calculated over 650℃～760℃.The temperature dependence of the diffusion coefficient,D_(Cr/α)(cm^2/s)is described at 650℃～760℃ by the relationship formula.The coarsening of the Zr(CrFe)_2 particles shows a t^(1/2)dependence of mean particle size on aging time,t.Such a time dependence is typical of coarsening where atom transfer across the interface is rate-controlling.
