采用体外细胞培养方法,观察茶多酚对染镍(Ni2O3,5mg/L)大鼠肺泡巨噬细胞膜脂质过氧化产物丙二醛(MDA)及超氧化物歧化酶(SOD)活性的影响。并用单细胞凝胶电泳技术(Single Cell Gel Electrophoresis, SCGE)检测三氧化二镍对人肺成纤维细胞...采用体外细胞培养方法,观察茶多酚对染镍(Ni2O3,5mg/L)大鼠肺泡巨噬细胞膜脂质过氧化产物丙二醛(MDA)及超氧化物歧化酶(SOD)活性的影响。并用单细胞凝胶电泳技术(Single Cell Gel Electrophoresis, SCGE)检测三氧化二镍对人肺成纤维细胞(HLF)的DNA损伤作用以及茶多酚的保护作用。结果显示在体外染镍大鼠肺泡巨噬细胞培养过程中加入不同浓度茶多酚(125,250和500mg/L)可提高肺泡巨噬细胞内SOD活性,且能显著抑制MDA生成量。镍处理的HLF细胞DNA损伤程度高于正常对照组(p<0.01);而Ni2O3+ 茶多酚(TP,250mg/L)处理组DNA损伤程度低于Ni组(p<0.01)。镍可增加细胞脂质过氧化,茶多酚具有拮抗镍导致细胞毒性的作用,可能与其抗氧化功能有关。茶多酚还可以拮抗镍诱导的人肺成纤维细胞DNA的损伤。展开更多
Layered P2–Na_(2/3)Ni_(1/3)Mn_(2/3)O_2 is a promising cathode material. It exhibits a high capacity and suitable operating voltage and undergoes a phase transition from P2 to O2 during charge/discharge.Researchers ha...Layered P2–Na_(2/3)Ni_(1/3)Mn_(2/3)O_2 is a promising cathode material. It exhibits a high capacity and suitable operating voltage and undergoes a phase transition from P2 to O2 during charge/discharge.Researchers have used Ti substitution to improve the cathode, yet the chemical principles that underpin elemental substitution and functional improvement remain unclear. To clarify these principles, we used in situ Raman spectroscopy to monitor chemical changes in P2–Na2/3 Ni1/3 Mn1/3 Ti1/3 O2 and P2–Na_(2/3)Ni_(1/3)Mn_(2/3)O_2 during charge/discharge. Based on the change in the A_(1g) and E_g peaks during charge/discharge, we concluded that Ti substitution compressed the transition metal layer and expanded the planar oxygen layer in the unit cell. Titanium stabilized the P2 phase structure, which improved the cycling stability of P2–NaNMT. Our results provide clear theoretical support for future research on modifying electrodes by elemental substitution.展开更多
Charging P2-Na_(2/3)Ni_(1/3)Mn_(2/3)O_(2)to 4.5 V for higher capacity is enticing.However,it leads to severe capacity fading,ascribing to the lattice oxygen evolution and the P2-O2 phase transformation.Here,the Mg Fe_...Charging P2-Na_(2/3)Ni_(1/3)Mn_(2/3)O_(2)to 4.5 V for higher capacity is enticing.However,it leads to severe capacity fading,ascribing to the lattice oxygen evolution and the P2-O2 phase transformation.Here,the Mg Fe_(2)O_(4) coating and Mg,Fe co-doping were constructed simultaneously by Mg,Fe surface treatment to suppress lattice oxygen evolution and P2-O2 phase transformation of P2-Na_(2/3)Ni_(1/3)Mn_(2/3)O_(2)at deep charging.Through ex-situ X-ray diffraction(XRD)tests,we found that the Mg,Fe bulk co-doping could reduce the repulsion between transition metals and Na+/vacancies ordering,thus inhibiting the P2-O2 phase transition and significantly reducing the irreversible volume change of the material.Meanwhile,the internal electric field formed by the dielectric polarization of Mg Fe_(2)O_(4) effectively inhibits the outward migration of oxidized O^(a-)(a<2),thereby suppressing the lattice oxygen evolution at deep charging,confirmed by in situ Raman and ex situ XPS techniques.P2-Na NM@MF-3 shows enhanced high-voltage cycling performance with capacity retentions of 84.8% and 81.3%at 0.1 and 1 C after cycles.This work sheds light on regulating the surface chemistry for Na-layered oxide materials to enhance the high-voltage performance of Na-ion batteries.展开更多
After several decades of studies of high-temperature superconductivity,there is no compelling theory for the mechanism yet;however,the spin fluctuations have been widely believed to play a crucial role in forming the ...After several decades of studies of high-temperature superconductivity,there is no compelling theory for the mechanism yet;however,the spin fluctuations have been widely believed to play a crucial role in forming the superconducting Cooper pairs.The recent discovery of high-temperature superconductivity near 80 K in the bilayer nickelate La_(3)Ni_(2)O_(7)under pressure provides a new platform to elucidate the origins of high-temperature superconductivity.We perform elastic and inelastic neutron scattering studies on a polycrystalline sample of La_(3)Ni_(2)O_(7-δ)at ambient pressure.No magnetic order can be identified down to 10 K.The absence of long-range magnetic order in neutron diffraction measurements may be ascribed to the smallness of the magnetic moment.However,we observe a weak flat spin-fluctuation signal in the inelastic scattering spectra at~45 meV.The observed spin excitations could be interpreted as a result of strong interlayer and weak intralayer magnetic couplings for stripe-type antiferromagnetic orders.Our results provide crucial information on the spin dynamics and are thus important for understanding the superconductivity in La_(3)Ni_(2)O_(7).展开更多
<001>textured Pb(Ni_(1/3)Nb_(2/3))O_(3)-PbZrO_(3)-PbTiO_(3)(PNN-PZT)ceramics were prepared by templated grain growth(TGG)technique using 0.36PNN-x PZ-(0.64-x)PT(x=0.23,0.25 and 0.27)powder matrix.Optimum templat...<001>textured Pb(Ni_(1/3)Nb_(2/3))O_(3)-PbZrO_(3)-PbTiO_(3)(PNN-PZT)ceramics were prepared by templated grain growth(TGG)technique using 0.36PNN-x PZ-(0.64-x)PT(x=0.23,0.25 and 0.27)powder matrix.Optimum template content was derived to achieve the best electromechanical properties of textured ceramics.The piezoelectric coefficient d33=1165 pC/N,Curie temperature T_(C)=197℃,longitudinal mode electrome-chanical coupling factor k33=0.86 and a very large effective piezoelectric strain coefficient d_(33)^(*)=2041 pm/V were simultaneously achieved at the morphotropic phase boundary(MPB)composition(x=0.25)with 3 vol.%BaTiO_(3)(BT)templates.Domain structures of textured ceramics were analyzed in detail to reveal the origin of these high piezoelectric and electromechanical properties.展开更多
Zinc ion hybrid supercapacitors(ZHS)have received much attention due to the enhanced potential window range and high specific capacity.However,the appropriate positive materials with high electrochemical performance a...Zinc ion hybrid supercapacitors(ZHS)have received much attention due to the enhanced potential window range and high specific capacity.However,the appropriate positive materials with high electrochemical performance are still a challenge.Herein,NH_(4)^(+)and glycerate anions pre-inserted Mo glycerate(N-MoG)spheres are synthesized and serve as the template to form NH_(4)^(+)intercalated Ni_(3)S_(2)/Ni_(3)O_(2)(OH)_(4)@MoS_(2)core–shell nanoflower(N-NiMo-OS)in-situ grown on nickel foam(NF)(N-NiMo-OS/NF)by sulfurization treatment.Compared with the product using traditional MoG as a template,N-NiMo-OS/NF inheriting a larger core structure from N-MoG delivers enhanced space for ions transport and volume expansion during the energy storage process,together with the synergistic effects of multi-components and the heterostructure,the as-prepared N-NiMo-OS/NF nanoflower exhibits excellent performance for the battery-type hybrid supercapacitors(BHS)and ZHS devices.Notably,the ZHS device delivers superior electrochemical performance to the BHS device,such as a higher specific capacity of 327.5 mAh·g^(−1)at 1 A·g^(−1),a preeminent energy density of 610.6 Wh·kg^(−1)at 1710 W·kg^(−1),long cycle life.The in-situ Raman,ex-situ X-ray photoelectron spectroscopy(XPS),theoretical calculation demonstrate the extra Zn^(2+)insertion/extraction storage mechanism provides enhanced electrochemical performance for ZHS device.Therefore,the dual-ion pre-inserted strategy can be extended for other advanced electrode materials in energy storage fields.展开更多
基金supported by the NSFC (21905239, 21925404, and 21775127)the Natural Science Foundation of Shanxi Province of China (201901D211265)the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi (2019L0609)。
文摘Layered P2–Na_(2/3)Ni_(1/3)Mn_(2/3)O_2 is a promising cathode material. It exhibits a high capacity and suitable operating voltage and undergoes a phase transition from P2 to O2 during charge/discharge.Researchers have used Ti substitution to improve the cathode, yet the chemical principles that underpin elemental substitution and functional improvement remain unclear. To clarify these principles, we used in situ Raman spectroscopy to monitor chemical changes in P2–Na2/3 Ni1/3 Mn1/3 Ti1/3 O2 and P2–Na_(2/3)Ni_(1/3)Mn_(2/3)O_2 during charge/discharge. Based on the change in the A_(1g) and E_g peaks during charge/discharge, we concluded that Ti substitution compressed the transition metal layer and expanded the planar oxygen layer in the unit cell. Titanium stabilized the P2 phase structure, which improved the cycling stability of P2–NaNMT. Our results provide clear theoretical support for future research on modifying electrodes by elemental substitution.
基金supported by the Special Project for the Central Government to Guide Local Technological Development (GUIKE ZY20198008)the Guangxi Technology Base and talent Subject (GUIKE AD20238012,AD20297086)+5 种基金the Natural Science Foundation of Guangxi Province (2021GXNSFDA075012)the National Natural Science Foundation of China (51902108,52104298,22169004)the National Natural Science Foundation of China (U20A20249)the Regional Innovation and Development Joint Fundthe Guangxi Innovation Driven Development Subject (GUIKE AA19182020,19254004)the Special Fund for Guangxi Distinguished Expert。
文摘Charging P2-Na_(2/3)Ni_(1/3)Mn_(2/3)O_(2)to 4.5 V for higher capacity is enticing.However,it leads to severe capacity fading,ascribing to the lattice oxygen evolution and the P2-O2 phase transformation.Here,the Mg Fe_(2)O_(4) coating and Mg,Fe co-doping were constructed simultaneously by Mg,Fe surface treatment to suppress lattice oxygen evolution and P2-O2 phase transformation of P2-Na_(2/3)Ni_(1/3)Mn_(2/3)O_(2)at deep charging.Through ex-situ X-ray diffraction(XRD)tests,we found that the Mg,Fe bulk co-doping could reduce the repulsion between transition metals and Na+/vacancies ordering,thus inhibiting the P2-O2 phase transition and significantly reducing the irreversible volume change of the material.Meanwhile,the internal electric field formed by the dielectric polarization of Mg Fe_(2)O_(4) effectively inhibits the outward migration of oxidized O^(a-)(a<2),thereby suppressing the lattice oxygen evolution at deep charging,confirmed by in situ Raman and ex situ XPS techniques.P2-Na NM@MF-3 shows enhanced high-voltage cycling performance with capacity retentions of 84.8% and 81.3%at 0.1 and 1 C after cycles.This work sheds light on regulating the surface chemistry for Na-layered oxide materials to enhance the high-voltage performance of Na-ion batteries.
基金supported by the National Key Research and Development Program of China(2023YFA1406500,2023YFA1406000)the National Natural Science Foundation of China(12304187,12174454,U21301001)+5 种基金the Guangdong Basic and Applied Basic Research Funds(2024B1515020040,2024A1515030030,2022A1515011618)Guangzhou Basic and Applied Basic Research Funds(202201011123,2024A04J4024,2024A04J6417)Shenzhen Science and Technology Program(RCYX20231211090245050)Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices(2022B1212010008)the Fundamental Research Funds for the Central Universities,Sun Yat-sen University(23qnpy57)the open research fund of Songshan Lake Materials Laboratory(2023SLABFN30)。
文摘After several decades of studies of high-temperature superconductivity,there is no compelling theory for the mechanism yet;however,the spin fluctuations have been widely believed to play a crucial role in forming the superconducting Cooper pairs.The recent discovery of high-temperature superconductivity near 80 K in the bilayer nickelate La_(3)Ni_(2)O_(7)under pressure provides a new platform to elucidate the origins of high-temperature superconductivity.We perform elastic and inelastic neutron scattering studies on a polycrystalline sample of La_(3)Ni_(2)O_(7-δ)at ambient pressure.No magnetic order can be identified down to 10 K.The absence of long-range magnetic order in neutron diffraction measurements may be ascribed to the smallness of the magnetic moment.However,we observe a weak flat spin-fluctuation signal in the inelastic scattering spectra at~45 meV.The observed spin excitations could be interpreted as a result of strong interlayer and weak intralayer magnetic couplings for stripe-type antiferromagnetic orders.Our results provide crucial information on the spin dynamics and are thus important for understanding the superconductivity in La_(3)Ni_(2)O_(7).
基金supported in part by the Natural Science Foun-dation of Heilongjiang Province(No.LH2022E048)Postdoctoral Science Foundation of Heilongjiang Province(No.LBH-Z22138)China National Postdoctoral Program for Innovative Talents(No.BX20490103).
文摘<001>textured Pb(Ni_(1/3)Nb_(2/3))O_(3)-PbZrO_(3)-PbTiO_(3)(PNN-PZT)ceramics were prepared by templated grain growth(TGG)technique using 0.36PNN-x PZ-(0.64-x)PT(x=0.23,0.25 and 0.27)powder matrix.Optimum template content was derived to achieve the best electromechanical properties of textured ceramics.The piezoelectric coefficient d33=1165 pC/N,Curie temperature T_(C)=197℃,longitudinal mode electrome-chanical coupling factor k33=0.86 and a very large effective piezoelectric strain coefficient d_(33)^(*)=2041 pm/V were simultaneously achieved at the morphotropic phase boundary(MPB)composition(x=0.25)with 3 vol.%BaTiO_(3)(BT)templates.Domain structures of textured ceramics were analyzed in detail to reveal the origin of these high piezoelectric and electromechanical properties.
基金the National Natural Science Foundation of China(Nos.21702116,51772162,and 52072197)the 111 Project of China(No.D20017)+5 种基金Shandong Provincial Key Research and Development Program,China(No.2019GSF107087)Qingdao Postdoctoral Sustentation Fund,Youth Innovation and Technology Foundation of Shandong Higher Education Institutions,China(No.2019KJC004)Outstanding Youth Foundation of Shandong Province,China(No.ZR2019JQ14)Taishan Scholar Young Talent Program(No.tsqn201909114)Major Scientific and Technological Innovation Project(No.2019JZZY020405)Major Basic Research Program of Natural Science Foundation of Shandong Province(No.ZR2020ZD09).
文摘Zinc ion hybrid supercapacitors(ZHS)have received much attention due to the enhanced potential window range and high specific capacity.However,the appropriate positive materials with high electrochemical performance are still a challenge.Herein,NH_(4)^(+)and glycerate anions pre-inserted Mo glycerate(N-MoG)spheres are synthesized and serve as the template to form NH_(4)^(+)intercalated Ni_(3)S_(2)/Ni_(3)O_(2)(OH)_(4)@MoS_(2)core–shell nanoflower(N-NiMo-OS)in-situ grown on nickel foam(NF)(N-NiMo-OS/NF)by sulfurization treatment.Compared with the product using traditional MoG as a template,N-NiMo-OS/NF inheriting a larger core structure from N-MoG delivers enhanced space for ions transport and volume expansion during the energy storage process,together with the synergistic effects of multi-components and the heterostructure,the as-prepared N-NiMo-OS/NF nanoflower exhibits excellent performance for the battery-type hybrid supercapacitors(BHS)and ZHS devices.Notably,the ZHS device delivers superior electrochemical performance to the BHS device,such as a higher specific capacity of 327.5 mAh·g^(−1)at 1 A·g^(−1),a preeminent energy density of 610.6 Wh·kg^(−1)at 1710 W·kg^(−1),long cycle life.The in-situ Raman,ex-situ X-ray photoelectron spectroscopy(XPS),theoretical calculation demonstrate the extra Zn^(2+)insertion/extraction storage mechanism provides enhanced electrochemical performance for ZHS device.Therefore,the dual-ion pre-inserted strategy can be extended for other advanced electrode materials in energy storage fields.
