Kiwifruit (Actinidia deliciosa (A. Chev.) C. F. Liang et A. R. Ferguson cv. Bruno) was used toinvestigate the effects of acetylsalicylic acid (ASA, 1.0 mmol/L, pH 3.5) and ethylene (100 mL/L) treat-ments on changes at...Kiwifruit (Actinidia deliciosa (A. Chev.) C. F. Liang et A. R. Ferguson cv. Bruno) was used toinvestigate the effects of acetylsalicylic acid (ASA, 1.0 mmol/L, pH 3.5) and ethylene (100 mL/L) treat-ments on changes at endogenous salicylic acid (SA) levels and other senescence-related factors duringfruit ripening and softening at 20 ℃. The level of endogenous SA in ripening fruits declined and a closerelationship was observed between the change at endogenous SA level and the rate of fruit ripening andsoftening. ASA treatment elevated SA level in the fruit, slowed down the increases in lipoxygenase (LOX)and allene oxide synthase (AOS) activities, decreased the O22-. production in the preclimacteric phase andthe early phase of ethylene climacteric rise, maintained the stability of cell membrane, inhibited ethylenebiosynthesis, postponed the onset of the ethylene climacteric, and delayed the process of fruit ripeningand softening. On the contrary, application of ethylene to ripening kiwifruit resulted at a lower SA level, anaccelerated increases in the activities of LOX and AOS and the rate of O22-. production, an elevated relativeelectric conductivity and an advanced onset of ethylene climacteric, and a quicker fruit ripening andsoftening. It is suggested that the effects of ASA on ripening kiwifruit can be attributed to its ability toscavenge O22-. and/or to maintain stability of cell membrane.展开更多
Na2[VO(O2)N(CH2COO)3] · 5H2O, Mr= 423. 11, monoclinic, space group P21/c, a = 6. 283(3), b = 20. 378(6), c=12. 056(4)(?) , β=102. 96 (3)°, V = 1507. 9(?)3, Z = 4, Dc= 1. 864 g/cm3. λ(MoKα) = 0. 71069A , F...Na2[VO(O2)N(CH2COO)3] · 5H2O, Mr= 423. 11, monoclinic, space group P21/c, a = 6. 283(3), b = 20. 378(6), c=12. 056(4)(?) , β=102. 96 (3)°, V = 1507. 9(?)3, Z = 4, Dc= 1. 864 g/cm3. λ(MoKα) = 0. 71069A , F(000) = 864. Final R = 0. 037 and Rw = 0. 046 for 1658 observed reflections with I>10σ (I). The structure of the anion of the title complex shows that the vanadium atom is coordinated by one vanadyl oxygen atom, two oxygen atoms of the peroxp-group, three oxygen atoms and one nitrogen atom from the NTA ligand to form a distorted pentagonal bipyramid.展开更多
The computer molecular simulation technique was applied to study the chemisorption of thiophene and tetramethylthiophene as the model sulfides on the simple oxides and complex oxides of some transition metals as the c...The computer molecular simulation technique was applied to study the chemisorption of thiophene and tetramethylthiophene as the model sulfides on the simple oxides and complex oxides of some transition metals as the catalytic materials. The study disclosed that the thiophene sulfides could enter into chemisorption with metal oxides such as VO, ZnO, NiO and Zn-Al-spinel. This interaction could lead to thiophene molecular structure deformation to be in an activated adsorption state, which could help to promote the conversion of thiophene sulfides in the course of catalytic cracking. The VO with a valence of 2 could provide relatively strong selective adsorption sites for the conversion of thiophene sulfides to apparently transform the molecular structures and electron cloud states of such heterocyclic sulfur compounds such as thiophene and tetramethylthiophene into an activated adsorption state. The effect of this interaction was more pronounced with respect to tetramethylthiophene.展开更多
To increase the service life of rechargeable batteries,transition metal oxide hosts with high structural stability for the intercalation of carrier ions are important.Herein,we reconstruct the crystal structure of a c...To increase the service life of rechargeable batteries,transition metal oxide hosts with high structural stability for the intercalation of carrier ions are important.Herein,we reconstruct the crystal structure of a commercial V_(2)O_(5)by pre-intercalating H^(+)and H_(2)O pillars using a facile hydrothermal reaction and obtain a bi-layer structured H_(0.642)V_(2)O_(5)·0.143H_(2)O(HVO)as an excellent host for aqueous Zn-ion batteries.Benefiting from the structural reconstruction,the irreversible“layer-to-amorphous”phase evolution during cycling is considerably less,resulting in ultra-high cycling stability of HVO with nearly no capacity fading even after 500 cycles at a current density of 0.5Ag^(-1).Moreover,a synthetic proton and Zn^(2+)intercalation mechanism in the HVO host is demonstrated.This work provides both a facile synthesis method for the preparation of V-based compounds and a new viewpoint for achieving high-performance host materials.展开更多
文摘Kiwifruit (Actinidia deliciosa (A. Chev.) C. F. Liang et A. R. Ferguson cv. Bruno) was used toinvestigate the effects of acetylsalicylic acid (ASA, 1.0 mmol/L, pH 3.5) and ethylene (100 mL/L) treat-ments on changes at endogenous salicylic acid (SA) levels and other senescence-related factors duringfruit ripening and softening at 20 ℃. The level of endogenous SA in ripening fruits declined and a closerelationship was observed between the change at endogenous SA level and the rate of fruit ripening andsoftening. ASA treatment elevated SA level in the fruit, slowed down the increases in lipoxygenase (LOX)and allene oxide synthase (AOS) activities, decreased the O22-. production in the preclimacteric phase andthe early phase of ethylene climacteric rise, maintained the stability of cell membrane, inhibited ethylenebiosynthesis, postponed the onset of the ethylene climacteric, and delayed the process of fruit ripeningand softening. On the contrary, application of ethylene to ripening kiwifruit resulted at a lower SA level, anaccelerated increases in the activities of LOX and AOS and the rate of O22-. production, an elevated relativeelectric conductivity and an advanced onset of ethylene climacteric, and a quicker fruit ripening andsoftening. It is suggested that the effects of ASA on ripening kiwifruit can be attributed to its ability toscavenge O22-. and/or to maintain stability of cell membrane.
文摘Na2[VO(O2)N(CH2COO)3] · 5H2O, Mr= 423. 11, monoclinic, space group P21/c, a = 6. 283(3), b = 20. 378(6), c=12. 056(4)(?) , β=102. 96 (3)°, V = 1507. 9(?)3, Z = 4, Dc= 1. 864 g/cm3. λ(MoKα) = 0. 71069A , F(000) = 864. Final R = 0. 037 and Rw = 0. 046 for 1658 observed reflections with I>10σ (I). The structure of the anion of the title complex shows that the vanadium atom is coordinated by one vanadyl oxygen atom, two oxygen atoms of the peroxp-group, three oxygen atoms and one nitrogen atom from the NTA ligand to form a distorted pentagonal bipyramid.
文摘The computer molecular simulation technique was applied to study the chemisorption of thiophene and tetramethylthiophene as the model sulfides on the simple oxides and complex oxides of some transition metals as the catalytic materials. The study disclosed that the thiophene sulfides could enter into chemisorption with metal oxides such as VO, ZnO, NiO and Zn-Al-spinel. This interaction could lead to thiophene molecular structure deformation to be in an activated adsorption state, which could help to promote the conversion of thiophene sulfides in the course of catalytic cracking. The VO with a valence of 2 could provide relatively strong selective adsorption sites for the conversion of thiophene sulfides to apparently transform the molecular structures and electron cloud states of such heterocyclic sulfur compounds such as thiophene and tetramethylthiophene into an activated adsorption state. The effect of this interaction was more pronounced with respect to tetramethylthiophene.
基金supported by the Basic and Applied Basic Research Foundation of Guangdong Province(2019A1515110094).
文摘To increase the service life of rechargeable batteries,transition metal oxide hosts with high structural stability for the intercalation of carrier ions are important.Herein,we reconstruct the crystal structure of a commercial V_(2)O_(5)by pre-intercalating H^(+)and H_(2)O pillars using a facile hydrothermal reaction and obtain a bi-layer structured H_(0.642)V_(2)O_(5)·0.143H_(2)O(HVO)as an excellent host for aqueous Zn-ion batteries.Benefiting from the structural reconstruction,the irreversible“layer-to-amorphous”phase evolution during cycling is considerably less,resulting in ultra-high cycling stability of HVO with nearly no capacity fading even after 500 cycles at a current density of 0.5Ag^(-1).Moreover,a synthetic proton and Zn^(2+)intercalation mechanism in the HVO host is demonstrated.This work provides both a facile synthesis method for the preparation of V-based compounds and a new viewpoint for achieving high-performance host materials.
