As bifunctional oxygen evolution/reduction electrocatalysts,transition-metal-based single-atom-doped nitrogen-carbon(NC)matrices are promising successors of the corresponding noblemetal-based catalysts,offering the ad...As bifunctional oxygen evolution/reduction electrocatalysts,transition-metal-based single-atom-doped nitrogen-carbon(NC)matrices are promising successors of the corresponding noblemetal-based catalysts,offering the advantages of ultrahigh atom utilization effciency and surface active energy.However,the fabrication of such matrices(e.g.,well-dispersed single-atom-doped M-N4/NCs)often requires numerous steps and tedious processes.Herein,ultrasonic plasma engineering allows direct carbonization in a precursor solution containing metal phthalocyanine and aniline.When combining with the dispersion effect of ultrasonic waves,we successfully fabricated uniform single-atom M-N4(M=Fe,Co)carbon catalysts with a production rate as high as 10 mg min-1.The Co-N4/NC presented a bifunctional potential drop ofΔE=0.79 V,outperforming the benchmark Pt/C-Ru/C catalyst(ΔE=0.88 V)at the same catalyst loading.Theoretical calculations revealed that Co-N4 was the major active site with superior O2 adsorption-desorption mechanisms.In a practical Zn-air battery test,the air electrode coated with Co-N4/NC exhibited a specific capacity(762.8 mAh g(-1))and power density(101.62 mW cm^(-2)),exceeding those of Pt/C-Ru/C(700.8 mAh g^(-1) and 89.16 mW cm^(-2),respectively)at the same catalyst loading.Moreover,for Co-N4/NC,the potential difference increased from 1.16 to 1.47 V after 100 charge-discharge cycles.The proposed innovative and scalable strategy was concluded to be well suited for the fabrication of single-atom-doped carbons as promising bifunctional oxygen evolution/reduction electrocatalysts for metal-air batteries.展开更多
The macrocyclic lactones building on calix[4]arenes 3a-b and double calix[4]arenes 4a-b were synthesized by the reaction of p-tert-butylcalix[4]arene (1a) or calix[4]arene (1b) with glycol bis(2-chloroacetate) (2). Th...The macrocyclic lactones building on calix[4]arenes 3a-b and double calix[4]arenes 4a-b were synthesized by the reaction of p-tert-butylcalix[4]arene (1a) or calix[4]arene (1b) with glycol bis(2-chloroacetate) (2). The conditions to improve the yields of double calix[4]arenes have been discussed.展开更多
New Schiff base Macrocyclic compound of 2,3: 11, 12:20, 21:29, 30-tetrabenzo-1,13,16,19,31,34-hexaoxa-5,6,8,9,23,24,26,27-octaaza-7,25-dithione-2,3:4,5:9,10:11,12:22, 23:27,28:29,30 cyclo-[36]ene (thione2B4[36] ene-O6...New Schiff base Macrocyclic compound of 2,3: 11, 12:20, 21:29, 30-tetrabenzo-1,13,16,19,31,34-hexaoxa-5,6,8,9,23,24,26,27-octaaza-7,25-dithione-2,3:4,5:9,10:11,12:22, 23:27,28:29,30 cyclo-[36]ene (thione2B4[36] ene-O6N8) containing THF has been prepared. It crystallizes in the monoclinic, space group P21/n. with parameters a=9.829(5) b=24.23(1), c=10.181(9), β=92.93(5)°, Z=2, V=2422(3)3, Dc=1.25gcm-3. Data collection: Rigaku AFC-5R diffractometer,(MoKα, λ=0.71069), ω /2θ scans. θmax=25°, empirical absorption correction, 4658 measured reflections, 4387 independent, 1743 observed reflections [I≥3σ(I)]. The final R=0.056. RW=0.069,S=1 .54, (Δ/σ)max=0.01,Δρmax=0.36e-3.展开更多
Two new tetraamides bridged calix[4]arenes were synthesized by the condensation reaction of 1,3-bis-chlorocarbonylmethyl p-tert-butylcalix[4]arene with 1,2-bis (2′-amino-2′-methylpropanamido) benzene or 1,2-bis (2′...Two new tetraamides bridged calix[4]arenes were synthesized by the condensation reaction of 1,3-bis-chlorocarbonylmethyl p-tert-butylcalix[4]arene with 1,2-bis (2′-amino-2′-methylpropanamido) benzene or 1,2-bis (2′-amino-2′-methylpropanamido)-4,5-dichloro benzene, respectively. The new compounds were characterized by1H-NMR, MS-FAB, and elemental analysis; macrocyclic polyamine.展开更多
Two complexes with formulas [Ni L][（Ni L）（IPA）2]·8H2O（1） and [（Ni L）（H2O）2] [（Ni L）（PMA）]·4H2O（2）（L = 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane,IPA2– = isophthalic anion,P...Two complexes with formulas [Ni L][（Ni L）（IPA）2]·8H2O（1） and [（Ni L）（H2O）2] [（Ni L）（PMA）]·4H2O（2）（L = 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane,IPA2– = isophthalic anion,PMA4– = 1,2,4,5-benzenetetracarboxylic anion） were synthesized and characterized by elemental analyses and IR spectra.The crystal structures were determined by X-ray diffraction.In complex 1,the [Ni L]^2＋ bridged IPA^2– to give [（Ni L）（IPA）2]^2– monomer,and the [Ni L]^2＋ bridged PMA4– to form a one-dimensional chain [（Ni L）（PMA）]n^2n– in complex 2.The [Ni L]^2＋ and [（Ni L）（IPA）2]^2–/[（Ni L）（PMA）]^2– are connected through intermolecular hydrogen bonding to generate three-dimensional supramolecular structures.展开更多
Trifluoroacetic acid(TFA)catalyzed condensation reaction between tetraaminooxacalix[4]arene and N-alkylcarbazole-3,6-dicarbaldehyde in CH_(2)Cl2afforded a single product in 87%–89%yield.Well-defined yet undissolvable...Trifluoroacetic acid(TFA)catalyzed condensation reaction between tetraaminooxacalix[4]arene and N-alkylcarbazole-3,6-dicarbaldehyde in CH_(2)Cl2afforded a single product in 87%–89%yield.Well-defined yet undissolvable1H NMR spectra suggested formation of robust and discrete structures in solution.X-ray single crystal analysis further revealed a giant twisted double-layer chiral macrocycle in the solid state,which was formed from[4+8]condensation of the two reactants via 16 imine bonds.DFT calculations discovered that only the[4+8]twisted product is thermodynamically favorable,which accounts for its highly selective and efficient formation out of a library of many other combinations.展开更多
Purpose: The oxidative stress (OS) hypothesis of overtraining syndrome argues that increased production of free radicals through exercise cause muscle fatigue and damage resulting in lower athletic performance. Severa...Purpose: The oxidative stress (OS) hypothesis of overtraining syndrome argues that increased production of free radicals through exercise cause muscle fatigue and damage resulting in lower athletic performance. Several studies have investigated OS immediately before and after exercise bouts in a training macrocycle. Our study aimed to compare OS of endurance athletes between a competition macrocycle and the immediate post-season recovery macrocycle. In addition, we aimed to identify athletes who experienced an unexplainable drop in athletic performance during the competition season in order to compare their OS to those who experienced no drop in performance. Methods: Fifteen members of the University of Alaska Fairbanks cross country ski team volunteered for this study. Blood samples were taken in early February (“mid-season”) and late April (“post-season”). Participants completed questionnaires regarding physical activity and athletic performance at the time of the blood draws. Plasma was analyzed for 4-hydroxynonenal<sup> </sup>(HNE), nitrotyrosine,<sup> </sup>nitric oxide (NOX), and superoxide dismutase (SOD). Significance was determined by Wilcoxon and Mann-Whitney tests. Results: Participants displayed significantly higher (p Conclusion: Signs of oxidative stress and mitigation during the post-season recovery macrocycle were higher in athletes who reported experiencing a drop in athletic performance during the competition season macrocycle.展开更多
基金supported by Global Frontier Program through the Global Frontier Hybrid Interface materials(GFHIM)of the National Research Foundation of Korea(NRF)funded by the ministry of science,ICT and Future Planning(2013M3A6B1078874)co-supported by Busan Innovation Institute of Industry,Science&Technology Planning(BISTEP)+1 种基金the financial support of Federal Ministry of Education and Research(BMBF)under the“Make Our Planet Great Again-German Research Initiative”(MOPGAGRI),57429784implemented by the German Academic Exchange Service Deutscher Akademischer Austauschdienst(DAAD)。
文摘As bifunctional oxygen evolution/reduction electrocatalysts,transition-metal-based single-atom-doped nitrogen-carbon(NC)matrices are promising successors of the corresponding noblemetal-based catalysts,offering the advantages of ultrahigh atom utilization effciency and surface active energy.However,the fabrication of such matrices(e.g.,well-dispersed single-atom-doped M-N4/NCs)often requires numerous steps and tedious processes.Herein,ultrasonic plasma engineering allows direct carbonization in a precursor solution containing metal phthalocyanine and aniline.When combining with the dispersion effect of ultrasonic waves,we successfully fabricated uniform single-atom M-N4(M=Fe,Co)carbon catalysts with a production rate as high as 10 mg min-1.The Co-N4/NC presented a bifunctional potential drop ofΔE=0.79 V,outperforming the benchmark Pt/C-Ru/C catalyst(ΔE=0.88 V)at the same catalyst loading.Theoretical calculations revealed that Co-N4 was the major active site with superior O2 adsorption-desorption mechanisms.In a practical Zn-air battery test,the air electrode coated with Co-N4/NC exhibited a specific capacity(762.8 mAh g(-1))and power density(101.62 mW cm^(-2)),exceeding those of Pt/C-Ru/C(700.8 mAh g^(-1) and 89.16 mW cm^(-2),respectively)at the same catalyst loading.Moreover,for Co-N4/NC,the potential difference increased from 1.16 to 1.47 V after 100 charge-discharge cycles.The proposed innovative and scalable strategy was concluded to be well suited for the fabrication of single-atom-doped carbons as promising bifunctional oxygen evolution/reduction electrocatalysts for metal-air batteries.
文摘The macrocyclic lactones building on calix[4]arenes 3a-b and double calix[4]arenes 4a-b were synthesized by the reaction of p-tert-butylcalix[4]arene (1a) or calix[4]arene (1b) with glycol bis(2-chloroacetate) (2). The conditions to improve the yields of double calix[4]arenes have been discussed.
文摘New Schiff base Macrocyclic compound of 2,3: 11, 12:20, 21:29, 30-tetrabenzo-1,13,16,19,31,34-hexaoxa-5,6,8,9,23,24,26,27-octaaza-7,25-dithione-2,3:4,5:9,10:11,12:22, 23:27,28:29,30 cyclo-[36]ene (thione2B4[36] ene-O6N8) containing THF has been prepared. It crystallizes in the monoclinic, space group P21/n. with parameters a=9.829(5) b=24.23(1), c=10.181(9), β=92.93(5)°, Z=2, V=2422(3)3, Dc=1.25gcm-3. Data collection: Rigaku AFC-5R diffractometer,(MoKα, λ=0.71069), ω /2θ scans. θmax=25°, empirical absorption correction, 4658 measured reflections, 4387 independent, 1743 observed reflections [I≥3σ(I)]. The final R=0.056. RW=0.069,S=1 .54, (Δ/σ)max=0.01,Δρmax=0.36e-3.
文摘Two new tetraamides bridged calix[4]arenes were synthesized by the condensation reaction of 1,3-bis-chlorocarbonylmethyl p-tert-butylcalix[4]arene with 1,2-bis (2′-amino-2′-methylpropanamido) benzene or 1,2-bis (2′-amino-2′-methylpropanamido)-4,5-dichloro benzene, respectively. The new compounds were characterized by1H-NMR, MS-FAB, and elemental analysis; macrocyclic polyamine.
基金supported by the Natural Science Foundation of Hunan Province(2015JJ2072)the Key Laboratory of Comprehensive Utilization of Advantage Plants Resources in Hunan South(XNZW14C08)+1 种基金the Construct Program of the Key Discipline in Hunan Province(2011-76)the Science and Technology Innovative Research Team in Higher Educational Institutions of Hunan Province(2012-318)
文摘Two complexes with formulas [Ni L][（Ni L）（IPA）2]·8H2O（1） and [（Ni L）（H2O）2] [（Ni L）（PMA）]·4H2O（2）（L = 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane,IPA2– = isophthalic anion,PMA4– = 1,2,4,5-benzenetetracarboxylic anion） were synthesized and characterized by elemental analyses and IR spectra.The crystal structures were determined by X-ray diffraction.In complex 1,the [Ni L]^2＋ bridged IPA^2– to give [（Ni L）（IPA）2]^2– monomer,and the [Ni L]^2＋ bridged PMA4– to form a one-dimensional chain [（Ni L）（PMA）]n^2n– in complex 2.The [Ni L]^2＋ and [（Ni L）（IPA）2]^2–/[（Ni L）（PMA）]^2– are connected through intermolecular hydrogen bonding to generate three-dimensional supramolecular structures.
基金supported by the National Natural Science Foundation of China(Nos.21971223 and 21772178)。
文摘Trifluoroacetic acid(TFA)catalyzed condensation reaction between tetraaminooxacalix[4]arene and N-alkylcarbazole-3,6-dicarbaldehyde in CH_(2)Cl2afforded a single product in 87%–89%yield.Well-defined yet undissolvable1H NMR spectra suggested formation of robust and discrete structures in solution.X-ray single crystal analysis further revealed a giant twisted double-layer chiral macrocycle in the solid state,which was formed from[4+8]condensation of the two reactants via 16 imine bonds.DFT calculations discovered that only the[4+8]twisted product is thermodynamically favorable,which accounts for its highly selective and efficient formation out of a library of many other combinations.
文摘Purpose: The oxidative stress (OS) hypothesis of overtraining syndrome argues that increased production of free radicals through exercise cause muscle fatigue and damage resulting in lower athletic performance. Several studies have investigated OS immediately before and after exercise bouts in a training macrocycle. Our study aimed to compare OS of endurance athletes between a competition macrocycle and the immediate post-season recovery macrocycle. In addition, we aimed to identify athletes who experienced an unexplainable drop in athletic performance during the competition season in order to compare their OS to those who experienced no drop in performance. Methods: Fifteen members of the University of Alaska Fairbanks cross country ski team volunteered for this study. Blood samples were taken in early February (“mid-season”) and late April (“post-season”). Participants completed questionnaires regarding physical activity and athletic performance at the time of the blood draws. Plasma was analyzed for 4-hydroxynonenal<sup> </sup>(HNE), nitrotyrosine,<sup> </sup>nitric oxide (NOX), and superoxide dismutase (SOD). Significance was determined by Wilcoxon and Mann-Whitney tests. Results: Participants displayed significantly higher (p Conclusion: Signs of oxidative stress and mitigation during the post-season recovery macrocycle were higher in athletes who reported experiencing a drop in athletic performance during the competition season macrocycle.
