Under the optimum experimental conditions (i. e., pH=1.6, c KI=10.6 mmol/L, =5.4 mmol/L, =1.30 mmol/L) derived from simplex operations, trace molybdenum(VI) was determined through the agency of its catalytic effect ...Under the optimum experimental conditions (i. e., pH=1.6, c KI=10.6 mmol/L, =5.4 mmol/L, =1.30 mmol/L) derived from simplex operations, trace molybdenum(VI) was determined through the agency of its catalytic effect on the reaction of H2O2 with I? in acid medium. The detection limit and linear calibration range of molybdenum were obtained as 0.5×10?6 mol/L and 0.5×10?6～120×10?6mol/L respectively. This method was applied to the examination of the industrial waste water, and the recovery ratios were found to be in the range of 101% and 107%. Key words oscillographic potentiometry - catalyzing kinetic analysis - simplex optimization - molybdenum Supported by the National Natural Science Foundation of China (Grant No. 20175013) and the Higher Education Development Foundation of Shanghai in China (Grant No. 01A17)展开更多
The mechanism of additive ZC 1 for catalyzing combustion of coke breeze in sintering of iron ore fines was studied by using X ray Diffraction, TGA and GC(Gas Chromatographer), by which energy saving was achieved on si...The mechanism of additive ZC 1 for catalyzing combustion of coke breeze in sintering of iron ore fines was studied by using X ray Diffraction, TGA and GC(Gas Chromatographer), by which energy saving was achieved on sinter pot test. The results show that the distance between cleavage planes is enlarged and the π electrons are re distributed because of the insertion of cations/molecules of ZC 1 into the cleavage planes of carbon , resulting in the weakening of C-C bond, improving the adsorption of oxygen and lowering the activation energy of gasification of carbon from 25.8 kJ/mol to 18.9 kJ/mol , and the burning rate being increased and combustion residual reduced, all of which can lead to lower solid fuel consumption . Compared with the sintering test without addition of additives , the solid fuel consumption is reduced by 16.0%, meanwhile, the rate of finished sinter, the output of finished sinter and the tumbling index are increased by 2.03%, 7.0% and 3.71% , respectively, with incorporating 0.2% of additive ZC 1 in the sintering mixture, which is in agreement with the catalyzing mechanism of ZC 1.展开更多
Nymphaea is a key genus of the ANA grade(Amborellales,Nymphaeales,and Austrobaileyales)of basal flowering plants,which serve as a key model to study the early evolution of floral traits.In this study,we comprehensivel...Nymphaea is a key genus of the ANA grade(Amborellales,Nymphaeales,and Austrobaileyales)of basal flowering plants,which serve as a key model to study the early evolution of floral traits.In this study,we comprehensively investigated the emission,biosynthesis,and biological function of the floral scent in a night-blossoming waterlily Nymphaea prolifera.The headspace volatile collection combined with GC-MS analysis showed that the floral scent of N.prolifera is predominately comprised by methylated benzenoids including anisole,veratrole,guaiacol,and methoxyanisole.Moreover,the emission of these floral benzenoids in N.prolifera exhibited temporal and spatial pattern with circadian rhythm and tissue specificity.By creating and mining transcriptomes of N.prolifera flowers,12 oxygen methyltransferases(NpOMTs)were functionally identified.By in vitro enzymatic assay,NpOMT3,6,and 7 could produce anisole and NpOMT5,7,9,produce guaiacol,whereas NpOMT3,6,9,11 catalyzed the formation of veratrole.Methoxyanisole was identified as the universal product of all NpOMTs.Expression patterns of NpOMTs provided implication for their roles in the production of the respective benzenoids.Phylogenetic analysis of OMTs suggested a Nymphaea-specific expansion of the OMT family,indicating the evolution of lineage-specific functions.In bioassays,anisole,veratrole,and guaiacol in the floral benzenoids were revealed to play the critical role in repelling waterlily aphids.Overall,this study indicates that the basal flowering plant N.prolifera has evolved a diversity and complexity of OMT genes for the biosynthesis of methylated benzenoids that can repel insects from feeding the flowers.These findings provide new insights into the evolutional mechanism and ecological significance of the floral scent from early-diverged flowering plants.展开更多
Amyloid-β 1-42(Aβ42)plays a pivotal role in Alzheimer disease(AD)pathogenesis. Peripheral clearance of Aβ42 largely affects its level in the brain and affects AD progression. Although nattokinase(NK)degrades Aβ40,...Amyloid-β 1-42(Aβ42)plays a pivotal role in Alzheimer disease(AD)pathogenesis. Peripheral clearance of Aβ42 largely affects its level in the brain and affects AD progression. Although nattokinase(NK)degrades Aβ40, the details of NK's capture of various Aβ species and reduction of plasma Aβ42/Aβ40 are uncharacterized. In this study, the Aβ42/Aβ40-degrading ability of NK was investigated using five Aβs and AD model mice. The C-terminal region of Aβ42/Aβ40(Gly29 to Val40)was primarily required for NK capture, and the integrated conformation in Aβ42/Aβ40 aggregates was a more efficient target for NK catalysis. Further, suspended Aβ42/Aβ40 oligomers were more easily captured by NK than suspended Aβ42/Aβ40 fibrils, while deposited Aβ42/Aβ40 fibrils recruited more NK than deposited Aβ42/Aβ40 oligomers. Although most NK was likely lost during NK uptake and/or entry into the blood, a small fraction of NK showed good plasma Aβ42/Aβ40-degrading efficacy after entering the blood due to NK's stability in the plasma of AD mice for at least 9 days. It was concluded that oral administration of NK is a feasible approach for peripheral Aβ42/Aβ40 clearance. This implies that NK might serve as an anti-Aβ42 agent for the treatment of Aβ42/Aβ40-related diseases such as AD.展开更多
To overcome the limitation in formability at room temperature,manufacturers have developed magnesium alloys with remarkable properties by adding rare-earth elements.The rare-earth magnesium alloys behave differently f...To overcome the limitation in formability at room temperature,manufacturers have developed magnesium alloys with remarkable properties by adding rare-earth elements.The rare-earth magnesium alloys behave differently from the conventional alloys,especially with respect to their coupled anisotropic and strain rate sensitive behavior.In the current work,such behavior of the rare-earth Mg alloy ZEK100 sheet at room temperature is investigated with the aid of the elastic viscoplastic self-consistent polycrystal plasticity model.Different strain rate sensitivities(SRSs)for various deformation modes are employed by the model to simulate the strain rate sensitive behaviors under different loading directions and loading rates.Good agreement between the experiments and simulations reveals the importance and necessity of using different SRSs for each deformation mode in hexagonal close-packed metals.Furthermore,the relative activities of each deformation mode and the texture evolution during different loadings are discussed.The anisotropic and strain rate sensitive behavior is ascribed to the various operating deformation modes with different SRSs during loading along different directions.展开更多
A new and simple route for the synthesis of α,β-unsaturated ketones via cleavage of the C-C(O)C single bond of monoalkylated β-diketone has been described. The reaction was catalyzed by copper, a cheap transition m...A new and simple route for the synthesis of α,β-unsaturated ketones via cleavage of the C-C(O)C single bond of monoalkylated β-diketone has been described. The reaction was catalyzed by copper, a cheap transition metal in a weakly basic medium (K<sub>3</sub>PO<sub>4</sub>) at room temperature. To carry out this study, we first had to synthesize the monoalkylated β-diketones 1. Afterwards, α,β-unsaturated ketones 2 were obtained with high yields around 80%. Finally, all the products were characterized by 1H NMR, 13C NMR, and HRMS spectra. .展开更多
文摘Under the optimum experimental conditions (i. e., pH=1.6, c KI=10.6 mmol/L, =5.4 mmol/L, =1.30 mmol/L) derived from simplex operations, trace molybdenum(VI) was determined through the agency of its catalytic effect on the reaction of H2O2 with I? in acid medium. The detection limit and linear calibration range of molybdenum were obtained as 0.5×10?6 mol/L and 0.5×10?6～120×10?6mol/L respectively. This method was applied to the examination of the industrial waste water, and the recovery ratios were found to be in the range of 101% and 107%. Key words oscillographic potentiometry - catalyzing kinetic analysis - simplex optimization - molybdenum Supported by the National Natural Science Foundation of China (Grant No. 20175013) and the Higher Education Development Foundation of Shanghai in China (Grant No. 01A17)
基金TheFoundationfortheTeachingandResearchProgramforOutstandingYoungTeachersinHigherEducationInstitu tionsofMOE P .R .C .
文摘The mechanism of additive ZC 1 for catalyzing combustion of coke breeze in sintering of iron ore fines was studied by using X ray Diffraction, TGA and GC(Gas Chromatographer), by which energy saving was achieved on sinter pot test. The results show that the distance between cleavage planes is enlarged and the π electrons are re distributed because of the insertion of cations/molecules of ZC 1 into the cleavage planes of carbon , resulting in the weakening of C-C bond, improving the adsorption of oxygen and lowering the activation energy of gasification of carbon from 25.8 kJ/mol to 18.9 kJ/mol , and the burning rate being increased and combustion residual reduced, all of which can lead to lower solid fuel consumption . Compared with the sintering test without addition of additives , the solid fuel consumption is reduced by 16.0%, meanwhile, the rate of finished sinter, the output of finished sinter and the tumbling index are increased by 2.03%, 7.0% and 3.71% , respectively, with incorporating 0.2% of additive ZC 1 in the sintering mixture, which is in agreement with the catalyzing mechanism of ZC 1.
基金This work was supported by the National Natural Science Foundation of China(31872140,31470693,31100503)the Natural Science Foundation of Zhejiang Province(LY18C160006)+1 种基金the Zhejiang Provincial Key Laboratory of Characteristic Aquatic Vegetable Breeding and Cultivation Open Fund Project(KL-2022-01,KL-2022-02)the Project for Science and Technology in Jinhua City(Grant No.2019-2-002).The authors thank TopEdit(www.topeditsci.com)for its linguistic assistance during the preparation of this manuscript.
文摘Nymphaea is a key genus of the ANA grade(Amborellales,Nymphaeales,and Austrobaileyales)of basal flowering plants,which serve as a key model to study the early evolution of floral traits.In this study,we comprehensively investigated the emission,biosynthesis,and biological function of the floral scent in a night-blossoming waterlily Nymphaea prolifera.The headspace volatile collection combined with GC-MS analysis showed that the floral scent of N.prolifera is predominately comprised by methylated benzenoids including anisole,veratrole,guaiacol,and methoxyanisole.Moreover,the emission of these floral benzenoids in N.prolifera exhibited temporal and spatial pattern with circadian rhythm and tissue specificity.By creating and mining transcriptomes of N.prolifera flowers,12 oxygen methyltransferases(NpOMTs)were functionally identified.By in vitro enzymatic assay,NpOMT3,6,and 7 could produce anisole and NpOMT5,7,9,produce guaiacol,whereas NpOMT3,6,9,11 catalyzed the formation of veratrole.Methoxyanisole was identified as the universal product of all NpOMTs.Expression patterns of NpOMTs provided implication for their roles in the production of the respective benzenoids.Phylogenetic analysis of OMTs suggested a Nymphaea-specific expansion of the OMT family,indicating the evolution of lineage-specific functions.In bioassays,anisole,veratrole,and guaiacol in the floral benzenoids were revealed to play the critical role in repelling waterlily aphids.Overall,this study indicates that the basal flowering plant N.prolifera has evolved a diversity and complexity of OMT genes for the biosynthesis of methylated benzenoids that can repel insects from feeding the flowers.These findings provide new insights into the evolutional mechanism and ecological significance of the floral scent from early-diverged flowering plants.
基金supported by the National Natural Science Foundation of China Program (No. 31970883)。
文摘Amyloid-β 1-42(Aβ42)plays a pivotal role in Alzheimer disease(AD)pathogenesis. Peripheral clearance of Aβ42 largely affects its level in the brain and affects AD progression. Although nattokinase(NK)degrades Aβ40, the details of NK's capture of various Aβ species and reduction of plasma Aβ42/Aβ40 are uncharacterized. In this study, the Aβ42/Aβ40-degrading ability of NK was investigated using five Aβs and AD model mice. The C-terminal region of Aβ42/Aβ40(Gly29 to Val40)was primarily required for NK capture, and the integrated conformation in Aβ42/Aβ40 aggregates was a more efficient target for NK catalysis. Further, suspended Aβ42/Aβ40 oligomers were more easily captured by NK than suspended Aβ42/Aβ40 fibrils, while deposited Aβ42/Aβ40 fibrils recruited more NK than deposited Aβ42/Aβ40 oligomers. Although most NK was likely lost during NK uptake and/or entry into the blood, a small fraction of NK showed good plasma Aβ42/Aβ40-degrading efficacy after entering the blood due to NK's stability in the plasma of AD mice for at least 9 days. It was concluded that oral administration of NK is a feasible approach for peripheral Aβ42/Aβ40 clearance. This implies that NK might serve as an anti-Aβ42 agent for the treatment of Aβ42/Aβ40-related diseases such as AD.
基金supported by the National Natural Science Foundation of China(No.51975365)the Shanghai Pujiang Program(18PJ1405000)+1 种基金supported by the Natural Sciences and Engineering Research Council of Canada(NSERC)the Province of Ontario
文摘To overcome the limitation in formability at room temperature,manufacturers have developed magnesium alloys with remarkable properties by adding rare-earth elements.The rare-earth magnesium alloys behave differently from the conventional alloys,especially with respect to their coupled anisotropic and strain rate sensitive behavior.In the current work,such behavior of the rare-earth Mg alloy ZEK100 sheet at room temperature is investigated with the aid of the elastic viscoplastic self-consistent polycrystal plasticity model.Different strain rate sensitivities(SRSs)for various deformation modes are employed by the model to simulate the strain rate sensitive behaviors under different loading directions and loading rates.Good agreement between the experiments and simulations reveals the importance and necessity of using different SRSs for each deformation mode in hexagonal close-packed metals.Furthermore,the relative activities of each deformation mode and the texture evolution during different loadings are discussed.The anisotropic and strain rate sensitive behavior is ascribed to the various operating deformation modes with different SRSs during loading along different directions.
文摘A new and simple route for the synthesis of α,β-unsaturated ketones via cleavage of the C-C(O)C single bond of monoalkylated β-diketone has been described. The reaction was catalyzed by copper, a cheap transition metal in a weakly basic medium (K<sub>3</sub>PO<sub>4</sub>) at room temperature. To carry out this study, we first had to synthesize the monoalkylated β-diketones 1. Afterwards, α,β-unsaturated ketones 2 were obtained with high yields around 80%. Finally, all the products were characterized by 1H NMR, 13C NMR, and HRMS spectra. .
