Alkali-activated cement(AAC)is either clinker-less or free,and it is also environmentally friendly due to its low carbon footprint and wide range sources.Industrial wastes,like steel slag and blastfurnace slag,usually...Alkali-activated cement(AAC)is either clinker-less or free,and it is also environmentally friendly due to its low carbon footprint and wide range sources.Industrial wastes,like steel slag and blastfurnace slag,usually have latent hydraulic reactivity,and can be used as precursors of AAC.Both clinkerless and clinker-free AAC were prepared from the mixture of steel slag and blastfurnace slag by using water glass as an activator,and four different recipes which satisfied the strength requirement of 42.5R Portland cement were obtained.Each recipe of AAC exhibited better resistance to sulfate attack and frost attack than Portland cement.AAC showed huge drying shrinkage,but it was equivalent to that of Portland cement as steel slag content increased to 40%.The AAC also had quite low risk of alkali-aggregate reaction.Microstructure analysis showed that the major products were calcium silicate hydrate(C–S–H),calcium aluminosilicate hydrate(C–A–S–H)and zeolite-like phases.Ettringite was also detected in the binder when gypsum was contained in the precursors.展开更多
We investigate an optimal harvesting problem for age-structured species,in which elder individuals are more competitive than younger ones,and the population is modeled by a highly nonlinear integro-partial differentia...We investigate an optimal harvesting problem for age-structured species,in which elder individuals are more competitive than younger ones,and the population is modeled by a highly nonlinear integro-partial differential equation with a global feedback boundary condition.The existence of optimal strategies is established by means of compactness and maximizing sequences,and the maximum principle obtained via an adjoint system,tangent-normal cones and a new continuity result.In addition,some numerical experiments are presented to show the effects of the price function and younger's weight on the optimal profits.展开更多
This paper is concerned with the global dynamics of a hierarchical population model,in which the fertility of an individual depends on the total number of higher-ranking members.We investigate the stability of equilib...This paper is concerned with the global dynamics of a hierarchical population model,in which the fertility of an individual depends on the total number of higher-ranking members.We investigate the stability of equilibria,nonexistence of periodic orbits and the persistence of the population by means of eigenvalues,Lyapunov function,and several results in discrete dynamical systems.Our work demonstrates that the reproductive number governs the evolution of the population.Besides the theoretical results,some numerical experiments are also presented.展开更多
Objective To develop a sensitive and rapid liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) method for the simultaneous determination of wogonin, coptisine, berberine, palmatine,...Objective To develop a sensitive and rapid liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) method for the simultaneous determination of wogonin, coptisine, berberine, palmatine, jatrorrhizine, phellodendrine, magnoflorine, and wogonoside in rat plasma and to evaluate the pharmacokinetic characteristics of Huanglian Jiedu Decoction (HJD). Methods LC separation was performed on an Acquity HSS T3 column (100 mm × 2.1 mm, 1.8 μm) using gradient elution with the mobile phase consisting of acetonitrile and 0.1% formic acid water. The detection was accomplished by using positive electrospray ionization in multiple-reaction monitoring mode. Plasma samples were pretreated by protein precipitation. Results The method showed a good linearity over a wide concentration range (r^2 〉 0.99). The lower limits of quantification were 0.20 ng/mL for coptisine and phellodendrine, 0.48 ng/mL for berberine, 0.10 ng/mL for jatrorrhizine, 0.32 ng/mL for magnoflorine, 0.30 ng/mL for palmatine, and 4.80 ng/mL for wogonin and wogonoside, respectively. The intra- and inter-day precision of the analytes was less than 12.11%, while the accuracy was between -14.46% and 4.86%. The mean recovery of all the analytes ranged from 93.10% to 110.91%. Conclusion This validated method offers thee advantages of high sensitivity. It is successfully applied to evaluating the pharmacokinetic properties of HJD.展开更多
Three tetraurea-appended porphyrin derivatives were synthesized and applied as anion receptors to complex with various anions, including F^-, Cl^-, Br^-, I^-, NO3^-, HSO4^-, and AcO^-. The binding stoichiometries were...Three tetraurea-appended porphyrin derivatives were synthesized and applied as anion receptors to complex with various anions, including F^-, Cl^-, Br^-, I^-, NO3^-, HSO4^-, and AcO^-. The binding stoichiometries were all measured to be 1:1 and high binding abilities of these receptors toward the anions were demonstrated with the association constants of up to 1.1 × 10^8 L/mol. The complexation of the receptors with anions was further unambiguously confirmed by single-crystal X-ray analysis展开更多
A series of lanthanide complexes [Ln(4-Cl-2-MOBA)3phen]2(Ln=Sm(1), Nd(2), Ho(3), Eu(4), Dy(5), and Tb(6); 4-Cl-2-MOBA=4-chloro-2-methoxybenzoate, phen=1,10-phenanthroline) were synthesized and characterized. The singl...A series of lanthanide complexes [Ln(4-Cl-2-MOBA)3phen]2(Ln=Sm(1), Nd(2), Ho(3), Eu(4), Dy(5), and Tb(6); 4-Cl-2-MOBA=4-chloro-2-methoxybenzoate, phen=1,10-phenanthroline) were synthesized and characterized. The single-crystal X-ray diffraction demonstrates that 1–3 are isomorphous, which present dimeric structures with four 4-Cl-2-MOBA anions function as bridging ligands. Complexes 1 and 4–6 display their characteristic luminescence emission bands of central Ln3?ions. The heat capacities, the thermodynamic functions and the thermogravimetry–Fourier transform infrared spectra of gaseous products of complexes 1–6 were investigated.Their non-isothermal kinetics of the second decomposition stage was studied by the integral isoconversional non-linear method and Stark method. Furthermore, 1–6 exhibited excellent antibacterial activity against Candida albicans,Escherichia coli and Staphylococcus aureu.展开更多
The medicinal part of Aucklandia lappa(Asteraceae) is its dried root,which is one of the commonly used Chinese medicinal materials.Here we reviewed sesquiterpene lactones isolated from A.lappa over the past ten years ...The medicinal part of Aucklandia lappa(Asteraceae) is its dried root,which is one of the commonly used Chinese medicinal materials.Here we reviewed sesquiterpene lactones isolated from A.lappa over the past ten years in the following aspects of pharmacological activities,pharmacokinetics,toxicology,structure-activity relationship.Pharmacological activities consist of anti-cancer,anti-inflammatory activity,anti-immunity activity,anti-oxidant activity,antimicrobial activity,spasmolytic activity and so on.The extractive,showing similar pharmacokinetics parameters,may exert their various biological activities by the interaction of their α-methylene-γ-butyrolactone moiety with the thiol groups of biomacromolecules through Michael-addition.However,the poor aqueous solubility,non-selective binding as a Michael acceptor at undesired targets limited clinical translation of this class.In order to evaluate the potential effect of the extractive applied in clinical trial,the present review outlines information on pharmacological activities,pharmacokinetics,toxicology,and structure-activity relationship,as well as the future research directions of the extractive for further development and utilization of A.lappa.展开更多
基金supported by the Natural Science Foundation Project of Chongqing(cstc2020jcyj-msxmX0954)the Chongqing Outstanding Youth Project(cstc2019JCYJQX0024)the National Natural Science Foundation of China(52204415.U1902217)。
文摘Alkali-activated cement(AAC)is either clinker-less or free,and it is also environmentally friendly due to its low carbon footprint and wide range sources.Industrial wastes,like steel slag and blastfurnace slag,usually have latent hydraulic reactivity,and can be used as precursors of AAC.Both clinkerless and clinker-free AAC were prepared from the mixture of steel slag and blastfurnace slag by using water glass as an activator,and four different recipes which satisfied the strength requirement of 42.5R Portland cement were obtained.Each recipe of AAC exhibited better resistance to sulfate attack and frost attack than Portland cement.AAC showed huge drying shrinkage,but it was equivalent to that of Portland cement as steel slag content increased to 40%.The AAC also had quite low risk of alkali-aggregate reaction.Microstructure analysis showed that the major products were calcium silicate hydrate(C–S–H),calcium aluminosilicate hydrate(C–A–S–H)and zeolite-like phases.Ettringite was also detected in the binder when gypsum was contained in the precursors.
基金the National Natural Science Foundation of China(11871185)Zhejiang Provincial Natural Science Foundation of China(LY18A010010).
文摘We investigate an optimal harvesting problem for age-structured species,in which elder individuals are more competitive than younger ones,and the population is modeled by a highly nonlinear integro-partial differential equation with a global feedback boundary condition.The existence of optimal strategies is established by means of compactness and maximizing sequences,and the maximum principle obtained via an adjoint system,tangent-normal cones and a new continuity result.In addition,some numerical experiments are presented to show the effects of the price function and younger's weight on the optimal profits.
基金National Natural Science Foundation of China(No.11871185)Zhejiang Provincial Natural Science Foundation of China(LY18A010010).
文摘This paper is concerned with the global dynamics of a hierarchical population model,in which the fertility of an individual depends on the total number of higher-ranking members.We investigate the stability of equilibria,nonexistence of periodic orbits and the persistence of the population by means of eigenvalues,Lyapunov function,and several results in discrete dynamical systems.Our work demonstrates that the reproductive number governs the evolution of the population.Besides the theoretical results,some numerical experiments are also presented.
基金Program NCET Foundation NSFC(81230090)Global Research Network for Medicinal Plants and King Saud University,Shanghai Leading Academic Discipline Project(B906)+3 种基金Key laboratory of drug research for special environments,PLA,Shanghai Engineering Research Center for the Preparation of Bioactive Natural Products(10DZ2251300)Scientific Foundation of Shanghai China(12401900801,09DZ1975700,09DZ1971500,10DZ1971700)National Major Project of China(2011ZX09307-002-03)National Key Technology R&D Program of China(2012BAI29B06)
文摘Objective To develop a sensitive and rapid liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) method for the simultaneous determination of wogonin, coptisine, berberine, palmatine, jatrorrhizine, phellodendrine, magnoflorine, and wogonoside in rat plasma and to evaluate the pharmacokinetic characteristics of Huanglian Jiedu Decoction (HJD). Methods LC separation was performed on an Acquity HSS T3 column (100 mm × 2.1 mm, 1.8 μm) using gradient elution with the mobile phase consisting of acetonitrile and 0.1% formic acid water. The detection was accomplished by using positive electrospray ionization in multiple-reaction monitoring mode. Plasma samples were pretreated by protein precipitation. Results The method showed a good linearity over a wide concentration range (r^2 〉 0.99). The lower limits of quantification were 0.20 ng/mL for coptisine and phellodendrine, 0.48 ng/mL for berberine, 0.10 ng/mL for jatrorrhizine, 0.32 ng/mL for magnoflorine, 0.30 ng/mL for palmatine, and 4.80 ng/mL for wogonin and wogonoside, respectively. The intra- and inter-day precision of the analytes was less than 12.11%, while the accuracy was between -14.46% and 4.86%. The mean recovery of all the analytes ranged from 93.10% to 110.91%. Conclusion This validated method offers thee advantages of high sensitivity. It is successfully applied to evaluating the pharmacokinetic properties of HJD.
基金supported by the National Natural Science Foundation of China(Nos.21572042 and 21773052)the Program for Innovative Research Team in Chinese University(No.IRT 1231)+1 种基金the Natural Science Foundation of Zhejing Province(Nos.LZ16B020002 and LQ17B040002)the Public Welfare Technology and Application Program of Zhejiang Province(No.2015C31141)
文摘Three tetraurea-appended porphyrin derivatives were synthesized and applied as anion receptors to complex with various anions, including F^-, Cl^-, Br^-, I^-, NO3^-, HSO4^-, and AcO^-. The binding stoichiometries were all measured to be 1:1 and high binding abilities of these receptors toward the anions were demonstrated with the association constants of up to 1.1 × 10^8 L/mol. The complexation of the receptors with anions was further unambiguously confirmed by single-crystal X-ray analysis
基金supported by the National Natural Science Foundation of China (21073053, 21173067 and 20773034)the Natural Science Foundation of Hebei Province (B2012205022, B2011205037)
文摘A series of lanthanide complexes [Ln(4-Cl-2-MOBA)3phen]2(Ln=Sm(1), Nd(2), Ho(3), Eu(4), Dy(5), and Tb(6); 4-Cl-2-MOBA=4-chloro-2-methoxybenzoate, phen=1,10-phenanthroline) were synthesized and characterized. The single-crystal X-ray diffraction demonstrates that 1–3 are isomorphous, which present dimeric structures with four 4-Cl-2-MOBA anions function as bridging ligands. Complexes 1 and 4–6 display their characteristic luminescence emission bands of central Ln3?ions. The heat capacities, the thermodynamic functions and the thermogravimetry–Fourier transform infrared spectra of gaseous products of complexes 1–6 were investigated.Their non-isothermal kinetics of the second decomposition stage was studied by the integral isoconversional non-linear method and Stark method. Furthermore, 1–6 exhibited excellent antibacterial activity against Candida albicans,Escherichia coli and Staphylococcus aureu.
基金supported by Special Financial Grant from the China Postdoctoral Science Foundation (No.2015T81140)National Natural Science Foundation of China Youth Fund Project (No.81503467)。
文摘The medicinal part of Aucklandia lappa(Asteraceae) is its dried root,which is one of the commonly used Chinese medicinal materials.Here we reviewed sesquiterpene lactones isolated from A.lappa over the past ten years in the following aspects of pharmacological activities,pharmacokinetics,toxicology,structure-activity relationship.Pharmacological activities consist of anti-cancer,anti-inflammatory activity,anti-immunity activity,anti-oxidant activity,antimicrobial activity,spasmolytic activity and so on.The extractive,showing similar pharmacokinetics parameters,may exert their various biological activities by the interaction of their α-methylene-γ-butyrolactone moiety with the thiol groups of biomacromolecules through Michael-addition.However,the poor aqueous solubility,non-selective binding as a Michael acceptor at undesired targets limited clinical translation of this class.In order to evaluate the potential effect of the extractive applied in clinical trial,the present review outlines information on pharmacological activities,pharmacokinetics,toxicology,and structure-activity relationship,as well as the future research directions of the extractive for further development and utilization of A.lappa.