Some basic concepts about the active structures were firstly explained, and the main subjects to study in the field of active structure dynamics were synthesized. For the linear active structures, the annotations on t...Some basic concepts about the active structures were firstly explained, and the main subjects to study in the field of active structure dynamics were synthesized. For the linear active structures, the annotations on the modes were done in detail. The physical meanings of the right and left eigenvectors were explained. The right eigenvectors are the modal shapes and the modal responses of an active structure depend on the left ones. The adjoint structure of an active structure was defined and the reciprocity theorem was interpreted. For two active structures, which are adjoint to each other and with the reciprocal gain-matrices, the right and left eigenvector are reciprocal. The relationship between an active structure and the corresponding passive structure is expressed with the transfer functions, which is employed to resolve the estimation problems.展开更多
The basic concepts about the active structures and some attributes of the modes were presented in paper “Liner Active Structures and Modes]( I) ". The characteristics of the active discrete systems and active be...The basic concepts about the active structures and some attributes of the modes were presented in paper “Liner Active Structures and Modes]( I) ". The characteristics of the active discrete systems and active beams were discussed, especially, the stability of the active structures and the orthogonality of the eigenvectors. The notes about modes were portrayed by a model of a seven-storeyed building with sensors and actuators. The concept of the adjoint active structure was extended from the discrete systems to the beams that were the representations of the continuous structures. Two types of beams with different placements of the measuring and actuating systems were discussed in detail. One is the beam with the discrete sensors and actuators, and the other is the beam with distributed sensor and actuator function. The orthogonality conditions were derived with the modal shapes of the active beam and its adjoint active beam. An example shows that the variation of eigenvalues with feedback amplitude for the homo-configuration and non-homo-configuration active structures.展开更多
Peptides are functional active fragments of proteins which can provide nutrients needed for human growth and development,and they also have unique physiological activity characteristics relative to proteins.Bioactive ...Peptides are functional active fragments of proteins which can provide nutrients needed for human growth and development,and they also have unique physiological activity characteristics relative to proteins.Bioactive peptides contain a great deal of development potential.More specifically,food-derived bioactive peptides have the advantages of a wide variety of sources,unique structures,high efficiency and safety,so they have broad development prospects.This review provides an overview of the current advances regarding the preparation,functional characteristics,and structure–activity relationships of food-derived bioactive peptides.Moreover,the prospects for the future development and application of food-derived bioactive peptides are discussed.This review may provide a better understanding of foodderived bioactive peptides,and some constructive inspirations for further research and applications in the food industry.展开更多
The polynomial matrix using the block coefficient matrix representation auto-regressive moving average(referred to as the PM-ARMA)model is constructed in this paper for actively controlled multi-degree-of-freedom(MDOF...The polynomial matrix using the block coefficient matrix representation auto-regressive moving average(referred to as the PM-ARMA)model is constructed in this paper for actively controlled multi-degree-of-freedom(MDOF)structures with time-delay through equivalently transforming the preliminary state space realization into the new state space realization.The PM-ARMA model is a more general formulation with respect to the polynomial using the coefficient representation auto-regressive moving average(ARMA)model due to its capability to cope with actively controlled structures with any given structural degrees of freedom and any chosen number of sensors and actuators.(The sensors and actuators are required to maintain the identical number.)under any dimensional stationary stochastic excitation.展开更多
Precisely tuning the spacing of the active centers on the atomic scale is of great significance to improve the catalytic activity and deepen the understanding of the catalytic mechanism,but still remains a challenge.H...Precisely tuning the spacing of the active centers on the atomic scale is of great significance to improve the catalytic activity and deepen the understanding of the catalytic mechanism,but still remains a challenge.Here,we develop a strategy to dilute catalytically active metal interatomic spacing(d_(M-M))with light atoms and discover the unusual adsorption patterns.For example,by elevating the content of boron as interstitial atoms,the atomic spacing of osmium(d_(Os-Os))gradually increases from 2.73 to 2.96?.More importantly,we find that,with the increase in dOs-Os,the hydrogen adsorption-distance relationship is reversed via downshifting d-band states,which breaks the traditional cognition,thereby optimizing the H adsorption and H_2O dissociation on the electrode surface during the catalytic process;this finally leads to a nearly linear increase in hydrogen evolution reaction activity.Namely,the maximum dOs-Os of 2.96?presents the optimal HER activity(8 mV@10 mA cm^(-2))in alkaline media as well as suppressed O adsorption and thus promoted stability.It is believed that this novel atomic-level distance modulation strategy of catalytic sites and the reversed hydrogen adsorption-distance relationship can shew new insights for optimal design of highly efficient catalysts.展开更多
In this paper,the functional polymeric active materials were prepared by the grafting copolymerization and their structure and properties were studied.The results show that the structure and properties of these ac- ti...In this paper,the functional polymeric active materials were prepared by the grafting copolymerization and their structure and properties were studied.The results show that the structure and properties of these ac- tive materials have the relative large effects on the properties of gadolinium ion selective electrodes.展开更多
To utilize themultiple functions and give full play of ginsenosides,a variety of ginsenosides with different structures were prepared into liposomes and evaluated for their effect on the stability,pharmacokinetics and...To utilize themultiple functions and give full play of ginsenosides,a variety of ginsenosides with different structures were prepared into liposomes and evaluated for their effect on the stability,pharmacokinetics and tumor targeting capability of liposomes.The results showed that the position and number of glycosyl groups of ginsenosides have significant effect on the in vitro and in vivo properties of their liposomes.The pharmacokinetics of ginsenosides liposomes indicated that the C-3 sugar group of ginsenosides is beneficial to their liposomes for longer circulation in vivo.The C-3 and C-6 glycosyls can enhance the uptake of their liposomes by 4T1 cells,and the glycosyls at C-3 position can enhance the tumor active targeting ability significantly,based on the specific binding capacity to Glut 1 expressed on the surface of 4T1 cells.According to the results in the study,ginsenoside Rg3 and ginsenoside Rh2 are potential for exploiting novel liposomes because of their cholesterol substitution,long blood circulation and tumor targeting capabilities.The results provide a theoretical basis for further development of ginsenoside based liposome delivery systems.展开更多
A layered crustal block model of North China has been constructed based on large amount of data from seismic sounding carried out in recent two decades. Some deep fault zones, such as the Zhangjiakou.Penglai and Tanch...A layered crustal block model of North China has been constructed based on large amount of data from seismic sounding carried out in recent two decades. Some deep fault zones, such as the Zhangjiakou.Penglai and Tancheng-Lujiang fault zones, divide the upper crust of North China into three upper crustal terranes and nine bolcks. There are distinct differences in velocity and depth distributions, which reflects Cenozoic block faulting in North China in the process of formation of the deep structure. The upper crust shows the features of transition in isostatic adjustment. The existence of a low-velocity layer in the middle crust is characteristic of the crustal structure in North China. There seems to be an increase of rheology of the rocks in the lower crust and a persistence of stable regional stress field. The patterns of the Moho on two sides of the Yanshan-Taihang Mountains are different. The relief of the Moho around Beijing, Shijiazhuang and Guangrao where the deep faults join together shows a quadrantal distribution in some degree. The dynamic sources for seismic activity are the NE-SW horizontal compression and the diapirism of the upper mantle. The middle and upper crust, especially the layered block structure has the most significant effects on seismicity, and the occurrence of earthquakes is more closely related to them than to the Moho.展开更多
Firstly discovered in 1980s, human immunodeficiency virus (HIV) continues to affect more and more people. However, there is no effective drug available for the therapy of HIV infection. Betulinic acid existing in va...Firstly discovered in 1980s, human immunodeficiency virus (HIV) continues to affect more and more people. However, there is no effective drug available for the therapy of HIV infection. Betulinic acid existing in various medicinal herbs and fruits exhibits multiple biological effects, especially its outstanding anti-HIV activity, which has drawn the attentions of many pharmacists. Among the derivatives of betulinic acid, some compounds exhibited inhibitory activities at the nanomolar concentration, and have entered phase II clinical trials. This paper summarizes the current investigations on the anti-HIV activity of betulinic acid analogues, and provides valuable data for subsequent researches.展开更多
The title compound 2-(4-chlorophenyl)-1,3-dimethyl-2,3-dihydro-1H-perimidine(C(19)H(17)ClN2) was synthesized and characterized by elemental analysis, ^1H NMR, HRMS and single-crystal X-ray diffraction. The cry...The title compound 2-(4-chlorophenyl)-1,3-dimethyl-2,3-dihydro-1H-perimidine(C(19)H(17)ClN2) was synthesized and characterized by elemental analysis, ^1H NMR, HRMS and single-crystal X-ray diffraction. The crystal of the title compound belongs to orthorhombic system,space group Pnma with a = 11.385(2), b = 12.170(2), c = 11.210(2)A, V = 1553.2(5)A^3, Z = 4, Dc =1.321 g/cm^3, m(Mo-Ka) = 0.244 mm^-1, F(000) = 648, S = 1.309, R = 0.0400 and w R(I 〉 2s(I)) =0.1065. X-ray diffraction results showed that the molecular structure is highly symmetric and the new-formed N-heterocyclic ring is non-planar. In addition, the biological experiment showed that the title compound showed inhibitory activities against fungi with varied potencies.展开更多
The title compound 2-((2-fluorobenzyl)thio)-5-(pyridin-4-yl)-1,3,4-oxadiazole(C_(14)H_(10)FN_3OS) was synthesized,and its structure was confirmed by ~1H NMR,MS,elemental analyses and X-ray diffraction. It ...The title compound 2-((2-fluorobenzyl)thio)-5-(pyridin-4-yl)-1,3,4-oxadiazole(C_(14)H_(10)FN_3OS) was synthesized,and its structure was confirmed by ~1H NMR,MS,elemental analyses and X-ray diffraction. It crystallizes in the monoclinic system,space group P21/n with a = 11.541(16),b = 8.226(12),c = 13.683(19) ?,β = 94.872(17)o,V = 1294(3) ?~3,Z = 4 and R = 0.0648 for 2198 observed reflections with I 〉 2σ(I). The preliminary biological test shows that the title compound has good activity against Pythium ultimum with inhibitory to be 100%.展开更多
2-Oxo-butyric acid salicylacylhydrazone dibenzyltin(IV) complexes 1 {[o-OHC6H4(O)C=N-N=C(Et)COO](CH3OH)[(C6H5CH2)2Sn]}2 and 2 {[o-OH-C6H4(O)C=N-N=C(Et)-COO](CH3OH)[(2,4-Cl2C6H3CH2)2Sn]}2 have been sy...2-Oxo-butyric acid salicylacylhydrazone dibenzyltin(IV) complexes 1 {[o-OHC6H4(O)C=N-N=C(Et)COO](CH3OH)[(C6H5CH2)2Sn]}2 and 2 {[o-OH-C6H4(O)C=N-N=C(Et)-COO](CH3OH)[(2,4-Cl2C6H3CH2)2Sn]}2 have been synthesized. The complexes were characterized by IR, 1H, 13C and 119Sn NMR spectra, elemental analysis and thermal stability analysis, and the crystal structures were determined by X-ray diffraction. The crystal of complex 1 belongs to triclinic system, space group P1 with a = 8.9121(6), b = 10.3875(7), c = 14.5658(10) ?, α = 89.534(5), β = 86.790(5), γ = 70.103(6)°, Z = 1, V = 1265.85(15) ?3, Dc = 1.488 Mg·m^(-3), m(Mo Kα) = 1.047 mm-1, F(000) = 576, R = 0.0466 and w R = 0.1054. The crystal of complex 2 belongs to monoclinic system, space group P21/n, a = 12.7165(10), b = 17.8466(14), c = 12.8538(10) ?, β = 95.1310(10)°, Z = 2, V = 2905.4(4) ?~3, Dc = 1.612 Mg·m^(-3), m(Mo Kα) = 1.286 mm-1, F(000) = 1408, R = 0.0369 and w R = 0.0958. In vitro antitumor activities of both complexes were evaluated by the 3-(4,5-dimethylthiazoly-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay against three human cancer cell lines(NCI-H460, HepG2, MCF7) and one human cell line(HL7702). Two complexes exhibited strong antitumor activity, and then they were expected after further chemical optimization of candidate compounds as anti-cancer drugs. The interaction between complexes and calf thymus DNA were studied by EB fluorescent probe. The interactions of the two complexes with calf thymus DNA were intercalation.展开更多
Two new pleuromutilin derivatives, 14-O-[(4-amino-6-methoxyl-pyrimidine-2-yl)-thioacetyl] mutilin(4) and 14-O-[4-amino-1-methyl-6-oxo-1,6-dihydropyrimidin-2-yl)thioacetyl] mutilin(5), were synthesized and struc...Two new pleuromutilin derivatives, 14-O-[(4-amino-6-methoxyl-pyrimidine-2-yl)-thioacetyl] mutilin(4) and 14-O-[4-amino-1-methyl-6-oxo-1,6-dihydropyrimidin-2-yl)thioacetyl] mutilin(5), were synthesized and structurally characterized by IR, NMR spectra, HRMS and single-crystal X-ray diffraction. These compounds contain a 5-6-8 tricyclic carbon skeleton and a pyrimidine ring. Compound 4 is in the monoclinic system, space group P1211 with a = 10.2517(4), b = 12.5655(4), c = 10.3435(4)A, V = 1315.69(8) A^3, Z = 2, Dc = 1.309 g/cm3, F(000) = 558, μ = 0.166 mm^-1, S = 1.047, R = 0.0457 and w R = 0.0934 for 4721 unique reflections(R(int) = 0.0322) with I 〉 2σ(I). Compound 5 belongs to the orthorhombic system, space group P212121 with a = 7.3667(4), b = 13.9990(7), c = 29.0434(13) A, V = 2995.1(2) A^3, Z = 4, Dc = 1.250 g/cm^3, F(000) = 1216, μ = 0.153 mm^-1, S = 1.031, R = 0.0545 and wR = 0.0982 for 5242 unique reflections(R(int) = 0.0476) with I 〉 2σ(I)). The in vitro antibacterial activity study showed the title compounds 4 and 5 displayed slightly less activity against methicillin-resistant Staphylococcus aureus(MRSA) and methicillin-resistant Staphylococcus epidermidis(MRSE), and lower potent against Escherichia coli(E.coli) and Bacillus subtilis(B.subtilis) when compared to those of tiamulin fumarate.展开更多
The title compound 2-(1-(3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carbonyl)piperidin-4-yl)-N-isopropylthiazole-4-carboxamide(C21H22Br Cl N6O2 S,Mr = 536.04) has been synthesized,and its structure was cha...The title compound 2-(1-(3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carbonyl)piperidin-4-yl)-N-isopropylthiazole-4-carboxamide(C21H22Br Cl N6O2 S,Mr = 536.04) has been synthesized,and its structure was characterized by IR spectra,1H-NMR,13C-NMR,EA,and single-crystal X-ray diffraction.The crystal of the title compound belongs to monoclinic system,space group P/c with a = 15.146(3),b = 11.573(2),c = 26.937(5) A,β = 103.64(3)°,V = 1839.0(6) A^3,Z = 4,Dc = 1.557 g/cm^3,μ(Mo Ka) = 0.71073 mm^-1,F(000) = 2192,R = 0.0601 and w R = 0.1392.There exist one intramolecular hydrogen bond at N–H···N and four intermolecular weak interactions at O(2)···H(1),Cl(1)···H(12),O(1)···Cl(1) and S(1)···O(2).Bioassay results indicated that the title compound had good fungicidal and antiviral activities against tobacco mosaic virus.展开更多
One novel spiro-compound(C_(26)H_(21)NO_3) has been synthesized and characterized by means of NMR spectroscopy,elemental analyses and X-ray diffraction. The single crystal belongs to the monoclinic system,space ...One novel spiro-compound(C_(26)H_(21)NO_3) has been synthesized and characterized by means of NMR spectroscopy,elemental analyses and X-ray diffraction. The single crystal belongs to the monoclinic system,space group P21/c with a = 8.8039(7),b = 24.123(2),c = 10.0751(9) ?,β = 108.403(3)°,M3r = 395.44,V = 2030.3(3) ?~3,Z = 4,D_c = 1.294 g/cm,F(000) = 832.0,μ = 0.085 mm^(-1),R = 0.0801 and wR = 0.2228. The title compound shows good activities against Micrococcus tetragenus,Bacillus cereus,Bacillus subtilis,Staphylococcus aureus,S.albus and Escherichia coli.展开更多
Compounds 1 (C15H17C1F3N303, Mr = 379) and 2 (C14H14C1F3N4OS, Mr = 378) have been synthesized and their crystal structures were determined by single-crystal X-ray diffraction. Crystal 1 belongs to the triclinic sy...Compounds 1 (C15H17C1F3N303, Mr = 379) and 2 (C14H14C1F3N4OS, Mr = 378) have been synthesized and their crystal structures were determined by single-crystal X-ray diffraction. Crystal 1 belongs to the triclinic system, space group P1 with a = 6.0223(19), b = 9.324(3), c = 15.936(5) A, a = 80.687(5), β= 87.289(5), ), = 86.097(5)°, V= 880.4(5) A3, Z = 2, Dc = 1.433 g/cm3,μ(MoKa) = 0.266 mm^-1, F(000) = 392, R = 0.0861 and wR = 0.1999 for 2022 observed reflections with I 〉 2o(/). Crystal 2 belongs to the triclinic system, space group PI with a = 7.7029(15), b = 8.3371(16), c = 14.410(3) A, a = 100.672(3), β= 103.168(3), ? = 98.726(3)°, V = 876.1(3) A3, Z = 2, Dc= 1.451 g/cm^3,μ(MoKa) = 0.379 mm^-1, F(000) = 388, R = 0.0672 and wR = 0.2105 for 2725 observed reflections with I 〉 2σ(I). Although the two compounds are similar with the same pyrazole and pyrethroid units, X-ray analysis reveals that their structures are completely different.展开更多
4-Methyl-2-(4-methylphenyl)-5-(2-thiazolinyl)-1,3-thiazole, a novel compound, was synthesized by the annulation of 5-hydroxyethylcarbamoyl-4-methyl-2-(4- methylphenyl)-1,3-thiazole with P2S5. 5-Hydroxyethylcarba...4-Methyl-2-(4-methylphenyl)-5-(2-thiazolinyl)-1,3-thiazole, a novel compound, was synthesized by the annulation of 5-hydroxyethylcarbamoyl-4-methyl-2-(4- methylphenyl)-1,3-thiazole with P2S5. 5-Hydroxyethylcarbamoyl-4-methyl-2-(4-methylphenyl)-1,3-thiazole was prepared from the starting material of p-tolunitrile. The newly synthesized compounds were characterized by elemental analysis, IR, NMR(^1H, ^13C) and MS spectra. Hence, the crystal of the title compound was obtained, and its structure was determined by X-ray diffraction analysis. The crystal belongs to the triclinic system, space group P1 with a = 7.354(4), b = 8.383(4), c = 11.543(6)A, α = 76.688(6), β = 72.299(6), γ = 88.157(6)°, V = 659.2(6) A^3, Z = 2, Mr = 274.39, Dc = 1.382 g/cm^3, μ = 0.386 mm^-1, F(000) = 288, R = 0.0586 and w R = 0.1808 for 2984 unique reflections with 2213 observed ones(I 〉 2σ(I)). The title compound was also screened for its antibacterial activities against Bacillus subtilis and Escherichia coli. The result indicates that the target compound presents potential antimicrobial activities, and that the minimum inhibitory concentration(MIC) values of the title compound against the two tested strains are both 62.5 μg/mL.展开更多
The title compound N-((2,6-difluorophenyl)carbamoyl)-1,3-dimethyl-1 H-pyrazole-4-carboxamide(C13H12F2N4O2) was synthesized, and its structure was confirmed by ^1H NMR,HRMS and X-ray diffraction. It crystallizes ...The title compound N-((2,6-difluorophenyl)carbamoyl)-1,3-dimethyl-1 H-pyrazole-4-carboxamide(C13H12F2N4O2) was synthesized, and its structure was confirmed by ^1H NMR,HRMS and X-ray diffraction. It crystallizes in the monoclinic system, space group P21/c with a = 9.50(2), b = 10.11(2), c = 14.07(3) A^°, β = 102.15(3)°, Dc = 1.480 g/cm^3, Z = 4, V = 1320(5) A^°3, the final R = 0.0789 and wR = 0.1860 for 1054 observed reflections with I 〉 2σ(I). The preliminary biological test shows that the title compound has weak antifungal activities.展开更多
Exploration of soil environmental characteristics governing soil microbial community structure and activity may improve our understanding of biogeochemical processes and soil quality. The impact of soil environmental ...Exploration of soil environmental characteristics governing soil microbial community structure and activity may improve our understanding of biogeochemical processes and soil quality. The impact of soil environmental characteristics especially organic carbon availability after 15-yr different organic and inorganic fertilizer inputs on soil bacterial community structure and functional metabolic diversity of soil microbial communities were evaluated in a 15-yr fertilizer experiment in Changping County, Beijing, China. The experiment was a wheat-maize rotation system which was established in 1991 including four different fertilizer treatments. These treatments included: a non-amended control(CK), a commonly used application rate of inorganic fertilizer treatment(NPK); a commonly used application rate of inorganic fertilizer with swine manure incorporated treatment(NPKM), and a commonly used application rate of inorganic fertilizer with maize straw incorporated treatment(NPKS). Denaturing gradient gel electrophoresis(DGGE) of the 16 S r RNA gene was used to determine the bacterial community structure and single carbon source utilization profiles were determined to characterize the microbial community functional metabolic diversity of different fertilizer treatments using Biolog Eco plates. The results indicated that long-term fertilized treatments significantly increased soil bacterial community structure compared to CK. The use of inorganic fertilizer with organic amendments incorporated for long term(NPKM, NPKS) significantly promoted soil bacterial structure than the application of inorganic fertilizer only(NPK), and NPKM treatment was the most important driver for increases in the soil microbial community richness(S) and structural diversity(H). Overall utilization of carbon sources by soil microbial communities(average well color development, AWCD) and microbial substrate utilization diversity and evenness indices(H' and E) indicated that long-term inorganic fertilizer with organic amendments incorporated(NPKM, NPKS) could significantly stimulate soil microbial metabolic activity and functional diversity relative to CK, while no differences of them were found between NPKS and NPK treatments. Principal component analysis(PCA) based on carbon source utilization profiles also showed significant separation of soil microbial community under long-term fertilization regimes and NPKM treatment was significantly separated from the other three treatments primarily according to the higher microbial utilization of carbohydrates, carboxylic acids, polymers, phenolic compounds, and amino acid, while higher utilization of amines/amides differed soil microbial community in NPKS treatment from those in the other three treatments. Redundancy analysis(RDA) indicated that soil organic carbon(SOC) availability, especially soil microbial biomass carbon(Cmic) and Cmic/SOC ratio are the key factors of soil environmental characteristics contributing to the increase of both soil microbial community structure and functional metabolic diversity in the long-term fertilization trial. Our results showed that long-term inorganic fertilizer and swine manure application could significantly improve soil bacterial community structure and soil microbial metabolic activity through the increases in SOC availability, which could provide insights into the sustainable management of China's soil resource.展开更多
The novel Schiff base(E)-8-chloro-NA-(4-(dimethylamino)benzylidene)-[1,2,4]triazolo[4,3-a]pyridine-3-carbohydrazide was synthesized and characterized by ^1H NMR,MS,elemental analysis and X-ray diffraction.The co...The novel Schiff base(E)-8-chloro-NA-(4-(dimethylamino)benzylidene)-[1,2,4]triazolo[4,3-a]pyridine-3-carbohydrazide was synthesized and characterized by ^1H NMR,MS,elemental analysis and X-ray diffraction.The compound crystallizes in the monoclinic space group P2_1/c with a = 7.091(2),b = 10.750(3),c = 21.380(6) A,β = 96.299(6)°,V = 1619.7(8) A^3,Z = 4 and R = 0.0351.Theoretical calculation of the title compound was carried out with the B3LYP/6-31 G basis set.The frontier orbital energy and atomic net charges were discussed.It is found that the experimental data show good agreement with the calculated values.And the compound exhibits good antifungal activity against Stemphylium lycopersici(Enjoji) Yamamoto.展开更多
文摘Some basic concepts about the active structures were firstly explained, and the main subjects to study in the field of active structure dynamics were synthesized. For the linear active structures, the annotations on the modes were done in detail. The physical meanings of the right and left eigenvectors were explained. The right eigenvectors are the modal shapes and the modal responses of an active structure depend on the left ones. The adjoint structure of an active structure was defined and the reciprocity theorem was interpreted. For two active structures, which are adjoint to each other and with the reciprocal gain-matrices, the right and left eigenvector are reciprocal. The relationship between an active structure and the corresponding passive structure is expressed with the transfer functions, which is employed to resolve the estimation problems.
文摘The basic concepts about the active structures and some attributes of the modes were presented in paper “Liner Active Structures and Modes]( I) ". The characteristics of the active discrete systems and active beams were discussed, especially, the stability of the active structures and the orthogonality of the eigenvectors. The notes about modes were portrayed by a model of a seven-storeyed building with sensors and actuators. The concept of the adjoint active structure was extended from the discrete systems to the beams that were the representations of the continuous structures. Two types of beams with different placements of the measuring and actuating systems were discussed in detail. One is the beam with the discrete sensors and actuators, and the other is the beam with distributed sensor and actuator function. The orthogonality conditions were derived with the modal shapes of the active beam and its adjoint active beam. An example shows that the variation of eigenvalues with feedback amplitude for the homo-configuration and non-homo-configuration active structures.
基金supported by the National Natural Science Foundation of China(U1905202,31972017,and 31771922)the National Key R&D Program of China(2018YFD0901006)+2 种基金the Fujian Major Project of Provincial Science&Technology Hall,China(2020NZ010008)the Open Project of the Key Laboratory of Refrigeration and Conditioning Aquatic Products Processing,Ministry of Agriculture and Rural Affairs,China(KLRCAPP2021-03)the Quanzhou Science&Technology Project,China(2019C085R)。
文摘Peptides are functional active fragments of proteins which can provide nutrients needed for human growth and development,and they also have unique physiological activity characteristics relative to proteins.Bioactive peptides contain a great deal of development potential.More specifically,food-derived bioactive peptides have the advantages of a wide variety of sources,unique structures,high efficiency and safety,so they have broad development prospects.This review provides an overview of the current advances regarding the preparation,functional characteristics,and structure–activity relationships of food-derived bioactive peptides.Moreover,the prospects for the future development and application of food-derived bioactive peptides are discussed.This review may provide a better understanding of foodderived bioactive peptides,and some constructive inspirations for further research and applications in the food industry.
基金The project supported by the National Natural Science Foundation of China(50278054)
文摘The polynomial matrix using the block coefficient matrix representation auto-regressive moving average(referred to as the PM-ARMA)model is constructed in this paper for actively controlled multi-degree-of-freedom(MDOF)structures with time-delay through equivalently transforming the preliminary state space realization into the new state space realization.The PM-ARMA model is a more general formulation with respect to the polynomial using the coefficient representation auto-regressive moving average(ARMA)model due to its capability to cope with actively controlled structures with any given structural degrees of freedom and any chosen number of sensors and actuators.(The sensors and actuators are required to maintain the identical number.)under any dimensional stationary stochastic excitation.
基金financially sponsored by the National Natural Science Foundation of China(Grant Nos.22075223,22179104)the State Key Laboratory of Advanced Technology for Materials Synthesis and Processing(Wuhan University of Technology)(2022-ZD-4)。
文摘Precisely tuning the spacing of the active centers on the atomic scale is of great significance to improve the catalytic activity and deepen the understanding of the catalytic mechanism,but still remains a challenge.Here,we develop a strategy to dilute catalytically active metal interatomic spacing(d_(M-M))with light atoms and discover the unusual adsorption patterns.For example,by elevating the content of boron as interstitial atoms,the atomic spacing of osmium(d_(Os-Os))gradually increases from 2.73 to 2.96?.More importantly,we find that,with the increase in dOs-Os,the hydrogen adsorption-distance relationship is reversed via downshifting d-band states,which breaks the traditional cognition,thereby optimizing the H adsorption and H_2O dissociation on the electrode surface during the catalytic process;this finally leads to a nearly linear increase in hydrogen evolution reaction activity.Namely,the maximum dOs-Os of 2.96?presents the optimal HER activity(8 mV@10 mA cm^(-2))in alkaline media as well as suppressed O adsorption and thus promoted stability.It is believed that this novel atomic-level distance modulation strategy of catalytic sites and the reversed hydrogen adsorption-distance relationship can shew new insights for optimal design of highly efficient catalysts.
文摘In this paper,the functional polymeric active materials were prepared by the grafting copolymerization and their structure and properties were studied.The results show that the structure and properties of these ac- tive materials have the relative large effects on the properties of gadolinium ion selective electrodes.
基金supported by the National Natural Science Foundation of China (No. 82074277 and 81773911)the Development Project of Shanghai Peak Disciplines-Integrated Medicine (No. 20180101)
文摘To utilize themultiple functions and give full play of ginsenosides,a variety of ginsenosides with different structures were prepared into liposomes and evaluated for their effect on the stability,pharmacokinetics and tumor targeting capability of liposomes.The results showed that the position and number of glycosyl groups of ginsenosides have significant effect on the in vitro and in vivo properties of their liposomes.The pharmacokinetics of ginsenosides liposomes indicated that the C-3 sugar group of ginsenosides is beneficial to their liposomes for longer circulation in vivo.The C-3 and C-6 glycosyls can enhance the uptake of their liposomes by 4T1 cells,and the glycosyls at C-3 position can enhance the tumor active targeting ability significantly,based on the specific binding capacity to Glut 1 expressed on the surface of 4T1 cells.According to the results in the study,ginsenoside Rg3 and ginsenoside Rh2 are potential for exploiting novel liposomes because of their cholesterol substitution,long blood circulation and tumor targeting capabilities.The results provide a theoretical basis for further development of ginsenoside based liposome delivery systems.
文摘A layered crustal block model of North China has been constructed based on large amount of data from seismic sounding carried out in recent two decades. Some deep fault zones, such as the Zhangjiakou.Penglai and Tancheng-Lujiang fault zones, divide the upper crust of North China into three upper crustal terranes and nine bolcks. There are distinct differences in velocity and depth distributions, which reflects Cenozoic block faulting in North China in the process of formation of the deep structure. The upper crust shows the features of transition in isostatic adjustment. The existence of a low-velocity layer in the middle crust is characteristic of the crustal structure in North China. There seems to be an increase of rheology of the rocks in the lower crust and a persistence of stable regional stress field. The patterns of the Moho on two sides of the Yanshan-Taihang Mountains are different. The relief of the Moho around Beijing, Shijiazhuang and Guangrao where the deep faults join together shows a quadrantal distribution in some degree. The dynamic sources for seismic activity are the NE-SW horizontal compression and the diapirism of the upper mantle. The middle and upper crust, especially the layered block structure has the most significant effects on seismicity, and the occurrence of earthquakes is more closely related to them than to the Moho.
基金This research was supported by the National Natural Science Foundation of China (No. 81273537), Scientific Research Fund of Education Department of Hunan Province (No. 17A190), the Key Project of Science and Technology Department of Hunan Province (No. 2016DK2001), and the Key Disciplines of Hunan Province and the Zhengxing Scholar Program of the University of South China.
文摘Firstly discovered in 1980s, human immunodeficiency virus (HIV) continues to affect more and more people. However, there is no effective drug available for the therapy of HIV infection. Betulinic acid existing in various medicinal herbs and fruits exhibits multiple biological effects, especially its outstanding anti-HIV activity, which has drawn the attentions of many pharmacists. Among the derivatives of betulinic acid, some compounds exhibited inhibitory activities at the nanomolar concentration, and have entered phase II clinical trials. This paper summarizes the current investigations on the anti-HIV activity of betulinic acid analogues, and provides valuable data for subsequent researches.
基金financially supported by the Science and Technology Planning Project of Hunan Province2015GK3037)the Scientific Research Fund of Hunan Provincial Education Department(14A058,13A030)
文摘The title compound 2-(4-chlorophenyl)-1,3-dimethyl-2,3-dihydro-1H-perimidine(C(19)H(17)ClN2) was synthesized and characterized by elemental analysis, ^1H NMR, HRMS and single-crystal X-ray diffraction. The crystal of the title compound belongs to orthorhombic system,space group Pnma with a = 11.385(2), b = 12.170(2), c = 11.210(2)A, V = 1553.2(5)A^3, Z = 4, Dc =1.321 g/cm^3, m(Mo-Ka) = 0.244 mm^-1, F(000) = 648, S = 1.309, R = 0.0400 and w R(I 〉 2s(I)) =0.1065. X-ray diffraction results showed that the molecular structure is highly symmetric and the new-formed N-heterocyclic ring is non-planar. In addition, the biological experiment showed that the title compound showed inhibitory activities against fungi with varied potencies.
基金funded by the Natural Science Foundation of Zhejiang Province(No.LY16C140007)the program of Science and Technology of Jiangsu Province(BY2014108-14)
文摘The title compound 2-((2-fluorobenzyl)thio)-5-(pyridin-4-yl)-1,3,4-oxadiazole(C_(14)H_(10)FN_3OS) was synthesized,and its structure was confirmed by ~1H NMR,MS,elemental analyses and X-ray diffraction. It crystallizes in the monoclinic system,space group P21/n with a = 11.541(16),b = 8.226(12),c = 13.683(19) ?,β = 94.872(17)o,V = 1294(3) ?~3,Z = 4 and R = 0.0648 for 2198 observed reflections with I 〉 2σ(I). The preliminary biological test shows that the title compound has good activity against Pythium ultimum with inhibitory to be 100%.
基金Supported by Natural Science Foundation of Hunan Province(No.2016JJ4008)the Innovation Platform Open Fund Project of Hunan Provincial Education Department of China(No.16K011)+1 种基金the Open Fund Project of Key Laboratory of Functional Organometallic Materials of Hengyang Normal University(Nos.GN16k01,GN16K03)the Scientific and Technological Projects of Hengyang(No.2016KJ04)
文摘2-Oxo-butyric acid salicylacylhydrazone dibenzyltin(IV) complexes 1 {[o-OHC6H4(O)C=N-N=C(Et)COO](CH3OH)[(C6H5CH2)2Sn]}2 and 2 {[o-OH-C6H4(O)C=N-N=C(Et)-COO](CH3OH)[(2,4-Cl2C6H3CH2)2Sn]}2 have been synthesized. The complexes were characterized by IR, 1H, 13C and 119Sn NMR spectra, elemental analysis and thermal stability analysis, and the crystal structures were determined by X-ray diffraction. The crystal of complex 1 belongs to triclinic system, space group P1 with a = 8.9121(6), b = 10.3875(7), c = 14.5658(10) ?, α = 89.534(5), β = 86.790(5), γ = 70.103(6)°, Z = 1, V = 1265.85(15) ?3, Dc = 1.488 Mg·m^(-3), m(Mo Kα) = 1.047 mm-1, F(000) = 576, R = 0.0466 and w R = 0.1054. The crystal of complex 2 belongs to monoclinic system, space group P21/n, a = 12.7165(10), b = 17.8466(14), c = 12.8538(10) ?, β = 95.1310(10)°, Z = 2, V = 2905.4(4) ?~3, Dc = 1.612 Mg·m^(-3), m(Mo Kα) = 1.286 mm-1, F(000) = 1408, R = 0.0369 and w R = 0.0958. In vitro antitumor activities of both complexes were evaluated by the 3-(4,5-dimethylthiazoly-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay against three human cancer cell lines(NCI-H460, HepG2, MCF7) and one human cell line(HL7702). Two complexes exhibited strong antitumor activity, and then they were expected after further chemical optimization of candidate compounds as anti-cancer drugs. The interaction between complexes and calf thymus DNA were studied by EB fluorescent probe. The interactions of the two complexes with calf thymus DNA were intercalation.
基金Basic Scientific Research Funds in Central Agricultural Scientific Research Institutions(No.1610322014003)the Agricultural Science and Technology Innovation Program(ASTIP,No.CAAS-ASTIP-2014-LIHPS-04)
文摘Two new pleuromutilin derivatives, 14-O-[(4-amino-6-methoxyl-pyrimidine-2-yl)-thioacetyl] mutilin(4) and 14-O-[4-amino-1-methyl-6-oxo-1,6-dihydropyrimidin-2-yl)thioacetyl] mutilin(5), were synthesized and structurally characterized by IR, NMR spectra, HRMS and single-crystal X-ray diffraction. These compounds contain a 5-6-8 tricyclic carbon skeleton and a pyrimidine ring. Compound 4 is in the monoclinic system, space group P1211 with a = 10.2517(4), b = 12.5655(4), c = 10.3435(4)A, V = 1315.69(8) A^3, Z = 2, Dc = 1.309 g/cm3, F(000) = 558, μ = 0.166 mm^-1, S = 1.047, R = 0.0457 and w R = 0.0934 for 4721 unique reflections(R(int) = 0.0322) with I 〉 2σ(I). Compound 5 belongs to the orthorhombic system, space group P212121 with a = 7.3667(4), b = 13.9990(7), c = 29.0434(13) A, V = 2995.1(2) A^3, Z = 4, Dc = 1.250 g/cm^3, F(000) = 1216, μ = 0.153 mm^-1, S = 1.031, R = 0.0545 and wR = 0.0982 for 5242 unique reflections(R(int) = 0.0476) with I 〉 2σ(I)). The in vitro antibacterial activity study showed the title compounds 4 and 5 displayed slightly less activity against methicillin-resistant Staphylococcus aureus(MRSA) and methicillin-resistant Staphylococcus epidermidis(MRSE), and lower potent against Escherichia coli(E.coli) and Bacillus subtilis(B.subtilis) when compared to those of tiamulin fumarate.
基金funded in part by the National Natural Science Foundation of China(21372132)NFFTBS(No.J1103306)
文摘The title compound 2-(1-(3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carbonyl)piperidin-4-yl)-N-isopropylthiazole-4-carboxamide(C21H22Br Cl N6O2 S,Mr = 536.04) has been synthesized,and its structure was characterized by IR spectra,1H-NMR,13C-NMR,EA,and single-crystal X-ray diffraction.The crystal of the title compound belongs to monoclinic system,space group P/c with a = 15.146(3),b = 11.573(2),c = 26.937(5) A,β = 103.64(3)°,V = 1839.0(6) A^3,Z = 4,Dc = 1.557 g/cm^3,μ(Mo Ka) = 0.71073 mm^-1,F(000) = 2192,R = 0.0601 and w R = 0.1392.There exist one intramolecular hydrogen bond at N–H···N and four intermolecular weak interactions at O(2)···H(1),Cl(1)···H(12),O(1)···Cl(1) and S(1)···O(2).Bioassay results indicated that the title compound had good fungicidal and antiviral activities against tobacco mosaic virus.
基金Project supported by the Natural Science Foundation of Hainan Province(No.20162033)the Cultivation Research Foundation of Hainan Medical University(HY2015-02)
文摘One novel spiro-compound(C_(26)H_(21)NO_3) has been synthesized and characterized by means of NMR spectroscopy,elemental analyses and X-ray diffraction. The single crystal belongs to the monoclinic system,space group P21/c with a = 8.8039(7),b = 24.123(2),c = 10.0751(9) ?,β = 108.403(3)°,M3r = 395.44,V = 2030.3(3) ?~3,Z = 4,D_c = 1.294 g/cm,F(000) = 832.0,μ = 0.085 mm^(-1),R = 0.0801 and wR = 0.2228. The title compound shows good activities against Micrococcus tetragenus,Bacillus cereus,Bacillus subtilis,Staphylococcus aureus,S.albus and Escherichia coli.
基金supported by Hubei University of Technology,Science and Technology Department of Hubei Province(No.ZRY0981)National Natural Science Foundation of China(No.21272086)
文摘Compounds 1 (C15H17C1F3N303, Mr = 379) and 2 (C14H14C1F3N4OS, Mr = 378) have been synthesized and their crystal structures were determined by single-crystal X-ray diffraction. Crystal 1 belongs to the triclinic system, space group P1 with a = 6.0223(19), b = 9.324(3), c = 15.936(5) A, a = 80.687(5), β= 87.289(5), ), = 86.097(5)°, V= 880.4(5) A3, Z = 2, Dc = 1.433 g/cm3,μ(MoKa) = 0.266 mm^-1, F(000) = 392, R = 0.0861 and wR = 0.1999 for 2022 observed reflections with I 〉 2o(/). Crystal 2 belongs to the triclinic system, space group PI with a = 7.7029(15), b = 8.3371(16), c = 14.410(3) A, a = 100.672(3), β= 103.168(3), ? = 98.726(3)°, V = 876.1(3) A3, Z = 2, Dc= 1.451 g/cm^3,μ(MoKa) = 0.379 mm^-1, F(000) = 388, R = 0.0672 and wR = 0.2105 for 2725 observed reflections with I 〉 2σ(I). Although the two compounds are similar with the same pyrazole and pyrethroid units, X-ray analysis reveals that their structures are completely different.
基金supported by the Open-end Funds of Jiangsu Key Laboratory of Marine Biotechnology,Huaihai Institute of Technology(2013HS004)Open-end Funds of Jiangsu Key Laboratory of Marine Pharmaceutical Compound Screening(2015HYB05)a project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(201402)
文摘4-Methyl-2-(4-methylphenyl)-5-(2-thiazolinyl)-1,3-thiazole, a novel compound, was synthesized by the annulation of 5-hydroxyethylcarbamoyl-4-methyl-2-(4- methylphenyl)-1,3-thiazole with P2S5. 5-Hydroxyethylcarbamoyl-4-methyl-2-(4-methylphenyl)-1,3-thiazole was prepared from the starting material of p-tolunitrile. The newly synthesized compounds were characterized by elemental analysis, IR, NMR(^1H, ^13C) and MS spectra. Hence, the crystal of the title compound was obtained, and its structure was determined by X-ray diffraction analysis. The crystal belongs to the triclinic system, space group P1 with a = 7.354(4), b = 8.383(4), c = 11.543(6)A, α = 76.688(6), β = 72.299(6), γ = 88.157(6)°, V = 659.2(6) A^3, Z = 2, Mr = 274.39, Dc = 1.382 g/cm^3, μ = 0.386 mm^-1, F(000) = 288, R = 0.0586 and w R = 0.1808 for 2984 unique reflections with 2213 observed ones(I 〉 2σ(I)). The title compound was also screened for its antibacterial activities against Bacillus subtilis and Escherichia coli. The result indicates that the target compound presents potential antimicrobial activities, and that the minimum inhibitory concentration(MIC) values of the title compound against the two tested strains are both 62.5 μg/mL.
基金funded by Natural Science Foundation of Zhejiang Province(No.LY16C140007)National Natural Science Foundation of China(No.31401691)
文摘The title compound N-((2,6-difluorophenyl)carbamoyl)-1,3-dimethyl-1 H-pyrazole-4-carboxamide(C13H12F2N4O2) was synthesized, and its structure was confirmed by ^1H NMR,HRMS and X-ray diffraction. It crystallizes in the monoclinic system, space group P21/c with a = 9.50(2), b = 10.11(2), c = 14.07(3) A^°, β = 102.15(3)°, Dc = 1.480 g/cm^3, Z = 4, V = 1320(5) A^°3, the final R = 0.0789 and wR = 0.1860 for 1054 observed reflections with I 〉 2σ(I). The preliminary biological test shows that the title compound has weak antifungal activities.
基金funded by the National Natural Science Foundation of China(NSFC31301843)the National Nonprofit Institute Research Grant of Chinese Academy of Agricultural Sciences(IARRP-202-5)
文摘Exploration of soil environmental characteristics governing soil microbial community structure and activity may improve our understanding of biogeochemical processes and soil quality. The impact of soil environmental characteristics especially organic carbon availability after 15-yr different organic and inorganic fertilizer inputs on soil bacterial community structure and functional metabolic diversity of soil microbial communities were evaluated in a 15-yr fertilizer experiment in Changping County, Beijing, China. The experiment was a wheat-maize rotation system which was established in 1991 including four different fertilizer treatments. These treatments included: a non-amended control(CK), a commonly used application rate of inorganic fertilizer treatment(NPK); a commonly used application rate of inorganic fertilizer with swine manure incorporated treatment(NPKM), and a commonly used application rate of inorganic fertilizer with maize straw incorporated treatment(NPKS). Denaturing gradient gel electrophoresis(DGGE) of the 16 S r RNA gene was used to determine the bacterial community structure and single carbon source utilization profiles were determined to characterize the microbial community functional metabolic diversity of different fertilizer treatments using Biolog Eco plates. The results indicated that long-term fertilized treatments significantly increased soil bacterial community structure compared to CK. The use of inorganic fertilizer with organic amendments incorporated for long term(NPKM, NPKS) significantly promoted soil bacterial structure than the application of inorganic fertilizer only(NPK), and NPKM treatment was the most important driver for increases in the soil microbial community richness(S) and structural diversity(H). Overall utilization of carbon sources by soil microbial communities(average well color development, AWCD) and microbial substrate utilization diversity and evenness indices(H' and E) indicated that long-term inorganic fertilizer with organic amendments incorporated(NPKM, NPKS) could significantly stimulate soil microbial metabolic activity and functional diversity relative to CK, while no differences of them were found between NPKS and NPK treatments. Principal component analysis(PCA) based on carbon source utilization profiles also showed significant separation of soil microbial community under long-term fertilization regimes and NPKM treatment was significantly separated from the other three treatments primarily according to the higher microbial utilization of carbohydrates, carboxylic acids, polymers, phenolic compounds, and amino acid, while higher utilization of amines/amides differed soil microbial community in NPKS treatment from those in the other three treatments. Redundancy analysis(RDA) indicated that soil organic carbon(SOC) availability, especially soil microbial biomass carbon(Cmic) and Cmic/SOC ratio are the key factors of soil environmental characteristics contributing to the increase of both soil microbial community structure and functional metabolic diversity in the long-term fertilization trial. Our results showed that long-term inorganic fertilizer and swine manure application could significantly improve soil bacterial community structure and soil microbial metabolic activity through the increases in SOC availability, which could provide insights into the sustainable management of China's soil resource.
基金funded by National Natural Science Foundation of China(No.21002090)Zhejiang Provincial Natural Science Foundation of China(No.LY16C140007)the National Key Technologies R&D Program(2011BAE06B03-01)
文摘The novel Schiff base(E)-8-chloro-NA-(4-(dimethylamino)benzylidene)-[1,2,4]triazolo[4,3-a]pyridine-3-carbohydrazide was synthesized and characterized by ^1H NMR,MS,elemental analysis and X-ray diffraction.The compound crystallizes in the monoclinic space group P2_1/c with a = 7.091(2),b = 10.750(3),c = 21.380(6) A,β = 96.299(6)°,V = 1619.7(8) A^3,Z = 4 and R = 0.0351.Theoretical calculation of the title compound was carried out with the B3LYP/6-31 G basis set.The frontier orbital energy and atomic net charges were discussed.It is found that the experimental data show good agreement with the calculated values.And the compound exhibits good antifungal activity against Stemphylium lycopersici(Enjoji) Yamamoto.