Semiaquilegia adoxoides ( DC. ) Makino ( Chinese name ''Tian-Kui-Zi'' ) , theonly species of genus Semiaquilegia, belongs to the Ranunculaceae family. As a perennial herbaceousplant, both the aerial pa...Semiaquilegia adoxoides ( DC. ) Makino ( Chinese name ''Tian-Kui-Zi'' ) , theonly species of genus Semiaquilegia, belongs to the Ranunculaceae family. As a perennial herbaceousplant, both the aerial parts and the roots are used in traditional Chinese medicine for differentmedications. The roots are often used to treat inflammation, snake bite, bruises and injuries,tonsillitis, mastitis, scrofula, and cancer for their antibacterial, anti-inflammatory, andantineoplastic activities. The aerial parts are used for the treatment of mastitis, bruises, andheart diseases, such as endomyocarditis. The medicinal usage of this plant prompted us toinvestigate its chemical constituents. As a result, nine compounds 1-9 ( see Figure 1) were isolatedfrom the roots of S. adoxoides. Among them, compounds 1-7 and 9 were isolated from the genusSemiaquilegia for the first time.展开更多
Multishell nanotubes of polyaniline and carbon were synthesized via a template approach. A thin layer of MnO2 coated on carbon nanotubes acts as a reactive template for the consequent formation of the polyaniline coat...Multishell nanotubes of polyaniline and carbon were synthesized via a template approach. A thin layer of MnO2 coated on carbon nanotubes acts as a reactive template for the consequent formation of the polyaniline coating. The polyaniline-carbon nanotubes show enhanced dispersibility in water and can be possibly used as a functional material of electrochemical capacitors with improved performance. The general method operates by coating carbon nanotubes on functional materials such as poly （3,4-ethylenedioxythiophene）, polypyrrole, silica, and carbon.展开更多
The structural relaxation of a cluster containing 55 atoms at elevated temperatures is simulated by molecular dynamics. The interatomic interactions are given by using the embedded atom method （EAM） potential. By de...The structural relaxation of a cluster containing 55 atoms at elevated temperatures is simulated by molecular dynamics. The interatomic interactions are given by using the embedded atom method （EAM） potential. By decomposing the peaks of the radial distribution functions （RDFs） according to the pair analysis technique, the local structural patterns are identified for this cluster. During increasing temperature, structural changes of different shells determined by atom density profiles result in an abrupt increase in internal energy. The simulations show how local structural changes can strongly cause internal energy to change accordingly.展开更多
Aim To investigate the structure of mogroside Ⅳa isolated from traditionalChinese medicine fructus mo-mordicae [fruits of Siraitia grosvenori (Swingle) C. Jeffery] andsummarize the NMR characteristics of the structur...Aim To investigate the structure of mogroside Ⅳa isolated from traditionalChinese medicine fructus mo-mordicae [fruits of Siraitia grosvenori (Swingle) C. Jeffery] andsummarize the NMR characteristics of the structure. Methods Common extraction, separation andpurification methods were used. Various NMR techniques including ~1H NMR, ^(13)C NMR, DEPT, ~1H-~1HCOSY, HSQC, HMBC, NOESY and molecular model simulated by computer were used to elucidate thestructure. Results ~1H and ^(13)C NMR signals of mogroside Ⅳa were assigned, and spectroscopicbasis was obtained for identification of such type of compounds. Conclusion 1D and 2D NMR techniquesincluding ~1H-~1H COSY, HSQC, HMBC, NOESY spectra are powerful tools for structure analysis. Thestructure determined by NMR methods is identical with energy minimized conformation simulated bycomputer.展开更多
Four-, six-, and eight-membered ring silica nanotubes at temperatures from 300 K to 1600 K are relaxed by classical molecular dynamics simulations with three potential models. The simulation results indicate that the ...Four-, six-, and eight-membered ring silica nanotubes at temperatures from 300 K to 1600 K are relaxed by classical molecular dynamics simulations with three potential models. The simulation results indicate that the stability of the end rings of the three silica nanotubes gradually decreases with increase in temperature. The validity of the vibrational features of silica nanotubes is shown by the vibrational density of states. Infrared spectra on the silica nanotubes under different temperatures are investigated. A detailed assignment of each spectral peak to the corresponding vibrational mode of the three nanotubes has been addressed. The results are in good agreement with the other theoretical and experimental展开更多
Study of geometries of 16 possible isomers for C76N2 based on C78(C2v) by intermediate neglect of differential overlap (INDO) series of methods indicated that the most stable geometry 25,78-C76N2 where two nitrogen at...Study of geometries of 16 possible isomers for C76N2 based on C78(C2v) by intermediate neglect of differential overlap (INDO) series of methods indicated that the most stable geometry 25,78-C76N2 where two nitrogen atoms substitute two apexes C(25) and C(78) near the shortest X axis and Y axis formed by two hexagons and a pentagon. Electronic structures and spectra of C76N2 were investigated. The reason for the red-shift for absorptions of C76N2 compared with that of C78(C2v) is discussed.展开更多
基金Ministry of Science and Technology of People'sRepublic of China (No. 2004AA2Z3730)
文摘Semiaquilegia adoxoides ( DC. ) Makino ( Chinese name ''Tian-Kui-Zi'' ) , theonly species of genus Semiaquilegia, belongs to the Ranunculaceae family. As a perennial herbaceousplant, both the aerial parts and the roots are used in traditional Chinese medicine for differentmedications. The roots are often used to treat inflammation, snake bite, bruises and injuries,tonsillitis, mastitis, scrofula, and cancer for their antibacterial, anti-inflammatory, andantineoplastic activities. The aerial parts are used for the treatment of mastitis, bruises, andheart diseases, such as endomyocarditis. The medicinal usage of this plant prompted us toinvestigate its chemical constituents. As a result, nine compounds 1-9 ( see Figure 1) were isolatedfrom the roots of S. adoxoides. Among them, compounds 1-7 and 9 were isolated from the genusSemiaquilegia for the first time.
基金ACKNOWLEDGMENTS This work was supported by the National Key Fundamental Research Project （No.2007CB936300）,the National Natural Science Foundation of China （No.60706019, No.60990314, No.60928009, and No.61076017）, the Natural Science Foundation of Jiangsu Province （BK2008025）, and the New Century Excellent Talents-430.
文摘Multishell nanotubes of polyaniline and carbon were synthesized via a template approach. A thin layer of MnO2 coated on carbon nanotubes acts as a reactive template for the consequent formation of the polyaniline coating. The polyaniline-carbon nanotubes show enhanced dispersibility in water and can be possibly used as a functional material of electrochemical capacitors with improved performance. The general method operates by coating carbon nanotubes on functional materials such as poly （3,4-ethylenedioxythiophene）, polypyrrole, silica, and carbon.
基金Project supported by the National Natural Science Foundation of China （Grant No 50572013） and the National Basic Research Program of China （Grant No 2006CB605103）. Corresponding author.
文摘The structural relaxation of a cluster containing 55 atoms at elevated temperatures is simulated by molecular dynamics. The interatomic interactions are given by using the embedded atom method （EAM） potential. By decomposing the peaks of the radial distribution functions （RDFs） according to the pair analysis technique, the local structural patterns are identified for this cluster. During increasing temperature, structural changes of different shells determined by atom density profiles result in an abrupt increase in internal energy. The simulations show how local structural changes can strongly cause internal energy to change accordingly.
文摘Aim To investigate the structure of mogroside Ⅳa isolated from traditionalChinese medicine fructus mo-mordicae [fruits of Siraitia grosvenori (Swingle) C. Jeffery] andsummarize the NMR characteristics of the structure. Methods Common extraction, separation andpurification methods were used. Various NMR techniques including ~1H NMR, ^(13)C NMR, DEPT, ~1H-~1HCOSY, HSQC, HMBC, NOESY and molecular model simulated by computer were used to elucidate thestructure. Results ~1H and ^(13)C NMR signals of mogroside Ⅳa were assigned, and spectroscopicbasis was obtained for identification of such type of compounds. Conclusion 1D and 2D NMR techniquesincluding ~1H-~1H COSY, HSQC, HMBC, NOESY spectra are powerful tools for structure analysis. Thestructure determined by NMR methods is identical with energy minimized conformation simulated bycomputer.
文摘Four-, six-, and eight-membered ring silica nanotubes at temperatures from 300 K to 1600 K are relaxed by classical molecular dynamics simulations with three potential models. The simulation results indicate that the stability of the end rings of the three silica nanotubes gradually decreases with increase in temperature. The validity of the vibrational features of silica nanotubes is shown by the vibrational density of states. Infrared spectra on the silica nanotubes under different temperatures are investigated. A detailed assignment of each spectral peak to the corresponding vibrational mode of the three nanotubes has been addressed. The results are in good agreement with the other theoretical and experimental
文摘Study of geometries of 16 possible isomers for C76N2 based on C78(C2v) by intermediate neglect of differential overlap (INDO) series of methods indicated that the most stable geometry 25,78-C76N2 where two nitrogen atoms substitute two apexes C(25) and C(78) near the shortest X axis and Y axis formed by two hexagons and a pentagon. Electronic structures and spectra of C76N2 were investigated. The reason for the red-shift for absorptions of C76N2 compared with that of C78(C2v) is discussed.
