In Chlorella vulgaris Beg. and Cladophora sp. treated with different concentrations of r-BHC and p,p-DDT, the protein and free amino acid content in both were higher than those in the controls, and the free amino acid...In Chlorella vulgaris Beg. and Cladophora sp. treated with different concentrations of r-BHC and p,p-DDT, the protein and free amino acid content in both were higher than those in the controls, and the free amino acid content was even higher than the protein amino acid content.展开更多
An efficient synthesis ofα-D-GlcpNAc-（1→2）-[α-D-ManpNAc-（1→3）-]α-L-Rhap-（1→2）-α-L-Rhap-（1→3）-α-L-Rhap（1）, the repeating unit of the O10 antigen from Acinetobacter baumannii was achieved via sequenti...An efficient synthesis ofα-D-GlcpNAc-（1→2）-[α-D-ManpNAc-（1→3）-]α-L-Rhap-（1→2）-α-L-Rhap-（1→3）-α-L-Rhap（1）, the repeating unit of the O10 antigen from Acinetobacter baumannii was achieved via sequential assembly of the building blocks,p- methoxylphenyl 2,4-di-O-benzoyl-α-L-rhamnopyranoside（2）;2-O-allyloxycarbonyl-3,4-di-O-bcnzoyl-α-L-rhamnopyranosyl tri- chloroacetimidate（3）;4-methoxylphenyl 3-O-allyloxycarbonyl-4-O-benzoyl-α-L-rhanmopyranoside（4）;2-azido-3-O-benzoyl-2- deoxy-4,6-O-isopropylidene-α-D-mannopyranosyl trichloroacetirnidatc（5）;2-azido-3,4,6-tri-O-benzoyl-2-deoxy-α,β-D-glucopyr- ano syl trichloroacetimidatc（6）.The total yield of 1 from 4 was 4.7%.展开更多
Highly efficient removal of allyloxycarbonyl （Alloc） group was achieved in the presence of CH3COONH4, Pd[P（C6H5）3]4, and NaBH4 in MeOH-THF, within 5 min in almost quantitative yields （〉90%, isolated yield） with...Highly efficient removal of allyloxycarbonyl （Alloc） group was achieved in the presence of CH3COONH4, Pd[P（C6H5）3]4, and NaBH4 in MeOH-THF, within 5 min in almost quantitative yields （〉90%, isolated yield） without affecting acetyl, benzoyl, isopropylidene, benzylidene, allyl, benzyl, benzyl carbonate, or azido groups.展开更多
The electronic structures of C_(60) ahd C_(60) M(M=Li,Na,K,Rb and Cs)were calculated by using an atom superposition and electron delocalization molecular orbital method.The results indicate that s valence electron of ...The electronic structures of C_(60) ahd C_(60) M(M=Li,Na,K,Rb and Cs)were calculated by using an atom superposition and electron delocalization molecular orbital method.The results indicate that s valence electron of the atom of alkali metal was completely transferred to 5T_(1u) orbital of C_(60).The stabilization energy of the system results mainly from the electrostatic interaction between polarized C_(60) and alkali metal atom.展开更多
Hydrogen peroxide (H2O2 ) concentrations were measured at two sites. One was on Lushan Mountain in May, 1987. The other was in Beijing in August, 1987 and in December, 1986. The automated fluorometric method was used ...Hydrogen peroxide (H2O2 ) concentrations were measured at two sites. One was on Lushan Mountain in May, 1987. The other was in Beijing in August, 1987 and in December, 1986. The automated fluorometric method was used for the determination of H2O2 . The concentrations of H2O2 ranged from approximately 0.50 to 4.32 ppb on Lushan Mountain. The concentrations of H2O2 ranged from approximately 0.05 to 1.49 ppb in August in Beijing, and it was only 0.01 ppb in December in Beijing.展开更多
Glycoconjugate, as a carrier of message, has important biological functions. The sugar moiety contains surprising information. Its molecular structure has been paid increasing attention to since the 1980’s. The appli...Glycoconjugate, as a carrier of message, has important biological functions. The sugar moiety contains surprising information. Its molecular structure has been paid increasing attention to since the 1980’s. The application of softionization techniques, such as展开更多
The primary conservation objective in China is to establish nature reserves to protect biological resources and natural heritage, protect ecosystems which are of global importance or have unique regional features, pro...The primary conservation objective in China is to establish nature reserves to protect biological resources and natural heritage, protect ecosystems which are of global importance or have unique regional features, protect endangered and threatened species and their habitat, and safeguard the genetic resources. By 2000, the number of nature reserves increased to 1,276, while at the same time, the total area protected in nature reserves was up to 123 million ha. Of the total number of reserves, 908 sites ...展开更多
文摘In Chlorella vulgaris Beg. and Cladophora sp. treated with different concentrations of r-BHC and p,p-DDT, the protein and free amino acid content in both were higher than those in the controls, and the free amino acid content was even higher than the protein amino acid content.
文摘An efficient synthesis ofα-D-GlcpNAc-（1→2）-[α-D-ManpNAc-（1→3）-]α-L-Rhap-（1→2）-α-L-Rhap-（1→3）-α-L-Rhap（1）, the repeating unit of the O10 antigen from Acinetobacter baumannii was achieved via sequential assembly of the building blocks,p- methoxylphenyl 2,4-di-O-benzoyl-α-L-rhamnopyranoside（2）;2-O-allyloxycarbonyl-3,4-di-O-bcnzoyl-α-L-rhamnopyranosyl tri- chloroacetimidate（3）;4-methoxylphenyl 3-O-allyloxycarbonyl-4-O-benzoyl-α-L-rhanmopyranoside（4）;2-azido-3-O-benzoyl-2- deoxy-4,6-O-isopropylidene-α-D-mannopyranosyl trichloroacetirnidatc（5）;2-azido-3,4,6-tri-O-benzoyl-2-deoxy-α,β-D-glucopyr- ano syl trichloroacetimidatc（6）.The total yield of 1 from 4 was 4.7%.
基金supported by Ph.D.Programs Foundation of Ministry of Education of China,(No.20070019072)the Research Foundation of China Agricultural University(No.90020031).
文摘Highly efficient removal of allyloxycarbonyl （Alloc） group was achieved in the presence of CH3COONH4, Pd[P（C6H5）3]4, and NaBH4 in MeOH-THF, within 5 min in almost quantitative yields （〉90%, isolated yield） without affecting acetyl, benzoyl, isopropylidene, benzylidene, allyl, benzyl, benzyl carbonate, or azido groups.
基金Supported in part by the National Natural Science Foundation of China.
文摘The electronic structures of C_(60) ahd C_(60) M(M=Li,Na,K,Rb and Cs)were calculated by using an atom superposition and electron delocalization molecular orbital method.The results indicate that s valence electron of the atom of alkali metal was completely transferred to 5T_(1u) orbital of C_(60).The stabilization energy of the system results mainly from the electrostatic interaction between polarized C_(60) and alkali metal atom.
文摘Hydrogen peroxide (H2O2 ) concentrations were measured at two sites. One was on Lushan Mountain in May, 1987. The other was in Beijing in August, 1987 and in December, 1986. The automated fluorometric method was used for the determination of H2O2 . The concentrations of H2O2 ranged from approximately 0.50 to 4.32 ppb on Lushan Mountain. The concentrations of H2O2 ranged from approximately 0.05 to 1.49 ppb in August in Beijing, and it was only 0.01 ppb in December in Beijing.
基金Project supported by the National Natural Science Foundation of China and by NIH grant (to A. L. B.).
文摘Glycoconjugate, as a carrier of message, has important biological functions. The sugar moiety contains surprising information. Its molecular structure has been paid increasing attention to since the 1980’s. The application of softionization techniques, such as
文摘The primary conservation objective in China is to establish nature reserves to protect biological resources and natural heritage, protect ecosystems which are of global importance or have unique regional features, protect endangered and threatened species and their habitat, and safeguard the genetic resources. By 2000, the number of nature reserves increased to 1,276, while at the same time, the total area protected in nature reserves was up to 123 million ha. Of the total number of reserves, 908 sites ...
