For recent years,runoff generation and hydrological processes in Hailiutu River basin have been greatly changed by climate change and human activity,especially water and soil conservation construction.In this study,th...For recent years,runoff generation and hydrological processes in Hailiutu River basin have been greatly changed by climate change and human activity,especially water and soil conservation construction.In this study,the trends in precipitation,evapotranspiration(ET)and river runoff as well as the effects of precipitation change and human activity on runoff variation have been studied.The results showed that during 1960-2000,annual precipitation and river runoff,monthly precipitation and ET in September and October as well as monthly runoff in all months showed a significant decrease.In addition,peak flow and base flow had a large decrease.Under the joint influence of precipitation change and human activity,the mean annual runoff decreased by 35 million m3 from the baseline period(1960-1985)to the change period(1986-2000),which accounted for 60.9%and 39.1%of the total runoff decrease,respectively.Precipitation change played a primary role in the decrease of annual runoff whereas human activity,particularly water and soil conservation construction,also had remarkable impacts on runoff variation.展开更多
Abstract The phase behavior of twelve synthesized β- sitosteryl fatty acid esters with acyl moieties with different chain lengths （C2：0-C18：0） and different degrees of unsaturation （C18：1-C18：3） were investig...Abstract The phase behavior of twelve synthesized β- sitosteryl fatty acid esters with acyl moieties with different chain lengths （C2：0-C18：0） and different degrees of unsaturation （C18：1-C18：3） were investigated in pure and mixed Langmuir monolayers with phospholipids. The surface-pressure isotherms showed that short chain fl- sitosteryl fatty acid esters gave smaller mean molecular areas and had decreased monolayer stability and the long chain steryl esters did not produce collapsed plateaus. All the steryl esters displayed strong condensing effects, but there was a pronounced structural dependency： medium chain esters （C8 and C 10） were less efficient than short and long chain esters. Atomic force microscopy imaging demonstrated that monolayers mixed with dipalmitoyl phosphatidylcholine （DPPC） displayed both DPPC-rich and steryl lipid-rich domains. However, the height and area differences between the two phases and the roughness and morphologic patterns were very dependent on the steryl lipid concentrations as well as the length, the degree of unsaturation and the molecular conformations of the acyl segments. These findings not only provide a better understanding of the interactions between phytosteryl hydrophobic derivatives and biomembranes, but also may be of general use for the design and engineering of phytosterol structural derivations for specific food and pharmaceutical applications.展开更多
In order to develop novel antitumor d rugs,1,5-bis(2-hydroxybenzylidene)-thiocarbohydrazide(HL)and its Ag ?Complex([Ag2L]·NO3)have been prepared and characterize d by elemental analysis,IR,UV,1 H NMR and molar co...In order to develop novel antitumor d rugs,1,5-bis(2-hydroxybenzylidene)-thiocarbohydrazide(HL)and its Ag ?Complex([Ag2L]·NO3)have been prepared and characterize d by elemental analysis,IR,UV,1 H NMR and molar conductance,respectively.The inhibitory effects of them on five tumor cell lines,including HL-60,Bel-7402,EJ,HCT-8and A431 have been measured by using MTT(Dimethoxyneotetrazolium)colorimetric assay and SRB(Sulforhodamine B)assay.The result indicated that the Ag Complex has str onger inhibitory effect on the five t umor cell lines than the ligand,especially showed very stro ng effect on HL-60cell and Bel-7402c ell.When the exposure concentration of the complex was 10-5mol·L-1,The inhibitory rate is over 96%.展开更多
基金financially supported by National Natural Science Foundation of China[grant number 50239050],[grantnumber 40571029],[grant number 40901028]
文摘For recent years,runoff generation and hydrological processes in Hailiutu River basin have been greatly changed by climate change and human activity,especially water and soil conservation construction.In this study,the trends in precipitation,evapotranspiration(ET)and river runoff as well as the effects of precipitation change and human activity on runoff variation have been studied.The results showed that during 1960-2000,annual precipitation and river runoff,monthly precipitation and ET in September and October as well as monthly runoff in all months showed a significant decrease.In addition,peak flow and base flow had a large decrease.Under the joint influence of precipitation change and human activity,the mean annual runoff decreased by 35 million m3 from the baseline period(1960-1985)to the change period(1986-2000),which accounted for 60.9%and 39.1%of the total runoff decrease,respectively.Precipitation change played a primary role in the decrease of annual runoff whereas human activity,particularly water and soil conservation construction,also had remarkable impacts on runoff variation.
文摘Abstract The phase behavior of twelve synthesized β- sitosteryl fatty acid esters with acyl moieties with different chain lengths （C2：0-C18：0） and different degrees of unsaturation （C18：1-C18：3） were investigated in pure and mixed Langmuir monolayers with phospholipids. The surface-pressure isotherms showed that short chain fl- sitosteryl fatty acid esters gave smaller mean molecular areas and had decreased monolayer stability and the long chain steryl esters did not produce collapsed plateaus. All the steryl esters displayed strong condensing effects, but there was a pronounced structural dependency： medium chain esters （C8 and C 10） were less efficient than short and long chain esters. Atomic force microscopy imaging demonstrated that monolayers mixed with dipalmitoyl phosphatidylcholine （DPPC） displayed both DPPC-rich and steryl lipid-rich domains. However, the height and area differences between the two phases and the roughness and morphologic patterns were very dependent on the steryl lipid concentrations as well as the length, the degree of unsaturation and the molecular conformations of the acyl segments. These findings not only provide a better understanding of the interactions between phytosteryl hydrophobic derivatives and biomembranes, but also may be of general use for the design and engineering of phytosterol structural derivations for specific food and pharmaceutical applications.
文摘In order to develop novel antitumor d rugs,1,5-bis(2-hydroxybenzylidene)-thiocarbohydrazide(HL)and its Ag ?Complex([Ag2L]·NO3)have been prepared and characterize d by elemental analysis,IR,UV,1 H NMR and molar conductance,respectively.The inhibitory effects of them on five tumor cell lines,including HL-60,Bel-7402,EJ,HCT-8and A431 have been measured by using MTT(Dimethoxyneotetrazolium)colorimetric assay and SRB(Sulforhodamine B)assay.The result indicated that the Ag Complex has str onger inhibitory effect on the five t umor cell lines than the ligand,especially showed very stro ng effect on HL-60cell and Bel-7402c ell.When the exposure concentration of the complex was 10-5mol·L-1,The inhibitory rate is over 96%.
