Thalictrum plants are perennial herbs in the family Ranuneulaceae, many of which are of important medicinal values. Alkaloids are major active constituents in Thalictrum plants in addition to a small amount of triterp...Thalictrum plants are perennial herbs in the family Ranuneulaceae, many of which are of important medicinal values. Alkaloids are major active constituents in Thalictrum plants in addition to a small amount of triterpene and flavonoids. The major pharmacological functions of the active constituents include： anti-tumor, anti- virus, antibiosis, antiphlogosis, hypotensive action, and etc. This paper summarizes the methods for determining the contents of chemical constituents in Thalictrum plants and new chemical constituents discovered in this genus in recent ten years.展开更多
Glaciers in the western Nyainqentanglha Range are an important source of water for social and economic development. Changes in their area were derived from two Chinese glacier inventories; one from the 197o 1：5o,ooo ...Glaciers in the western Nyainqentanglha Range are an important source of water for social and economic development. Changes in their area were derived from two Chinese glacier inventories; one from the 197o 1：5o,ooo scale Chinese Topographic Maps series and the other from Landsat TM/ETM＋ images acquired in 2009. Analyses also included boundaries from 2000 and 2014 Landsat TM/ETM＋ images. A continuing and accelerating shrinkage of glaciers occurred here from 1970 to 2014, with glacier area decreasing by 244.38±29.48 km^2 （27.4%±3.3%） or 0.62%±0.08% a^-1. While this is consistent with a changing climate, local topographic parameters, such as altitude, slope, aspect and debris cover, are also important influences. Recession is manifested by a rise in the elevation of the glacier terminus. The shrinkage of glaciers with NE, N and NW orientations exceeded that of other aspects, and glaciers with SE and S orientations experienced less shrinkage. Changes in the average positive difference of glaciation （PDG） show that the western Nyainqentanglha Range has unfavorable conditions for glacier maintenance which is being exacerbated by a warming climate since 1970.展开更多
In this paper,research of aftershock mechanisms is reviewed,including heterogeneity of medium and stress,mechanical loading,fluid intrusion and stress corrosion,and ratestate dependence.Previous studies have indicated...In this paper,research of aftershock mechanisms is reviewed,including heterogeneity of medium and stress,mechanical loading,fluid intrusion and stress corrosion,and ratestate dependence.Previous studies have indicated that the heterogeneity of media and stress is the basic premise of aftershocks generated.From the point view of mechanics,transient creep and afterslip can explain the decay of aftershocks in a short time after a mainshock and the relaxation of stress tends to interpret the characteristics of long-term aftershocks.Fluid intrusion and stress corrosion control the evolution process of the aftershocks under certain conditions.The interaction between the faults perturbed by the mainshock always exists during the aftershock activities.All kinds of models and the theories want to comply with the two basic power-law relationships---the G-R law and Omori law to some extent.展开更多
Understanding present patterns of genetic diversity is critical in order to design effective conservation and manage- ment strategies for endangered species. Tangjiahe Nature Reserve （NR） is one of the most importan...Understanding present patterns of genetic diversity is critical in order to design effective conservation and manage- ment strategies for endangered species. Tangjiahe Nature Reserve （NR） is one of the most important national reserves for giant pandas Ailuropoda melanoleuca in China. Previous studies have shown that giant pandas in Tangjiahe NR may be threatened by population decline and fragmentation. Here we used 10 microsatellite DNA markers to assess the genetic variability in the Tang- jiahe population. The results indicate a low level of genetic differentiation between the Hongshihe and Motianling subpopulations in the reserve. Assignment tests using the Bayesian clustering method in STRUCTURE identified one genetic cluster from 42 in- dividuals of the two subpopulations. All individuals from the same subpopulation were assigned to one cluster. This indicates high gene flow between subpopulations. F statistic analyses revealed a low Fzs-value of 0.024 in the total population and implies a randomly mating population in Tangjiahe NR. Additionally, our data show a high level of genetic diversity for the Tangjiahe population. Mean allele number （A）, Allelic richness （AR） and mean expected heterozygosity （HE） for the Tangjiahe population was 5.9, 5.173 and 0.703, respectively. This wild giant panda population can be restored through concerted effort展开更多
基金Supported by the State Key Development Program for Basic Research of ChinaScientific and Technological Development Project of Shandong Province(2008GG2NS02022)~~
文摘Thalictrum plants are perennial herbs in the family Ranuneulaceae, many of which are of important medicinal values. Alkaloids are major active constituents in Thalictrum plants in addition to a small amount of triterpene and flavonoids. The major pharmacological functions of the active constituents include： anti-tumor, anti- virus, antibiosis, antiphlogosis, hypotensive action, and etc. This paper summarizes the methods for determining the contents of chemical constituents in Thalictrum plants and new chemical constituents discovered in this genus in recent ten years.
基金supported by the fundamental program from the Ministry of Science and Technology of China(MOST)(Grant No.2013FY111400)the National Natural Science Foundation of China(Grant No.41190084)+1 种基金the MOST Technology Oriented Project(Grant No.2012BAC19B07)The second Chinese Glacier Inventory was a product of the previous MOST Project(Grant No.2006FY110200)
文摘Glaciers in the western Nyainqentanglha Range are an important source of water for social and economic development. Changes in their area were derived from two Chinese glacier inventories; one from the 197o 1：5o,ooo scale Chinese Topographic Maps series and the other from Landsat TM/ETM＋ images acquired in 2009. Analyses also included boundaries from 2000 and 2014 Landsat TM/ETM＋ images. A continuing and accelerating shrinkage of glaciers occurred here from 1970 to 2014, with glacier area decreasing by 244.38±29.48 km^2 （27.4%±3.3%） or 0.62%±0.08% a^-1. While this is consistent with a changing climate, local topographic parameters, such as altitude, slope, aspect and debris cover, are also important influences. Recession is manifested by a rise in the elevation of the glacier terminus. The shrinkage of glaciers with NE, N and NW orientations exceeded that of other aspects, and glaciers with SE and S orientations experienced less shrinkage. Changes in the average positive difference of glaciation （PDG） show that the western Nyainqentanglha Range has unfavorable conditions for glacier maintenance which is being exacerbated by a warming climate since 1970.
基金sponsored by the National Key Technology R&D Program of China(2012BAK19B0205)Key Foundation of Earthquake Administration of Shandong Province(JJ1308Y)
文摘In this paper,research of aftershock mechanisms is reviewed,including heterogeneity of medium and stress,mechanical loading,fluid intrusion and stress corrosion,and ratestate dependence.Previous studies have indicated that the heterogeneity of media and stress is the basic premise of aftershocks generated.From the point view of mechanics,transient creep and afterslip can explain the decay of aftershocks in a short time after a mainshock and the relaxation of stress tends to interpret the characteristics of long-term aftershocks.Fluid intrusion and stress corrosion control the evolution process of the aftershocks under certain conditions.The interaction between the faults perturbed by the mainshock always exists during the aftershock activities.All kinds of models and the theories want to comply with the two basic power-law relationships---the G-R law and Omori law to some extent.
文摘Understanding present patterns of genetic diversity is critical in order to design effective conservation and manage- ment strategies for endangered species. Tangjiahe Nature Reserve （NR） is one of the most important national reserves for giant pandas Ailuropoda melanoleuca in China. Previous studies have shown that giant pandas in Tangjiahe NR may be threatened by population decline and fragmentation. Here we used 10 microsatellite DNA markers to assess the genetic variability in the Tang- jiahe population. The results indicate a low level of genetic differentiation between the Hongshihe and Motianling subpopulations in the reserve. Assignment tests using the Bayesian clustering method in STRUCTURE identified one genetic cluster from 42 in- dividuals of the two subpopulations. All individuals from the same subpopulation were assigned to one cluster. This indicates high gene flow between subpopulations. F statistic analyses revealed a low Fzs-value of 0.024 in the total population and implies a randomly mating population in Tangjiahe NR. Additionally, our data show a high level of genetic diversity for the Tangjiahe population. Mean allele number （A）, Allelic richness （AR） and mean expected heterozygosity （HE） for the Tangjiahe population was 5.9, 5.173 and 0.703, respectively. This wild giant panda population can be restored through concerted effort
