A thin layer of yellow-brown-colored earth was generally found on Quaternary red clay in Jiujiang,Jiangxi Province. A typical profile was established. Both particle size distribution and REE (rare earthelements) chara...A thin layer of yellow-brown-colored earth was generally found on Quaternary red clay in Jiujiang,Jiangxi Province. A typical profile was established. Both particle size distribution and REE (rare earthelements) characteristics of the yellow-brown-colored earth of the profile fully suggested its aeolian origin andclose similarity to Naming Xiashu loess. The study also implied aeolian origin of the underlying Quaternaryred clap Compared with the red clay, the yellow- brown- colored earth was less weathered because of its lowercontent of free iron and higher mole ratios of SiO2/A12O3 and SiO2/(Fe2O3+A12O3 ) as well as its lessdeveloped chemical microtextures of quartz grains.In order to study the aged of the two deposits comparatively, the thermoluminescent dating method wasused. As a result, the bottom of the yellow-brown-colored esrth was dated to 6015 ka B. P. and the upperpart of the red clay 38854 ka B. P. It was suggested that the yellow- browm- colored earth was formed inthe Late Pleistocene and was probably the aeolian deposit of the Last Glacial, which corresponded with theMalan loess in the Loess Plateau of the northwestern part of China; while the underlying red clay was formedin the Middle Pleistocene.A "yellow cap" on Quaternary red clay in Jiujiang implied a great climatic and environmental varistionin the beginning of the Late Pleistocene in the southern pot of China, especially in the middle and lowerreaches of the Yangtze River. The eveal not only halted the rubification, once dominating the region, butalso produced a widespread covering of aeolian deposit, as only occurred in the cold and dry environment.展开更多
Murraya exotica L. is one of the two official source species of traditional Chinese medicine Murrayae Folium et Cacumen. At present, a rapid HPLC analysis method to simultaneously determine two major coumarins, hainan...Murraya exotica L. is one of the two official source species of traditional Chinese medicine Murrayae Folium et Cacumen. At present, a rapid HPLC analysis method to simultaneously determine two major coumarins, hainanmurpanin （1） and meranzin （2）, and one main flavonoid, 3,5,6,7,3＇,4＇,5＇-heptamethoxyflavone （3）, from the leaves and twigs of M. exotica was established. The analysis was performed on a DIKMA Spursil C18 column （4.6 minx250 mm, 5 ~m） at a flow rate of 1 mL/min, using acetonitrile-H20 （5：5, v/v） as mobile phase. The column temperature was 25 ^（2, and the detected wavelength was at 320 nm. The three analytes （1-3） were separated well with good linearity, precision, stability and repeatability. The average recoveries were in the range of 100.52%-101.97%, with RSD less than 1.73%. Twenty batches of M. exotica from different habitats were detected, and the sum of the contents of 1-3 was in the range of 1.55-7.45 mg/g, respectively. Besides, the contents of these three analytes were also determined for the samples from different medicinal parts （stems, lateral branches, mixture of twigs and leaves） and different harvest times. The results showed that the contents of these three analytes in leaves and twigs are much higher than those in the stems or lateral branches; the plants harvested from June or October contain more active compounds than those from the other months. The above results proved that this high performance and simple HPLC assay can be readily utilized as a practical method for the quality control of M. exotica.展开更多
文摘A thin layer of yellow-brown-colored earth was generally found on Quaternary red clay in Jiujiang,Jiangxi Province. A typical profile was established. Both particle size distribution and REE (rare earthelements) characteristics of the yellow-brown-colored earth of the profile fully suggested its aeolian origin andclose similarity to Naming Xiashu loess. The study also implied aeolian origin of the underlying Quaternaryred clap Compared with the red clay, the yellow- brown- colored earth was less weathered because of its lowercontent of free iron and higher mole ratios of SiO2/A12O3 and SiO2/(Fe2O3+A12O3 ) as well as its lessdeveloped chemical microtextures of quartz grains.In order to study the aged of the two deposits comparatively, the thermoluminescent dating method wasused. As a result, the bottom of the yellow-brown-colored esrth was dated to 6015 ka B. P. and the upperpart of the red clay 38854 ka B. P. It was suggested that the yellow- browm- colored earth was formed inthe Late Pleistocene and was probably the aeolian deposit of the Last Glacial, which corresponded with theMalan loess in the Loess Plateau of the northwestern part of China; while the underlying red clay was formedin the Middle Pleistocene.A "yellow cap" on Quaternary red clay in Jiujiang implied a great climatic and environmental varistionin the beginning of the Late Pleistocene in the southern pot of China, especially in the middle and lowerreaches of the Yangtze River. The eveal not only halted the rubification, once dominating the region, butalso produced a widespread covering of aeolian deposit, as only occurred in the cold and dry environment.
基金National Natural Science Foundation of China(Grant No.81222051 and 81473106)National Key Technology R&D Program"New Drug Innovation"of China(Grant No.2012ZX09301002-002-002 and 2012ZX09304-005)
文摘Murraya exotica L. is one of the two official source species of traditional Chinese medicine Murrayae Folium et Cacumen. At present, a rapid HPLC analysis method to simultaneously determine two major coumarins, hainanmurpanin （1） and meranzin （2）, and one main flavonoid, 3,5,6,7,3＇,4＇,5＇-heptamethoxyflavone （3）, from the leaves and twigs of M. exotica was established. The analysis was performed on a DIKMA Spursil C18 column （4.6 minx250 mm, 5 ~m） at a flow rate of 1 mL/min, using acetonitrile-H20 （5：5, v/v） as mobile phase. The column temperature was 25 ^（2, and the detected wavelength was at 320 nm. The three analytes （1-3） were separated well with good linearity, precision, stability and repeatability. The average recoveries were in the range of 100.52%-101.97%, with RSD less than 1.73%. Twenty batches of M. exotica from different habitats were detected, and the sum of the contents of 1-3 was in the range of 1.55-7.45 mg/g, respectively. Besides, the contents of these three analytes were also determined for the samples from different medicinal parts （stems, lateral branches, mixture of twigs and leaves） and different harvest times. The results showed that the contents of these three analytes in leaves and twigs are much higher than those in the stems or lateral branches; the plants harvested from June or October contain more active compounds than those from the other months. The above results proved that this high performance and simple HPLC assay can be readily utilized as a practical method for the quality control of M. exotica.
