Aim A reliable and rapid HPLC method was developed for quantitative determination of coniferyl femlate, an ester of ferulic acid, with multiple pharmacological activities in Angelica sinensis and Ligusticum chuanxiong...Aim A reliable and rapid HPLC method was developed for quantitative determination of coniferyl femlate, an ester of ferulic acid, with multiple pharmacological activities in Angelica sinensis and Ligusticum chuanxiong, two commonly used Chinese medicines. Methods The determination was achieved by using a Zorbax ODS C18 analytical column （250 mm×4.6 mm ID, 5 μm） at isocratic elution of 1% aqueous acetic acid and acetonitrile （1：1） with diode-array detection （318 nm）. The calibration curve of coniferyl femlate showed good linearity （r^2 = 0.9995） within the test range. Results The developed method showed good precision with intra- and inter-day variations of 0.22% - 1.16% and 0.86% - 2.62% between the levels of 0.380 - 0.038 mg·mL^-1, respectively. The repeatability represented as RSD of coniferyl femlate was less than 2.7% for three levels （0.2 - 1.0 g of Angelica sinensis）, and the recovery was 105.3% with RSD of 3.2%. Conclusion The validated method was successfully applied to quantify coniferyl femlate in 12 samples of Danggui and Chuanxiong.展开更多
Abstract： The Wenchuan earthquake generated strong surface disturbances and triggered a large number of loose deposits, resulting in the disaster- prone environment with special watershed hydrological characteristics...Abstract： The Wenchuan earthquake generated strong surface disturbances and triggered a large number of loose deposits, resulting in the disaster- prone environment with special watershed hydrological characteristics. This paper was to propose a debris flow formation process and explore the permeability characteristics and critical hydrodynamic conditions of the loose deposits triggered by the earthquake. The Guo Juanyan gully （31005＇27＂ N to 31005＇46＂ N, 103036＇58＂ E to 103037＇09＂ E） in Du Jiangyan City, located in the meizoseismal areas of the Wenchuan earthquake, was chosen as the study area and the disaster-prone environment was analyzed. The formation process of the debris flow was first proposed using a stability analysis, and then, the permeability characteristics of loose deposits were determined via in situ permeability experiments. Finally, the critical 1 h rainfall was simulated through a distributed hydrological model and verified by field observations. The formation process of debris flow could be divided into three stages based on the relationship between the hydrodynamic force and loose deposit resistance. The critical 1 h rainfall amounts under three antecedent moisture conditions （I-dry, Ⅱ-normal and Ⅲ-wet） were 52 mm/h, 43 mm/h and 34 mm/h, respectively. This study proposed a debris flow formation process in the meizoseismal areas of the Wenchuan earthquake based on the stability analysis and defined the rainfall threshold for debris flow early warning at the local level, which is significant for debris flow mitigation and risk management.展开更多
Over 240 debris flows occurred in hill-slopes, gullies （ indicated those with single-channel） and watersheds （indicated those with tributaries and channels） on July 10th 2013 in the Wenchuan county, and caused 29 ...Over 240 debris flows occurred in hill-slopes, gullies （ indicated those with single-channel） and watersheds （indicated those with tributaries and channels） on July 10th 2013 in the Wenchuan county, and caused 29 casualties and about 633×10^6 USD losses. This work aimed to analyze characteristics, hazards and causes of these events and explore mitigating measures based on field investigation and remote sensing images interpretation. The debris flows contained clay content of 0.1%~3.56%, having densities of 1.72-2.14 t/m^3, velocities of 5.0-m.7 m/s, discharges of 335-2353 m^3/s and sediment yields of 0.10-1.26×10^6 m^3, and also numerously occurred in large watersheds with the area over lo km^2. Large debris flows formed 3 hazard-chains in slopes, gullies, watersheds and rivers, which all evolved in dammed lakes and outburst flood, and 26 dammed lakes and lO newly ones were generated along the rivers of Min and Yuzi. The remarkable spatial difference of loose solid materials accumulation and intense rainfall, with the cumulative of about or more than 150 mm and the hourly of over 16mm, caused debris flows in the sections from Yingxiu to Miansi and Gengda. The damages on buildings, reconstructions, highways,factories and hydro power station originated from the impacting, scouring, burying of debris flows, the submerging of dammed lake and the scouring of outburst flood, and the huge losses came from the ruinous destructions of control engineering works of debris flows as well as the irrational location and low- resistant capabilities of reconstructions. For hazards mitigating of debris flows in long term, the feasible measures for short term, including risk-reassessing of foregone and potential hazard sites, regional alarming system establishing and integrated control in disastrous sites, and middle-long term, including improving reconstruction standard, rationally disposing river channel bed rise and selecting appropriate reconstruction time and plans, were strongly suggested.展开更多
This paper presents the changes of crust thickness and Poisson＇s ratios distribution in the Binchuan region, where the first air-gun transmitting station and it＇s a small dense array were deployed. From September 20...This paper presents the changes of crust thickness and Poisson＇s ratios distribution in the Binchuan region, where the first air-gun transmitting station and it＇s a small dense array were deployed. From September 2011 to January 2014, more than 239 teleseismic events of M≥ 6.0 were recorded in 16 stations in the Binchuan region. Their P-wave receiver functions were analyzed respectively. The high spatial resolution result shows that the average crust thickness of Binchuan region is 45.3km, it follows the rule of ＂deeper in the north and east part, shallower in the south and west part. ＂ The deepest region is in Xiaoyindian Station; the crust thickness is 47.9km; the shallowest region is in Paiying Station, it has the thickness of 42. lkm. It shows that the deeper Moho surface nearby the Chenghai fault and shallower nearby the Honghe fault; the isoline distribution of thickness changes greatly nearby the Chenghai fault and slowly nearby the Honghe fault. From the distribution of Poisson＇s ratios, it is unevenly in the study area with a great difference from the north part to the south part, which shows a characteristic of ＂lower in the north, higher in the south＂. The Poisson＇s ratio nearby the Honghe fault is medium too high （ 0. 26 ≤ σ≤0. 29 ） ; lower nearby the Chenghai fault （ ≤0. 26）. This paper concludes the possible reason of different characteristic between Poisson＇s ratio and crust thickness is thicker in the upper crust in the Binchuan region.展开更多
The Wenchuan earthquake caused numerous landslides and collapses that provide abundant unconsolidated material for future mobilization as debris flows.Debris flows will be very active and cause considerable damage for...The Wenchuan earthquake caused numerous landslides and collapses that provide abundant unconsolidated material for future mobilization as debris flows.Debris flows will be very active and cause considerable damage for some time in the affected area.Because of environmental changes related to the earthquake,many potentially dangerous debris flow gullies have yet to be identified.This paper selects the upper Min River from Yinxiu to Wenchuan as the study area,interprets the unconsolidated deposits,and discusses their relationship to distance from the fault.Then,applying that information and the values of other factors relating to debris flow occurrence,the locations of potential debris flows are analyzed by multi-factor comprehensive identification and rapid identification.The multi-factor comprehensive identification employs fuzzy matter-element extension theory.The volume of unconsolidated material in the study area is about 3.28 × 108 m3.According to the analysis by multi-factor comprehensive identification,47 gullies have a high probability for potential debris flow,8 gullies have a moderate probability,and 1 gully has a low probability.展开更多
基金Macao Science and Technology Development Fund(049/2005/A-R1) Jiangsu Key Laboratory for TCM FormulaeResearch, Nanjing University of Traditional Chinese Medicine (No.022021014003).
文摘Aim A reliable and rapid HPLC method was developed for quantitative determination of coniferyl femlate, an ester of ferulic acid, with multiple pharmacological activities in Angelica sinensis and Ligusticum chuanxiong, two commonly used Chinese medicines. Methods The determination was achieved by using a Zorbax ODS C18 analytical column （250 mm×4.6 mm ID, 5 μm） at isocratic elution of 1% aqueous acetic acid and acetonitrile （1：1） with diode-array detection （318 nm）. The calibration curve of coniferyl femlate showed good linearity （r^2 = 0.9995） within the test range. Results The developed method showed good precision with intra- and inter-day variations of 0.22% - 1.16% and 0.86% - 2.62% between the levels of 0.380 - 0.038 mg·mL^-1, respectively. The repeatability represented as RSD of coniferyl femlate was less than 2.7% for three levels （0.2 - 1.0 g of Angelica sinensis）, and the recovery was 105.3% with RSD of 3.2%. Conclusion The validated method was successfully applied to quantify coniferyl femlate in 12 samples of Danggui and Chuanxiong.
基金Financial support was provided by the international cooperation project of the Ministry of Science and Technology (Grant No.2013DFA21720)the Key Laboratory of Mountain Hazards and Earth Surface Processes independent project fundingthe National Natural Science Foundation (Grant No. 41372331)
文摘Abstract： The Wenchuan earthquake generated strong surface disturbances and triggered a large number of loose deposits, resulting in the disaster- prone environment with special watershed hydrological characteristics. This paper was to propose a debris flow formation process and explore the permeability characteristics and critical hydrodynamic conditions of the loose deposits triggered by the earthquake. The Guo Juanyan gully （31005＇27＂ N to 31005＇46＂ N, 103036＇58＂ E to 103037＇09＂ E） in Du Jiangyan City, located in the meizoseismal areas of the Wenchuan earthquake, was chosen as the study area and the disaster-prone environment was analyzed. The formation process of the debris flow was first proposed using a stability analysis, and then, the permeability characteristics of loose deposits were determined via in situ permeability experiments. Finally, the critical 1 h rainfall was simulated through a distributed hydrological model and verified by field observations. The formation process of debris flow could be divided into three stages based on the relationship between the hydrodynamic force and loose deposit resistance. The critical 1 h rainfall amounts under three antecedent moisture conditions （I-dry, Ⅱ-normal and Ⅲ-wet） were 52 mm/h, 43 mm/h and 34 mm/h, respectively. This study proposed a debris flow formation process in the meizoseismal areas of the Wenchuan earthquake based on the stability analysis and defined the rainfall threshold for debris flow early warning at the local level, which is significant for debris flow mitigation and risk management.
基金supported by the Key Program of National Natural Science Found of China (Grant No. 41030742)the Program of National Natural Science Found of China (Grant No. 41171012)
文摘Over 240 debris flows occurred in hill-slopes, gullies （ indicated those with single-channel） and watersheds （indicated those with tributaries and channels） on July 10th 2013 in the Wenchuan county, and caused 29 casualties and about 633×10^6 USD losses. This work aimed to analyze characteristics, hazards and causes of these events and explore mitigating measures based on field investigation and remote sensing images interpretation. The debris flows contained clay content of 0.1%~3.56%, having densities of 1.72-2.14 t/m^3, velocities of 5.0-m.7 m/s, discharges of 335-2353 m^3/s and sediment yields of 0.10-1.26×10^6 m^3, and also numerously occurred in large watersheds with the area over lo km^2. Large debris flows formed 3 hazard-chains in slopes, gullies, watersheds and rivers, which all evolved in dammed lakes and outburst flood, and 26 dammed lakes and lO newly ones were generated along the rivers of Min and Yuzi. The remarkable spatial difference of loose solid materials accumulation and intense rainfall, with the cumulative of about or more than 150 mm and the hourly of over 16mm, caused debris flows in the sections from Yingxiu to Miansi and Gengda. The damages on buildings, reconstructions, highways,factories and hydro power station originated from the impacting, scouring, burying of debris flows, the submerging of dammed lake and the scouring of outburst flood, and the huge losses came from the ruinous destructions of control engineering works of debris flows as well as the irrational location and low- resistant capabilities of reconstructions. For hazards mitigating of debris flows in long term, the feasible measures for short term, including risk-reassessing of foregone and potential hazard sites, regional alarming system establishing and integrated control in disastrous sites, and middle-long term, including improving reconstruction standard, rationally disposing river channel bed rise and selecting appropriate reconstruction time and plans, were strongly suggested.
基金sponsored by the Special Science and Technology Program of Earthquake Administration of Yunnan Province (KJZX02)Academician Chen Yong Workstation Project of Earthquake Administration of Yunnan Province
文摘This paper presents the changes of crust thickness and Poisson＇s ratios distribution in the Binchuan region, where the first air-gun transmitting station and it＇s a small dense array were deployed. From September 2011 to January 2014, more than 239 teleseismic events of M≥ 6.0 were recorded in 16 stations in the Binchuan region. Their P-wave receiver functions were analyzed respectively. The high spatial resolution result shows that the average crust thickness of Binchuan region is 45.3km, it follows the rule of ＂deeper in the north and east part, shallower in the south and west part. ＂ The deepest region is in Xiaoyindian Station; the crust thickness is 47.9km; the shallowest region is in Paiying Station, it has the thickness of 42. lkm. It shows that the deeper Moho surface nearby the Chenghai fault and shallower nearby the Honghe fault; the isoline distribution of thickness changes greatly nearby the Chenghai fault and slowly nearby the Honghe fault. From the distribution of Poisson＇s ratios, it is unevenly in the study area with a great difference from the north part to the south part, which shows a characteristic of ＂lower in the north, higher in the south＂. The Poisson＇s ratio nearby the Honghe fault is medium too high （ 0. 26 ≤ σ≤0. 29 ） ; lower nearby the Chenghai fault （ ≤0. 26）. This paper concludes the possible reason of different characteristic between Poisson＇s ratio and crust thickness is thicker in the upper crust in the Binchuan region.
基金supported by the 973 Program (2008CB425803)the Project group of the Knowledge Innovation Program (Kzcx2-Yw-Q03-5-2)National Natural Science Foundation of China (Grant No. 40901008)
文摘The Wenchuan earthquake caused numerous landslides and collapses that provide abundant unconsolidated material for future mobilization as debris flows.Debris flows will be very active and cause considerable damage for some time in the affected area.Because of environmental changes related to the earthquake,many potentially dangerous debris flow gullies have yet to be identified.This paper selects the upper Min River from Yinxiu to Wenchuan as the study area,interprets the unconsolidated deposits,and discusses their relationship to distance from the fault.Then,applying that information and the values of other factors relating to debris flow occurrence,the locations of potential debris flows are analyzed by multi-factor comprehensive identification and rapid identification.The multi-factor comprehensive identification employs fuzzy matter-element extension theory.The volume of unconsolidated material in the study area is about 3.28 × 108 m3.According to the analysis by multi-factor comprehensive identification,47 gullies have a high probability for potential debris flow,8 gullies have a moderate probability,and 1 gully has a low probability.
