Feiyan Shoal is a sub Yellow River Delta, which was formed from Jan. 1964 to May 1976, when the Yellow River entered sea via Diaokou Channel. Since the terminal reach shifted to Qingshuigou channel in 1976, Feiyan Sho...Feiyan Shoal is a sub Yellow River Delta, which was formed from Jan. 1964 to May 1976, when the Yellow River entered sea via Diaokou Channel. Since the terminal reach shifted to Qingshuigou channel in 1976, Feiyan Shoal has been experiencing severe erosion and retreat. This paper explains the evolutionary characteristics of the typical profile of Feiyan Shoal from the perspective of dynamical force and sediments＇ characteristics. All this is on the basis of the data of topographic profiles observed since the 1970s and the samples of hydrology and sediments collected in situ in Apr. 2004, the analysis of the retreating distance, and the tidal and wave friction velocity distribution. Feiyan Shoal topographical profile has experienced a course of ＂fast erosion and retrogression - slow eroding modulation - fluctuate triggering change＂ in recent 30 years, which is also the gradual disappearing process of the delta front. The different intensity of sediment erosion resistance is the main reason for the erosion speed changes. Due to the hydrodynamic force changes, the water depth range of maximum retreating distance and between erosion and progradation became shallow. It indicates that the storm tide will still be the triggering force of seashore topographic profile evolutions in the future.展开更多
Based on analysis of field survey, drilling and seismic data, the formation and evolution process of Deyang-Anyue erosion rift trough in Sichuan Basin was reconstructed, and exploration areas were divided and evaluate...Based on analysis of field survey, drilling and seismic data, the formation and evolution process of Deyang-Anyue erosion rift trough in Sichuan Basin was reconstructed, and exploration areas were divided and evaluated. The results show that:(1) Dengying Formation in and around Deyang-Anyue erosion rift trough varies widely in sedimentary characteristics. The Dengying Formation in the northern part of the erosion rift trough developed deep-water sediments, the Dengying Formation in the northern part of the basin varied gradually from basin to slope, platform margin, and restricted platform, and the Dengying Formation in the middle and southern parts of the trough developed carbonate platform facies.(2) Deyang-Anyue erosion rift trough is formed by extensional rift and karst erosion jointly, the north section of the erosion rift trough is mainly the product of tensile rift, while the middle and south sections are formed by erosion in multi-episodes of Tongwan period.(3) Based on the segmented origins of the erosion rift trough, Dengying Formation in and around it is divided into three exploration fields: lithologic mound and beach bodies at the northern platform margin of the basin, karst mound and beach bodies in the central platform, and karst residual mounds in the central southern trough of the basin, among them, the karst residual mounds in the central southern trough of the basin are a new frontier for natural gas exploration in the basin, and the lithologic mound and beach bodies at the northern platform margin are a new position for increasing the reserves of trillions of cubic meters of natural gas resources in the basin.展开更多
BACKGROUND Glenohumeral osteoarthritis(OA)is a common cause of pain and disability affecting nearly a third of the world’s population over 60 years of age.As in other joints,shoulder arthroplasty appears to be the mo...BACKGROUND Glenohumeral osteoarthritis(OA)is a common cause of pain and disability affecting nearly a third of the world’s population over 60 years of age.As in other joints,shoulder arthroplasty appears to be the most effective treatment.The implant design has evolved during time transitioning to shorter humeral stem lengths or even stemless components.AIM To evaluate the medium-term outcome and survival of a cementless humeral head resurfacing(HHR)in a group of patients affected with OA or avascular necrosis.METHODS This is a retrospective study of prospectively collected data using HHR in 23 patients(15 female and 8 male)after a 7.4 year follow-up.The collected data included clinical and radiographical evaluation.The Constant score,the visual analogue scale,and a clinical evaluation of range of motion were registered preand postoperatively.Fifteen patients affected with OA(2 cases of mild,6 moderate,and 7 severe)and 10 with avascular necrosis(stage III according to Cruess classification)were enrolled.X-rays were evaluated to detect loosening signs,degenerative changes,and superior humeral head migration.Magnetic resonance preoperatively was also performed to assess the rotator cuff status.Tendon integrity was mandatory to implant the HHR.RESULTS In total,19 patients(21 shoulders)completed the follow-up.Data on 4 shoulders,in 4 patients,were lost because of prosthesis failure.The global revision rate was 16%.A statistically significant improvement in the mean Constant score,visual analogue scale,and range of motion have been reported.No signs of loosening were registered,while in 12 cases a glenoid erosion was found.The osteophytes appeared 7 times on the humeral side and 12 on the glenoid.Superior humeral migration was recorded in only 1 case.CONCLUSION HHR remains a reasonable option in patients with an intact rotator cuff for the treatment of OA and avascular necrosis.展开更多
Gully erosion in the Paschim Medinipur district of West Bengal, Indiahas been an issue of anxiety, formed by the amputation of soil from narrow channels through the accretion of surface runoff. Here, we attempted to i...Gully erosion in the Paschim Medinipur district of West Bengal, Indiahas been an issue of anxiety, formed by the amputation of soil from narrow channels through the accretion of surface runoff. Here, we attempted to investigate the erosion variability of gully in a micro catchment area, and also scrutinized the gully cross-sectional areas as distinct components of gully volumes. Twelve gullies were randomly selected in different slopes. To determine the geometric growth of the gully dimensions and soil loss, the initial length of gully, the width of the gully and depth of respective gullies was monitored in different seasons. Univariate analysis was conducted to measure the association between gully head retreat and vegetation coverage, slope, rainfall volume and runoff contributing area. We found strong and significant relation between the slope of gully head and linear retreat in the pre monsoon (p 0.008) and post monsoon (p 0.024) season respectively. Conversely, rainfall volume and gully head retreat showed a strong relationship in the pre monsoon (r = 0.80), monsoon (r = 0.66) and post-monsoon period (r = 0.94);while meager relationship was observed with rainfall intensity (r = 0.06). Results also illustrated that the overall retreat of gully head had very strong and positive relationship with the runoff contributing area (r = 0.89, p 0.001), and maximum gully erosion was observed in the monsoon period (55.67%). These results indicate that slope, rainfall and runoff contributing area have a strong positive influence on gully erosion in Paschim Medinipur district, since the initiation of the gully.展开更多
-In this work, on the basis of the characteristics of coastal erosion near Xizhuang (Penglai, Shandong, China) and the in-situ measured data and theoretical calculation, the causes of coastal erosion there are obtaine...-In this work, on the basis of the characteristics of coastal erosion near Xizhuang (Penglai, Shandong, China) and the in-situ measured data and theoretical calculation, the causes of coastal erosion there are obtained: (1) natural erosion, (2) beach sand borrowing, and (3) sand borrowing at the Dengzhou shoal near Xizhuang, which results in the loss of the function of the wave force resistance of the shoal. Since the wave energy is increased, the longshore sediment transport rate is increased. Coastal erosions are more and more serious. A scientific basis to reduced the calamity of coastal erosion in local area is presented. Some experiences are accumulated for studying coastal erosion.展开更多
基金the Major State Basic Research Development Program of China(‘973’Program)(Grant No.2002CB412408)the Shanghai Youth Science and Technology Venus(GrantNo.06QA14016).
文摘Feiyan Shoal is a sub Yellow River Delta, which was formed from Jan. 1964 to May 1976, when the Yellow River entered sea via Diaokou Channel. Since the terminal reach shifted to Qingshuigou channel in 1976, Feiyan Shoal has been experiencing severe erosion and retreat. This paper explains the evolutionary characteristics of the typical profile of Feiyan Shoal from the perspective of dynamical force and sediments＇ characteristics. All this is on the basis of the data of topographic profiles observed since the 1970s and the samples of hydrology and sediments collected in situ in Apr. 2004, the analysis of the retreating distance, and the tidal and wave friction velocity distribution. Feiyan Shoal topographical profile has experienced a course of ＂fast erosion and retrogression - slow eroding modulation - fluctuate triggering change＂ in recent 30 years, which is also the gradual disappearing process of the delta front. The different intensity of sediment erosion resistance is the main reason for the erosion speed changes. Due to the hydrodynamic force changes, the water depth range of maximum retreating distance and between erosion and progradation became shallow. It indicates that the storm tide will still be the triggering force of seashore topographic profile evolutions in the future.
基金Supported by the National Key Research and Development Program of China (2017YFC0603106)Project of Science and Technology Department of PetroChina Southwest Oil and Gas Field Company (20200301-01)。
文摘Based on analysis of field survey, drilling and seismic data, the formation and evolution process of Deyang-Anyue erosion rift trough in Sichuan Basin was reconstructed, and exploration areas were divided and evaluated. The results show that:(1) Dengying Formation in and around Deyang-Anyue erosion rift trough varies widely in sedimentary characteristics. The Dengying Formation in the northern part of the erosion rift trough developed deep-water sediments, the Dengying Formation in the northern part of the basin varied gradually from basin to slope, platform margin, and restricted platform, and the Dengying Formation in the middle and southern parts of the trough developed carbonate platform facies.(2) Deyang-Anyue erosion rift trough is formed by extensional rift and karst erosion jointly, the north section of the erosion rift trough is mainly the product of tensile rift, while the middle and south sections are formed by erosion in multi-episodes of Tongwan period.(3) Based on the segmented origins of the erosion rift trough, Dengying Formation in and around it is divided into three exploration fields: lithologic mound and beach bodies at the northern platform margin of the basin, karst mound and beach bodies in the central platform, and karst residual mounds in the central southern trough of the basin, among them, the karst residual mounds in the central southern trough of the basin are a new frontier for natural gas exploration in the basin, and the lithologic mound and beach bodies at the northern platform margin are a new position for increasing the reserves of trillions of cubic meters of natural gas resources in the basin.
文摘BACKGROUND Glenohumeral osteoarthritis(OA)is a common cause of pain and disability affecting nearly a third of the world’s population over 60 years of age.As in other joints,shoulder arthroplasty appears to be the most effective treatment.The implant design has evolved during time transitioning to shorter humeral stem lengths or even stemless components.AIM To evaluate the medium-term outcome and survival of a cementless humeral head resurfacing(HHR)in a group of patients affected with OA or avascular necrosis.METHODS This is a retrospective study of prospectively collected data using HHR in 23 patients(15 female and 8 male)after a 7.4 year follow-up.The collected data included clinical and radiographical evaluation.The Constant score,the visual analogue scale,and a clinical evaluation of range of motion were registered preand postoperatively.Fifteen patients affected with OA(2 cases of mild,6 moderate,and 7 severe)and 10 with avascular necrosis(stage III according to Cruess classification)were enrolled.X-rays were evaluated to detect loosening signs,degenerative changes,and superior humeral head migration.Magnetic resonance preoperatively was also performed to assess the rotator cuff status.Tendon integrity was mandatory to implant the HHR.RESULTS In total,19 patients(21 shoulders)completed the follow-up.Data on 4 shoulders,in 4 patients,were lost because of prosthesis failure.The global revision rate was 16%.A statistically significant improvement in the mean Constant score,visual analogue scale,and range of motion have been reported.No signs of loosening were registered,while in 12 cases a glenoid erosion was found.The osteophytes appeared 7 times on the humeral side and 12 on the glenoid.Superior humeral migration was recorded in only 1 case.CONCLUSION HHR remains a reasonable option in patients with an intact rotator cuff for the treatment of OA and avascular necrosis.
文摘Gully erosion in the Paschim Medinipur district of West Bengal, Indiahas been an issue of anxiety, formed by the amputation of soil from narrow channels through the accretion of surface runoff. Here, we attempted to investigate the erosion variability of gully in a micro catchment area, and also scrutinized the gully cross-sectional areas as distinct components of gully volumes. Twelve gullies were randomly selected in different slopes. To determine the geometric growth of the gully dimensions and soil loss, the initial length of gully, the width of the gully and depth of respective gullies was monitored in different seasons. Univariate analysis was conducted to measure the association between gully head retreat and vegetation coverage, slope, rainfall volume and runoff contributing area. We found strong and significant relation between the slope of gully head and linear retreat in the pre monsoon (p 0.008) and post monsoon (p 0.024) season respectively. Conversely, rainfall volume and gully head retreat showed a strong relationship in the pre monsoon (r = 0.80), monsoon (r = 0.66) and post-monsoon period (r = 0.94);while meager relationship was observed with rainfall intensity (r = 0.06). Results also illustrated that the overall retreat of gully head had very strong and positive relationship with the runoff contributing area (r = 0.89, p 0.001), and maximum gully erosion was observed in the monsoon period (55.67%). These results indicate that slope, rainfall and runoff contributing area have a strong positive influence on gully erosion in Paschim Medinipur district, since the initiation of the gully.
文摘-In this work, on the basis of the characteristics of coastal erosion near Xizhuang (Penglai, Shandong, China) and the in-situ measured data and theoretical calculation, the causes of coastal erosion there are obtained: (1) natural erosion, (2) beach sand borrowing, and (3) sand borrowing at the Dengzhou shoal near Xizhuang, which results in the loss of the function of the wave force resistance of the shoal. Since the wave energy is increased, the longshore sediment transport rate is increased. Coastal erosions are more and more serious. A scientific basis to reduced the calamity of coastal erosion in local area is presented. Some experiences are accumulated for studying coastal erosion.
