Useful structure characteristics of elastic cylindrical shells have led them to being widely applied in virtual projects,so it is important to conduct vibration research on the shells and find it’s a simpler correspo...Useful structure characteristics of elastic cylindrical shells have led them to being widely applied in virtual projects,so it is important to conduct vibration research on the shells and find it’s a simpler corresponding compact calculation method. Utilising the input and transfer point mobility of a thin plate structure, a theoretical expression of the cylindrical shell’s bending vibration responsewas deduced and numerical simulations were done to simplify the theoretical expression within an acceptable error margin, greatly reducing the amount of computations. Furthermore, whole vibration response distributions of the cylindrical shell were analyzed. It was found thathe vibration energy propagates in helical form under mono-frequency excitation, while under bandwidth frequency excitation, it attenuates around in term of fluctuation.The axial attenuation rate of the vibration energy is larger than the circumferential attenuation rate.展开更多
The characteristics of seismogenic structures are an important basis for delineating the potential seismic source areas and determining the annual occurrence rate of earthquakes. The potential seismic source area does...The characteristics of seismogenic structures are an important basis for delineating the potential seismic source areas and determining the annual occurrence rate of earthquakes. The potential seismic source area does not only have the intension that “this area has the possibility for destructive earthquakes to occur in the future" but also means that earthquakes of high magnitude interval have the characteristics of similar recurrence. When determining the seismic activity parameters of a statistical unit, some active tectonic blocks in the unit may have different background earthquakes. In order to better reflect the heterogeneity in space of seismic activities, it is necessary to divide the potential seismic source areas into three orders. By analyzing the recurrence characteristics of earthquakes of high magnitude interval in the potential source area and calculating the occurrence probability of earthquakes of high magnitude interval in the potential seismic source area in the time window for prediction, the average annual occurrence rate of earthquakes can be obtained by the method of probability equivalent conversion in the time window for prediction. This would be helpful for considering the recurrence characteristics of strong earthquakes in potential source areas within the framework of seismic risk analysis of China. Besides, the insufficient frequency of characteristic earthquakes of the next high magnitude interval in the potential source area and the heterogeneity of strong earthquakes on seismogenic structures are analyzed to see their application in seismic risk analysis.展开更多
The Funan-Huoqiu area is located in the border tectonic belt between the North China and South China active block regions. By means of seismological and geological surveys and synthetic analysis, evidences of tectonic...The Funan-Huoqiu area is located in the border tectonic belt between the North China and South China active block regions. By means of seismological and geological surveys and synthetic analysis, evidences of tectonic deformation in lower intensity have been found in the area since Late Pleistocene, where small earthquakes are distributed linearly along the main faults, conjugate shear joints are developed in the Upper Pleistocene nearby the faults. In the south of the studied region, fissures with different lengths, widths and directions occurred successively in Gushi, Huoqiu, Funan and other places of the area, in the 1970’s, and the direction of the fissures is approximately consistent with that of the Feizhong fault and Wanglaorenji fault. The authors hold that the clustering of small earthquakes, the conjugate shear joints developed in the Upper Pleistocene, the crumpled deformation of materials on fault plane, and the development of modern surface fissures in the area all reflect that the energy in the crust was slowly released, and that the weak deformation took place in corresponding faults. There was only one destructive earthquake taking place in the area (the Jiangkouji {M_S43/4} earthquake). Altogather, there has been weak activity in the area since the Late Quaternary, and it is mainly shown as a creep-slip.展开更多
AIM To investigate the behavior of pulsatile pressure zones(PPZ's) as noted on high resolution esophageal impedance manometry(HREIM), and determine their association with dysphagia.METHODS Retrospective, single ce...AIM To investigate the behavior of pulsatile pressure zones(PPZ's) as noted on high resolution esophageal impedance manometry(HREIM), and determine their association with dysphagia.METHODS Retrospective, single center case control design scr-eening HREIM studies for cases(dysphagia) and controls(no dysphagia). Thoracic radiology studies were reviewed further in cases for(thoracic cardiovascular) thoracic cardiovascular(TCV) structures in esophageal proximity to compare with HREIM findings. Manometric data was collected for number, location, axial length, PPZ pressure and esophageal clearance function(impedance). RESULTS Among 317 screened patients, 56% cases and 64% controls had PPZ's. Fifty cases had an available thoracic radiology comparison. The distribution of PPZ's in these 50 cases and 59 controls was similar(average 1.4 PPZ/patient). Controls(mean 31.2 ± SD 12 years) were a significantly younger population than cases(mean 67.3 ± SD 14.9 years) with P < 0.0001. The upright posture PPZ pressure was higher in controls(15.7 ± 10.0 mm Hg) than cases(10.8 ± 9.7 mm Hg). Although statistically significant(P = 0.005), it was a weak predictor using logistic regression and ROC model(AUC = 0.65). Three dysphagia patients had partial compression from external TCV on radiology(1 aberrant subclavian artery, 2 dilated left atrium). The posture(supine vs upright) with more prominent PPZ's impaired bolus clearance in 9 additional cases by > 20%. CONCLUSION Transmitted TCV pulsations observed in HREIM bear no significant impact on swallowing. However, in older adults with dysphagia, evidence of impaired bolus clearance on impedance should be evaluated for external TCV compression. These associations have never been explored previously in literature, and are novel.展开更多
Animal habitat-use patterns cannot be isolated from scale issues. Consequently, multi-scale studies provide a complete characterization of ecological patterns that can further explain the observed variation. Liolaemus...Animal habitat-use patterns cannot be isolated from scale issues. Consequently, multi-scale studies provide a complete characterization of ecological patterns that can further explain the observed variation. Liolaemus constitutes the world＇s second most speciose lizard genus. In this study, we assessed the relationships between home range size and environmental variables at 3 different spatial scales. The study at a local and regional scale was focused on the habitat specialist Liolaemus multimaculatus. The lizard＇s home range was calculated using the minimum convex polygon method in populations from grassland sites of the coastal sand dunes of the Argentinean Pampas under 2 different conditions, with or without forestations of Acacia Iongifolia. On the other hand, at a geographical scale we considered the evolutionary implications of 20 species of Liolaemus. Home range size, phylogeny, ecological, environmental, and climatic data were ob- tained from the literature and remote sensing. L. multimaculatus home range varied from 12.66 to 570.00 m. Regionally, this species had smaller home ranges in forested habitats （X： 94.02 m2） com- pared with the non-forested sites （X： 219.78m2）. Habitat structure, vegetation types, and food availability would explain the space use at finer scales. When the 20 species of Liolaernus were considered, high mean air temperature and broad thermal amplitudes showed an inverse relationship with home range size. Neither net primary productivity nor phylogeny was good predictors for home range variation at geographical scale. This study highlights the scale dependence of the explicative capability of a set of environmental and intrinsic variables on home range patterns.展开更多
文摘Useful structure characteristics of elastic cylindrical shells have led them to being widely applied in virtual projects,so it is important to conduct vibration research on the shells and find it’s a simpler corresponding compact calculation method. Utilising the input and transfer point mobility of a thin plate structure, a theoretical expression of the cylindrical shell’s bending vibration responsewas deduced and numerical simulations were done to simplify the theoretical expression within an acceptable error margin, greatly reducing the amount of computations. Furthermore, whole vibration response distributions of the cylindrical shell were analyzed. It was found thathe vibration energy propagates in helical form under mono-frequency excitation, while under bandwidth frequency excitation, it attenuates around in term of fluctuation.The axial attenuation rate of the vibration energy is larger than the circumferential attenuation rate.
文摘The characteristics of seismogenic structures are an important basis for delineating the potential seismic source areas and determining the annual occurrence rate of earthquakes. The potential seismic source area does not only have the intension that “this area has the possibility for destructive earthquakes to occur in the future" but also means that earthquakes of high magnitude interval have the characteristics of similar recurrence. When determining the seismic activity parameters of a statistical unit, some active tectonic blocks in the unit may have different background earthquakes. In order to better reflect the heterogeneity in space of seismic activities, it is necessary to divide the potential seismic source areas into three orders. By analyzing the recurrence characteristics of earthquakes of high magnitude interval in the potential source area and calculating the occurrence probability of earthquakes of high magnitude interval in the potential seismic source area in the time window for prediction, the average annual occurrence rate of earthquakes can be obtained by the method of probability equivalent conversion in the time window for prediction. This would be helpful for considering the recurrence characteristics of strong earthquakes in potential source areas within the framework of seismic risk analysis of China. Besides, the insufficient frequency of characteristic earthquakes of the next high magnitude interval in the potential source area and the heterogeneity of strong earthquakes on seismogenic structures are analyzed to see their application in seismic risk analysis.
文摘The Funan-Huoqiu area is located in the border tectonic belt between the North China and South China active block regions. By means of seismological and geological surveys and synthetic analysis, evidences of tectonic deformation in lower intensity have been found in the area since Late Pleistocene, where small earthquakes are distributed linearly along the main faults, conjugate shear joints are developed in the Upper Pleistocene nearby the faults. In the south of the studied region, fissures with different lengths, widths and directions occurred successively in Gushi, Huoqiu, Funan and other places of the area, in the 1970’s, and the direction of the fissures is approximately consistent with that of the Feizhong fault and Wanglaorenji fault. The authors hold that the clustering of small earthquakes, the conjugate shear joints developed in the Upper Pleistocene, the crumpled deformation of materials on fault plane, and the development of modern surface fissures in the area all reflect that the energy in the crust was slowly released, and that the weak deformation took place in corresponding faults. There was only one destructive earthquake taking place in the area (the Jiangkouji {M_S43/4} earthquake). Altogather, there has been weak activity in the area since the Late Quaternary, and it is mainly shown as a creep-slip.
文摘AIM To investigate the behavior of pulsatile pressure zones(PPZ's) as noted on high resolution esophageal impedance manometry(HREIM), and determine their association with dysphagia.METHODS Retrospective, single center case control design scr-eening HREIM studies for cases(dysphagia) and controls(no dysphagia). Thoracic radiology studies were reviewed further in cases for(thoracic cardiovascular) thoracic cardiovascular(TCV) structures in esophageal proximity to compare with HREIM findings. Manometric data was collected for number, location, axial length, PPZ pressure and esophageal clearance function(impedance). RESULTS Among 317 screened patients, 56% cases and 64% controls had PPZ's. Fifty cases had an available thoracic radiology comparison. The distribution of PPZ's in these 50 cases and 59 controls was similar(average 1.4 PPZ/patient). Controls(mean 31.2 ± SD 12 years) were a significantly younger population than cases(mean 67.3 ± SD 14.9 years) with P < 0.0001. The upright posture PPZ pressure was higher in controls(15.7 ± 10.0 mm Hg) than cases(10.8 ± 9.7 mm Hg). Although statistically significant(P = 0.005), it was a weak predictor using logistic regression and ROC model(AUC = 0.65). Three dysphagia patients had partial compression from external TCV on radiology(1 aberrant subclavian artery, 2 dilated left atrium). The posture(supine vs upright) with more prominent PPZ's impaired bolus clearance in 9 additional cases by > 20%. CONCLUSION Transmitted TCV pulsations observed in HREIM bear no significant impact on swallowing. However, in older adults with dysphagia, evidence of impaired bolus clearance on impedance should be evaluated for external TCV compression. These associations have never been explored previously in literature, and are novel.
文摘Animal habitat-use patterns cannot be isolated from scale issues. Consequently, multi-scale studies provide a complete characterization of ecological patterns that can further explain the observed variation. Liolaemus constitutes the world＇s second most speciose lizard genus. In this study, we assessed the relationships between home range size and environmental variables at 3 different spatial scales. The study at a local and regional scale was focused on the habitat specialist Liolaemus multimaculatus. The lizard＇s home range was calculated using the minimum convex polygon method in populations from grassland sites of the coastal sand dunes of the Argentinean Pampas under 2 different conditions, with or without forestations of Acacia Iongifolia. On the other hand, at a geographical scale we considered the evolutionary implications of 20 species of Liolaemus. Home range size, phylogeny, ecological, environmental, and climatic data were ob- tained from the literature and remote sensing. L. multimaculatus home range varied from 12.66 to 570.00 m. Regionally, this species had smaller home ranges in forested habitats （X： 94.02 m2） com- pared with the non-forested sites （X： 219.78m2）. Habitat structure, vegetation types, and food availability would explain the space use at finer scales. When the 20 species of Liolaernus were considered, high mean air temperature and broad thermal amplitudes showed an inverse relationship with home range size. Neither net primary productivity nor phylogeny was good predictors for home range variation at geographical scale. This study highlights the scale dependence of the explicative capability of a set of environmental and intrinsic variables on home range patterns.
