Tight gas sandstone reservoirs in Guang＇an are characterized by wide distribution and low abundance. Sandstone samples from this area usually have low porosity and poor connectivity. We analyze the observed velocity ...Tight gas sandstone reservoirs in Guang＇an are characterized by wide distribution and low abundance. Sandstone samples from this area usually have low porosity and poor connectivity. We analyze the observed velocity data of tight sandstone samples with the Mori- Tanaka model, and give the sandstone framework physical model in this area based on theory and experiment analysis. The matrix modulus was obtained by an empirical relationship and then the experiment data were compared with the values predicted by the Mori-Tanaka model with different pore shapes. The results revealed that the experiment data were close to the model with low pore aspect ratio. Considering the matrix modulus and pore shape variation, we find that, under the condition of small mineral composition change, the effective pore aspect ratio of these samples increased with porosity evidently.展开更多
Objective To investigate the diagnosis and therapy of mediastinal enterogenous cysts in children. Methods Clinical data of 17 cases with mediastinal enterogenous cysts within 19 years in our hospital were retrospectiv...Objective To investigate the diagnosis and therapy of mediastinal enterogenous cysts in children. Methods Clinical data of 17 cases with mediastinal enterogenous cysts within 19 years in our hospital were retrospectively analyzed. Results One case was intramural esophageal cyst and 16 cases were enteric cysts, two among which were complicated with abdominal enteric duplications. Most cases presented with symptoms of respiratory distress. Twelve cases were complicated with vertebral anomalies. Ultrasound helpful in confirming the cystic nature of these lesions. posterior mediastinum. of 12 cases and magnetic resonance imaging of 4 cases were Eight cases had technetium-99m pertechnetate scintigraphy of posterior mediastinum.Conclusions Most patients present with symptoms of respiratory distress, complicated with vertebral anomalies. Ultrasonography and magnetic resonance imaging may be helpful in confirming the cystic nature of these lesions. Technetium-99m pertechnetate scintigraphy is the most effective method for differentiation of the disease from other mediastinal cysts.展开更多
In the past, blast-resistant designs for structures were often constructed with massive type structural systems, which relied more on brute strength than on finesse to achieve the required blast resistance. However, s...In the past, blast-resistant designs for structures were often constructed with massive type structural systems, which relied more on brute strength than on finesse to achieve the required blast resistance. However, structures composed of COLD-FORMED steel components, such as sheet metal and metal studs, have shown great promise in providing blast resistance with the added benefits of low cost and ease of construction. Some examples of using such structures to provide containment for package handling facilities (PHF) are described in the paper for situations where blast containment is needed, such as a potential package bomb being discovered during the package vetting process. Results from tests and analytic data are used to illustrate aspects of design peculiar to such types of applications. Designs for specific capacities of PHF are described.展开更多
基金supported by the National Natural Foundation of China (No. 41104066)the Basic Research Programs of CNPC during the 12th Five-Year Plan Period (No. 2011A-3601)+1 种基金the Major State Basic Research Development Program of China (No. 2007CB209505)RIPED Young Innovation Foundation (No. 2010-A-26-01)
文摘Tight gas sandstone reservoirs in Guang＇an are characterized by wide distribution and low abundance. Sandstone samples from this area usually have low porosity and poor connectivity. We analyze the observed velocity data of tight sandstone samples with the Mori- Tanaka model, and give the sandstone framework physical model in this area based on theory and experiment analysis. The matrix modulus was obtained by an empirical relationship and then the experiment data were compared with the values predicted by the Mori-Tanaka model with different pore shapes. The results revealed that the experiment data were close to the model with low pore aspect ratio. Considering the matrix modulus and pore shape variation, we find that, under the condition of small mineral composition change, the effective pore aspect ratio of these samples increased with porosity evidently.
文摘Objective To investigate the diagnosis and therapy of mediastinal enterogenous cysts in children. Methods Clinical data of 17 cases with mediastinal enterogenous cysts within 19 years in our hospital were retrospectively analyzed. Results One case was intramural esophageal cyst and 16 cases were enteric cysts, two among which were complicated with abdominal enteric duplications. Most cases presented with symptoms of respiratory distress. Twelve cases were complicated with vertebral anomalies. Ultrasound helpful in confirming the cystic nature of these lesions. posterior mediastinum. of 12 cases and magnetic resonance imaging of 4 cases were Eight cases had technetium-99m pertechnetate scintigraphy of posterior mediastinum.Conclusions Most patients present with symptoms of respiratory distress, complicated with vertebral anomalies. Ultrasonography and magnetic resonance imaging may be helpful in confirming the cystic nature of these lesions. Technetium-99m pertechnetate scintigraphy is the most effective method for differentiation of the disease from other mediastinal cysts.
文摘In the past, blast-resistant designs for structures were often constructed with massive type structural systems, which relied more on brute strength than on finesse to achieve the required blast resistance. However, structures composed of COLD-FORMED steel components, such as sheet metal and metal studs, have shown great promise in providing blast resistance with the added benefits of low cost and ease of construction. Some examples of using such structures to provide containment for package handling facilities (PHF) are described in the paper for situations where blast containment is needed, such as a potential package bomb being discovered during the package vetting process. Results from tests and analytic data are used to illustrate aspects of design peculiar to such types of applications. Designs for specific capacities of PHF are described.
