A method based on the virtual prototype technology simulating the separation of a launch vehicle from its aircraft in the aircraft wake was proposed based on the internally carried air-launched launch vehicle program....A method based on the virtual prototype technology simulating the separation of a launch vehicle from its aircraft in the aircraft wake was proposed based on the internally carried air-launched launch vehicle program.In this method,the full-scale model of the aircraft,the vehicle and the parachute are constructed.Then,they are imported into the ADAMS software,constraint solutions and driving forces are then added for visual dynamic simulation.The unsteady aerodynamic forces of the vehicle in the aircraft wake are calculated by CFD and the moving grid technique.The forces generated by the parachute can be derived from the Kirchhoff motion equation.Through comparing and analyzing the simulation results under different launch conditions,it has been proven that this method simulates the separation of a launch vehicle from the aircraft in the aircraft wake accurately.It provides the foundation for the aggregate project of internally carried air-launch vehicles,and offers a new referenced method for multi-body dynamic simulation.展开更多
Neuroendocrine carcinoma(NEC) of the pancreas is rare.We report the case of a 34-year-old man with pancreatic NEC with soft tissue metastasis.The patient presented with right upper abdominal discomfort.Computed tomogr...Neuroendocrine carcinoma(NEC) of the pancreas is rare.We report the case of a 34-year-old man with pancreatic NEC with soft tissue metastasis.The patient presented with right upper abdominal discomfort.Computed tomography revealed a low-density heterogeneous mass in the tail and body of the pancreas that encroached on the greater curvature of the stomach and spleen.We performed exploratory laparotomy and total pancreatectomy with splenectomy and total gastrectomy.Histopathological analysis showed spindleshaped cells with scanty cytoplasm and hyperchromatic nuclei,confirming a primary pancreatic NEC.One month after the surgery,the patient experienced leg swelling.Positron emission tomography-computed tomography revealed high uptake of fludeoxyglucose in the left leg,and the leg was amputated.Histopathological analysis confirmed metastasis of pancreatic NEC.The patient was followed up and received chemotherapy(etoposide and cisplatin).One month after amputation,the level of tumor marker neuron-specific enolase was 142.70 μg/L and computed tomography scan revealed an aggravated metastatic lesion.The patient suffered from unbearable pain and we treated him with odynolysis.Four months postoperatively,the patient died of respiratory failure.展开更多
基金Supported by the National Natural Science Foundation Programme of China(No.61374145)
文摘A method based on the virtual prototype technology simulating the separation of a launch vehicle from its aircraft in the aircraft wake was proposed based on the internally carried air-launched launch vehicle program.In this method,the full-scale model of the aircraft,the vehicle and the parachute are constructed.Then,they are imported into the ADAMS software,constraint solutions and driving forces are then added for visual dynamic simulation.The unsteady aerodynamic forces of the vehicle in the aircraft wake are calculated by CFD and the moving grid technique.The forces generated by the parachute can be derived from the Kirchhoff motion equation.Through comparing and analyzing the simulation results under different launch conditions,it has been proven that this method simulates the separation of a launch vehicle from the aircraft in the aircraft wake accurately.It provides the foundation for the aggregate project of internally carried air-launch vehicles,and offers a new referenced method for multi-body dynamic simulation.
文摘Neuroendocrine carcinoma(NEC) of the pancreas is rare.We report the case of a 34-year-old man with pancreatic NEC with soft tissue metastasis.The patient presented with right upper abdominal discomfort.Computed tomography revealed a low-density heterogeneous mass in the tail and body of the pancreas that encroached on the greater curvature of the stomach and spleen.We performed exploratory laparotomy and total pancreatectomy with splenectomy and total gastrectomy.Histopathological analysis showed spindleshaped cells with scanty cytoplasm and hyperchromatic nuclei,confirming a primary pancreatic NEC.One month after the surgery,the patient experienced leg swelling.Positron emission tomography-computed tomography revealed high uptake of fludeoxyglucose in the left leg,and the leg was amputated.Histopathological analysis confirmed metastasis of pancreatic NEC.The patient was followed up and received chemotherapy(etoposide and cisplatin).One month after amputation,the level of tumor marker neuron-specific enolase was 142.70 μg/L and computed tomography scan revealed an aggravated metastatic lesion.The patient suffered from unbearable pain and we treated him with odynolysis.Four months postoperatively,the patient died of respiratory failure.
