A limited-area primitive equation model is used to study the role of the β-effect and a uniform current on tropical cyclone (TC) intensity. It is found that TC intensity is reduced in a non-quiescent environment comp...A limited-area primitive equation model is used to study the role of the β-effect and a uniform current on tropical cyclone (TC) intensity. It is found that TC intensity is reduced in a non-quiescent environment compared with the case of no uniform current. On an f-plane, the rate of intensification of a tropical cyclone is larger than that of the uniform flow. A TC on a β-plane intensifies slower than one on an f-plane. The main physical characteristic that distinguishes the experiments is the asymmetric thermodynamic (including convective) and dynamic structures present when either a uniform flow or β-effect is introduced. But a fairly symmetric TC structure is simulated on an f-plane. The magnitude of the warm core and the associated subsidence are found to be responsible for such simulated intensity changes. On an f-plane, the convection tends to be symmetric, which results in strong upper-level convergence near the center and hence strong forced subsidence and a very warm core. On the other hand, horizontal advection of temperature cancels part of the adiabatic heating and results in less warming of the core, and hence the TC is not as intense. This advective process is due to the tilt of the vortex as a result of the β-effect. A similar situation occurs in the presence of a uniform flow. Thus, the asymmetric horizontal advection of temperature plays an important role in the temperature distribution. Dynamically, the asymmetric angular momentum (AM) flux is very small on an f-plane throughout the troposphere. However, the total AM exports at the upper levels for a TC either on a β-plane or with a uniform flow environment are larger because of an increase of the asymmetric as well as symmetric AM export on the plane at radii >450 km, and hence there is a lesser intensification.展开更多
A 62-year-old woman was admitted to our hospital in2011 because of recurrent abdominal pain,nausea and constipation for six months.Computed tomography enterography(CTE)showed tortuous thread-like calcifications in the...A 62-year-old woman was admitted to our hospital in2011 because of recurrent abdominal pain,nausea and constipation for six months.Computed tomography enterography(CTE)showed tortuous thread-like calcifications in the ileocolic vein and right colic vein,while colonoscopy revealed purple-blue mucosa extending from the cecum to the splenic flexure.Based on the results of these tests,the patient was diagnosed with idiopathic mesenteric phlebosclerosis(IMP).She had a history of Chinese medical liquor intake for one and a half years and her symptoms subsided after conservative treatment.In 2013,a 63-year-old male patient who presented with recurrent lower right abdominal pain,bloating,melena and diarrhea for fifteen months was admitted to our institution.Colonoscopy and CTE led to the diagnosis of IMP.He also used Chinese medical liquor for approximately 12 years.The patient underwent total colectomy and the postoperative course was uneventful.We searched for previously published reports on similar cases and analyzed the clinical data of 50 cases identified in PubMed.As some of these patients admitted use of Chinese medicines,we hypothesize that Chinese medicines may play a role in the pathogenesis of IMP.展开更多
基金sponsored by the National Natural Science Foundation of China under Grant Nos.49975014,40275018,and 40333025
文摘A limited-area primitive equation model is used to study the role of the β-effect and a uniform current on tropical cyclone (TC) intensity. It is found that TC intensity is reduced in a non-quiescent environment compared with the case of no uniform current. On an f-plane, the rate of intensification of a tropical cyclone is larger than that of the uniform flow. A TC on a β-plane intensifies slower than one on an f-plane. The main physical characteristic that distinguishes the experiments is the asymmetric thermodynamic (including convective) and dynamic structures present when either a uniform flow or β-effect is introduced. But a fairly symmetric TC structure is simulated on an f-plane. The magnitude of the warm core and the associated subsidence are found to be responsible for such simulated intensity changes. On an f-plane, the convection tends to be symmetric, which results in strong upper-level convergence near the center and hence strong forced subsidence and a very warm core. On the other hand, horizontal advection of temperature cancels part of the adiabatic heating and results in less warming of the core, and hence the TC is not as intense. This advective process is due to the tilt of the vortex as a result of the β-effect. A similar situation occurs in the presence of a uniform flow. Thus, the asymmetric horizontal advection of temperature plays an important role in the temperature distribution. Dynamically, the asymmetric angular momentum (AM) flux is very small on an f-plane throughout the troposphere. However, the total AM exports at the upper levels for a TC either on a β-plane or with a uniform flow environment are larger because of an increase of the asymmetric as well as symmetric AM export on the plane at radii >450 km, and hence there is a lesser intensification.
文摘A 62-year-old woman was admitted to our hospital in2011 because of recurrent abdominal pain,nausea and constipation for six months.Computed tomography enterography(CTE)showed tortuous thread-like calcifications in the ileocolic vein and right colic vein,while colonoscopy revealed purple-blue mucosa extending from the cecum to the splenic flexure.Based on the results of these tests,the patient was diagnosed with idiopathic mesenteric phlebosclerosis(IMP).She had a history of Chinese medical liquor intake for one and a half years and her symptoms subsided after conservative treatment.In 2013,a 63-year-old male patient who presented with recurrent lower right abdominal pain,bloating,melena and diarrhea for fifteen months was admitted to our institution.Colonoscopy and CTE led to the diagnosis of IMP.He also used Chinese medical liquor for approximately 12 years.The patient underwent total colectomy and the postoperative course was uneventful.We searched for previously published reports on similar cases and analyzed the clinical data of 50 cases identified in PubMed.As some of these patients admitted use of Chinese medicines,we hypothesize that Chinese medicines may play a role in the pathogenesis of IMP.
