A time-resolved x-ray diffraction technique is employed to monitor the structural transformation of laser-shocked bismuth.Results reveal a retarded transformation from the shock-induced Bi-Ⅴphase to a metastable Bi-...A time-resolved x-ray diffraction technique is employed to monitor the structural transformation of laser-shocked bismuth.Results reveal a retarded transformation from the shock-induced Bi-Ⅴphase to a metastable Bi-Ⅳphase during the shock release,instead of the thermodynamically stable Bi-Ⅲphase.The emergence of the metastable Bi-Ⅳphase is understood by the competitive interplay between two transformation pathways towards the Bi-Ⅳand Bi-Ⅲ,respectively.The former is more rapid than the latter because the Bi-Ⅴto B-Ⅳtransformation is driven by interaction between the closest atoms while the Bi-Ⅴto B-Ⅲtransformation requires interaction between the second-closest atoms.The nucleation time for the Bi-Ⅴto Bi-Ⅳtransformation is determined to be 5.1±0.9 ns according to a classical nucleation model.This observation demonstrates the importance of the formation of the transient metastable phases,which can change the phase transformation pathway in a dynamic process.展开更多
A 78-year-old woman presented with fever, severe abdominal pain, and distension.She had been institutionalized for depression and senile dementia.Laboratory examinations disclosed a leucocytosis(WBC:12 500/μL) and el...A 78-year-old woman presented with fever, severe abdominal pain, and distension.She had been institutionalized for depression and senile dementia.Laboratory examinations disclosed a leucocytosis(WBC:12 500/μL) and elevated levels of serum C-reactive protein(2.8 mEq/L).Diagnosis of acute cecal volvulus was made from a"coffee bean sign"on an abdominal computed tomography and a"beak sign"on a gastrographin enema.An emergent laparotomy confirmed the diagnosis and an ileo-colectomy with primary anastomosis was carried out.The patient recovered after intensive respiratory care and fluid therapy, and then returned to her former institution.A review of Japanese literature disclosed that:(1) a marked increase of aged patients with mental disability presenting with cecal volvulus,(2) adoption of ileo-colectomy as the standard surgical procedure, and(3) improved survival of the patients, were observed in the last decade.展开更多
基金supported by the National Natural Science Foundation of China (Grant No.12072331)the Science Challenge Project (Grant No.TZ2018001)+2 种基金the Japan Society for the Promotion of Science (Grant Nos.17H04820 and 21H01677)the Foundation of the United Laboratory of High-Pressure Physics and Earthquake Scienceperformed under the approval of the Photon Factory Program Advisory Committee (Proposal Nos.2016S2-006 and 2020G680)。
文摘A time-resolved x-ray diffraction technique is employed to monitor the structural transformation of laser-shocked bismuth.Results reveal a retarded transformation from the shock-induced Bi-Ⅴphase to a metastable Bi-Ⅳphase during the shock release,instead of the thermodynamically stable Bi-Ⅲphase.The emergence of the metastable Bi-Ⅳphase is understood by the competitive interplay between two transformation pathways towards the Bi-Ⅳand Bi-Ⅲ,respectively.The former is more rapid than the latter because the Bi-Ⅴto B-Ⅳtransformation is driven by interaction between the closest atoms while the Bi-Ⅴto B-Ⅲtransformation requires interaction between the second-closest atoms.The nucleation time for the Bi-Ⅴto Bi-Ⅳtransformation is determined to be 5.1±0.9 ns according to a classical nucleation model.This observation demonstrates the importance of the formation of the transient metastable phases,which can change the phase transformation pathway in a dynamic process.
文摘A 78-year-old woman presented with fever, severe abdominal pain, and distension.She had been institutionalized for depression and senile dementia.Laboratory examinations disclosed a leucocytosis(WBC:12 500/μL) and elevated levels of serum C-reactive protein(2.8 mEq/L).Diagnosis of acute cecal volvulus was made from a"coffee bean sign"on an abdominal computed tomography and a"beak sign"on a gastrographin enema.An emergent laparotomy confirmed the diagnosis and an ileo-colectomy with primary anastomosis was carried out.The patient recovered after intensive respiratory care and fluid therapy, and then returned to her former institution.A review of Japanese literature disclosed that:(1) a marked increase of aged patients with mental disability presenting with cecal volvulus,(2) adoption of ileo-colectomy as the standard surgical procedure, and(3) improved survival of the patients, were observed in the last decade.
