Variations in ice mass deform the Earth and modify its gravity field,a process known as Glacial Isostatic Adjustment(GIA).GIA in Antarctica remains poorly constrained due to the cumulative effect of past and present i...Variations in ice mass deform the Earth and modify its gravity field,a process known as Glacial Isostatic Adjustment(GIA).GIA in Antarctica remains poorly constrained due to the cumulative effect of past and present ice-mass changes,the unknown history of the past ice-mass change,and the uncertainties on the mechanical properties of the Earth.This paper investigates the effect of using Andrade and Burgers viscoelastic rheologies,rather than the commonly used Maxwell rheology,to model GIA-induced deformation in Antarctica.The Love number and Green's function formalism are used to compute the radial surface displacements and the gravity changes induced by the past and present ice-mass changes.We consider an Earth model whose elastic properties and radial structure are averaged from the Preliminary Reference Earth Model and two viscosity profiles to account for the recently published results on the present ice-mass changes.Using the three rheological laws affects the temporal response of the Earth differently,leading to smaller discrepancies than those induced by the two viscosity structures.The differences are the largest between Maxwell and Burgers rheologies during the 100-1000 years following the beginning of the surface-mass change.Results show that using the Andrade and Burgers rheologies allows the Earth to respond on decennial to centennial time scales,up to 10 m more than Maxwell.Considering only the recent ice-mass changes,the deformation rates derived from Burgers and Andrade rheologies are several times larger than those estimated by Maxwell rheology.展开更多
Undifferentiated carcinoma with osteoclast-like giant cells of the pancreas(UCOGCP) is an unusual pancreatic neoplasm that represents < 1% of all pancreatic malignancies. Moreover, the giant cells of UCOGCP morphol...Undifferentiated carcinoma with osteoclast-like giant cells of the pancreas(UCOGCP) is an unusual pancreatic neoplasm that represents < 1% of all pancreatic malignancies. Moreover, the giant cells of UCOGCP morphologically resemble the benign giant cells of bone tumors. Due to the rarity of this tumor type, the histogenesis and biologic behavior of UCOGCP remain controversial. Here, we report a case of UCOGCP that exhibited an invasive growth pattern involving infiltration of the adjacent bowel loop and portal vein,as well as superior mesenteric vein thrombosis. The patient underwent a distal pancreatectomy with splenectomy and partial colectomy, followed by four cycles of gemcitabine chemotherapy. No evidence of recurrence was detected after ten years. In addition to this case, clinical information on other UCOGCP cases reported in the English literature is summarized.展开更多
据美国商业情报研究机构全球行业分析公司（Global Industry Analysts，Inc．，GIA）2011年8月最新的研究报告显示，2017年全球碳酸钙产能将达到1．14亿t／a。其中造纸行业对沉淀碳酸钙（PCC）和纳米碳酸钙不断增长的需求是碳酸钙产能...据美国商业情报研究机构全球行业分析公司（Global Industry Analysts，Inc．，GIA）2011年8月最新的研究报告显示，2017年全球碳酸钙产能将达到1．14亿t／a。其中造纸行业对沉淀碳酸钙（PCC）和纳米碳酸钙不断增长的需求是碳酸钙产能持续攀升的主要原因，而造纸行业酸法工艺向碱法工艺的转变则对碳酸钙市场供需影响甚微。展开更多
基金partly funded by the Centre National d'Etudes Spatiales(CNES)through the TOSCA program。
文摘Variations in ice mass deform the Earth and modify its gravity field,a process known as Glacial Isostatic Adjustment(GIA).GIA in Antarctica remains poorly constrained due to the cumulative effect of past and present ice-mass changes,the unknown history of the past ice-mass change,and the uncertainties on the mechanical properties of the Earth.This paper investigates the effect of using Andrade and Burgers viscoelastic rheologies,rather than the commonly used Maxwell rheology,to model GIA-induced deformation in Antarctica.The Love number and Green's function formalism are used to compute the radial surface displacements and the gravity changes induced by the past and present ice-mass changes.We consider an Earth model whose elastic properties and radial structure are averaged from the Preliminary Reference Earth Model and two viscosity profiles to account for the recently published results on the present ice-mass changes.Using the three rheological laws affects the temporal response of the Earth differently,leading to smaller discrepancies than those induced by the two viscosity structures.The differences are the largest between Maxwell and Burgers rheologies during the 100-1000 years following the beginning of the surface-mass change.Results show that using the Andrade and Burgers rheologies allows the Earth to respond on decennial to centennial time scales,up to 10 m more than Maxwell.Considering only the recent ice-mass changes,the deformation rates derived from Burgers and Andrade rheologies are several times larger than those estimated by Maxwell rheology.
文摘Undifferentiated carcinoma with osteoclast-like giant cells of the pancreas(UCOGCP) is an unusual pancreatic neoplasm that represents < 1% of all pancreatic malignancies. Moreover, the giant cells of UCOGCP morphologically resemble the benign giant cells of bone tumors. Due to the rarity of this tumor type, the histogenesis and biologic behavior of UCOGCP remain controversial. Here, we report a case of UCOGCP that exhibited an invasive growth pattern involving infiltration of the adjacent bowel loop and portal vein,as well as superior mesenteric vein thrombosis. The patient underwent a distal pancreatectomy with splenectomy and partial colectomy, followed by four cycles of gemcitabine chemotherapy. No evidence of recurrence was detected after ten years. In addition to this case, clinical information on other UCOGCP cases reported in the English literature is summarized.
文摘据美国商业情报研究机构全球行业分析公司（Global Industry Analysts，Inc．，GIA）2011年8月最新的研究报告显示，2017年全球碳酸钙产能将达到1．14亿t／a。其中造纸行业对沉淀碳酸钙（PCC）和纳米碳酸钙不断增长的需求是碳酸钙产能持续攀升的主要原因，而造纸行业酸法工艺向碱法工艺的转变则对碳酸钙市场供需影响甚微。
