In this study,a type of multilevel flying capacitor bridgeless PFC converter is proposed that permits the use of economical and efficient 100 V GaN transistors.Compared with the popular two-level totem-pole bridgeless...In this study,a type of multilevel flying capacitor bridgeless PFC converter is proposed that permits the use of economical and efficient 100 V GaN transistors.Compared with the popular two-level totem-pole bridgeless PFC converters achieved using the much more expensive 650 V GaN devices,this new design has several distinct advantages:lower component costs,lower dv/dt,lower power losses,and reduced concerns about device reliability.A 1.6 kW,5-level PFC converter prototype is designed and fabricated with an efficiency of 99.18%and a power factor of 0.99,which are experimentally demonstrated.The operation principle,design considerations,control strategy and experimental results are discussed.展开更多
The association between autoimmune disease and risk of monoclonal malignancy is well studied. Howeven monoclonal B-cell lymphocytosis （MBL） in patients with autoimmune diseases has rarely been reported. The newly pu...The association between autoimmune disease and risk of monoclonal malignancy is well studied. Howeven monoclonal B-cell lymphocytosis （MBL） in patients with autoimmune diseases has rarely been reported. The newly published 2016 revision of the World Health Organization （WHO） classification of lymphoid neoplasms has officially accepted MBL as an independent disease entity Herein, we present a case of Wegener granulomatosis （WG） with MBL.展开更多
To the Editor:A 27-year-old Chinese man presented to the hospital complaining of red nodules on the chest and back that gradually enlarged with spiking fever up to 39℃.He had nodular panniculitis when he was 21 years...To the Editor:A 27-year-old Chinese man presented to the hospital complaining of red nodules on the chest and back that gradually enlarged with spiking fever up to 39℃.He had nodular panniculitis when he was 21 years old.The family history was silent.Physical examination on admission revealed skin pigmentation,skin nodules (four,2cm × 2cm,without movement and tenderness), and red rash without pain and pruritus over the body.Laboratory tests showed pancytopenia,especially for white blood cell (WBC) and platelet (PLT),raised triglycerides (TGs)and ferritin levels, liver enzyme abnormalities,decreased albumin value,and deranged coagulation profile.展开更多
To the Editor:A 63-year-old Chinese woman was presented to West China Hospital complaining of dry eyes and mouth for 40 years and repeated epistaxis for 2 years.She was diagnosed with iron deficiency anemia(IDA)9 year...To the Editor:A 63-year-old Chinese woman was presented to West China Hospital complaining of dry eyes and mouth for 40 years and repeated epistaxis for 2 years.She was diagnosed with iron deficiency anemia(IDA)9 years ago,and primary Sjogren’s syndrome(pSS)and primary biliary cirrhosis(PBC)3 years ago.In the past 3 years,she was diagnosed and treated in West China Hospital for severe IDA.Repeated red blood cell suspension and iron sucrose supplementation showed no effect.She received gastroscopy 2 years ago and telangiectasia in the antrum was found.Thus,two argon plasma coagulations(APCs)were given.She had no abnormal family history.Physical examinations on admission showed tongue telangiectasia and dry eyes and mouth[Figure 1A].展开更多
We are pleased to receive the letter from the reader about our article Herein, we are willing to respond to some of their comments. In our case, we reported a senile Chinese man with a 2-month history of fever accompa...We are pleased to receive the letter from the reader about our article Herein, we are willing to respond to some of their comments. In our case, we reported a senile Chinese man with a 2-month history of fever accompanied by hearing loss, myalgia, elevated serum globulin, and erythrocyte sedimentation rate.展开更多
To the Editor： SAPHO syndrome is a heterogeneous disorder characterized by synovitis, ache, pustulosis, hyperostosis, and osteitis. Its diagnosis can be difficult if there are no typical skin manifestations. We repor...To the Editor： SAPHO syndrome is a heterogeneous disorder characterized by synovitis, ache, pustulosis, hyperostosis, and osteitis. Its diagnosis can be difficult if there are no typical skin manifestations. We reported a case of SAPHO syndrome which also fulfills the current diagnostic criteria, for ankylosing spondylitis （AS）.展开更多
The effect of deep cryogenic cycle treatment(DCT)on Zr_(41.2)Ti_(13.8)Cu_(12.5)Ni_(10)Be_(22.5)(Vit-1)bulk metallic glass(BMG)prepared from high-purity raw materials was investigated.After DCT,no obvious rejuvenation ...The effect of deep cryogenic cycle treatment(DCT)on Zr_(41.2)Ti_(13.8)Cu_(12.5)Ni_(10)Be_(22.5)(Vit-1)bulk metallic glass(BMG)prepared from high-purity raw materials was investigated.After DCT,no obvious rejuvenation of the samples was detected.With an increasing number of cryogenic cycles,the hardness of the samples first decreased and then increased,the room-temperature compression plasticity first increased and then generally remained unchanged,and the impact toughness underwent almost no obvious change.The absence of rejuvenation was attributed to the high fragility index(47-50)and high glass forming ability(GFA)of the material.As lower purity of the raw materials is expected in practical applications,DCT of Vit-1 BMG prepared from low-purity raw materials was also performed.After DCT,the samples prepared with the lower-purity raw materials were clearly rejuvenated,and the room-temperature mechanical properties improved significantly.Both the compression plasticity and impact toughness reached peak values after 5 cryogenic cycles.The initial impurities(including Y and O)had a complex and comprehensive effect on the deformation mechanism of the BMG during DCT.Our findings indicate that the structural heterogeneity,fragility index,and GFA of the BMG alter the effect of DCT.展开更多
基金Supported by the National Natural Science Foundation of China(51977068).
文摘In this study,a type of multilevel flying capacitor bridgeless PFC converter is proposed that permits the use of economical and efficient 100 V GaN transistors.Compared with the popular two-level totem-pole bridgeless PFC converters achieved using the much more expensive 650 V GaN devices,this new design has several distinct advantages:lower component costs,lower dv/dt,lower power losses,and reduced concerns about device reliability.A 1.6 kW,5-level PFC converter prototype is designed and fabricated with an efficiency of 99.18%and a power factor of 0.99,which are experimentally demonstrated.The operation principle,design considerations,control strategy and experimental results are discussed.
文摘The association between autoimmune disease and risk of monoclonal malignancy is well studied. Howeven monoclonal B-cell lymphocytosis （MBL） in patients with autoimmune diseases has rarely been reported. The newly published 2016 revision of the World Health Organization （WHO） classification of lymphoid neoplasms has officially accepted MBL as an independent disease entity Herein, we present a case of Wegener granulomatosis （WG） with MBL.
基金grants from National Natural Science Foundation of China (No.30901339and No.81172869) the Application Foundation Project in Sichuan Province (No.2016JY0021and No.2017JY0025).
文摘To the Editor:A 27-year-old Chinese man presented to the hospital complaining of red nodules on the chest and back that gradually enlarged with spiking fever up to 39℃.He had nodular panniculitis when he was 21 years old.The family history was silent.Physical examination on admission revealed skin pigmentation,skin nodules (four,2cm × 2cm,without movement and tenderness), and red rash without pain and pruritus over the body.Laboratory tests showed pancytopenia,especially for white blood cell (WBC) and platelet (PLT),raised triglycerides (TGs)and ferritin levels, liver enzyme abnormalities,decreased albumin value,and deranged coagulation profile.
文摘To the Editor:A 63-year-old Chinese woman was presented to West China Hospital complaining of dry eyes and mouth for 40 years and repeated epistaxis for 2 years.She was diagnosed with iron deficiency anemia(IDA)9 years ago,and primary Sjogren’s syndrome(pSS)and primary biliary cirrhosis(PBC)3 years ago.In the past 3 years,she was diagnosed and treated in West China Hospital for severe IDA.Repeated red blood cell suspension and iron sucrose supplementation showed no effect.She received gastroscopy 2 years ago and telangiectasia in the antrum was found.Thus,two argon plasma coagulations(APCs)were given.She had no abnormal family history.Physical examinations on admission showed tongue telangiectasia and dry eyes and mouth[Figure 1A].
文摘We are pleased to receive the letter from the reader about our article Herein, we are willing to respond to some of their comments. In our case, we reported a senile Chinese man with a 2-month history of fever accompanied by hearing loss, myalgia, elevated serum globulin, and erythrocyte sedimentation rate.
文摘To the Editor： SAPHO syndrome is a heterogeneous disorder characterized by synovitis, ache, pustulosis, hyperostosis, and osteitis. Its diagnosis can be difficult if there are no typical skin manifestations. We reported a case of SAPHO syndrome which also fulfills the current diagnostic criteria, for ankylosing spondylitis （AS）.
基金financially supported by the National Science Foundation for Distinguished Young Scholars of China(Grant No.51725504)the open funding via State Key Laboratory of Materials Processing and Die&Mould Technology(Grant No.P2019-011)+1 种基金the Guangdong Provincial Natural Science Foundation of China(Grant No.2020A1515011524)the Fundamental Research Funds for the Central Universities,HUST(Grant No.2018KFYRCPT001).
文摘The effect of deep cryogenic cycle treatment(DCT)on Zr_(41.2)Ti_(13.8)Cu_(12.5)Ni_(10)Be_(22.5)(Vit-1)bulk metallic glass(BMG)prepared from high-purity raw materials was investigated.After DCT,no obvious rejuvenation of the samples was detected.With an increasing number of cryogenic cycles,the hardness of the samples first decreased and then increased,the room-temperature compression plasticity first increased and then generally remained unchanged,and the impact toughness underwent almost no obvious change.The absence of rejuvenation was attributed to the high fragility index(47-50)and high glass forming ability(GFA)of the material.As lower purity of the raw materials is expected in practical applications,DCT of Vit-1 BMG prepared from low-purity raw materials was also performed.After DCT,the samples prepared with the lower-purity raw materials were clearly rejuvenated,and the room-temperature mechanical properties improved significantly.Both the compression plasticity and impact toughness reached peak values after 5 cryogenic cycles.The initial impurities(including Y and O)had a complex and comprehensive effect on the deformation mechanism of the BMG during DCT.Our findings indicate that the structural heterogeneity,fragility index,and GFA of the BMG alter the effect of DCT.
