Si2N2O/Si3N4 nanocomposites were fabricated by liquid phase sintering of amorphous nano-sized silicon nitride powders.The intragranular microstructure was observed and researched.Intragranular microstructure's β-...Si2N2O/Si3N4 nanocomposites were fabricated by liquid phase sintering of amorphous nano-sized silicon nitride powders.The intragranular microstructure was observed and researched.Intragranular microstructure's β-Si3N4 was formed in Si2N2O matrix at the sintering temperature higher than 1650°C.It was discovered that intragranular microstructure could also disappear by transformation during high temperature annealing.Two possible mechanisms of the disappearance of intragranular microstructure were given.The effect of intragranular microstructure on main mechanical properties was also investigated.展开更多
Vanishing bile duct syndromes （VBDS） are characterized by progressive loss of small intrahepatic ducts caused by a variety of different diseases leading to chronic cholestasis, cirrhosis, and premature death from li...Vanishing bile duct syndromes （VBDS） are characterized by progressive loss of small intrahepatic ducts caused by a variety of different diseases leading to chronic cholestasis, cirrhosis, and premature death from liver failure. The majority of adult patients with VBDS suffer from primary biliary cirrhosis （PBC） and primary sclerosing cholangitis （PSC）. Ursodeoxycholic acid （UDCA）, a hydrophilic dihydroxy bile acid, is the only drug currently approved for the treatment of patients with PBC, and anticholestatic effects have been reported for several other cholestatic syndromes. Several potential mechanisms of action of UDCA have been proposed including stimulation of hepatobiliary secretion, inhibition of apoptosis and protection of cholangiocytes against toxic effects of hydrophobic bile acids.展开更多
Vanishing bone disease(Gorham-Stout syndrome) is a rare entity of unknown etiology, characterized by de struction of osseous matrix and proliferation of vascula structures, resulting in destruction and absorption o bo...Vanishing bone disease(Gorham-Stout syndrome) is a rare entity of unknown etiology, characterized by de struction of osseous matrix and proliferation of vascula structures, resulting in destruction and absorption o bone. Despite the extensive investigation of the patho genetic mechanisms of the disease, its etiology hasn'been clarified and several theories exist. The syndrome can affect one or multiple bones of the patient, includ ing the skull, the upper and lower extremities, the spine and pelvis. The clinical presentation of a patient suffer ing from vanishing bone disease includes, pain, func tional impairment and swelling of the affected region although asymptomatic cases have been reported, as well as cases in which the diagnosis was made after a pathologic fracture. In this short review we summarize the theories regarding the etiology as well as the clini cal presentation, the diagnostic approach and treat ment options of this rare disease.展开更多
This paper studies the asymptotic behavior ofweak entropy solutions to the Cauchy problem of the so-called p-system with damping. The convergence rates to nonlinear diffusion waves for weak entropy solutions are obtai...This paper studies the asymptotic behavior ofweak entropy solutions to the Cauchy problem of the so-called p-system with damping. The convergence rates to nonlinear diffusion waves for weak entropy solutions are obtained in L∞-norm or L2-norm. These convergence rates are the same to the decay rates of smooth solution obtained by Nishihara. They are proved by using the vanishing viscosity method and the elementary L2-energy method.展开更多
The research of unmanned aerial vehicles＇（UAVs＇）autonomy navigation and landing guidance with computer vision has important signifcance.However,because of the image blurring,the position of the cooperative points ...The research of unmanned aerial vehicles＇（UAVs＇）autonomy navigation and landing guidance with computer vision has important signifcance.However,because of the image blurring,the position of the cooperative points cannot be obtained accurately,and the pose estimation algorithms based on the feature points have low precision.In this research,the pose estimation algorithm of UAV is proposed based on feature lines of the cooperative object for autonomous landing.This method uses the actual shape of the cooperative-target on ground and the principle of vanishing line.Roll angle is calculated from the vanishing line.Yaw angle is calculated from the location of the target in the image.Finally,the remaining extrinsic parameters are calculated by the coordinates transformation.Experimental results show that the pose estimation algorithm based on line feature has a higher precision and is more reliable than the pose estimation algorithm based on points feature.Moreover,the error of the algorithm we proposed is small enough when the UAV is near to the landing strip,and it can meet the basic requirements of UAV＇s autonomous landing.展开更多
Vanishing bile duct syndrome(VBDS) is a group of rare disorders characterized by ductopenia,the progressive destruction and disappearance of intrahepatic bile ducts leading to cholestasis.Described in association with...Vanishing bile duct syndrome(VBDS) is a group of rare disorders characterized by ductopenia,the progressive destruction and disappearance of intrahepatic bile ducts leading to cholestasis.Described in association with medications,autoimmune disorders,cancer,transplantation,and infections,the specific mechanisms of disease are not known.To date,only 4 cases of VBDS have been reported in human immunodeficiency virus(HIV) infected patients.We report 2 additional cases of HIV-associated VBDS and review the features common to the HIV-associated cases.Presentation includes hyperbilirubinemia,normal liver imaging,and negative viral and autoimmune hepatitis studies.In HIV-infected subjects,VBDS occurred at a range of CD4+ T-cell counts,in some cases following initiation or change in antiretroviral therapy.Lymphoma was associated with two cases;nevirapine,antibiotics,and viral co-infection were suggested as etiologies in the other cases.In HIV-positive patients with progressive cholestasis,early identification of VBDS and referral for transplantation may improve outcomes.展开更多
In this paper, the authors get the characterizations of the integral and Car-leson type measure both associated with the invariant gradient for little a-Bloch functions in the unit ball of Cn. As a consequence, some r...In this paper, the authors get the characterizations of the integral and Car-leson type measure both associated with the invariant gradient for little a-Bloch functions in the unit ball of Cn. As a consequence, some results of Ouyang C H, Yang W S and Zhao R H in [4] and a result of Yang W S in [10] are extended.展开更多
Vanishing bile duct syndrome (VBDS) refers to a group of disorders characterized by prolonged cholestasis as a result of destruction and disappearance ofintrahepatic bile ducts. Multiple etiologies have been indentifi...Vanishing bile duct syndrome (VBDS) refers to a group of disorders characterized by prolonged cholestasis as a result of destruction and disappearance ofintrahepatic bile ducts. Multiple etiologies have been indentifi ed including infections, neoplastic disorders, autoimmune conditions and drugs. The natural history of this condition is variable and may involve resolution of cholestasis or progression with irreversible damage. VBDS is extremely rare in human immunodeficiency virus (HIV)-infected patients and anti-retroviral therapy has never been implicated as a cause. We encountered a young pregnant female with HIV and VBDS secondary to anti-retroviral therapy. Here, we report her clinical course and outcome.展开更多
Improving performance of deep learning models and reducing their training times are ongoing challenges in deep neural networks.There are several approaches proposed to address these challenges,one of which is to incre...Improving performance of deep learning models and reducing their training times are ongoing challenges in deep neural networks.There are several approaches proposed to address these challenges,one of which is to increase the depth of the neural networks.Such deeper networks not only increase training times,but also suffer from vanishing gradients problem while training.In this work,we propose gradient amplification approach for training deep learning models to prevent vanishing gradients and also develop a training strategy to enable or disable gradient amplification method across several epochs with different learning rates.We perform experiments on VGG-19 and Resnet models(Resnet-18 and Resnet-34),and study the impact of amplification parameters on these models in detail.Our proposed approach improves performance of these deep learning models even at higher learning rates,thereby allowing these models to achieve higher performance with reduced training time.展开更多
In this paper, we study the vanishing viscosity limit for non-isentropic gas dy- namics with interacting shocks. Given any entropy solution of non-isentropic gas dynamics which consists of two different families of sh...In this paper, we study the vanishing viscosity limit for non-isentropic gas dy- namics with interacting shocks. Given any entropy solution of non-isentropic gas dynamics which consists of two different families of shocks interacting at some positive time, we show that such solution is the vanishing viscosity limit of a family of smooth global solutions for a viscous system of conservation law. We remark that, after the interacting time, not only shocks but also contact discontinuity are generated.展开更多
In this paper,the authors obtain the boundedness of the fractional integral operators with variable kernels on the variable exponent generalized weighted Morrey spaces and the variable exponent vanishing generalized w...In this paper,the authors obtain the boundedness of the fractional integral operators with variable kernels on the variable exponent generalized weighted Morrey spaces and the variable exponent vanishing generalized weighted Morrey spaces.And the corresponding commutators generated by BMO function are also considered.展开更多
基金supported by National Postdoctoral Foundation of China (Grant No.20060400787)Science Foundation of China (Grant No.50901066)
文摘Si2N2O/Si3N4 nanocomposites were fabricated by liquid phase sintering of amorphous nano-sized silicon nitride powders.The intragranular microstructure was observed and researched.Intragranular microstructure's β-Si3N4 was formed in Si2N2O matrix at the sintering temperature higher than 1650°C.It was discovered that intragranular microstructure could also disappear by transformation during high temperature annealing.Two possible mechanisms of the disappearance of intragranular microstructure were given.The effect of intragranular microstructure on main mechanical properties was also investigated.
文摘Vanishing bile duct syndromes （VBDS） are characterized by progressive loss of small intrahepatic ducts caused by a variety of different diseases leading to chronic cholestasis, cirrhosis, and premature death from liver failure. The majority of adult patients with VBDS suffer from primary biliary cirrhosis （PBC） and primary sclerosing cholangitis （PSC）. Ursodeoxycholic acid （UDCA）, a hydrophilic dihydroxy bile acid, is the only drug currently approved for the treatment of patients with PBC, and anticholestatic effects have been reported for several other cholestatic syndromes. Several potential mechanisms of action of UDCA have been proposed including stimulation of hepatobiliary secretion, inhibition of apoptosis and protection of cholangiocytes against toxic effects of hydrophobic bile acids.
文摘Vanishing bone disease(Gorham-Stout syndrome) is a rare entity of unknown etiology, characterized by de struction of osseous matrix and proliferation of vascula structures, resulting in destruction and absorption o bone. Despite the extensive investigation of the patho genetic mechanisms of the disease, its etiology hasn'been clarified and several theories exist. The syndrome can affect one or multiple bones of the patient, includ ing the skull, the upper and lower extremities, the spine and pelvis. The clinical presentation of a patient suffer ing from vanishing bone disease includes, pain, func tional impairment and swelling of the affected region although asymptomatic cases have been reported, as well as cases in which the diagnosis was made after a pathologic fracture. In this short review we summarize the theories regarding the etiology as well as the clini cal presentation, the diagnostic approach and treat ment options of this rare disease.
基金The research was supported by the Zheng Ge Ru Foundation of CUHK and two grants from the National Natural Science Foundation of China(#10171037) sponsored by the Scientific Research Foundation for the Returned Overseas Chinese ScholarsState Education Ministry respectively.
文摘This paper studies the asymptotic behavior ofweak entropy solutions to the Cauchy problem of the so-called p-system with damping. The convergence rates to nonlinear diffusion waves for weak entropy solutions are obtained in L∞-norm or L2-norm. These convergence rates are the same to the decay rates of smooth solution obtained by Nishihara. They are proved by using the vanishing viscosity method and the elementary L2-energy method.
基金supported by the NUAA Fundamental Research Funds(No.NS2013034)
文摘The research of unmanned aerial vehicles＇（UAVs＇）autonomy navigation and landing guidance with computer vision has important signifcance.However,because of the image blurring,the position of the cooperative points cannot be obtained accurately,and the pose estimation algorithms based on the feature points have low precision.In this research,the pose estimation algorithm of UAV is proposed based on feature lines of the cooperative object for autonomous landing.This method uses the actual shape of the cooperative-target on ground and the principle of vanishing line.Roll angle is calculated from the vanishing line.Yaw angle is calculated from the location of the target in the image.Finally,the remaining extrinsic parameters are calculated by the coordinates transformation.Experimental results show that the pose estimation algorithm based on line feature has a higher precision and is more reliable than the pose estimation algorithm based on points feature.Moreover,the error of the algorithm we proposed is small enough when the UAV is near to the landing strip,and it can meet the basic requirements of UAV＇s autonomous landing.
基金Supported by The Intramural Research Programs of the National Institutes of Health Clinical Center and the National Institute of Allergy and Infectious Diseases
文摘Vanishing bile duct syndrome(VBDS) is a group of rare disorders characterized by ductopenia,the progressive destruction and disappearance of intrahepatic bile ducts leading to cholestasis.Described in association with medications,autoimmune disorders,cancer,transplantation,and infections,the specific mechanisms of disease are not known.To date,only 4 cases of VBDS have been reported in human immunodeficiency virus(HIV) infected patients.We report 2 additional cases of HIV-associated VBDS and review the features common to the HIV-associated cases.Presentation includes hyperbilirubinemia,normal liver imaging,and negative viral and autoimmune hepatitis studies.In HIV-infected subjects,VBDS occurred at a range of CD4+ T-cell counts,in some cases following initiation or change in antiretroviral therapy.Lymphoma was associated with two cases;nevirapine,antibiotics,and viral co-infection were suggested as etiologies in the other cases.In HIV-positive patients with progressive cholestasis,early identification of VBDS and referral for transplantation may improve outcomes.
文摘In this paper, the authors get the characterizations of the integral and Car-leson type measure both associated with the invariant gradient for little a-Bloch functions in the unit ball of Cn. As a consequence, some results of Ouyang C H, Yang W S and Zhao R H in [4] and a result of Yang W S in [10] are extended.
文摘Vanishing bile duct syndrome (VBDS) refers to a group of disorders characterized by prolonged cholestasis as a result of destruction and disappearance ofintrahepatic bile ducts. Multiple etiologies have been indentifi ed including infections, neoplastic disorders, autoimmune conditions and drugs. The natural history of this condition is variable and may involve resolution of cholestasis or progression with irreversible damage. VBDS is extremely rare in human immunodeficiency virus (HIV)-infected patients and anti-retroviral therapy has never been implicated as a cause. We encountered a young pregnant female with HIV and VBDS secondary to anti-retroviral therapy. Here, we report her clinical course and outcome.
基金supported in part by an NVIDIA Academic Hardware Grant
文摘Improving performance of deep learning models and reducing their training times are ongoing challenges in deep neural networks.There are several approaches proposed to address these challenges,one of which is to increase the depth of the neural networks.Such deeper networks not only increase training times,but also suffer from vanishing gradients problem while training.In this work,we propose gradient amplification approach for training deep learning models to prevent vanishing gradients and also develop a training strategy to enable or disable gradient amplification method across several epochs with different learning rates.We perform experiments on VGG-19 and Resnet models(Resnet-18 and Resnet-34),and study the impact of amplification parameters on these models in detail.Our proposed approach improves performance of these deep learning models even at higher learning rates,thereby allowing these models to achieve higher performance with reduced training time.
基金Xiaoding Shi was supported by National Natural Sciences Foundation of China(11471321)Yan Yong was supported by National Natural Sciences Foundation of China(11201301)
文摘In this paper, we study the vanishing viscosity limit for non-isentropic gas dy- namics with interacting shocks. Given any entropy solution of non-isentropic gas dynamics which consists of two different families of shocks interacting at some positive time, we show that such solution is the vanishing viscosity limit of a family of smooth global solutions for a viscous system of conservation law. We remark that, after the interacting time, not only shocks but also contact discontinuity are generated.
基金supported by the National Natural Science Foundation of China(No.11561062)Natural Science Foundation of Gansu Province(21JR1RM337).
文摘In this paper,the authors obtain the boundedness of the fractional integral operators with variable kernels on the variable exponent generalized weighted Morrey spaces and the variable exponent vanishing generalized weighted Morrey spaces.And the corresponding commutators generated by BMO function are also considered.
