As2S3 and As2Se3 chalcogenide 3-bridges suspended-core fibers（SCFs） are designed with shifted zero-dispersion wavelengths（ZDWs） at around 1.5 μm, 2 μm, and 2.8 μm, respectively. A generalized nonlinear Schrodin...As2S3 and As2Se3 chalcogenide 3-bridges suspended-core fibers（SCFs） are designed with shifted zero-dispersion wavelengths（ZDWs） at around 1.5 μm, 2 μm, and 2.8 μm, respectively. A generalized nonlinear Schrodinger equation is used to numerically compare supercontinuum（SC） generation in these SCFs pumped at an anomalous dispersion region nearby their ZDWs. Evolutions of the long-wavelength edge（LWE）, the power proportion in the long-wavelength region（PPL）, and spectral flatness（SF） are calculated and analyzed. Meanwhile, the optimal pump parameters and fiber length are given with LWE, PPL, and SF taken into account. For As2S3 SCFs, SC from a 14 mm-long fiber with a ZDW of 2825 nm pumped at 2870 nm can achieve the longest LWE of - 13 μm and PPL up to ～72%. For As2Se3 SCFs, the LWE of 15.5 μm and the highest PPL of ～ 87% can be achieved in a 10 mm-long fiber with ZDW of 1982 nm pumped at 2000 nm. Although the As2Se3 SCFs can achieve much longer LWE than the As2S3 SCFs, the core diameter of As2Se3 SCFs will be much smaller to obtain a similar ZDW, leading to lower damage threshold and output power. Finally, the optimal parameters for generating SC spanning over different mid-IR windows are given.展开更多
A 1-year-old male meerkat was found dead by the owner.The animal was clinically healthy and was regularly vaccinated for distemper virus.Necropsy revealed multifocal to confluent dry white areas in the myocardium,pneu...A 1-year-old male meerkat was found dead by the owner.The animal was clinically healthy and was regularly vaccinated for distemper virus.Necropsy revealed multifocal to confluent dry white areas in the myocardium,pneumonia and congestive hepatopathy.All the other organs,including gross vessels,were macroscopically normal.The heart showed histologically large,multifocal to confluent areas of mineralization of the myocardium and the wall of small coronary artery.Vascular calcifications were also observed in the hepatic portal tracts and kidneys arteries of small/medium sizes.The arterial lumen appeared narrowed and the wall thickened due to the calcification of the tunica media.In veterinary medicine,arterial mineralization is regarded as a metastatic calcification,as the result of hypercalcemia and/or hyperphosphatemia.However,today,the pathogenesis of medial artery calcification in humans seems to be the results of an active process resembling embryonic osteogenesis,rather than a mere passive process.展开更多
We report on generation of a dual-wavelength, all-fiber, passively Q-switched ytterbium-doped fiber laser using aluminum oxide nanoparticle （Al2O3-NP） thin film. A thin film of Al2O3 was prepared by embedding Al2O3-...We report on generation of a dual-wavelength, all-fiber, passively Q-switched ytterbium-doped fiber laser using aluminum oxide nanoparticle （Al2O3-NP） thin film. A thin film of Al2O3 was prepared by embedding Al2O3-NPs into a polyvinyl alcohol （PVA） as a host polymer, and then inserted between two fiber ferrules to act as a saturable absorber （SA）. By incorporating the Al2O3-PVA SA into the laser cavity, a stable dual-wavelength pulse output centered at 1050 and 1060.7nm is observed at threshold pump power of 80mW. As the pump power is gradually increased from 80 to 300mW, the repetition rate of the generated pulse increases from 16.23 to 59 kHz, while the pulse width decreases from 19 to 6μs. To the best of our knowledge, this is the first demonstration for this type of SA operating in the 1 μm region.展开更多
Pregnancy is a unique physiological state in which several changes occur.One of the most important aspects is the maternal immune system,which sets to tolerate the presence of thedeveloping fetus(a semi-allogeneic org...Pregnancy is a unique physiological state in which several changes occur.One of the most important aspects is the maternal immune system,which sets to tolerate the presence of thedeveloping fetus(a semi-allogeneic organism),while at the same time providing protection against pathogens.1 Pregnancy has long been known to affect the risk of certain cancers including breast cancer in the short term,gestational trophoblastic disease(GTD),cervical cancer,and melanoma.2,3 The reasons for the increased risk of these cancers during pregnancy are not fully understood,but several hypotheses have been proposed as the hormonal and immune system changes.展开更多
We construct a set T of space-the transformations between inertial systems that are completely equivalent for explaining the experimental evidence, by starting from two empirically based assumptions: (1) The two-way ...We construct a set T of space-the transformations between inertial systems that are completely equivalent for explaining the experimental evidence, by starting from two empirically based assumptions: (1) The two-way velocity of light is c in all inertial systems and in all directions; (2) Time dilation effects take place with the usual relativistic factor. The Lorentz transformation is an element of T and any two elements of T differ only as to a convention regarding clock synchronization. The simplest choice is to transform time independently of space coordinates (absolute synchronization) and can be called 'inerital transformation.' When accelerations are considered the equivalence is broken and the inertial transformation emerges as closest to physical reality.展开更多
基金Project supported by the National Nature Science Foundation of China(Grant Nos.61435003,61377042,61505024,and 61421002)Open Fund of State Key Laboratory of Advanced Optical Communication Systems and Networks,China(Grant No.2015GZKF004)+1 种基金Open Found of Key Laboratory of Specialty Fiber Optics and Optical Access Networks,Shanghai University,China(Grant No.SKLSFO2014-07)Open Fund of Science and Technology on Solid-State Laser Laboratory,China(Grant No.H04010501W2015000604)
文摘As2S3 and As2Se3 chalcogenide 3-bridges suspended-core fibers（SCFs） are designed with shifted zero-dispersion wavelengths（ZDWs） at around 1.5 μm, 2 μm, and 2.8 μm, respectively. A generalized nonlinear Schrodinger equation is used to numerically compare supercontinuum（SC） generation in these SCFs pumped at an anomalous dispersion region nearby their ZDWs. Evolutions of the long-wavelength edge（LWE）, the power proportion in the long-wavelength region（PPL）, and spectral flatness（SF） are calculated and analyzed. Meanwhile, the optimal pump parameters and fiber length are given with LWE, PPL, and SF taken into account. For As2S3 SCFs, SC from a 14 mm-long fiber with a ZDW of 2825 nm pumped at 2870 nm can achieve the longest LWE of - 13 μm and PPL up to ～72%. For As2Se3 SCFs, the LWE of 15.5 μm and the highest PPL of ～ 87% can be achieved in a 10 mm-long fiber with ZDW of 1982 nm pumped at 2000 nm. Although the As2Se3 SCFs can achieve much longer LWE than the As2S3 SCFs, the core diameter of As2Se3 SCFs will be much smaller to obtain a similar ZDW, leading to lower damage threshold and output power. Finally, the optimal parameters for generating SC spanning over different mid-IR windows are given.
文摘A 1-year-old male meerkat was found dead by the owner.The animal was clinically healthy and was regularly vaccinated for distemper virus.Necropsy revealed multifocal to confluent dry white areas in the myocardium,pneumonia and congestive hepatopathy.All the other organs,including gross vessels,were macroscopically normal.The heart showed histologically large,multifocal to confluent areas of mineralization of the myocardium and the wall of small coronary artery.Vascular calcifications were also observed in the hepatic portal tracts and kidneys arteries of small/medium sizes.The arterial lumen appeared narrowed and the wall thickened due to the calcification of the tunica media.In veterinary medicine,arterial mineralization is regarded as a metastatic calcification,as the result of hypercalcemia and/or hyperphosphatemia.However,today,the pathogenesis of medial artery calcification in humans seems to be the results of an active process resembling embryonic osteogenesis,rather than a mere passive process.
基金Supported by the Iraqi Ministry of Higher Education and Scientific Research and University of Baghdad
文摘We report on generation of a dual-wavelength, all-fiber, passively Q-switched ytterbium-doped fiber laser using aluminum oxide nanoparticle （Al2O3-NP） thin film. A thin film of Al2O3 was prepared by embedding Al2O3-NPs into a polyvinyl alcohol （PVA） as a host polymer, and then inserted between two fiber ferrules to act as a saturable absorber （SA）. By incorporating the Al2O3-PVA SA into the laser cavity, a stable dual-wavelength pulse output centered at 1050 and 1060.7nm is observed at threshold pump power of 80mW. As the pump power is gradually increased from 80 to 300mW, the repetition rate of the generated pulse increases from 16.23 to 59 kHz, while the pulse width decreases from 19 to 6μs. To the best of our knowledge, this is the first demonstration for this type of SA operating in the 1 μm region.
文摘Pregnancy is a unique physiological state in which several changes occur.One of the most important aspects is the maternal immune system,which sets to tolerate the presence of thedeveloping fetus(a semi-allogeneic organism),while at the same time providing protection against pathogens.1 Pregnancy has long been known to affect the risk of certain cancers including breast cancer in the short term,gestational trophoblastic disease(GTD),cervical cancer,and melanoma.2,3 The reasons for the increased risk of these cancers during pregnancy are not fully understood,but several hypotheses have been proposed as the hormonal and immune system changes.
文摘We construct a set T of space-the transformations between inertial systems that are completely equivalent for explaining the experimental evidence, by starting from two empirically based assumptions: (1) The two-way velocity of light is c in all inertial systems and in all directions; (2) Time dilation effects take place with the usual relativistic factor. The Lorentz transformation is an element of T and any two elements of T differ only as to a convention regarding clock synchronization. The simplest choice is to transform time independently of space coordinates (absolute synchronization) and can be called 'inerital transformation.' When accelerations are considered the equivalence is broken and the inertial transformation emerges as closest to physical reality.
