We experimentally demonstrate that a tunable supercontinuum（SC） can be generated in a Yb3＋-doped microstructure fiber by the concept of wavelength conversion with a Ti：sapphire femtosecond（fs） laser as the pump....We experimentally demonstrate that a tunable supercontinuum（SC） can be generated in a Yb3＋-doped microstructure fiber by the concept of wavelength conversion with a Ti：sapphire femtosecond（fs） laser as the pump.Experimental results show that an emission light around 1040 nm in an anomalous dispersion region is first generated and amplified by fs pulses in the normal dispersion region. Then, SC spectra from 1100 to 1380 nm and 630 to 840 nm can be achieved by combined effects of higher-order soliton fission and Raman soliton self-frequency shift in the anomalous dispersion region and self-phase modulation, dispersive wave, and four-wave mixing in the normal dispersion region. It is also demonstrated that the 20 nm change of pump results in a 280 nm broadband shift of soliton and the further red-shift of soliton is limited by OH-absorption at 1380 nm.展开更多
Analyzing the spatial patterns of net primary productivity(NPP)and its driving forces in transnational areas provides a solid basis for understanding regional ecological processes and ecosystem services.However,the sp...Analyzing the spatial patterns of net primary productivity(NPP)and its driving forces in transnational areas provides a solid basis for understanding regional ecological processes and ecosystem services.However,the spatial patterns of NPP and its driving forces have been poorly understood on multiple scales in transnational areas.In this study,the spatial patterns of NPP in the transnational area of the Tumen River(TATR)in 2016 were simulated using the Carnegie Ames Stanford Approach(CASA)model,and its driving forces were analyzed using a stepwise multiple linear regression model.We found that the total amount of NPP in the TATR in 2016 was approximately 14.53 TgC.The amount of NPP on the Chinese side(6.23 TgC)was larger than those on the other two sides,accounting for 42.88%of the total volume of the entire region.Among different land-use and land-cover(LULC)types,the amount of NPP of the broadleaf forest was the largest(11.22 TgC),while the amount of NPP of the bare land was the smallest.The NPP per unit area was about 603.21 gC/(m2 yr)across the entire region,while the NPP per unit area on the Chinese side was the largest,followed by the Russian side and the DPRK's side.The spatial patterns of NPP were influenced by climate,topography,soil texture,and human activities.In addition,the driving forces of the spatial patterns of NPP in the TATR had an obvious scaling effect,which was mainly caused by the spatial heterogeneity of climate,topography,soil texture,and human activities.We suggest that effective land management policies with cooperation among China,the DPRK,and Russia are needed to maintain NPP and improve environmental sustainability in the TATR.展开更多
In recent years the evolution of olfactory bulb periglomerular cells,as well as the function of periglomerular cells in olfactory encoding,has attracted increasing attention.Studies of neural information encoding base...In recent years the evolution of olfactory bulb periglomerular cells,as well as the function of periglomerular cells in olfactory encoding,has attracted increasing attention.Studies of neural information encoding based on the analysis of simulation and modeling have given rise to electrophysiological models of periglomerular cells,which have an important role in the understanding of the biology of these cells.In this review we provide a brief introduction to the anatomy of the olfactory system and the cell types in the olfactory bulb.We elaborate on the latest progress in the study of the heterogeneity of periglomerular cells based on different classification criteria,such as molecular markers,structure,ion channels and action potentials.Then,we discuss the several existing electrophysiological models of periglomerular cells,and we highlight the problems and defects of these models.Finally,considering our present work,we propose a future direction for electrophysiological investigations of periglomerular cells and for the modeling of periglomerular cells and olfactory information encoding.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 61735011the Natural Science Foundation of Hebei Province under Grant Nos F2016203389 and F2018105036+2 种基金the Science and Technology Research Project of College and University in Hebei Province under Grant No BJ2017108the Open Subject of Jiangsu Key Laboratory of Meteorological Observation and Information Processing under Grant No KDXS1107the Science and Technology Project of Tangshan City under Grant No 17130257a
文摘We experimentally demonstrate that a tunable supercontinuum（SC） can be generated in a Yb3＋-doped microstructure fiber by the concept of wavelength conversion with a Ti：sapphire femtosecond（fs） laser as the pump.Experimental results show that an emission light around 1040 nm in an anomalous dispersion region is first generated and amplified by fs pulses in the normal dispersion region. Then, SC spectra from 1100 to 1380 nm and 630 to 840 nm can be achieved by combined effects of higher-order soliton fission and Raman soliton self-frequency shift in the anomalous dispersion region and self-phase modulation, dispersive wave, and four-wave mixing in the normal dispersion region. It is also demonstrated that the 20 nm change of pump results in a 280 nm broadband shift of soliton and the further red-shift of soliton is limited by OH-absorption at 1380 nm.
文摘Analyzing the spatial patterns of net primary productivity(NPP)and its driving forces in transnational areas provides a solid basis for understanding regional ecological processes and ecosystem services.However,the spatial patterns of NPP and its driving forces have been poorly understood on multiple scales in transnational areas.In this study,the spatial patterns of NPP in the transnational area of the Tumen River(TATR)in 2016 were simulated using the Carnegie Ames Stanford Approach(CASA)model,and its driving forces were analyzed using a stepwise multiple linear regression model.We found that the total amount of NPP in the TATR in 2016 was approximately 14.53 TgC.The amount of NPP on the Chinese side(6.23 TgC)was larger than those on the other two sides,accounting for 42.88%of the total volume of the entire region.Among different land-use and land-cover(LULC)types,the amount of NPP of the broadleaf forest was the largest(11.22 TgC),while the amount of NPP of the bare land was the smallest.The NPP per unit area was about 603.21 gC/(m2 yr)across the entire region,while the NPP per unit area on the Chinese side was the largest,followed by the Russian side and the DPRK's side.The spatial patterns of NPP were influenced by climate,topography,soil texture,and human activities.In addition,the driving forces of the spatial patterns of NPP in the TATR had an obvious scaling effect,which was mainly caused by the spatial heterogeneity of climate,topography,soil texture,and human activities.We suggest that effective land management policies with cooperation among China,the DPRK,and Russia are needed to maintain NPP and improve environmental sustainability in the TATR.
基金supported by the National Natural Science Foundation of China (Grant Nos. 30300083,30800248,60875078,and 81171416)the Natural Science Foundation of Zhejiang Province (Grant No.Z1080300)
文摘In recent years the evolution of olfactory bulb periglomerular cells,as well as the function of periglomerular cells in olfactory encoding,has attracted increasing attention.Studies of neural information encoding based on the analysis of simulation and modeling have given rise to electrophysiological models of periglomerular cells,which have an important role in the understanding of the biology of these cells.In this review we provide a brief introduction to the anatomy of the olfactory system and the cell types in the olfactory bulb.We elaborate on the latest progress in the study of the heterogeneity of periglomerular cells based on different classification criteria,such as molecular markers,structure,ion channels and action potentials.Then,we discuss the several existing electrophysiological models of periglomerular cells,and we highlight the problems and defects of these models.Finally,considering our present work,we propose a future direction for electrophysiological investigations of periglomerular cells and for the modeling of periglomerular cells and olfactory information encoding.
