1.Introduction Silicon photonic integration is considered to be one of the most promising techniques in realizing high-density photonic integrated circuits because of its compact device size and CMOS compatible fabric...1.Introduction Silicon photonic integration is considered to be one of the most promising techniques in realizing high-density photonic integrated circuits because of its compact device size and CMOS compatible fabrication process.However,due to the large index contrast of silicon waveguides,silicon photonic devices are affected by the large polarization mode dispersion,polarization dependent loss and polarization dependent wavelength characteristics.Polarization transparent circuits and polarization diversity schemes,which have polarization rotators and splitters as common key devices,have been proposed to solve this issue[1–3].展开更多
Ecological vulnerability refers to the degree of ecosystem disturbance,system damage,and the ability of system restoration.Although case-specific evaluations of ecological vulnerability are progressing rapidly,they ha...Ecological vulnerability refers to the degree of ecosystem disturbance,system damage,and the ability of system restoration.Although case-specific evaluations of ecological vulnerability are progressing rapidly,they have been carried out mainly in areas with intensive human activities or in harsh natural environments.Using the Web of ScienceTM core collection,this review paper summarized studies on ecological vulnerability published from 2000 to 2022 and analyzed in depth major case studies.It was found that traditional ecological vulnerability research has been addressed largely in terms of assessment models,data processing models,and analysis of influencing factors,however there was a lack of research on the process of vulnerability transformation.Because the vulnerability transformation in a hierarchical vulnerability index system is regulated by multiple factors in a heterogeneous region,it is urgent to understand how the ecological vulnerability in a region evolves from one level to another over time.Therefore this paper put forward the new perspective of research,i.e.,applying quantitative analysis to identification of regulating factors and exploring the mechanisms of ecological vulnerability transformation.This new perspective could assist in monitoring the complex spatiotemporal changes in ecological vulnerability and taking necessary measures to prevent from decline of ecological stability.展开更多
基金supported by the National Key Research and Development Program of China (No. 2016YFB0402505)the National Science Foundation of China (NSFC) (No. 61575189 and No. 61635011)
文摘1.Introduction Silicon photonic integration is considered to be one of the most promising techniques in realizing high-density photonic integrated circuits because of its compact device size and CMOS compatible fabrication process.However,due to the large index contrast of silicon waveguides,silicon photonic devices are affected by the large polarization mode dispersion,polarization dependent loss and polarization dependent wavelength characteristics.Polarization transparent circuits and polarization diversity schemes,which have polarization rotators and splitters as common key devices,have been proposed to solve this issue[1–3].
基金This research was funded by Shaanxi Science and Technology Department(2022JQ-282)National Natural Science Foundation of China(42007415)。
文摘Ecological vulnerability refers to the degree of ecosystem disturbance,system damage,and the ability of system restoration.Although case-specific evaluations of ecological vulnerability are progressing rapidly,they have been carried out mainly in areas with intensive human activities or in harsh natural environments.Using the Web of ScienceTM core collection,this review paper summarized studies on ecological vulnerability published from 2000 to 2022 and analyzed in depth major case studies.It was found that traditional ecological vulnerability research has been addressed largely in terms of assessment models,data processing models,and analysis of influencing factors,however there was a lack of research on the process of vulnerability transformation.Because the vulnerability transformation in a hierarchical vulnerability index system is regulated by multiple factors in a heterogeneous region,it is urgent to understand how the ecological vulnerability in a region evolves from one level to another over time.Therefore this paper put forward the new perspective of research,i.e.,applying quantitative analysis to identification of regulating factors and exploring the mechanisms of ecological vulnerability transformation.This new perspective could assist in monitoring the complex spatiotemporal changes in ecological vulnerability and taking necessary measures to prevent from decline of ecological stability.