Intense frequency upconversion fluorescence of Er3+/Yb3+ co-doped lithium-strontium-lead-bismuth glasses

Infrared-to-visible upconversion fluorescence of Er(3+)/Yb(3+) co-doped lithium-strontium-lead-bismuth (LSPB) glasses for developing potential upconversion lasers has been studied under 975-nm excitation. Based on the results of energy transfer efficiency and upconversion spectra, the optimal Yb(3+)-Er(3+) concentration ratio is found to be 5:1. Intense green and red emissions centered at 525, 546, and 657 nm, corresponding to the transitions 2H_(11/2)-->4I_(15/2), 4S_(3/2)-->4I_(15/2), and 4F_(9/2)-->4I_(15/2), respectively, were observed. The quadratic dependence of the 525-, 546-, and 657-nm emissions on excitation power indicates that a two-photon absorption process occurs under 975-nm excitation. The high-populated 4I_(11/2) level is supposed to serve as the intermediate state responsible for the upconversion processes. The intense upconversion luminescence of Er(3+)/Yb(3+) co-doped LSPB glasses may be a potentially useful material for developing upconversion optical devices.

Planar waveguides formed in a new chemically stable Er3+/Yb3+ co-doped phosphate glass

A new Er(3+)/Yb(3+) co-doped phosphate glass has been prepared, which exhibits good chemical durability and spectralproperties. Planar graded index waveguides have been fabricated in the glass by (Ag+)-Na(+) ion exchange in a mixed melt of silver nitrate and potassium nitrate. Ion exchange is carried out by varying the process parameters such as temperature, diffusion time, and molten salt compositions. The diffusion parameters, diffusion coefficients, and activation energy are determined by the guidelines of fabricated waveguides, which are determined by the input prism coupling technique.

Characterization of Er3+-doped Na2O-WO3-TeO2 glass for ion-exchanged waveguide amplifiers and lasers

Er^(3+)-doped Na2O-WO3-TeO2 glass consistent with standard ion-exchange technology has been fabricated and characterized. The measured absorption and emission spectra of the glass were analyzed by the Judd-Ofelt and McCumber theories. The intensity parameters are Ω2 = 7.01

Bounded rationality and voting decisions over 160 years : voter behavior and increasing complexity in decision-making

Using a quasi-natural voting experiment encompassing a 160-year period (1848–2009) in Switzerland, we investigate whether a higher level of complexity leads to increased reliance on trusted parliamentary representatives. We find that when more referenda are held on the same day, constituents are more likely to refer to parliamentary recommendations when making their decisions. This finding holds true even when we narrow our focus to referenda with a relatively lower voter turnout on days on which more than one referendum is held. We also demonstrate that when constituents face a higher level of complexity, they follow the parliamentary recommendations rather than those of interest groups. "Viewed as a geometric figure, the ant’s path is irregular, complex, hard to describe. But its complexity is really a complexity in the surface of the beach, not a complexity in the ant." ([1] p. 51)

Plan uchastka kolonizat︠s︡ionnogo fonda pod Nº 160/7, Krivorogskogo okruga Mikhaĭlovskogo raĭona ploshchadiʻ︠u︡ 864, 1188 gektarov

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Diário da Constituinte [gravação de vídeo] : [programa n. 160]

A Confederação Nacional dos Bispos do Brasil (CNBB) apresentou as emendas populares com o maior número de assinaturas até o momento. Elas tratam dos seguintes assuntos: preservação da vida desde a concepção, uso de verbas públicas para escolas públicas e escolas sem fins lucrativos, liberdade de ensino religioso e um último conjunto sobre a ordem econômica. Dom Candido Padim afirma que a reforma agrária é questão fundamental para o atendimento das aspirações populares. Todos os constituintes concordam que as relações no campo devem ser mudadas, mas cada um tem uma visão diferente do problema. O Deputado Virgílio Galassi (PDS-MG) defende uma reforma agrária sem objetivos políticos, mas com inteligência e objetividade para criar novos proprietários rurais. O Deputado Evaldo Gonçalves (PFL-PB) considera que, no Nordeste, uma grande reforma agrária seria realizar programas de irrigação e açudagem. O Deputado Oswaldo Almeida (PL-RJ) diz ser preciso desenvolver uma política agrícola que possa fixar o homem no campo. O Deputado Ulysses Guimarães, Presidente da Assembleia Nacional Constituinte (ANC), anunciou a pauta das sessões extras para tratar dos temas polêmicos. O Deputado Plínio Arruda Sampaio (PT- SP) informa que preferiria que as sessões fossem pela manhã ou pela tarde, para permitir que a imprensa tivesse melhores condições de colher os depoimentos. O Deputado Tito Costa (PMDB-SP) afirma que as sessões extras serão benéficas para o aprimoramento da Constituição.

Science-based restoration monitoring of coastal habitats, Volume One: A framework for monitoring plans under the Estuaries and Clean Waters Act of 2000 (Public Law 160-457)

Executive Summary: The Estuary Restoration Act of 2000 (ERA), Title I of the Estuaries and Clean Waters Act of 2000, was created to promote the restoration of habitats along the coast of the United States (including the US protectorates and the Great Lakes). The NOAA National Centers for Coastal Ocean Science was charged with the development of a guidance manual for monitoring plans under this Act. This guidance manual, titled Science-Based Restoration Monitoring of Coastal Habitats, is written in two volumes. It provides technical assistance, outlines necessary steps, and provides useful tools for the development and implementation of sound scientific monitoring of coastal restoration efforts. In addition, this manual offers a means to detect early warnings that the restoration is on track or not, to gauge how well a restoration site is functioning, to coordinate projects and efforts for consistent and successful restoration, and to evaluate the ecological health of specific coastal habitats both before and after project completion (Galatowitsch et al. 1998). The following habitats have been selected for discussion in this manual: water column, rock bottom, coral reefs, oyster reefs, soft bottom, kelp and other macroalgae, rocky shoreline, soft shoreline, submerged aquatic vegetation, marshes, mangrove swamps, deepwater swamps, and riverine forests. The classification of habitats used in this document is generally based on that of Cowardin et al. (1979) in their Classification of Wetlands and Deepwater Habitats of the United States, as called for in the ERA Estuary Habitat Restoration Strategy. This manual is not intended to be a restoration monitoring “cookbook” that provides templates of monitoring plans for specific habitats. The interdependence of a large number of site-specific factors causes habitat types to vary in physical and biological structure within and between regions and geographic locations (Kusler and Kentula 1990). Monitoring approaches used should be tailored to these differences. However, even with the diversity of habitats that may need to be restored and the extreme geographic range across which these habitats occur, there are consistent principles and approaches that form a common basis for effective monitoring. Volume One, titled A Framework for Monitoring Plans under the Estuaries and Clean Waters Act of 2000, begins with definitions and background information. Topics such as restoration, restoration monitoring, estuaries, and the role of socioeconomics in restoration are discussed. In addition, the habitats selected for discussion in this manual are briefly described. (PDF contains 116 pages)

16×0．8nm Si基SiO2阵列波导光栅设计、制备及测试

叙述了一个完整的16通道硅基二氧化硅阵列波导光栅(AWG)的设计、制备及测试过程。通道间隔为0．8nm(100GHz)，解复用器的插入损耗为16．8dB，其中材料损耗为11．95dB，相邻通道串扰小于一17dB，通道插损非均匀性小于2．2dB。

Design,Fabrication,and Testing of Single-Side Alignment of 16×0.8nm Arrayed-Waveguide Grating

A novel design of 100GHz-spaced 16channel arrayed-waveguide grating (AWG) based on silica-on-silicon chip is reported.AWG is achieved by adding a Y-branch to the AWG and arranging the input/output channel in a neat row,so the whole configuration can be aligned and packaged using only one fiber-array.This configuration can decrease the device's size,enlarge the minimum radius of curvature,save time on polishing and alignment,and reduce the chip's fabrication cost.

16×0.8nm硅基二氧化硅阵列波导光栅设计

给出了更为合理的阵列波导光栅(AWG)的设计原则.在设计时兼顾了输出谱的非均匀性Lu和输出通道数N的要求,克服了设计中可能引起通道数N丢失和不考虑输出谱非均匀性Lu的缺点.用该方法设计了折射率差为0.75%和16×0.8nm的硅基二氧化硅AWG.采用广角有限差分束传播方法(FD-BPM)对所设计的AWG进行了输出谱的模拟,得到了插损为-1.5dB、串扰为-48dB、通道非均匀性约为1dB的AWG,设计指标达到了商用要求。

16×0.8nm硅基二氧化硅AWG性能优化

对设计的折射率差为0.75%的16×0.8 nm硅基二氧化硅阵列波导光栅(AWG),围绕插损和串扰问题,采用广角有限差分束传播方法(FD-BPM)进行了数值模拟和优化.通过优化在输入波导、阵列波导的喇叭口,得到了插损为1.5 dB、串扰为-48 dB的AWG,优化后的指标已达到商用要求.