检索结果-南通市图书馆

Intermodal group-velocity engineering for broadband nonlinear optics

Photonics Research 2019年第1期7卷 1-7页

作者： jeff demas LARS RISH?J XIAO LIU GAUTAM PRABHAKAR SIDDHARTH RAMACHANDRAN Department of Electrical Engineering Boston University The Rockefeller University

Interest in the nonlinear properties of multi-mode optical waveguides has seen a recent resurgence on account of the large dimensionality afforded by the platform. The large volume of modes in these waveguides provides a new spatial degree of freedom for phase matching nonlinear optical processes. However, this spatial dimension is quantized, which narrows the conversion bandwidths of intermodal processes and constrains spectral and temporal tailoring of the light. Here we show that by engineering the relative group velocity within the spatial dimension, we can tailor the phase-matching bandwidth of intermodal parametric nonlinearities. We demonstrate group-velocity-tailored parametric nonlinear mixing between higher-order modes in a multi-mode fiber with gain bandwidths that are more than an order of magnitude larger than that previously thought possible for intermodal four-wave mixing. As evidence of the technological utility of this methodology, we seed this process to generate the first high-peak-power wavelength-tunable all-fiber quasi-CW laser in the Ti:sapphire wavelength *** generally, with the combination of intermodal interactions, which dramatically expand the phase-matching degrees of freedom for nonlinear optics, and intermodal group-velocity engineering, which enables tailoring of the bandwidth of such interactions, we showcase a platform for nonlinear optics that can be broadband while being wavelength agnostic.

关键词： nonlinear properties waveguides optical processes

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Editorial for Special Issue on Commonsense Knowledge and Reasoning:Representation,Acquisition and Applications

引用

Machine Intelligence Research 2024年第2期21卷 215-216页

作者： Kang Liu Yangqiu Song jeff Z.Pan Institute of Automation Chinese Academy of SciencesChina Hongkong University of Science and Technology China The University of Edinburgh UK

Commonsense knowledge is an important resource for humans to understand the meanings or semantics of the *** ability to learn and own commonsense knowledge is one of the major gaps between humans and *** recent research progresses about deep learning,like Transformer,pre-trained models,etc.,have made amazing breakthroughs in many fields,including computer version,natural language learning,etc.,letting the machines have rich commonsense knowledge and possess the reasoning ability is still difficult and under-resolved.

关键词： own let breakthrough

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Seasonal changes in Hermit Thrush (Catharus guttatus) song syntax

引用

Avian Research 2024年第2期15卷 172-179页

作者： Sean P.Roach Luke C.McLean jeff W.MacLeod Leslie S.Phillmore Psychology Department University of New Brunswick Saint John100 Tucker Park RoadSaint JohnNBCanada Department of Psychology and Neuroscience Dalhousie University1355 Oxford StHalifaxNSB3H 4J1Canada

In many songbird species,birdsong features phonological syntax,meaning that the units within their vocal se-quences are ordered in a non-random way that adheres to a *** such syntactical patterns have been richly described in many species,comparatively little is known about how those patterns contribute to song achieving its important *** each of song’s main functions,territorial defense and mate attraction,evidence of a role for syntax is *** species for which syntax has been thoroughly described is the Hermit Thrush(Catharus guttatus),which presents song types from their repertoires in a semi-predictable order and,in doing so,rapidly cycle up and down the frequency *** objective of the present study was to explore the importance of song syntax in the Hermit Thrush through a within-subject examination of how measures of syntax,such as the predictability of song type order within song sequences,shift over the breeding *** hypothesized that,if such syntactical characteristics are important to breeding behaviour,they would be most prominent at the start of the breeding season when activity associated with territory establishment and mate attraction is most *** revealed that,as predicted,the rigidness of song type ordering within se-quences was highest at the start of the season and declined *** song type sequences were most predictable at the vitally important early part of the breeding season fit our hypothesis that this aspect of song syntax is important to song’s functions related to territory establishment and/or mate *** work will clarify whether that role relates to one of song’s two main functions or serves song transmission in some broader way.

关键词： Birdsong Hermit Thrush Seasonal change Stereotypy Syntax

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

NEWS WORTHY CLIPS

引用

空中英语教室（高级版．彭蒙惠英语） 2024年第9期 12-14,41,42页

作者： jeff Haden 不详

Considerable research shows coffee can dramatically affect how your body and brain work.A study in Circulation found coffee can reduce the risk of stroke by 20%.Another study shows coffee can reduce your risk of cance... 详细信息

关键词： CLIPS diabetes NEWS

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Investigation on Effect of Composition on the Drying of Castables with Cement Binder

引用

China's Refractories 2024年第3期33卷 30-36页

作者： Bruno TOUZO Hirotaka GOTO Uwe KLIPPEL Josh SAYRE jeff BOGAN Calderys Paris 75016France Calderys Toyota 470-0308Japan Calderys Neuwied 56564Germany HWI West Mifflin 15122PAUSA

Monolithic refractory castables comprising a hydraulic bond are still used in a vast majority of cases because of their flexibility and robustness,despite many developments for chemical as well as non-cement castable *** drying can however be a challenge,in particular for deflocculated dense castables of the low cement castable *** publications have been released on this topic for the last ten years,but they often focused on the drying mechanisms or on the addition of drying *** paper presents some experimental results on the effect of the composition on the drying properties,especially on the effect of silicon carbide,used for its high thermal conductivity,and on the matrix *** also introduces two laboratory tests to study and iteratively improve the drying schedule of a given castable *** results show that the spalling resistance and the vapor pressure build-up are significantly influenced by the *** is also shown that the castable properties after drying can be altered if the heating rate is very high.

关键词： drying aggregate composition binding system heating rate

来源：

维普期刊数据库评论