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Low-loss microwave photonics links using hollow core fibres

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Light(Science & Applications) 2022年第8期11卷 1891-1902页

作者： Xi Zhang Zitong Feng David Marpaung Eric Numkam Fokoua Hesham Sakr john Richard Hayes Francesco Poletti David john richardson Radan Slavík Optoelectronics Research Centre University of SouthamptonSouthamptonSO171BJUK Laser Physics and Nonlinear Optics Group Faculty of Science and TechnologyMESA+Institute for NanotechnologyUniversity of TwenteEnschede7500 AEThe Netherlands

There are a host of applications in communications, sensing, and science, in which analogue signal transmission is preferred over today’s dominant digital transmission. In some of these applications, the advantage is in lower cost, while in others, it lies in superior performance. However, especially for longer analogue photonics links (up to 10 s of km), the performance is strongly limited by the impairments arising from using standard single-mode fibres (SSMF). Firstly, the three key metrics of analogue links (loss, noise figure, and dynamic range) tend to improve with received power, but this is limited by stimulated Brillouin scattering in SSMF. Further degradation is due to the chromatic dispersion of SSMF, which induces radio-frequency (RF) signal fading, increases even-order distortions, and causes phase-to-intensity-noise conversion. Further distortions still, are caused by the Kerr nonlinearity of SSMF. We propose to address all of these shortcomings by replacing SSMFs with hollow-core optical fibres, which have simultaneously six times lower chromatic dispersion and several orders of magnitude lower nonlinearity (Brillouin, Kerr). We demonstrate the advantages in this application using a 7.7 km long hollow-core fibre sample, significantly surpassing the performance of an SSMF link in virtually every metric, including 15 dB higher link gain and 6 dB lower noise figure.

关键词： nonlinearity microwave shortcomings

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一种新的有机污染物采样装置

分析化学 2000年第11期28卷 1434-1438页

作者：张勇,林汉华,潘嘉辉,Bruce john richardson,洪华生,郑金树,胡绍燊海洋环境科学教育部重点实验室!厦门大学环境科学研究中心厦门361005 香港城市大学生物和化学系!香港城市大学海岸带污染与保护中心香港九龙香港城市大学生物和化学系!香港城市大学海岸带污染与保护中心香港九龙香港城市大学生物和化学系!香港城市大学海岸带污染与保护中

介绍了一种由类脂物和半透膜组成的采样装置。该装置可模拟生物监测可被生物富集的有机污染物。将其用于监测大气、水体、沉积物中的多氯联苯 (PCBs)、有机氯农药(OCP)和多环芳烃 (PAHs)时 ,结果满意。

关键词：半透膜装置采样有机污染物

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中国寻求倾销规则的改变

化工文摘 2004年第1期 28-29页

作者： john richardson

2001年12月,中美就中国加入世界贸易组织问题达成协议。协议表明美国支持中国加入世界贸易组织,但前提条件是把中国归为'非市场经济'国家,过渡期为15年。也就是说在此期间,美国的反倾销调查在计算涉案产品的'正常价格'时将采取'替代国'... 详细信息

2001年12月,中美就中国加入世界贸易组织问题达成协议。协议表明美国支持中国加入世界贸易组织,但前提条件是把中国归为'非市场经济'国家,过渡期为15年。也就是说在此期间,美国的反倾销调查在计算涉案产品的'正常价格'时将采取'替代国'办法。

关键词：中国倾销规则化工行业美国世界贸易组织市场经济贸易保护

灰暗的阴影——东南亚主要石化生产国经济分析

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化工文摘 2004年第2期 5-6页

作者： john richardson ACN

在今年的头几周，几乎每个人都在专栏上看到对今年经济乐观的各种评论，这些观点认为在全球经济复苏的大背景下，今年将是东南亚经济的好年头。然而事实是不是如此呢?让我们对东南亚几个主要石化产品生产国作一观察。

关键词：东南亚经济分析泰国石化生产国马来西亚新加坡

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亚洲苯的市场走向

化工文摘 2005年第5期 21-22页

作者： john richardson

一些预测认为在今后2～3年苯的供应会严重短缺，但也肓预测会大量过剩。作者对此问题的不确定因素进行了调查研究。

关键词：亚洲苯市场供应法规问题原料问题利润问题

Solar Activity, Solar Wind and Geomagnetic Signatures

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Atmospheric and Climate Sciences 2013年第4期3卷 610-617页

作者： Jean-Louis Zerbo Frédéric Ouattara Christine Amory Mazaudier Jean-Pierre Legrand john D. richardson Ecole Normale Supérieure de l’Université de Koudougou Koudougou Burkina Faso Institut National des Sciences de l’Univers (INSU) Paris France Kavli Institute for Astrophysics and Space Research Massachusetts Institute of Technology Cambridge USA LPP-Laboratoire de Physique des Plasmas/UPMC/Polytechnique/CNRS Saint-Maur-des-Fossés France Université Polytechnique de Bobo-Dioulasso Bobo-Dioulasso Burkina Faso

The present study investigates solar events through geomagnetic activity and physical processes on the Sun: 1) Quiet activity (QA) related to the slow solar wind, 2) Recurrent activity (RA) related to high and moderate speed solar wind streams from coronal holes, 3) Shock activity (SA) identified by observations of SSCs and 4) Unclear activity (UA) which contains all activity not covered by the first three cases. For recent cycles, we analyze and emphasize some important results: Quiet activity is predominant for cycle 23, comprising 40% of the total activity and over 80% of the activity near solar minimum. Shock and recurrent activity contributions to total geomagnetic activity are largest in cycle 20. The most fluctuating events are observed during cycles 21 and 22. Throughout solar cycle 23, the contribution, from each type of activity, differs from recent solar cycles, with larger percentages of quiet and recurrent activity and less unclear activity. These percentages are similar to those in solar cycles observed in the late 1800s. Since 1963, solar wind data are available. We analyze the distribution of the solar wind velocity for each geomagnetic class of activity and find that: 1) Within each activity type aa does not depend on V, 2) Approximately 80% of the solar wind has V 450 km/s for RA, 3) SA and UA both have 60% of the solar wind V > 450 km/s. We found the following conditions for all four solar cycles: 1) For QA 95% of solar wind speeds are in the range 399 ± 69 km/s, 2) For RA 95% of the solar wind speeds range from 582 ± 110 km/s, 3) For SA 95% of the solar wind velocities are order of 482 ± 101.4 km/s, and 4) For UA 95% of solar wind speeds are 480 ± 85.82 km/s. These results confirm the classification scheme that QA reflects slow wind effects, RA effects high wind stream and UA answers to the fluctuations between high wind stream (~60%) and slow wind (~40%). The study shows that high wind stream (

关键词： Solar Wind Geomagnetic Activity Solar Activity Geomagnetic Index aa

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八十年代全球模型的设计

科学与社会 1981年第4期 41-52页

作者： john M.richardson,Jr 顾为群华盛顿哥伦比亚特区美利坚大学国际事务学院

“人们很难不感受到来自全球模型的一些断言的影响。”当罗马俱乐部以《增长的极限》为题的报告描述第一个全球模型的时候,大多数读者就会体验到这一点。从那时开始,在全球模型方面的进展是很多的;较之在这里对一些现行的重要例子提出... 详细信息

“人们很难不感受到来自全球模型的一些断言的影响。”当罗马俱乐部以《增长的极限》为题的报告描述第一个全球模型的时候,大多数读者就会体验到这一点。从那时开始,在全球模型方面的进展是很多的;较之在这里对一些现行的重要例子提出简要的看法来说,要做的事太多了。这些模型可以分成三大类:国际应用系统分析研究所(II ASA)会议模型、经济模型和有政治倾向的模型。作者认为,在构想更加人道、持久和公平的社会前景时,八十年代的全球模型设计,能够起重要的作用。

关键词：模型设计设计师全球模型八十年代

Influence of Bitumen Emulsion Spray on Pavement Performance

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Journal of Traffic and Transportation Engineering 2019年第4期7卷 138-143页

作者： john richardson Connor Campbell Head of Technical Department Colas LimitedWallage LaneCrawleyRH10 4NFUnited Kingdom UK Technical Service Manager Shell International Petroleum Company LimitedRowlandsway HouseManchesterM22 5SBUnited Kingdom

Bitumen emulsion sprays have an important part to play in the achievement of durable,efficient road pavement ***,spraying of bond coats or tack coats at the interface of the bound layers should improve the likelihood of full bond and of resistance to the entry of water through the layers,both of which are needed to meet the design objectives and for the pavement to continue to function *** 594987 recommends bond coats,which are typically polymer modified bitumen emulsion,as best practice and their use is prevalent for the whole range of paved areas in the *** work examines the effect of different rates of spread of bitumen emulsion sprays on interlayer adhesion and permeability,and attempts to ascertain whether there are optimum quantities to obtain the desired effects.

关键词： Bond coat bitumen emulsion road pavement permeability

第一届亚洲翻译研讨会KyotoEBMT系统报告

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情报工程 2017年第3期3卷 47-54页

作者： john richardson Fabien Cromières Toshiaki Nakazawa Sadao Kurohashi 何彦青刘建辉京都大学信息学院科学技术振兴机构中国科学技术信息研究所北京100038 河北地质大学石家庄050031

本文介绍了基于实例的机器翻译引擎KyotoEBMT的框架。为了保留语句的非局部结构,我们的系统运用"树到树"的方法对源语言和目标语言都进行了依存句法分析。我们的系统凭借在线的实例匹配和灵活的解码装置确保其最优的翻译效果。实验表明... 详细信息

本文介绍了基于实例的机器翻译引擎KyotoEBMT的框架。为了保留语句的非局部结构,我们的系统运用"树到树"的方法对源语言和目标语言都进行了依存句法分析。我们的系统凭借在线的实例匹配和灵活的解码装置确保其最优的翻译效果。实验表明:该系统与当前流行的基于短语的统计机器翻译系统的BLEU得分相当。该系统已开源可得。

关键词：实例树到树句法依存分析机器翻译