A Bragg-mirror-based semiconductor saturable absorption mirror at 800 nm with low temperature and surface state hybrid absorber

We present a novel 800-nm Bragg-mirror-based semiconductor saturable absorption mirror with low temperature and surface state hybrid absorber, with which we can realize the passive soliton mode locking of a Ti:sapphire laser pumped by 532-nm green laser which produces pulses as short as 37 fs. The reflection bandwidth of the mirror is 30 nm and the pulse frequency is 107 MHz. The average output power is 1.1 W at the pump power of 7.6 W.

Study of intensity-dependent nonlinear optical coefficients of GaP optical crystal at 800 nm by femtosecond pump-probe experiment

The intensity-dependent two-photon absorption and nonlinear refraction coefficients of GaP optical crystal at 800 nm were measured with time-resolved femtosecond pump-probe technique. A nonlinear refraction coefficient of 1.7*10^(-17) m2/W and a two-photon absorption coefficient of 1.5*10^(-12) m/W of GaP crystal were obtained at a pump intensity of 3.5*10^(12) W/m2. The nonlinear refraction coefficient saturates at 3.5*10^(12) W/m2, while the two-photon absorption coefficient keeps linear increase at 6*10^(12) W/m2. Furthermore, fifth-order nonlinear refraction of the GaP optical crystal was revealed to occur above pump intensity of 3.5*10^(12) W/m2.

新型HIRFL-800低温泵的设计及热负荷的计算

介绍了近代物理研究所自行研制的新型HIRFL 80 0低温泵。对其抽速、低温冷凝板和屏蔽板的热负荷进行了具体的分析和计算。肯定了新型HIRFL 80 0低温泵的设计方案

HIRFL前束线真空系统的改造与HIRFL-800低温泵的设计及热负荷的计算

本论文首先介绍真空技术涉及的物理基础和真空获得的有关知识，然后讲述，了H_RFL（兰州重离子加速器研究装置）真空系统的基本概况，在此基础上阐述了本论文主要的两部分：H_RFL前束线真空系统的改造；新型H_RFL佩800低温泵的设计一及热负荷的计算。其中H工RF［前束线真空系统的改造已经于2001年9月份完成并为兰州重离子加速器的正常运行提供了必要的真空条件。新型111佩又FL佩800低温泵正在加工生产中，并将用于大型超高真空系统H工R凡厂SSC（兰州重离子加速器研究装置主加速器）的抽空。H工RFL前束线真空系统的改造介绍了兰州重离子加速器前束线真空系统的基本结构，详细说明了H工RFL前束线真空系统改造前的流导、气体负荷及压力分布情况。提出了具体的改造措施。真空系统达到了预计要求：泵口压强小于5只10-6Pa，两泵之间束运管道中心平面压强小于1x10-5Pa.结果表明H工RFL前束线真空系统的改造方案是有效的。新型HIRFL一800低温泵的设计及热负荷的计算介绍了近代物理研究所自行研制的新型H工RFL一800低温泵。对其抽速，低温冷凝板和屏蔽板的热负荷进行了具体的分析和计算。肯定了新型H工RFL佩800低温泵的设计方案。

Performance, transmission and devotion: understanding the Anglo-Saxon prayer books, c.800-1050

Through an investigation of the Anglo-Saxon prayer books and selected psalters, this thesis corrects standard histories of medieval devotion that circumvent the Anglo-Saxon contribution to medieval piety. In the first half of the thesis, I establish a theoretical framework for Anglo-Saxon piety in which to explore the prayers. Current theoretical frameworks dealing with the medieval devotional material are flawed as scholars use terms such as ‘affective piety’, ‘private’ and even ‘devotion’ vaguely. After an introduction which defines some of the core terminology, Chapter 2 introduces the principal witnesses to the Anglo-Saxon prayer tradition. These include the prodigal eighth- and early ninth- century Mercian Group, comprising the Book of Nunnaminster (London, British Library, Harley 2965, s. viii ex/ix1), the Harleian Prayer Book (London, British Library, Harley 7653, s. viii ex/ix1), the Royal Prayer Book (London, British Library, Royal 2 A. xx, s. viii2/ix1/4), and the Book of Cerne (Cambridge, University Library, Ll. 1. 10). These prayer books are the earliest of their kind in Europe. This chapter challenges some established views concerning the prayer books, including purported Irish influence on their composition and the probability of female ownership. Chapter 3 explores the performance of prayer. The chapter demonstrates that Anglo-Saxon prayers, for example, the Royal Abecedarian Prayer, were transmitted fluidly. The complex relationship between this abecedarian prayer and its reflex in the Book of Nunnaminster reveals the complexity of prayer composition and transmission in the early medieval world but more importantly, it helps scholars theorise how the prayers may have been used, whether recited verbatim or used for extemporalisation. Changes made by later readers to earlier texts are also vital to this study, since they help answer questions of usage and show the evolution and subsequent influence of Anglo-Saxon religiosity. The second half of the thesis makes a special study of prayers to the Cross, the wounded Christ, and the Virgin, three important themes in later medieval spirituality. These focus on the Royal Abecedarian Prayer, which explores Christ’s life (Chapter 5), especially his Passion; the ‘Domine Ihesu Christe, adoro te cruce’ which celebrates the Cross (Chapter 4); and the Oratio Alchfriðo ad sanctam Mariam, which invokes the Virgin Mary (Chapter 6). These prayers occur in multiple, temporally-diverse witnesses and have complex transmission histories, involving both oral and written dissemination. The concluding chapter (7) highlights some of the avenues for future research opened by the thesis.

A biological consequence of reducing Arctic ice cover: arrival of the Pacific diatom Neodenticula seminae in the North Atlantic for the first time in 800,000 years

The Continuous Plankton Recorder survey has monitored plankton in the Northwest Atlantic at monthly intervals since 1962, with an interegnum between 1978 and 1990. In May 1999, large numbers of the Pacific diatom Neodenticula seminae were found in Continuous Plankton Recorder (CPR) samples in the Labrador Sea as the first record in the North Atlantic for more than 800 000 years. The event coincided with modifications in Arctic hydrography and circulation, increased flows of Pacific water into the Northwest Atlantic and in the previous year the exceptional occurrence of extensive ice-free water to the North of Canada. These observations indicate that N. seminae was carried in a pulse of Pacific water in 1998/early 1999 via the Canadian Arctic Archipelago and/or Fram Strait. The species occurred previously in the North Atlantic during the Pleistocene from similar to 1.2 to similar to 0.8 Ma as recorded in deep sea sediment cores. The reappearance of N. seminae in the North Atlantic is an indicator of the scale and speed of changes that are taking place in the Arctic and North Atlantic oceans as a consequence of regional climate warming. Because of the unusual nature of the event it appears that a threshold has been passed, marking a change in the circulation between the North Pacific and North Atlantic Oceans via the Arctic. Trans-Arctic migrations from the Pacific into the Atlantic are likely to occur increasingly over the next 100 years as Arctic ice continues to melt affecting Atlantic biodiversity and the biological pump with consequent feedbacks to the carbon cycle.

School entry age outcomes for infants with birth weight ≤ 800 grams

To evaluate the mortality and long-term morbidity rates of extremely low birth weight (ELBW) infants admitted to neonatal intensive care units (NICUs).

Psychosocial and academic characteristics of extremely low birth weight (<or =800 g) adolescents who are free of major impairment compared with term-born control subjects

To compare academic and cognitive ability, attention, attitudes, and behavior of extremely low birth weight (ELBW) adolescents who are free of major impairments at 17 years of age with term-born control subjects.

Extremely premature (<or = 800 g) schoolchildren:multiple areas of hidden disability

To examine the functional abilities of extremely low birthweight (ELBW, <or = 800 g) children at school age compared with full term children.

The Value of Full Scale Prototype Data - Testing Oyster 800 at EMEC, Orkney

This paper demonstrates the unparalleled value of full scale data which has been acquired from ocean trials of Aquamarine Power’s Oyster 800 Wave Energy Converter (WEC) at the European Marine Energy Centre (EMEC), Orkney, Scotland.
High quality prototype and wave data were simultaneously recorded in over 750 distinct sea states (comprising different wave height, wave period and tidal height combinations) and include periods of operation where the hydraulic Power Take-Off (PTO) system was both pressurised (damped operation) and de-pressurised (undamped operation).
A detailed model-prototype correlation procedure is presented where the full scale prototype behaviour is compared to predictions from both experimental and numerical modelling techniques via a high temporal resolution wave-by-wave reconstruction. This unquestionably provides the definitive verification of the capabilities of such research techniques and facilitates a robust and meaningful uncertainty analysis to be performed on their outputs.
The importance of a good data capture methodology, both in terms of handling and accuracy is also presented. The techniques and procedures implemented by Aquamarine Power for real-time data management are discussed, including lessons learned on the instrumentation and infrastructure required to collect high-value data.

Comportamiento de las redes de arrastre pelágicas tipo japonés 124/1800 y 216/800. Crucero BIC Olaya Balandra 9805-06 de Los Palos (Tacna) a Máncora (Piura)

Presenta los resultados del comportamiento de las redes de arrastre pelágicas tipo japonés 124/1800 y 216/800 utilizada en la toma de muestras en la estimación del stock de recursos pelágicos: anchoveta, sardina, jurel, caballa y samasa durante el crucero hidroacústico 9805-06 a bordo del BIC José Olaya Balandra.