950 resultados para Lawson, James, 1799-1880.
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Demographic parameters were derived from sectioned otoliths of John’s Snapper (Lutjanus johnii) from 4 regions across 9° of latitude and 23° of longitude in northern Australia. Latitudinal variation in size and growth rates of this species greatly exceeded longitudinal variation. Populations of John’s Snapper farthest from the equator had the largest body sizes, in line with James’s rule, and the fastest growth rates, contrary to the temperature-size rule for ectotherms. A maximum age of 28.6 years, nearly 3 times previous estimates, was recorded and the largest individual was 990 mm in fork length. Females grew to a larger mean asymptotic fork length (L∞) than did males, a finding consistent with functional gonochorism. Otolith weight at age and gonad weight at length followed the same latitudinal trends seen in length at age. Length at maturity was ~72–87% of L∞ and varied by ~23% across the full latitudinal gradient, but age at first maturity was consistently in the range of 6–10 years, indicating that basic growth trajectories were similar across vastly different environments. We discuss both the need for complementary reproductive data in age-based studies and the insights gained from experiments where the concept of oxygen- and capacity-limited thermal tolerance is applied to explain the mechanistic causes of James’s rule in tropical fish species.
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Historical sources of the late-18th and 19th centuries were searched for information on coastal weather conditions in Southern California. Relatively calm winters until 1828 were followed by unusually stormy winters from about 1829 to 1839. Later periods were again predominantly calm, with notable exceptions related to the ENSO events of 1845 and 1878. Following decreases through the stormy 1830s, sizes of kelp forests appear to have rebounded in the 1840s. ENSO occurrences and eruption of the volcano Cosiguina in 1835 are likely causes for changing wind patterns. Our results link the unique AD 1840 Macoma leptonoidea pelecypod shell layer in laminated Santa Barbara Basin sediment ("Macoma event") to abruptly changing oceanographic and weather patterns.
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Following a tunnel excavation in low-permeability soil, it is commonly observed that the ground surface continues to settle and ground loading on the tunnel lining changes, as the pore pressures in the ground approach a new equilibrium condition. The monitored ground response following the tunnelling under St James's Park, London, shows that the mechanism of subsurface deformation is composed of three different zones: swelling, consolidation and rigid body movement. The swelling took place in a confined zone above the tunnel crown, extending vertically to approximately 5 m above it. On the sides of the tunnel, the consolidation of the soil occurred in the zone primarily within the tunnel horizon, from the shoulder to just beneath the invert, and extending laterally to a large offset from the tunnel centreline. Above these swelling and consolidation zones the soil moved downward as a rigid body. In this study, soil-fluid coupled three-dimensional finite element analyses were performed to simulate the mechanism of long-term ground response monitored at St James's Park. An advanced critical state soil model, which can simulate the behaviour of London Clay in both drained and undrained conditions, was adopted for the analyses. The analysis results are discussed and compared with the field monitoring data. It is found that the observed mechanism of long-term subsurface ground and tunnel lining response at St James's Park can be simulated accurately only when stiffness anisotropy, the variation of permeability between different units within the London Clay and non-uniform drainage conditions for the tunnel lining are considered. This has important implications for future prediction of the long-term behaviour of tunnels in clays.
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The twin-tunnel construction of the Jubilee Line Extension tunnels beneath St James's Park was simulated using coupled-consolidation finite-element analyses. The effect of defining different permeabilities for the final consolidation stage was investigated, and the performance of a fissure softening model was also evaluated. The analyses suggested an unexpectedly high permeability anisotropy for soil around the tunnel crown, possibly due to stress-induced permeability changes, or low-permeability laminations. Also, the permeability profile and lining conductivity were found to differ between the tunnels. Inclusion of the fissure model gave a narrower settlement trough, more alike that in the field, by preferentially softening simple shear behaviour. Long-term settlements at the site continue to increase at an unexpectedly high rate, suggesting the possibility of creep or unexpected soil softening during excavation. © 2012 Taylor & Francis Group.
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本文对崔—Lawson模型与logistic方程进行了比较,指出了以营养动力学为基础的崔—Lawson模型关于生物物种与营养环境之间关系的内涵思想,从而揭示了崔—Lawson模型比logistic方程之所以深刻的关键所在。本文通过对棕色固氮菌的菌体培养实验,系统地验证了以营养动力学为基础的崔—Lawson模型思想,并且对实验数据分别进行了崔—Lawson模型及logistic方程拟合。对两个模型拟合出的残差平方和进行了比较。证实崔—Lawson模型比logistic方程更适合于对实验资料的描述。并且随着营养水平逐渐降低,logistic方程拟合的残差平方和逐渐减小,从而说明只有在营养水平低的情况下,才适合用logistic方程,而通常情况下,用logistic方程是不合适的。
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由于森林资源在提供生产/生活资料和维持整个生物圈平衡中的重要作用。森林资源管理在可更新资源管理中地位举足轻重。本文以营养动力学的基本观点和崔-Lawson模型为基础。将森林的收获过程看成是一个调节营养条件的过程。借助最优控制等方法。研究了单种群森林资源的管理策略和理论。1、评价了目前森林(生物)资源经营管理的若干主要原则。指出统一认定的资源管理原则是不存在的。人们对众原则的取舍将根据需要而定。2、根据MSY原则,着重研究了收获强度与收获量之间的关系。得到了连续收获过程的最优收获策略。同时,建立了间断收获过程的数学模型。3、以日本落叶松(Larix leptolepis)人工林为例进行了实例分析。得到了日本落叶松林最优收获策略并分析了日本落叶松种群灭绝时间与收获强度u_(max)之间的关系。
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2002
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Thurston, L. (2004). James Joyce and the Problem of Psychoanalysis. Cambridge: Cambridge University Press. RAE2008
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Williams, Ioan, Y Mudiad Drama yng Nghymru 1880-1940 (University of Wales Press, 2006), pp.vii+215
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Jones, Aled, 'Welsh Missionary Journalism in India, 1880-1947', In: 'Imperial Co-Histories: National Identities and the British and Colonial Press', (Cranbury, NJ: Fairleigh Dickinson University Press), pp.242-272, 2003 RAE2008
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Roberts, Owen, 'Waterworks and commemoration: purity, rurality, and civic identity in Britain, 1880-1921', Continuity and Change (2007) 22(2) pp.305-325 RAE2008
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Recenzje i sprawozdania z książek
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