冲击荷载作用下新型延展式张力腿平台时域分析

延展式张力腿平台是一种适用于深水油气开采的海洋平台结构。提出一种新型平台由四个立柱和一个环形浮箱连接而成,环形浮箱是由四个箱型梁焊接而成。根据给出的南海海域的海况条件和相应的规范计算结构的环境载荷,运用SESAM软件Deep C模块,考虑风、浪、流等环境荷载的作用和张力腿系统的非线性影响,进行了时域耦合分析,得到了平台的运动位移时程、张力腿系统张力时程和张力极值等。模拟波浪破碎作为冲击载荷,得到张力腿平台在冲击荷载作用下的运动位移时程、张力腿系统的张力时程。研究结果表明:该新型平台具有良好的运动响应,张力筋腱应力满足安全要求;在冲击载荷作用下新型平台的运动响应也满足要求。     

南海东北陆缘的地壳速度结构及其构造意义: 来自广角地震剖面的约束

南海东北部深部地壳结构蕴含着南海陆缘伸展张裂过程的重要信息。在南海东北陆缘布设的一条广角地震测线(DP13)沿NW-SE方向依次穿过东沙隆起和台西南盆地。本文利用射线追踪和正演走时拟合软件RayInvr构建地壳纵波速度结构,模型表明：沉积层速度1.6～4.6 km/s,厚度0.5～3.8 km,横向分布不均匀,沉积基底起伏剧烈;莫霍面埋藏深度由陆架区的25.5 km急剧减小到陆坡下方的13 km,随后向下陆坡远端增深至16 km;陆架处东沙隆起下方地壳厚度从～25 km减薄到～21 km,下陆坡远端地壳厚约10～13 km,地壳拉张因子分别为1.3～1.5和2.6～3.1,表现为轻微和中等减薄;陆坡区台西南盆地内地壳厚度从17 km急剧减薄至7～8 km,地壳拉张因子高达4.6,呈超伸展减薄;地壳厚度由陆向海非单调减薄,地壳伸展具有明显的空间差异性;陆架-上陆坡和下陆坡下地壳底部发现两个相对孤立的不连续高速体,速度分别为7.0～7.5 km/s和7.0～7.3 km/s,厚度分别3～5 km和1～3 km,前者位于古太平洋俯冲带前缘,几乎与南海东北部高磁异常重叠,推测由中生代古太平洋板...     

南阿尔金地区早古生代中酸性侵入岩的岩石成因及其对构造演化的指示意义

南阿尔金造山带位于塔里木盆地和柴达木盆地之间,是中国西北地区重要的俯冲-碰撞杂岩带,其早古生代构造演化过程是近年来的研究热点之一,然而,洋壳俯冲的时限一直存在争议。本文对茫崖石英二长岩开展岩石学、地球化学、锆石U-Pb年代学和锆石Lu-Hf同位素地球化学研究,探讨其岩石成因及成岩时的构造环境。样品显示高碱、富钾、低钛、贫铁及Nd-Ta-Ti异常等与钾玄岩相似的地球化学特征,成岩年龄为511～495 Ma, ε_Hf(t)主要为-3.51～-0.08,少量介于0.04～1.69之间。我们认为俯冲洋壳到达角闪岩相边界时释放大量水并上升进入地幔楔,导致地幔楔橄榄岩发生角闪石化交代作用,由于地幔楔沿俯冲带向下拖曳而温度升高,角闪石化橄榄岩熔融形成的熔体在上升过程诱发上地壳物质部分熔融,壳源岩浆混合少量幔源岩浆形成了石英二长岩,该期花岗岩是对造山带从大洋岛弧环境向活动大陆边缘过渡的岩石学响应。因此,南阿尔金洋壳可能在约517 Ma前已经开始俯冲。     

Lower and Middle Ordovician conodonts of Laurentian affinity from blocks of limestone in the Rosroe Formation,South Mayo Trough,western Ireland and their palaeogeographic implication

The Middle Ordovician Rosroe Formation consists of some 1350 m of coarse, mainly siliciclastic to volcaniclastic sedimentary rocks, deposited in a submarine fan environment, and is restricted to the southern limb of the South Mayo Trough, western Ireland. Discrete allochthonous blocks, reaching 5 m in size, are present in the formation at several localities. Conodonts recovered from these blocks, collected from two separate locations, are of late Early and mid Mid Ordovician age. The conodonts have high conodont‐alteration indices (CAI 5) indicative of temperatures as high as 300^o to max. 480 °C; some found in the Lough Nafooey area have abnormally high indices (CAI 6), which correspond to temperatures of about 360^o to max. 550 °C. The oldest fauna is dominated by Periodon aff. aculeatus and characterized by Oepikodus evae typical of the Oepikodus evae Zone (Floian Stage; Stage Slices Fl2–3, Lower Ordovician). The younger conodont assemblage, characterized by Periodon macrodentatus associated with Oistodella pulchra, is referred to the P. macrodentatus conodont Biozone (lower Darriwilian; Stage Slices Dw1–2). The Rosroe conodont assemblages are of Laurentian affinity; comparable faunas are well known from several locations along the east to south‐eastern platform margin of Laurentia and the Notre Dame subzone of central Newfoundland, Canada. The faunal composition from the limestone blocks suggests a shelf edge to slope (or fringing carbonate) setting. The faunal assemblages are coeval with, respectively, the Tourmakeady Formation (Floian–Dapingian) and Srah Formation (Darriwilian) in the Tourmakeady Volcanic Group in the eastern part of the South Mayo Trough and probably are derived from the same or similar laterally equivalent short‐lived carbonate successions that accumulated at offshore ‘peri‐Laurentian’ islands, close to and along the Laurentian margin. During collapse of the carbonate system in the late Mid Ordovician, the blocks were transported down a steep slope and into deep‐water by debris flows, mixing with other rock types now found in the coarse polymict clastics of the Rosroe Formation. The faunas fill the stratigraphical ‘gap’ between the Lower Ordovician Lough Nafooey Volcanic Group and the upper Middle Ordovician Rosroe Formation in the South Mayo Trough and represent a brief interval conducive to carbonate accumulation in an otherwise siliciclastic‐ and volcaniclastic‐dominated sedimentary environment. Copyright © 2015 John Wiley & Sons, Ltd.     

冬季西太平洋暖池与华南降水关系的年代际变化

利用1951-2010年全国台站冬季降水观测资料、Hadley环流中心逐月海表温度资料以及NCEP/NCAR再分析月平均资料,探讨了西太平洋暖池与我国华南地区冬季降水的关系。结果表明,西太平洋暖池与我国华南冬季降水的年际关系在1972年发生了明显的年代际转折,20世纪70年代前两者弱的负相关未通过信度检验,而70年代后两者相关系数达到-0.5~-0.6。回归分析显示,70年代前,暖池对产生华南冬季降水的水汽条件以及动力条件等的影响不显著,因此其与华南冬季降水的关系不明显。70年代后,暖池偏暖时,在菲律宾海区域激发出一个显著的气旋性环流,该环流西北侧的偏北风不利于南海地区水汽向我国华南地区输送,华南地区水汽辐散增强,而且南支槽地区对流减弱,南支扰动不活跃且扰动不能向下游地区传播,华南地区扰动活动减弱,此外暖池偏暖使北半球经向环流显著增强,且下沉支位于我国华南地区,加强了华南地区的下沉运动,因而华南地区冬季降水显著偏少;暖池偏冷时,情况相反。     

基于海温异常的南海夏季风爆发的可预报性分析

定义了综合评估南海地区大气对海温异常等外强迫响应的指数,并以此作为中间变量提出了利用前期海温异常预报南海夏季风爆发早晚的方法,进一步分析了基于海温异常的南海夏季风爆发的可预报性。分析表明:基于前期海温的异常,对于以日为单位预报对象的定量的南海夏季风爆发日期来说,基本没有可预报性;而对于定性的南海夏季风爆发早晚的预测,则可预报性大为提高。其预报时效可以提前至前期秋季的11月份。     

Innovation for sustainable energy from a pro-poor perspective

The development and transfer of clean energy technologies to achieve universal energy access is challenging due to the inherent complexities of the energy sector, and the energy governance and financial systems in developing economies. Innovation is an essential part of successfully addressing these difficulties. Duplicating the energy infrastructure models of developed countries will not be sufficient to meet the needs of poor consumers. To the extent that innovation can accelerate energy access, it is important to understand the specific types of innovations that are necessary and how they might be facilitated. The general features of existing international clean energy innovation systems, which are predominantly driven by the markets and emissions reduction mechanisms of developed and rapidly growing emerging economies, are reviewed and the alignment of these systems to the innovation processes required to extend energy access globally is evaluated. Drawing on the innovation policy literature, the attributes of effective international and domestic energy innovation systems that are pro-poor and the associated policy approaches are identified.     

Seasonal prediction of June rainfall over South China: Model assessment and statistical downscaling

The performances of various dynamical models from the Asia-Pacific Economic Cooperation(APEC) Climate Center(APCC) multi-model ensemble(MME) in predicting station-scale rainfall in South China(SC) in June were evaluated.It was found that the MME mean of model hindcasts can skillfully predict the June rainfall anomaly averaged over the SC domain.This could be related to the MME's ability in capturing the observed linkages between SC rainfall and atmospheric large-scale circulation anomalies in the Indo-Pacific region.Further assessment of station-scale June rainfall prediction based on direct model output(DMO) over 97 stations in SC revealed that the MME mean outperforms each individual model.However,poor prediction abilities in some in-land and southeastern SC stations are apparent in the MME mean and in a number of models.In order to improve the performance at those stations with poor DMO prediction skill,a station-based statistical downscaling scheme was constructed and applied to the individual and MME mean hindcast runs.For several models,this scheme can outperform DMO at more than 30 stations,because it can tap into the abilities of the models in capturing the anomalous Indo-Paciric circulation to which SC rainfall is considerably sensitive.Therefore,enhanced rainfall prediction abilities in these models should make them more useful for disaster preparedness and mitigation purposes.     

Preliminary observations of the internal tide over the shelf west of New Zealand

Abstract

Semidiurnal variations in the depth of the thermocline observed near the shelf edge north‐west of Cape Egmont are probably caused bv an internal tide generated at around 200 m depth over the continental slope. The observations suggest that in this region an internal tide, with amplitude of about 20 m, propagates onto the shelf with a speed of approximately 0.5 m·s^?1 and a wavelength of about 22 km.     

Hydrolytic enzymes of the paua Haliotis iris,a marine gastropod (note).

Extracts of the viscera of Haliotis iris (Martyn, 1784) were shown to hydrolyse 2‐hydroxy‐5‐nitrophenyl sulphate at pH 5.5, and the p‐nitrophenyl derivatives of α‐ and β‐D‐galactose, α‐ and β‐D‐mannose, α‐L‐lucose, β‐D‐glucuronic acid, β‐N‐acetyl glucosamine and phosphate at pH 4.0 and 5.5: p‐nitrophenyl‐β‐L‐fucose was not hydrolysed.