Effect of copper on fertilization success in the reef coral Acropora surculosa     

Victor S  Richmond RH 《Marine pollution bulletin》2005,50(11):1448-1451

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Effects of the MV Rena oil spill on intertidal rocky reefs in the Bay of Plenty,New Zealand     

DR Schiel  PM South  SA Lilley 《新西兰海洋与淡水研究杂志》2016,50(1):70-86

In the weeks following the 2011 Rena oil spill, a series of surveys was initiated on eight rocky intertidal reefs to describe the distribution of oil and to assess the impacts of oil on ecological communities. Consistent but relatively low cover of oil occurred at two sites (Mt Maunganui and Moturiki). The area covered by oil had decreased by c. 90% after 5 months due to natural weathering processes. There were immediate effects of oil fouling on the mussel Limnoperna pulex and its associated fauna, with reductions in the number of mussels and infaunal taxonomic richness. However, no ecological effects on any of the communities were detectable after 1 month. Overall, the ecological effects of the Rena oil spill on rocky shore intertidal communities were small and not long-lasting, but we stress that this does not consider potential sublethal effects and their consequences on organisms.  相似文献   

The Cawthron Institute Culture Collection of Micro-algae: a significant national collection     

L Rhodes  KF Smith  L MacKenzie  SA Wood  K Ponikla  DT Harwood 《新西兰海洋与淡水研究杂志》2016,50(2):291-316

The Cawthron Institute Culture Collection of Micro-algae (CICCM) is a unique, nationally and internationally significant collection of 450 strains of approximately 100 micro-algae and 50 cyanobacteria species, both living and cryopreserved. The collection comprises 13 taxonomic classes and underpins research into the ecology and taxonomy of the isolates and the biotoxins they produce and their toxicity. The CICCM expanded significantly in the 1990s after a major harmful algae bloom event in the Hauraki Gulf, New Zealand. Since 2000, it has underpinned development of molecular detection tools and enabled development of new chemical testing methods for biotoxins in seafood. The tropical collection allows research into potential issues for New Zealand as the oceans warm, for example, the risks of ciguatera fish poisoning and palytoxins in seafood. Research results generated from isolates in the cyanobacterial collection have assisted national risk management regarding drinking water and informed the development of the New Zealand guidelines for managing cyanobacteria in recreational fresh waters. The actual living and cryopreserved micro-algae and cyanobacteria collection (without infrastructure) has a current estimated value of NZ$1.6 million.  相似文献   

巷道围岩状态的等效应力等效应变表述     

潘岳  撒占友  贺可强 《岩土力学》2005,26(11):1695-1699

在体积应变为零的条件下,根据巷道围岩属简单加载的特性得到围岩中同时关联三向应力 , , 和三向应变 , , 的,用等效应力 和等效应变 表示的对围岩加载-形变关系式。严格地论证了巷道围岩的弹性、硬化、软化和流动区的应力应变状态分别与围岩的等效应力-等效应变曲线各阶段的应力应变状态相对应。以等效应力、等效应变为中间变量可以简化围岩弹性分析,简捷地写出巷道围岩偏应力应变能的计算公式。等效剪应力 是围岩中的最大剪应力 ,等效剪应力单元受正应力和剪应力作用,但其上只有剪切应变,这突出了巷道围岩形变破坏是由于最大剪应力和偏应力应变能所致的实质。根据等效剪应力概念确定的滑移线,可适用于材料应变硬化和软化阶段,不要求刚塑性假定条件。  相似文献   

2015—2020年中国土地利用变化遥感制图及时空特征分析   总被引：1，自引：0，他引：1  

匡文慧  张树文  杜国明  颜长珍  吴世新  李仁东  陆灯盛  潘涛  宁静  郭长庆  董金玮  包玉海  迟文峰  窦银银  侯亚丽  尹哲睿  常丽萍  杨久春  谢家丽  邱娟  张汉松  张宇博  杨仕琪  萨日盖  刘纪远 《地理学报》2022,77(5):1056-1071

持续地开展国家尺度土地利用/覆盖变化遥感监测对于新时代国土空间规划和“美丽中国”蓝图绘制具有重要的科学价值。本文采用Landsat 8 OLI、GF-2等卫星遥感数据,融合遥感大数据云计算和专家知识辅助人机交互解译方法,研发了中国土地利用变化（2015—2020年）和2020年土地利用现状矢量数据（CLUD 2020）,建立了完整的30 a（20世纪80年代末—2020年）每隔5 a的30 m分辨率中国土地利用动态数据库。基于CLUD 2020数据,从全国和区域两个尺度揭示了2015—2020年中国土地利用变化的总体规律、区域分异和主要特征。研究表明：将遥感大数据云计算生成的30 m分辨率植被覆盖变化和地表类型变化检测信息融入到人机交互遥感解译方法,可有效地提高大范围土地利用变化遥感制图的效率和变化图斑辨识的准确性;精度评价表明,CLUD 2020一级类型制图的综合精度达95%。总体上,全国范围内国土空间开发强度与2010—2015年比较进入相对稳定状态。期间全国耕地面积仍保持减少态势,空间分异特征为耕地南减北增,东北松嫩平原及其与三江平原交界区大规模的旱地向水田转移,西北新疆南部开垦和北部退耕/撂荒并存;全国城乡建设用地持续增加,空间分异特征表现为由以往的沿海地区和超大、大城市集聚转向中西部地区的大中小城镇周边蔓延为主。全国范围的林草自然生态用地面积持续减少,但强度与2010—2015年比较有所下降;受气候变化的持续影响,青藏高原地区的河流湖泊等水域面积显著增加。以上土地利用变化格局与“十三五”期间国家高质量发展、生态文明建设宏观战略和气候变化的影响密切相关。  相似文献   

近10年新疆积雪面积时空变化研究   总被引：1，自引：0，他引：1  

萨楚拉  刘桂香  包刚  包玉海  王牧兰  道日那 《测绘科学》2013,38(1):72-74

区域尺度积雪信息的时空监测对确定雪灾的影响范围及灾情等级划分具有重要意义。本文利用近10年的MODIS积雪产品,按月最大面积的规则合成;分析了新疆积雪覆盖面积的时空变化特征,结果表明:时间上,新疆积雪面积有减少的趋势。空间上,近10年新疆积雪季节内永久性积雪覆盖区域主要分布在阿勒泰山脉、天山北麓及沿昆仑山脉西南部。其中天山及阿尔泰山之间的河谷及盆地的草原积雪面积波动主导了新疆整体积雪总面积的波动。  相似文献   

更新世冰盖与大洋碳储库相互作用的箱式模型模拟     

马文涛  田军  李前裕 《地球科学》2011,36(4):621-634

全球大洋深海有孔虫碳同位素(δ13C)记录中广泛发现40万年周期,这一周期可能与偏心率长周期的轨道驱动有关.1.6 Ma以来,δ13C的这一长周期拉长到50万年,且重值期不再与偏心率低值对应.目前对δ13C 40万年周期的成因及其周期拉长的机制还不明确.这里使用了包含9个箱体的箱式模型,用于研究热带过程与冰盖相互作用及其对大洋碳循环的影响.模拟结果显示当北半球高纬海区海冰迅速增大时冰盖迅速融化,进入冰消期,而当海冰快速消失后,冰盖则重新缓慢增长.冰盖变化具有冰期长,间冰期短的非对称形态.在季节性太阳辐射量的驱动下冰盖变化具有10万年冰期-间冰期旋回.当冰盖融化速率受北半球高纬夏季太阳辐射量控制时,冰盖变化的岁差周期明显加强,相位与地质记录一致,说明轨道驱动可以通过非线性相位锁定机制使冰盖变化与其在相位上保持一致.海冰的阻隔效应使大气中CO₂在冰消期时增多.冰期时大洋环流减弱使大气中CO₂逐渐减少.当模型只有ETP驱动的风化作用而不考虑冰盖变化时,模拟的δ13C记录显示极强的40万年周期,体现了大洋碳储库对热带风化过程的响应.当同时考虑冰盖变化和风化作用时,模拟的δ13C结果中40万年周期减弱而10万年周期加强,并且40万年周期上碳储库与偏心率的相位与不考虑冰盖变化时的相位也存在差异,反映了冰盖变化引起的洋流改组压制了大洋碳循环对热带过程的响应.   相似文献   

SN 2005cs in M51 – II. Complete evolution in the optical and the near-infrared     

A. Pastorello  S. Valenti  L. Zampieri  H. Navasardyan  S. Taubenberger  S. J. Smartt  A. A. Arkharov  O. Bärnbantner  H. Barwig  S. Benetti  P. Birtwhistle  M. T. Botticella  E. Cappellaro  M. Del Principe  F. Di Mille  G. Di Rico  M. Dolci  N. Elias-Rosa  N. V. Efimova  M. Fiedler  A. Harutyunyan  P. A. Höflich  W. Kloehr  V. M. Larionov  V. Lorenzi  J. R. Maund  N. Napoleone  M. Ragni  M. Richmond  C. Ries  S. Spiro  S. Temporin  M. Turatto  J. C. Wheeler 《Monthly notices of the Royal Astronomical Society》2009,394(4):2266-2282

We present the results of the one-year long observational campaign of the type II plateau SN 2005cs, which exploded in the nearby spiral galaxy M51 (the Whirlpool galaxy). This extensive data set makes SN 2005cs the best observed low-luminosity, ⁵⁶Ni-poor type II plateau event so far and one of the best core-collapse supernovae ever. The optical and near-infrared spectra show narrow P-Cygni lines characteristic of this SN family, which are indicative of a very low expansion velocity (about  1000 km s⁻¹  ) of the ejected material. The optical light curves cover both the plateau phase and the late-time radioactive tail, until about 380 d after core-collapse. Numerous unfiltered observations obtained by amateur astronomers give us the rare opportunity to monitor the fast rise to maximum light, lasting about 2 d. In addition to optical observations, we also present near-infrared light curves that (together with already published ultraviolet observations) allow us to construct for the first time a reliable bolometric light curve for an object of this class. Finally, comparing the observed data with those derived from a semi-analytic model, we infer for SN 2005cs a ⁵⁶Ni mass of about  3 × 10⁻³ M_⊙  , a total ejected mass of  8–13 M_⊙  and an explosion energy of about  3 × 10⁵⁰ erg  .  相似文献   

Geology,palynology, and climatic significance of two pre-Pinedale Lake sediment sequences in and near Yellowstone National Park     

Richard G. Baker  Gerald M. Richmond 《Quaternary Research》1978,10(2):226-240

Pollen analysis of a section of lake sediments at Grassy Lake Reservoir indicates a vegetational sequence changing from tundra, to spruce-fir-pine forest, to pine forest, to tundra at the top. Pollen analysis of a section of lake sediments on Beaverdam Creek indicates a tundra vegetation at the base, followed by a brief episode of spruce-fir forest and a return to a tundra vegetation at the top. The analyses of both sections suggest a cold to cool to cold climatic sequence, interpreted as interstadial in character. However, differences suggest that they represent separate interstadials. Pinedale Till disconformably overlies the lake deposits at Grassy Lake Reservoir. The upper sediments contain wood ¹⁴C dated at >42,000 yr; the lowermost interfinger with till shown to be more than about 70,000 yr old. The deposits at Beaverdam Creek grade upward into proglacial Pinedale deposits, contain an ash that is probably about 70,000 yr old near their base, and rest comformably on gravel that grades down into lake sediments containing wood debris suggestive of an older climatic amelioration. We conclude that the warmest part of the interstadial at Grassy Lake Reservoir is probably more than 70,000 yr old, and that the warmest part of the interstadial analyzed at Beaverdam Creek is slightly younger than 70,000 yr old.  相似文献   

Financially Efficient Ore Selections Incorporating Grade Uncertainty     

Andrew Richmond 《Mathematical Geology》2003,35(2):195-215

Traditional mining selection methods focus on local estimates or loss functions that do not take into account the potential diversification benefits of financial risk that is unique to each location. A constrained efficient set model with a downside risk function is formulated as a solution. Estimates of this nonlinear mixed-integer combinatorial optimization problem are provided by a simulated annealing heuristic. A utility framework that is congruent with the proposed efficiency model is then used to choose the optimal set of local mining selections for a decision-maker with specific risk-averse characteristics. The methodology is demonstrated in a grade control environment. The results show that downside financial risk can be reduced by around 33% while the expected payoff is only reduced by 1% when compared to ore selections generated by traditional cut-off grade techniques.  相似文献