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91.
Coral reefs and other coastal ecosystems such as seagrasses and mangroves are widely recognized to provide protection against the devastating effects of strong waves associated with tsunamis and storms. The predicted warming climate brings to fore the role of these ecosystems in providing protection against stronger typhoons that can result in more devastating waves of greater amplitude. We performed a model simulation of storm generated waves on a Philippine reef, which is located along the path of tropical storms, i.e., at least 10 typhoons on the average pass through the study site yearly. A model to simulate wave propagation was developed using Simulating Waves Nearshore (SWAN) and DELFT3D-WAVE computer simulation software. Scenarios involving local monsoonal wind forcing and storm conditions were simulated. In addition, as climate change may also result to increased relative sea level, a 0.3 m and 1 m rise in sea level scenarios were also used in the wave model simulations. Results showed that the extensive reef system in the site helped dissipate wave energy that in turn reduced wave run-up on land. A significant reduction in wave energy was observed in both climate change, i.e., stronger wind and higher sea level, and non-climate change scenarios. This present study was conducted in a reef whose coral cover is in excellent condition (i.e., 50 to 80% coral cover). Estimates of coral reef growth are in the same order of magnitude as estimates of relative sea level rise based on tide gauge and satellite altimeter data, thus it is possible that the role of reefs in attenuating wave energy may be maintained if coral reef growth can keep up with the change in sea level. Nonetheless, to maintain reef growth, it is imperative to manage coral reef ecosystems sustainably and to eliminate the stressors that are within human control. Minimizing activities such as illegal and destructive blast and poison fishing methods, pollution and siltation, is crucial to minimize the impacts of high-energy waves that may increase with climate change.  相似文献   
92.
A wind-tunnel experiment was designed and carried out to study the effect of a surface roughness transition on subfilter-scale (SFS) physics in a turbulent boundary layer. Specifically, subfilter-scale stresses are evaluated that require parameterizations and are key to improving the accuracy of large-eddy simulations of the atmospheric boundary layer. The surface transition considered in this study consists of a sharp change from a rough, wire-mesh covered surface to a smooth surface. The resulting magnitude jump in aerodynamic roughnesses, M = ln(z 01/z 02), where z 01 and z 02 are the upwind and downwind aerodynamic surface roughnesses respectively, is similar to that of past experimental studies in the atmospheric boundary layer. The two-dimensional velocity fields used in this study are measured using particle image velocimetry and are acquired at several positions downwind of the roughness transition as well as over a homogeneous smooth surface. Results show that the SFS stress, resolved strain rate and SFS transfer rate of resolved kinetic energy are dependent on the position within the boundary layer relative to the surface roughness transition. A mismatch is found in the downwind trend of the SFS stress and resolved strain rate with distance from the transition. This difference of behaviour may not be captured by some eddy-viscosity type models that parameterize the SFS stress tensor as proportional to the resolved strain rate tensor. These results can be used as a benchmark to test the ability of existing and new SFS models to capture the spatial variability SFS physics associated with surface roughness heterogeneities.  相似文献   
93.
Institutions such as NASA, ESA or JAXA find solutions to distribute data from their missions to the scientific community, and their long term archives. This is a complex problem, as it includes a vast amount of data, several geographically distributed archives, heterogeneous architectures with heterogeneous networks, and users spread around the world. We propose a novel architecture that solves this problem aiming to fulfill the requirements of the final user. Our architecture is a modular system that provides a highly efficient parallel multiprotocol download engine, using a publisher/subscriber policy which helps the final user to obtain data of interest transparently. We have evaluated a first prototype, in collaboration with the ESAC centre in Villafranca del Castillo (Spain) that shows a high scalability and performance, opening a wide spectrum of opportunities.  相似文献   
94.
Mineralogy and Petrology - Potassic-richterite, ideally AKB(NaCa)CMg5TSi8O22W(OH)2, is recognized as a valid member of the amphibole supergroup (IMA-CNMNC 2017–102). Type material is from the...  相似文献   
95.
由戎嘉余主编,金玉玕(已于2006年6月逝世)、沈树忠和詹仁斌任副主编的两卷本《显生宙中国腕足动物属志》已于2017年岁末出版。该志书由24位作者通力协作共同完成,其中有11位来自中国科学院南京地质古生物研究所(NIGPAS),另外13位来自11所海内外高等院校及研究机构。这些作者都有着长期的研究经历以及广博的知识储备,在长达16年严谨繁复的撰写和编改后,最终完成本书。该志书共包含了11个章节以及2目索引,其中索引部分按照字母顺序列出了书中涉及的腕足动物属名以及岩石地层单位。书中引证的参考文献用小号字体列出,总共多达76页。在每个章节之后,这些参考文献条目从3页(“代前言”章节)到14页(“二叠纪腕足动物属级分类”章节)不一而足,并为今后的相关研究提供了翔实准确的资料来源。 该志书包含上下两卷,共1 096页。书籍装帧精美,图文并茂,附有446张高质量插图(其中11张彩色插图)以及125张图版(其中7张配有彩色照片)。图表内容丰富,包括壳体形貌和纹饰的手绘素描、内部构造(如系统切片以及结构复原等),以及时代分布和地理分布等。图版制作考究,并在其对页附有详细的图版说明(包括图片的放大倍数),以方便读者阅读。全书各章节的写作风格与排版格式同条共贯,前后一致。 志书的上下两卷分别配有目录。第一卷开篇是主编戎嘉余院士撰写的15页中文版“代前言”,其后为编辑们(以及乔丽博士和黄冰研究员)共同撰写的38页“序言”。其中“序言”部分介绍了这本著作在编纂过程中所历经的坎坷以及支持作者们最终完成此书的精神源泉。该志书严谨详实地整理并收录了分散在各类期刊、会议摘要、区域化石图册以及公开出版与内部交流的各类专著中有关中国腕足动物属级分类研究的成果,并补充了一些本书作者尚未发表的研究材料。 20世纪70-80年代,中国各地区域古生物图册曾经大量出版,但因为多使用汉语书写,在国际交流时往往会造成一定的不便。经过翻译后,一些新建的属的重要鉴定特征往往表达模糊,而很多报道新材料的文章发表在非古生物学的专业期刊上(如石油勘探或者区域地质等方面的期刊)。这些文献往往由区域性的出版社出版,并且发行量有限,很少被国际上的大型图书馆收藏。这些“稀有出版物”甚至在中国几个较大的科研机构中也往往难得一见。此外,尽管不少区域古生物图册会附有简短的英文摘要,但有可能新属新种的实际情况与他们在书中的简述并不一致。还有一个问题是,当时很多身处基层工作单位的学者在定义新的属种时,没有遵循《国际动物命名法规》(The International Code of Zoological Nomenclature,ICZN,4th Edition)。而这两卷志书的问世,无疑都对这些问题进行了精细的考据和严谨的修订。 在“序言”中,编辑们介绍了中国腕足动物的研究是如何从无到有,又怎样筚路蓝缕、砥砺前行。在中国历史上,腕足动物化石几百年前就作为中药材而被人们所熟知。最早的文献记载可以追溯到公元7世纪,一味被称作“石燕”的药材(“石燕”,性为石而形似燕,多为泥盆纪石燕类腕足动物化石)。但早期的医书并没有对这类生物的起源,以及研磨后产生药效的原因进行讨论。 最早对中国腕足动物进行分类学研究的是比利时古生物学家康宁克(L.G. de KONINCK)。他于1846年描记了腕足动物两个新种Terebratula yunnanensis和Spirifer cheehiel。古生物学家凯瑟(E.KAYSER)最早于1883年依据中国的化石材料建立了腕足动物新属蕉叶贝属(Leptodus),并归至蕉叶贝科(Lyttonidae),同时将李希霍芬贝(L. richthofeni)定义为模式种(KAYSER, 1883)。自此,根据中国的模式标本先后共创建了757个新属,同时随着研究的深入,地层对比精度及腕足动物分类系统日益得到提高与完善。这些研究成果都为该志书的撰写提供了翔实的资料。 费尔南多·阿尔瓦雷斯,约翰·泰兰特/ 地学前缘(Earth Science Frontiers)2019, 26 (3)费尔南多·阿尔瓦雷斯,约翰·泰兰特/ 地学前缘(Earth Science Frontiers)2019, 26 (3) 该志书“序言”部分开篇是腕足动物“研究历史回顾”,将中国腕足动物化石的研究分为以下4个阶段。 第一阶段(1846-1923年)。国外古生物学者如康宁克(LGde KONINCK)、戴维森(DAVIDSON)、凯瑟(KAYSER)、弗伦奇(FRECH)、洛奇(LOCZY)、车尔尼雪夫(TSCHERNYSCHEW)、丁纳尔(DIENER)、华考特(WALCOTT)、韦勒尔(WELLER)、葛梯(GIRTY)、满苏(MANSUY)、矢部长克(YABE)和早板一郎(HAYASAKA)等对中国寒武纪至古近纪的腕足动物进行研究,并发表了相关的研究文章及专著。 第二阶段(1924-1950年)。腕足动物的研究开始吸引中国学者的关注。孙云铸首先报道了山东省寒武系中腕足动物化石,紧随其后的有赵亚曾、朱森、黄汲清、田奇瓗、张鸣韶、尹仲科等老一辈科学家。这一时期在北京大学执教的美籍科学家葛利普教授(A.W. GRABAU,1870-1946)对中国地质学与古生物学的发展做出了卓越贡献,他曾相继发表了数本有关中国腕足类、双壳类和腹足类化石的著作。同一时期还有其他多名国外学者对中国腕足动物的研究做出巨大贡献,如瑞德(COWPER-REED)、德提拉(de TERRA)、哥藤与梅拉尔(GORTANI与MELAR)、小林贞一(KOBAYASHI)、远藤隆次(ENDO)、矢部长克(YABE)、尾崎金右卫门(OZAKI)、湊正雄(MINATO)和早板一郎(HAYASAKA)等。 第三阶段(1950-1991年)。这一时期随着区域地质调查以及地层与古生物研究工作的全面展开,很多新的腕足动物化石群得以发现。在20世纪60年代,两位杰出的中国科学家王钰院士(1907-1984)和杨遵仪院士(1908-2009)做出了卓越的贡献,并培养了一批该领域优秀的国内青年学者。后来他们中的一些人把毕生的精力都投入到了腕足动物研究中。在70年代后期至80年代,全国腕足动物学者已经超过50人。同时这一时期大量的新属新种被创建,并多在23个省及5个自治区的区域古生物图册上发表。该时期标志性的两大事件是1980年在浙江杭州和1985年在云南昆明召开的全国腕足动物会议。在1980年第一届会议上,来自全国各地的腕足动物工作者超过100人,并有两位外籍专家参会。其中一位是对中国腕足动物研究影响深远的美国布科教授(Arthur J.(‘Art’)BOUCOT),另一位是加拿大腕足动物学家、曾任国际沉积学会主席的琼斯教授(Brian JONES)。为了纪念布科教授的贡献,2004年9月30日还在南京地质古生物研究所举办了一次国际学术研讨会(见Palaeoworld,2006年5月第15卷,第2期)。 第四阶段(1991年以来)。这一时期大量的年轻学者涌现,研究重心多集中在传统分类学、地层对比,以及新兴的古生态学和生物古地理学等方面。这一时期全国研究机构、生产单位和高校的科研经费大幅提高,极大地促进了包括腕足动物研究在内的基础科学的研究。在2015年5月,第7届国际腕足动物大会在南京召开,终于实现了几代中国腕足动物学者的夙愿。这次学术盛会共有53个口头报告(其中21个来自中国)、30幅展板报告(其中10幅来自中国),以及来自24个国家195位研究者的108篇会议论文摘要。会议最终取得了圆满的成功。 在“研究历史回顾”后,紧接着介绍了中国古生代和中生代腕足动物属级分类单元的“总体面貌”。该部分内容总结精辟,图文并茂,集中展示了不同省份腕足动物新属的地理分布、每个地质历史时期腕足动物目级和属级分类单元的数量、各目下新属的数量、显生宙各阶中国腕足动物新属的数量,以及建立新属文献的数量统计(自1883至2015年,分别以5年和10年为单位)。这之后是“分类学归纳”,该部分采用国际上通行的腕足动物系统分类体系(Treatise on Invertebrate Paleontology,KAESLER, 1997-2006; SELDEN, 2007),统计出全书共有757个新属或亚属,其中61.6%为有效命名,17.2%为主观同义名(junior subjective synonym),2.6%为可能同义名(possible synonym),1.85%为异物同名(homonym),2.25%为客观同义名(objective synonym),10.6%为疑难名(nomina dubium),3.4%为裸记名(nomina nudum)。另外还有2.4%之前被认为是腕足动物的化石被排除出腕足动物门。此外,“序言”中还包括了腕足动物的时代延限、生物古地理分布(自寒武纪到白垩纪,按年代顺序共分列为9节)、中国腕足动物宏演化、早期类群的多样化、生物大辐射与大灭绝、区域性与全球性生物群(如叶月贝动物群)、生物地理分区的控制因素、重大环境变化与海平面升降、板块构造与地理隔离,以及沉积与环境背景等内容。编辑们在第1卷(39-557页)和第2卷(559-1096页)中,对中国腕足动物的系统古生物学描述做了大量工作,如对新属的命名人、命名地、模式标本及其保存地点等内容的考据。为了避免国外学者受汉语人名翻译的困扰,书中将1950年以前文献中的人名用韦氏音标(WEBSTER spellings)标注,1950年及以后文献中的人名用汉语拼音标注。此外,10篇附录还分别归纳了书中涉及的全部异物同名、同义名、裸记名及18个排除于腕足动物之外的属名,以及标本保存地点及其缩写。 该志书第1卷的其他部分以及整个第2卷,分别按照地质年代顺序(从寒武纪到白垩纪)分章节叙述。每个章节依次有引言、分布范围、地层对比、动物群演替序列、生物古地理以及属级系统古生物等内容。书中的系统古生物学描述部分明晰了各个属的模式种、词源、鉴定特征、讨论、有效性、地层延限和地理分布。 腕足动物门是地质历史上最为复杂、演化多样性最强的六个门之一。该志书通过对中国腕足动物材料的研究和归纳,致力于为该领域的每一位学者、专家和爱好者提供翔实可靠的参考资料。有着近200年研究历史的中国古生代和中生代腕足动物分类学文献浩如烟海。对于本书的作者来说,查阅、整理和归纳这些资料无疑是项浩大的工程。该志书的付梓无疑也是作者、编辑、绘图和出版工作者共同努力的成果。该志书考据细致,资料翔实,是中国古生代和中生代腕足动物属级分类的完整数据库,必然会在未来很长一段时间里成为化石爱好者和古生物学家的案前参考书。书中各分论部分也会在未来有关生物古地理学、生物地层学以及生物演化的研究领域中被广泛引用。而这本著作却鲜有错误出现。 该志书的问世为中国和国外的学者提供了完整的中国腕足动物属级数据库。我们在此真诚地向对腕足动物的系统分类、生物地层和古地理分布等感兴趣的各位专家学者以及爱好者推荐这本巨制。 该志书定价为225美元,尽管并非低价,但它值得每一位腕足动物学者和相关研究单位购买。预算不足的学者也可以建议其所在的研究机构图书馆采购。如果您是一位“中国粉”,即使不从事古生代或中生代的相关研究,也请不要错过这本由科学出版社(北京)出版的装帧精美的鸿篇巨著。 (译者:张雨晨;校阅者:乔丽) (参考文献略)  相似文献   
96.
Bioeroding sponges belong to the most dominant bioeroders, significantly contributing to the erosion of coral reefs. Some species are tolerant or even benefit from environmental conditions such as ocean warming, acidification, and eutrophication. In consequence, increases in sponge bioerosion have been observed on some coral reefs over the last decades. The Abrolhos Bank is the largest coral reef system in the South Atlantic. It has been affected by sedimentation, eutrophication, overfishing, and climate change, mainly affecting coastal reefs, and at lesser intensity outer ones as well. This study aimed to describe spatial and temporal patterns in bioeroding sponge distribution in carbonate substrates in the Abrolhos Bank. Photo‐quadrats were used to compare bioeroding sponge abundance between two shallow reefs: a coastal, Pedra de Leste (PL), and an outer reef, Parcel dos Abrolhos (PAB). Each individual was delimitated over the substrate by determining the sponge surface through a line connecting the outermost papillae. The study was conducted over 6 years in 2008–2009 and 2013–2016. Four species of bioeroding sponges were identified: Cliona carteri Ridley, 1881, C. delitrix Pang, 1973, C. cf. schmidtii Ridley, 1881, and Siphonodictyon coralliphagum Rützler, 1971. The distribution and abundance of species varied between the inner and outer reefs and across the years, and displayed certain selectivity for the calcareous substrates recorded. Crustose coralline algae (CCA) were the main substrate excavated by the most abundant bioeroding species, C. carteri, and represented 70% of the substrate types occupied by this sponge (CCA, coral overgrown by CCA and plain coral). The highest abundance of bioeroding sponges observed in photo‐quadrats was 21.3 individuals/m2 at the outer reefs (PAB) in 2014. The abundances or areal extents of bioeroding sponges were up to 10 times greater on the outer reefs than on the coastal ones, where sedimentation is higher and more strongly influenced by siliciclastic material. Moreover, a higher herbivorous fish biomass has been reported on outer reefs which could also influence the higher abundance of bioeroding sponges in outer reefs. During the study period of 6 years, an increase in bioeroding sponge abundance was observed at the outer reefs (PAB), with the sea surface temperature increase. As CCA have an important role in reefal cementation and carbonate production in the Abrolhos reefs, a bioerosion impact might be expected, in particular, on the outer reefs.  相似文献   
97.
A spatiotemporal calculus for reasoning about land-use trajectories   总被引:1,自引:0,他引:1  
Earth observation images are a powerful source of data about changes in our planet. Given the magnitude of global environmental changes taking place, it is important that Earth Science researchers have access to spatiotemporal reasoning tools. One area of particular interest is land-use change. Using data obtained from images, researchers would like to express abstractions such as ‘land abandonment’, ‘forest regrowth’, and ‘agricultural intensification’. These abstractions are specific types of land-use trajectories, defined as multi-year paths from one land cover into another. Given this need, this paper introduces a spatiotemporal calculus for reasoning about land-use trajectories. Using Allen’s interval logic as a basis, we introduce new predicates that express cases of recurrence, conversion and evolution in land-use change. The proposed predicates are sufficient and necessary to express different kinds of land-use trajectories. Users can build expressions that describe how humans modify Earth’s terrestrial surface. In this way, scientists can better understand the environmental and economic effects of land-use change.  相似文献   
98.
Common basin models assume that the post‐rift tectonic evolution of most basins is usually associated with tectonic quiescence. However, tectonic inversion during the post‐rift phase has been proposed for several sedimentary basins worldwide, but how and why it happens is still a matter of debate, especially in intracontinental settings where the lithosphere is old and thick. Here, we use geological and geophysical data from the Rio do Peixe Basin in NE Brazil to show evidence that intracontinental sedimentary basins can be tectonically inverted by far‐field compressive stresses acting on pre‐existing weakness zones of lithospheric‐scale where stresses can concentrate and inversion can occur. Geomorphological and field data combined with seismic reflection, gravimetric and borehole data show that: (a) inversion occurred along two main Precambrian lithospheric‐scale shear zones, the Patos (E‐W trending) and Portalegre (NE‐SW trending), which had already been reactivated as basin‐bounding faults during the earlier rift stage; (b) post‐rift reactivation affected (mostly) the original master normal faults with the largest rift displacements, and locally produced new reverse faults; (c) during contraction, deformation was partitioned between fault reactivation and buckling of the incompetent sediment pushed against the hard basement; (d) all these signs of inversion have been observed in the field and can be demonstrated on seismic reflection profiles; and (e) combined gravimetric and seismic data show that the main structures of the basin were followed by an inversion. These data are consistent with the operation of WSW‐ENE horizontal maximum compressive stress as a result of combined pushes of the Mid‐Atlantic Ridge (towards the W) and the Andes (towards the E), responsible for the post‐rift oblique inversion of normal faults inherited from the rift phase and formed with vertical maximum compressive stress.  相似文献   
99.
It is well known that individual impairments create disparities in the accessibility of individuals to opportunities, lengthening the distances or time needed to reach them or even completely impeding access. However, the accurate calculation and representation of these disparities remain a major challenge for urban and transportation planners. In this paper, we adopt the concept of accessibility disparity, originally applied to measure place accessibility by different modes of transport, to measure and represent the accessibility of individuals with physical disabilities compared to those without disabilities. We use spatial network analysis to calculate spatial connectivity and the accessibility of Lisbon’s city center, revealing what we define as ‘disability-induced accessibility disparity’. Our results reveal not only the locations responsible for reduced accessibility, i.e., barriers and/or deterrents to movement, but also how much any given disparity reduces the accessibility of an individual, allowing the use of this methodology by planners to identify critical areas and to design inclusive public spaces.  相似文献   
100.
Uncertainty quantification is not often performed in spatial modeling applications, especially when there is a mixture of probabilistic and non‐probabilistic uncertainties. Furthermore, the effect of positional uncertainty is often not assessed, despite its relevance to geographical applications. Although there has been much work in investigating the aforementioned types of uncertainty in isolation, combined approaches have not been much researched. This has resulted in a lack of tools for conducting mixed uncertainty analyses that include positional uncertainty. This research addresses the issue by first presenting a new, flexible, simulation‐oriented conceptualization of positional uncertainty in geographic objects called F‐Objects. F‐Objects accommodates various representations of uncertainty, while remaining conceptually simple. Second, a new Python‐based framework is introduced, termed Wiggly and capable of conducting mixed uncertainty propagation using fuzzy Monte Carlo simulation (FMCS). FMCS combines both traditional Monte Carlo with fuzzy analysis in a so‐called hybrid approach. F‐Objects is implemented within the Wiggly framework, resulting in a tool capable of considering any combination of: (1) probabilistic variables; (2) fuzzy variables; and (3) positional uncertainty of objects (probabilistic/fuzzy). Finally, a realistic GIS‐based groundwater contamination problem demonstrates how F‐Objects and Wiggly can be used to assess the effect of positional uncertainty.  相似文献   
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