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为满足海洋环境下高性能混凝土的施工要求,开展了复掺粉煤灰与石灰石粉海工自密实高性能混凝土的试验研究。试验结果表明,在复掺粉煤灰和石灰石粉掺量为40%的条件下,掺入10%~30%粉煤灰自密实混凝土具有较高的流动性、填充性、间隙通过性和抗离析性等工作性,满足自密实混凝土的施工要求;28 d抗压强度大于50 MPa,56 d的电通量小于1 000 C,90 d扩散系数小于1.5×10-12 m2/s,具有较高的抗压强度和抗氯盐侵蚀性能,满足海洋环境下抗氯盐侵蚀的耐久性要求。 相似文献
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为满足海洋环境下高性能混凝土的施工要求,开展了复掺粉煤灰与矿渣粉海工自密实高性能混凝土的试验研究。试验结果表明,在复掺粉煤灰和矿渣粉掺量为60%~70%的条件下,掺入20%~30%粉煤灰自密实混凝土具有较高的流动性、填充性、间隙通过性和抗离析性等工作性,满足自密实混凝土的施工要求;28 d抗压强度大于50 MPa,56 d的电通量小于1 000 C,90 d扩散系数小于1.5×10-12 m2/s,具有较高的抗压强度和抗氯盐侵蚀性能,满足海洋环境下抗氯盐侵蚀的耐久性要求。 相似文献
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沙特红海10、11、12号酒店栈桥和浮码头项目U型梁预制厂处于高温干热环境,U型梁预制需要满足早强和抗裂的要求。基于当地的材料特点和环境条件,根据自密实混凝土的配合比设计原则和流程提出干热环境下的试验室配合比,通过试验验证了自密实混凝土的工作性能和强度,确定了混凝土生产时的加冰量范围。现场布设测温监控混凝土内外温差,满足规范规定温控设计要求及当地施工要求。经裂缝探伤检测,混凝土U型梁的完整性满足要求,对后续同类工程具有一定的借鉴意义。 相似文献
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采用粉煤灰、矿渣粉、石灰石粉、硅灰等矿物掺合料,配制海工自密实高性能混凝土,对其收缩性能进行了研究。结果表明,掺入粉煤灰和石灰石粉可降低海工自密实高性能混凝土自收缩和干燥收缩,可配制出收缩较低的海工自密实高性能混凝土,提高其抗裂性。 相似文献
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本文依据优选原材料及外加剂匹配试验,设计9种配合比,在配合比满足强度考核要求前提下,分析掺合料对混凝土强度的影响。并进一步开展不同介质水中水下自密实混凝土冻融试验,分析不同掺合料配比条件下,混凝土质量损失率、相对动弹性模量随冻融循环次数的变化规律。研究表明,本文采用的配合比不仅满足水下自密实混凝土的力学性能要求,还具有良好的抗冻融性能。 相似文献
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FOB、CIF、CFR与FCA、CIP、CPT价格术语应用与案例分析 总被引:1,自引:0,他引:1
FOB、CIF、CFR与FCA、CIP、CPT价格术语在运输方式、风险转移点、提单签发人、时间、地点、性质及运费计收、保险区段、运输合同订立等方面存在差异,国际商会自上世纪20年代起即不断对有关价格术语进行研究和解释.但由于国际贸易、运输的发展,人们对新、老价格术语中买卖双方的风险转移、责任、费用的划分时常难以理解.本文中作者试通过案例分析说明之. 相似文献
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C. Pohl P.L. Croot U. Hennings T. Daberkow G. Budeus M. Rutgers v.d. Loeff 《Journal of Marine Systems》2011,84(1-2):28-41
Surface seawater samples were taken in the framework of the GEOTRACES program on “POLARSTERN” expedition ANT XXIII/1 in the Eastern Atlantic in 2005 to study the distribution of the trace elements Hg (mercury), Pb (lead), Cd (cadmium), Cu (copper), Ni (nickel), Zn (zinc), Co (cobalt), Mn (manganese), Fe (iron), and Al (aluminium). With the exception of Hg, results were compared to earlier datasets from 1989 to 1990. The particulate fraction averaged over the transect was calculated to be 49% for Cd, 23% for Mn and 50% for Fe indicating a release of these TEI's (trace elements and their isotopes) from a leachable SPM fraction in the stored and acidified samples.Total Pb concentrations ranged between 5 and 20 pmol kg? 1 in 2005 with highest values in the ITCZ (intertropical convergence zone). In 1989 Pb concentrations were twice as high in the region of the ITCZ, while by a factor of 10–15 higher values were obtained in the North Atlantic.Total Cd and Co are dominated, by different seasonal upwelling regimes (Equatorial upwelling, Guinea Dome, Angola Dome).Total Cu, Ni, Fe, Mn and Al show nearly identical concentrations in 1990 and 2005. For total manganese and aluminium strong maxima (3–4 nmol kg? 1 and 55 nmol kg? 1 respectively) are observed between 23°N and 0°, while the Fe maximum (6–9 nmol kg? 1) is located at 7°N. Total Hg concentrations ranged between 0.5 and 4.5 pmol kg? 1. 相似文献
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海天 《舰载武器(含VCD光盘)》2008,(1):46-49
CVN-77“乔治·布什”号航空母舰是美国海军“尼米兹”级超级航母的第十艘,也是该纫的最后一艘,是美国海军第十一艘核动力航空母舰,也是美国海军中第一艘以“布什”(美国第41任总统,现任总统小布什之父)命名的战舰。据称,CVN-77之所以以老布什的名字命名,不仅是因为他曾任美国总统,曾领导美国打赢了1991年的海湾战争,而且缘于他与美国海军及航母有很深的渊源:早在1942年,18岁的布什就参加了美国海军并于次年成为一名舰载机飞行员, 相似文献
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Marc L. Miller 《Coastal management》2013,41(4):301-311
Abstract Marine and coastal zone policy represents a collaboration of people managing and people managed. This paper takes a holistic stance in suggesting that marine communities are viewed properly as networks of focused interest groups, policymakers, professionals, and publics. The interplay between culture and marine and coastal policy is appropriately one topic of applied social research. Seven ethnographic studies in this domain are introduced in this theme issue and help us to understand sociocultural processes and institutions bearing on marine affairs. 相似文献
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Joan M. Bondareff 《Coastal management》2013,41(2):147-161
Congress has not been able to pass comprehensive oceans policy legislation in recent years. Nonetheless, significant individual oceans policy measures have been enacted. These are reviewed in the article. A Joint Committee on the Organization of Congress has been established to recommend reforms in how Congress conducts its business, including proposals for committee restructuring. These proposals could affect how Congress examines oceans policy issues, but it is unlikely that these reforms will make it easier to pass comprehensive oceans policy legislation. For this to happen, well‐organized constituencies have to demonstrate support for this legislation, which has not happened to date. 相似文献
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工业界的压力主要来自政治记者:当今,政府对环境保护的要求越来越高,有所谓“零容忍度”的环境要求之说。在此情形之下,油轮承受的压力最大。ICS一项重要的工作是制订综合性的政策。在政策制订方面,ICS将作何考虑?Horrocks:我们面临的挑战是“灾难”。1978年的英国溢油事件,199 相似文献
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在世界经济加速全球化的背景下,港口如何应对船舶日益大型化发展态势?吞吐量日益攀升,如何保持港区道路畅通有序?面对恐怖主义威胁,作为物流前沿阵地的港口在保安问题上有何良策?在环保日益受到重视的今天,港口又将担当何种角色?2006年10月25日,一年一度的“大厦组织”会议开幕。来自美国长滩港、纽约/新泽西港、荷兰鹿特丹港、新加坡港以及中国上海港等世界五大港的港务局局长、总裁或首席执行官齐聚上海,就当今世界港口发展最前沿的问题展开对话。 相似文献
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