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41.
RFID(射频识别)中间件技术是RFID产业化的关键技术,分布式环境下的信息交换是这项技术的主要研究方向之一。随着企业对空间位置信息的关注需求日益增大,空间信息服务也成为RFID中间件中必不可少的组成部分。本文介绍了RFID中间件和空间信息服务的概念,通过一个RFID物流管理系统应用实例研究了空间信息服务在RFID中间件中提供空间信息操作,处理与交换的应用。 相似文献
42.
Leopoldo Franco Jimmy Geeraerts Riccardo Briganti Marc Willems Giorgio Bellotti Julien De Rouck 《Coastal Engineering》2009
The paper presents the comparison between the results of small-scale model tests and prototype measurements of wave overtopping at a rubble-mound breakwater. The specific structure investigated is the west breakwater of the yacht harbour of Rome at Ostia (Italy) and is characterized by a gentle seaward slope (1/4) and by a long, shallow foreshore. The laboratory tests firstly aimed at carefully reproducing two measured storms in which overtopping occurred and was measured. The tests have been carried out in two independent laboratories, in a wave flume and in a wave basin, hence using a two-dimensional (2-D) and a three-dimensional (3-D) setup. In the 2-D laboratory tests no overtopping occurred during the storm reproductions; in the 3-D case discharges five to ten times smaller than those observed in prototype have been measured. This indicates the existence of model and scale effects. These effects have been discussed on the basis of the results of several parametric tests, which have been carried out in both laboratories, in addition to the storm reproductions, varying wave and water level characteristics. Final comparison of all the performed tests with 86 prototype measurements still suggests the existence of scale and model effects that induce strong underestimation of overtopping discharge at small scale. The scale reproduction of wave breaking on the foreshore, together with the 3-D features of the prototype conditions and the absence of wind stress in the laboratory measurements, have been individuated as the main sources of scale and model effects. The paper also provides a comparison between the data and a largely used formula for wave overtopping discharges in the presence of structures similar to the one at hand. The suitable value of a roughness factor that appears in that formula is investigated and good agreement is found with other recent researches on rubble-mound breakwaters. 相似文献
43.
Paola De Rossi Fontanelli Luiz Fernando De Ros Marcus Vinicius Dorneles Remus 《Marine and Petroleum Geology》2009
The provenance of the Maastrichtian deep-water reservoir sandstones from the Jubarte oil field (Campos Basin, eastern Brazil), was studied using an integrated approach that included quantitative petrography, conventional heavy mineral analysis, garnet mineral chemistry and zircon geochronology. The reservoirs are predominantly coarse, poorly-sorted sandstones with feldspathic composition derived from uplifted basement terrains. The fourth- and fifth-order depositional sequences analyzed show no major variations in composition or in provenance through time. However, variations in apatite:tourmaline presents potential to be used as a parameter for sandstone correlation within the field. The composition of heavy minerals indicates derivation from high temperature and low-to-medium pressure aluminous metapelitic rocks, from granites and subordinate mafic rocks, derived from the Cabo Frio Tectonic Domain and the Oriental terrain of Ribeira orogen, characterizing a supply route from SW to NE. The low ZTR index, as well as the absence of low-grade stable heavy minerals and of metasedimentary rock fragments, suggest that by the end of Cretaceous all supracrustal, low-grade terrains had already been totally eroded, and that plutonic, infracrustal rocks were exposed, similarly to the present situation. 相似文献
44.
鲤鱼(Cyprinuscarpio L.)体重和体长QTL的定位 总被引:1,自引:0,他引:1
利用265个AFLP标记、127个微卫星分子标记、37个EST-SSR标记和16个RAPD标记(共445个标记)对大头鲤/荷包红鲤抗寒品系的F2代雌核发育群体44个个体进行基因型检测,构建鲤鱼(CyprinuscarpioL.)遗传连锁图谱;利用软件WinQTLCart2.5采用复合区间作图法对体重和体长两个性状进行了QTL定位分析。结果共检测到与两个与体重性状相关的QTL,分别定位到LG24连锁群(qBWh-24-1)和LG20连锁群(qBWh-20-1)上,可解释的表型变异分别为7.98%和20.05%;检测到两个与体长性状相关的QTL,分别位于LG2连锁群(qFS-2-1)和LG20连锁群(qFS-20-1),可解释的表型变异分别为5.69%和12.69%,4个QTL的加性效应均为负值。 相似文献
45.
CHANG Jing LIU Wanshun HAN Baoqin LIU Bing 《青岛海洋大学学报(英文版)》2008,(4):404-410
Carboxymethyl-chitosan and carboxymethyl-chitin were prepared with the methods developed in our laboratory. The DS (degree of substitution) and DD (degree of deacetylation) of the carboxymethyl-chitosan were 103.14% and 97.18% respectively, while the DS of the carboxymethyl-chitin was 96.37%. Their effects on human fibroblasts, intradermal irritation test, in vitro and vivo degradability, and biocompatibility were evaluated. The results indicate that the polysaccharides at low concentrations can facilitate the growth of human fibroblasts and the carboxymethyl-chitosan at 100 μg mL^-1 is the most effective. The polysaccharides at higher concentrations, however, inhibit the growth of fibroblasts. The PII (Primary Irritation Index) values of CM-chitosan and CM-chitin are both 0.0, which shows that they have no irritation reaction. Both of the polysaccharides show good degradability and biocompatibility. Carboxymethyl-chitin degrades faster in vitro than carboxymethyl-chitosan. The latter, however, has no inflammatory reaction after being implanted in vivo for 7 d and shows better biocompatibility. This study may provide a scientific basis for the use of earboxymethyl-ehitosan and carboxymethyl-chitin as biomaterials. 相似文献
46.
利用1951~2003年HadISST资料集的表层海水温度(SST)资料,讨论了印度洋-西太平洋暖池(IPWP)海域,尤其是印度尼西亚贯穿流(ITF)及其周边海域SST的季节及年际变化的时空特征.研究结果表明,整个研究海域SST的年际变化均与ENSO相关,但印度洋与南海的响应特征与西太平洋的相反且不同步.前者海温变化滞后Nio3指数3~6个月,而热带太平洋西边界和ITF流经海域海温则超前1~3个月.沿ITF及其东印度洋出口,SST的年际变化规律不同于热带印度洋而与太平洋的相似,分析表明其在较大程度上受到ITF海洋桥的影响.在季节尺度上,印度洋和太平洋赤道海域SST的波动规律也有明显不同.以巽他岛弧(苏门答腊、爪哇和小巽他群岛)为界,从赤道西太平洋向西沿ITF流径,太平洋一侧SST的季节变化以0.5a周期的波动占主导,印度洋一侧则以1a周期占主导. 相似文献
47.
48.
无居民海岛开发适宜性评价指标体系的构建和在厦门海域的应用 总被引:2,自引:0,他引:2
无居民海岛开发适宜程度取决于对其生态重要性与开发可行性的综合评价.本研究从表征生态重要性的物种、生境和自然历史文化遗迹,以及反映开发可行性的自然、资源和社会经济条件构建无居民海岛开发适宜性评价指标体系;采用专家咨询法和层次分析法确定指标权重,在评价指标量化与标准化处理的基础上,建立生态重要性-开发可行性互斥矩阵确定无居民海岛的开发适宜程度.对厦门海域的实际应用研究结果表明,其18个无居民海岛的开发适宜性总体偏低,中度适宜开发的海岛共有7个,低适宜开发的海岛有8个,不适宜开发的海岛有3个,评价结果与国家海洋局2011年发布的可供开发利用无居民海岛名录中厦门海域部分基本吻合.作者建议对厦门海域中度适宜开发的无居民海岛可据其资源特征进行适度开发;对低适宜开发的无居民海岛应优先保护海岛生态,维护海岛自然属性;对不适宜开发的无居民海岛应重点加强海岛生态保护,必要时进行生境的重建和修复. 相似文献
49.
地表温度(land surface temperature,LST)是反映生态环境状况的重要指标。西藏作为气候变化的敏感地区,掌握其LST的时空变化有利于深入了解西藏热环境演化过程,为长期监测高原基础生态变化提供帮助。研究基于谷歌地球引擎获取西藏2000—2020年的MODIS LST数据,采用归一化分级方法对LST进行5个等级的划分,利用趋势分析、热力空间分析以及重心迁移等方法分析了研究区近20年来的LST时空演变特征。同时,选取归一化植被指数(normalized difference vegetation index,NDVI)、裸土指数(bare soil index,BI)、垂直不透水面指数(perpendicular impervious surface index,PISI)、湿度(WET)以及高程(digital elevation model,DEM)等5个影响LST的地表参数,结合多尺度地理加权回归,探讨了LST影响因子的作用尺度与作用效力。结果表明:2000—2020年,西藏LST均值由18.72℃上升至20.28℃,年均增长0.09℃,LST呈现微弱上升态势。2... 相似文献
50.