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71.
DI Marlene Haimann ao.Univ.-Prof. i. R. Dr. Otto Moog DI Dr. Ilse Stubauer Priv.-Doz. DI Dr. Michael Tritthart Univ.-Prof. DI Dr. Helmut Habersack 《?sterreichische Wasser- und Abfallwirtschaft》2014,66(9-10):316-326
In the case study “Winterhafen Linz” the effects of dredging/excavating fine sediments previously deposited by flood events and their subsequent dumping into the Danube mainstream were investigated. While this maintenance work was in progress, the temporal and spatial extent of the sediment plume and the changes in bed topography were measured. By employing air-lift samplers and grab samplers in the dredging and dumping areas, the question as to whether, and if so to what extent, the benthic invertebrate community was disturbed by the maintenance work. It could be clearly demonstrated that the sediment dredging severely affected the benthic invertebrates (an 82 % decline in biomass), while the dumping of the material had no effects on the Danube biota. Numerical modeling was used to simulate discharges and dumping locations other than those actually encountered during the monitoring campaign, thus making it possible to extrapolate and draw conclusions beyond the concrete results. These findings in turn provided the basis for recommendations on how to optimize dredging and dumping procedures on the Danube in future. 相似文献
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YAO Yubo JIN Xijun DI Wei GE Huiling MA Chunmei GONG Zhenping 《Canadian Metallurgical Quarterly》2011,18(1)
Nitrogen(N)is considered as an important yield and quality-determining factor in soybean production. The objective of the current experiment was to determine the regularity of N accumulation and its simulation among different varieties, This work was conducted with frame tests (pot without bottom), and three cultivars, HH41, SN14, HN40, and one feed soybean variety MSD was used as materials. The results showed that the regularity of N accumulation in four varieties with the same tendency increased during the whole growth period, wluch was up to the maximum when the plant was harvested. The longer growth period was, the lugher N accumulation of cultivars was, HN40>SN14>HH41, N accumulation of MSD was the lughest because of the property for feed soybean, Regularity of N accumulation in plants could be accurately described by the Logistic equation. During the growth there was a period when N accumulation in the whole plant occurred at an intense rate. The time of onset and its duration varied with different varieties. The maximum daily N accumulation was on seed filling stage, pod bearing stage, seed filling stage and pod bearing stage in HH41, SN14, HN40 and MSD, respectively. 相似文献
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应用复杂网络的理论, 结合统计得到的截止到2014年1月20日的成都市公共交通实际数据, 构建邻接站点式的有向加权复杂网络, 考虑上、下行线路(环线为内、外环)在站点布设和行车方向上的不同对网络拓扑特性的影响, 对成都市公交网络的拓扑特性进行分析。结果表明, 邻接站点式成都公交复杂网络节点平均度为2.52, 节点强度分布不均, 最大值达到45, 平均节点强度为4.75, 网络整体上服从幂律分布, 具有较为明显的小世界特性。随着网络规模由成都市区向郊区扩张, 网络平均最短路径长度由16.90增至34.19, 增长明显。网络聚集系数0.14, 体现出相对较高的公交路网发展水平。
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为研究回火温度对F/B结构钢力学性能的影响,利用力学性能测试、光学显微镜、透射电镜等方法,研究了回火温度对控轧+弛豫+控冷工艺生产的420 MPa级结构钢组织及力学性能的影响。研究结果表明,回火过程中F/B钢两相比例未发生变化,随着回火温度的升高,M-A岛发生了分解且F晶粒长大;同时,钢板的屈服强度上升明显,但抗拉强度变化较小,由此带来屈强比由0.80升至0.88,为回火过程中组织的回复、F晶粒长大、析出以及位错的相互作用综合影响的结果。结合去应力目的及满足屈强比技术条件的要求,推荐的回火工艺为:(400±10) ℃, (2×厚度)min。 相似文献
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Research on novel cast and wrought superalloy FGH4096 for aircraft turbine disk applications 总被引:1,自引:0,他引:1
The ingot metallurgy of electro- slag remelting continuous directional solidification(ESR- CDS) followed by multiple forging and isothermal forging, a novel cast and wrought(C&W) routes for preparation of FGH4096 turbine disk, was developed to solve the difficulties of microstructure controlling, the macro- segregation, poor processing of ingot with high alloying element used for the turbine disk of advanced aircraft engine. From aspects of ingot microstructure characteristics, hot working plasticity, microstructure controlling, mechanical properties and strengthening mechanisms, the preparing processes of C & W superalloy FGH96 turbine disk were studied. The formation of bulk ?? phase, borides phase and carbonitride strips can be avoided by the directionally solidified ingot, which resulted in excellent hot working plasticity. Multiple forging was applied to achieve the homogeneity of microstructure. The grains are fine in different parts of the billet, and the deformation dead zone can be eliminated. The mean grain size for alloy billet is close to ASTM 9-10. Because of the fine grains and the homogeneity of microstructure, the ultra- inspection capability for disk forging can be significantly improved. With the increase of solution temperature, the yield strength decreases. Under sub- solvus temperatures, the creep resistance decreases with the increase of solution cooling rate. The micro- twining shearing is the main creep deformation mechanism for the samples from disk rim. 相似文献
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在单因素试验的基础上,采用响应面分析法对灵芝液体发酵菌丝体中合成Agaricoglyceride A的前体物质(二氯茴香酸、甲醇、甘油)加入量进行优化,筛选提高Agaricoglyceride A含量的前体物质的最适添加量。并采用高效液相色谱-蒸发光散射检测器(HPLC-ELSD)法对Agaricoglyceride A含量进行检测。结果表明,同时加入二氯茴香酸75 mg/L,甲醇1.5 mL/L,甘油1.5 mL/L对灵芝进行发酵培养,测定得到Agaricoglyceride A的实际含量为21.09 mg/L,与不添加任何前体物质相比,Agaricoglyceride A的含量提高了25.31%。 相似文献
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