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排序方式: 共有71条查询结果,搜索用时 15 毫秒
61.
文章综述了汽车用金属材料化学成分的各种分析方法,包括火花源放电原子发射光谱、波长色散X射线荧光光谱、原子吸收光谱、电感耦合等离子体发射光谱、电感耦合等离子体发射质谱、红外吸收法和热导检测仪等的研究进展,探讨了各类方法的优缺点。  相似文献   
62.
上海地铁车辆车轮的开发   总被引:1,自引:1,他引:0  
从设计标准及基本要求方面介绍上海地铁车辆用车轮的技术特点;用有限元方法进行车轮强度和制动热力学计算,给出其强度和疲劳评估;讨论车轮疲劳试验方法,并给出了试验结果。  相似文献   
63.
对废旧沥青混合料中回收沥青的化学结构、流变性能和废旧沥青混合料中沥青变异性、级配变异性进行试验分析,综合评价了废旧沥青混合料的性能。  相似文献   
64.
This study aims at quantifying the distribution of REEs associated with chemical weathering processes, as well as investigating weathering mechanisms and source regions of the Gaoping (formerly spelled Kaoping) River (KPR) catchment basin located at southwestern Taiwan. Spatial distributions of dissolved rare earth elements, as well as major ions, trace elements and Sr isotopes in river waters were analyzed using SF-ICPMS and TIMS. Our results indicate that REE concentrations and patterns predominantly reflect sources and intensity of chemical weathering along the river's catchment. Most specimens have high Na/Cl (4.2–30.1 mol/mol) ratios due to strong weathering intensity in the upper stream. The Na/Ca and Mg/Ca ratios suggest the main contribution is from weathering of silicates and carbonates. Total concentrations of REEs are rather low in the Gaoping (Kaoping) River (6.7–15.4 ng/L), possibly influenced by adsorption onto suspended particles. The REE patterns also reflect source heterogeneity in weathering minerals with large LREE depletion and MREE enrichment. Europium is strongly enriched in the Gaoping (Kaoping) River water, as a result of its preferential dissolution from suspended particles. Unique Gadolinium anomaly is present in all specimens, likely related to contamination due to clinic waste disposal. Small fractionations of LREE/HREE have occurred along the KPR and can be used as a distinct signature for source identification. The main stream samples exhibit a relatively wide range of 87Sr/86Sr, 0.71265–0.71360, with a systematical increase downstream due to source mixing of dissolved basalt (less radiogenic) and sedimentary rocks. Each tributary shows distinct Sr isotope signatures due to different rock types and ages. These isotopic and elemental compositions provide important information on weathering source and erosion budget.  相似文献   
65.
针对汽车主机厂涂装车间产生的磷化废水,采用化学沉降法去除废水中的镍离子。分别进行了pH值、凝聚剂、絮凝剂投加量以及沉降时间(系统停留时间)对镍离子去除效果影响的试验。结果表明,最佳工艺条件为pH>10.5,沉降时间>4 min,在足够的凝聚剂和适宜的絮凝剂投加量的条件下,废水中镍离子去除率在99.0%以上。将最佳工艺条件应用于工程实际中,废水处理后,出水的镍离子浓度可控制在0.05 mg/L以下,远低于1 mg/L,满足了GB 8978—1996《污水综合排放标准》中镍的排放标准。  相似文献   
66.
The dense overflow across the Denmark Strait is investigated with hydrographic and hydro-chemical data and the water mass composition of the Denmark Strait Overflow Water (DSOW) is determined by multivariate analysis. Hydrographical properties, the transient tracers CFC-11 and CFC-12, oxygen and nutrients are utilized for the water mass definitions. Distribution and characteristics of water masses north of Denmark Strait are described, the important water masses at the sill and the variability on weekly time-scales are discussed, and the entrainment and mixing of water into the overflow plume in the northern Irminger Basin is calculated. The analysis indicates that water masses both from the Nordic Seas and the Arctic Ocean are important for the formation of DSOW. It is found that water masses transported with the East Greenland Current make up about 75% of the overflow at the sill. The overflow at, and shortly south of, the sill is inhomogeneous with a low-salinity component dominated by Polar Intermediate Water. The high-salinity component of the overflow is mainly of Arctic origin. The water mass composition, and the short-term variability for 7 repeats of sections close to the sill are described, and these illustrate that the overflow is in fact a composite of a number of water masses with different formation and transport histories. This indicate that the overflow is a robust feature, but that it responds to variations in the circulation or atmospheric forcing that influences the formation of intermediate and deep water masses within the Arctic Mediterranean and the North Atlantic. At a section about 400 km south of the sill the overflow is well mixed and modified by entrainment of, mainly, Iceland–Scotland Overflow Water and Labrador Sea Water, together constituting 30% of the overflow plume. The entrainment of Middle Irminger Water dominates shortly downstream of the sill, before the overflow plume reaches too deep but the entrainment seems to be intermittent in time.  相似文献   
67.
淮安盐化工新区专用线接轨于既有新长线袁北站,其后方通路的选择对项目的最小曲线半径、牵引质量、到发线有效长度、闭塞类型等主要技术标准的选取产生影响,从而论证专用线项目后方通路的选择需综合考虑多方面因素来确定。  相似文献   
68.
分析了温拌沥青混合料在国内外发展应用状况,按照工作机理,将各种温拌沥青混合料分为三类,详细介绍了各类温拌沥青混合料制备方法与流程,归纳总结各类温拌沥青混合料应用概况。  相似文献   
69.
当代化学品船发展综述   总被引:2,自引:0,他引:2  
对当代化学品和化学品船进行了分类,介绍了化学品船的发展历史,分析了化学品船和化学品船船队发展现状,对化学品船市场及其发展趋势作了展望。  相似文献   
70.
利用美国Lawrence L ivermore国家实验室公布的乙醇燃烧的复杂化学动力学机理和热力学数据,建立了乙醇HCC I燃烧模型。对模型中复杂化学反应动力学刚性问题采用了能够自动调节步长的Gear向后差分法。分析了进气温度、进气压力、压缩比、当量比等因素对燃烧特性的影响。计算结果对燃用乙醇的HCC I燃烧过程的模拟和分析提供了依据。  相似文献   
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