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181.
Tarasankar Pal 《Materials and Manufacturing Processes》2006,21(3):315-317
Cetylpyridinium chloride (CPC)-stabilized gold organosol in toluene has been prepared by using a two-phase (water-toluene) extraction of AuCl4- followed by its reduction with sodium borohydride in the presence of the surfactant, CPC. The surfactant-stabilized gold nanoparticles were exploited to examine their optical properties when exposed to various solvent systems by measuring the changes in the localized surface plasmon resonance (LSPR) spectrum. 相似文献
182.
183.
LIXue-mei ZHANGTao 《中国矿业大学学报(英文版)》2005,15(1):72-76
The comprehensive transportation project involves with many different transportation methods, such as railway, highway, waterway, airline, and pipeline, which have their special characteristics. To evaluate the transportation project with different transportation methods under the same system, the integrated evaluation method should be built up on the basis of a common index system. This paper suggests a feasible integrated evaluation method including index system establishing, indices transacting, the index weight distributing, and weighted value integrating. 相似文献
184.
During and after rolling or flattening of metal strips and plates the permissible deviations from flatness are described by the permissible absolute wave height and the flatness index. Both values can be determined on a measuring table while the material is not subjected to global tension. Because this procedure is expensive, time‐consuming and allows measurement only at discrete positions along the strip length, on‐line flatness measuring systems are used which can detect the distribution of longitudinal tensile stresses distributed across the strip width allowing for the calculation of the flatness index. This value does not always agree with the value obtained directly by measuring on the table even when the measurement of the longitudinal tensile stress distribution operates perfectly. It can be shown that the measurement of the tensile stress distribution does not give a direct indication on the wave height in the tension‐free state determined on the measuring table. To explain the relationship between tensile stress distribution in the strip and the flatness measurement on the measuring table, the buckling behavior is analysed both with and without dead load for simple symmetrical residual stress distributions resulting, e.g., from the rolling process. Based on the knowledge of the distribution of the longitudinal residual stresses across the strip width, the flatness index and the wave height can be determined by using a specialized finite element model. If the direct measurement is performed under action of dead load, large differences between the directly and indirectly obtained flatness index are observed. Below a certain limit of the intensity of the residual stress distribution the strips and plates lie flat on the measuring table. Above this limit the strip lying on the table exhibits post‐bucking deformations. In the latter case, the wave height increases with strip thickness and intensity of residual stresses. 相似文献
185.
非化学计量一氧化钛的颜色研究 总被引:1,自引:0,他引:1
在确定非化学计量一氧化钛氧指数范围的基础上,研究了其颜色及其随氧指数的变化规律,并比较了其颜色与现用仿金材料之间的优劣。结果表明,在整个氧指数范围内一氧化钛均呈金黄色;随着氧指数的增大,在可见光作用下,对波长350.550nm范围内的紫、蓝和绿光反射逐渐减弱,对波长650-780nm范围内的红、橙光反射逐渐增强,其颜色从浅金黄色稍带白青色至纯正金黄色,最后至金黄色偏红;氧指数在1.14-1.16范围内其颜色最接近金黄,TiO1.15与24KAu色度差仅为0.0044,较仿金铜、TiN的颜色与24K黄金更为接近。 相似文献
186.
冶金产品在生产过程中,质量指标基本属于单侧控制,在单规过程能力指数计算公式的运用中,由于单控产品质量波动分布有其特殊,其计算公式暴露出了明显的缺陷。确立中心数,探讨计算偏移量的方法,决定偏移程度,弥补过程能力指数计算公式的缺陷,以便使过程能力指数准确地综合反映单控产品质量的状况及过程的质量保证程度。 相似文献
187.
叙述了烧结法氧化铝脱硅工艺的现状,对深度脱硅工艺的技术条件和工艺流程进行了研究。并通过生产实践获得了较好的经济效果。 相似文献
188.
189.
Estimating subpixel surface temperatures and energy fluxes from the vegetation index-radiometric temperature relationship 总被引:5,自引:0,他引:5
William P. Kustas John M. NormanMartha C. Anderson Andrew N. French 《Remote sensing of environment》2003,85(4):429-440
Routine (i.e., daily to weekly) monitoring of surface energy fluxes, particularly evapotranspiration (ET), using satellite observations of radiometric surface temperature has not been feasible at high pixel resolution (i.e., ∼101-102 m) because of the low frequency in satellite coverage over the region of interest (i.e., approximately every 2 weeks). Cloud cover further reduces the number of useable observations of surface conditions resulting in high-resolution satellite imagery of a region typically being available once a month, which is not very useful for routine ET monitoring. Radiometric surface temperature observations at ∼1- to 5-km pixel resolution are available multiple times per day from several weather satellites. However, this spatial resolution is too coarse for estimating ET from individual agricultural fields or for defining variations in ET due to land cover changes. Satellite data in the visible and near-infrared wavelengths, used for computing vegetation indices, are available at resolutions an order of magnitude smaller than in the thermal-infrared, and hence provide higher resolution information on vegetation cover conditions. A number of studies have exploited the relationship between vegetation indices and radiometric surface temperature for estimating model parameters used in computing spatially distributed fluxes and available moisture. In this paper, the vegetation index-radiometric surface temperature relationship is utilized in a disaggregation procedure for estimating subpixel variation in surface temperature with aircraft imagery collected over the US Southern Great Plains. The disaggregated surface temperatures estimated by this procedure are compared to actual observations at this subpixel resolution. In addition, a remote sensing-based energy balance model is used to compare output using actual versus estimated surface temperatures over a range of pixel resolutions. From these comparisons, the utility of the surface temperature disaggregation technique appears to be most useful for estimating subpixel surface temperatures at resolutions corresponding to length scales defining agricultural field boundaries across the landscape. 相似文献
190.
有机醇的结构与色谱保留指数的相关性拓扑指数法研究 总被引:11,自引:6,他引:11
韩海洪 《计算机与应用化学》2003,20(5):687-689
通过计算40种有机醇化合物分子结构的拓扑指数,用多元线性回归将它与气相色谱保留指数进行关联分析,结果获得了良好的相关性,因此,对有机醇各组分在气相色谱上保留指数的理论预测,可作为在色谱分离过程中识别各组分的一种参考方法。 相似文献