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31.
A general flux equation for multicomponent diffusion in oxide melts is presented. An explicit method was developed to calculate the gradients of single-ion activities from those of oxides with the constraints of local equilibrium and electroneutrality. This resolves ambiguity in quantifying the thermochemical driving force for ionic diffusion. A model equation for multicomponent ionic diffusion was derived within the framework of non-equilibrium thermodynamics by de Groot and Mazur. The proposed model takes empirically measurable quantities as input variables, so the diffusion calculations are consistent with thermochemical data, as furnished by the CALPHAD (CALculation of PHAse Diagrams) method, as well as ionic mobility measurements. Although the model is derived for oxides, it can be applied to diffusion in other concentrated liquid electrolytes, such as chloride and fluoride melts. Formulas for multicomponent ionic diffusion in various reference frames are presented with respect to mole fraction.  相似文献   
32.
陆敏  王治乐  高萍萍  王华林 《红外与激光工程》2020,49(4):0426002-0426002-7
为了给海面溢油污染识别检测提供理论基础,根据菲涅尔反射公式的偏振反射系数,结合偏振双向反射率因子和粗糙海面的概率密度分布函数,建立了完善的pBRDF模型,仿真在不同太阳入射角度、不同探测器观测角度以及不同海面风速风向等条件下海水和油膜的偏振反射分布函数。结果表明:海水和油膜太阳天顶角为53°和56°时P偏振反射率分别为1.0×10^-5和2.5×10^-5,S偏振反射率随着太阳天顶角的增加而增加;海面风速越大偏振反射率峰值越小;海面风向只改变pBRDF的空间位置;海水和油膜线偏振度空间分布有明显差异。搭建实验平台相机以40°拍摄时,得出海水和油膜的线偏振度分别在0.2~0.4, 0.5~0.7之间,同时表明利用偏振探测获取目标场景的偏振度和偏振角图可提高图像质量。  相似文献   
33.
The in-situ fabrication of an electron-blocking layer between the Ba-containing anode and the ceria-based electrolyte is an effective approach in suppressing the internal electronic leakage in ceria-based solid oxide fuel cell (SOFC). To improve the thickness of the electron-blocking layer and to research the effect of the layer thickness on the improvement of SOFC, a Ba-containing compound (0.6NiO-0.4BaZr0.1Ce0.7Y0.2O3-δ) modified by Y stabilized zirconia (YSZ) was employed as a composite anode in this research. SEM analyses demonstrated that the thickness of the interlayer can be simply controlled by regulating the proportion of YSZ at anode. The in-situ formed interlayer in the cell with the anode modified by 20?mol% YSZ possesses a thickness of 0.9?µm which is more suitable for the cell achieving an enhanced performance.  相似文献   
34.
魏庆宾 《人民长江》2015,46(10):77-82
大坝运行监测易受自然环境和监测条件影响,存在时间和空间上的变异性,监测数据具有不确定性。以云理论的随机性和不确定性分析方法为基础,并与空间数据辐射思想相结合,建立了云滴概率密度分布估计模型,然后导出云概率密度分布函数,依据样本监测数据推求母体空间数据的分布特征,并设计了基于逆向云算法云变换的计算程序。分析陆浑水库1979~1999年测压管监测数据和位移变形数据的云概率密度分布特征和云数字特征,得出了20 a来大坝的数据分布特征和运行状态。监测数据分析结果表明,云概率密度分布估计不仅能有效合理地分析大坝的运行状态,而且能够依据云数字特征来判断监测状态和监测环境的异常变化。   相似文献   
35.
The time window for effective climate change mitigation is closing. Technological change needs to be accelerated to limit global warming to a manageable level. Path dependence of technological change is one explanation for sluggish diffusion of green technologies. Firms acquire capital that differs by technology type and build up type-specific technological know-how needed to use capital efficiently. Path dependence emerges from cumulative knowledge stocks manifested in the productivity of supplied capital and firms’ capabilities. Increasing returns arise from induced innovation feedbacks and learning by doing. Relatively lower endowments with technological knowledge are a barrier to diffusion for new technologies. This paper shows how the evolution of relative stocks of technological knowledge explains different shapes of diffusion curves. Using an eco-technology extension of the macroeconomic agent-based model Eurace@unibi, it is shown how the effectiveness of different climate policies depends on the type and strength of diffusion barriers. Environmental taxes can outweigh lower productivity and subsidies perform better if lacking capabilities hinder firms to adopt a sufficiently mature technology.  相似文献   
36.
Studies on color preferences are dependent on the topic and the relationships with personal characteristics, particularly personality, but these are seldom studied in one population. Therefore a questionnaire was collected from 1095 Dutch people asking for color preferences about different topics and relating them to personal characteristics. Color preferences regarding different topics show different patterns and significant differences were found between gender, age, education and personality such as being technical, being emotional or being a team player. Also, different colors were mentioned when asked for colors that stimulate to be quiet, energetic, and able to focus or creative. Probably, due to unconsciousness of contexts, many people had no color preference, a result that in the literature seldom is mentioned. Blue was the overall favorite color; however, most males chose for blue (25%) while most females had no color preference (18%). Black was the overall favorite color for clothing, mainly chosen by females (40%), while males primarily chose blue (27%). For building interiors subjects preferred white. For moods, subjects preferred white for being quiet or being able to focus, red for being energetic and had no color preference for being creative. It is concluded that color preferences are dependent upon the topic, and personal characteristics. The findings are important for architects, interior designers, fashion designers and product designers to have a basic idea of preferred colors for different objects by different types of people. © 2013 Wiley Periodicals, Inc. Col Res Appl, 40, 62–71, 2015  相似文献   
37.
The {100} facet of single-crystalline TiO2(B) is an ideal platform for inserting Li ions, but it is hard to be obtained due to its high surface energy. Here, the single-crystalline TiO2(B) nanobelts from H2Ti3O7 with nearly 70% {100} facets exposed are synthesized, which significantly enhances Li-storage capacity. The first-principle calculations demonstrate an ab in-plane 2D diffusion through the exposed {100} facets. As a consequence, the nanobelts can significantly accommodate Li ions in LiTiO2 formula with specific capacity up to 335 mAh g−1, which is in good agreement with the electrochemical characterizations. Coating with conductive and protective poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate), the cut-off discharge voltage is as low as 0.5 V, leading to a capacity of 160.7 mAh g−1 after 1500 cycles with a retention rate of 66% at 1C. This work provides a practical strategy to increase the Li-ion capacity and cycle stability by tailoring the crystal orientation and nanostructures.  相似文献   
38.
Background: Despite increases in ecstasy (MDMA) use in the United States, little is known about characteristics linked with recent-onset ecstasy use, especially psychiatric symptoms and deviant behaviors. Aims: To test whether individuals with high levels of other drug use are more likely to be recent-onset ecstasy users; to test whether psychiatric symptoms in adults are associated with recent-onset ecstasy use; to explore the association between recent-onset ecstasy use and concomitant deviant behaviors in adolescents and adults. Methods: Data from the 2001 National Survey on Drug Use and Health. Findings: Recent-onset ecstasy use was significantly more likely to occur among adolescents and adults (18-34 years old) who engaged in deviant behaviors during the past year as compared with those who did not engage in deviant behaviors during the past year. Higher levels of deviancy indicated a higher likelihood of being a recent-onset ecstasy user, and associations were strongest with nonviolent deviant behaviors such as selling illegal drugs and stealing. Associations between deviant behaviors and recent-onset ecstasy use were similar in strength to associations between deviant behaviors and recent-onset cocaine and marijuana use, respectively. Adults who had past-year psychiatric symptoms (both depressive and panic symptoms) were twice as likely to be recent-onset ecstasy users as compared with those without past-year psychiatric symptoms. Greater levels of drug involvement increased the odds of being a recent-onset ecstasy user. Conclusion: Recent-onset ecstasy use seems to be associated with a range of other behavioral problems and may reflect one aspect of a larger problem behavior syndrome. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
39.
焉耆盆地原油物理化学特征及油源对比研究   总被引:2,自引:2,他引:0       下载免费PDF全文
在焉耆盆地侏罗系三工河组和八道湾组均发现原油,目前关于侏罗系产层原油的油源问题存在不同的认识。对研究区原油的物理、化学性质进行系统的研究,认为侏罗系三工河组和八道湾组原油不仅在物理性质上有一定的差别,而且在地球化学组成及生物标记化合物上也有一定的差异,应具有不同的来源。侏罗系三工河组原油属于典型腐殖型干酪根成因,而侏罗系八道湾组原油除了具有腐殖型干酪根成因的某些特征外,还具有湖相泥岩生烃的特点。通过原油与各类源岩生物标志物进一步对比分析发现,侏罗系三工河组原油与西山窑、三工河组烃源岩及石炭系、三叠系烃源岩地球化学特征均存在明显差异,与侏罗系八道湾组烃源岩对比性较好。侏罗系八道湾组原油与八道湾组、三叠系源岩有一定相似性,因此认为八道湾组源岩为其主要源岩,三叠系源岩也有一定的贡献。目前勘探生产主要以八道湾组烃源岩为目标,下一步应加强对三叠系烃源岩贡献区带的勘探部署。   相似文献   
40.
Experimental study on the effect of strain rate on discontinuous flow and mechanical characteristics of the high-nitrogenous steel Kh23AG19F has been performed. Within the range of strain rates from 4.62 · 10-5 to 1.85 · 10 -4 s-1, discontinuous flow, reflected by serration on the tensile diagram, is chiefly determined by intergranular deformation mechanisms. Under strain rates over 1.85 · 10-2 s-1, combined deformation modes prevail, which cause a change in the character of discontinuous flow and transform a serrated tensile diagram into a wavy graph, with the yield stress of steel increased significantly.  相似文献   
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