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71.
20世纪后半叶是法国大学内部管理结构由雏形到成形的时期。在此过程中形成了一套完整的大学内部管理结构体系,不过,这一结构体系也存在一些问题。作为法国最大的综合性大学,巴黎大学内部管理结构上的问题透视出法国大学内部管理结构中的不足。本论文尝试着以巴黎大学为个案,分析20世纪后半叶法国大学在内部管理结构中的问题,尤其是高校内部两大团体之间的权力消长关系,以期对我国大学内部管理结构建设有所启示。 相似文献
72.
《Electric Power Systems Research》2006,76(6-7):395-403
The problem of grid cost and losses allocation may be divided into independent subproblems: allocation of branch flow and losses to transactions, definition of these transactions and cost allocation to transactions. From this final allocation, the charges to participants in transactions may be made straightforwardly. A differential, slack-invariant method for the allocation of flow and losses to transactions that makes use of the AC load flow equation is presented here. The definition of transactions must be addressed using a non-discriminatory rule in pool systems. There are many possible options for this definition, and the choice made has great influence on the results. Cost allocation, on the other hand, may be made in different ways, as well. The paper presents an allocation process that addresses all these issues. Results for the IEEE-RTS96 test system are obtained and discussed. 相似文献
73.
《Minerals Engineering》2006,19(1):12-18
This paper presents an experimental technique to measure maximum bubble loads, which are then compared with geometrical model estimations. The geometrical models studied assume that a particle monolayer, having a square arrangement, covers the entire bubble surface. Comparison of the experimental and analytical results gave a fairly high statistical correlation (R2 = 0.89), when a shape factor was used for particle volume estimation (λ = 0.32–0.41; [Kelly, E.G., Spottiswood, D.J. Introduction to Mineral Processing, John Wiley & Sons, 1982, p. 491]). This supports the applicability of geometrical models for maximum bubble load estimation. 相似文献
74.
针对连城锰矿4号矿段排土场的特点、影响稳定因素及可能产生的危害,在实践中采取了有效的管理措施,防止了排土场危害的产生,保证了排土场的稳定。 相似文献
75.
本文通过工程实例,说明采用型钢和钢管组合支撑体系,解决高层建筑屋面悬挑曲梁结构的支模难题,保证工程质量和施工安全,并探讨施工中型钢的节点连接做法。 相似文献
76.
本文对非线性锥形梯度折射率透镜进行了分析,根据稳态自聚焦理论以及ABCD定律,导出了高斯光束通过这种透镜光斑尺寸及其位置的公式。讨论了几种特殊的情况,得到了一些重要的结果。 相似文献
77.
78.
Biomimetic synthesis of spherical nano-hydroxyapatite in the presence of polyethylene glycol 总被引:1,自引:0,他引:1
Spherical nano-hydroxyapatite (nano-HA) was synthesized successfully by a biomimetic method using Ca(NO3)2·4H2O and (NH4)3PO4·3H2O as reagents in the presence of polyethylene glycol (PEG). The crystalline phase, microstructure, chemical composition, and morphology of the obtained samples were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM). The results show that spherical nano-HA with diameter of 30–50 nm can be synthesized in the presence of a certain concentration (2–6%) of PEG. The crystallinity of HA powder synthesized in the presence of PEG was higher than that synthesized in the absence of PEG, but the crystallinity of HA reduced with increasing the concentration of PEG. The electrical conductivity (EC) of the solution revealed that PEG reduced the transfer rate of Ca2+ in the process of HA crystallization, indicating the interaction between PEG and HA. The possible mechanism of formation spherical nano-HA was discussed. 相似文献
79.
80.
《Journal of the European Ceramic Society》2006,26(6):967-980
Through a study of Ni–YSZ interfaces it is shown that time-of-flight-secondary ion mass spectrometry (TOF-SIMS) is a powerful and convenient tool for the analysis of ultra thin layers of segregated material at the interfaces and on free surfaces. Two different types of Ni, “pure Ni” (99.995% Ni) and “impure Ni” (99.8% Ni) were investigated. The contact areas on the YSZ and areas outside the contacts were examined with XPS and TOF-SIMS. The impure nickel causes a relatively larger amount of impurities to accumulate at the contact area, e.g. oxides of Mn, Ti, Si and Na. Some impurities migrate to the area outside the contact area. Even though on a larger scale the impurities seem to be homogeneously distributed, detailed analyses in and outside the contact area show the presence of impurity particles, and that the surface species are inhomogeneously distributed amongst the different grains. The extremely low detection limit, the small probe depth, the image capability, and the ease of elemental identification make TOF-SIMS an obvious choice as an analytical tool for studying segregation phenomena at metal–ceramic interfaces such as Ni–YSZ interfaces. XPS, being a quantitative technique, was used as a complementary technique to TOF-SIMS, which is not directly a quantitative technique. 相似文献