Isolated ovarian polyarteritis nodosa

Polyarteritis nodosa is a rare disorder and a form of systemic vasculitis. A 48 year-old female was admitted to the hospital because menorrhagia and pelvic pain in February 1993. The patient underwent exploratory laparotomy resulting in a total hysterectomy and bilateral salpingo-oophorectomy for myoma of uterus and a right adnexal cystic mass. Histopathologic examination revealed left ovarian periarteritis nodosa. Further investigation and 9 months follow-up failed to show any systemic involvement. To our knowledge the isolated ovarian polyarteritis nodosa is the first case in the literature.     

A new method for power generation planning and problems of uncertainty

This paper presents a new method for power system planning which considers uncertainties of various system parameters as a part of the criterion function. The criterion function involves both the expected values of total system costs and the cost variances of different power plants. Previously, the authors proposed that these cost variances be evaluated from the existing power system plans in the form of the solutions to the inverse optimization problem, and then applied this procedure to the planning of power systems in Japan. However, because of the correlation between fuel and facility costs, the cost variances could not be determined as specific values. Here, to overcome this difficulty, the authors now introduce hydropower plants into the model as the so-called nonrisky elements and focus on the expenditure shares rather than the plant capacity shares. As a result, more reasonable results are obtained. This improved methodology is applied and the derived cost variances are shown. Further, using the resultant cost variances, the authors make Pareto-optimal power generation plans and demonstrate also the robustness of the method to price fluctuations.     

Selectivity in Methanol Oxidation as Studied on Model Systems Involving Vanadium Oxides

Oxidation catalysts are modeled by oxide single crystals, thin oxide films, as well as supported oxide nanoparticles. We characterize the surface of those materials using a variety of surface sensitive techniques including scanning tunneling microscopy and spectroscopy, photoelectron spectroscopy, infrared spectroscopy, and thermal desorption spectroscopy. We find temperature dependent structural transformations from V₂O₅(001) to V₂O₃(0001) via V₆O₁₃(001). V₂O₃(0001) is found to be vanadyl terminated in an oxygen ambient and it loses the vanadyl termination after electron bombardment. It is shown that the concentration of vanadyl groups controls the selectivity of the methanol oxy-dehydrogenation towards formaldehyde. A proposal for the mechanism is made. The results on single crystalline thin films are compared with similar measurements on deposited vanadia nanoparticles. The experimental results are correlated with theoretical calculations and models.     

Transmission electron microscope study of a directionally solidified Cu-MgCu2 eutectic

The crystallography and the interface structure of a unidirectionally solidified Cu-MgCu₂ eutectic alloy have been examined by transmission electron microscopy. The microstructure of the eutectic was found to be lamellar and regularly interrupted by faults. The preference of the particular orientation relationship could not be explained by relative atomic densities of the planes comprising the interface. Based on the defect contrast observed and extinction distance calculations, it is suggested that the fine array of defects observed at the interface may be characterized as steps with step vectors parallel to or Dislocations were also observed at the interface but they were rarely regular.     

Effect of aging temperature and of retrogression treatment time on the microstructure and mechanical properties of alloy AA 7075

Alloy AA 7075-T6 is studied after retrogression and re-aging. The retrogression heat treatment is performed at various temperatures and hold times, and subsequent aging is performed at 130°C for 12 h. The microstructure and mechanical properties of the alloy are studied depending on the temperature and the hold time of the retrogression heat treatment. Electron microscopic studies are preformed and mechanical characteristics are determined in tensile and impact tests. The HRB microhardness is measured.     

Modification of γ-(Fe,Cr)3C pseudo-binary eutectic

The -(Fe, Cr)₃C pseudo-binary eutectic alloy with K, Ce, Sb additives was unidirectionally solidified in a Brigdman-type unit. The quasi-regular, lamellar eutectic carbide was changed into rods and bent blades by the modifiers under well-controlled conditions. At very slow growth, partial modification was common. At growth rates corresponding to a slightly cellular interface, a fully modified structure could be obtained. The modification behaviour as a function of the modifying element, its concentration and the growth rate is described and discussed.     

以第一性原理研究立方相CeO2的弹性、电子结构和光学性质

运用基于密度泛函理论(DFT)框架下的超软赝势平面波(USPP)方法,计算了立方相CeO2的几何结构、弹性性质、电子结构和光学性质,并采用HSE06杂化泛函矫正了带隙.所得晶格参数及体模量与先前文献报道数据基本吻合.计算出了二阶弹性常数及德拜温度值,并给出了能带结构、态密度、差分电荷密度的分布情况.最后,为了阐明CeO2的光学跃迁机制,计算并分析了其复介电常数、折射率、吸附光谱、反射光谱等光学性质.