安庆皖江发电公司#2炉微油点火技术改造

在石油资源紧张的我国,做为燃油消费大户火力发电厂能否做到点火油耗的降低有着重要的意义。本文基于安徽安庆皖江发电厂#2炉的微油点火改造实际,对微油点火的优点、经济性及存在的问题进行了分析,并总结了经验。     

Effect of mechanical cutting and polishing on the shape memory transformation behavior of NiTi alloy

The results of the studies carried out on the effect of mechanical cutting and polishing on the transformation behavior of Ti-rich NiTi shape memory alloy (SMA) heat-treated at 560 and 660 °C, are presented in this article. Among the samples heat-treated at 560 °C, the sample subjected to mechanical cutting and polishing (HT560MC) shows M → A on reverse phase transformation and A → R → M on forward transformation whereas chemically etched sample (HT560CE) shows the intermediate R-phase both during forward and reverse transformations. Heat treatment at a higher temperature of 660 °C does not facilitate the formation of R-phase in the reverse transformation and helps the formation of R-phase to a very small extent, that too only in HT660MC, during forward transformation due to the reduced dislocation density. Both the heat-treated samples show the effect of mechanical cutting and polishing even at 150th thermal cycling.     

Typechecking top-down XML transformations: Fixed input or output schemas

Typechecking consists of statically verifying whether the output of an XML transformation always conforms to an output type for documents satisfying a given input type. In this general setting, both the input and output schema as well as the transformation are part of the input for the problem. However, scenarios where the input or output schema can be considered to be fixed, are quite common in practice. In the present work, we investigate the computational complexity of the typechecking problem in the latter setting.     

Galois环和剩余类环上逻辑函数的变换

本文利用特征谱对Galois环和剩余类环上逻辑函数变换进行了研究,给出了逻辑函数和变换的逻辑函数密码性质之间的关系,这些密码性质包括平衡性,非线性度,bent函数,完全非线性函数扩散准则。     

Articulating Environmental Grounds

A new generation of thinking is emerging in the manipulation of ground systems that, with the aid of parametrics, is enabling a new level of design precision and ecological calibration. Anne Save de Beaurecueil and Franklin Lee describe how with Diploma Unit 2 at the Architectural Association in London, they are working towards their goal of fusing architecture, landscape and contemporary art through an engagement with articulated ground organisations. Copyright © 2009 John Wiley & Sons, Ltd.     

裂解炉的综合节能措施

介绍了裂解炉通过工艺优化、精心操作来实现经济模式运行;通过加强管理维护、延长设备使用寿命来降低设备更新成本;通过采用新技术、技术改造来回收能量,减少直接能量损失,达到节能降耗、综合节能的目的。     

Martensitic transformation and magnetic properties of aged Ni-Fe-Ga-Ti shape memory alloy

This article reports the effect of ageing on the microstructure, martensitic transformation, magnetic properties, and mechanical properties of Ni51FelsGa27Ti4 shape memory alloy. There are five specimens of this alloy aged at 573 up to 973 K for 3 h per each. This range of ageing temperature greatly affects the microstructure of the alloy. As the ageing temperature increased from 573 up to 973 K, the microstructure of Ni51FelsGa27Ti4 alloy gradually changed from the entirely martensitic matrix at 573 K to the fully austenitic microstructure at 973 K. The volume fraction of precipi- tated Ni3Ti particles increased with the ageing temperature increasing from 573 to 773 K. Further increasing the ageing temperature to 973 K decreased the content of Ni3Ti in the microstructure. The martensitic transformation tempera- ture was decreased steadily by increasing the ageing temperature. The magnetization saturation, remnant magnetization, and coercivity increased with the ageing temperature increasing up to 773 K. A further increase in ageing temperature decreased these raagnetic properties. Moreover, the hardness values were gradually increased at first by increasing the ageing temperature to 773 K, and then dramatically decreased to the lowest value at 973 K.     

点啮合蜗杆传动中的变换矩阵

讨论通过变径蜗杆来实现延伸渐开线圆柱蜗杆的点啮合的方法，给出延伸渐开线点啮合圆柱蜗杆传动中关于蜗杆车削、蜗轮加工及啮合传动时有关的矢量变换乱矩阵和坐标变换矩阵。     

Topotatic-Like Phase Transformation of Amorphous Lead Titanate to Cubic Lead Titanate

The crystallization process of lead titanate (PT) prepared using the polymeric precursor method was investigated using X-ray diffractometry, Raman spectroscopy, electron microscopy, and X-ray absorption spectroscopy techniques. The results showed that amorphous PT was formed by an O–Ti–O structure composed of fivefold and sixfold oxygen-coordinated titanium. The local structure of the amorphous PT phase was similar to that of the cubic PT phase, i.e., similar coordination number and similar bond lengths, leading to a topotactic-like transformation during the phase transformation from amorphous to cubic perovskite PT. Because of the low crystallization temperature, every transformation observed during the crystallization process was associated with a short-range rearrangement process.