Monotonic and nonmonotonic gentzen deduction systems for L3-valued propositional logic

A sequent is a pair (Γ, Δ), which is true under an assignment if either some formula in Γ is false, or some formula in Δ is true. In L₃-valued propositional logic, a multisequent is a triple Δ|Θ|Γ, which is true under an assignment if either some formula in Δ has truth-value t, or some formula in Θ has truth-value m, or some formula in Γ has truth-value f. Correspondingly there is a sound and complete Gentzen deduction system G for multisequents which is monotonic. Dually, a comultisequent is a triple Δ : Θ : Γ, which is valid if there is an assignment v in which each formula in Δ has truth-value≠t, each formula in Θ has truth-value≠m, and each formula in Γ has truth-value≠f. Correspondingly there is a sound and complete Gentzen deduction system G⁻ for co-multisequents which is nonmonotonic.     

析架空输电线路上倍容导线的选择

架空输电线路项目扩容改造,当采用倍容导线时,需在技术和经济上对倍容导线进行比较分析。文章对这种导线的种类、特性情况作了介绍,通过在220kV线路上对倍容导线的选择分析,为同类案例的处理提供了借鉴和参考。     

导磁体在汽车零件感应加热中的应用技术

本文简单介绍了导磁体工作的基本原理，并给出在汽车零件大规模生产中所积累的导磁体应用的一些经验，以阐明如何更有效地使用导磁体。     

铸造铝合金轮毂T6热处理工艺的优化研究

研究了固溶时间、淬火停留时间及涂装烘烤工艺对A356合金铸造轮毂性能的影响规律并优化了T6热处理工艺，将淬火停留时间缩短到2h。研究表明：未涂装时优化工艺使合金抗拉强度达到240MPa，屈服强度达到181MPa。伸长率达到8％；涂装后抗拉强度达到262MPa，屈服强度达到179MPa，伸长率达到9％，接近并达到目前国内T6工艺的强度性能，超过了国内轮毂行业的强度性能标准，具有一定的生产实际意义。     

逆向工程在模具翻新中的应用

利用激光扫描仪及相关CAD三维软件,并用最终产品做辅助,对陈旧的潜水面罩模具进行三维模型的设计,介绍了逆向工程在模具翻新中的应用方法。     

内转子的冷挤压成形工艺及模具设计

介绍了内转子零件的冷挤压成形工艺及其模具设计。     

Preparation and characterization of TiO2 photoelectrode codoped with aluminum and boron and its application in dye-sensitized solar cell

Nanocrystalline titania films codoped with aluminum and boron were prepared by cathodic vacuum arc deposition. In the process, titanium alloy target was used under an O2/Ar atmosphere, and sensitization of films were carried out by natural dye-sensitized complex in anhydrous ethanol. The structure, surface morphology and UV-vis spectra of titania films codoped were measured by X-ray diffraction analysis, scanning electron microscopy and ultraviolet-visible spectrometer. Theas-deposited films are found to be amorphous. The films annealed were examinedto be of anatase structure with orientation along the (101) planes, the averagecrystal size is in the range between 41 and 45 nm. SEM results show that thereare some pores in the codoped titania films, the optical properties of the dye-sensitized films were also measured which reveals that the spectral responses of films shift to the visible region. Under simulated sunlight illumination, the overall energy conversion efficiency of dye-sensitized nanocrystalline solar cell is 0.9%.     

高耐蚀性热镀锌板的钝化处理工艺探讨

介绍了热镀锌板钝化膜的形成机理 ;针对攀钢热镀锌板出现白锈、黑斑等问题 ,分析了钝化液pH值、添加剂及操作条件对钝化膜质量的影响 ,同时提出了改进热镀锌板耐蚀性能的措施     

冷轧工作辊摩擦不稳定分析及其抑制对策

对冷轧机工作辊由于摩擦力引起的垂直、横向振动作了定性分析，指出了它们的危害，提出了预防措施。