UV胶油墨的制备及其触变性的研究

制备了UV胶印油墨样品,探讨了油墨样品的触变性.实验结果表明:UV胶印油墨具有触变性,油墨触变性的评价结果与测试模式有关.相同最大切变速率下,切变速率变化时间长触变环面积小;相同切变速率变化时间下,最大切变速率越小触变环面积越大.     

Remote sensing of wetlands in South America: status and challenges

South America has a large proportion of wetlands compared with other continents. While most of these wetlands were conserved in a relatively good condition until a few decades ago, pressures brought about by land use and climate change have threaten their integrity in recent years. The aim of this article is to provide a bibliometric analysis of the available scientific literature relating to the remote sensing of wetlands in South America. From 1960 to 2015, 153 articles were published in 63 different journals, with the number of articles published per year increasing progressively since 1990. This rise is also paralleled by an increase in the contribution of local authors. The most intensively studied regions are the wetland macrosystems of South American mega-rivers: the Amazon and Paraná Rivers, along with the Pantanal at the headwaters of Paraguay River. Few studies spanned more than two countries. The most frequent objectives were mapping, covering all types of wetlands with optical data, and hydrology, focusing on floodplain wetlands with microwave data as the preferred data source. The last decade substantial growth reflects an increase in technological and scientific capacities. Nevertheless, the state of the art regarding the remote sensing of wetlands in South America remains enigmatic. Fundamental questions and guidelines which may contribute to the understanding of the functioning of these ecosystems are yet to be fully defined and there is considerable dispersion in the use of data and remote-sensing approaches.     

On the formal semantics of IF-like logics

In classical logics, the meaning of a formula is invariant with respect to the renaming of bound variables. This property, normally taken for granted, has been shown not to hold in the case of Independence Friendly (IF) logics. In this paper we argue that this is not an inherent characteristic of these logics but a defect in the way in which the compositional semantics given by Hodges for the regular fragment was generalized to arbitrary formulas. We fix this by proposing an alternative formalization, based on a variation of the classical notion of valuation. Basic metatheoretical results are proven. We present these results for Hodges' slash logic (from which these can be easily transferred to other IF-like logics) and we also consider the flattening operator, for which we give novel game-theoretical semantics.     

ZnO-Al_2O_3-B_2O_3-SiO_2系微晶玻璃与可伐合金的润湿性能

研制了一种新型的与可伐熔封的ZnO-Al_2O_3-B_2O_3-SiO_2系微晶玻璃,研究了不同工艺条件下微晶玻璃与可伐合金间的润湿角大小,结果表明,熔封气氛和熔封温度对润湿性能影响很大,熔封时间影响最小.采用最佳的工艺条件,其润湿性能与现有的其它玻璃润湿性能相似.同时发现玻璃与可伐合金间的润湿角保持在10°～30°之间能得到质量良好的熔封产品.在基本不改变传统工艺制度的条件下,可完成锌铝硼硅系微晶玻璃与可伐合金的熔封,即利用排蜡过程同时完成微晶玻璃的形核,熔封后在稍低温度保温或减慢冷却速度可以完成微晶玻璃的结晶过程.锌铝硼硅系微晶玻璃与预氧化可伐合金的封接依靠玻璃中的SiO_2与FeO或Fe_3O4发生界面反应形成牢固的结合.     

Superload Evaluation of the Bonnet Carré Spillway Bridge

The passage of overloads that require special permitting is a common occurrence. Prior to the passage of such an overload, a simplified computer analysis is generally conducted to predict the expected behavior of the bridge. This paper addresses the field evaluation of three superloads that crossed the Bonnet Carré Spillway Bridge in Louisiana. Emphasis is placed on comparisons between the expected and actual behavior due to rotational restraint, live load distribution, the stiffening effect of bridge rails, and other factors. Finite-element modeling was conducted and the approach taken along with the results obtained are described. One important conclusion was that the longitudinal configuration of the axle loads supplied by the hauler was configured differently than indicated on the permit. While the gross load was accurate, the distribution between sets of axles varied considerably from those assumed in the permitting process. To minimize the potential for damage to bridges it is therefore recommended that axle loads be weighed prior to the passage of such overloads.