北京房山侵入岩体主要由石英二长闪长岩单元和三种不同结构的花岗闪长岩单元组成,岩体中广泛分布的镁铁质微粒包体、富集暗色矿物的线状条带以及各岩相单元的非渐变接触关系等宏观特征,指示岩体的形成与岩浆混合作用有密切联系。122个...北京房山侵入岩体主要由石英二长闪长岩单元和三种不同结构的花岗闪长岩单元组成,岩体中广泛分布的镁铁质微粒包体、富集暗色矿物的线状条带以及各岩相单元的非渐变接触关系等宏观特征,指示岩体的形成与岩浆混合作用有密切联系。122个斜长石成分剖面电子探针分析表明,它们众数成分为 An=29的更长石。但是,其成分变化范围极宽(An=14~56),晶体内不同部位的成分有很大差别,出现正常环带的 An 值较低(14~42),内环带的 An 值较高(24~56)的特殊情况,指示斜长石结晶环境的改变,暗示具有富钙基性岩浆的加入。从岩体边部到中心,斜长石 An 牌号逐渐降低,但相邻岩相单元之间有较大的重叠,表明不同岩石单元中的斜长石成分主要受控于岩浆成分的变化,与分离结晶作用无关。斜长石的韵律性环带、特别是内环带的发育则是岩浆混合作用机制的有力证据。基性岩浆的反复注入不仅改变寄主岩浆的成分,而且也控制了它的温度、定位机制和岩石的结构特征。因此,房山岩体的形成过程还包含了镁铁质岩浆多次注入的历史,并且从外到里基性岩浆的作用逐渐减弱。展开更多
The environmental potential of perforated surfaces in the tropics is noticeable. They allow obtaining higher attenuation and spatial dispersion of both direct and diffuse lighting in indoor spaces, whereas in outdoor ...The environmental potential of perforated surfaces in the tropics is noticeable. They allow obtaining higher attenuation and spatial dispersion of both direct and diffuse lighting in indoor spaces, whereas in outdoor areas, the openwork elements reduce surfaces temperature and mitigate the characteristic glare of smooth surfaces when exposed to sunlight. Openwork walls have an immense sustainability potential in modern tropical buildings: they limit the solar rays' admission, as well as provide an advantageous use of natural light and cross ventilation, but the research on their solar behavior is scarce. In order to obtain suitable levels of solar gain, relationships among shape, proportion, thickness and partitions composing openwork elements must be studied. This research evaluates solar gain in perforated surfaces by defining the "solar applicability range", a property useful to identify intervals of guidance where a perforated pattern shape will present a definite solar gain, giving valuable input in the geometric design of openwork elements and introducing shade performance in the design of openwork walls. Results give geometric guidelines that allow to widen the solar applicability range of a perforation pattern and to define two perforation features that have impact on the solar performance of perforated surfaces: focalization and solar performance shift.展开更多
文摘北京房山侵入岩体主要由石英二长闪长岩单元和三种不同结构的花岗闪长岩单元组成,岩体中广泛分布的镁铁质微粒包体、富集暗色矿物的线状条带以及各岩相单元的非渐变接触关系等宏观特征,指示岩体的形成与岩浆混合作用有密切联系。122个斜长石成分剖面电子探针分析表明,它们众数成分为 An=29的更长石。但是,其成分变化范围极宽(An=14~56),晶体内不同部位的成分有很大差别,出现正常环带的 An 值较低(14~42),内环带的 An 值较高(24~56)的特殊情况,指示斜长石结晶环境的改变,暗示具有富钙基性岩浆的加入。从岩体边部到中心,斜长石 An 牌号逐渐降低,但相邻岩相单元之间有较大的重叠,表明不同岩石单元中的斜长石成分主要受控于岩浆成分的变化,与分离结晶作用无关。斜长石的韵律性环带、特别是内环带的发育则是岩浆混合作用机制的有力证据。基性岩浆的反复注入不仅改变寄主岩浆的成分,而且也控制了它的温度、定位机制和岩石的结构特征。因此,房山岩体的形成过程还包含了镁铁质岩浆多次注入的历史,并且从外到里基性岩浆的作用逐渐减弱。
文摘The environmental potential of perforated surfaces in the tropics is noticeable. They allow obtaining higher attenuation and spatial dispersion of both direct and diffuse lighting in indoor spaces, whereas in outdoor areas, the openwork elements reduce surfaces temperature and mitigate the characteristic glare of smooth surfaces when exposed to sunlight. Openwork walls have an immense sustainability potential in modern tropical buildings: they limit the solar rays' admission, as well as provide an advantageous use of natural light and cross ventilation, but the research on their solar behavior is scarce. In order to obtain suitable levels of solar gain, relationships among shape, proportion, thickness and partitions composing openwork elements must be studied. This research evaluates solar gain in perforated surfaces by defining the "solar applicability range", a property useful to identify intervals of guidance where a perforated pattern shape will present a definite solar gain, giving valuable input in the geometric design of openwork elements and introducing shade performance in the design of openwork walls. Results give geometric guidelines that allow to widen the solar applicability range of a perforation pattern and to define two perforation features that have impact on the solar performance of perforated surfaces: focalization and solar performance shift.