水热法制备钛柱撑蒙脱石及对水体中砷酸根的吸附

采用水热法制备了以四氯化钛为前驱物的钛柱撑蒙脱石，通过X射线衍射、热质量与差热分析和透射电子显微镜等手段对其结构进行表征，并研究其对水体中砷酸根的吸附作用．结果表明，水热法制备未经热处理的钛柱撑蒙脱石由于具有颗粒均匀、晶型完整、良好的稳定性以及高比表面积和表面羟基含量多等特点，对水体中的砷酸根有良好的吸附效果．随着对钛柱撑蒙脱石热处理温度升高，材料对水体中砷酸根的吸附能力呈明显下降趋势。     

魁北克的"存"与"亡" ——关于安妮·布里赛特的《寻求母语:翻译与文化身份》

安妮.布里赛特在其《寻求母语:翻译与文化身份》一文中,从政治与意识形态的角度探讨了魁北克戏剧翻译的研究,肯定了翻译在魁北克身份重构过程中所起到的独特作用。本文试图对此文中布里赛特的翻译思想进行分析和评介,以期对译学研究提供一些启示。     

Multiple seismic discontinuities near the base of the transition zone in the Earth's mantle

The seismologically defined boundary between the transition zone in the Earth's mantle (410-660 km depth) and the underlying lower mantle is generally interpreted to result from the breakdown of the gamma-spinel phase of olivine to magnesium-perovskite and magnesiowustite. Laboratory measurements of these transformations of olivine have determined that the phase boundary has a negative Clapeyron slope and does indeed occur near pressures corresponding to the base of the transition zone. But a computational study has indicated that, because of the presence of garnet minerals, multiple seismic discontinuities might exist near a depth of 660 km (ref. 4), which would alter the simple negative correlation of changes in temperature with changes in the depth of the phase boundary. In particular, garnet minerals undergo exothermic transformations near this depth, acting to complicate the phase relations and possibly effecting mantle convection processes in some regions. Here we present seismic evidence that supports the existence of such multiple transitions near a depth of 660 km beneath southern California. The observations are consistent with having been generated by garnet transformations coupling with the dissociation of the gamma-spinel phase of olivine. Temperature anomalies calculated from the imaged discontinuity depths--using Clapeyron slopes determined for the various transformations--generally match those predicted from an independent P-wave velocity model of the region.     

关于高压子母叶片泵叶片倾角的探讨

针对子母叶片泵叶片倾角的选取影响叶片受力的问题,在考虑了子母叶片泵与普通低压叶片泵的结构及油腔供油原理的不同后,对叶片在吸油区受到的液压力,运动惯性力和接触反力进行建模.取一系列叶片倾角的值,仿真出叶片所受的接触反力变化曲线.经分析,比较得出:在双作用子母叶片泵中,当叶片倾角为零度时,叶片受力状况最佳.     

深圳地铁车站通风与火灾的仿真模拟及现场测试

地铁环境控制通风系统的任务是在正常运行期间为地铁乘客提供舒适的环境,以及在紧急情况下能够迅速疏散乘客并尽可能减少损失．不同城市的气候条件、室外温湿度差异很大,因此选用何种环控方案,应根据客观条件、工程造价、运行效果等方面综合分析．为此,结合深圳地铁一号线的设计情况,建立了地铁车站的物理模型和数学模型,根据设计条件和实验情况确定物理模型的边界条件,分别对地铁车站正常工况和火灾工况进行了模拟分析与现场测试,并将模拟结果与实测结果进行了对比分析,验证了CFD模拟的可行性和正确性．     

A method for the separation and estimation of catechol amines in urine

Zusammenfassung Es wird eine neue Methode zur Bestimmung der Katecholamine im Harn beschrieben. Die Katecholamine werden im Harn acetyliert und die Acetylderivate papierchromatographisch im Bush-?C?-System getrennt. Nach erfolgter Trennung werden die einzelnen Katecholamine mit ?thylendiamin kondensiert und fluorimetrisch untersucht. Eine Spezifit?tserh?hung der Methode durch Anwendung doppelt markierter Isotopen wird in Betracht gezogen.