Flow patterns and gas fractions of air–oil and air–water flow in pipe bends

An experimental study of two-phase flow in a 180° pipe bends with 0.016, 0.022 and 0.03 m and the curvature radii of 0.11, 0.154, 0.21 m, respectively have been carried out. The experiments were conducted under the input superficial phase velocity: air from 0.038 to 5.4 m s⁻¹, water from 0.018 to 0.92 m s⁻¹ and oil from 0.014 to 0.92 m s⁻¹. The conducted research involved the observation of the forming flow patterns and determination of average volumetric in situ gas fraction. On the basis of the results of experimental flow map was created for gas–liquid flow and a method of calculating gas fractions was established.     

滨湖住区形态研究与实践

深入分析了目前城市滨湖地区发展中存在的主要问题,结合岳阳中航·翡翠湾规划设计实例,提出了一种基于国情较为合理的滨湖住区形态,改善了人居环境,使滨湖景观更加完美。     

气藏采收率影响因素研究与启示——以靖边气田A井区为例

以鄂尔多斯盆地靖边气田A井区为例，采用单因素相关分析和数值模拟方法，对比研究了井网控制程度、储层物性及地层废弃压力对气藏采收率影响及其主次关系。结果表明，井网控制程度是影响采收率的首要因素，井网控制程度每增加10%，采收率提高8.5%；渗透率是影响采收率的重要因素，渗透率每增加10%，采收率平均增加6%；废弃压力对采收率亦有较大影响，废弃压力每降低10%，采收率可提高1.6%。三者对采收率影响综合排序为：井网控制程度>储层物性>废弃压力。分析认为，渗透率是储层固有属性，很难从根本改变；而废弃压力受井口外输压力和增压开采成本制约，降低幅度有限。因此，优化井网及增加井网控制程度是提高气藏采收率的有效途径。研究成果具有实践意义，可为改进气田开发方式和提高气藏采收率提供参考。     

Experimental Research on Gas-Liquid Two-Phase Spiral Flow in Horizontal Pipe

In view of the importance of gas-liquid two-phase spiral flow and the few research reports at home and abroad,the gas-liquid two-phase spiral flow patterns have been researched in a horizontal pipe with different parameters investigated by means of observation and a high-speed camera.Since the appearance of spiral flow makes the distribution of twophase flow more complicated,the flow patterns appearing in the experiments were divided into the Spiral Wavy Stratified Flow(SWS),the Spiral Bubble Flow(SB),the Spiral Slug Flow(SS),the Spiral Linear Flow(SL),the Spiral Axial Flow(SA),and the Spiral Dispersed Flow(SD) by the observations and with reference to the predecessors’ research achievements.A flow pattern map has been drawn up.The influence of velocity,vane angle and vane area on flow pattern conversion boundary and pressure drop has been studied,with a solid foundation laid for the future research work.     

A star pattern recognition algorithm for cameras with large FOV

In most large field of view (FOV) observations, the distortion problem is inevitably and significantly more serious than in small FOV ones. In the circumstances, many traditional star identification approaches are not able to efficiently identify stars any more. In order to deal with this problem, we put forward a star identification method that is less sensitive to distortion. The method first processes stars in the central area of the image, using traditional identification logic, and then applies the region growing strategy to enlarge the identified regions iteratively until the entire image is covered. The performance of the new scheme is analysed in the presence of both simulated data and real data. The results show that the proposed algorithm has the advantage of speed, and the strategy of regional extension can efficiently identify stars in large FOV images compared with other existing algorithms.     

谈装饰工程施工中各种砖的排砖方法

为了避免装饰工程施工中因排砖方法不正确影响工程观感效果,对外墙面砖、室内地板砖、卫生间地板砖的排砖方法进行阐述,以供装饰工程施工人员参考借鉴。     

苏州留园昆曲观演空间研究

江南园林昆曲观演空间是园林空间与昆曲艺术长期相互作用的产物,具有极高的文化、艺术和研究价值。文章选择苏州留园内的三处昆曲观演空间,利用文献阅读、实地测绘、场景复原等方法,从尺度意境、空间组合、视线组织和昆曲活动等方面进行分析和解读,探索了园林空间与昆曲活动的具体作用机制。留园内三处昆曲观演空间的物理特征与昆曲活动各有特色,呈现出不同的相互作用关系;昆曲活动和三处昆曲观演空间都具有极高的匹配度,通过长期的磨合形成一致的风格趋向,构成了具有鲜明时代特征的昆曲观演空间。     

An absolute interval scale of order for point patterns

Human observers readily make judgements about the degree of order in planar arrangements of points (point patterns). Here, based on pairwise ranking of 20 point patterns by degree of order, we have been able to show that judgements of order are highly consistent across individuals and the dimension of order has an interval scale structure spanning roughly 10 just-notable-differences (jnd) between disorder and order. We describe a geometric algorithm that estimates order to an accuracy of half a jnd by quantifying the variability of the size and shape of spaces between points. The algorithm is 70% more accurate than the best available measures. By anchoring the output of the algorithm so that Poisson point processes score on average 0, perfect lattices score 10 and unit steps correspond closely to jnds, we construct an absolute interval scale of order. We demonstrate its utility in biology by using this scale to quantify order during the development of the pattern of bristles on the dorsal thorax of the fruit fly.     

Structural failure determination with fuzzy sets

This paper has four objectives. Firstly, modifications are recommended and presented to a well known set of US Army test data representing eleven tests that involve destruction of buried concrete box structures by ground transmitted shock waves. The resultant database is available for failure mode analysis. Secondly, a new approach forfailure mode analysis based on pattern recognition techniques to the structural engineering community is introduced. Thirdly, a comparison is presented of the results of preprocessing, feature extraction, and cluster analysis for failure modes to several previous studies. The objective here is to inform the structural engineering community about data interpretations that can be inferred using this approach; the authors do not claim to have a conclusive or definitive classification of failure modes in these data. Finally, the importance of a priori decisions about data analysis during the planning stages of physical experiments is emphasized by pointing out the many statistical and other uncertainities that are associated with the data being discussed.     

钢筋套筒灌浆连接研究进展

钢筋套筒灌浆连接是当前预制混凝土结构钢筋连接的主要方式。从材料、界面、连接的角度，针对其国内外相关研究成果开展系统分析与总结。结果表明：套筒可为金属、非金属材质(如FRP),锥形套筒的连接性能优于圆柱形的，套筒长度不应短于临界长度，内径越小越有利，壁厚不应小于被连接钢筋直径的1/13,但也不宜过厚；低温、负温灌浆料适用的环境温度分别不超过-5、-10℃,耐高温灌浆料可通过掺入聚丙烯纤维进行制备；灌浆料与钢筋界面的黏结强度主要与灌浆料抗压强度的平方根相关，并受到套筒约束能力、高温作用的显著影响；钢筋套筒灌浆连接受拉失效模式包括套筒外钢筋断裂、灌浆料与钢筋界面黏结失效以及套筒与灌浆料界面黏结失效；荷载类型对钢筋套筒灌浆连接力学性能的影响较小，失效模式转变的关键温度是400℃,灌浆缺陷率不超过20%能确保连接接头的可靠性；界面、钢筋黏结长度对钢筋套筒灌浆连接力学性能的影响显著。基于此，提出全黏结长度和双界面两个概念，以控制钢筋套筒灌浆连接的承载性能与失效模式。同时，提出有待开展的研究：灌浆料的本构关系、率敏感性、热工参数等；受高温作用、侧向约束的影响，灌浆料与钢筋界面的黏结应力-滑移本构关系...