气液叉流下受热液膜的热质传递特性

采用VOF两相流模型研究了气液叉流条件下受热液膜热质传递特性,在模型中添加了表面张力源项和气液相间传质源项.为了验证所建立模型的可靠性,采用非接触式红外热成像测温方法,进行了相应的气液叉流试验.对叉流条件下受热液膜热质传递过程进行了试验和模拟计算,结果显示无量纲壁面温度计算结果与试验结果吻合很好.应用所建立的模型,模拟计算并分析了表面张力、固液接触角、液膜流量等因素对液膜流动侧形和热质传递性能的影响,结果表明：在其他参数保持不变的情况下,表面张力从0.014 N／m增大到0.072 N／m的过程中,液膜覆盖面积由82.7％减小到73.2％;固液接触角从30°增大到60°的过程中,液膜覆盖面积由80.6％减小到69.4％;液膜流量越小,液膜厚度越小,越有利于液膜的蒸发;相反,较高的液膜流量会使液膜厚度增大,阻碍了液膜蒸发,从而使外掠过液膜的单位体积空气含湿量减小.     

现代居住空间绿化装饰艺术设计初探

现代居住空间的绿化装饰是室内环境艺术设计的重要组成部分。该文从分析现代居住空间的环境特点人手,重点论述了现代居住空间绿化装饰的理论基础及美学原理,并对不同居住空间的绿化装饰类型进行了系统阐述及典型设计,以期为室内环境艺术设计及现代家居生活提供参考。     

冲击条件对原木孔洞缺陷检测效果影响的研究

应用摆锤敲击装置,在实验室条件下研究冲击条件对原木内部孔洞缺陷检测效果的影响。摆锤冲击装置能以不同的速度敲击测试传感器,得到扰动信号在试样内的平均传播速度及原木孔洞缺陷区域的识别质量系数。研究结果表明,适当提高摆锤冲击速度,能够提高原木孔洞缺陷的检测效果。     

The Unloading Effect of Rock Samples and the Quality Evaluation of Engineering Rock Masses

For most evaluating methods of engineering rock mass, the integrality index is an important assessment factor. However, sometimes the value of integrality index would be more than 1.0 because of unloading effect of rock samples and differentia of frequency between the measurements of rock samples and rock mass. In order to solve this problem, unloading index and frequency correcting coefficient were put forward to revise the integrality index. Moreover, the BQ evaluating method proposed in the national standard (GB 50218-94) was improved with the revised method. With the case study of the project of water sealed underground oil tank in Huangdao, it was found that the quality of rock mass in the site was grade I or II.     

Experimental Analysis of Construction Time Space Effect for Large Span and Flat Multi Arch Tunnel

For the large span and flat, together with the interaction effect of construction and disturbance of surrounding rock, the mechanical of large span and flat multi arch tunnel is very complicated, and the time space effect is different from that of two lane multi arch tunnel or separated tunnel. Adopting the “CTSSSRH”, the 3 D dynamic process of the tunnel construction was simulated. Analyzing the rule of surrounding rock displacement and stress with excavation, the time space effect of large span and flat multi arch tunnel was proposed.     

Spatial structure of deciduous forest stands with contrasting human influence in northwest Spain

Five contrasting deciduous forest stands were studied to characterize the spatial structural variability in human-influenced forests. These stands are representative of cultural forest types widely represented in western Europe: one plantation, two coppices, one wood-pasture forest and one high forest stand. All stems with DBH > 5 cm were measured and mapped, and stem DBH distributions, spatial structure of DBH, spatial point patterns and spatial associations were analysed. Spatial autocorrelation for DBH was calculated with Moran’s I correlograms and semivariograms. Complete spatial randomness hypothesis for spatial point patterns, and both independence and random labelling hypotheses for spatial associations were analysed using Ripley’s K function. The results showed that tree sizes were conditioned by particular former management systems, which determined unimodal symmetric, positively skewed or compound DBH distributions. Spatial structure was more complex when human influence became reduced. Coppice stands showed clumped spatial patterns and independence among size classes, as a consequence of sexual and vegetative establishment of new stems in open areas. The largest clumping intensity was observed in the wood-pasture with an intermediate disturbance frequency and low inter-tree competition. The high forest stand displayed spatial traits consistent with the gap-dynamics paradigm, such as clumping of smaller trees, random arrangement of larger trees, negative association between juveniles and adults, and high structural heterogeneity. It can be expected that after cessation of human interference, coppices and wood-pastures would evolve to a more heterogeneous structure, probably with a higher habitat and species diversity.     

榕属植物在园林空间构建中的应用

榕属（Ficus）植物作为岭南园林中最具特色的一类植物,通过其各种生物学特性,在植物空间的构建中发挥着重要作用。文章通过对广州及附近城市园林绿地的调查,阐述了榕属植物在园林空间构建中的作用和影响因素,总结出榕属植物通过孤植、列植、垂直绿化、空间点缀、形成空间序列等形式,构成植物空间。并对空间构建过程中,榕属植物与其他造景要素的配合以及榕属植物独特的文化内涵进行了讨论。     

城市绿地信息提取中的遥感影像阴影校正

建筑物阴影会对城市绿地产生遮蔽,从而影响城市绿化的遥感调查结果。该文利用乌鲁木齐的QuickBird遥感数据,采用面向对象的技术对遥感影像进行阴影检测,并对阴影区域进行灰度补偿,改进了阴影区域的信息,然后采用面向对象的技术对阴影校正后的影像进行绿地信息提取。结果表明:该方法检测高分辨率遥感影像的阴影区域简单易行;通过灰度补偿可以有效地恢复阴影区域的信息,从而提高城市绿化遥感调查的准确性。      

基于灰色系统的地下水动态研究

为了深入探求地下水动态变化规律,以陕西洛惠渠灌区实测数据为例,首先采用改进的灰色斜率关联法,对灌区自然-人工-生物条件下地下水动态敏感性因子进行研究,分析了各因子与地下水埋深的关系,并运用灰色动态模型对敏感因子进行灾变预测.结果表明:蒸发量是影响该灌区地下水动态的主要因子,而各因子之间相互作用影响,形成了复杂条件下的耦合关系;灰色动态模型对蒸发量的灾变预测精度较高,完善模型系统.将灰色系统理论应用到灌区地下水动态评价中是切实可行的,是对传统地下水动态研究方法的补充与完善,可为灌区管理和调控提供一定的依据.     

晋西黄土丘陵沟壑区降雨地形分布规律研究

通过对不同高程（1158m、1270m、1341、1407）,不同坡向（峁顶、阳坡、阴坡、阳沟坡、阴沟）情况下20个观测点的降雨量监测,经过分析研究表明：对于丘陵沟壑区的山地降雨,在不考虑坡向影响的情况下,降雨量基本随着高程变化规律为,先增加后减少;在同一高程,不同坡向情况下降雨量的分布规律为：阴沟坡>阴坡>峁顶>阳沟坡>阳坡,即阴坡（背风坡）>阳坡（迎风坡）;不同高程情况下亦是如此。