Electrochemical deposition of cupric ions for the determination of mass transfer rates to a stepped rotating cylinder electrode

The stepped rotating cylinder electrode (SRCE) geometry has been developed as a simple aid to the practical study of the flow-enhanced corrosion and applied electrochemistry problems commonly observed under conditions of disturbed, turbulent flow. The electrodeposition of cupric ions from an acid sulphate plating bath has been used to characterise differential rates of mass transfer to the SRCE. The variation in thickness of electrodeposited copper films has allowed the mapping of local rates of mass transfer over the active surface of this geometry. Both optical and scanning electron microscopy were used for the examination of metallographic sections to provide a high resolution evaluation of the distribution of mass transfer coefficient. Results are also discussed using the convective-diffusion model in combination with the existing direct numerical flow simulation (DNS) data for this geometry.     

Coupled Crop and Solid Set Sprinkler Simulation Model. II: Model Application

In this work, applications of the coupled solid set sprinkler irrigation and crop model AdorSim introduced in the companion paper are presented. The sprinkler irrigation model is based on ballistic theory, while the crop model is based on CropWat. AdorSim was used to evaluate the effect of sprinkler spacing on seasonal irrigation water use (WU) and crop yield. The most relevant results were related to the characterization of advanced irrigation scheduling strategies. The differences in crop yield and WU derived from irrigating at different times of the day were estimated for two locations strongly differing in wind speed. Irrigation guidelines were established in these locations to relate gross water use and water stress induced yield reductions. Simulations were also applied to estimate adequate wind speed thresholds for irrigation operation. In the experimental conditions, thresholds of 2.0–2.5?m?s?1 proved effective to control yield reductions and to minimize WU.     

Crop Coefficients for Microsprinkler-Irrigated, Clean-Cultivated, Mature Citrus in an Arid Climate

Crop evapotranspiration (ETc) was measured over a clean-cultivated, mature navel orange orchard with microsprinkler irrigation located near Lindsay, California. Hourly mean latent heat flux density was determined as the residual of the energy balance equation with measured net radiation, soil heat flux density and sensible heat flux density estimated using the surface renewal method. The ETc was compared with ETo calculated using hourly weather data and the ASCE-EWRI Penman-Monteith equation. Following pruning and topping of the trees in the spring of 2001, the Kco values slowly increased as the canopy developed in the following season. An average Kco = 0.82 was observed. In the following year, the mean summertime value increased to about Kco = 0.95, and in 2003 and 2004, the summertime value averaged near Kco = 1.00, which is somewhat higher than observed for drip irrigated trees in southwestern Arizona and considerably higher than reported in the widely used Food and Agricultural Organization of the United Nations publications that were based on infrequent surface irrigation.     

Incidence of Land and Physicochemical Composition of Apples on the Qualitative and Quantitative Development of Microbial Flora During Cider Fermentations

Lactic acid bacteria and yeasts were numerated, isolated and identified from ciders prepared with the same variety of apple from apple trees grown on three different lands: silt, siliceous clay and green clay. The land has an incidence on the time (earliness) of ripeness of the apples and on their sugar content and, therefore, on the development of the microbial flora in the ciders obtained from these fruits. The same genera of yeasts and lactic acid bacteria were isolated from the three ciders, except the yeast Candida famata exclusively found in the must obtained from apples grown on silt. At the quantitative level, the highest development of yeasts was observed in the must from the land green clay whereas lactic acid bacteria growth was enhanced in the must from the land siliceous clay.     

考虑右转车干扰的信号交叉口直行车辆轨迹预测

相交道路右转车辆干扰下的直行车辆轨迹扰动现象成为城市道路信号交叉口交通运行的安全隐患,为提高直行车驾驶人对驶入右转车辆的应对能力并做出正确决策,对于直行车辆扰动轨迹的可靠预测至关重要。研究通过将不同状态下的直行车辆轨迹分布特征与相交道路右转车运行信息相关联,在车辆受扰轨迹识别的基础上将碰撞时间（TTC）指标作为输入层加入模型,构建了3层高斯混合-输入输出隐马尔可夫模型（GMM-IOHMM）,提出了一种考虑信号交叉口被交道路右转车对本面直行车作用程度的直行车辆受扰轨迹预测方法。实验结果表明:改进模型相比于传统的隐马尔可夫模型（HMM）在模型训练时能够更好地拟合实际的轨迹数据,且相比于传统的时间序列模型,GMM-IOHMM模型的拟合效果取得较大提升;可将TTC≤4.5 s且偏航角大于2.35°作为直行车辆轨迹扰动的判别标准。轨迹预测结果能够更加准确地判断直行车辆与周围车辆发生冲突的可能性,可作为受扰直行车及同行其他车辆辅助驾驶系统设计的重要依据。     

强化絮凝沉淀以提高乡镇水厂供水能力的研究

在乡镇水厂扩建改造中应用强化絮凝沉淀技术,在不增加占地的情况下提高了产水量和出水效果.通过穿孔旋流絮凝池水流分路改造和添加扰流板组,沉淀池进水整流及斜管、穿孔排泥管更新改造,产水量由2×104m3/d增加到3.8×104m3/d,出水浊度和单位药耗分别下降41.7%和26.5%,每天增加水量的单位投资仅为92.7元/m3.     

西部矿区深部复杂应力环境下开采扰动区松软岩层力学特性

对西部石嘴山一矿38区深部+600m轨道巷开采扰动区进行了全面的工程地质调查.采用MOTIC-BA300POL型偏光显微镜等综合分析了砂岩、泥岩的矿物成分、物理性质、自然状态以及饱和状态下的力学及变形特性.结合现场围岩变形、应力监测与构造异常探测等,研究了深部复杂应力环境下松软岩层力学特性.     

急斜煤层高阶段综放开采扰动区内 "固-液-气"耦合效应研究与应用

急倾斜煤层高阶段综放开采中有可能导致瓦斯积聚而形成新"爆炸源"。顶煤超前注水(或湮水)对开采扰动区(Excavation Disturbed Zone,EDZ)瓦斯等气体迁移规律的影响也许会对安全开采产生耦合效应。利用"固-液-气"模拟实验装置、数值模拟与现场监测,深入分析了急倾斜特厚煤层高阶段综放开采过程中"顶煤-水-瓦斯"三相介质运动演化、耦合作用及迁移规律。     

PIV measurements of the time-averaged flow velocity downstream of flow conditioners in a pipeline

The flow downstream of three different flow conditioners, a tube bundle and two perforated plates, was investigated by measuring the time-averaged, axial velocity component with Particle Image Velocimetry (PIV). The conditioners were exposed to the flow disturbed by a 90° out-of-plane double-bend. The experiments were performed with air flow through a pipeline of 100 mm i.d. and at Reynolds numbers between 100 000 and 200 000. The axial development of the velocity profiles, without and with conditioner, is documented, and the performance of the three devices in conditioning the disturbed flow can be compared. Particular attention is given to the determination of time-averaged velocity values by means of PIV.     

《IUCN基于自然的解决方案全球标准》下的生态保护修复管理对策研究

面对严峻的生态退化与生物多样性丧失形势,中国陆续出台了诸多生态保护修复相关政策,并实施了三北防护林建设、退耕还林还草、全域土地综合整治、山水林田湖草沙一体化保护修复等工程。上述行动取得显著成效的同时也存在项目系统性不强、保护修复措施缺乏针对性、生物多样性改善成效不足、各类行业标准难以协调、管理模式缺乏科学性等一系列问题。在调查梳理已有管理要求的基础上,参照世界自然保护联盟（IUCN）发布的《IUCN基于自然的解决方案全球标准》核心内容,从管理角度梳理中国当前生态保护修复工作主要的瓶颈以及该标准的“本土化”方式,并分别从技术、资金以及项目管理3个方面提出管理策略：1）围绕生态保护修复项目全生命周期建立标准体系;2）建立健全社会资本投入保护修复领域的机制;3）从完善项目评审、加强部门合作、引入适应性管理及确保有效公众参与方面优化项目管理机制。以期为今后生态保护修复领域的政策制定与管理机制优化提供借鉴。