人畜饮水蓄水池的改进方案——以山东省小钦岛地区为例

无地下淡水的海岛地区,淡水资源十分匮乏,传统的蓄水池难以全面而又安全的满足岛区人民生产生活以及人畜饮水的基本需要。笔者针对传统蓄水池的汲水方法中难以监测水位、水泵置位深度不定等特点,试在传统水泵控制器基础上添加了一些简单的分立元件,达到自动测定水位,并根据水位情况自动调控水泵汲水的目的,以方便对蓄积水的监测和使用。     

涌灌自控系统研究

波涌流灌溉水力自动装置是一种节水、节能、投资省、造价低、性能稳定、无需配套专门的泥沙处理设施、无需外动力的自动系统。装置的动力以渠道内灌溉水本身为动力,即使用渠道内水源,而不需要电、油或太阳能等其它的外动力,省掉了外动力设备,文章介绍该控制装置的设计方法。     

铅酸蓄电池充电电路设计研究

采用恒流充电和恒压充电自动转换,吸取恒流充电和恒压充电的优点,进行了蓄电池充电电路的设计。通过实验证明,该充电电路具有较高的实用性。     

Deriving river networks and catchments at the European scale from medium resolution digital elevation data

The extraction of drainage networks and catchment boundaries from digital elevation models (DEMs) has received considerable attention in recent years and is recognized as a viable alternative to traditional surveys and the manual evaluation of topographic maps. However, most studies have covered limited areas due to the lack of detailed information and/or the lack of highly efficient algorithms. In this paper we present an application that delineates river networks and catchment boundaries across the European continent from a medium resolution (250 m) DEM. We exploit novel algorithms based on the concepts of mathematical morphology and implement a landscape stratification for drainage density.A flow direction grid is computed using an efficient algorithm for the removal of spurious pits. River networks are then derived by imposing a variable threshold for the minimum contributing area needed to form and maintain a channel. This is achieved through a landscape stratification that reflects the ability of the terrain to develop different drainage densities. It is shown that the analysis of environmental characteristics coupled with the analysis of local slope versus contributing area enables river network mapping with a spatially varying drainage density. The result has been validated by comparing the derived data to digital river and catchment data from other sources and with varying scales of observation.     

能见度自动观测和人工目测的对比分析

通过对能见度人工目测和自动观测方法、观测数据和影响因素的分析,认为自动能见度仪观测到的数据更为客观,更具科学性,避免了人为误差,提高了工作效率。为获得准确的观测数据,应对自动观测仪器按照规范及时进行维护。     

能见度自动与人工观测在大雾中的分析与比较

为了探索自动观测能见度代替人工观测可行性,对2013年1月20日08:00~23日20:00一个大雾天气过程从资料应用角度分析。结果表明,自动观测的能见度与人工观测随时间变化趋势是一致的;台站自动观测和道面自动观测2种能见度测量值随时间的演变也一致性较好,差别较小;自动观测的能见度变化与温度露点差的变化是一致的,体现了能见度与相对湿度高度相关性;台站观测和道面观测组成同一能见度观测网,能够很好地反应北京能见度情况,对于预报和服务具有重要作用。自动观测能见度代替是可行的。但由于自动观测数据小于人工观测数据,在天气预报业务中启用自动观测能见度数据后,将大大增加预报大雾以及发布大雾预警的频率,需要调整雾霾天气的有关能见度的发布标准。     

森林面积方法研究

本文通过对遥感图像的处理和光谱特征信息的分析,应用ETM 影像数据和地面调查数据,研究了遥感数据处理技术在植被信息提取中的应用,尝试对高山峡谷区的森林资源调查提出较为完善的计算机图像处理技术和自动分类方法。对道孚县台站林场和麻孜林场地类的分类结果表明:运用TM453波段融合能够达到较好的图像增强效果;运用无监督分类方法提取森林面积能达到较高的分类精度;NDVI比RVI更能突出植被信息和消除山体阴影的影响。     

数学形态学在高分辨率图像土地覆盖分类中的应用

高分辨率影像可以清楚地显示树木房屋等地物细节,但是用基于像元的分类很难将这些细碎的地物融合为通常的土地覆盖分类图。首先对高分辨率影像进行有监分类,再根据有监分类的结果对不同地类进行二值化,运用数学形态学对各地类二值图进行处理,从而得到地类的边界图。通过多组实验表明,数学形态学运用于高分辨率图像土地覆盖分类既保留了图像的地类特征,也快速得到了不同地类的边界。     

自动气象站的运行现状分析及改进建议

利用2003～2010年秦皇岛自动站与人工观测资料,从仪器的原理、观测时间和安置环境的差异,分析了自动仪器和人工仪器的对比观测数据的误差成因,结合实际工作中遇到的自动站故障,总结了自动站容易出现故障的环节和修复的实例,并从实际工作角度对自动站的安装维护及测报软件提出了实用性的工作建议。     

The effects of feeding frequency on waiting time,milking frequency,cubicle and feeding fence utilization for cows in an automatic milking system

Abstract

In this trial, the effects of the forage feeding frequency on the waiting time prior to milking and the cowshed facility utilization by cows milked in an automatic milking unit (AMU) were studied. The feeding frequency was increased from two times per day to six times per day. It was found that the average waiting time per visit for cows using the AMU was reduced from 755 s to 351 s when the feeding frequency was increased. The daily number of visits (milking visit, failed milking visit and not qualified visit) to the AMU was not affected by the change in feeding frequency. It was also found that increasing the feeding frequency had a positive effect on utilization of the cowshed facilities, such as the occupation of the feeding fence, and on the cowshed facilities in the waiting area (cubicles) of the AMU.