Comparing surface erosion processes in four soils from the Loess Plateau under extreme rainfall events

This research aims to improve erosion control practice in the Loess Plateau, by studying the surface erosion processes, including splash, sheet/interrill and rill erosion in four contrasting soils under high rainfall intensity (120 mm h⁻¹) with three-scale indoor artificial experiments. Four contrasting soils as sandy loam, sandy clay loam, clay loam and loamy clay were collected from different parts of the Loess Plateau. The results showed that sediment load was significantly impacted by soil properties in all three sub-processes. Splash rate (4.0–21.6 g m⁻²∙min⁻¹) was highest in sandy loam from the north part of the Loess Plateau and showed a negative power relation with the mean weight diameter of aggregates after 20 min of rainfall duration. The average sediment load by sheet/interrill erosion (6.94–42.86 g m⁻²∙min⁻¹) was highest in clay loam from middle part of the Loess Plateau, and the stable sediment load after 20 min showed a positive power relation with the silt content in soil. The average sediment load increased dramatically by rill and interrill erosion (21.03–432.16 g m⁻²∙min⁻¹), which was highest in loamy clay from south part of the Loess Plateau. The average sediment load after the occurrence of rill showed a positive power relation with clay content and a negative power relation with soil organic matter content. The impacts of slope gradient on the runoff rate and sediment load also changed with soil properties. The critical factors varied for different processes, which were the aggregate size for splash erosion, the content of silt particles and slope gradient for sheet/interrill erosion, and the content of clay particles, soil organic matter and slope gradient for rill erosion. Based on the results of the experiments, specific erosion control practices were proposed by targeting certain erosion processes in areas with different soil texture and different distribution of slope gradient. The findings from this study should support the improvement of erosion prediction and cropland management in different regions of the Loess Plateau.     

对咸阳市畜禽粪便污染环境问题的初探

对咸阳地区的畜禽养殖状况,畜禽粪便的污染程度,畜禽粪便治理的现状与存在的问题,提出了治理的措施及治理后的前景,以期为政府部门在研究制定咸阳市规范时提供考虑。     

高职学校畜牧兽医专业实验室管理

为了加强高职院校实验室管理,通过制订和完善实验室管理制度,如实验室技术人员管理、仪器设备的采购和实验用药品的管理、对学生的管理、创新实验项目的实验室管理、实验室网络平台和实验室对外技术服务的管理、病原微生物的保存与处理、病死动物的无害化处理、实验室应急事件处理等措施,实现统筹规划和资源共享,培养学生的实验兴趣,使学生初步掌握畜牧兽医专业实验研究的基本方法和实验操作的基本技能,促进实验室的科学化、规范化、制度化的管理,以达到全面提升学生实践操作技能的目的。     

出口兔肉备案养殖场追溯体系的建立

从保证动物源性食品安全的角度论述了建立养殖场追溯体系的必要性,以出口兔肉备案养殖场为例,对建立追溯体系的步骤进行了四个方面的探讨。养殖场在设施合理、制度健全的前提下,确定追溯信息的深度、广度和精确度,并作好信息衔接和代码标识,才可使追溯体系有效实施。同时对追溯体系的应用和发展趋势做了基本论述。     

基于校园网环境下机房总管Ⅱ系统的设计与实现

本文介绍了一种基于校园网实现机房自动化管理系统的设计思路与实现方法.该系统用助于提高机房的管理水平、使用效率与管理质量.     

基于GIS的农田养分管理与推荐施肥系统设计与开发

针对我国南方农业过于分散的农田经营管理体系和施肥现状,以浙江绍兴东湖镇独树村为研究区域,应用信息技术、系统养分研究法和推荐施肥模型,研制和开发出适于南方土壤及作物体系的土壤养分管理和决策信息系统平台,实施田块或田畈为基本单元的村级信息化农田养分全程管理,进行推荐施肥,初步应用结果表明,推荐施肥示范方各农户水稻产量大部分达到每亩450～500公斤以上.     

目录直读图片管理系统的设计及实现

目录直读图片管理系统是一个新型的图片管理系统.许多非计算机专业的电脑爱好者在使用以往的图片管理软件时,大多都只能进行自己能力范围内的修改,在数据库的使用上则出现了不少问题.目录直读图片管理系统的最大特点就是只有一个单文件,没有数据库,这样就巧妙的解决了非计算机专业电脑爱好者所头疼的问题.本文着重阐述了目录直读图片管理系统中,图片管理的实现策略、关键技术、实现方案等.     

图书馆隐性知识的管理与挖掘

隐性知识是图书馆的宝贵资源.本文在解析隐性知识涵义和特点的基础上,阐述了图书馆隐性知识的作用,分析了图书馆隐性知识管理存在的障碍,提出了图书馆隐性知识挖掘的基本策略.     

中国知识密集型电子商务发展的制约因素分析

结合中国社会的实际情况,电子商务作为知识密集型服务,其发展之制约因素分为外部和内部两类,本文深入剖析电子商务发展中国内环境、电子商务业务中个人消费者、传统企业以及电子商务企业存在的知识管理方面的弊端,以引发相关部门、企业及个人的思考.     

Weather-Centric Rangeland Revegetation Planning

Invasive annual weeds negatively impact ecosystem services and pose a major conservation threat on semiarid rangelands throughout the western United States. Rehabilitation of these rangelands is challenging due to interannual climate and subseasonal weather variability that impacts seed germination, seedling survival and establishment, annual weed dynamics, wildfire frequency, and soil stability. Rehabilitation and restoration outcomes could be improved by adopting a weather-centric approach that uses the full spectrum of available site-specific weather information from historical observations, seasonal climate forecasts, and climate-change projections. Climate data can be used retrospectively to interpret success or failure of past seedings by describing seasonal and longer-term patterns of environmental variability subsequent to planting. A more detailed evaluation of weather impacts on site conditions may yield more flexible adaptive-management strategies for rangeland restoration and rehabilitation, as well as provide estimates of transition probabilities between desirable and undesirable vegetation states. Skillful seasonal climate forecasts could greatly improve the cost efficiency of management treatments by limiting revegetation activities to time periods where forecasts suggest higher probabilities of successful seedling establishment. Climate-change projections are key to the application of current environmental models for development of mitigation and adaptation strategies and for management practices that require a multidecadal planning horizon. Adoption of new weather technology will require collaboration between land managers and revegetation specialists and modifications to the way we currently plan and conduct rangeland rehabilitation and restoration in the Intermountain West.