省级农业科学院系统农业信息机构职能分析

对国内25家省级农业科学院系统农业信息机构的工作职能进行了统计分析,主要服务方式包括：网络信息资源收集发布,科技期刊编辑发行,声像产品制作发行,文献资源收集整理提供服务以及农业发展战略研究方案制定、农业工程设计等。     

综合评判与经营管理

该文系统介绍了“主因素突出型”综合评判模型,“加权平均型”综合评判模糊,并把其应用于市场分析、信息反馈、经济决策,充分展示了综合评判模型在经济生活中的强大生命力。     

The Red Edge Parameters of Different Wheat Varieties Under Different Fertilization and Irrigation Treatments

The dynamics of red edge parameters at different growth stages of wheat canopy was studied.The red edge position moved to the longer wavelength from erecting stage to heading stage, and returned to the original wavelength direction from grain-filling stage to maturity stage. The leaf total nitrogen content (LTN)is positively related to red edge amplitude (d λ red) and NIR platform amplitude (d λNIRP) and the correlation coefficient improved as growth stage extended. The chlorophyll content (TChl) is negatively related to d λ red from erecting stage to the elongation stage, and positively related to d λ red from heading stage to milky maturity stage. TChl is also positively related to d λNIRP. The leaf area index (LAI) is positively related to d λ red and d λNIRP, and the correlation coefficient improved as growth stage extended. It was concluded that d λ red and d λNIRP can be used as the indicators of winter wheat growth state, and guide the fertilization and irrigation decision making. The λNIRP is suitable for derivation of LTN, the d λ red for TChl, and the d λ red or d λNIRP for LAI.     

柿AFLP银染技术体系的建立

通过对各主要影响因素的研究,建立了适于柿AFLP分析的银染技术体系:酶切体系20μL总体积中含纯化后的DNA450ng,EcoRI和MseI各3U,37℃酶切4h;酶切完成后加入连接液,37℃连接10h(或过夜),然后65℃变性10min;连接产物稀释5倍用于预扩增,预扩增体系中EcoRI和MseI引物均不含选择性碱基;预扩增产物稀释5倍用于选择性扩增,选择性扩增体系中EcoRI和MseI引物均含3个选择性碱基,选择性扩增完成后,加入10μLLoadingbuffer,95℃变性10min,立即冰浴;取6 5μL变性后的选择性扩增产物在6%变性聚丙烯酰胺凝胶上电泳,电泳完毕后,对胶板进行固定、脱色、水洗、银染、冲洗、显影、定影及干燥等银染程序。     

西南大西洋阿根廷滑柔鱼中心渔场预报的实现及验证

提高渔情预报技术是渔场学的重要研究内容,地理信息系统等高新技术在渔情预报中的应用日益增多。本文根据我国在西南大西洋海域生产的鱿钓统计数据,结合海洋环境因子,利用栖息地指数方法构建了西南大西洋阿根廷滑柔鱼中心渔场预报模型,自主研发了软件预报系统。同时,利用实时的表温、叶绿素和海面高度距平值等海洋环境因子,对2009年生产作业情况进行了验证。分析认为,实际作业渔场基本上都分布在栖息地指数为0.5以上的海域,1-4月份中心渔场预报准确率为57%～74%,平均准确率为68.29%。研究认为,栖息地指数模型可较为准确地用来预测阿根廷滑柔鱼中心渔场,同时依靠地理信息系统等技术实现了中心渔场预报的智能化。研究亮点:利用栖息地指数方法构建了基于表温、叶绿素和海面高度距平均值的阿根廷滑柔鱼中心渔场预报模型,并自主研发了软件预报系统。根据2009年1-4月实时的海洋环境和生产实际情况,对中心渔场进行了验证比较,其预报平均准确率达到68.29%。     

基于神经网络的水稻产量预测模型

研究不同水分处理所得的作物实际产量,建立前馈神经网络模型,得到不同土壤含水量时的旱作水稻预测经济产量,模型通过学习,使误差减小到0.1。     

Assessment of Land Suitability Potentials for Selecting Winter Wheat Cultivation Areas in Beijing, China, Using RS and GIS

It is very important to provide reference basis for winter wheat quality regionalization of cultivation area. The aim of this article was based on factors affecting wheat quality and setting realistic spatial models in each part of the land for assessment of land suitability potentials in Beijing, China. The study employed artificial neural network (ANN) analysis to select factors and evaluate the relative importance of selected environment factors on wheat grain quality. The spatial models were developed and demonstrated their use in selecting the most suitable areas for the winter wheat cultivation. The strategy overcomes the non-accurate traditional statistical methods. Satellite images, toposheet, and ancillary data of the study area were used to find tillable land. These categories were formed by integrating the various layers with corresponding weights in geographical information system (GIS). An integrated land suitability potential (LSP) index was computed considering the contribution of various parameters of land suitability. The study demonstrated that the tillable land could be categorized into spatially distributed agriculture potential zones based on soil nutrient and assembled weather factors using RS and GIS as not suitable, marginally suitable, moderately suitable, suitable, and highly suitable by adopting the logical criteria. The sort of land distribution map made by the factors with their weights showed more truthfulness.     

Exploring the Feasibility of Winter Wheat Freeze Injury by Integrating Grey System Model with RS and GIS

Winter wheat freeze injury is one of the main agro-meteorological disasters affecting wheat production. In order to evaluate the severity of freeze injury on winter wheat systematically, we proposed a grey-system model (GSM) to monitor the degree and the distribution of the winter wheat freeze injury. The model combines remote sensing (RS) and geographic information system (GIS) technology. It gave examples of wheat freeze injury monitoring applications in Gaocheng and Jinzhou of Hebei Province, China. We carried out a quantitative evaluation method study on the severity of winter wheat freeze injury. First, a grey relational analysis (GRA) was conducted. At the same time, the weights of the stressful factors were determined. Then a wheat freezing injury stress multiple factor spatial matrix was constructed using spatial interpolation technology. Finally, a winter wheat freeze damage evaluation model was established through grey clustering algorithm (GCA), and classifying the study area into three sub-areas, affected by severe, medium or light disasters. The evaluation model were verified by the Kappa model, the overall accuracy reached 78.82% and the Kappa coefficient was 0.6754. Therefore, through integration of GSM with RS images as well as GIS analysis, quantitative evaluation and study of winter wheat freeze disasters can be conducted objectively and accurately, making the evaluation model more scientific.     

遥感在海洋渔业中的应用与研究进展

随着遥感技术的发展,遥感在海洋渔业中的作用逐渐被人们所认识,其在海洋渔业中的应用不断深入,应用领域也不断被拓展。作者综述了遥感在海洋鱼群侦察、海洋环境要素与海洋鱼类地理分布关系的研究、海洋渔业资源的变动及评估、海洋渔业管理与安全等4个方面的应用,并对其存在的问题和取得的进展进行了归纳总结。     

Improved Signal Detecting Algorithm for Burst Communication

Signal detecting is the first task for Burst communication. The paper proposes an improved double sliding window algorithm to detect burst signal based on the feature of preamble sequence. Additionally, theory analysis and computer simulation of the improved algorithm are also made in several typical channels. At last, the algorithm is realized with FPGA, and the result indicates that the improved algorithm can detect burst signal only within the time of 6 symbols, obviously improving the capability of signal detecting algorithm.