玉米精准作业系统中土壤养分空间变异图的制作技术研究

玉米是我国的三大粮食作物之一,同时也是我国农业生产中的支柱产业。玉米的生产同时受许多不确定因素的影响。长期以来,盲目施肥、过量施肥现象普遍,不仅造成农业生产成本增加,而且带来严重的环境污染,威胁农产品质量安全。利用地理信息系统地统计分析模块,分析和绘制玉米核心技术示范区和辐射推广区的土壤养分空间变异图,探讨土壤养分的空间变异规律,为精准变量施肥提供基础数据。     

多个软件结合运用进行国家重点公益林成果图编制

论述利用Erdas Imagine、Are／info、Areview等软件综合运用、优势互补制作林业图件的必要性及优势．详述了根据国家重点公益林成果图的编制要求,运用多个软件进行制图的流程、步骤和方法．     

Autumn Irrigation Alerted the Geochemistry of Groundwater in Hetao Irrigation District：Take Yichang Irrigation District as an Example北大核心CSCD

【Objective】Surface infiltration could change biogeochemical reactions in groundwater thereby alerting its chemical compositions. The aim of this paper is to investigate the responsive change in chemical composition of groundwater to infiltration following the autumn irrigation in irrigation districts.【Method】The experiment was conducted in Hetao Irrigation District, during which we measured the change in concentration of Na+, K+, Ca2+, Mg2+, SO42-, Cl-, HCO3- and CO32- and then statistically analyzed them.【Result】The irrigation increased the concentration of Cl-, SO42-, KNa, Mg2 and HCO3-, but slightly reduced the concentration of Ca2+. The TDS was higher in south and lower in north of the irrigation district. The Piper diagram showed that the Cl-Na was the dominant groundwater type, accounted for 75% and 61% of the studied area before and after the irrigation respectively. Irrigation turned groundwater in 16.7% of the studied area to Mg-SO4-Cl type. The Gibbs model and ion proportional coefficient diagram revealed that the chemistry of groundwater in the studied region was mediated by evaporation, weathering and leaching of silicate and evaporite, and is independent of precipitation. 【Conclusion】The mean TDS in the groundwater increased by 32.9% after the autumn irrigation, indicating the impact of soil leaching. Improving drainage after the autumn irrigation is hence essential. © 2019 Journal of Irrigation and Drainage. All rights reserved.     

Development of a stand density management diagram for Santalum album plantations in Karnataka,India

Stand density management diagrams are average stand-level models that graphically display the relationship between stand yield, density, height and diameter throughout the various stages of forest development in even-aged stands. These are useful tools for designing, displaying and evaluating alternative density regimes in even-aged forest ecosystems to achieve a desired future condition. In this paper, we present a stand density management diagram constructed for sandalwood stands in Karnataka state of India. The relationship between stand density, dominant height, quadratic mean diameter, relative spacing and stand volume is exhibited in one graph. The relative spacing index was used to characterise the growing stock level. Two equations were fitted to the data collected from 19 sample plots measured annually for three years: one relates quadratic mean diameter with stand density and dominant height, whereas the other relates total stand volume with quadratic mean diameter, stand density and dominant height.     

Fishway with two entrance branches: Understanding its performance for potamodromous Mediterranean barbels

Many fish passes have been built across the world in recent years. This study analyses the performance of a modified type of pool and weir fishway with two access branches, using passive integrated transponder telemetry. A circum‐Mediterranean barbel, Luciobarbus bocagei (Steindachner, 1864), was chosen as the target species. Both hydraulic values (flow and volumetric energy dissipation) and biological parameters (attraction, entrance and passage success) were measured in the fishway, these being related to the environmental variables affecting upstream fish movement. Flow discharge, water temperature and atmospheric pressure were important for fish entering the fishway. There was no preference between path routes, even though the main discharge was concentrated in the turbine channel. This type of fishway design could be an alternative for the conservation of fish populations where multiple fish approach options are possible.     

温室不同种植模式番茄冠层气候特征及对产量的影响研究

[目的]以樱桃番茄为试验材料,研究温室平面种植模式和立体阶梯种植模式番茄冠层气候特征及对产量的影响.[方法]采用立体阶梯种植模式和平面栽培模式,并进行比较.[结果]立体阶梯种植模式作物冠层的平均光照强度、平均气温均比平面种植模式分别高12;、11;,而相对湿度低20;;立体阶梯种植模式相对平面种植模式产量增加了25;,单果重增加了21;,落花率减少了17;,果实含糖量上升了1;.[结论]立体阶梯种植模式改善了番茄冠层气候环境,实现了高产优质的目的.     

Incipient motion design of sand bed channels affected by bed suction

Seepage through sand bed channels in a downward direction (suction) reduces the stability of particles and initiates the sand movement. Incipient motion of sand bed channel with seepage cannot be designed by using the conventional approach. Metamodeling techniques, which employ a non-linear pattern analysis between input and output parameters and solely based on the experimental observations, can be used to model such phenomena. Traditional approach to find non-dimensional parameters has not been used in the present work. Parameters, which can influence the incipient motion with seepage, have been identified and non-dimensionalized in the present work. Non-dimensional stream power concept has been used to describe the process. By using these non-dimensional parameters; present work describes a radial basis function (RBF) metamodel for prediction of incipient motion condition affected by seepage. The coefficient of determination, R² of the model is 0.99. Thus, it can be said that model predicts the phenomena very well. With the help of the metamodel, design curves have been presented for designing the sand bed channel when it is affected by seepage.     

基于荧光标记SSR的CID法快速鉴定福建茶树品种

茶树品种真实性鉴定是茶树种质资源研究的重要组成部分,是茶树品种知识产权保护的前提。在茶树基因组上按照均匀分布的原则选择45个SSR标记合成荧光标记引物,利用这些标记引物对54个福建无性系茶树品种进行PCR扩增,标记基因型分型后进一步筛选出9个SSR标记核心引物。这批核心引物的多态性信息含量(Polymorphism information content,PIC)均大于0.5,等位位点数在3~5之间,基因型数在5~10之间,属于高度多态性引物且方便进行基因型数据统计,适宜用来进行无性系茶树品种的真实性鉴定。利用其中的6个标记核心引物建立了54个福建无性系茶树品种的品种鉴别图(Cultivar identification diagram,CID),该CID能直观地提供对其中任意品种进行鉴定所需要的标记引物以及相应的标记基因型,且能够方便地进行扩容以用来对更多的无性系茶树品种进行真实性鉴定。利用该方法对无性系茶树品种进行真实性鉴定,操作方便、快速准确、稳定性高、实用性强。本实验所获得的茶树品种鉴定图(CID)对茶树品种知识产权保护,以及促进茶树品种选育工作健康可持续发展具有重要的意义。     

The modeling and simulation of a new USBCAN bus converter in Stateflow

The USBCAN bus converter is a connector of USB bus and CAN bus.It is difficult to judge whether the device works well or not and meets design requirement or not by ordinary ways.Regarded the Matlab/Simulink/Stateflow toolbox as the platform,the model of a USBCAN bus converter is established.The model of the bus converter is tested and verified in the Matlab/Simulink simulation environment.The results of the simulation analysis show the model is suitable for simulating the working state of the device.A new simulation and judging method for bus converters is proposed.     

基于B/S模式的实验室预约系统UML建模与研究

UML作为一种面向对象的标准建模语言,在信息管理系统的建模领域得到了广泛的应用。概述了UML中多种模型图的使用方法和适用范围,重点分析了UML系统建模的主要过程和特点,并以一个实验预约系统为例详细介绍了系统用例模型、静态模型和动态模型的设计过程。