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Sex in the surf zone: the effect of hydrodynamic shear stress on the fertilization and early development of free-spawning invertebrates. Stanford University
hydrodynamic shear stress free-spawning invertebrates
2015/11/12
Sex in the surf zone: the effect of hydrodynamic shear stress on the fertilization and early development of free-spawning invertebrates. Stanford University。
Residue Placement and Rate, Crop Species, and Nitrogen Fertilization Effects on Soil Greenhouse Gas Emissions
Greenhouse Gases Residue Management Nitrogen Fertilization Crop Species Spatial Variability
2013/3/11
High variability due to soil heterogeneity and climatic conditions challenge measurement of greenhouse gas (GHG) emissions as influenced by management practices in the field. To reduce this variabilit...
变量施肥控制系统PID控制策略（PID Control Strategy of the Variable Rate Fertilization Control System）
变量施肥 控制系统 数学模型
2010/12/29
根据机械动力学原理和电学原理建立了变量施肥控制系统的数学模型，为控制系统的设计、PID参数选择以及控制性能改进提供了理论依据。利用Matlab/Simulink动态仿真工具构建了直流伺服电动机驱动无级变速传动机构的仿真模型，采用临界比例度法对系统的PID参数进行整定，获得了反映系统性能的仿真曲线，仿真和试验验证结果表明，PID控制策略提高了控制系统的跟踪性能和抗干扰性能。
在国内外相关研究的基础上，对木灰这类典型生物质灰的组成和物理、化学特性进行分析，并阐述了木灰作为肥料施用后对作物、土壤表层植被、土壤微生物群和环境各方面的影响。木灰的K含量不高，但是具有较高的pH值，对酸性土壤的改良作用很明显。pH值的提高可以改变土壤中微生物结构，促进微生物的活动，增加土壤肥力。同时，木灰还具有大量元素富集的特点，施用后会改变土壤中元素的构成，增加土壤中N、K等植物生长必需元素的...
一种变量施肥技术的实现及其台架试验（Design and Experiment of a Variable Rate Fertilization Control System）
变量施肥 控制系统 台架试验
2010/12/28
采用单片机作为CPU，结合压力传感器、AD采集卡以及伺服电动机，设计了变量配肥施肥控制系统，同时设计了与硬件配套的上位机软件，用来采集数据与发送命令，台架试验表明，该系统能实现变量配肥施肥，且结构简单，施肥精度达到95%。
深施型液态施肥装置的设计与试验（Design and Experiment on Liquid Fertilizer Device of Deep-fertilization）
液态肥 施肥量 损失率
2009/5/22
在分析液态肥深施特点的基础上，针对深施过程中人工开沟、覆埋难度大的问题，设计了一种可深施液态肥的装置。对此装置的施肥性能进行了二次旋转正交试验，利用Design-Expert 6.0.1软件分析，获得了液泵压力、喷口直径、土槽台车前进速度和截止阀开度之间交互作用对施肥损失率的影响。最终确定了液态施肥装置的最佳工作参数为：液泵压力0.2MPa、喷肥针喷口直径3mm、土槽台车前进速度0.975m/s和...
深施型液态施肥机扎穴机构优化设计（Optimization Design on Pricking Hole Mechanism of Deep-fertilization Liquid Fertilizer Applicator）
液态施肥机 扎穴 椭圆齿轮 仿真 优化 设计
2010/5/5
为实现液态施肥机高速作业，设计了一种结构简单、运动平稳的椭圆齿轮行星系作为液态施肥机的扎穴机构。对该机构进行运动学分析，建立了数学模型，以穴距200mm和入土深度120～150mm为寻优目标，应用Visual Basic 6.0软件编程得出满足机构运动要求的最优参数范围为：喷肥针尖和行星轮轴连线与行星架的初始夹角-45°～-40°、行星架初始角位移40°～50°、喷肥针尖与行星轮轴心距离280～3...
Effects of Fertilization and Clipping of Phlomis fruticosa L. on a Phryganic Ecosystem: The Case of Thesprotia, Northwest Greece
N+P fertilization clipping Phlomis fruticosa L. phryganic ecosystems rangelands
2009/1/12
This study examined the effectiveness of various shrub control treatments (N+P fertilization, clipping of Phlomis fruticosa and clipping combined with N+P fertilization), to reduce shrub cover and enc...
Effects of Fertilization and Clipping of Phlomis fruticosa L. on a Phryganic Ecosystem: The Case of Thesprotia, Northwest Greece
N+P fertilization clipping Phlomis fruticosa L. phryganic ecosystems rangelands
2009/1/13
This study examined the effectiveness of various shrub control treatments (N+P fertilization, clipping of Phlomis fruticosa and clipping combined with N+P fertilization), to reduce shrub cover and enc...
Short Communication: Seasonal Effects on Development of Bovine Embryos Produced by In Vitro Fertilization in a Hot Environment
in vitro fertilization heat stress seasonality
2008/8/4
The objective of this study was to determine if season affected the production of in vitro-derived bovine embryos from oocytes of cattle in a subtropical environment. Ovaries 75% beef cattle, includin...