玉米新品种伟科702在商丘市睢阳区高产创建中的主要栽培技术

介绍了玉米新品种伟科702在商丘市睢阳区高产创建的技术路线,并总结了主要栽培技术,如机械化单粒精播技术、化学调控技术、延时晚收技术等,为河南省玉米高产创建提供技术依据。     

Effect of high rates of zinc on several crops grown on an irrigated plainfield sand

Abstract

A field experiment was conducted to determine whether Zn applied for pathogen control could accumulate to a level which would be toxic to snapbeans, cucumbers, or corn. Zinc sulfate (ZnSO₄) was applied at rates varying from 0 to 363 kg Zn/ha on a Flainfield loamy sand to approximate 3, 9, 27 and 81 years of fungicidal treatment.

Even at the high rate of Zn, yields of snapbeans, cucumbers, or corn generally were not reduced. As rates of applied Zn increased, there was a corresponding increase in the level of Zn in the leaf tissue of all crops grown. At the high Zn rate, snapbean and cucumber leaf tissue accumulated over 350 ppm Zn. Available soil Zn was extracted with 0.1N HCl, EDTA, or DTPA. Highly significant correlations were observed between the Zn removed by each extractant and plant tissue Zn, thus, indicating that the various extractants were equally effective in predicting Zn uptake.

Very little downward movement of Zn was observed. Two and one‐half years after application, the Zn had leached to a depth of only 30 cm in the soil profile at the higher Zn rates.

These data indicate that application of Zn‐containing fungicides and bactericides should not cause a Zn toxicity problem on the Plainfield sand in the foreseeable future.     

具二次脉冲效应的单种群动力学模型分析

讨论了一类具脉冲出生与脉冲收获及脉冲投放的单种群动力学模型,利用离散动力系统频闪映射理论,得到了一个生物资源管理控制值的充分条件.     

Cost structure of and competition for forest-based biomass

Abstract

Biomass has become a popular alternative to satisfy expanding energy demand and as a substitute for fossil fuels and phased-out nuclear energy in Europe. The European Union White Paper stipulates that the utilization of biomass shall increase to 1566 TWh by 2010. However it is often overlooked that the forest resources are already, to a large extent, used by the forest industries. When promoting biomass for energy generation the consequences for the forest industries also need to be considered. Sweden is an excellent case study, as there are vast quantities of forest resources, nuclear power is starting to be phased out, there are restrictions on expanding hydropower and the political desire exists to “set an example” with respect to carbon dioxide emissions. This paper attempts to estimate and analyse the supply of two types of forest resource, namely, roundwood and harvesting residues derived from final harvesting and commercial thinnings. Two separate supply curves are estimated: one for roundwood and one for harvesting residues. The cost structure is based on an economic-engineering approach where the separate cost components are constructed from the lowest cost element into aggregates for labour, capital, materials and overhead costs for each forest resource. The results indicate an unutilized economic supply of 12 TWh of harvesting residues in Sweden. However, after these 12 TWh have been recovered it becomes more profitable to use roundwood for energy purposes than to continue extracting further amounts of harvesting residues.     

基于组态王的玉米果穗烘干监控系统设计

为充分保证种子烘干质量和发芽率，避免种子烘干效率低、人为操作失误等问题，采用研华ADAM4000系列数据采集模块，设计了基于组态王6.53的玉米果穗烘干监控系统，实现了对影响玉米果穗烘干质量的温度、压力数据的采集、处理和监控。在工控机上使用组态王实现了对数据分析处理、故障报警等功能，为提高果穗烘干质量提供了技术保障。应用情况表明，系统运行稳定可靠，人机界面友好，能够满足监控系统实时性、可靠性的要求。     

基于土壤液化原理的荸荠采收船的研究

荸荠的生长环境特殊，收获仍旧采用传统手工挖掘，劳动效率低，劳动强度大，难以挖净，而薯类收获机械又难以适应水田荸荠的收获，通过对荸荠生长地的土壤成分分析，基于土壤液化原理，搭建了小型实验平台，对荸荠挖掘机理进行了试验模拟。提出了一套适用于水田作物荸荠机械挖掘、筛分的流程，并对挖掘原理进行了实验探究。根据实验数据分析，获得了影响荸荠收获的主要因素。研究表明利用土壤液化原理可以使砂壤土液化，为该原理用于荸荠采收提供依据，为荸荠挖掘机样机的试制提供设计参考。     

铁路货车电能收集装置的机械结构设计

针对转K6型转向架,设计了一种适用于铁路货车的低成本、利用自身能量发电,满足铁路货车低功率用电需求的供电装置。此装置利用滚珠丝杠将悬挂系统的上下振动转变为发电机转子的旋转。通过分析弹簧中的空间以及货车运行过程中的振动情况,设计了滚珠丝杠、外壳等零件,并通过SolidWorks软件对装置进行了仿真。     

现代电子称重技术发展对森林收获计测的影响

回顾森林收获计测技术的发展历史,分析现代电子称量技术的发展应用前景,指出木材及木制品以体积计量计价的局限性和以重量计量计价的优势,认为当前一些木材市场上出现的买卖双方以重量而不是以材积计量计价现象有其历史必然性。基于以重量计量计价更为客观、准确、快捷、高效,并大幅降低成本的优势,其在纸浆等工业原料林经营、林业碳汇贸易等方面具有广泛应用潜力。     

浅析玉米缺粒与秃尖症状发生原因及对策

玉米生产过程中,而忽视了玉米缺粒与秃尖等生理病害的发生与预防,在生产实践中常造成严重的损失。为此探讨玉米缺粒与秃尖症状发生原因及防治对策,对减轻或避免玉米生产中玉米缺粒与秃尖等生理病害造成的损失有重要意义。     

泗阳县玉米测土配方施肥试验

为明确测土配方技术在泗阳地区玉米生产过程中的实际效果，通过田间试验对玉米生育期、产量构成和效益等进行了对比分析。试验结果显示：采用14.8-9-8的肥料配比能显著提升玉米肥料利用率，提高产量和收益。相较常规施肥，测土配方施肥对玉米生育期影响较小，但玉米穗粒数和千粒重提升效果显著，分别提升了1.88%和3.89%；测土配方施肥的氮、磷、钾肥利用率和养分平均利用率分别为40.77%、28.02%、51.18%，相较常规施肥分别提升了11.55%、4.07%、21.46%，养分平均利用率提升了12.36%；测土配方施肥籽粒产量为9535.04kg/ha，相较常规施肥增产429.99kg，增产率为4.72%，纯收益每公顷提升1269.60元。