物料状态对圆筒式短茎秆清理装置性能的影响

以喂入量和含杂率为试验因素，研究了圆筒式短茎秆清理装置的分离性能，分析了该装置沿长度方向的分离规律，给出了使用中的长度确定原则。     

联合收割机稻麦收获边界激光在线识别系统设计与试验

针对联合收割机收获边界在线识别问题,利用激光无损探测技术,开发了联合收割机收获边界在线识别系统。首先介绍了系统组成、激光传感器选型及工作原理,将传感器输出数据极坐标转换为直角坐标,建立稻麦轮廓特征数学模型。由于收获过程会产生大量的灰尘,会对激光探测距离及信号反射产生影响。通过与作物特征阈值比较,对受灰尘影响的错误数据进行有效识别与剔除。采用移动平均数字滤波算法,消除系统测量噪声。通过信号阶跃变化模式识别算法,实现了收获边界的在线检测,准确推算出联合收割机作业割幅,并进行了田间试验研究。试验结果表明,该系统可实现在线监测,收获边界测量误差不大于12 cm,可为联合收割机智能监控系统的实际应用提供参考。     

振动筛式花生收获机的设计与试验(简报)

介绍了4H-800型振动式花生收获机的总体结构、工作原理、技术特点以及关键部件结构与工作参数设计等。该设备主要由挖掘铲、单侧立式切割器、振动筛、驱振组件、行走轮、动力传动装置及机架等组成,与11～13.2 kW拖拉机配套使用,一次完成两行花生收获。试验和示范应用表明,该机具有作业顺畅、运行可靠、清土率高、损失率低等特点,纯生产率达0.1 hm2/h、总损率1.5%、破损率0.1%、含土率7.5%,各项指标优于行业和地方标准规定。     

便携式木材绞盘机新型卷筒离合器设计

在利用便携式木材绞盘机进行木材生产试验过程中,发现卷筒离合器在分离与接合过程中易出现卡阻现象,从而影响集材生产效率。在对牙嵌式离合器结构进行受力分析和卡阻原因分析的基础上,基于Solid Works的建模分析设计方法,设计了一种新型多孔旋转圆柱式卷筒离合器,该方法有效缩短了新型卷筒离合器的设计周期。新型卷筒离合器采用圆柱销与圆孔的嵌合,代替牙嵌式离合器牙嵌轴与牙嵌套的嵌合,同等试验条件下,旋转柱销式卷筒离合器平均分离时间分别比柱销式卷筒离合器节省3.71 s、比牙嵌式卷筒离合器节省8 s,改善了便携式木材绞盘机卡阻后离合器分离困难的现象,节约了离合器分离时间,从而有效提高了便携式木材绞盘机在集材作业中的生产效率。     

联合收割机割刀驱动行星轮系多目标优化设计

针对联合收割机割刀机构的工作特点,采用2K-H型行星齿轮机构,分析了割刀机构工作原理。通过建立2K-H型行星轮系的优化设计模型,应用NSGA-2算法对2K-H型行星齿轮机构进行多目标优化设计。以最小体积和最大承载力为优化设计目标,通过编制MATLAB程序得到Pareto前沿,进而得到最优解,与以往多目标优化设计比较,设计得到了很好的改善。     

Integrating traditional and local ecological knowledge into forest biodiversity conservation in the Pacific Northwest

The potential for traditional and local ecological knowledge to contribute to biodiversity conservation has been widely recognized, but the actual application of this knowledge to biodiversity conservation is not easy. This paper synthesizes literature about traditional and local ecological knowledge and forest management in the Pacific Northwest to evaluate what is needed to accomplish this goal. We address three topics: (1) views and values people have relating to biodiversity; (2) the resource use and management practices of local forest users, and their effects on biodiversity; (3) models for integrating traditional and local ecological knowledge into biodiversity conservation on public and private lands. We focus on the ecological knowledge of forest users belonging to three groups who inhabit the region: American Indians, family forest owners, and commercial nontimber forest product harvesters.     

Nontimber forest products and biodiversity management in the Pacific Northwest

Nontimber forest product harvesting in the Pacific Northwest is neither a new activity nor a disappearing relic of the pre-industrial era. Though the emphasis may have shifted from subsistence to commercial and recreational pursuits, harvesting and harvesters of wild species are still widespread throughout the region. Hundreds of businesses and thousands of harvesters earn part or all of their income from the harvests. Every year thousands of pounds and hundreds of nontimber forest products valued in the hundreds of millions of dollars are harvested from regional public and private forests. This harvesting of a large diversity of species represents a considerable subset of the overall terrestrial biodiversity in Pacific Northwest forests. Despite widespread extraction, little investment in research, planning, or basic inventorying and monitoring has been done on nontimber forest products. Without better information, land managers will be increasingly unable to make informed decisions on how to manage nontimber forest product biodiversity sustainably as demand for products increases.     

Quality assessment of rapeseed accessions by means of near-infrared spectroscopy on combine harvesters

Optimization of data collection processes in plant breeding programmes is of the highest importance for plant breeders. In rapeseed-breeding, data collection and selection must be carried out in a very restricted period of time because of the short time span between harvesting and sowing. Near-infrared spectroscopy on combine harvesters (NOCH) improves the data collection processes in breeding programmes of grain crops such as maize, and it may also improve the data collection processes in breeding programmes of rapeseed. The objective of this study was to assess the potential of NOCH for the determination of dry matter (DM), crude protein (CP), oil and glucosinolate (GSL) contents in rapeseed. A plot combine harvester equipped with a near-infrared diode-array spectrometer was used. Reference values for DM content were determined by the oven method. Reference values for the quality traits were established by laboratory near-infrared spectroscopy. NOCH showed a high potential for the determination of DM, CP, oil, and GSL contents. Use of NOCH in breeding may increase the efficiency of data collection processes and might dramatically accelerate the development of rapeseed cultivars.     

小型轴流滚筒结构及工作参数优化试验

解决动力偏低是小动力拖拉机配套联收机的关键问题,为寻求降低脱粒、分离部件功耗的途径,本研究设计了专用试验台架,用正交试验法,就脱粒滚筒的结构、工作参数优化等问题,进行了两年的室内试验。结果表明,当喂入量在0.75kg/s时,脱粒、清选全部功耗可控制在4.4kW以下。文中对根据试验结果研制的飞龙-0.75联收机的功耗、性能、田间实测情况也作了简要介绍。     

谷物质量流量测量装置的设计与试验

设计了一种新型冲量式谷物质量流量测量装置,该装置包括减震器、承载板、悬臂梁式弹性元件和机架等,并采用减震器来减弱收割机振动对测量精度的影响。试验证明:所设计的冲量式谷物质量流量测量装置测量误差平均值为4.29%,具有工程意义。