排序方式: 共有84条查询结果,搜索用时 15 毫秒
1.
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。 相似文献
2.
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. 相似文献
3.
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. 相似文献
4.
5.
6.
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. 相似文献
7.
切纵流联合收获机小麦夹带损失检测试验与分析 总被引:3,自引:3,他引:0
为及时获知切纵流联合收获机在田间收获时的夹带损失情况,该文将切纵流联合收获机上的刀形齿切流滚筒、辅助喂入轮和钉齿纵轴流滚筒在实验室内建成切纵流脱粒分离试验台,在7 kg/s小麦喂入量时进行脱粒分离性能试验,测定脱出混合物中各成分的含量和纵向分布规律,建立脱出混合物脱分系数矩阵,求解出切纵流联合收获机上脱粒分离装置的脱分矩阵方程。利用阵列式聚偏氟乙烯PVDF压电薄膜传感器测量切纵流联合收获机田间收获时钉齿纵轴流滚筒下第11接料盒位置分离出的籽粒量,运用脱分矩阵方程计算出夹带损失质量并与人工实测值进行比较。结果表明,田间收获时运用PVDF压电薄膜传感器预测的夹带损失质量与人工实测值的误差为-4.82%~-5.87%。该研究可以对田间收获的籽粒夹带损失进行实时监控。 相似文献
8.
4FZ-30型自走式番茄收获机的研制 总被引:3,自引:3,他引:0
为了适应加工番茄的大面积采收,该文设计了一种适用于加工番茄的自走式收获机,并阐述了该机的总体结构及切割捡拾装置、分离装置和色选装置三大核心工作部件的工作原理,并进行了田间试验。试验结果表明,在地形平坦,土壤绝对含水率为18%,番茄成熟度为98%的情况下,该机平均生产率为0.26%hm2/h,平均损失率为4.36%,平均破损率为4.10%,平均含杂率为3.09%,各项指标均达到行业标准NY/T1824-2009,满足设计要求。该研究为推动番茄收获机的国产化进程奠定了基础。 相似文献
9.
收割机作业速度多目标控制模型的鲁棒优化设计 总被引:1,自引:1,他引:0
本文围绕稻麦联合收割机作业速度控制策略问题,以收割机作业质量、作业效率、能效利用率为控制目标,基于模型鲁棒优化理论,建立了基于多目标控制的收割机作业速度控制模型;在分析各控制目标约束条件和满足收获损失率、作业效率和能效系数期望区间的基础上,考虑控制目标对田间作业参数变化的灵敏度,提出一种基于模拟退火算法的控制目标权重因子优化方法。田间试验结果表明,当草谷比变化率为40%,谷物密度变化率为29.9%时,本控制模型可将收获损失率控制在0.42%~0.43%范围内,脱粒滚筒功耗15.12~16.99kW,并能实现收割机复杂工作环境下作业速度的合理控制,进一步验证了控制模型的鲁棒性和可行性。 相似文献
10.
基于小区育种的收获机智能测产系统 总被引:2,自引:1,他引:1
摘要:目前,中国境内大部分育种单位产量测试主要采用人工抽检方式完成,劳动强度大,工作效率低,测试数据的质量与发达国家所采用的测产系统相距甚远。为解决这一问题,该文设计研制了一种基于小区育种的收获机测产系统。该测产系统包括上位机和下位机两部分。下位机采用美国TI公司的MSP430单片机,通过粮食水分传感器,重量传感器,环境温湿度传感器,GPS模块,获取收获机的产量、粮食水分含量、环境温湿度及GPS地理位置等信息。上位机采用能够运行MCGS组态软件的嵌入式触摸屏作为人机交互界面。下上位机通过RS-232串口及Modbus协议实现通讯,完成数据的传输。该系统可以自动实现地块号与产量相关数据的准确对应关系,并利用U盘实现海量数据的导入、导出等数据管理功能。并利用虚拟试验验证了该收获机测产系统方案正确和可行,并且可明显提高育种测产的工作效率和数据的准确性。 相似文献