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下落油菜籽粒在无秸秆正压纵向气流场中的漂移特性 被引量:11
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作者 宗望远 黄小毛 +2 位作者 潘海兵 查显涛 王廷廷 《农业工程学报》 EI CAS CSCD 北大核心 2015年第3期70-76,共7页
为降低油菜联合收获过程中的割台损失,针对机械直播和移栽的油菜,该文提出对行操作并使用正压气流田间在线收集处于下落过程中油菜籽粒的方法。利用自行试制的台架试验装置,首先设计正交试验,确定无秸秆正压气流场中影响收集效果的相关... 为降低油菜联合收获过程中的割台损失,针对机械直播和移栽的油菜,该文提出对行操作并使用正压气流田间在线收集处于下落过程中油菜籽粒的方法。利用自行试制的台架试验装置,首先设计正交试验,确定无秸秆正压气流场中影响收集效果的相关影响因素的显著性水平,然后对重要影响因素进行单因素试验,以获得对应的回归方程,为装置结构及工作参数的进一步优化提供预测依据。试验表明,影响收集效果的因素依次为收集单体高度、长度、风机工作电流频率及喷嘴仰角,且前3个因素对收集效果的影响较为显著,而喷嘴仰角对收集效果的影响不显著。4种因素对收集效果的影响趋势均符合二次多项式拟合,且收集效果(籽粒收集量)随收集单体高度、风机工作电流频率及喷嘴仰角的增加而增加,而随收集单体长度的增加而减小,其决定系数分别为0.9773、0.9985、0.9682和0.9686,因此在整机功率分配允许的情况下,应尽可能选用较大功率的风机,并不断优化管道布局、单体及喷嘴的结构形式及参数大小,以保证足够的气流场强度及作用范围,从而起到应有的收集效果。本文研究为后续进一步对有静止秸秆及有运动秸秆室内台架试验和田间试验条件下油菜割台籽粒损失气力式收集装置及试验的研究奠定了基础。 展开更多
关键词 收获 试验 优化 油菜 气流收集 割台损失
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油菜籽粒在割台纵向正压气流场中漂移运动的数值模拟 被引量:5
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作者 潘海兵 王廷廷 +2 位作者 黄小毛 查显涛 宗望远 《华中农业大学学报》 CAS CSCD 北大核心 2015年第3期117-123,共7页
为降低油菜联合收获过程中的割台损失,提出使用正压气流收集下落籽粒的方法,探讨处于下落过程中的油菜籽粒在正压气流场中的漂移特性,并采用Fluent和EDEM软件气固耦合模拟籽粒在无秸秆正压气流场中的漂移运动过程,利用自制室内台架试验... 为降低油菜联合收获过程中的割台损失,提出使用正压气流收集下落籽粒的方法,探讨处于下落过程中的油菜籽粒在正压气流场中的漂移特性,并采用Fluent和EDEM软件气固耦合模拟籽粒在无秸秆正压气流场中的漂移运动过程,利用自制室内台架试验装置进行台架试验验证模拟结果。结果表明:在流场中无油菜植株及籽粒初始下落高度一定的情况下,收集单体对从喷嘴正上方下落籽粒的收集率,随单体竖直高度的增加呈先增大后减小趋势,且随收集单体纵向长度的增加而减小;当其他条件不变时,在一定范围内,气流速度值越大,收集装置的收集效果越好;超出一定范围后,收集装置的收集效果又随气流速度值继续增大而减小。在收集单体竖直高度为435mm、纵向长度为620mm和籽粒初始下落高度为700mm等条件下,模拟得出的最佳入口气流速度约为20m/s,而台架试验得出的最佳出口气流速度约为30m/s,此时模拟和实测得到的收集率分别达到97.30%和92.10%。 展开更多
关键词 油菜 联合收获 割台损失 正压气流收集 气固耦合
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Solid phase microextraction(SPME) sampling under turbulent conditions and for the simultaneous collecting of tracer gases 被引量:1
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作者 Underwood Susanne W. Jong Edmund C. +3 位作者 Luxbacher Kray D. Sarver Emily A. Ripepi Nino S. Mc Nair Harold M. 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2015年第4期559-563,共5页
Solid phase microextraction (SPME) is a solvent-flee method of sample collection. SPME is an appealing method for sample collection because it is designed for the sampling of trace level analytes with short sampling... Solid phase microextraction (SPME) is a solvent-flee method of sample collection. SPME is an appealing method for sample collection because it is designed for the sampling of trace level analytes with short sampling times in a variety of environments. Additionally, SPME can be used to directly deliver a sample to a gas chromatograph (GC) for analysis by means of thermal desorption. In this paper, the performance of SPME under dynamic conditions was investigated. Additionally, the competence of SPME sampling for the simultaneous analysis of multiple trace analytes was also evaluated. This work is discussed in the context of underground mine ventilation surveys but is applicable to any industry in which ventilation circuits must be evaluated. The results of this paper showed that the performance of the 100 ~m PDMS SPME fiber was both precise and rapid under dynamic conditions. This SPME fiber was also able to simultaneously collect sulfur hexafluoride (SF6) and perfluoromethylcyclohexane (PMCH) with adequate sensitivity. 展开更多
关键词 Solid phase microextraction Sulfur hexafluoride Perfluoromethylcyclohexane Tracer gas Mine ventilation Air sampling
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Debris Flow in Metropolitan Area - 2011 Seoul Debris Flow 被引量:1
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作者 Chan-Young YUNE Yun-Ki CHAE +3 位作者 Joongcheol PAIK Gihong KIM Seung-Woo LEE Heung-Seok SEO 《Journal of Mountain Science》 SCIE CSCD 2013年第2期199-206,共8页
A large number of debris flows occurred simultaneously at around 8:30 to 8:50 a.m.on July 27,2011,at the center of Seoul,Korea.This area is located in the southern part of Seoul and is a densely populated district.As ... A large number of debris flows occurred simultaneously at around 8:30 to 8:50 a.m.on July 27,2011,at the center of Seoul,Korea.This area is located in the southern part of Seoul and is a densely populated district.As a result of the debris flow event,16 people were killed,30 houses were buried,and 116 houses were damaged around Umyeon Mountain,a relatively small mountain with a height of 312.6 m.Since the debris flow event,field investigations on the initiation and transportation zones of debris flows have been carried out.Rainfall data were collected from the automatic weather stations(AWSs) which are operated by the Korea Meteorological Administration(KMA).Video files recorded by residents were also acquired and used to analyze the flow characteristics of the debris flow.Field investigation shows that about 40 debris flows occurred around Umyeon Mountain and most of the debris flows were initiated by small slope failures.The effects of the precipitation that triggered the debris flows were analyzed as well.A landslide hazard map which considers slope gradient and aspect,strength of soil,hazard record,rainfall conditions,and vegetation,was constructed and compared with the initiation zones of debris flows. 展开更多
关键词 Debris flows Field investigation RAINFALL Flow characteristics Hazard map
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