检索结果-南通市图书馆

The Effect of Mechanical Conditioning on Physical Conditions of Miscanthus Plants

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

American Journal of Plant Sciences 2023年第1期14卷 77-88页

作者： Sebastian Redcay jude liu Department of Agricultural and Biological Engineering The Pennsylvania State University Pennsylvania United States

Miscanthus is an emerging dedicated energy crop, which can provide excellent yield on marginal lands. However, this crop is more difficult to harvest than many conventional energy crops such as corn stover and switchgrass due to its tall and rigid stalks. Crop samples for laboratory studies were collected from the field and the effects of roll spacing, roll speed, and crop input of a mechanical conditioning device on the physical conditions of miscanthus were studied in a lab setting. Test results showed that mechanical conditioning is effective to change the physical conditions of miscanthus to make baling possible or easier. Results also showed that the roll spacing had the most significant impact on the physical conditions of miscanthus, shown by a 115% increase in conditioning over a 0.95 cm (75%) reduction in roll spacing. Increased roll spacing and speed were shown to decrease the amount of torque required to condition the miscanthus.

关键词： Energy Crop Baling Strength Preprocessing

Effect of Harvesting Time and Moisture Content on Energy Consumption of Compressing Switchgrass

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

American Journal of Plant Sciences 2014年第21期5卷 3241-3249页

作者： Benjamin Kemmerer jude liu Department of Agricultural and Biological Engineering The Pennsylvania State University University Park USA

As a dedicated energy crop, switchgrass may be harvested in fall or early spring depending on weather conditions, field capacities of harvesting machines, storage capacities, field management and availability of machine operators. To reduce storage space demand and increase transportation efficiency, harvested switchgrass should be densified. This research was conducted to examine energy consumption of compressing switchgrass collected from various harvesting seasons. Results indicated that the switchgrass harvested in the spring required the maximum energy consumption to process due to its dry and brittle nature. Conversely, the switchgrass harvested in the fall required less energy to compress due to its higher moisture content and associated reduction in resistive forces. For the same moisture content, fall harvested switchgrass would consume less energy to compress compared to spring harvested due to changes in properties of switchgrass over the winter.

关键词： Biomass Mechanical Properties Densification Energy Consumption

Large square baling and bale handling efficiency—A case study

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Agricultural Sciences 2012年第2期3卷 178-183页

作者： Benjamin Kemmerer jude liu Department of Agricultural and Biological Engineering The Pennsylvania State University University Park USA

Large square baling is currently recognized as a high efficiency biomass harvesting system. Baling, bale collecting, and storing at a commercial wheat straw farm was studied as a typical large square bale harvesting system. Factors that affect large square bale production and handling logistics were quantified. Field operations of a large square baler, two bale handlers, and three bale trucks were observed in a full day field operation. System performance was analyzed and material capacities of all machines used in this system were determined based on field measurements. System limitations were quantified, and means to increase system efficiency or reduce production costs were discussed. Results showed that 340 wheat straw bales at a density of 116 kg·m-3 (wet matter) were made with a single large square baler during 8 h field operations. The number of bales produced was the system limitation when one baler, two bale handlers and three bale trucks were used. Adding a baler or reduce the number of operators can increase system efficiency. The large square baler used in this study had a material capacity of 13 Mg·h-1. Similar baling trials were conducted in a switchgrass field and results indicated that the baler had the same material capacity.

关键词： Biomass Logistics Material Capacity Harvest

Modeling of Soil Movement by Tillage

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Modeling of Soil Movement by Tillage

Field test and cost analysis of four harvesting options for herbaceous biomass handling

国际农业工程大会

作者： jude liu David A. Lobb Ph.D Department of Biosystems Engineering University of Manitoba Winnipeg Manitoba Canada R3T 2N2 Ph.D. Associate Professor Department of Soil Science University of Manitoba Winnipeg Manitoba Canada R3T 2N2.

＜正＞ The process of tillage tool-soil-crop residue interaction was described based on the video recorded in a soil bin and a field experiment using a 325-mm-wide sweep. Then, a three-dimensional model was developed to predict the soil displacement by the sweep. Soil displacement by tillage tool was simplified into three components: forced, projectile, and rolling displacement. The model was verified

关键词： Tillage Soil Movement Model

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

International Journal of Agricultural and Biological Engineering 2011年第3期4卷 58-68页

作者： Douglas Brownell jude liu Department of Agricultural and Biological Engineering The Pennsylvania State UniversityUniversity ParkPA16802USA

The nature of most biomass materials is a low bulk density as compared to traditional fuel *** handling cost could be a limiting factor in utilizing biomass *** available harvesting machinery systems and associated costs is critical to future *** popular harvesting machinery systems were studied and costs were analyzed based on field measurements and *** four systems included(1)round baling and round bale handling systems,(2)large square baling and square bale handling systems,(3)forage harvester and trucking systems,and(4)large square baling plus square bale compression *** indicated that a self-loading forage wagon can reduce the cost to harvest a crop but requires more harvest *** square bales were found to reduce cost of handling and transport as compared to round *** research is needed to determine storage costs and deterioration loss of the two bale *** square bales were found to reduce storage,handling and transport *** bale machinery has a high initial cost,which currently makes only valuable for hay export.

关键词： harvesting machinery system herbaceous biomass field cost

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

黑白虹——张仃装饰绘画本源探寻

装饰 2005年第4期 17-19页

作者：刘巨德清华大学美术学院

新世纪初回首五十年前的中国美术,确有遥远的感觉.然而时光之久远,却能令心灵更加明净,思想更加清澄.理解和研究89岁高龄的美术界老前辈张仃先生40岁时的艺术思想和创作,体验他当时作品中的情感和一个真正艺术家的人生,唯愿真正了解的,... 详细信息

新世纪初回首五十年前的中国美术,确有遥远的感觉.然而时光之久远,却能令心灵更加明净,思想更加清澄.理解和研究89岁高龄的美术界老前辈张仃先生40岁时的艺术思想和创作,体验他当时作品中的情感和一个真正艺术家的人生,唯愿真正了解的,是怎样的生命,怎样的情怀,怎样的文化积淀,能够使张仃先生在特殊的时代,创造了中国美术史上奇丽的一页.

关键词：本源绘画装饰文化积淀艺术家美术中国

在线全文

学校读者我要写书评

暂无评论

彩色雨——吴冠中绘画境界初探

装饰 2005年第10期 8-9页

作者：刘巨德清华大学美术学院

一吴冠中先生,字荼.荼,白也;草也;苦味也;痛也.释其为一种苦菜,一种茅草的花,生于田野山泽中,浩瀚无际,洁白茂盛,得霜后甜脆而美.与火并称'如火如荼',寓先生追求艺术激烈、强烈、热烈也.

关键词：吴冠中绘画彩色艺术

在线全文

学校读者我要写书评

暂无评论

大方捆压捆及搬运作业效率的实证研究

中国农机化学报 2017年第3期38卷 137-141页

作者： Benjamin Kemmerer jude liu 董洁芳美国宾夕法尼亚州立大学

大方捆压捆是当前一种公认的高效生物质收获系统。通过对一家商业化农场的麦秸压捆、运捆及贮存的全过程进行了研究,建立一个典型的大方捆收获系统(包括1台大方捆压捆机、2台方捆搬运机和3辆方捆运输车),并对影响大方捆生产及搬运流程... 详细信息

大方捆压捆是当前一种公认的高效生物质收获系统。通过对一家商业化农场的麦秸压捆、运捆及贮存的全过程进行了研究,建立一个典型的大方捆收获系统(包括1台大方捆压捆机、2台方捆搬运机和3辆方捆运输车),并对影响大方捆生产及搬运流程的各种因素进行量化分析。根据一个工作日的连续观测结果,分析该收获系统的田间作业性能,确定该收获系统中所使用每一台机械的物料作业能力。本研究还对该收获系统的制约因素进行量化分析,进而探讨提高生产效率或降低生产成本的途径。结果显示,经过8h田间操作,1台大方捆压捆机可以完成340个密度为116kg/m3(湿重)的麦秸捆,为该收获系统的最大生产能力。增加1台压捆机或减少其它机械操作员的数量,可以提高该收获系统的作业效率。本研究中所使用的大方捆压捆机的物料作业能力为13t/h。在种植柳枝稷的田地中进行类似的压捆试验,结果显示该压捆机的物料作业能力相同。

关键词：生物质物流物料作业能力收获

在线全文

学校读者我要写书评

暂无评论

自卸汽车后推式举升机构运动学分析

青岛建筑工程学院学报 2000年第1期21卷 71-74页

作者：胡彩旗张泰刘聚德青岛建筑工程学院机械工程系青岛266033

根据油缸后推连杆放大式举升机构在举升过程中各构件的运动特点 ,运用复数向量和方程降维相结合的方法建立了举升机构运动学分析数学模型 ,为自卸汽车后推式举升机构运动学分析 ,性能评价及合理设计提供了理论基础 .

关键词：举升机构运动学分析自卸汽车后推式