水平摘锭式采棉机采摘头传动系统优化与试验

为了提高水平摘锭式采棉机的作业效率,针对国产采棉机在高速作业过程中存在采摘速比系数匹配不当、采摘头传动系统不合理的问题,该研究根据水平摘锭式采棉机采摘头结构与工作原理,对采摘头传动系统、采棉机采摘机理进行分析,根据传动系统传动要求和采棉机采摘条件,建立目标函数与约束条件,运用遗传算法和1stOpt软件对采摘头传动系统进行优化分析。优化结果为:滚筒动力齿轮齿数为72,离合器上齿轮变位系数为-0.14,滚筒动力齿轮变位系数为1.208,齿轮顶隙系数为1.25。结合采棉机作业要求搭建棉花采摘性能试验台,选取采摘滚筒转速113～143 r/min、作业速度5.93～7.20km/h,对优化前后采摘头的作业性能进行验证试验。结果表明:优化后的采摘头作业速度由6.4km/h提升至7.2 km/h,工作效率由4.86 hm~2/h提升至5.47 hm~2/h,提高了12.5%;优化后的采摘头在7.2 km/h的作业速度下,采净率由90.4%提升至93.7%,采净率提高了3.6%,含杂率由10.28%降至9.72%,含杂率降低了5.4%,验证了传动系统优化结果的合理性。该研究可为国产采棉机采摘头的研发提供参考。     

胶棒滚筒棉花采摘头采收性能试验

为缩短胶棒滚筒采棉机设计周期,提高胶棒滚筒采棉机作业质量,借助胶棒滚筒综合性能试验台,以滚筒转速、采摘行走速度和滚筒胶棒轴向间距为影响因子,以采净率、撞落棉损失率、含杂率为采摘性能指标,进行二次正交旋转组合试验,应用Design-Expert8.0.6软件,建立了影响因子与性能指标的回归模型,分析了各因子对性能指标的影响。采用多目标优化,确定最佳参数组合为：滚筒转速450 r/min,行走速度2.4 km/h,胶棒轴向间距44 mm。根据优化参数组合,重复验证试验结果为：采净率95.78%,撞落棉损失率0.89%,含杂率17.44%,与优化结果基本吻合。田间试验表明,4FS-3胶棒滚筒采棉机采净率为95.29%,撞落棉损失率为0.97%,含杂率为17.11%,主要性能指标达到国家采棉机作业性能指标要求。该研究为采摘头关键部件设计及工作参数改进提供参考,有效提高了采收效率和作业质量,对推动采棉机国产化和促进新疆棉花产业健康发展有一定意义。     

收获时期对稻麦轮作水稻机收损失构成的影响

为了研究稻麦轮作区水稻机械化收获损失构成特征及其不同收获时期的变化规律,该文在统一管理的同一水田,从全田90%的谷壳变黄开始至100%谷壳变黄止共12 d进行机收试验,测试水稻千粒质量、收割机夹带稻谷质量、割台碰撞掉粒数量、收获的稻谷质量等的变化情况。研究结果表明,水稻机收损失呈一元二次方程变化规律,越靠近11月11日的最佳收获日作业,损失率越低。计算得到稻麦轮作区水稻机收适时性损失系数为0.0009,相对损失率稳定在1%左右,绝对损失率在1.00%~6.80%之间变化。干物质损失是机收总损失的最主要来源,11月9日至13日平均总损失率为1.38%,平均干物质损失率为0.42%,占水稻机收总损失的30.43%;11月4日至18日,平均总损失率为3.61%,平均干物质损失率为2.61%,占水稻机收总损失的72.30%,最佳收获期应为11月9日至11月13日,即最佳收获日左右5 d。该研究可为稻麦轮作区水稻收获机械优化配置提供参考。     

Mathematical Modelling of Vacuum Pressure on a Precision Seeder

The purpose of this research was to determine the optimum vacuum pressure of a precision vacuum seeder and to develop mathematical models by using some physical properties of seeds such as one thousand kernel mass, projected area, sphericity and kernel density. Maize, cotton, soya bean, watermelon, melon, cucumber, sugarbeet and onion seeds were used in laboratory tests. One thousand kernel mass, projected area, sphericity and kernel density of seeds varied from 4·3 to 372·5 g, 5–77 mm², 38·4–85·8% and 440–1310 kg m⁻³, respectively. The optimum vacuum pressure was determined as 4·0 kPa for maize I and II; 3·0 kPa for cotton, soya bean and watermelon I; 2·5 kPa for watermelon II, melon and cucumber; 2·0 kPa for sugarbeet; and 1·5 kPa for onion seeds.The vacuum pressure was predicted by mathematical models. According to the results, the final model could satisfactorily describe the vacuum pressure of the precision vacuum seeder with a chi-square of 2·51×10⁻³, root mean square error of 2·74×10⁻² and modelling efficiency of 0·99.     

基于多纹理特征融合的麦田收割边界检测

自主导航是智能化农机完成收割作业的重要保障。该研究针对多云天气下光照易变化导致单一特征难以应对麦田环境的问题,提出基于多纹理特征融合的麦田收割边界检测方法。通过构建由图像熵特征和方向梯度特征组成的二维特征向量对麦田收割区域与未收割区域进行分类。其中,根据图像熵特征提取的特点,提出基于滑动窗口的直方图统计方法加速图像熵特征提取速度,较传统熵特征提取方法,本文方法耗时减少49.52%。在提取二维特征基础上,根据特征直方图分布特点,结合最大熵阈值分割算法对麦田图像进行初步分类,然后通过去除小连通区域对误分类区域进行剔除,进而运用Canny算子提取边缘轮廓点,得到分布于收割边界附近的待拟合点。最后,通过Ransac算法对拟合直线进行区域限制,得到较为准确的收割边界。试验结果表明,相比传统基于Adaboost集成学习算法提取收割边界,本文算法处理240像素×1 280像素的图像平均耗时为0.88 s,提速约73.89%;在不同光照条件下,收割边界平均检测率为89.45%,提高47.28个百分点,其中弱光照下检测率为90.41%,提高46.19个百分点,局部强光照下检测率为88.26%,提高46.00个百分点,强光照下检测率为89.68%,提高49.64个百分点。研究结果可为田间农机导航线识别提供参考。     

不同铃壳物理参数对机采棉采摘力学特性的影响

为了揭示铃壳物理参数对机采棉采摘力学特性的影响规律，该研究以新疆石河子地区具有代表性的3个机采棉品种（新陆早45号、新陆早66号、新陆早83号）为研究对象，通过室内棉花拉伸分离试验对比分析了3种机采棉在相同生长条件下，铃壳质量分数、心皮角以及锁角对棉花铃壳分离力的影响规律。试验结果表明：3种机采棉的棉花铃壳分离力范围分别为：0.155～0.980 N、0.275～0.967 N、0.258～0.667 N。在室内棉花拉伸分离试验中，3种机采棉棉花拉伸载荷-位移曲线相似，均表现为3个阶段：类弹性阶段、类屈服阶段、分离阶段，在类屈服阶段，棉花拉伸载荷-位移曲线出现锯齿状波动，当外部载荷达到一定程度时棉花内部的棉纤维组织发生局部错位。进一步研究表明，3种机采棉的铃壳质量分数、锁角、心皮角均对棉花铃壳分离力具有显著影响（P<0.01），呈负相关关系，且心皮角、铃壳质量分数与棉花铃壳分离力满足幂函数关系。研究结果表明，在机采棉作物育种时，应尽可能选育铃壳质量分数相对较小、锁角均匀的品种，在选择采收时机时，棉花成熟后应及早采收，避免收获前损失增大。该项研究成果对于指导机采棉育种以及新型棉花收获机械的设计和优化具有理论研究价值和现实意义。     

摘穗青贮型玉米复式割台的试验分析

该文通过正交试验，找出了对玉米复式割台收获质量有影响的多种因素；分析了各因素对摘穗机构和茎秆切割输送机构的影响；通过设计主要的工作部件，确定了复式割台主要的工作参数；对设计后的复式割台进行了性能检测，各项指标均达到了国家标准要求。结果表明，摘穗青贮型玉米复式割台对于各种玉米具有广泛的适应性。     

电磁处理提升采棉机摘锭力学性能和耐磨性

棉花机械化收获程度逐年提高,新疆生产建设兵团部分团场已实现100%机械化采收,整体达到85%以上。摘锭是采棉机的核心部件,其表面耐磨性能直接决定了采棉机的作业效率和机采棉品质,因此进一步提高摘锭表面耐磨性一直是重点关注的科学和技术问题。本文在不改变采棉机摘锭结构的基础上,基于电磁处理技术对市场化凯斯摘锭(Case)、迪尔摘锭(Deere)和国产摘锭(Yeer)进行电磁强化处理,并对3类摘锭电磁处理前后的力学性能进行实验室对比分析。摘锭电磁处理后试验结果表明:凯斯和国产摘锭残余应力下降60%,迪尔摘锭下降50%;凯斯、迪尔和国产摘锭涂层弹性模量与硬度的比值(E/H)都小于处理前的21,分别为18、17和20;电磁处理后凯斯和国产摘锭的磨痕宽度下降较迪尔显著,且随着载荷增大磨痕宽度下降趋势也随之增大,但仍是凯斯和国产摘锭下降较迪尔明显。相比较迪尔和国产摘锭,凯斯摘锭经电磁处理后力学性能提升效果最为显著,建议对凯斯摘锭电磁处理后进行田间耐磨性试验验证与评价。     

Development and Performance Evaluation of a Water Hyacinth Chopper cum Crusher

A water hyacinth (Eichhornia crassipes) chopper cum crusher was developed at College of Technology and Engineering, Udaipur, India to solve the problem of the bulk of freshly harvested water hyacinth during transportation. The performance of the chopper cum crusher was evaluated on the basis of its ability to reduce volume and weight of fresh water hyacinth. Two variables namely feed rate and knife speeds were studied. Relationships were developed between changes in specific volume, knife speed; percent weight loss and feed rates. Weight reduction studies showed that, with the increase in feed rate and knife speed, there was a decrease in weight loss. Maximum weight loss of 33·77% was achieved with the minimum feed rate of 1·0 t h⁻¹ and knife speed of 3·14 m s⁻¹. Regression models were developed to fit the data. The developed machine reduced the specific volume and weight of fresh water hyacinth by up to 64 and 31·54%, respectively, at the recommended feed rate of 1·0 t h⁻¹ and knife speed of 4·71 m s⁻¹.     

SE—Structures and Environment: Ammonia Emission and Nitrogen Balances in Mink Houses

Ammonia emissions from mink houses were measured over two seasons for growing kits in a two-row open-sided building with slurry gutters (385 mm wide). In the first season, a layer of sand was placed below the cages, and in the last season a layer of chopped barley straw on sand, to serve as a collector for urine and faeces dropped outside the gutter. When the slurry was removed weekly in the houses with slurry gutter and sand layer, the ammonia emission was 0·59 g [N] per animal per 24 h at 6°C and 1·15 g [N] per animal per 24 h at 16°C. By covering the ground area below the cages with a layer of chopped barley straw, renewed weekly, the nitrogen loss increased with the time since the latest renewal of the straw. One week after renewal of straw and removal of slurry, the emission amounted to 0·70 g [N] per animal per 24 h at 6°C and 1·44 g [N] per animal per 24 h at 16°C.Nine-week nitrogen balance measurements were carried out in three sections over the second season. When a layer of chopped barley straw on the ground area was renewed once a week, about 45% of the nitrogen in the consumed feed was collected in the slurry gutter by emptying the gutter twice a week. About 19% was collected in straw beneath the cages, about 5% was deposited in the carcass, about 20% evaporated, and the rest, about 11%, was assumed to be collected in the sand layer below the cages.     

SMS-1500型秸秆粉碎与残膜回收机的设计

为解决棉花收获后的残膜回收问题,设计了一种用于收获后棉秸秆切碎还田和残膜回收的联合作业机具,介绍整机的结构和工作原理,对主要工作部件做了设计,确定秸秆粉碎和残膜回收装置的结构参数,分析秸秆切碎和残膜回收过程,得出圆盘锯片切碎秸秆的条件。试验结果表明：在作业速度为5～5.5 km/h时,秸秆切碎长度小于20 cm,残膜回收率大于90%,作业后膜、杆分离,残膜自下而上揭起,残膜破损小。该机作业效率高,能耗小,回收的残膜集中堆放,可用于棉花收获后的残膜回收。     

Physical Properties of Vetch Seed

The physical properties of vetch seed were evaluated as a function of moisture content. The average length, width and thickness were 5·19, 4·33 and 3·63 mm, respectively, at 10·57% dry basis (d.b.) moisture content. In the moisture range from 10·57 to 20·63% d.b., studies on rewetted vetch seed showed that the thousand seed mass increased from 55·47 to 59·03 g, the projected area from 23·52 to 29·05 mm², the sphericity from 0·837 to 0·859, the true density from 1286·2 to 1369·9 kg m⁻³, the porosity from 33·08% to 39·68% and the terminal velocity from 9·94 to 10·33 m s⁻¹. The static coefficient of friction of vetch seed increased the linearly against surfaces of four structural materials, namely, rubber (0·350–0·387), aluminium (0·319–0·367), stainless steel (0·202–0·328) and galvanised iron (0·312–0·361) as the moisture content increased from 10·57 to 20·63% d.b. The bulk density and the shelling resistance decreased from 860·8 to 826·2 kg m⁻³ and from 148·73 to 62·68 N, respectively, with an increase in moisture content from 10·57 to 20·63% d.b.     

SMS-1500型秸秆粉碎与残膜回收机的设计

为解决棉花收获后的残膜回收问题,设计了一种用于收获后棉秸秆切碎还田和残膜回收的联合作业机具,介绍整机的结构和工作原理,对主要工作部件做了设计,确定秸秆粉碎和残膜回收装置的结构参数,分析秸秆切碎和残膜回收过程,得出圆盘锯片切碎秸秆的条件。试验结果表明：在作业速度为5～5.5 km/h时,秸秆切碎长度小于20 cm,残膜回收率大于90%,作业后膜、杆分离,残膜自下而上揭起,残膜破损小。该机作业效率高,能耗小,回收的残膜集中堆放,可用于棉花收获后的残膜回收。     

Simulated Farm Fieldwork, Energy Consumption and Related Greenhouse Gas Emissions in Canada

The amount of greenhouse gas (GHG) emissions that can be attributed to agricultural machinery management was analysed using computer simulation of farm power requirements, machine hours and fuel consumption. The ‘Farm Fieldwork and Fossil Fuel Energy and Emissions’ (F4E2) model optimised tractor and harvester power P. To minimise P for a single tractor for spring tillage and sowing, the model budgets available spring work time in half-day increments and adjusts implement widths to match. Other field operations in the model are powered by a tractor derived for spring. Emissions of GHG were estimated for ploughing, discing and sowing operations in springs, along with autumn harvesting, cultivation for weeds, spreading manure and sprying for pests. A grain trailer and a swather were considered as part of harvesting. Farm site estimates were extrapolated to regional and national scales with appropriate and available Canadian Census and farm survey data. Fuel consumption and GHG emission factors for petrol and diesel fuels were also analysed. Fuel efficiency and proper matching of equipment to tractors were important factors. Canada's 1996 Farm Energy Use Survey (FEUS) provided useful validation to the F4E2 energy consumption estimates. The model estimate of 71·6 PJ of diesel energy for 1996 was within 1% of the 72·0 PJ of diesel fuel energy that FEUS attributes to farm machinery for Canada. The 1990 Kyoto baseline estimate of GHG emissions was 6·5 Tg of CO₂ equivalent from both diesel and petrol for farm field operations in Canada.     

4MZ-2（3）型自走式采棉机主传动系技术方案分析与确定

根据采棉机主传动方式的要求，通过对发动机外特性、液压传动系统中变量泵和定量马达的调节性能特性的分析，针对国产自走式采棉机的主传动系的3种传动方案的优缺点进行分析比较，确定了国产自走式采棉机主传动系方案，该方案实现了在不同速度范围内的无级变速；并已用于自走式采棉机的生产中。     

Effect of Changing Temperature on the Deterioration of Soya Beans

Deterioration rates as indicated by carbon dioxide evolution for soya bean (Glycine max L. Merr.) stored under changing temperature conditions were quantified and compared with those predicted using equations. Experiments included soya bean moisture contents of 18, 22, and 26% (wet basis), constant storage temperatures of 15, 20, 25, and 30°C, and cyclical storage temperatures that changed between 15 and 25°C and between 20 and 30°C on a 24 h basis. Also, the growth of micro-organisms was identified after 10 days from the treatments by using the pour plate method.The results indicated an increase in deterioration by increasing storage temperature and moisture content of soya bean. Equations of carbon dioxide weight versus time for each moisture content and storage temperature were fitted. The longest allowable storage time to reach 0·5% dry matter loss (1132 h) occurred at lower moisture content and lower constant storage temperature, while the shortest allowable storage time (170 h) occurred at higher moisture content and higher constant storage temperature. The allowable storage times for soya bean stored under cyclical temperatures were close to the allowable storage time for soya bean stored at a constant temperature equal to the average cyclical temperature. Microbial infection levels increased with increasing storage temperature and moisture content. The increasing rate of micro-organism growth decreased by increasing the storage temperature over 25°C. However, this increasing rate of micro-organism growth for soya bean exposed to a cyclical storage temperature was usually lower than that for soya bean held at constant storage temperatures of about 20°C (the average of 15 and 25°C) and 25°C (the average of 20 and 30°C).     

刷辊式采棉机的改进设计与试验

为提高刷辊式采棉机作业质量,满足轧花厂对统收式采棉机采获籽棉的进厂要求,该文在已有4MZ-3B型刷辊式采棉机工作时存在问题基础上优化刷辊工作参数并增加与刷辊配套使用的回流结构提升了采净率,降低了落地损失率、挂枝棉率、漏采率;改进挑棉辊形式,避免该部件因缠绕造成棉桃分离气力输送管道入口堵塞的现象,降低整机故障率;将棉桃分离气力输棉管道由气吹式改进为气吸式,提高棉桃回收率;将气棉分离装置由网孔式改进为切线导流式,解决了棉桃分离气力输棉管道与机载预处理装置过渡问题,在排出气流的同时保证物料运动顺畅;将机载预处理装置由"一清一回收"式改进为"一清二回收"式,降低籽棉含杂率及清杂损失率。设计改进及优化后形成4MZ-3C型刷辊式采棉机,并进行对比试验。与4MZ-3B型刷辊式采棉机相比,采净率提高了3.42%、落地损失率降低了0.85%、挂枝棉率降低了0.89%、漏采率降低了1.05%、棉桃回收率提升了74.57%、清杂损失率降低了0.63%、籽棉含杂率降低了3.71%。将4MZ-3C型刷辊式采棉机各项指标均优于采棉机作业标准,在获取高采净率的同时,保证籽棉的低含杂率,可充分满足中国棉花生产机械化需求。     

Physical Properties of Raw and Parboiled Paddy

The physical properties namely, size and shape, bulk density, true density, and angle of repose at moisture contents ranging from 7·19 to 28·28% d.b. for raw paddy (IR-36) and from 12·24 to 43·53% d.b. for parboiled paddy were determined using standard techniques. In the case of raw paddy, the thousand grain weight increased from 23·04 to 27·16 g with an increase in moisture content from 10·45 to 32·13% d.b. Bulk density and angle of repose increased from 522 to 566 kg/m³ and 42·35 to 49·30°, respectively, with an increase in moisture content from 7·19 to 27·86% d.b. True density and porosity decreased from 1405 to 1348 kg/m³ and from 62·84 to 58·01% respectively, with an increase in moisture content from 7·19 to 27·86% (d.b.). In the case of parboiled paddy, bulk density and angle of repose increased from 507 to 564·8 kg/m³ and 39·90 to 43·89°, respectively, with an increase in moisture content from 12·24 to 43·53% d.b. True density and porosity decreased from 1411 to 1342 kg/m³ and from 64·08 to 57·91% respectively, with an increase in moisture content from 12·24 to 43·53%. The physical properties were linearly dependent upon moisture content.     

Research plot lengths for spindle harvested cotton

Abstract

Agricultural scientists who conduct field experimentation are confronted with variability in soil type, soil compaction, and nonuniform insect and disease distribution. One way to reduce variability is to use the appropriate size plots. Plots of cotton, Gossypium hirsutum L., having four rows spaced 1.02 m and harvested plot lengths of 3.04 to 32.22 m with four replications were established at Marianna, Calloway silt loam (fine‐silty mixed thermic Alfisols) and Clarkdale, Dubbs silt loam (fine‐silty mixed thermic Alfisols), Arkansas in 1978 and 1979 to determine the effects of row length and end borders on experimental variability. Results suggest that cotton research plots harvested with a spindle picker should not be less than 12.16 m in length. End border effects were additive but different for different plot lengths, locations, and growing season.     

SW—Soil and Water: Improvement of Whitish Oasis Soil, Part 1: Field Experiments with a Four-stage Subsoil Mixing Plough

A prototype four-stage subsoil mixing plough was designed in Japan and built in China for the improvement of whitish oasis soil. The machine was transported to two places in China for field tests where the whitish oasis soil is found. This paper presents the trash mixing rate into mixed layer of Bca and C horizons, the inverting rate of the Bca and C horizons and the draught of the plough in the whitish oasis soil.The results show that the rolling resistance of the tracked vehicle (T802), on which the plough was mounted, was about 8 kN and the draught of the first plough body which tilled the Ap horizon was about 4 kN with a working depth of 200 mm and a working width of 500 mm. The draught of the second plough body, which tilled the surface of the Ap horizon, was about 2 kN with a working depth of 50 mm. The draught of the third plough body increased steeply with greater working depths. The draughts were about 8, 14 and 24 kN, respectively, for working depths of 117, 239 and 300 mm. The draught of the fourth plough body also increased steeply with greater working depth. The draughts were about 7, 14 and 18 kN, respectively, for working depths of 117, 178 and 239 mm. When the whitish oasis soil was disturbed by the plough bodies, it was observed that the whitish oasis soil was very hard but comparatively brittle and easily broken up. This property explains the smaller draught requirements in the whitish oasis soil despite a greater soil strength. The values of the soil-inverting rate ranged between 0·45 and 0·6, and the average value was 0·5. Perfect inversion of the Bca and C horizons was not possible, but good mixing was achieved by the plough. The average trash mixing rate in Inner Mongolia was 0·85, and that in North of River was 0·95. These data show that even in Inner Mongolia where the trash material is long, a fairly uniform trash mixing was possible.