旋转式开沟机工作部件的运动分析

对旋转式开沟机的工作部件进行了运动分析，探讨了机具的工作原理，参数设计，开沟铲尖的运动轨迹，沟的几何参数及开沟铲的运动参数，为机具的设计提供了理论依据。     

一种新型链式开沟机设计参数和功率的确定

研究了一种适用于果园狭小作业空间的新型链式开沟机的结构和工作原理。通过功率消耗和作业效率等理论分析,提出了基本参数和功率消耗的确定方法,并根据果园园艺要求给出了１ＫＬＱ－８０型链式开沟机的具体设计结果,其配套动力为１１ｋＷ,最大开沟深度和宽度分别为８００ｍｍ、６５０ｍｍ,生产效率为１２５ｍ／ｈ。     

铲式玉米精密播种机振动特性模型建立与试验

为了研究铲式玉米精密播种机播种性能与农田不平度激励产生振动之间的关系,推导了稳态响应与理论粒距关系数学模型。由建立的数学模型得出铲式玉米精密播种机的播种性能主要由播种机的结构特征、播种机工作速度、倾斜圆盘勺式玉米精密排种器与耕作土壤表面间的距离、土壤不平度和土壤粘性决定。理论粒距与实际粒距的对比结果表明,两者分布趋势基本相同,建立的稳态响应与理论粒距关系数学模型可用于对工作状态下播种机的播种性能进行预测和分析。     

基于新型刀式矿土复合型开沟链的链式开沟机设计

介绍了一种新开发的开挖窄深沟的开沟链,并以这种链为基础设计了一种新式开沟机,通过对阻力和功率消耗的理论分析,对开沟机设计中各项参数的计算方法进行了研究,并对各项参数进行了确定。     

一种新型前置式开沟机刀盘的研究设计

上世纪80年代，国内研制出比较有代表性的大型圆盘开沟机、小型圆盘开沟机、链条开沟机、螺旋开沟机及抛土开沟犁等机型，并批量生产。其中，生产使用较多的为前置式小型圆盘开沟机。但是这些开沟机存在功耗大、抛土不匀，在泥泞田地无法使用的问题，为此提出一种小型开沟机刀盘的新设计方案，并进行理论分析。     

向日葵新品种LD5009特征特性及配套高产栽培技术

[目的]为宁夏地区优质向日葵新品种的选育及其生产利用提供技术支持。[方法]通过多年对向日葵新品种筛选及配套栽培技术的研究,宁夏农业科学院作物研究所成功筛选出了适合宁夏种植的食葵杂交种LD5009,并总结出了与之配套的向日葵沟种垄植机械化精量栽培技术。[结果]LD5009产量高,籽粒饱满,商品性好,抗病性强,但不抗黄萎病,种子价格高。沟种垄植机械化精量栽培技术能极大地节省农户的种植成本,提高种植户的经济效益,实现大面积机械化精量播种,对宁夏向日葵产业的发展有推动作用。[结论]LD5009的综合农艺性状较好,是一种高产优质的食葵杂交种。沟种垄植机械化精量栽培技术实现了大面积全程机械化种植,可以节约时间和成本。     

Drainage in Sweden -the past and new developments

Land drainage in Sweden has been regulated in various laws since the Middle Ages. The lowering of lake surfaces and the ditching of wetlands has been considered a valuable task to gain cultivable land, and more recently, to promote forest growth. However, in recent years the debate surrounding drainage in forests has been a matter of considerable discussion. The dry and hot summer of 2018 has awakened new views on the subject. Monitoring has shown an exceptionally low groundwater levels countrywide. Especially the islands of Öland and Gotland have faced groundwater shortages and the groundwater levels are still low in both small and large aquifers. Drainage within forest land has lacked any scientific basis until rather recently. Still, it has been a supported activity during the twentieth century. However, this has gradually as knowledge on the activity has increased and the ecology of downstream water bodies has been considered. Today, only the rinsing of existing drainage is actively practised, and it is surrounded by a number of recommendations which are still under discussion.     

橡胶园开沟机具的试制与试验

橡胶园田间管理过程中施肥、压青等农艺需要开沟或挖穴来辅助,该工作目前由人工或挖机完成,技术提升空间较大.该文阐述了一种简易开沟机具的工作原理和结构特点,该机具结构简单,易操作,可在橡胶园除草农艺前进行开沟作业.试验结果表明,开沟机具匹配55.161 8 kW(75马力)拖拉机,开沟深度这35 cm,生产率大于0.4 hm2/h,可有效提高生产效率和降低成本.     

Impacts of artificial drainage on amphibian breeding sites in hemiboreal forests

Artificial drainage is widely used to increase timber production and improve its quality in northern boreal and temperate forests, but its impact on biodiversity remains largely unexplored. Amphibians are particularly dependent on forest wetland qualities to complete their complex life cycles. We explored the supply of water bodies, their occupancy by amphibians, and persistence during the larval period comparatively in drained and natural forest plots in two years in Estonia. The water bodies in drained plots were more abundant but less diverse and of generally lower quality than in natural plots; however, the drainage ditches were favoured by newts. In the dry spring of 2009, water bodies were used more frequently in natural than in drained plots, while in the typical spring of 2010, several natural depressions appeared in drained plots and the frequency of use of water bodies did not differ between natural and drained plots. However, most natural depressions used for breeding in drained plots dried out before tadpole metamorphosis; such drying was not observed in natural plots. Thus, by profoundly changing natural hydrology, intensive large-scale forest drainage reduces the variety of water bodies and the quantity and quality of amphibian breeding sites. Moreover, we suspect that, at least in some years, temporary water bodies in drained areas function as ecological traps for amphibians. We suggest that, where possible, intact wet-forest areas with remaining natural hydrology should stay undrained. In areas already drained, breeding sites for amphibians can be provided by creating depression-like enlargements to some ditches.