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自激振动深松机减阻试验研究 总被引：22，自引：6，他引：16
为了研究在土壤深松过程中深松机产生自激振动的原因及振动减阻机理,作者应用机械振动原理和信号测试技术,借助电测仪器与设备对由1SQ-127型全方位深松机所组成的自激振动式深松机系统进行了耕深、土壤阻力以及拖拉机牵引阻力等随机信号的测试及数据处理分析。系统地研究了“拖拉机－深松机－土壤”系统的动态特性,探讨深松机减阻节能的技术途径与方法。 相似文献
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改进的模糊化神经网络的土壤振动掘削阻力软测量模型 总被引：1，自引：1，他引：0
为实现土壤振动掘削过程节能减阻,分析了振动频率、振幅和插入速度等对土壤振动掘削阻力的影响,并以振动频率、振幅和插入速度等特征参数作为二次变量,采用清晰集构造模糊集方法对土壤振动掘削阻力软测量模型特征参数进行模糊化,利用改进的模糊化神经网络建立了土壤振动掘削阻力软测量模型。土壤振动切削力软测量实际应用结果表明,土壤振动掘削阻力软测量值的建模精度和泛化能力是很高的,所得的最大训练相对误差约为0.67%,最小测试相对误差约为-0.4%,有利于土壤振动掘削阻力的快速精确测量。 相似文献
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基于ALE有限元仿真的土壤切削振动减阻 总被引：8，自引：8，他引：0
针对浙江省茶园土壤压实问题造成小型茶园作业机功率不足问题,提出了茶园振动深松的土壤作业方法。以浙江龙井茶园压实土壤为分析对象,针对土壤深耕铲-土壤切削过程的动力学数值仿真,建立了土壤静态切削力学模型,并进行了土壤大变形切削的屈服失效分析。采用ALE算法模拟了土壤静态切削中深耕铲的切削阻力变化情况,建立了深耕铲-土壤的三维有限元模型并分析了振动切削的振动类型、频率、振幅以及深耕铲的前进速度对土壤切削阻力降低的关系,得出了振动频率和振幅对切削力的影响规律。进一步研究了不同的振动切削条件下,振动类型和刀具的切削速度对切削阻力的影响,通过合理选取一定的深松铲外加振动激励的振幅和频率能够得到最小的切削阻力,实例分析证明,振动频率取为25?Hz,振幅为14?mm时,振动切削的插入阻力能达到最小,切削阻力能降低约22%。上述研究结果为土壤振动切削减阻的外加振源参数优化提供了设计依据。 相似文献
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受迫振动深松机性能参数优化与试验 总被引：1，自引：7，他引：1
为解决目前深松作业机具耕作阻力大、深松深度不稳定、耕作质量不高的问题,该文采用振动减阻原理设计研制了受迫振动深松机。通过分析深松铲的结构和运动过程,建立深松铲的数学模型;确定影响深松牵引阻力的参数;采用正交试验方法得出影响受迫振动参数的最优组合:前进速度2 km/h,振动频率为10 Hz,振动角度为12°。为了验证性能参数最优组合的正确性,开展了受迫振动深松机性能参数检测试验。试验结果表明:振动深松前后,土壤各土层容重均下降,表层土下降达21.74%;在15~25 cm土层含水率增加16.02%;深松后地表平整,耕深稳定变异系数为7.37%,稳定性系数92.63%,振动深松作业后测得土壤扰动系数为57.11%,土壤蓬松度为36.96%,土壤蓬松度和扰动系数均达测试指标的要求。采用受迫振动能使振动深松机显著降低牵引阻力9.09%,减阻效果明显。该研究对深松机振动特性分析与性能参数设计提供了参考。 相似文献
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深松旋耕碎土联合整地机设计与试验 总被引：3，自引：2，他引：1
为减少耕作阻力、改善土壤耕层结构、提高碎土率,该文对联合整地机的深松部件、碎土机构进行设计,设计了入土角度可控的自激振动深松铲,并建立了自激振动深松铲的运动学模型和力学模型,确定弹簧行程为15mm、负载为7 500～15 000 N,并确定了弹簧的结构参数。设计了具有二次碎土功能的笼状碎土辊,并依据农艺要求确定了其结构参数。通过室内土槽试验,验证了自激振动深松铲的减阻效果和耕作质量,并对整机的作业质量进行了田间测试。土槽试验结果表明:与对照相比,自激振动深松铲平均减阻9.22%,土壤蓬松度和土壤扰动系数分别为26.16%和77.21%,减阻效果明显,作业效果较好。田间试验结果表明:联合整地机的深松深度稳定系数、旋耕深度稳定系数、地表平整度和植被覆盖率分别为94.92%、92.50%、1.17 cm和93.36%;笼状碎土辊在整个试验过程中未出现土壤粘附和拥堵现象,碎土率为84.18%,加装普通齿状碎土辊机具的碎土率为71.41%,笼状碎土辊的碎土率提高了12.77个百分点,碎土效果明显改善。深松旋耕碎土联合整地机减阻效果明显、整地质量好,可有效改善土壤的耕层结构,降低土壤容重,提高蓄水保墒能力。 相似文献
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基于振动减阻原理的深松机牵引阻力试验 总被引：11，自引：5，他引：6
为了减少深松时的牵引阻力,基于振动深松原理,研制出了1SZ-460型振动深松机。该文对振动深松减阻进行了试验分析研究,采用以振动作为单因素的试验设计,分别在不同作物残茬覆盖条件下进行试验。试验结果表明,振动深松和不振动深松的沟槽剖面宽度不同,振动后沟底形成了鼠道利于蓄水保墒,振动后土壤的体积质量减小,振动牵引阻力比不振动降低6.9%～17%,且不同的土壤特性和地表覆盖对牵引阻力会有一定的影响。试验结果为进一步优化机械结构、提高整机的动力和经济性能提供一定的参考依据。 相似文献
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该文在对振动轮—土壤系统动力学研究的基础上,建立了振动压路机整机动力学模型,应用新的国际标准,驾驶员在不同工况下的乘座舒适性能进行了理论评价。 相似文献
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仿生曲面在螺旋桩螺旋叶片上的应用研究 总被引：1，自引：2，他引：1
结合典型土壤动物表面减黏降阻特性，提出对防汛抢险螺旋桩螺旋叶片进行表面仿生处理。为了寻求仿生曲面在螺旋桩螺旋叶片上的降阻效果，该文首先以波纹型仿生曲面为研究对象进行台车牵引试验，包括正交试验以及与平板的对比试验；然后把试验结果应用于螺旋桩，进行了螺旋桩沉桩对比试验。波纹型仿生曲面台车牵引试验表明，在试验因素取值范围内，波纹型仿生曲面凸起宽度对减阻效果影响显著，而且随着波纹型仿生曲面凸起宽度的增大，减阻效果愈明显。螺旋桩沉桩对比试验表明在整个沉桩过程中仿生螺旋桩具有一定的减阻效果。 相似文献
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漫川漫岗黑土区水土流失综合治理范式 总被引：2，自引：0，他引：2
漫川漫岗黑土区是我国东北商品粮主产区和黑土坡耕地最集中的地方,也是坡耕地水土流失最严重的地区。根据漫川漫岗黑土区水土流失规律和特点,在已有水土流失治理模式的基础上,通过总结该区水土流失综合调控机制,凝练基于粮食安全的黑土区长坡缓坡水土流失综合治理范式,并对形成的水土流失综合治理范式体系的结构进行解析,对其推广应用效益进行分析,以补充和完善黑土区水土流失综合调控理论。结果表明:1)漫川漫岗黑土区水土流失治理应以坡耕地水土流失控制为主,水土流失综合治理调控主要由地表径流调控、沟道侵蚀调控和土地生产力调控3部分构成;2)基于粮食安全的黑土区长坡缓坡水土流失综合治理范式,以生态安全保障和粮食安全保障2大体系为支撑,系统结构主要包括水土流失立体防护体系结构和生态农业技术体系结构及二者之间的耦合;3)该范式可为促进东北漫川漫岗黑土区生态、社会和经济更协调发展提供科学参考和实践样板。 相似文献
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介绍了台湾学者为了公众使用方便,所建立的新土壤管理组系统。从土壤管理与改良土壤肥力的角度,选择适当的标准合并全省的土系,这些标准包括土壤深度、土壤质地、排水等级和土壤反应等4种辨别土系特征且在野外容易判断的重要土壤性质。通过研究,把全省924笔土系资料,最后归并为45个土壤管理组,并且认为可以根据当地的环境、气候特征、农作物种植面积多寡,做进一步的合并,以求土地利用的完整性与培肥管理上的方便。 相似文献
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Roy W. Simonson 《Geoderma》1975,14(1):1-22
The paper describes a model of the soil system. There are two different, partly complementary means of building such a model. One approach is to construct, using empirical physical science methods, an isomorphic model, in which each and every component (variable) of the system is an element in the model. The other approach is to build, using a systems synthesis methodology, a homomorphic model, in which several components of the system are grouped to form a single element in the model. The latter method is adopted in this paper because of its suitability for modelling at the level of the whole soil system.As regards forming the basis of a homorphic model of the whole soil system, existing concepts of soil genesis have limitations: either they are very complex isomorphic models, the implementation of which presents virtually insurmountable problems; or they are homomorphs but too general to be used in their present form. And the concepts make no reference to the functional boundaries of soil system units. Indeed, such a unit has not yet been satisfactorily defined; the nearest to it is the soil catena, which is considered at length in the paper. Some of these problems are resolved by the concept of soil landscape systems which, synoptically, is as follows. A basic functional of the soil system, it is proposed, is a three-dimensional body of soil known as a soil landscape system or a “valley basin”, that (1) is bounded by the soil surface, valley watershed and weathering front at the base of the soil; (2) forms part of a more extensive valley basin network; and (3) functions as an open system. The flux of solids, colloids and solutes within and across the landscape is shown to be organized within the framework of these soil system units, and is discussed in terms of inputs, outputs and storages of the soil skeleton (clastic sediment) subsystem, the soil plasma subsystem and the soil solution subsystem.The value if the soil landscape system concept as a homomorphic model is stated. Five main advantages are outlined which relate to the five main features of the model: it has clearly and comprehensively defined basic system elements; it has functionally defined, three-dimensional system boundaries; the relationships between elements can be established from empirical hypotheses; there is transport and conservation of matter and energy as in the very successful models of hydrological systems and ecosystems; change of the system through time can be directly studied by computer simulation and not indirectly by statistical extrapolation from empirically derived behaviour patterns. The model, it is hoped, should provide a rational physical basis for simulating soil systems. 相似文献
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中国农田生产系统土壤保持功能及其经济价值 总被引：26，自引：0，他引：26
农田生产系统不仅为人类提供了多种多样的农产品,同时,农作物对地表的覆盖以及各种水土保持措施的采用,使农田生产系统也发挥着重要的土壤保持功能。根据计算,我国农田生产系统每年保持土壤的数量为101.9×108t,其中,西南地区、黄土高原区和东北地区的农田土壤保持功能最为突出。采用市场价格法、机会成本法和影子工程法对农田保持土壤的价值进行评估,结果表明:我国农田每年保持土壤养分的价值为4408.50×108元/a,减少耕地废弃价值为164.09×108元/a,减轻淤积的价值为53.74×108元/a,总计4626.66×108元/a,相当于2000~2002年我国种植业平均产值的32.08%。其中,东北地区、黄土高原区和西南地区保持土壤价值较大,合计为2851.8×108元,占总价值的61.6%。 相似文献
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基于RS和GIS的四川省李子溪流域土壤侵蚀动态变化 总被引：25，自引：8，他引：25
以遥感影像为主要信息源 ,利用地理信息系统软件 ARC/INFO强大的空间分析功能 ,对四川省李子溪流域 1986年和 1999年土壤侵蚀动态变化进行监测 ,估测侵蚀量 ,并对李子溪流域土壤侵蚀动态变化进行了分析 ,探讨了土壤侵蚀动态变化与土地利用变化的关系 ,侵蚀强度动态变化与侵蚀量变化的关系 ,为李子溪流域今后的水土保持工作提供了科学依据和决策支持。 相似文献
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The environmental application and risk assessment of manufactured nanoparticles (MNPs) in soil greatly depend on our understanding of the interactions between MNPs and soil components. Because of the complexity of the soil system and the very early stage of MNP research in soil, our understanding of MNP behaviour in this system is very limited. This review summarizes the progress of research on MNPs and their implications for soils. Manufactured nanoparticles are applied deliberately for soil remediation and are also released unintentionally through various other pathways to soil. Their colloidal behaviour in the soil system is discussed by analysing the effect of dissolved organic matter, light irradiation, water chemistry conditions and biological processes. The methods currently used for modelling MNP leaching and transport are summarized and several requirements for model improvement are proposed. The current topics regarding the environmental risks of MNPs (such as identifying the toxicity of MNPs and their dissolved ions, evidence that MNPs may be taken up by soil organisms or the risks of other pollutants as affected by the presence of MNPs) are described. Future research directions are discussed and proposed. 相似文献
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J. W. MUIR 《European Journal of Soil Science》1969,20(1):153-166
Definitions of natural classification are given which emphasize the importance of theory and concept in the construction of natural systems. The proposed system is based on two principles of soil formation. The first principle emphasizes the three-dimensional nature of soil bodies. The second principle, known as the Principle of Developmental Sequences, is concerned with stages of soil development. The many developmental sequences identified by pedologists are correlated by means of a small number of constituents which are lost and gained during soil formation. These constituents, in an order of eluviation/illuviation, are used to rank the properties on which the proposed system is based. Soil horizons are defined according to the ranked properties and the classes of the system are, in turn, defined in terms of the horizons, with the result that the central statement of the system is the Principle of Developmental Sequences. 相似文献
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马瑞峻 Michael Short Craig Lobsey Alex McBratney Brett Whelan Budiman Minasny 孙光永 《农业工程学报》2010,26(4):156-161
土壤在作物的生长过程中起到了重要的作用,所以对于基于决策的作物生产管理,土壤信息是必需的。传统的土壤取样获取土壤信息技术耗时且成本高,尤其是对于大规模农田土壤信息测量。目前一些近地面的可连续测量的土壤信息传感器技术能够提供高精度的数字土壤信息地图,然而这些商业化的技术成熟的传感器通常需要单独使用。该文提出了将γ射线光谱仪GR320、利用电磁感应原理的EM38和EM31以及Veris 3100和Veris pH这些可在农田近地面连续测量的土壤特性测试传感仪器集成在一起同时使用的方案,介绍了此集成系统的硬件设备和相关特性参数以及今后需要继续研究解决的问题。利用该系统可一次获得不同的土壤特性参数数据,如土壤矿物质含量,不同深度的土壤电导率值和土壤pH值等,可避免多次测量车辆行走对土壤的压实。多传感器数据之间的互相补充可以进一步提高且更有利于精确农业中基于土壤信息的决策规划。该系统适用于大面积农田土壤特性测量。 相似文献
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SOIL CLASSIFICATION IN THE SOIL SURVEY OF ENGLAND AND WALES 总被引：2，自引：0，他引：2
B. W. AVERY 《European Journal of Soil Science》1973,24(3):324-338
The development of soil classification as a basis for soil mapping in England and Wales is briefly reviewed, and a system for future use is described. The things classified are soil profiles, and classes are defined by relatively permanent characteristics that can be observed or measured in the field, or inferred within limits from field examination by comparison with analysed samples. Profile classes are defined at four categorical levels by progressive division, and are termed major groups, groups, subgroups, and soil series respectively. Classes in the three higher categories are defined partly by the composition of the soil material and partly by the presence or absence of particular diagnostic horizons, or evidence of recent alluvial origin, within specified depths. Soil series are distinguished by other characteristics, chiefly lithologic, not differentiating in higher categories. Most of the soil groups, regarded as the principal category above the soil series, are closely paralleled in other European systems, in the U.S.D.A. system (7th Approximation with subsequent amendments), or in both. Compared with the system used hitherto, the main innovations are the use of specific soil properties to define classes at all categorical levels, and the separation at group level of classes based primarily on inherited lithologic characteristics. The soil-profile classification provides a uniform basis for identifying soil map units, considered as classes of delineated soil bodies. When a map unit is identified by the name of a profile class, it is implied that most of the soil in each delineation conforms to that class, and that unconforming inclusions belong to one or more closely related classes or occupy an insignificant proportionate area. Map units identified by land attributes not differentiating in the profile classification are termed phases. 相似文献