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Design Principles of the Non-smooth Surface of Bionic Plow Moldboard 被引量:28
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作者 Luquan Ren, Shiqiao Deng, Jingchun Wang, Zhiwu Han Key Laboratory of Terrain-Machine Bionics Engineering (Ministry of Education,China), Jilin University at Nanling Campus, Changchun 130022,P.R. China 《Journal of Bionic Engineering》 SCIE EI CSCD 2004年第1期9-19,共11页
The diverse non-smooth body surfaces to reduce soil adhesion are the evolutional results for the soil animals to fit the adhesive and wet environment and can be used as a biological basis for the design of bionic plow... The diverse non-smooth body surfaces to reduce soil adhesion are the evolutional results for the soil animals to fit the adhesive and wet environment and can be used as a biological basis for the design of bionic plow moldboard. The model surfaces for bionic simulation should be taken from soil animal digging organs, on which the soil motion is similar to what is on the surface of moldboard. By analyzing the distribution of non-smooth units on the body surface of the ground beetle jaw and the soil moving stresses, the design principles of the bionic moldboard for the local and the whole moldboard were presented respectively. As well, the effect of soil moving speed on reducing adhesion, the dimensions relationship between soil particles and non-smooth convexes, the relationship between the enveloping surface of non-smooth convexes and the initial smooth surface of the plow body, and the convex types of the sphere coronal and the pangolin scales,etc.were discussed. 展开更多
关键词 BIONICS plow moldboard non-smooth surface design principle
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Evaluation of plow system performance in long-wall mining method using particle flow code 被引量:1
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作者 Mohammadreza Ajamzadeh Vahab Sarfarazi Hesam Dehghani 《International Journal of Coal Science & Technology》 EI 2019年第4期518-535,共18页
The underground or open-pit methods are used for the extraction of mineral resources,each of which is divided into different categories.Coal is one of the mineral resources,which is exploited either by the surface or ... The underground or open-pit methods are used for the extraction of mineral resources,each of which is divided into different categories.Coal is one of the mineral resources,which is exploited either by the surface or the underground methods.The long-wall mining is one of the methods for the underground coal mining.In this method,which is a mechanized one,some machines such as the shearer or plow are used for the mining.The coal mine in Parvadeh,Tabas is a mechanized mine that is extracted by the long-wall mining.The modeling with particle flow code software was used in this mine for the evaluation of plow performance using the coal specifications.In this regard,the sample was first calibrated by sampling from the Parvadeh coal mine and performing the uniaxial and Brazilian tests on the model.Then,the modeling was done by constructing the model and using the variables such as the clearance angle and the linear velocity of the plow.After making 28 models for the plow,the best model of the plow was selected based on the maximum force applied to the machine in the X direction.Finally,the results of this study showed that the best plow performance is for a model with the clearance angle of zero and the linear velocity of 9 mm/min,and the maximum force applied to this model is equal to 39,000 kN in the X direction. 展开更多
关键词 plow LONG-WALL MINING PARTICLE FLOW CODE NUMERICAL modeling
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Optimized Design for the Plow of a Submarine Plowing Trencher 被引量:1
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作者 Hanyang Gong Ruhua Yuan +3 位作者 Xiaodong Xing Liquan Wang Zhipeng Wang Haixia Gong 《Journal of Marine Science and Application》 2013年第1期98-105,共8页
The plow of the submarine plowing trencher is one of the main functional mechanisms, and its optimization is very important. The design parameters play a very significant role in determining the requirements of the to... The plow of the submarine plowing trencher is one of the main functional mechanisms, and its optimization is very important. The design parameters play a very significant role in determining the requirements of the towing force of a vessel. A multi-objective genetic algorithm based on analytical models of the plow surface has been examined and applied in efforts to obtain optimal design of the plow. For a specific soil condition, the draft force and moldboard surface area which are the key parameters in the working process of the plow are optimized by finding the corresponding optimal values of the plow blade penetration angle and two surface angles of the main cutting blade of the plow. Parameters such as the moldboard side angle of deviation, moldboard lift angle, angular variation of the tangent line, and the spanning length are also analyzed with respect to the force of the moldboard surface along soil flow direction. Results show that the optimized plow has an improved plow performance. The draft forces of the main cutting blade and the moldboard are 10.6% and 7%, respectively, less than the original design. The standard deviation of Gaussian curvature of moldboard is lowered by 64.5%, which implies that the smoothness of the optimized moldboard surface is much greater than the original. 展开更多
关键词 submarine plowing trencher moldboard surface plow surface optimized design multi-objective genetic algorithm surface smoothness
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Soil remediation of degraded coastal saline wetlands by irrigation with paper mill effluent and plowing
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作者 XIAMeng-jing LIU Zhi-mei LU Zhao-hua 《Journal of Forestry Research》 SCIE CAS CSCD 2012年第2期267-274,共8页
Combined with anti-waterlogging ditches, irrigation with treated paper mill effluent (TPME) and plowing were applied in this study to investigate the effects of remediation of degraded coastal sa- line-alkaline wetl... Combined with anti-waterlogging ditches, irrigation with treated paper mill effluent (TPME) and plowing were applied in this study to investigate the effects of remediation of degraded coastal sa- line-alkaline wetlands. Three treatments were employed, viz., control (CK), irrigated with 10 cm depth of TPME (I), and plowing to 20 cm deep before irrigating 10 cm depth ofTPME (IP). Results show that both I-treatment and IP-treatment could improve soil structure by decreasing bulk density by 5% and 8%. Irrigation with TPME containing low salinity stimulated salts leaching instead of accumulating. With anti-waterlogging ditches, salts were drained out of soil. Irrigation with 10 cm depth of TPME lowered total soluble salts in soil and sodium adsorption ration by 33% and 8%, respective!y, but there was no significant difference compared with CK, indicating that this irrigation rate was not heavy enough to remarkably reduce so!l salinity and sodicity, Thus, in-i: gation rate should be enhanced in order to reach better effects of desalinization and desodication. Irrigation with TPME significantly increased soil organic matter, alkali-hydrolyzable nitrogen and available phosphorus due to the abundant organic matter in TPME. Plowing increased soil air circulation, so as to enhance mineralization of organic matter and lead to the loss of organic matter; however, plowing significantly improvedsoil alkali-hydrolyzable nitrogen and available phosphorus. Improvements of physicochemical properties in I-treatment and IP-treatment both boosted soil microbial population and activity. Microbial biomass carbon increased significantly by 327% (I-treatment) and 451% (IP-treatment), while soil respiration increased significantly by 316% (I-treatment) and 386% (IP-treatment). Urease and dehydrogenase activities in both I-treatment and IP-treatment were significantly higher than that in CK. Phosphatase in IP-treatment was significantly higher than that in CK. Compared to I-treatment, IP-treatment improved all of the soil properties except for soil organic matter. The key to remediation of degraded sa- line-alkaline wetlands is to decrease soil salinity and sodicity; thus, irri- gation plus plowing could be an ideal method of soil remediation. 展开更多
关键词 anti-waterlogging ditches degraded saline-alkaline wetlands plowING remediation soil property treated paper mill effluent
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Plowshares Wear Investigation of the Plows Working in Mountainous Conditions Using Statistical Probabilistic Modeling
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作者 Jemal Katsitadze Tadeusz Pawlowski Zaur Phutkaradze 《Journal of Agricultural Science and Technology(A)》 2018年第4期253-257,共5页
A general technique for modeling of the wear of machine parts using the theory of probability and mathematical statistics is developed,which is implemented through the example of plows of agricultural plows.Regulariti... A general technique for modeling of the wear of machine parts using the theory of probability and mathematical statistics is developed,which is implemented through the example of plows of agricultural plows.Regularities of their wear during working under mountainous conditions are established,an adequate probabilistic-statistic mathematical model is obtained,general characteristics of the distribution of wear are determined using statistical moments and their most common(modal)values are determined which allow to substantiate the method of restoring worn parts for the purpose of increasing their life.This technique can also be utilized to study the regularity of wear of parts of other machines. 展开更多
关键词 plow ploughshare WEAR MODELING STATISTICAL PROBABILISTIC model
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Disk plow圆盘犁
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《江苏农机化》 2004年第1期34-34,共1页
关键词 DISK plow圆盘犁 悬挂架 小前犁 圆盘犁体 尾轮 犁辕 刮土刀
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Plowing Ahead
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作者 Yu Nan 《ChinAfrica》 2013年第1期40-41,共2页
ALTHOUGH Zhao Zijian's business card shows his office is in Beijing, he spends half the year on business trips to Africa. Zhao, who hails from central ChinEs Henan Province. has been in the agricultural and construct... ALTHOUGH Zhao Zijian's business card shows his office is in Beijing, he spends half the year on business trips to Africa. Zhao, who hails from central ChinEs Henan Province. has been in the agricultural and construction machinery business for decades, and is now the general manager of China- Africa Machinery Corp. (CAMACO). He is involved in agricultural and construction machinery investment and trade in Africa. 展开更多
关键词 YTO plowing Ahead
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Two material removal modes in chemical mechanical polishing:mechanical plowing vs.chemical bonding 被引量:1
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作者 Yuan WU Liang JIANG +3 位作者 Wenhui LI Jiaxin ZHENG Yushan CHEN Linmao QIAN 《Friction》 SCIE EI CAS CSCD 2024年第5期897-905,共9页
With the rapid development of semiconductors,the number of materials needed to be polished sharply increases.The material properties vary significantly,posing challenges to chemical mechanical polishing(CMP).According... With the rapid development of semiconductors,the number of materials needed to be polished sharply increases.The material properties vary significantly,posing challenges to chemical mechanical polishing(CMP).Accordingly,the study aimed to classify the material removal mechanism.Based on the CMP and atomic force microscopy results,the six representative metals can be preliminarily classified into two groups,presumably due to different material removal modes.From the tribology perspective,the first group of Cu,Co,and Ni may mainly rely on the mechanical plowing effect.After adding H_(2)O_(2),corrosion can be first enhanced and then suppressed,affecting the surface mechanical strength.Consequently,the material removal rate(MRR)and the surface roughness increase and decrease.By comparison,the second group of Ta,Ru,and Ti may primarily depend on the chemical bonding effect.Adding H_(2)O_(2)can promote oxidation,increasing interfacial chemical bonds.Therefore,the MRR increases,and the surface roughness decreases and levels off.In addition,CMP can be regulated by tuning the synergistic effect of oxidation,complexation,and dissolution for mechanical plowing,while tuning the synergistic effect of oxidation and ionic strength for chemical bonding.The findings provide mechanistic insight into the material removal mechanism in CMP. 展开更多
关键词 Chemical mechanical polishing corrosion wear material removal mode mechanical plowing chemical bonding
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Detection of the farmland plow areas using RGB-D images with an improved YOLOv5 model
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作者 Jiangtao Ji Zhihao Han +2 位作者 Kaixuan Zhao Qianwen Li Shucan Du 《International Journal of Agricultural and Biological Engineering》 SCIE 2024年第3期156-165,共10页
Recognition of the boundaries of farmland plow areas has an important guiding role in the operation of intelligent agricultural equipment.To precisely recognize these boundaries,a detection method for unmanned tractor... Recognition of the boundaries of farmland plow areas has an important guiding role in the operation of intelligent agricultural equipment.To precisely recognize these boundaries,a detection method for unmanned tractor plow areas based on RGB-Depth(RGB-D)cameras was proposed,and the feasibility of the detection method was analyzed.This method applied advanced computer vision technology to the field of agricultural automation.Adopting and improving the YOLOv5-seg object segmentation algorithm,first,the Convolutional Block Attention Module(CBAM)was integrated into Concentrated-Comprehensive Convolution Block(C3)to form C3CBAM,thereby enhancing the ability of the network to extract features from plow areas.The GhostConv module was also utilized to reduce parameter and computational complexity.Second,using the depth image information provided by the RGB-D camera combined with the results recognized by the YOLOv5-seg model,the mask image was processed to extract contour boundaries,align the contours with the depth map,and obtain the boundary distance information of the plowed area.Last,based on farmland information,the calculated average boundary distance was corrected,further improving the accuracy of the distance measurements.The experiment results showed that the YOLOv5-seg object segmentation algorithm achieved a recognition accuracy of 99%for plowed areas and that the ranging accuracy improved with decreasing detection distance.The ranging error at 5.5 m was approximately 0.056 m,and the average detection time per frame is 29 ms,which can meet the real-time operational requirements.The results of this study can provide precise guarantees for the autonomous operation of unmanned plowing units. 展开更多
关键词 plow areas RGB-D camera YOLO object segmentation contour boundary average distance
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平行犁组翻扣与旋耕组合式油菜种床制备装置研究
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作者 廖庆喜 张季钦 +3 位作者 张青松 杜文斌 林建新 王立宗 《农业机械学报》 EI CAS CSCD 北大核心 2024年第10期190-201,共12页
针对长江中下游稻-油轮作区土壤黏重板结、秸秆量大,油菜直播机采用普通旋耕时易导致种床耕层浅、秸秆埋覆率低,现有犁旋一体机作业时纵向尺寸大的问题,结合油菜直播农艺要求和合理耕层构建需求,设计了一种平行扣垡犁组,提出了一种“圆... 针对长江中下游稻-油轮作区土壤黏重板结、秸秆量大,油菜直播机采用普通旋耕时易导致种床耕层浅、秸秆埋覆率低,现有犁旋一体机作业时纵向尺寸大的问题,结合油菜直播农艺要求和合理耕层构建需求,设计了一种平行扣垡犁组,提出了一种“圆盘犁刀切茬-压茬,平行犁组翻扣埋茬,旋耕刀辊碎土-匀土”的组合式耕整作业方案。采用直纹面法对扣垡犁的犁体曲面进行设计,构建了犁体曲面解析参数方程,建立了基于离散元方法的耕作部件-土壤-秸秆互作仿真模型,应用EDEM软件开展了二次正交旋转试验,分析了扣垡犁扣垡性能。仿真结果表明:当偏转角θ取12°、元线角差值Δθ取11°时,犁体扣垡效果最优。田间试验结果表明:当耕深为230 mm、作业速度为5.15 km/h时,扣垡犁平均扣垡率为91.3%,有较好埋茬效果;平行扣垡犁组在高茬秸秆工况下有较好的通过性,秸秆平均埋覆率达到82.5%,平均耕深达到218.6 mm,耕深稳定性系数达到90.2%。田间对比试验结果表明:在水稻收获后平均留茬高度为513 mm的工况下,平行犁组翻扣与旋耕组合式油菜种床制备装置平均耕深达229.7 mm,秸秆埋覆率为87.5%,碎土率为89.7%,厢面平整度为31.8 mm,相比于普通旋耕机作业效果,平均耕深增大90.9 mm,秸秆埋覆率和碎土率分别提高7.2个百分点和6.5个百分点,作业质量满足油菜播种要求,符合油菜“深翻埋茬,上松下紧”的种床合理耕层构建要求。 展开更多
关键词 油菜 种床制备装置 犁体曲面 平行扣垡犁组 犁旋
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1LF-5型液压翻转犁的设计与试验
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作者 吴显斌 杜雅刚 纪武鹏 《农机化研究》 北大核心 2024年第4期153-159,166,共8页
为推动玉米秸秆还田保护性耕作农艺的发展,设计了一种集土壤耕作技术、玉米秸秆还田技术于一体的1LF-5型液压翻转犁,一次作业既翻转了土层、松碎了土壤,又可将土壤表层的玉米秸秆与作物残茬翻入土层下,形成隔层进行还田;同时,犁体受到... 为推动玉米秸秆还田保护性耕作农艺的发展,设计了一种集土壤耕作技术、玉米秸秆还田技术于一体的1LF-5型液压翻转犁,一次作业既翻转了土层、松碎了土壤,又可将土壤表层的玉米秸秆与作物残茬翻入土层下,形成隔层进行还田;同时,犁体受到突发外力冲击时,安全装置自动生效,使犁柱绕固定轴栓旋转,从而保护犁体与犁柱的安全。田间试验表明:1LF-5型液压翻转犁的平均耕作深度稳定为33.45cm,平整度为20mm,变异系数在3.166%~3.535%之间;在第1工况下,翻转犁的耕宽平均值为220.75cm,耕宽的变异系数范围为1.21%~1.71%;在第2工况下,翻转犁的耕宽平均值170.1cm,耕作宽度的变异系数范围为1.26%~1.68%;植被覆盖率平均值为89.97%,土垡破碎率为72.27%。机具满足国家标准GB/T14225对于耕作质量的各项要求,也满足翻耕农艺要求。 展开更多
关键词 液压翻转犁 双向翻转机构 玉米秸秆还田 变异系数
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基于LS-DYNA的铧式犁结构优化设计及性能分析
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作者 刘明勇 向雪 +3 位作者 闫春爱 胡成龙 韩新光 欧阳周寰 《农机化研究》 北大核心 2024年第10期153-160,共8页
基于LS-DYNA法建立犁体与土壤的耦合接触有限元模型,讨论不同犁体导曲线、铧刃角、安装角、端点角、耕作速度对耕作过程翻垡效果和犁体应力影响,并进行试验验证。结果表明:椭圆曲面比抛物线曲面耕作时阻力更小、土壤翻垡效果更好,阻力降... 基于LS-DYNA法建立犁体与土壤的耦合接触有限元模型,讨论不同犁体导曲线、铧刃角、安装角、端点角、耕作速度对耕作过程翻垡效果和犁体应力影响,并进行试验验证。结果表明:椭圆曲面比抛物线曲面耕作时阻力更小、土壤翻垡效果更好,阻力降低5.6%,翻垡距离提升14.8%;对犁体前进速度、铧刃角、安装角、端点角进行单因素分析,发现翻垡距离随着速度增加而增加,而随着铧刃角、安装角、端点角呈现出先增大后减小的趋势。因此,通过选取合适的速度与结构参数可以提升铧式犁的翻垡性能,减低犁体阻力。 展开更多
关键词 铧式犁 有限元法 导曲线 翻垡性能
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从清宫内务府汉文奏销档看织染局种种
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作者 崔岩 《丝绸》 CAS CSCD 北大核心 2024年第5期111-117,共7页
文章基于中国第一历史档案馆藏内务府汉文奏销档中关于织染局的七份档案,通过梳理乾隆和嘉庆年间内织染局设置及所辖人、财、物变更等重要事项,分析了清朝中期织染局的沿革历史、人员构成和分工、所用物料、织造品类和使用去向等种种问... 文章基于中国第一历史档案馆藏内务府汉文奏销档中关于织染局的七份档案,通过梳理乾隆和嘉庆年间内织染局设置及所辖人、财、物变更等重要事项,分析了清朝中期织染局的沿革历史、人员构成和分工、所用物料、织造品类和使用去向等种种问题,阐明了织染局作为清代官营织造机构之一的特殊性质和使命,以及与江南三织造的联系和区别。织染局作为清代唯一一处位于京内的官营织造机构,其用丝主要来自江南三织造的供应,在匠役的来源上也与江南地区有着密切联系。由于地理条件及生产规模所限,织染局所产丝织原料质量、生产规模和产品类别均不能与三织造相比。但是作为随传随办的织造机构,织染局能够灵活应变,满足上用和内用的临时需求,因此在清代官营织造机构中具有特殊地位。而且,自乾隆十七年(公元1752年)织染局迁入万寿山演化为耕织图后,不仅通过精简人员和技艺优化来扩大生产品类和提高产品质量,更与皇帝倡导农桑的政策紧密结合,逐渐形成兼具实际生产意义和政策示范性的场所,同时也满足了皇帝对江南田园生活的向往,成为承载官营生产织造和皇帝人文思想的理想机构。 展开更多
关键词 清代宫廷 内务府 汉文奏销档 织染局 耕织图 工匠 染料 生产品类
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天水市旱作区春玉米—冬油菜秸秆带膜翻压还田栽培模式研究
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作者 杨志奇 刘晓东 +3 位作者 张喜平 赵尚文 吕莉莉 周小芹 《现代农业科技》 2024年第9期13-17,共5页
为解决区域内春玉米—冬油菜一膜两用技术中秸秆利用不合理、土壤有机质含量低、有机肥投入不足、化肥施用不合理、土壤水分利用不足、肥料利用率较低等一系列问题,在天水市旱作区开展了春玉米—冬油菜秸秆带膜翻压还田栽培模式研究,以... 为解决区域内春玉米—冬油菜一膜两用技术中秸秆利用不合理、土壤有机质含量低、有机肥投入不足、化肥施用不合理、土壤水分利用不足、肥料利用率较低等一系列问题,在天水市旱作区开展了春玉米—冬油菜秸秆带膜翻压还田栽培模式研究,以期为区域内化肥减施、地力提升和农业可持续发展提供依据。结果表明,秸秆粉碎带膜翻压还田可以提高玉米籽粒产量7.96%、冬油菜籽粒产量9.91%,增加0~20 cm土壤有机质、全磷、有效磷含量(分别增加2.53 g/kg、0.08 g/kg、10.93 mg/kg),缓冲土壤pH值,影响土壤速效钾、硝态氮和铵态氮水平。 展开更多
关键词 春玉米 冬油菜 一膜两用 秸秆带膜翻压还田 产量 土壤养分 旱作区 甘肃天水
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西南喀斯特地貌区采煤沉陷对稻田的影响研究
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作者 成六三 《地下水》 2024年第1期120-124,共5页
为了研究分析采煤沉陷对稻田造成的影响,本文对比分析了采煤沉陷区内正常与非常稻田的土壤物理特性、犁底层入渗参数、水稻生长需水量以及生物和产量等因素。研究结果表明:在西南山地喀斯特地貌区,(1)采煤沉陷对稻田土壤的容重、孔隙度... 为了研究分析采煤沉陷对稻田造成的影响,本文对比分析了采煤沉陷区内正常与非常稻田的土壤物理特性、犁底层入渗参数、水稻生长需水量以及生物和产量等因素。研究结果表明:在西南山地喀斯特地貌区,(1)采煤沉陷对稻田土壤的容重、孔隙度、机械组成影响不大,但影响土壤含水率较明显;(2)采煤沉陷导致稻田犁底层不同损坏,土壤入渗系数超过正常稻田犁底层土壤入渗系数10倍左右;(3)每公顷非正常稻田生长需水量比正常稻田多26.7 m^(3)水量;(4)每公顷正常稻田的产量和秸秆干重比非正常稻田分别多出3100 kg和1200 kg。而正常稻田的单株稻根干重比非正常稻田多1.74 g。总之,在西南山地喀斯特地貌区采煤沉陷已严重影响了稻田的正常生产,特别是稻田犁底层方面的损坏,这对于区域进行稻田生态复垦和社会协调稳定都具有理论与实践价值。 展开更多
关键词 土地复垦 水田漏水 犁底层 土壤水分
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基于犁式卸料器卸煤的筒仓应急排料系统
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作者 贾光华 《电站辅机》 2024年第3期31-34,共4页
针对早期建成的筒仓没有惰化保护系统,经常出现由于筒仓使用管理不当而导致储煤自燃且难以处置的问题,提出了基于犁式卸料器卸煤的筒仓储煤自燃应急排料系统的处置方案。该方案实施后取得了良好的效果,可为同类筒仓提供参考。同时,提出... 针对早期建成的筒仓没有惰化保护系统,经常出现由于筒仓使用管理不当而导致储煤自燃且难以处置的问题,提出了基于犁式卸料器卸煤的筒仓储煤自燃应急排料系统的处置方案。该方案实施后取得了良好的效果,可为同类筒仓提供参考。同时,提出了即使新建电厂设计了筒仓惰化保护系统,也应在输煤系统的适当部位设计犁式卸料器或其他适宜的应急排料系统的建议,保障筒仓安全。 展开更多
关键词 筒仓 自燃 犁式卸料器 应急 排料
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1990—2022年天山北坡地区不同开垦年限耕层土壤盐分变化
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作者 张彬 郑新军 +4 位作者 王玉刚 唐立松 李彦 杜澜 田胜川 《干旱区研究》 CSCD 北大核心 2024年第9期1435-1445,共11页
近年来,随着频繁的土地利用变化和大量耕地的开垦,土壤盐渍化已成为导致天山北坡耕地质量退化、阻碍绿洲农业发展的环境因素。本研究基于翔实的调查数据资料、土壤实测数据和中国土地覆盖数据集(CLCD),比较传统插值模型和随机森林插值... 近年来,随着频繁的土地利用变化和大量耕地的开垦,土壤盐渍化已成为导致天山北坡耕地质量退化、阻碍绿洲农业发展的环境因素。本研究基于翔实的调查数据资料、土壤实测数据和中国土地覆盖数据集(CLCD),比较传统插值模型和随机森林插值模型对耕层土壤(0~30 cm)含盐量插值的优缺点;选取精度最高的定量预测模型对天山北坡地区耕层土壤含盐量定量预测,得到耕层土壤含盐量分布变化特征;以空间换时间,将近30 a新开垦耕地耕层土壤含盐量进行比较,分析开垦年限对土壤含盐量的影响。结果表明:(1)与传统的插值方法相比,随机森林算法能够更准确地预测盐渍化土地的土壤盐分分布情况。(2)天山北坡地区,耕层土壤含盐量存在较大空间异质性,即高海拔地区土体中的盐分会随着径流的淋溶,在低海拔的河流下游尾闾或低洼区靠近沙漠一侧积聚。(3)随着开垦年限的延长,天山北坡地区耕层土壤含盐量总体呈现下降的趋势,且土壤盐渍化程度倾向于聚集在一个中等的水平上,趋向于平衡或“中心化”。本研究增进了对当前耕地盐渍化状况及从原始荒地开垦到耕地后耕层土壤盐分变化历程的理解。这为干旱区备用土地资源的开发、管理和有效利用提供了理论支撑,并为农业的持续发展提供了科学依据。 展开更多
关键词 随机森林 耕层土壤盐渍化 开垦年限 时空变化 天山北坡
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不同耕作灌溉和有机肥替代下稻田有机碳和氮磷潜在排放特征
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作者 赵家阳 于孟康 +4 位作者 马玉珠 段婧婧 于建光 薛利红 杨林章 《环境工程技术学报》 CAS CSCD 北大核心 2024年第6期1655-1664,共10页
通过盆钵试验研究了不同耕作条件、不同灌溉方式和基肥期有机肥替代对水稻田面水有机碳与氮磷浓度、潜在可排放量及水稻产量的影响。结果表明:1)浅水灌溉相比常规灌溉,在旋耕时各项指标的平均可排放量均呈现不同程度的降低趋势,其中化... 通过盆钵试验研究了不同耕作条件、不同灌溉方式和基肥期有机肥替代对水稻田面水有机碳与氮磷浓度、潜在可排放量及水稻产量的影响。结果表明:1)浅水灌溉相比常规灌溉,在旋耕时各项指标的平均可排放量均呈现不同程度的降低趋势,其中化学需氧量(COD)降低43.43%,可溶性有机碳(DOC)降低43.19%,总氮(TN)降低46.52%,总磷(TP)降低60.34%;而翻耕时稻田田面水的COD、DOC、TN和TP浓度分别降低22.73%、41.58%、31.58%和31.25%。2)翻耕相比旋耕,在常规灌溉时稻田田面水COD、DOC和TP的平均可排放量分别降低16.02%、15.67%和23.71%;在浅水灌溉时稻田田面水COD、DOC和TP的平均可排放量分别降低43.42%、16.81%和13.93%。3)浅水灌溉下有机肥替代氮肥用作基肥的田面水COD、DOC和TP的平均可排放量无显著差异(P>0.05);浅水灌溉相比常规灌溉,在旋耕和翻耕时水稻产量分别减产20.63%和6.88%。总之,浅水灌溉田面水碳、氮、磷排放风险显著低于常规灌溉,翻耕可以有效降低田面水碳、氮、磷排放风险,从稻田田面水防控和产量角度,浅水灌溉并翻耕能够在保证水稻产量的同时有效降低田面水养分流失风险。研究结果可为稻田投入品优化施用和田间水分及养分管理提供技术支撑。 展开更多
关键词 耕作条件 有机肥 浅水灌溉 翻耕 田面水 有机碳 氮磷
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犁刀混合机动轴密封失效原因分析与研究
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作者 邹俊伟 李毅波 +1 位作者 姜方鸿 宋玉梁 《流体机械》 CSCD 北大核心 2024年第7期63-68,共6页
针对犁刀混合机工作介质为粉末物料时动轴密封失效问题,根据动轴密封试验结果及动轴密封原理展开失效原因分析。结果表明,密封气体出口压力大于工作介质压力、密封气体出口压力沿圆周方向均匀性、气密封通道宽度尺寸b沿圆周方向均匀性等... 针对犁刀混合机工作介质为粉末物料时动轴密封失效问题,根据动轴密封试验结果及动轴密封原理展开失效原因分析。结果表明,密封气体出口压力大于工作介质压力、密封气体出口压力沿圆周方向均匀性、气密封通道宽度尺寸b沿圆周方向均匀性等3个条件,是保证犁刀混合机动轴密封性能的关键。在此基础上,再采用理论计算及有限元仿真相结合的方法对动轴密封失效原因展开进一步分析,根据分析结果分别从动轴密封设计、制造角度提出了犁刀混合机动轴密封失效的解决方法;最后通过试验验证了解决方法的正确性。试验结果表明,在动轴密封密封气体出口压力、配气环等设计符合要求的情况下,气密封通道宽度尺寸b沿圆周方向的偏心量为0.1 mm时,其连续密封时间分别是偏心量为0.3,0.6 mm时的3倍、13倍,即通过降低气密封通道宽度尺寸b沿圆周方向的偏心量,对提高动轴密封装置的密封性能有显著效果。研究成果对犁刀混合机动轴密封设计及应用具有一定指导意义。 展开更多
关键词 犁刀混合机 动轴密封 粉末物料 原因分析 试验研究
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高速犁体曲面结构参数对耕作阻力的影响研究
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作者 赵雪彦 司冰权 +2 位作者 宋正河 陈雪冬 张有强 《动力学与控制学报》 2024年第4期86-96,共11页
针对我国铧式犁高速作业时耕作阻力大、耕地质量差等问题,本文研究了高速犁体曲面结构参数对耕作阻力的影响.首先,分析了基于水平直元线法的高速犁体曲面形成过程,得出对高速犁体曲面作业性能影响较大的结构参数.然后,基于离散元法建立... 针对我国铧式犁高速作业时耕作阻力大、耕地质量差等问题,本文研究了高速犁体曲面结构参数对耕作阻力的影响.首先,分析了基于水平直元线法的高速犁体曲面形成过程,得出对高速犁体曲面作业性能影响较大的结构参数.然后,基于离散元法建立了高速犁体曲面-土壤互作模型,并通过土槽试验和仿真试验验证了该模型的合理性.最后,分别研究了铧刃角θ、导曲线开度l、犁铧安装角ε和高度偏差量ΔH等结构参数对耕作阻力的影响规律.研究结果表明:随着铧刃角的增大,耕作阻力以较快速度增大;随着导曲线开度的增大,耕作阻力逐渐减小;随着犁铧安装角的增大,耕作阻力在较小范围内波动;随着高度偏差量的增大,耕作阻力缓慢增大. 展开更多
关键词 高速犁体曲面 水平直元线法 离散元法 耕作阻力
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