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Precision Agriculture - This study reviewed research published after 1990 on the economics of agricultural mechatronic automation and robotics, and identified research gaps. A systematic search was...  相似文献   
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为探讨空心菜和薄荷在不同种植环境下的作物生长量和养分吸收量,选择入星云湖河水及其附近农田为种植载体,开展空心菜、薄荷的漂浮水栽与土栽的比较试验.结果表明,空心菜水栽的植株高度、分枝数及茎叶产量分别为41.3 cm、6.2个及4.17 kg·m-2,比土栽的提高45.9%、37.8%及59.8%;水栽空心菜的茎叶全N含量...  相似文献   
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OBJECTIVE: To identify the duration and potential mechanisms of analgesia following extracorporeal shock wave therapy (ESWT) and radial pressure wave therapy (RPWT) in limbs of horses and sheep. ANIMALS: 6 horses and 30 sheep. PROCEDURE: An electrical stimulus was used to identify the nociceptive threshold for each horse daily for 3 days before treatment (baseline) with ESWT or RPWT, 8 hours after treatment, and at 24-hour intervals for 7 days after treatment. Testing was conducted for the treatment field (midmetacarpus or midmetatarsus) and nerve field (medial and lateral forelimb heel bulbs) distal to a treatment site that included the nerve on the abaxial surface of the proximal sesamoid bone. All 4 limbs of 30 sheep were treated with ESWT, RPWT, or a sham treatment. Two sheep were euthanatized daily and tissue harvested for histologic evaluation of nerves, and concentrations of substance P and calcitonin gene-related peptide were measured in the skin and periosteum. RESULTS: Values did not differ significantly between baseline and after treatment for the treatment field or nerve field sensation. There was a large difference in the slope when data for horses were plotted for the first 3 days after treatment, compared with the slope for days 4 to 7 after treatment. No differences were found in neuropeptide concentrations after treatment of the sheep, but there was an inflammatory response in the treated nerves. CONCLUSIONS AND CLINICAL RELEVANCE: A small cutaneous analgesic effect may exist at the treatment site for approximately 3 days after ESWT or RPWT in horses.  相似文献   
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林区步行最优路径分析方法   总被引:1,自引:0,他引:1  
针对林区步行环境的复杂性与寻路目标的多样性,提出了林区步行最优路径分析方法。首先,引入了可步行性的概念,建立综合可步行性栅格,将特定的林区步行最优路径分析问题转化为避让不可行域、在可行域与易行域中计算多目标最小成本路径的问题;随后,将步行成本分为地形成本与地物成本,分别计算单因素成本并加权组合为综合步行成本,将多目标优化问题简化为单目标问题进行求解;最后,基于综合可步行性栅格,扩展了邻接表的数据结构,利用8方向邻域模式建立栅格单元间的邻接关系并计算步行成本,构建栅格网络模型。采用Dijkstra算法实现林区步行最优路径的求解。试验结果表明:本方法能够融合开放空间和离散路网,对林区步行环境进行建模,同时降低多个寻路目标的路径成本,使结果偏重于主要目标,具有一定的适用性。  相似文献   
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随着人们对海洋生物资源研究的日益关注,藻类生物资源的挖掘也越来越受到重视,近年来其在农业领域的应用和价值也日益凸显。目前,人们对藻类资源在农业中的应用研究主要集中在对藻类生物肥料和生物刺激剂的探索,即为农作物寻找新的肥料来源,但对其作用机制的研究还缺乏总结。为此,本文综述了国内外相关研究进展,重点介绍了藻类资源在农业种植业中的利用,阐述了藻类细胞及其产物在农业工程中的应用与发展,包括藻类作为生物肥料和生物刺激剂、藻类资源在农业环境修复以及农作物产品保鲜等方面的应用。此外,本文还总结了藻类资源在农业应用中的主要机理:①藻类的固碳、固氮以及解磷作用,可提高土壤营养物质含量,调节土壤微生物活力,促进植物生长;②藻类分泌的胞外聚合物有助于改善土壤荒漠化及盐碱化,降低农药污染风险和提高土壤肥料利用效率;③藻类细胞的生物吸附性有助于重金属污染土壤的修复;④海藻多糖的抑菌、抗病毒和保鲜功能等。总而言之,藻类资源在农业种植业中具有广阔的应用前景和巨大的开发价值。未来的研究应着眼于藻类细胞活性物质的促生长机理和藻类资源的田间规模评价,重视分子生物学技术的应用,挖掘更多样化的藻类应用潜力,为藻类生物质的开发和农业可持续发展提供理论依据。  相似文献   
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【目的】为优化林区瞭望塔布局与建设时序,提高瞭望塔网络建设效率。【方法】以北京郊区某林场为实验点,针对瞭望塔网络建设的空间性、阶段性和动态性等特点,设计基于顶点法的最大监测面积模型(Max-MAM),利用Greedy算法求解近似最优布局方案;设计基于熵权法的动态多属性建设时序模型(DMACTSM),求解近似最优布局方案下的综合最优建设时序。【结果】顶点法共提取到38个备选点;用Max-MAM优选出最优布局方案■,可使瞭望塔网络的监测覆盖面积最大,约71.47%;用DMACTSM模型获得最优建设时序为a_(29)、a_(26)、a_(12)、a_6、a_(36)和a_(18),可使瞭望塔网络建设过程中综合效益最优。【结论】Max-MAM和DMACTSM能够调整建设时序,解决建设时序最优问题,结合地理信息系统(GIS)实现瞭望塔网络布局优化;调整后的建设时序在增长监测面积、交通、坡度、已有建筑情况等方面综合最优。图6表3参16  相似文献   
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The impact of cooking and digestion on the antioxidant capacity (AC), estimated total phenolic content (TPC) and anti-inflammatory activity (AA) of culinary spices was determined to investigate their significance as dietary contributors to these properties. Extracts of uncooked (U), cooked (C) and cooked and digested, in vitro, (D) cinnamon, clove and nutmeg were prepared and the TPC, AC and AA, specifically the inhibition of cyclo-oxygenase 2 (COX-2) and the amount of prostaglandin (PG) synthesized, were determined. Compared to their uncooked (U) counterparts, the following changes were statistically significant: the AC and TPC for (C) clove, and the TPC for (D) clove decreased, the TPC for (D) clove increased, the TPC for (C) nutmeg increased, and the AC and TPC for (D) nutmeg increased, and the TPC for (C) and (D) nutmeg increased. All the spices achieved near 100 % inhibition of COX-2 which was associated with the inhibition of the amount of PG synthesized. Based on estimated levels of ingestion, cinnamon possesses a much higher AC than clove and nutmeg because it is typically used in larger quantities. For AA, (U, C and D) cinnamon and clove maintain near 100 % inhibition of COX-2 but only the inhibitory potential of (D) nutmeg could be ascertained (70 %). Cooking and digestion alter the TPC and AC of these spices although the changes are not consistent between spices or across treatments. In contrast to AC, significant AA is likely to be present in these spices at amounts used in cooking.  相似文献   
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A method for the rapid propagation of raspberry (Rubus idaeus cultivar ‘Heritage’) is described, involving tip-culture, shoot elongation, multiplication by small cuttings, root initiation and transfer of plants to soil.  相似文献   
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