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基于势能平衡的图像骨架抽取算法 被引量:6
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作者 曹铁勇 杨吉斌 张雄伟 《东南大学学报(自然科学版)》 EI CAS CSCD 北大核心 2003年第6期724-727,共4页
基于骨架的基本特征和势能的概念 ,提出了一种基于势能平衡方式的二值图像骨架抽取算法 .将抽取对象的边缘点作为零势能的等势点 ,计算出处于势能平衡点上的基本骨架点 ,并据此通过向势能小处延伸的方式构建出骨架 ,还解决了由于各点周... 基于骨架的基本特征和势能的概念 ,提出了一种基于势能平衡方式的二值图像骨架抽取算法 .将抽取对象的边缘点作为零势能的等势点 ,计算出处于势能平衡点上的基本骨架点 ,并据此通过向势能小处延伸的方式构建出骨架 ,还解决了由于各点周围参考零势能点数量不同而带来的各点势能值间难以比较的问题 .通过计算机模拟显示 ,本算法对于边界噪声影响不太敏感 。 展开更多
关键词 图像处理 骨架 细化 势能平衡
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新型双滚筒长冲程抽油机设计 被引量:10
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作者 刘剑辉 杨松 马健强 《石油矿场机械》 2009年第12期56-58,共3页
介绍了一种新型双滚筒式长冲程抽油机的工作原理及其势能平衡原理,并对平衡系统做了力学分析,进行了平衡设计,使得电机容量达到最小,具有节能增效的优点。
关键词 长冲程抽油机 势能平衡 双滚筒 节能
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滑坡时空演化规律及覆管力学响应研究 被引量:7
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作者 王金安 周家兴 李飞 《岩土力学》 EI CAS CSCD 北大核心 2020年第7期2155-2167,2178,共14页
山体滑坡是威胁天然气管道安全运营的主要地质灾害,研究适应于滑坡演化规律及覆管力学响应状态的分析方法具有重要的工程意义。为此,首先采用坡体系统(阻滑段-下滑段)总势能平衡方程,即拉格朗日变分方程,并基于最小势能原理,获得坡体失... 山体滑坡是威胁天然气管道安全运营的主要地质灾害,研究适应于滑坡演化规律及覆管力学响应状态的分析方法具有重要的工程意义。为此,首先采用坡体系统(阻滑段-下滑段)总势能平衡方程,即拉格朗日变分方程,并基于最小势能原理,获得坡体失稳滑移的临界条件——下滑段应变能释放量等于阻滑段破裂贯通所需要的应变能时,坡体即发生滑移,坡体内部储存的应变能转化为动能。一方面,根据滑动全过程中的岩土体颗粒与管道外壁接触关系,提出了滑坡两阶段的管道力学响应模式;另一方面,考虑岩土体颗粒的碎散度,分别构建岩质滑坡作用下管道的均匀受力模式及土质边坡管道的非均匀受力模式。鉴于此,从小尺度管土相互作用的力学响应出发,推导出岩质边坡与土质边坡滑动前后阶段的管道弹性部分受力表达式。最后,以川气东送EES244段天然气管道跨越滑坡为研究对象,建立了边坡系统总势能方程,分析出坡体的变形、失稳及滑移情况,计算出管道在不同滑动阶段的应力值,对管道的安全性进行了评价。同时,采用数值模拟的方法,从整体大尺度角度对全管段进行受力分析与安全性校核。结果表明:滑动区与未滑动区的交界面附近管道出现应力突变,滑动区内部应力小幅度增加,但整体处于安全稳定状态。因此,采用的小尺度理论计算与大尺度整体数值模拟的研究方法,对拟建管道前期设计、现役管道安全评价和后期管道维修等具有指导意义及实用价值。 展开更多
关键词 时空演化 阻滑段 覆管 势能平衡方程 尺度
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经深冷处理提高黄铜耐盐水腐蚀性 被引量:8
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作者 唐中华 《西南科技大学学报》 CAS 2003年第1期52-54,共3页
黄铜常作为制冰盐水池蒸发器,载冷剂溶液蒸发器,舰船海水冷凝器的管子材料。以往,为了提高黄铜冷凝管耐腐蚀性所采取的方法有加保护电流,牺牲阳极等措施。本文通过实验研究得出经深冷处理过的黄铜比未经深冷处理的黄铜有更耐腐蚀性的结论。
关键词 黄铜 耐盐水腐蚀性 深冷处理 抗腐蚀能力 显微结构 势能平衡
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宇宙生命的狂想曲
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作者 刘八一 李晓勇 《现代物业(中旬刊)》 2010年第10期103-103,99,共2页
宇宙基本运动体的运动形成的生命能势的产生;天体、天体系的形成;天体系生命环境的形成,地球上有机生命的形成。
关键词 中子组 能势态 势能平衡
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THE BALANCE BETWEEN SUPPLY AND DEMAND OF WATER RESOURCES AND THE WATER-SAVING POTENTIAL FOR AGRICULTURE IN THE HEXI CORRIDOR 被引量:9
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作者 GAOQian-zhao DUHu-lin 《Chinese Geographical Science》 SCIE CSCD 2002年第1期23-29,共7页
The Hexi Corridor is an important base of agriculture development inNorthwest China. According to recent statistics, there are 65. 94 x 10~8m^3 of water resourcesavailable in the Hexi Corridor. At present, net consump... The Hexi Corridor is an important base of agriculture development inNorthwest China. According to recent statistics, there are 65. 94 x 10~8m^3 of water resourcesavailable in the Hexi Corridor. At present, net consumption in development and utilization is 43. 33x 10~8m^3. Water supply and demand reach a balance on the recent level of production, but loss ofevaporation and evapotranspiration is as much as 25. 69 x 1010~8m^3. So net use efficiency of waterresources is 59% Based on analyzing balance between water and land considering ecologicalenvironment at present, there exists the serious water shortage in the Shiyang River system whereirrigation lands have overloaded. There is a comparative balance between supply and demand of waterresource in the Heihe River system; and the Sule River system has some surplus water to extendirrigation land. Use of agriculture water accounts for 83. 3% and ecological forest and grass for 6.9% . The Hexi Corridor still has a great potential for water saving in agriculture production.Water-saving efficiency of irrigation is about 10% by using such traditional technologies as furrowand border-dike irrigation and small check irrigation, and water-saving with plastic film cover andtechniques of advanced sprinkler and drip/micro irrigation etc. can save more than 60% of irrigatedwater. Incremental irrigation area for water-saving potential in the Hexi Corridor has beenestimated as 56% - 197% to original irrigation area. So the second water sources can be developedfrom water saving agriculture in the Hexi Corridor under Development of the Western Part of China inlarge scale. This potential can be realized step by step through developing the water-savingmeasures, improving the ecological condition of oasis agriculture, and optimizing allocation ofwater resources in three river systems. 展开更多
关键词 water resources balance between supply and demand water-saving potential ofagriculture hexi corridor
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Effective Potential of a Two-State Model for Molecular Motor
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作者 HANYing-Rong ZHAOTong-Jun +1 位作者 ZHAN-Yong YANWei-Li 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第2期377-381,共5页
We study force generation and motion of molecular motors using a simple two-state model in the paper.Asymmetric and periodic potential is adopted to describe the interaction between motor proteins and filaments that a... We study force generation and motion of molecular motors using a simple two-state model in the paper.Asymmetric and periodic potential is adopted to describe the interaction between motor proteins and filaments that are periodic and polar. The current and the slope of the effective potential as functions of the temperature and transition rates are calculated in the two-state model. The ratio of the slope of the effective potential to the current is also calculated. It is shown that the directed motion of motor proteins is relevant to the effective potential. The slope of the effective potential corresponds to an average force. The non-vanishing force therefore implies that detailed balance is broken in the process of transition between different states. 展开更多
关键词 Brownian particle directed motion Fokker-Planck equation effective potential detailed balance
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System to Control Upright Posture with Alcoholic Intake 被引量:1
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作者 Hiroki Takada Shinichi Taniguchi +1 位作者 Yuuki Shimizu Takayuki Hirata 《Journal of Mathematics and System Science》 2012年第7期447-453,共7页
Equilibrium function in the cerebellum (vestibulo-cerebellar system) can deteriorate under the influence of alcohol. In the Romberg posture, the center of gravity, which was measured every 50 ms by stabilometry, app... Equilibrium function in the cerebellum (vestibulo-cerebellar system) can deteriorate under the influence of alcohol. In the Romberg posture, the center of gravity, which was measured every 50 ms by stabilometry, appeared to shift with alcohol ingestion. In the previous study, a locus in the center of gravity (stabilogram) was converted to values of statistical indices such as area of sway, total locus length, sparse density, and locus length per unit area, although these indices could not always distinguish between the stabilograms sampled from seven healthy young males in sober and intoxicated states. This measurement was made with an AMTI force plate. In this study, "translation error" was estimated in a d-dimensional embedding space in order to compare stabilograms recorded before and after the ingestion of doubly diluted brandy in 30 s (1 ≤ d ≤ 10). The authors succeeded in validating stochastic differential equations as a mathematical model of the body sway. Although the postural control system shows different patterns in the lateral and anterior-posterior directions, the randomness in the model was preserved after alcohol intake and significantly increased in the medial/lateral direction. Visual information referred by the postural conlrol system when standing might be interfered by the effects of intoxication, which was regarded as disturbance. The possibility of detecting alcohol-ingestion-induced reduction of the equilibrium function and its recovery process are also suggested in this paper. This method is considered to be useful to diagnose the disorders of the vestibulo-cerebellar system. 展开更多
关键词 Stabilogram alcoholic intake SPD (sparse density) translation error SDE (stochastic differential equation).
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